Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Porphyromonas gingivalis is commonly known as one of the major pathogens contributing to periodontitis, and its persistent infection may increase the risk for the disease. The proinflammatory mediators, including IL-6, TNF-α, and cyclooxygenase-2 (COX-2)/PGE2, are closely associated with progression of periodontitis. In this study, we focused on the cysteine protease "gingipains," lysine-specific gingipain, arginine-specific gingipain (Rgp) A, and RgpB, produced by P. gingivalis, and used the wild-type strain and several gene-deletion mutants (rgpA, rgpB, kgp, and fimA) to elucidate the involvement of gingipains in COX-2 expression and PGE2 production. We infected human monocytes, which are THP-1 cells and primary monocytes, with these bacterial strains and found that gingipains were involved in induction of COX-2 expression and PGE2 production. We have shown that the protease activity of gingipains was crucial for these events by using gingipain inhibitors. Furthermore, activation of ERK1/2 and IκB kinase was required for gingipain-induced COX-2 expression/PGE2 production, and these kinases activated two transcription factors, c-Jun/c-Fos (AP-1) and NF-κB p65, respectively. In particular, these data suggest that gingipain-induced c-Fos expression via ERK is essential for AP-1 formation with c-Jun, and activation of AP-1 and NF-κB p65 plays a central role in COX-2 expression/PGE2 production. Thus, we show the (to our knowledge) novel finding that gingipains with the protease activity from P. gingivalis induce COX-2 expression and PGE2 production via activation of MEK/ERK/AP-1 and IκB kinase/NF-κB p65 in human monocytes. Hence it is likely that gingipains closely contribute to the inflammation of periodontal tissues.

DOI： 10.4049/jimmunol.2100866

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/1348-0421.12944

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/1348-0421.12944

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Tuberculosis is a communicable disease caused by Mycobacterium tuberculosis which primarily infects macrophages and establishes intracellular parasitism. A mycobacterial virulence factor Zn2+ metalloprotease 1 (Zmp1) is known to suppress interleukin (IL)-1β production by inhibiting caspase-1 resulting in phagosome maturation arrest. However, the molecular mechanism of caspase-1 inhibition by Zmp1 is still elusive. Here, we identified GRIM-19 (also known as NDUFA13), an essential subunit of mitochondrial respiratory chain complex I, as a novel Zmp1-binding protein. Using the CRISPR/Cas9 system, we generated GRIM-19 knockout murine macrophage cell line J774.1 and found that GRIM-19 is essential for IL-1β production during mycobacterial infection as well as in response to NLRP3 inflammasome-activating stimuli such as extracellular ATP or nigericin. We also found that GRIM-19 is required for the generation of mitochondrial reactive oxygen species and NLRP3-dependent activation of caspase-1. Loss of GRIM-19 or forced expression of Zmp1 resulted in a decrease in mitochondrial membrane potential. Our study revealed a previously unrecognized role of GRIM-19 as an essential regulator of NLRP3 inflammasome and a molecular mechanism underlying Zmp1-mediated suppression of IL-1β production during mycobacterial infection.

DOI： 10.1096/fj.202101074rr

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1096/fj.202101074RR

Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Genomic analysis revealed that the vaccine seed lot of Mycobacterium bovis bacillus Calmette-Guérin (BCG) Tokyo 172 contains two subclones (types I and II), but their phenotypic differences have not been elucidated. In this study, we compared the susceptibility of bacilli types I and II to oxidative stress in vitro and within host cells. Notably, the subclones displayed similar superoxide dismutase activity; however, foam height in the catalase test and lysate catalase/peroxidase activity were higher for type I bacilli than for type II bacilli. Additionally, type I bacilli were less susceptible to hydrogen peroxide (H2O2) than type II bacilli. After exposure to H2O2, antioxidative stress response genes katG, ahpC, sodA, and trxA were more strongly induced in type I bacilli than in type II bacilli. Further, we investigated cell survival in macrophages. Fewer type II bacilli were recovered than type I bacilli. However, in the presence of apocynin, a specific inhibitor of NADPH oxidase, type II recovery was greater than that of type I. The production of interleukin 1β (IL-1β), IL-12 p40, and tumor necrosis factor alpha (TNF-α) was higher in type I bacillus-infected macrophages than in type II bacillus-infected macrophages. The proportions of type I and type II bacilli in vaccine lots over 3 years (100 lots) were 97.6% ± 1.5% and 2.4% ± 1.5%, respectively. The study results illustrated that type I bacilli are more resistant to oxidative stress than type II bacilli. Overall, these findings provide important information in terms of the quality control and safety of BCG Tokyo 172 vaccine.IMPORTANCE This study revealed the difference of in vivo and in vitro antioxidative stress properties of BCG Tokyo 172 types I and II as one of the bacteriological characteristics. In particular, the bacilli exhibited differences in catalase/peroxidase activity, which could explain their different protective effects against infection. The differences correlated with survival in the host cell and the production of proinflammatory cytokines to protect against infection by Mycobacterium tuberculosis The proportion of bacilli types I and II in all commercial lots of BCG Tokyo 172 over 3 years (100 lots) was constant. The findings also highlighted the importance of analyzing their content for quality control during vaccine production.

DOI： 10.1128/mSphere.00111-21

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Microbiology Society  

<italic>
<named-content content-type="subspecies">
<ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.14878" xlink:type="simple">Mycobacterium avium</ext-link>
</named-content>
</italic> subspecies <italic>
<named-content content-type="subspecies">
<ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.14878" xlink:type="simple">hominissuis</ext-link>
</named-content>
</italic> (MAH) is a pathogen that causes various non-tuberculous mycobacterial diseases in humans and animals worldwide. Among the genus, MAH is characterized by relatively slow growth. Here, we isolated a rapidly growing variant of the MAH 104 strain. The variant strain (named N104) exhibited an enhanced growth rate and higher motility compared to the parent MAH 104 strain (P104). Whole-genome sequencing analysis of N104 revealed the loss of the stop codon of <italic>MAV_RS14660</italic> due to a single nucleotide replacement, resulting in the substitution of the codon for tryptophan. Notably, exclusion of the stop codon ligated the open reading frames and caused the fusion of two adjacent proteins. A revertant parent strain, in which a mutation was introduced to restore the stop codon, revealed that elimination of the stop codon in <italic>MAV_RS14660</italic> was responsible for the N104 phenotype. Furthermore, we analysed the phenotypes of the parent and mutated strains by determining the functions of the <italic>MAV_RS14660</italic> and <italic>MAV_RS14655</italic> coding regions flanking the stop codon. The mutant strains, expected to express a fusion protein, exhibited increased resistance to antimicrobial drugs and exogenous copper toxicity compared to that of the parent strains. These findings suggest that the fusion of the <italic>MAV_RS14660</italic>- and <italic>MAV_RS14655</italic>-encoding regions in the mutant N104 strain could be related to the modified functions of these intrinsic proteins.

DOI： 10.1099/mic.0.001007

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Porphyromonas gulae, an animal-derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS), and proteases. We previously reported that its invasive efficiency was dependent on fimbriae types. In addition, P. gulae LPS increased inflammatory responses via toll-like receptors. The present study was conducted to investigate the involvement of P. gulae proteases in bacterial and host cell biology. P. gulae strains showed an ability to agglutinate mouse erythrocytes and also demonstrated coaggregation with Actinomyces viscosus, while the protease inhibitors antipain, PMSF, TLCK, and leupeptin diminished P. gulae proteolytic activity, resulting in inhibition of hemagglutination and coaggregation with A. viscosus. In addition, specific proteinase inhibitors were found to reduce bacterial cell growth. P. gulae inhibited Ca9-22 cell proliferation in a multiplicity of infection- and time-dependent manner. Additionally, P. gulae-induced decreases in cell contact and adhesion-related proteins were accompanied by a marked change in cell morphology from well spread to rounded. In contrast, inhibition of protease activity prevented degradation of proteins, such as E-cadherin, β-catenin, and focal adhesion kinase, and also blocked inhibition of cell proliferation. Together, these results indicate suppression of the amount of human proteins, such as γ-globulin, fibrinogen and fibronectin, by P. gulae proteases, suggesting that a novel protease complex contributes to bacterial virulence. This article is protected by copyright. All rights reserved.

DOI： 10.1111/cmi.13312

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.job.2020.09.007

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.

DOI： 10.1016/j.ymthe.2019.09.023

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

The periodontal pathogen Porphyromonas gingivalis shows colonial pigmentation on blood agar and produces gingipains (Kgp, RgpA, and RgpB), cysteine proteases involved in an organism's virulence and pigmentation. We showed previously that deletion of the PGN_0300 gene abolished the pigmentation activity and reduced the proteolytic activity of gingipains. The role of the PGN_0297 gene, which consists of an operon with the PGN_0300 gene, is unclear. Herein we examined the effect of PGN_0297 gene deletion on the pigmentation and proteolytic activities and transcriptional levels of gingipains. A PGN_0297 gene deletion mutant (ΔPGN_0297) did not exhibit the pigmentation. The proteolytic activity of the gingipains was decreased in the culture supernatant and on the cell surface of ΔPGN_0297. The mutant ΔPGN_0297 failed to attenuate Akt phosphorylation at Thr308 and Ser473, but both phosphorylations were attenuated in the wild-type and its complementation strain. The deletion of PGN_0297 gene did not substantially affect the transcriptional levels of the gingipain genes kgp, rgpA, and rgpB. Taken together, these results indicate that PGN_0297 is closely involved in the secretion and maturation of gingipains.

DOI： 10.18926/AMO/56933

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.celrep.2019.03.056

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DOI： 10.1128/JCM.01760-18

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It has been well known in humans that eosinophil infiltration into the site of inflammation and eosinophilia occur in mycobacterial infections. However, the role of eosinophils against the mycobacterium is unclear. We showed in previous study that in situ mouse eosinophils infiltrated into tissues produce α-defensin, an anti-bacterial peptide. We investigated in this study whether eosinophils reacting to mycobacteria produce α-defensin in mice and whether it can be used as a model. We showed that mycobacterial infection induced blood eosinophilia and infiltration of α-defensin producing eosinophils that to surround mycobacteria at the site of infection. These findings were usually seen during human mycobacterial infection. We established a good model to study host defense mechanism against mycobacteria through α-defensin via eosinophils.

DOI： 10.1292/jvms.18-0619

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Nature Publishing Group  

The architecture of the genome influences the functions of DNA from bacteria to eukaryotes. Intrinsically disordered regions (IDR) of eukaryotic histones have pivotal roles in various processes of gene expression. IDR is rare in bacteria, but interestingly, mycobacteria produce a unique histone-like protein, MDP1 that contains a long C-terminal IDR. Here we analyzed the role of IDR in MDP1 function. By employing Mycobacterium smegmatis that inducibly expresses MDP1 or its IDR-deficient mutant, we observed that MDP1 induces IDR-dependent DNA compaction. MDP1-IDR is also responsible for the induction of growth arrest and tolerance to isoniazid, a front line tuberculosis drug that kills growing but not growth-retardated mycobacteria. We demonstrated that MDP1-deficiency and conditional knock out of MDP1 cause spreading of the M. smegmatis genome in the stationary phase. This study thus demonstrates for the first time a C-terminal region-dependent organization of the genome architecture by MDP1, implying the significance of IDR in the function of bacterial histone-like protein.

DOI： 10.1038/s41598-018-26463-9

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Publishing type：Research paper (scientific journal)   Publisher：American Society for Microbiology  

Interleukin 21 (IL-21) is a pleiotropic common cytokine receptor γ chain cytokine that promotes the effector functions of NK cells and CD8
⁺
T cells and inhibits CD8
⁺
T cell exhaustion during chronic infection. We found that the absolute number of short-lived effector CD8
⁺
T cells (SLECs) (KLRG1
^high
CD127
^low
) decreased significantly in IL-21 receptor-deficient (IL-21R
^−/−
) mice during
<named-content content-type="genus-species">Mycobacterium bovis</named-content>
bacillus Calmette-Guérin (BCG) infection.

DOI： 10.1128/IAI.00147-18

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© 2018, Springer-Verlag GmbH Austria, part of Springer Nature. Mycobacteriophage archival stocks have been kept for ca. 20–50 years in Japan. In this study, we attempted to recover mycobacteriophages from 50 archival stocks and briefly analyzed the recovered phages. The phages were recovered from 72.2% (13/18) of the lyophilized stocks that had been stored for 47-56 years. Moreover, the analysis of 12 representative recovered phages led to their classification as belonging to the family Siphoviridae, and seven of them were typed by polymerase chain reaction (PCR) targeting the gene that encodes the tape measure protein. Considering these results, lyophilization seems to be suitable for phage archival storage.

DOI： 10.1007/s00705-018-3788-8

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© 2018 Uchiyama et al. Using Mycobacterium smegmatis mc2155, 12 siphoviruses were recovered from long-term archival stocks stored in Japan. Their genome sequences were 46.0 to 61.3 kbp with 63 to 68% G+C contents, which allowed them to be categorized within cluster W and subclusters A1, A2, B3, A7, I1, and K4.

DOI： 10.1128/genomeA.00472-18

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Association for Dental Sciences of the Republic of China  

Background/purpose Few studies have investigated the possibility that bisphosphonate-related osteonecrosis of the jaw (BRONJ) might reflect an immune response
however, gamma delta T cells have been shown to significantly decline in the blood of BRONJ patients. Additionally, there have been some reports of teriparatide usage for the treatment of BRONJ. In this study, we compared the effects of zoledronate and teriparatide on lymphocyte populations and inflammatory cytokine production in mice. Materials and methods Thirty female ICR mice were divided into three groups (n = 10 each): a vehicle, a zoledronate, and a teriparatide group. Drugs were administered for 8 weeks in each group. Lymphocytes in the blood and thymus were analyzed and femurs were used for histological observation and lymphocytes analysis of bone marrow. Cytokines were measured in separated serum using Milliplex® multiplex immunoassay analysis. Results Zoledronate decreased the T cell number in the bone marrow. Additionally, serum levels of interleukin (IL)-2, IL-7, IL-12, IL-15 and RANTES, which are cytokines that affect T cell activation, differentiation and/or proliferation, were significantly lower in zoledronate treated mice. Conversely, teriparatide treatment induced an increase in gamma delta T cells in peripheral blood. Conclusion Gamma delta T cells in the bone marrow are expected to decrease with zoledronate treatment and increase with teriparatide treatment. If BRONJ involves a loss of gamma delta T cells in the circulation or bone marrow, then the increase in gamma delta T cells that is induced by teriparatide may account for its ability to resolve BRONJ.

DOI： 10.1016/j.jds.2017.03.007

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Language：English   Publisher：Elsevier Ltd  

Porphyromonas gingivalis (P. gingivalis) is a major oral pathogen and associated with periodontal diseases including periodontitis and alveolar bone loss. In this review, we indicate that two virulence factors, which are hemoglobin receptor protein (HbR) and cysteine proteases “gingipains”, expressed by P. gingivalis have novel functions on the pathogenicity of P. gingivalis. P. gingivalis produces three types of gingipains and concomitantly several adhesin domains. Among the adhesin domains, hemoglobin receptor protein (HbR), also called HGP15, has the function of induction of interleukin-8 (IL-8) expression in human gingival epithelial cells, indicating the possibility that HbR is associated with P. gingivalis-induced periodontal inflammation. On bacteria-host cells contact, P. gingivalis induces cellular signaling alteration in host cells. Phosphatidylinositol 3-kinase (PI3K) and Akt are well known to play a pivotal role in various cellular physiological functions including cell survival and glucose metabolism in mammalian cells. Recently, we demonstrated that gingipains attenuate the activity of PI3K and Akt, which might have a causal influence on periodontal diseases by chronic infection to the host cells from the speculation of molecular analysis. In this review, we discuss new molecular and biological characterization of the virulence factors from P. gingivalis.

DOI： 10.1016/j.jdsr.2017.06.001

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Language：English   Publisher：Japanese Association for Oral Biology  

Background Porphyromonas gingivalis is s major oral bacterium closely associated with periodontal diseases including periodontitis and directly affects host cellular signaling. The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway plays multiple roles in various cell functions including cell survival and glucose metabolism. In this review, we describe the effect of gingipains on the PI3K/Akt signaling pathway in P. gingivalis infection. Highlight Gingipains inactivate PI3K and Akt in gingival epithelial cells infected with P. gingivalis. These events occur independently of invasion of this organism into the cells and are required for the enzymatic activity of gingipains. Furthermore, 3-Phosphoinositide-dependent protein kinase-1 (PDK1) failed to translocate to the plasma membrane from the cytosol following PI3K inactivation. Additionally, dephosphorylation of Akt downstream proteins, including glycogen synthase kinase 3 (GSK3), mammalian target of rapamycin (mTOR), and Bad, occurs in parallel with the dysregulation of PI3K/PDK1/Akt cascades. Conclusion This review describes the biological characterization of gingipains, which inactivate PI3K and Akt, and disorder the PI3K/Akt signaling pathway. Hence, gingipains may decrease cellular physiological functions, eventually disrupting the gingival epithelium and causing development of periodontal diseases.

DOI： 10.1016/j.job.2017.05.003

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SAGE PUBLICATIONS LTD  

Innate T cells expressing V6 produce IL-17A at an early stage following infection with Mycobacterium bovis Bacillus Calmette-Guerin (BCG). In this study, we used IL-21 receptor knockout (IL-21R KO) mice and IL-21-producing recombinant BCG mice (rBCG-Ag85B-IL-21) to examine the role of IL-21 in the regulation of IL-17A-producing innate T-cell response following BCG infection. IL-17A-producing V6(+) T cells increased in the peritoneal cavity of IL-21R KO mice more than in wild type mice after BCG infection. In contrast, the number of IL-17A-producing V6(+) T cells was significantly lower after inoculation with rBCG-Ag85B-IL-21 compared with control rBCG-Ag85B. Notably, exogenous IL-21 selectively induced apoptosis of IL-17A-producing V6(+) T cells via Bim. Thus, these results suggest that IL-21 acts as a potent inhibitor of a IL-17A-producing T-cell subset during BCG infection.

DOI： 10.1177/1753425916664125

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Mycobacterium bovis Bacillus Calmette-Guerin (BCG) is used for the treatment of bladder cancer. The recruitment of neutrophlis to the bladder after BCG instillation exerts anti-tumor activity against bladder tumor. We have recently demonstrated that interleukin (IL)-17A produced by gamma delta T cells played a role in the recruitment of neutrophlis to the bladder after BCG instillation. IL-15 is known to play an important role in neutrophil migration during inflammation. We previously constructed a recombinant BCG strain expressing the fusion protein of IL-15 and Ag85B (BCG-IL-15) for prevention of Mycobacterium tuberculosis infection. Here we compared the efficacy of the BCG-IL-15 in protection against bladder cancer with that of rBCG-Ag85B (BCG).
Six-week-old female C57BL/6 mice were inoculated with MB49 bladder tumor cells in the bladder and subsequently intravesically inoculated with BCG or BCG-IL-15.
BCG-IL-15 treatment significantly prolonged survival of mice inoculated with bladder cancer cells compared with BCG treatment. Infiltration of neutrophils was significantly elevated in BCGB-IL-15 treated mice accompanied by increased chemokines (MIP-2 and MIP-1 alpha) in the bladder. Thus, BCG-IL-15 exerted additive effect on Infiltration of neutrophils in the bladder. BCG-IL-15 may be a promising drug for non-muscle invasive bladder cancer. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.intimp.2016.03.007

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Interleukin 7 (IL-7) has an important function in the development and maintenance of IL-17A+ gamma delta T cells. We here constructed a recombinant Mycobacterium bovis bacillus Calmette-Guerin expressing antigen 85B (Ag85B)-IL-7 fusion protein (rBCG-Ag85B-IL-7). The Ag85B-IL-7 fusion protein and IL-7 were detected in the bacterial lysate of rBCG-Ag85B-IL-7. rBCG-Ag85B-IL-7 was the same in number as control rBCG expressing Ag85B (rBCG-Ag85B) in the lung at the early stage after intravenous inoculation, whereas the numbers of IL-17A+ gamma delta T cells and Ag-specific Th1 cells were significantly higher in the lungs of mice inoculated with rBCG-Ag85B-IL-7 than those inoculated with rBCG-Ag85B. The Ag-specific Thl cell response was impaired in mice lacking IL-17A+ gamma delta T cells after inoculation with rBCG-Ag85B-IL-7. Thus, rBCG-Ag85B-IL-7 increases the pool size of IL-17A+ gamma delta T cells, which subsequently augment the Thl response to mycobacterial infection. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vaccine.2016.03.096

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

The oral Gram-negative anaerobic bacterium Porphyromonas gingivalis is an important pathogen involved in chronic periodontitis. Among its virulence factors, the major extracellular proteinases, Arg-gingipain and Lys-gingipain, are of interest given their abilities to degrade host proteins and process other virulence factors. Gingipains possess C-terminal domains (CTDs) and are translocated to the cell surface or into the extracellular milieu by the type IX secretion system (T9SS). Gingipains contribute to the colonial pigmentation of the bacterium on blood agar. In this study, Omp17, the PGN_0300 gene product, was found in the outer membrane fraction. A mutant lacking Omp17 did not show pigmentation on blood agar and showed reduced proteolytic activity of the gingipains. CTD-containing proteins were released from bacterial cells without cleavage of the CTDs in the omp17 mutant. Although synthesis of the anionic polysaccharide (A-LPS) was not affected in the omp17 mutant, the processing of and A-LPS modification of CTD-containing proteins was defective. PorU, a C-terminal signal peptidase that cleaves the CTDs of other CTD-containing proteins, was not detected in any membrane fraction of the omp17 mutant, suggesting that the defective maturation of CTD-containing proteins by impairment of Omp17 is partly due to loss of function of PorU. In the mouse subcutaneous infection experiment, the omp17 mutant was less virulent than the wild type. These results suggested that Omp17 is involved in P. gingivalis virulence.

DOI： 10.1128/IAI.01308-15

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

BCG, only vaccine available to prevent tuberculosis, was established in the early 20th century by prolonged passaging of a virulent clinical strain of Mycobacterium bovis. BCG Tokyo-172, originally distributed within Japan in 1924, is one of the currently used reference substrains for the vaccine. Recently, this substrain was reported to contain two spontaneously arising, heterogeneous subpopulations (Types I and II). The proportions of the subpopulations changed over time in both distributed seed lots and commercial lots. To maintain the homogeneity of live vaccines, such variations and subpopulational mutations in lots should be restrained and monitored. We incorporated deep sequencing techniques to validate such heterogeneity in lots of the BCG Tokyo-172 substrain without cloning. By bioinformatics analysis, we not only detected the two subpopulations but also detected two intrinsic variations within these populations. The intrinsic variants could be isolated from respective lots as colonies cultured on plate media, suggesting analyses incorporating deep sequencing techniques are powerful, valid tools to detect mutations in live bacterial vaccine lots. Our data showed that spontaneous mutations in BCG vaccines could be easily monitored by deep sequencing without direct isolation of variants, revealing the complex heterogeneity of BCG Tokyo-172 and its daughter lots currently in use.

DOI： 10.1038/srep17827

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

Mycobacterium smegmatis has been widely used as a mycobacterial infection model. Unlike the M. smegmatis mc(2)155 strain, M. smegmatis J15cs strain has the advantage of surviving for one week in murine macrophages. In our previous report, we clarified that the J15cs strain has deleted apolar glycopeptidolipids (GPLs) in the cell wall, which may affect its morphology and survival in host cells. In this study, the gene causing the GPL deletion in the J15cs strain was identified. The mps1-2 gene (MSMEG_0400-0402) correlated with GPL biosynthesis. The J15cs strain had 18 bps deleted in the mps1 gene compared to that of the mc2155 strain. The mps1-complemented J15cs mutant restored the expression of GPLs. Although the J15cs strain produces a rough and dry colony, the colony morphology of this mps1-complement was smooth like the mc2155 strain. The length in the mps1-complemented J15cs mutant was shortened by the expression of GPLs. In addition, the GPL-restored J15cs mutant did not survive as long as the parent J15cs strain in the murine macrophage cell line J774.1 cells. The results are direct evidence that the deletion of GPLs in the J15cs strain affects bacterial size, morphology, and survival in host cells.

DOI： 10.1371/journal.pone.0126813

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Porphyromonas gingivalis is a major pathogen of periodontal diseases, including periodontitis. We have investigated the effect of P. gingivalis infection on the PI3K/Akt (protein kinase B) signaling pathway in gingival epithelial cells. Here, we found that live P. gingivalis, but not heat-killed P. gingivalis, reduced Akt phosphorylation at both Thr-308 and Ser-473, which implies a decrease in Akt activity. Actually, PI3K, which is upstream of Akt, was also inactivated by P. gingivalis. Furthermore, glycogen synthase kinase 3 alpha/beta, mammalian target of rapamycin, and Bad, which are downstream proteins in the PI3K/Akt cascade, were also dephosphorylated, a phenomenon consistent with Akt inactivation by P. gingivalis. However, these events did not require direct interaction between bacteria and host cells and were independent of P. gingivalis invasion into the cells. The use of gingipain-specific inhibitors and a gingipain-deficient P. gingivalis mutant KDP136 revealed that the gingipains and their protease activities were essential for the inactivation of PI3K and Akt. The associations between the PI3K regulatory subunit p85 alpha and membrane proteins were disrupted by wild-type P. gingivalis. Moreover, PDK1 translocation to the plasma membrane was reduced by wild-type P. gingivalis, but not KDP136, indicating little production of phosphatidylinositol 3,4,5-triphosphate by PI3K. Therefore, it is likely that PI3K failed to transmit homeostatic extracellular stimuli to intracellular signaling pathways by gingipains. Taken together, our findings indicate that P. gingivalis attenuates the PI3K/Akt signaling pathway via the proteolytic effects of gingipains, resulting in the dysregulation of PI3K/Akt-dependent cellular functions and the destruction of epithelial barriers.

DOI： 10.1074/jbc.M114.591610

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BIOMED CENTRAL LTD  

Background: Porphyromonas gingivalis has been implicated as a major pathogen in the development and progression of chronic periodontitis. P. gingivalis biofilm formation in the subgingival crevice plays an important role in the ability of the bacteria to tolerate stress signals outside the cytoplasmic membrane. Some bacteria use a distinct subfamily of sigma factors to regulate their extracytoplasmic functions (the ECF subfamily). The objective of this study was to determine if P. gingivalis ECF sigma factors affect P. gingivalis biofilm formation.
Methods: To elucidate the role of ECF sigma factors in P. gingivalis, chromosomal mutants carrying a disruption of each ECF sigma factor-encoding gene were constructed. Bacterial growth curves were measured by determining the turbidity of bacterial cultures. The quantity of biofilm growing on plates was evaluated by crystal violet staining.
Results: Comparison of the growth curves of wild-type P. gingivalis strain 33277 and the ECF mutants indicated that the growth rate of the mutants was slightly lower than that of the wild-type strain. The PGN_0274- and PGN_1740-defective mutants had increased biofilm formation compared with the wild-type (p &lt; 0.001); however, the other ECF sigma factor mutants or the complemented strains did not enhance biofilm formation.
Conclusion: These results suggest that PGN_0274 and PGN_1740 play a key role in biofilm formation by P. gingivalis.

DOI： 10.1186/1472-6831-15-4

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：EDIZIONI INT SRL  

The periodontal pathogen, Porphyromonas gingivalis ATCC 33277 has six gene clusters that encode tripartite drug efflux pumps. To examine the effects of the drug efflux pumps on its antibiotic sensitivity, six mutants were constructed, each defective in the membrane fusion protein gene of each gene cluster. Compared to the wild-type strain, all mutants exhibited an elevated sensitivity to tetracycline, and two mutants with deletions in the PGN_1431 and PGN_1680 genes showed an increased sensitivity to various types of antibiotics. These results suggest that the activity of drug efflux systems may affect antibiotic sensitivity in P. gingivalis.

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We report here the construction of a plasmid vector designed for the efficient electrotransformation of the periodontal pathogen Porphyromonas gingivalis. The novel Escherichia coli-Bacteroides/P. gingivalis shuttle vector, designated pTIO-1, is based on the 11.0-kb E. coli-Bacteroides conjugative shuttle vector, pVAL-1 (a pB8-51 derivative). To construct pTIO-1, the pB8-51 origin of replication and erythromycin resistance determinant of pVAL-1 were cloned into the E. coli cloning vector pBluescript II SK(-) and non-functional regions were deleted. pTIO-1 has an almost complete multiple cloning site from pBluescript II SK(-). The size of pTIO-1 is 4.5 kb, which is convenient for routine gene manipulation. pTIO-1 was introduced into P. gingivalis via electroporation, and erythromycin-resistant transformants carrying pTIO-1 were obtained. We characterized the transformation efficiency, copy number, host range, stability, and insert size capacity of pTIO-1. An efficient plasmid electrotransformation of P. gingivalis will facilitate functional analysis and expression of P. gingivalis genes, including the virulence factors of this bacterium. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.mimet.2014.07.032

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

Periodontitis is an inflammatory disease of polymicrobial origin affecting the tissues supporting the tooth. The oral anaerobic bacterium Porphyromonas gingivalis, which is implicated as an important pathogen for chronic periodontitis, triggers a series of host inflammatory responses that promote the destruction of periodontal tissues. Among the virulence factors of P. gingivalis, hemoglobin receptor protein (HbR) is a major protein found in culture supernatants. In this study, we investigated the roles of HbR in the production of inflammatory mediators. We found that HbR induced interleukin-8 (IL-8) production in the human gingival epithelial cell line Ca9-22. p38 mitogen-activated protein kinase (MAPK) and extracellular signal-related kinase 1/2 (Erk1/2) were activated in HbR-stimulated Ca9-22 cells. Inhibitors of p38 MAPK (SB203580) and Erk1/2 (PD98059) blocked HbR-induced IL-8 production. Additionally, HbR stimulated the translocation of NF-kappa B-p65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-kappa B pathway. In addition, small interfering RNA (siRNA) targeting activating transcription factor 2 (ATF-2) or cyclic AMP-response element-binding protein (CREB) inhibited HbR-induced IL-8 production. Moreover, pretreatment with SB203580 and PD98059 reduced HbR-induced phosphorylation of CREB and ATF-2, respectively. Combined pretreatment with an inhibitor of NF-kappa B (BAY11-7082) and SB203580 was more efficient in inhibiting the ability of HbR to induce IL-8 production than pretreatment with either BAY11-7082 or SB203580 alone. Thus, in Ca9-22 cells, the direct activation of p38 MAPK and Erk1/2 by HbR caused the activation of the transcription factors ATF-2, CREB, and NF-kappa B, thus resulting in the induction of IL-8 production.

DOI： 10.1128/IAI.01140-12

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Silkworm larva has recently been recognized as an alternative model animal for higher mammals to evaluate the effects of antibiotics. In this study, we examined the efficacy of the bacteriophage (phage) therapy, which harnesses phages as antibacterial agents, against Staphylococcus aureus infections, using the silkworm larval infection model. Two newly isolated staphylococcal phages, S25-3 and S13′, were used as therapeutic phage candidates. They were assigned to two different lytic phage genera, Twort-like and AHJD-like viruses, based on their morphologies and the N-terminal amino acid sequences of the major capsid proteins. Both had a broad host range and strong lytic activity and showed preservative quality. Administration of these phages alone caused no adverse effects in the silkworm larvae. Moreover, the viruses showed life-prolonging effects in the silkworm larval infection model 10 min, 6 h, 12 h, and 24 h following infection. Such phage effects in the silkworm larval model were almost paralleled to the therapeutic efficacies in mouse models. These results suggest that phages S25-3 and S13′ are eligible as therapeutic candidates and that the silkworm larval model is valid for the evaluation of phage therapy as well as mouse models. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

DOI： 10.1111/1574-6968.12220

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Development of accurate methods for predicting progression of tuberculosis (TB) from the latent state is recognized as vitally important in controlling TB, because a majority of cases develop from latent infections. Past TB that has never been treated has a higher risk of progressing than does latent Mycobacterium tuberculosis infection in patients who have previously received treatment. Antibody responses against 23 kinds of M. tuberculosis proteins in individuals with past TB who had not been medicated were evaluated. These individuals had significantly higher concentrations of antibodies against Antigen 85A and mycobacterial DNA-binding protein 1 (MDP1) than did those with active TB and uninfected controls. In addition, immunohistochemistry revealed colocalization of tubercle bacilli, antigen 85 and MDP1 inside tuberculous granuloma lesions in an asymptomatic subject, showing that M. tuberculosis in lesions expresses both antigen 85 and MDP1. Our study suggests the potential usefulness of measuring antibody responses to antigen 85A and MDP1 for assessing the risk of TB progression.

DOI： 10.1111/j.1348-0421.2012.12005.x

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATL INST INFECTIOUS DISEASES  

Pseudomonas aeruginosa is known to produce surfactants that are involved in its swarming motility behavior, such as rhamnolipids and their precursors-3-(3-hydroxyalkanoyloxy) alkanoic acids (HAAs). In P. aeruginosa PAO1, swarming motility is inhibited by some fatty acids, including branched-chain fatty acids and unsaturated fatty acids. In the present study, addition of 12-methyltetradecanoic acid (12-MTA, anteiso-C15:0) to an agar medium markedly repressed surfactant activity in the extracellular fraction of a P. aeruginosa culture in a drop collapse assay. Further, an extracellular fraction of a culture of rhlA mutant P. aeruginosa, which did not produce both rhamnolipids and HAAs, showed a complete loss of surfactant activity and markedly reduced swarming activity. In contrast, an extracellular fraction of a culture of rhlB mutant P. aeruginosa, which produced HAAs but not rhamnolipids, showed moderate swarming activity and weak extracellular surfactant activity that was lost on the addition of 12-MTA to the agar medium. Expression of the rhlAB operon from the plasmid pMR2 restored normal swarming motility on 12-MTA-containing agar medium. Taken together, these findings indicate that 12-MTA reduced extracellular surfactant activity, thus resulting in a swarming defect in P. aeruginosa PAO1.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Bacillus Calmette-Guerin (BCG) Tokyo 172 is a predominant World Health Organization Reference Reagent for the BCG vaccine. Recently, the BCG Tokyo 172 substrain was reported to consist of two subpopulations with different colony morphologies, smooth and rough. Smooth colonies had a characteristic 22-bp deletion in Rv3405c of the region of difference (RD) 16 (type I), and rough colonies were complete in this region (type II). We hypothesized that the morphological difference is related to lipid phenotype and affects their antigenicity. We determined the lipid compositions and biosynthesis of types I and II. Scanning electron microscopy showed that type I was 1.5 times longer than type II. Phenolic glycolipid (PGL) and phthiocerol dimycocerosate (PDIM) were found only in type I. Although it has been reported that the RD16 is involved in the expression of PGL, type II did not possess PGL/PDIM. We examined the ppsA-E gene responsible for PGL/PDIM biosynthesis and found that the existence of PGL/PDIM in types I and II is caused by a ppsA gene mutation not regulated by the RD16. PGL suppressed the host recognition of total lipids via Toll-like receptor 2, and this suggests that PGL is antigenic and involved in host responses, acting as a cell wall component. This is the first report to show the difference between lipid phenotypes of types I and II. It is important to clarify the heterogeneity of BCG vaccine substrains to discuss and evaluate the quality, safety, and efficacy of the BCG vaccine.

DOI： 10.1074/jbc.M111.310037

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

The oral anaerobic bacterium Porphyromonas gingivalis, which is implicated as an important pathogen for chronic periodontitis, requires heme for its growth. Non-iron metalloporphyrins, In-PPIX and Ga-PPIX, were examined for antibacterial effects on P. gingivalis. Both In-PPIX and Ga-PPIX caused retardation of P. gingivalis growth in a dose-dependent fashion. Microarray and qPCR analyses revealed that In-PPIX treatment upregulated the expression of several genes encoding proteins including ClpB and ClpC, which are members of the Clp (caseinolytic protease, Hsp100) family, and aRNR, aRNR-activating protein and thioredoxin reductase, whereas In-PPIX treatment had no effect on the expression of genes encoding proteins involved in heme uptake pathways, Hmu-mediated, Iht-mediated and Tlr-mediated pathways. P. gingivalis ihtA and ihtB mutants were more resistant to In-PPIX than was the wild-type parent, whereas hmuR and tlr mutants did not show such resistance to In-PPIX. The results suggest that In-PPIX is incorporated by the Iht-mediated heme uptake pathway and that it influences protein quality control and nucleotide metabolism and retards growth of P. gingivalis.

DOI： 10.1111/j.1348-0421.2010.00299.x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC MICROBIOLOGY  

Porphyromonas gingivalis is one of the most etiologically important microorganisms in periodontal disease. We found in a previous study that PG1385 (TprA) protein, a tetratricopeptide repeat (TPR) protein, was upregulated in P. gingivalis wild-type cells placed in a mouse subcutaneous chamber and that a tprA mutant was clearly less virulent in the mouse subcutaneous abscess model (M. Yoshimura et al., Oral Microbiol. Immunol. 23: 413-418, 2008). In the present study, we investigated the gene expression profile of tprA mutant cells placed in a mouse subcutaneous chamber and found that 9 genes, including PG2102 (tapA), PG2101 (tapB), and PG2100 (tapC) genes, were downregulated in the tprA mutant compared with those in the wild type. Expression of a cluster of tapA, tapB, and tapC genes of the mutant was also downregulated in an in vitro culture with enriched brain heart infusion medium. The TprA protein has three TPR motifs known as a protein-protein interaction module. Yeast two-hybrid system analysis and in vitro protein binding assays with immunoprecipitation and surface plasmon resonance detection revealed that the TprA protein could bind to TapA and TapB proteins. TprA and TapB proteins were located in the periplasmic space, whereas TapA, which appeared to be one of the C-terminal domain family proteins, was located at the outer membrane. We constructed tapA, tapB, and tapC single mutants and a tapA-tapB-tapC deletion mutant. In the mouse subcutaneous infection experiment, all of the mutants were less virulent than the wild type. These results suggest that TprA, TapA, TapB, and TapC are cooperatively involved in P. gingivalis virulence.

DOI： 10.1128/IAI.01448-09

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

Although the importance of T(h)1-type immune response in protection against mycobacterial infection is well recognized, its regulatory mechanism in the Mycobacterium tuberculosis (Mtb)-infected lung is not well characterized. To address this issue, we analyzed kinetics of induction of mycobacterial antigen-specific CD4(+) T(h)1 T cells after mycobacterial infection in P25 TCR-transgenic (Tg) mice which express TCR alpha and beta chains from a mycobacterial Ag85B-specific MHC class II A(b)-restricted CD4(+) T-cell clone. To supply normal regulatory T-cell repertoire, we transferred normal spleen T cells into the P25 TCR-Tg mice before infection. High dose subcutaneous infection with Mtb or Mycobacterium bovis bacillus Calmette-Guerin (BCG) induced P25 TCR-Tg CD4(+) T(h)1 cells within a week. In contrast, high-dose Mtb or BCG infection into the lung failed to induce P25 TCR-Tg CD4(+) T(h)1 cells at the early stage of the infection. Furthermore, low-dose Mtb infection into the lung induced P25 TCR-Tg CD4(+) T(h)1 cells on day 21 in the mediastinal lymph node but not in the lung. IL-10 was partially involved in the suppression of T(h)1 induction in the lung because pretreatment of mice with anti-IL-10 antibody resulted in increase of P25 TCR-Tg CD4(+) T(h)1 cells in the Mtb-infected lung on day 21 of the infection, whereas neutralization of transforming growth factor-beta, another important suppressive cytokine in the lung, showed no effects on the T(h)1 induction. Our data suggest that induction of anti-mycobacterial CD4(+) T(h)1 cells is suppressed in the mycobacteria-infected lung partially by IL-10.

DOI： 10.1093/intimm/dxq010

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Language：Japanese   Publisher：(一社)日本環境感染学会  

ATP測定法を用いて、歯科医師が着用している歯科用ゴーグルと眼鏡の清浄度調査を実施した。歯科診療の環境で歯科用ゴーグルのレンズ部表面は、診療開始前は平均11RLU(Relative Light Unit)であったが、診療1時間後には平均11638RLUに増加していた(t検定:p<0.05)。これは比較対象とした勉強会1時間後の平均値46RLUよりも、有意に清浄度が悪化していた(p<0.05)。また、眼鏡のレンズ部裏面は、診療開始前は平均7RLUであったが、診療1時間後には平均306RLUに増加していた。これは、歯科用ゴーグルの同部分より57RLUも有意に清浄度が悪化していた(p<0.05)。歯科医師が眼部の感染予防対策としては、眼鏡は防護具としては完璧なものではなく、歯科用ゴーグルを着用することが望ましい。また、ATP測定法による清浄度調査は簡便で迅速であるため、歯科診療における感染予防対策に有効活用できると考える。(著者抄録)

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2010&ichushi_jid=J05141&link_issn=&doc_id=20100412420003&doc_link_id=10.4058%2Fjsei.25.79&url=https%3A%2F%2Fdoi.org%2F10.4058%2Fjsei.25.79&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_3.gif

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Contamination of dental surgical goggles and protective spectacles was investigated using a measuring method to detect adenosine triphosphate (ATP). Mean concentration was 11 RLU (Relative Light Unit) at the beginning of the working day, but had increased to 11,638 RLU after 1 hour (t test: p&lt
0.05). Mean concentration on the lecture measured for comparison was 46 RLU (p&lt
0.05). Moreover, contamination of the back of the lens section of protective spectacles was 7 RLU at the beginning of the working day, but had increased to 306 RLU after 1 hour. The cleanliness factor was nearly worse than the back of the lens of dental surgical goggles (p&lt
0.05). Choice of optic protection against transmission of infection should consider that spectacles do not offer complete protection, so dentists should wear dental surgical goggles to perform dentistry examinations. Contamination investigation using a measuring method which evaluates ATP is both simple and quick, so can be used effectively as an index of environmental contamination in a dental clinic. © 2010, Japanese Society for Infection Prevention and Control. All rights reserved.

DOI： 10.4058/jsei.25.79

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ACAD PERIODONTOLOGY  

Background: Hydrogen sulfide is one of the predominant volatile sulfur compounds (VSCs) produced by oral bacteria. This study developed and evaluated a system for detecting hydrogen sulfide production by oral bacteria.
Methods: L-methionine-alpha-deamino-gamma-mercaptomethane-lyase (METase) and beta carbon-sulfur (beta C-S) lyase were used to degrade homocysteine and cysteine, respectively, to produce hydrogen sulfide. Enzymatic reactions resulting in hydrogen sulfide production were assayed by reaction with bismuth trichloride, which forms a black precipitate when mixed with hydrogen sulfide. The enzymatic activities of various oral bacteria that result in hydrogen sulfide production and the capacity of bacteria from periodontal sites to form hydrogen sulfide in reaction mixtures containing L-cysteine or DL-homocysteine were assayed.
Results: With L-cysteine as the substrate, Streptococcus anginosus FW73 produced the most hydrogen sulfide, whereas Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 and W83 and Fusobacterium nucleatum ATCC 10953 produced similar to 35% of the amount produced by the P. gingivalis strains. Finally, the hydrogen sulfide found in subgingival plaque was analyzed. Using bismuth trichloride, the hydrogen sulfide produced by oral bacteria was visually detectable as a black precipitate.
Conclusions: Hydrogen sulfide production by oral bacteria was easily analyzed using bismuth trichloride. However, further innovation is required for practical use. J Periodontol 2009, 80:1845-1851.

DOI： 10.1902/jop.2009.090012

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL PUBLISHING, INC  

Introduction:
Porphyromonas gingivalis is implicated as a major pathogen in the development and progression of chronic periodontitis. P. gingivalis must possess the ability to tolerate stress signals outside the cytoplasmic membrane by transcriptional activation of genes encoding proteins involved in defense or repair processes. Some bacteria utilize a distinct subfamily of sigma factors to regulate extracytoplasmic function (hence termed the ECF subfamily).
Methods:
To elucidate their role in P. gingivalis, a chromosomal mutant carrying a disruption of an ECF sigma factor PG1318-encoding gene was constructed. Hemagglutination and proteolytic activities were measured in the PG1318-defective mutant. Reverse transcription-polymerase chain reaction (RT-PCR) analysis and southern blot analysis were used to assess transcription of kgp in the PG1318-defective mutant. Frequency of spontaneous mutation that conferred resistance to l-trifluoromethionine was measured in the PG1318-defective mutant.
Results:
The PG1318-defective mutant formed non-pigmented colonies on blood agar plates at a relatively high frequency. Arginine-specific and lysine-specific proteinase activities of the non-pigmented variants were remarkably decreased compared with those of the parent strain and the pigmented variants. RT-PCR analysis showed that kgp was not transcribed in some non-pigmented variants and southern blot analysis revealed that there was a deletion in their kgp region. Frequency of mutation conferring resistance to l-trifluoromethionine was significantly higher in the PG1318-defective mutant than in the wild-type.
Conclusion:
These results suggest that PG1318 plays a role in the regulation of mutation frequency in the bacterium.

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Introduction: Porphyromonas gingivalis, an oral anaerobic bacterium, is considered a major pathogen for chronic periodontitis. Pathogenic bacteria usually upregulate or downregulate gene expression to combat the protective responses of their hosts.
Methods: To determine what protein is regulated when P. gingivalis cells invade host tissues, we analyzed the proteome of P. gingivalis cells that were placed in a mouse subcutaneous chamber by two-dimensional gel electrophoresis and mass spectrometry.
Results: Fourteen proteins were upregulated, while four proteins were downregulated. We focused on three upregulated proteins, PG1089 (DNA-binding response regulator RprY), PG1385 (TPR domain protein), and PG2102 (immunoreactive 61-kDa antigen), and constructed mutant strains that were defective in these proteins. Mouse abscess model experiments revealed that the mutant strain defective in PG1385 was clearly less virulent than the wild-type parent strain.
Conclusion: These results indicate that the PG1385 protein is involved in P. gingivalis virulence and that the method used here is useful when investigating the P. gingivalis proteins responsible for virulence.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

The gram-negative anaerobic bacterium Porphyromonas gingivalis is a major causative agent of chronic periodontitis. Porphyromonas gingivalis strains have been classified into virulent and less-virulent strains by mouse subcutaneous soft tissue abscess model analysis. Here, we present the whole genome sequence of P gingivalis ATCC 33277, which is classified as a less-virulent strain. We identified 2090 protein-coding sequences (CDSs), 4 RNA operons, and 53 tRNA genes in the ATCC 3 3 2 7 7 genome. By genomic comparison with the virulent strain W83, we identified 461 ATCC 33277-specific and 415 W83-specific CDSs. Extensive genomic rearrangements were observed between the two strains: 175 regions in which genomic rearrangements have occurred were identified. Thirty-five of those genomic rearrangements were inversion or translocation and 140 were simple insertion, deletion, or replacement. Both strains contained large numbers of mobile elements, such as insertion sequences, miniature inverted-repeat transposable elements (MITEs), and conjugative transposons, which are frequently associated with genomic rearrangements. These findings indicate that the mobile genetic elements have been deeply involved in the extensive genome rearrangement of P gingivalis and the occurrence of many of the strain-specific CDSs. We also describe here a very unique feature of MITE400, which we renamed MITEPgRS (MITE of P gingivalis with Repeating Sequences).

DOI： 10.1093/dnares/dsn013

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：UNIV CHICAGO PRESS  

Protection against Mycobacterium tuberculosis not only depends on CD4(+) T helper type 1 (Th1) cells but, also, on CD8(+) T cells. Interleukin (IL)-15 has an important function in the maintenance of memory CD8(+) T cells. In the present study, we examined the efficacy of recombinant Mycobacterium bovis bacille Calmette-Guerin (rBCG) secreting fusion protein antigen (Ag) 85B murine IL-15 (rBCG-Ag85B-IL15) in providing protection against M. tuberculosis infection. The levels of major histocompatibility (MHC) class Ib (H2-M3)-binding TB2- or MHC class Ia (H-2D(b))-binding MPT64-specific CD8(+) T cells producing interferon (IFN)-gamma were significantly higher after immunization with rBCG-Ag85B-IL15 than after immunization with rBCG secreting Ag85B (rBCG-Ag85B). The levels of purified protein derivative-or Ag85B-specific CD4(+) Tcells producing IFN-gamma were also higher in mice immunized with rBCG-Ag85B-IL15 than in mice immunized with rBCG-Ag85B. Mice immunized with rBCG-Ag85B-IL15 exhibited CD8(+) and CD+ T cells responses that were stronger than those in mice immunized with rBCG-Ag85B, as well as robust protection in the lung against intratracheal challenge of M. tuberculosis. Thus, rBCG-Ag85B-IL15 vaccination capable of inducing efficient cell-mediated immunity might be used as an effective vaccine for tuberculosis.

DOI： 10.1086/586902

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL PUBLISHING  

Background and Objective: Chronic periodontitis is an inflammatory disease caused by bacteria in subgingival pockets. Because Toll-like receptor 2 and Toll-like receptor 4 have been shown to play an important role in the recognition of periodontal pathogens, we investigated the relevance of genetic variations in TLR2 and TLR4 to susceptibility to periodontitis.
Material and Methods: A total of 97 patients with chronic periodontitis and 100 control subjects were examined for mutations in TLR2 and TLR4. Case-control analysis was performed using individual single nucleotide polymorphisms detected during the mutation search.
Results: The missense mutations reported previously in TLR2 (677 Arg &gt; Trp and 753 Arg &gt; Gln) and in TLR4 (299 Asp &gt; Gly and 399 Thr &gt; Ile) were not detected in 97 of the Japanese patients with chronic periodontitis or in 100 of the Japanese control subjects. Nine single nucleotide polymorphisms were identified in exons of TLR2 and TLR4. The case-control analysis revealed that the frequency of the C/C genotype at base-pair position +3725 in TLR4 was significantly higher in both the moderate and the severe periodontitis patient group than in the control group.
Conclusion: A genetic variation of TLR4 might be associated with moderate and severe periodontitis in the Japanese population.

DOI： 10.1111/j.1600-0765.2007.00979.x

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Focusing on the final step of osteoclastogenesis, we studied cell fusion from tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells into multinuclear cells. TRAP-positive mononuclear cells before generation of multinuclear cells by cell fusion were differentiated from RAW264.7 cells by treatment with receptor activator of nuclear factor kappa B ligand (RANKL), and then the cells were treated with lipopolysaccharide (LPS), followed by culturing for further 12 h. LPS-induced cell fusion even in the absence of RANKL. Similarly, tumor necrosis factor (TNF)-alpha and peptidoglycan (PGN) induced cell fusion, but M-CSF did not. The cell fusion induced by RANKL, TNF-alpha, and LPS was specifically blocked by osteoprotegerin (OPG), anti-TNF-alpha antibody, and polymyxin B, respectively. LPS- and PGN-induced cell fusion was partly inhibited by anti-TNF-alpha antibody but not by OPG. When TRAP-positive mononuclear cells fused to yield multinuclear cells, phosphorylation of Akt, Src, extracellular signal-regulated kinase (ERK), p38MAPK (p38), and c-Jun NH2-terminal kinase (JNK) was observed. The specific chemical inhibitors LY294002 (PI3K), PP2 (Src), U0126 (MAPK-ERK kinase (MEK)/ERK), and SP600125 (JNK) effectively suppressed cell fusion, although SB203580 (p38) did not. mRNA of nuclear factor of activated T-cells c1 (NFATc1) and dendritic cell-specific transmembrane protein (DC-STAMP) during the cell fusion was quantified, however, there was no obvious difference among the TRAP-positive mononuclear cells treated with or without M-CSF, RANKL, TNF-alpha, LPS, or PGN. Collectively, RANKL, TNF-alpha, LPS, and PGN induced cell fusion of osteoclasts through their own receptors. Subsequent activation of signaling pathways involving PI3K, Src, ERK, and JNK molecules was required for the cell fusion. Although DC-STAMP is considered to be a requisite for cell fusion of osteoclasts, cell fusion-inducing factors other than DC-STAMP might be necessary for the cell fusion.

DOI： 10.1002/jcb.21167

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Extracellular proteinaceous factors of Porphyromonas gingivalis, a periodontal pathogen, that influence receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL)-induced osteoclastogenesis from bone marrow macrophages were investigated. The culture supernatant of P. gingivalis had the ability to inhibit RANKL-induced in vitro osteoclastogenesis. A major protein of the culture supernatant, hemoglobin receptor protein (HbR), suppressed RANKL-induced osteoclastogenesis in a dose-dependent fashion. HbR markedly inhibited RANKL-induced osteoclastogenesis when present in the culture for the first 24 h after addition of RANKL, whereas no significant inhibition was observed when HbR was added after 24 h or later, implying that HbR might interfere with only the initial stage of RANKL-mediated differentiation. HbR tightly bound to bone marrow macrophages and had the ability to induce phosphorylation of ERK, p38, NF-kappaB, and Akt. RANKL-induced phosphorylation of ERK, p38, and NF-kappaB was not suppressed by HbR, but that of Akt was markedly suppressed. HbR inhibited RANKL-mediated induction of c-Fos and NFATc1. HbR could induce beta interferon (IFN-beta) from bone marrow macrophages, but the induction level of IFN-beta might not be sufficient to suppress RANKL-mediated osteoclastogenesis, implying presence of an IFN-beta-independent pathway in HbR-mediated inhibition of osteoclastogenesis. Since rapid and extensive destruction of the alveolar bone causes tooth loss, resulting in loss of the gingival crevice that is an anatomical niche for periodontal pathogens such as P. gingivalis, the suppressive effect of HbR on osteoclastogenesis may help the microorganism exist long in the niche.

DOI： 10.1128/IAI.74.5.2544-2551.2006

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GENERAL MICROBIOLOGY  

Inspection of the genomic DNA sequence of the oral anaerobe Porphyromonas gingivalis reveals that the micro-organism possesses the peroxide-sensing transcription activator OxyR, but not the superoxide-sensing transcription factor SoxR. Investigatation of oxiclative-stress-responsive proteins in P. gingivalis by two-dimensional gel electrophoresis showed that two proteins were predominantly upregulated in oxidative conditions. In a P. gingivalis oxyR mutant these two proteins were not induced by treatment with hydrogen peroxide under aerobic conditions. By N-terminal amino acid sequencing, the two proteins were found to be superoxide dismutase and alkyl hydroperoxide reductase, encoded by sod and ahpC, respectively. Northern blot and lacZ fusion analyses revealed that P. gingivalis sod and ahpC were positively regulated by OxyR. Primer extension analysis located the promoter regions of sod and ahpC, and putative -35 boxes of these promoters were found immediately adjacent to their putative OxyR-binding sequences. Moreover, the promoter regions of sod and ahpC had the ability to bind P. gingivalis OxyR protein. These results demonstrate that P. gingivalis sod is one of the OxyR regulons, suggesting that OxyR functions as an intracellular redox sensor rather than a peroxide sensor in this organism. A sod gene of Bacteroides fragilis, which is taxonomically related to P. gingivalis, is inducible by redox stresses but not controlled by its OxyR. A DNA fragment including the B. fragilis sod promoter region could bind the P. gingivalis OxyR protein; however, a putative OxyR binding sequence within the DNA fragment was 14 bases distant from a putative -35 box of its promoter.

DOI： 10.1099/mic.0.28537-0

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On single nasal immunization of mice with killed-bacillus calmette-guerin (BCG) plus a mutant Escherichia coli enterotoxin, delayed-type hypersensitivity was induced and BCG-infection decreased. Spleen cells, particularly CD4(+) T cells among them produced IL-2, IFN gamma and TNF alpha in response to the killed-BCG or purified protein derivatives. CD8(+) T cells including cytotoxic T lymphocytes produced IFN gamma and TNF alpha. However, both types of T cells reacted a little to Ag85B.
The mutant induces cellular immunity to nasal killed-BCG vaccine and decreases BCG-infection. CD4(+) and CD8(+) T cells produce cytokines effective for tuberculosis. Although killed-BCG loses some antigens like Ag85B, nasal killed-BCG plus the mutant is useful for tuberculosis. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vaccine.2006.01.060

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In anaphase, microtubules provide a specification signal for positioning of the contractile ring. However, the nature of the signal remains unknown. The small GTPase Rho is a potent regulator of cytokinesis, but the involvement of Rho in contractile ring formation is disputed. Here, we show that Rho serves as a microtubule-dependent signal that specifies the position of the contractile ring. We found that Rho translocates to the equatorial region before furrow ingression. The Rho-specific inhibitor C3 exoenzyme and small interfering RNA to the Rho GDP/GTP exchange factor ECT2 prevent this translocation and disrupt contractile ring formation, indicating that active Rho is required for contractile ring formation. ECT2 forms a complex with the GTPase-activating protein MgcRacGAP and the kinesinlike protein MKLP1 at the central spindle, and the localization of ECT2 at the central spindle depends on MgcRacGAP and MKLP1. In addition, we show that the bundled microtubules direct Rho-mediated signaling molecules to the furrowing site and regulate furrow formation. Our study provides strong evidence for the requirement of Rho-mediated signaling in contractile ring formation.

DOI： 10.1091/mbc.e05-06-0569

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Evidence from recent epidemiological studies suggests a link between periodontal infections and increased risk of atherosclerosis and related cardiovascular and cerebrovascular events in human subjects. One of the major pathogens of periodontitis, Porphyromonas gingivalis, has the ability to aggregate human platelets in platelet-rich plasma (PRP). Mechanism of P. gingivalis-induced platelet aggregation in PRP was investigated. Proteinase inhibitors toward Arg-gingipain (Rgp) and Lys-gingipain (Kgp) did not suppress P. gingivalis-induced platelet aggregation in PRP, whereas the Rgp inhibitor markedly inhibited P. gingivalis-induced platelet aggregation using washed platelets. Mutant analysis revealed that P. gingivalis-induced platelet aggregation in PRP depended on Rgp-, Kgp- and haemagglutinin A (HagA)-encoding genes that intragenically coded for adhesins such as Hgp44. Hgp44 adhesin on the bacterial cell surface, which was processed by Rgp and Kgp proteinases, was essential for P. gingivalis-induced platelet aggregation in PRP. P. gingivalis cell-reactive IgG in plasma, and Fc gamma RIIa receptor and to a lesser extent GPIb alpha receptor on platelets were found to be a prerequisite for P. gingivalis-induced platelet aggregation in PRP. These results reveal a novel mechanism of platelet aggregation by P. gingivalis.

DOI： 10.1111/j.1365-2958.2005.04942.x

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Although amphotericin B (AmB) is a major polyene antibiotic against invasive fungal infection, administration to patients sometimes causes inflammatory side effects, which limits the usage of the antibiotic. We studied the intracellular signaling that was induced by AmB. p65 (RelA) of nuclear factor-kappaB (NF-kappaB), a well-known signaling molecule as an inducer of proinflammatory cytokines, was phosphorylated by AmB in RAW264.7 cells, a monocyte-like cell line. Among chemical inhibitors of signaling molecules, U-73122 (phospholipase C (PLC) inhibitor), Gö6976 (protein kinase C (PKC) inhibitor), BAPTA-AM (calcium chelator), LFM-A13 (Bruton's tyrosine kinase (Btk)-specific inhibitor), and PP2 (c-Src kinase inhibitor) suppressed AmB-induced phosphorylation of p65 and translocation of p65 into the nucleus. U-73122 and Gö6976 reduced AmB-mediated induction of proinflammatory cytokines (tumor necrosis factor (TNF)-alpha and interleukin (IL)-6) in RAW264.7 cells. Furthermore, AmB-induced activation of NF-kappaB was observed in toll-like receptor (TLR) 2-expressed cells, and the activation of NF-kappaB was inhibited by U-73122, whereas peptidoglycan-induced NF-kappaB activation, which was also dependent on TLR2, was not inhibited by U-73122. Finally, U-73122 partially suppressed in vivo production of TNF-alpha and IL-6 induced by AmB administration in BALB/c mice. These results suggested that the signaling from AmB stimulation to proinflammatory cytokine production is mediated by TLR2, Btk, PLC, PKC, c-Src and NF-kappaB. These signaling molecules may become a target for chemotherapy suppressing AmB-induced proinflammatory cytokine production.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

The dual membrane envelopes of Gram-negative bacteria provide two barriers of unlike nature that regulate the transport of molecules into and out of organisms. Organisms have developed several systems for transport across the inner and outer membranes. The Gram-negative periodontopathogenic bacterium Porphyromonas gingivalis produces proteinase and adhesin complexes, gingipains/adhesins, on the cell surface and in the extracellular milieu as one of the major virulence factors. Gingipains and/or adhesins are encoded by kgp, rgpA, rgpB, and hagA on the chromosome. In this study, we isolated a P. gingivalis mutant (porT), which showed very weak activities of gingipains in the cell lysates and culture supernatants. Subcellular fractionation and immunoblot analysis demonstrated that precursor forms of gingipains and adhesins were accumulated in the periplasmic space of the porT mutant cells. Peptide mass fingerprinting and N-terminal amino acid sequencing of the precursor proteins and the kgp'-'rgpB chimera gene product in the porT mutant indicated that these proteins lacked the signal peptide regions, consistent with their accumulation in the periplasm. The PorT protein seemed to be membrane-associated and exposed to the periplasmic space, as revealed by subcellular fractionation and immunoblot analysis using anti-PorT antiserum. These results suggest that the membrane-associated protein PorT is essential for transport of the kgp, rgpA, rgpB, and hagA gene products across the outer membrane from the periplasm to the cell surface, where they are processed and matured.

DOI： 10.1074/jbc.M413544200

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GENERAL MICROBIOLOGY  

Porphyromonas gingivalis, an obligately anaerobic bacterium, is implicated as a major pathogen in the development and progression of chronic periodontitis. Although expression of several virulence factors of the bacterium has been found to be affected by environmental stress such as entrance into the stationary growth phase and heat, there is relatively little information on the mechanisms that may operate in the bacterium in response to environmental stress. In this study, a novel protein (UstA) was investigated that was initially identified following two-dimensional gel analysis. Expression of UstA was upregulated in stationary phase or by exposure to atmospheric oxygen. N-terminal sequencing and database analysis with the P. gingivalis genome sequence revealed that the UstA-encoding gene (ustA) was located upstream of a homologue of the usp gene encoding the universal stress protein on the chromosome. The ustA gene appeared to be transcribed in a monocistronic fashion, as revealed by primer extension and Northern blot analysis. To elucidate the role of UstA in the bacterium, chromosomal mutants carrying a disruption of the ustA gene were constructed. The ustA mutant grew slower than the wild-type parent strain in rich medium, resulting in a lower yield in stationary phase. Furthermore, in this mutant, expression levels of the P. gingivalis homologues of superoxide dismutase, thiol peroxidase and thioredoxin were markedly higher than those in the wild-type, especially in stationary phase. The ustA mutant was more resistant to diamide, a thiol-specific oxidant, than the wild-type. In addition, the ustA mutation suppressed hypersensitivities of the oxyR mutant to diamide, metronidazole and mitomycin C. These results suggest that UstA may play a significant role in oxidative stress responses in the bacterium.

DOI： 10.1099/mic.0.27589-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We have developed two novel tuberculosis (TB) vaccines: a DNA vaccine combination expressing mycobacterial heat shock protein 65 (Hsp65) and interleukin-12 (IL-12) by using the hemagglutinating virus of Japan (HVJ)-liposome (HSP65 + IL-12/HVJ) and a recombinant BCG harboring the 72f fusion gene (72f rBCG). These vaccines provide remarkable protective efficacy in mouse and guinea pig models, as compared to the current by available BCG vaccine. In the present study, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis, to evaluate the HSP65 + IL-12/HVJ and 72f rBCG vaccines. Vaccination with HSP65 + IL-12/HVJ as well as 72f rBCG vaccines provided better protective efficacy as assessed by the Erythrocyte Sedimentation Rate, chest X-ray findings and immune responses than BCG. Most importantly, HSP65 + IL-12/HVJ resulted in an increased survival for over a year. This is the first report of successful DNA vaccination and recombinant BCG vaccination against M. tuberculosis in the monkey model. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vaccine.2005.01.057

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Bacterial cell surface filaments play significant roles in adherence to and invasion of host cells. They are generated by the chaperone/usher pathway system (class I fimbriae), the type II secretion system (type IV pili) and the nucleation-dependent polymerization system (Curli filaments) that are categorized by their modes of expression and assembly. In this study, we found that the periodontal pathogen Porphyromonas gingivalis expressed the major structural components of two cell surface filaments (fimbrilin and the 75 kDa protein) that had extremely long prosequences in their primary gene products. N-terminal amino acid sequencing of the prosequences, treatment of P. gingivalis cells with globomycin, an inhibitor for lipoprotein-specific signal peptidase, amino acid substitution of the cysteine residue of the prosequence of fimbrilin and [H-3]-palmitic acid labelling implied that fimbrilin and the 75 kDa protein were matured through their lipoprotein precursor forms. Accumulation of precursor forms of fimbrilin and the 75 kDa protein on the cell surface of the gingipain-null mutant revealed that Arg-gingipain processed these precursors on the surface to yield their mature forms, which subsequently assembled into the filamentous structures, suggesting that the transport and assembly of the major component proteins appear to be novel.

DOI： 10.1111/j.1365-2958.2004.04105.x

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Bacterial infection sometimes impairs bone metabolism. In this study, we infected the osteoblastic cell line MC3T3-E1 with Mycobacterium bovis bacillus Calmette-Guérin (BCG) and identified genes that were up-regulated in the BCG-infected cells by the suppression subtractive hybridization method. A gene encoding 4-1BB (CD137), a member of the tumor necrosis factor-alpha receptor family, was found to be one of the up-regulated genes. Up-regulation of 4-1BB was also observed by infection with Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus, and by treatment with lipopolysaccharides and heat-killed BCG. Bone marrow cells and the macrophage-like cell lines J774 and RAW264.7 were found to express 4-1BB ligand (4-1BBL). Recombinant 4-1BB (r4-1BB) that was immobilized on culture plates strongly inhibited macrophage colony stimulating factor (M-CSF)/receptor activator of nuclear factor-kappaB ligand (RANKL)-induced in vitro osteoclast formation from bone marrow cells. Anti-4-1BBL antibody also inhibited osteoclast formation to a lesser extent, indicating involvement of reverse signaling through 4-1BBL during inhibition of osteoclast formation. A casein kinase I (CKI) inhibitor markedly suppressed the inhibitory effect of r4-1BB on M-CSF/RANKL-induced osteoclast formation, suggesting that CKI might be involved in 4-1BB/4-1BBL reverse signaling. r4-1BB showed no effects on M-CSF- or RANKL-induced phosphorylation of I-kappaB, ERK1/2, p38, or JNK, whereas RANKL-induced phosphorylation of Akt, a downstream target of phosphatidylinositol 3-kinase (PI3K), was completely abolished by r4-1BB, suggesting that 4-1BB/4-1BBL reverse signaling may interfere with PI3K/Akt pathway. r4-1BB also abolished RANKL-mediated induction of nuclear factor of activated T cells-2. This study may elucidate a novel role of 4-1BB in cell metabolism, especially osteoclastogenesis.

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We report here the induction of specific protective cellular immunity against Mycobacterium tuberculosis by the employment of vaccination with recombinant attenuated Listeria monocytogenes strains. We constructed self-destructing attenuated L. monocytogenes Delta2 strains carrying eukaryotic expression plasmids for the antigen 85 complex (Ag85A and Ag85B) and for MPB/MPT51 (mycobacterial protein secreted by M. bovis BCG/mycobacterial protein secreted by M. tuberculosis) molecules. Infection of these recombinant bacteria allowed expression of the genes in the J774A.1 murine macrophage cell line. Intraperitoneal vaccination of C57BL/6 mice with these recombinant bacteria,was capable of inducing purified protein derivative-specific cellular immune responses, such as foot pad reactions, proliferative responses of splenocytes, and gamma interferon production from splenocytes, suggesting the efficacy of vaccination against mycobacterial infection by use of these recombinant L. monocytogenes strains. Furthermore, intravenous vaccination with recombinant bacteria carrying expression plasmids for Ag85A, Ag85B, or MPB/MPT51 in BALB/c mice elicited significant protective responses, comparable to those evoked by a live Mycobacterium bovis BCG vaccine. Notably, this is the first report to show that MPB/MPT51 is a major protective antigen in addition to Ag85A and Ag85B, which have been reported to be major mycobacterial protective antigens.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

The human ECT2 protooncogene encodes a guanine nucleotide exchange factor for the Rho GTPases and regulates cytokinesis. Although the oncogenic form of ECT2 contains an N-terminal truncation, it is not clear how the structural abnormality of ECT2 causes malignant transformation. Here we show that both the removal of the negative regulatory domain and alteration of subcellular localization are required to induce the oncogenic activity of ECT2. The transforming activity of oncogenic ECT2 was strongly inhibited by dominant negative Rho GTPases, suggesting the involvement of Rho GTPases in ECT2 transformation. Although deletion of the N-terminal cell cycle regulator-related domain (N) of ECT2 did not activate its transforming activity, removal of the small central domain (S), which contains two nuclear localization signals (NLSs), significantly induced the activity. The ECT2 N domain interacted with the catalytic domain and significantly inhibited the focus formation by oncogenic ECT2. Interestingly, the introduction of the NLS mutations in the S domain of N-terminally truncated ECT2 dramatically induced the transforming activity of this otherwise nononcogenic derivative. Among the known Rho GTPases expressed in NIH 3T3 cells, RhoA was predominantly activated by oncogenic ECT2 in vivo. Therefore, the mislocalization of structurally altered ECT2 might cause the untimely activation of cytoplasmic Rho GTPases leading to the malignant transformation.

DOI： 10.1074/jbc.M306725200

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Although Rho GTPases regulate multiple cellular events, their role in cell division is still obscure. Here we show that expression of a GTPase-activating protein (GAP)-deficient mutant (R386A) of the Rho regulator MgcRacGAP induces abnormal cortical activity during cytokinesis in U20S cells. Multiple large blebs were observed in cells expressing MgcRacGAP R386A from the onset of anaphase to the late stage of cell division. When mitotic blebbing was excessive, cytokinesis was inhibited, and cells with micronuclei were generated. It has been reported that blebbing is caused by abnormal cortical activity. The MgcRacGAP R386A-induced abnormal cortical activity was inhibited by the dominant negative form of RhoA, but not Rac1 or Cdc42. Moreover, expression of constitutively active RhoA also induced drastic cortical activity during cytokinesis. Unlike apoptotic blebbing, MgcRacGAP R386A-induced blebbing was not inhibited by the ROCK inhibitor Y-27632, suggesting that MgcRacGAP regulates cortical activity during cytokinesis through a novel signaling pathway. We propose that MgcRacGAP plays a pivotal role in cytokinesis by regulating cortical movement through RhoA. (C) 2003 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.yexcr.2003.10.015

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：MEDIMOND PUBLISHING CO  

HVJ-liposome / HSP65 DNA + IL-12 DNA vaccination were 100 fold more efficient than BCG on the elimination of Mycobacterium tuberculosis (M,TB) in lungs, liver, and spleen in he BALB/c mice. Cytotoxic T cells activity against M.TB in the mice was augmented. The recombinant(r) 72f BCG vaccine as well as HSP65 DNA + IL-12 DNA vaccine showed stronger anti-TB immunity than BCG in the mice, and guinea pigs. By using these new vaccines (HSP65 DNA + IL-12 DNA, r72f BCG and 72f fusion protein + BCG) and the cynomolgus monkey models which are very similar to human tuberculosis, the prophylactic effect (survival, Erythrocyte Sedimentation Rate, chest X-P finding, immune responses) of vaccines was observed. Thus, these novel vaccines should provide a useful tool for the prevention of human TB infection.

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Coincubation of monocytoid cell line U937 cells cotransfected with HIV-1 LTR CAT plasmid and Tat expression plasmid, with Mycobacterium smegmatis, M. avium, M. bovis BCG and M. tuberculosis enhanced chloramphenicol acetyltransferase (CAT) production, indicating that these mycobacteria could activate the LTR in this cell line. The amount of CAT in the cells coincubated with M. smegmatis was higher than that infected with the other mycobacteria after 12, 24 and 48 hour time periods. However, the amount of CAT production in the cells cocultured with M. tuberculosis was higher than those coincubated with the other mycobacteria at 72 hours. These findings indicated that avirulent mycobacteria such as M. smegmatis may activate HIV replication at an early time and its effects are gradually decreased, while the effect of virulent M. tuberculosis increased gradually, and lasted for a long time resulting in an acceleration of HIV disease in patients.

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Language：English   Publisher：NATL INST INFECTIOUS DISEASES  

DNA containing an unmethylated CpG motif has a potent immunostimulatory effect on the vertebrate immune system. Because such CpG motifs are relatively common in bacterial DNA, but rare in mammalian animal and plant DNA, they may be an evolutionary adaptation augmenting innate immunity, most likely in response to pathogens that replicate within the host cells, such as viruses and intracellular bacteria. Microbial infection induces innate immunity by triggering pattern-recognition systems. The infected cells produce proinflammatory cytokines that directly combat microbial invaders and express costimulating surface molecules, which develop adaptive immunity by inducing distinct T cell differentiation. Bacterial DNA with unmethylated CpG-DNA stimulates vertebrate immature immune cells to induce maturation and to produce TNF-alpha as well as Th1-type cytokines, IL-12 and IFN-gamma. Therefore, CpG-DNA functions as an adjuvant for regulating the initiation of Th1 differentiation. The roles of immunostimulatory CpG motifs in DNA vaccine developments and in therapeutic applications have been discussed.

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Matrix vesicles (MV) having high alkaline phosphatase (ALP) activity act as initiators of biological mineralization. Although bacteria have similar membranous structures to MV. ALP mediated mineralization has not been studied in bacterial cells. Escherichia coli was transformed with a bacterial ALP gene in this study. Recombinant E. coli overproducing ALP induced mineralization through hydrolysis of calcium-glycerophosphate (Ca-GP). Fourier transform infrared spectroscopy and electron microscopy combined with electron diffraction revealed newly formed hydroxyapatite mineral deposits. These findings suggest that hydrolysis of Ca-GP through ALP induced high Ca and Pi concentrations within bacterial cells followed by complete bacterial mineralization.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Mycobacterial infection occurs commonly in patients with acquired immune deficiency syndrome. Incubation of monocytoid cell line U937 cells, which was cotransfected HIV-1 long terminal repeat sequence (LTR) chloramphenicol acetyltransferase (CAT) plasmid and Tat expression plasmid, with mycobacterium smegmatis, Mycobacterium avium, Mycobacterium bovis BCG and Mycobacterium tuberculosis resulted in enhancement of CAT production, indicating that these mycobacteria could activate LTR in this cell line. The amount of CAT in the cells coexisting with M. smegmatis was higher than that infected with other mycobacteria. The amounts of CAT production in the cells coculturing with M. avium and M. bovis BCG were intermediate. M. tuberculosis slightly stimulated CAT production. The amount of tumor necrosis factor (TNF)-alpha produced by transfected U937 cells was correlated with the amount of CAT production. The interleukin (IL)-1 beta and IL-6 levels in the supernatant from coculturing with all species were similar. The antibody to TNF-alpha inhibited CAT production induced by mycobacterial infections. The anti-IL-1 beta and anti-IL-6 antibodies, however, scarcely influenced stimulation of LTR by mycobacteria. In addition, U937 cells transfected with full length LTR CAT plasmid showed increased CAT production by activation with mycobacteria, but the cells transfected with mutant LTR CAT constructs from which the nuclear factor (NF)-KB binding site was deleted did not show activation. These findings indicated that activation of Mycobacterium-induced LTR CAT is NF-KB dependent. These findings suggested that activation of HIV-1 LTR by mycobacteria was mainly mediated by NF-KB-induced secondary release of cytokine TNF-alpha. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science BN. All rights reserved.

DOI： 10.1111/j.1574-695X.2001.tb00505.x

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Authorship：Lead author,　Corresponding author   Language：English   Publisher：ELSEVIER SCI LTD  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MUNKSGAARD INT PUBL LTD  

Mycobacterial infection is a common occurrence in patients with acquired immune deficiency syndrome. Incubation of U1, a chronically HIV-1-infected human promonocytic cell line, with Mycobacterium smegmatis, M. avium, M. bovis BCG and M. tuberculosis resulted in enhancement of p24 antigen release in the supernatant, indicating that these mycobacteria could activate HIV replication from this cell line. The amount of p24 in the culture infected with M. smegmatis was higher than in cultures infected with other mycobacteria. The amounts of p24 release in cultures infected with M. avium and M. bovis BCG were intermediate. M. tuberculosis slightly stimulated HIV replication. The amount of TNF-alpha produced by U1 cells was correlated with the amount of p24 antigen release. The IL-1 beta and IL-6 levels in the supernatant from cultures infected with all species were the same. The antibody to TNF-alpha inhibited p24 release induced by mycobacterial infections. The anti-IL-1 beta and anti-IL-6 antibodies, however, scarcely influenced stimulation of HIV replication by mycobacterial infection. These data suggested that activation of HIV replication by mycobacteria mainly occurred by secondary release of cytokine TNF-alpha.

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The components of Ag85 (Ag85A, Ag85B, and Ag85C) are putative protective antigen candidates against mycobacterial infection. A recombinant Mycobacterium boris Bacillus Calmette-Guerin (rBCG) over-producing Ag85A, Ag85B, and MPB51 (rBCG/BA51) was constructed. rBCG/BA51 could secrete these antigens at levels more than five times higher than parental BCG. Immunization of C57BL/6 and BALB/c mice with this rBCG reduced the multiplication of Mycobacterium leprae in the foot pads of both strains of mice. The inhibition by rBCG/BA51 was more evident than that by parental BCG. (C) 2001 Elsevier Science Ltd. All rights reserved.

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HrpA was found as a ribosome-associated protein which appeared in heat-stressed Mycobacterium bovis Bacillus Calmette-Guerin. Here, we have studied the function of HrpA in vitro. HrpA is a heat shock protein belonging to a small heat shock protein family. The putative molecular mass was 17784.86 kDa. Recombinant HrpA formed large complexes of nonamer or dodecamer. HrpA prevented the aggregation of enzymes under heat shock conditions, and it formed stable complexes with partially denatured enzymes. HrpA was induced temporarily by oxygen repletion after anaerobic condition. (C) 2000 Academic Press.

DOI： 10.1006/mpat.2000.0384

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MUNKSGAARD INT PUBL LTD  

Mycobacterium avium is an intracellular pathogen and a major opportunistic infectious agent observed in patients with acquired immune deficiency syndrome (AIDS). Fibronectin is an extracellular matrix protein and is a virulence factor for several extracellular pathogenic bacteria binding to mucosal surfaces. We investigated the fibronectin (FN)-binding proteins in the culture filtrate of nl. avium by two-dimensional electrophoresis (2DE). Proteins in Sauton medium of nl. nl avium after 3 weeks were separated by 2DE. The proteins were blotted onto polyvinylidene difluoride membrane and incubated with FN. FN-binding proteins were detected by Western blotting using anti-FN antibody FN bound to five spots (33 kDa, 32 kDa, 31 kDa, 30 kDa and 25 kDa). N-terminal amino acids of these were determined. The 33 kDa spot corresponded to antigen 85 (Ag 85) C. The 31 and 31 kDa spots were either Ag 85 A or Ag 85 B. The 30 kDa spot corresponded to Ag 85 B of nl. avium. The 25 kDa spot corresponded to MPA51 (M. avium MPB51). Thus, FN bound exclusively to the Ag 85 complex and MPA51.

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Immunization of mice with recombinant Mycobacterium bovis Bacillus Calmette-Guerin (rBCG) which over-produces a putative protective antigen candidate, the A component of antigen 85 complex (Ag85A), reduced the multiplication of Mycobacterium leprae in the foot pads of mice. The inhibition by this rBCG (rBCG/85A) was more evident than that with parental BCG. Repeated rBCG/85A immunization significantly could reduce M. leplae multiplication in mice. This is first report of rBCG to control mycobacterial infection in animal model. Therefore, rBCG technique may be useful for the development of a more effective mycobacteria vaccine. (C) 2000 Elsevier Science Ltd. All rights reserved.

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The proteins in culture filtrate derived from Bacillus Calmette-Guerin (BCG) were examined for protection against infection by Mycobacterium leprae. Immunization with the major secreted proteins, antigen 85 complex (Ag 85) A: B and C, induced effective protective immunity against multiplication of M. leprae in the foot pads of mice. The most effective protection was observed when mice were immunized with Ag 85A. A single immunization with Ag 85 could induce antigen-specific interferon gamma (IFN gamma) synthesis and more effective protection than live BCG vaccine. This study demonstrates that Ag 85 is an important immunoprotective molecule against leprosy infection. (C) 1999 Elsevier Science Ltd. All rights reserved.

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The alpha antigen, which is an immunodominant antigen, is a 30 kDa protein secreted by mycobacterial species. The C-terminal regions of alpha antigens are quite divergent. We investigated the question of whether the C-tenninal regions of Mycobacterium avium alpha antigen (A-alpha), M. intracellulare alpha antigen (I-alpha) and M. bovis BCG alpha antigen (B-alpha) contained species-specific B-cell epitopes. We investigated the reactions of these peptides with anti-A-alpha, anti-I-alpha and anti-B-alpha sera prepared from BALB/c in a Western blot assay and ELISA. The C-terminal regions of I-alpha reacted exclusively with anti-I-alpha serum. The results of the inhibition assay of antibodies binding to I-alpha by peptides of C-A-alpha, C-I-alpha, and C-B-alpha are that only C-I-alpha inhibited the binding of antibodies to C-I-alpha. We found that the C-terminal region was B-cell epitope-specific to I-alpha in BALB/c mice. (C) 1999 Elsevier Science B.V. All rights reserved.

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The ribosomes from BCG strongly induced delayed type hypersensitivity (DTH) skin reactions in guinea pigs immunized with live BCG or heat killed Mycobacterium tuberculosis H37Rv, and also induced lymphocyte proliferative response in mice immunized with ribosomes. In contrast, neither ribosomal proteins nor RNA alone induced both DTH skin reactions and lymphocyte proliferative responses. Particle form consisted of ribosomal proteins and RNAs might be absolutely required for the activation of immune responses. (C) 1998 Elsevier Science Ltd. All rights reserved.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：MUNKSGAARD INT PUBL LTD  

The alpha antigen, which is a 30 kDa protein secreted by mycobacterial species, is an immunodominant antigen. The C-terminal regions of alpha antigens are highly divergent, though there are regions where the amino acid sequence of a antigen is conserved. We investigated whether the C-terminal regions of the Mycobacterium avium alpha antigen, M. intracellular alpha antigen and M. tuberculosis alpha antigen contain sequence-specific B-cell epitopes. The C-terminal regions of M. avium alpha antigen and M. intracellulare alpha antigen reacted to anti-M. avium alpha antigen but not to anti-M. tuberculosis alpha antigen derived from rabbits. Thus, M. avium and M. intracellulare have an antigenic determinant in common with rabbit. The C-terminal region of M. tuberculosis alpha antigen did not react to anti-M. avium alpha antigen or anti-M. tuberculosis alpha antigen. An enzyme-linked immunosorbent assay revealed that only the C-terminal region of M. avium alpha antigen reacted to the sera of two of six patients with M. avium-intracellulare (MAC) but not to the sera of patients with M. tuberculosis. In contrast, the C-terminal regions of M. intracellulare alpha antigen and M. tuberculosis a antigen were not recognized by the sera from patients with MAC or M. tuberculosis. This region of M. avium alpha antigen can produce a sequence-specific B-cell epitope in humans.

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Mapping of B-cell epitopes on alpha antigen of Mycobacterium kansasii (K-alpha) was carried out by using recombinant truncated K-alpha fusion peptides. We observed that two immunodominant B-cell epitopes (amino acids 222-268 and 267-306) and one minor epitope (amino acid 249-286) were located in the C-terminal region of K-alpha. The other three minor B-cell epitopes were mapped in N-terminal (amino acids 80-98 and 99-166) and central (amino acid 174-203) regions of K-alpha. All defined epitopes were common to Mycobacterium tuberculosis and M. kansasii. Besides these common epitopes, a region in K-alpha (amino acid 290-319) revealed different reactivities between antibodies against K-alpha and alpha antigen of M. tuberculosis. These findings may provide a basis for development of serodiagnosis that can distinguish between M. kansasii and M. tuberculosis infections.

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A 16-kDa protein, identical to the a-crystallin-like stress protein, was induced under O-2-deficient culture conditions and bound principally to the 30S ribosomal subunits of Mycobacterium bovis BCG substrain Tokyo (BCG). The 16-kDa protein was shown to be tightly associated with the ribosome.

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We previously identified an IS200-like sequence (ISAa1) in the genome of Actinobacillus actinomycetemcomitans FDC Y4. One or more hybridizing bands to the ISAa1 probe were detected in each of several reference strains, representing three of the serotypes (a through c) of A. actinomycetemcomitans. In this study, we examined whether a restriction fragment-length polymorphism (RFLP) with ISAa1 as a probe could differentiate clinical isolates. One or more hybridizing bands were detected in each of the 27 strains examined, which could be divided into seven groups according to restriction fragment-length polymorphism pattern. Several strains were observed with identical restriction fragment-length polymorphism types but with different serotypes. Conversely, strains were also observed with differing restriction fragment-length polymorphism types and identical serotypes.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

The binding motifs of the immunodominant antigen (Ag) alpha-Ag (Ag 85 complex B) of Mycobacterium kansasii for human fibronectin were examined using digested fragments. We defined two fibronectin-binding epitopes on 27 amino acids from 84 to 110 and on 20 amino acids from 211 to 230, The epitopes were almost conserved in the closely related Ag 85 complex of other mycobacteria species. Inhibition of fibronectin binding to intact alpha-Ag molecules was observed with peptide-(84-110), but not with peptide-(211-230). Peptide (84-110) could also inhibit fibronectin binding to all components of the Ag 85 complex of Bacillus Calmette-Guerin (Ag 85A, Ag 85B, and Ag 85C). Further study with synthetic peptides defined 11 residues from 98 to 108 as the minimum motif. Six residues ((98)FEWYYQ(103)) were critical for interacting with fibronectin. The motif revealed no homology to other known prokaryotic and eukaryotic fibronectin-binding proteins. The defined motif of alpha-Ag is novel and unique for mycobacteria.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：LUIGI PONZIO E FIGLIO  

Mycobacterium bovis BCG (BCG) contains a low number of ribosomes compared to rapidly growing Escherichia coli.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CENTER ACADEMIC PUBL JAPAN  

The shotgun cloning of a Mycobacterium bovis BCG (BCG) genome into pBluescript SK (+) successfully yielded a 0.9 kbp fragment, confirming the ability of Escherichia coli thyA mutant MH2702 to grow in a thymine-depleted medium. This DNA fragment contained a gene homologous to the thymidylate synthase (TS)-encoding genes (thyA) of other organisms. An inverted repeat sequence and open reading frame (ORF) were observed at the upstream region of the thyA. A computer analysis revealed that the protein encoded by this ORF possessed a structure unique for a DNA binding protein.

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The component of mycobacterial 85 complex (85A, 85B, and 85C) and MPB51 are very important from immunological, biochemical, and antimycobacterial points of view. In this study, the transcriptional properties of genes encoding three components of 85 complex and MPB51 from BCG were analysed. The authors' analyses revealed that genes for 85A and MPB51 were transcribed as a single unit despite the one operon-like structure and these four genes were probably under a different regulatory control. These findings may help to understand the immunological and physiological roles of these antigens. (C) 1997 Academic Press Limited.

DOI： 10.1006/mpat.1997.0159

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A novel 18-kDa heat shock protein, HrpA, has been identified from Mycobacterium bovis BCG. HrpA was rapidly synthesized in membrane and ribosome fractions but not in the cytoplasmic fraction under heat shock stress. HrpA bound tightly to 70S ribosomes, mainly in 30S subunits. HrpA might be involved in the initiation step of translation at high temperature.

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The components of the fibronectin-binding antigen 85 complex (85A, 85B, and 85C) and the related protein MPB/MPT51 are major secreted proteins in Mycobacterium tuberculosis and Mycobacterium bovis BCT;, The fbpA, fbpC, and mpt51 genes encoding 85A, 85C, and MPT51, respectively, were isolated from Mycobacterium avium and sequenced in this study, The structures of these genes, and that of the fbpB gene encoding the 85B protein, were conserved in these three species. The secreted amounts of 85A, 85B, 85C, and MPB/MPT51 were compared for M. tuberculosis, BCG, and M, avium, These four proteins were found in large amounts in the culture filtrates from M. tuberculosis and BCG, In contrast, in the culture filtrate from M. avium, 85B and MPT51 were abundant whereas 85A and 85C were hardly found, in spite of the presence of the encoding genes, The difference in the secretion amounts might be regulated at the transcription level, These facts might reflect host immunopathogenesis, the protective immunities against infections, and the drug susceptibilities of these organisms.

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Transcriptional analysis of the groESL operon from Porphyromonas gingivalis, one of the obligative anaerobic oral microorganisms implicated in adult periodontitis, was performed. P. gingivalis 381 cultured at 37 degrees C was shifted to 42 degrees C, 45 degrees C or 48 degrees C for 10 mins. Northern hybridization analysis revealed that a band with 2.1-kb (kilo base pair) was observed, and the transcripts increased greatly by heat shock. Primer extension and S1 mapping detected four different 5'-ending sites of the mRNAs at the upstream region of the groES. Three sites out of the four were heat-inducible. There were inverted repeats and a Escherichia coli sigma 32-recognizing consensus sequence in the promoter region of the groESL, which may be relevant to the regulation of transcription of groESL operon in P. gingivalis. Both a heat shock promoter and inverted repeats may be relevant to the transcriptional regulation of the groESL operon in P. gingivalis.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Immunization of mice with the ribosomal fraction from ruptured Mycobacterium bovis Bacillus Calmette-Guerin (BCG) and the culture filtrate reduced remarkably the multiplication of Mycobacterium leprae in the foot pads of mice, This is the first reported case of the protective activity against M, leprae multiplication in mice of the BCG ribosomal fraction and culture filtrate. The inhibition was more evident with the culture filtrate than with the ribosomal fraction. When the ribosomal proteins separated from ribosomal RNA were injected into mice, only slight inhibition was observed Ribosomal RNA alone did not inhibit at all, in contrast to the conclusion reported by Youmans and Youmans. (C) 1997 Elsevier Science Ltd.

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In the amino acid (AA) sequences of alpha antigen from mycobacteria, C-terminal regions were variable among a variety of mycobacterial species though the N-terminal regions were relatively conserved. These regions may possess some species-specific antigenic determinants of the alpha antigen from Mycobacterium scrofulaceum (S-alpha). AAs288-300 of S-alpha fused to beta-galactosidase was reactive with the antisera raised against S-alpha. The same fused peptide did not react with the antisera raised against the alpha antigen from Mycobacterium avium (A-alpha) and Mycobacterium bovis BCG (B-alpha). B-cell epitope mapping then was performed focusing on the C-terminal region of S-alpha using the synthetic peptides. Their reactivities with antisera raised against the alpha antigens of three different mycobacterial species were assessed by ELISA. AAs279-286 were a cross-reactive common immunodominant region among three mycobacterial species. This region may be one of the crossreactive common epitopes in mycobacterial species. And AAs291-300 were reactive only with the antisera raised against S-alpha. This region may possess a species-specific epitope. (C) 1997 Academic Press Limited.

DOI： 10.1006/mpat.1997.0147

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We have cloned and sequenced the 5.2 kb EcoRI fragment that contained part of the S10 operon from Actinobacillus actinomycetemcomitans FDC Y4. The order of the ribosomal protein genes was identical to that of the S10 operon of Haemophilus influenzae and Escherichia coli. The deduced amino acid sequences of ribosomal proteins in this operon displayed significant homologies (65.3%-100%) to those of H. influenzae, E. coli, Yersinia enterocolitica and Yersinia pseudotuberculosis. Phylogenetic trees obtained for these ribosomal proteins were similar to that obtained for 16S rRNA.

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We have found a new insertion sequence (IS), designated ISAa1, downstream of the S10 operon in Actinobacillus (Haemophilus) actinomycetemcomitans FDC Y4. ISAa1, the first IS element characterized in this organism, is 705 bp long and lacks terminal inverted repeats. This element displayed significant homology with IS200. Hybridization patterns of genomic DNA of seven A. actinomycetemcomitans strains with an internal ISAa1 probe varied depending on the serotypes, suggesting that ISAa1 might be a useful tool for epidemiological studies.

DOI： 10.1099/00221287-142-9-2449

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Language：Japanese   Publisher：Japanese Leprosy Association  

BCG vaccine (Tokyo strain) was given in BALB/cA mice intradermally 1 or 3 months before Mycobacterium leprae (M. leprae) challenge as modified Shepard's method. The vaccine dosage was 7-8 or 106. The BCG gave good protection in both dosages and both challenges against M. leprae infection.<br>Lymphocytes proliferations of BCG-vaccinated splenocyte cultures in response to M. leprae lysate or BCG components (hsp65, 38kD, 30kD or 12kD protein) were tested, and potent proliferative responses were seen in the cultures with M. leprae lysate and hsp 65. Furthermore, γ-IFN productions were positive in the cultures with M. leprae lysate or hsp 65, but negative with other antigens. The production of γ-IFN with hsp 65 was never inhibited with polymyxin B, but inhibited with IL-10.<br>These results show that BCG (Tokyo strain) is a useful vaccine for M. leprae infection in mice, and one of the components of BCG, hsp 65, may be a effective antigen component for protection of M. leprae infection inducing Thl type cytokine.

DOI： 10.5025/hansen.65.106

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MPB70 is secreted in high concentrations by Mycobacterium bovis BCG substrain Tokyo (BCG Tokyo), but little by substrains Pasteur (BCG Pasteur) and M. tuberculosis. The gene encoding a MPB70 homologue secreted by BCG Tokyo was found at the upstream region of the gene encoding MPB70, with approximately 2.3 kilobase pairs (kbp) spacing: the same gene was also found in BCG Pasteur. This gene was cloned and sequenced from BCG Tokyo. The DNA sequence which contained a 663 base pair (bp) open reading frame beginning at position 1 and ending with a TAA codon at position 661 was found. Its theoretical molecular mass was calculated to be 22.068 kDa. This gene was highly homologous to the coding region of mpb70 and the deduced amino acid sequence was very similar to MPB83 reported by Harboe et al. It was speculated that the gene the authors characterized probably corresponded to the mpb83 gene.

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The recombinant bacillus Calmette-Guerin (rBCG) secretion system utilizing an extracellular alpha antigen of Mycobacterium kansasii (alpha-K) was characterized biochemically and immunologically. The human immunodeficiency virus type1 (HIV-1)p17(gag) B cell epitope fused to alpha-K was secreted in extremely large amounts. At least three mice out of seven inoculated with rBCG generated high titres of antibody to the epitope. The long-lasting antibody production persisted more than 14 months.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BUTTERWORTH-HEINEMANN LTD  

The live bacterial vaccine Mycobacterium bovis BCG (BCG) is a vehicle worth noticing for various protective antigens. The gene encoding the B-cell epitope of the oligopeptide repeating in the circumsporozoite protein (C.S. protein) of the rodent malaria parasite, Plasmodium yoelii, was inserted into the plasmid vector under the control of an expression cassette carrying the promoter and signal sequence of the a antigen derived from Mycobacterium kansasii (k-a). The B-cell epitope was successfully expressed and secreted from BCG as a fusion protein with k-a. This recombinant BCG was administered subcutaneously into BALB/c mice and the antibody production was measured by the enzyme-linked immunosorbent assay (ELISA). Long lasting humoral response was found in one of seven mice.

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BCG vaccine (Tokyo strain) was given in BALB/cA mice intradermally 1 or 3 months before Mycobacterium leprae (M. leprae) challenge as modified Shepard's method. The vaccine dosage was 107-8 or 106. The BCG gave good protection in both dosages and both challenges against M. leprae infection. Lymphocytes proliferations of BCG-vaccinated splenocyte cultures in response to M. leprae lysate or BCG components (hsp65, 38kD, 30kD or 12kD protein) were tested, and potent proliferative responses were seen in the cultures with M. leprae lysate and hsp65. Furthermore, γ-IFN productions were positive in the cultures with M. leprae lysate or hsp65, but negative with other antigens. The production of γ-IFN with hsp65 was never inhibited with polymyxin B, but inhibited with IL 10. These results show that BCG (Tokyo strain) is a useful vaccine for M. leprae infection in mice, and one of the compounds of BCG, hsp65, may be a effective antigen component for protection of M. leprae infection inducing Th1 type cytokine.

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Language：English   Publisher：LUIGI PONZIO E FIGLIO  

The internal control of DNA for the rapid detection of mycobacteria by PCR is described. The 1100bp fragment for internal control was produced from Streptomyces lividans DNA with the primers used for the rapid detection of mycobacteria by PCR. The amplified reaction consequently produced two products with 782bp for mycobacteria and 1100bp for the internal control extracted from all mycobacterial DNAs containing internal control so far examined. The 1100bp amplified fragment proved to be useful as an internal control with the same primer-binding sequence for the detection of mycobacteria.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC GENERAL MICROBIOLOGY  

Substrains of Mycobacterium bovis BCG (BCG) have been divided into two major groups, high and low producers, on the basis of the amount of secretion of the MPB70 protein. The antigen is produced in high concentration by BCG Tokyo, Moreau, Russia and Sweden (high-producer substrains), whereas in BCG Pasteur, Copenhagen and Tice (low-producer substrains) it is detected at 1% (w/w) or less of the concentration of BCG Tokyo. To investigate why this protein is secreted differently, the MPB70 genes of BCG Tokyo and Pasteur were cloned, sequenced and compared. The MPB70 genes in two substrains showed exactly the same sequence. Even the upstream and downstream regions of the MPB70 gene were identical. MPB70 gene expression was assessed by means of Northern hybridization analysis and reverse transcriptase polymerase chain reaction. The mRNA was clearly detected in BCG Tokyo, but at a very low level in BCG Pasteur. On the basis of these results, the difference in the secretion of the MPB70 protein between BCG Tokyo and Pasteur was attributed to differential transcription efficiencies.

DOI： 10.1099/13500872-141-7-1601

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The secreted protein MPB51 is one of the major proteins in the culture filtrate of Mycobacterium bovis BCG (BCG) and is a protein immunologically cross-reacting with the fibronectin binding 85 complex secreted by this bacterium. The gene encoding MPB51 (mpb51) was cloned, sequenced, and expressed in Escherichia coli. The mpb51 gene was mapped downstream of the gene for 85A component with 179 bp spaces. The mpb51 gene encoded 299 amino acids, including 33 amino acids for the signal peptide, followed by 266 amino acids for the mature protein with a molecular mass of 27807.37 Da. This is the first complete sequence of MPB51. MPB51 showed 37-43% homology to the components of 85 complex. Two-dimensional electrophoresis of culture fluids of BCG and Western blotting indicated the existence of the other novel protein(s) which strongly cross-reacted with the alpha antigen (85B) and MPB51.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

A pair of oligonucleotide primers, based on the experimentally determined amino terminal sequence of Mycobacterium bovis BCG ribosomal protein S12 (MboS12) and a highly conserved sequence found in all mycobacterial ribosomal S12 proteins, was used for polymerase chain reaction (PCR) with M. bovis genomic DNA as template. The nucleotide sequence of the 338 bp fragment thus produced confirmed its origin in MboS12 gene. A 5.0 kb EcoRI fragment of M. bovis DNA hybridizing to this fragment was cloned. Its sequencing analysis revealed the presence of two open reading frames in the same strand. Their amino acid sequences deduced from DNA sequence showed high homology with Escherichia coli ribosomal proteins S12 and S7. However, the intercistronic region between S12 and S7 genes, which plays an important role for autoregulation for the str operon in E. coli, is completely absent in M. bovis.

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MPB70 is known to be an immunogenic mycobacterial protein secreted in large amounts from Mycobacterium bovis BCG (BCG) Tokyo. The analogous gene for MPT70 was cloned from Mycobacterium tuberculosis H37Rv which produces this protein in only a small amount. The gene encoding 193 amino acid residues including 30 amino acids for the signal peptide, the promoter-like sequence, and the ribosome-binding site, was completely identical to that of BCG Tokyo. Computer analysis revealed that the carboxy-terminal half of MPT70 was homologous to amino acid sequences of fasciclin I, osteoblast-specific factor 2 (OSF-2), and human transforming growth factor-beta induced gene product (beta IG-H3). Escherichia coli (E. coli) -mycobacteria shuttle vectors containing mpt70 or mpb70 genes 0.7kbp upstream of the 5' end of them were able to be expressed in BCG Pasteur which is a MPB70 low-producer, but the extent of the expression was not that of a high-producer.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Actinomycetes Japan  

DOI： 10.3209/saj.9_228

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Other Link： http://search.jamas.or.jp/link/ui/1996082802

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Tuberculosis remains as major disease, affecting more than 20 million people. The elimination of the disease with vaccination, rapid diagnosis, and efficient therapy is an important objective of our study. To realize the objective, the characterization of antigens is essential. We have chosen two kinds of antigens for our study, the ribosomal antigens and an antigenic proteins secreted by mycobacteria. The biochemical and immunological characterization of ribosomal fraction was carried out. Ribosomal proteins were purified and assessed for DTH reaction. The N-terminal amino acids sequences were determined. Total structures of S19, S7 and S12 in 30S and L7/L12 in 50S subunits were elucidated. L7/L12 had 66% homology with analogue from S. griseus which showed GTPase activity in protein synthesis. This protein was secreted in culture medium and induced strong DTH. Secreted antigenic proteins are of great interest for us. Secreted antigens may he recognized rapidly by immune system and therefore may induce rapid and high level immune response. It is also expected that it may contain protective antigens, since live BCG protect disease more efficiently than heat killed BCG. We have determined and published the total structure of four proteins (MPB64, MPB70, MPB57, anti α antigen). We attempted to utilize this antigen for the diagnosis and the design of vaccine. The structures of a antigens from M. avium, M. intracellulare, M. scrofulaceum, M. kansasii and BCG were determined and its potential for application to diagnosis was presented. Using the operon of M. kansasii, α antigen anti V3 reagion of HIV-1 were expressed by recombinant BCG which induced CTL in mice.

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The homologue of groESL from Porphyromonas gingivalis was cloned and sequenced. Nucleotide sequencing suggested an operon containing two open reading frames (ORFs) homologous to groESL operon of Escherichia coli. The upstream ORF consisted of 267 bp corresponding to 89 amino acid residues. The downstream ORF consisted of 1635 bp corresponding to 545 amino acid residues.

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The homologue of groESL from Porphyromonas gingivalis was cloned and sequenced. Nucleotide sequencing suggested an operon containing two open reading frames (ORFs) homologous to groESL operon of Escherichia coli. The upstream ORF consisted of 267 bp corresponding to 89 amino acid residues. The downstream ORF consisted of 1635 bp corresponding to 545 amino acid residues. © 1994.

DOI： 10.1016/0167-4781(94)90265-8

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL SCIENCE LTD  

The gene for the extracellular a antigen of Mycobacterium scrofulaceum (S-a) was cloned by using the a antigen gene fragments of Mycobacterium bovis BCG as probes. The complete nucleotide sequence was determined. The gene was expressed in Escherichia coli. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein. The deduced amino acid sequences were highly homologous to the a antigen of the species of other mycobacteria. Interestingly, the a antigens of MAIS complex (Mycobacterium avium-Mycobacterium intracellulare- M. scrofulaceum) were closely homologous even at the C-terminal regions which were variable among those of M. bovis BCG, Mycobacterium leprae and Mycobacterium kansasii.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：BUTTERWORTH-HEINEMANN LTD  

The host immune response of cell-mediated immunity, particularly that of cytotoxic T lymphocytes (CTLs), is a major immune defence mechanism which may provide resistance to a human immunodeficiency virus type 1 (HIV-1) spread leading to acquired immune deficiency syndrome (AIDS). To prevent the accompanying activity of HIV-1 proteins responsible for the loss of helper T-lymphocyte function, it is crucial to develop a live attenuated recombinant vaccine expressing only T- or both T- and B-cell epitopes. Here, we examined the expression of the HIV-1 Env protein V3 region (15 amino acids from Arg(315) to Lys(329)) in Mycobacterium bovis BCG as a fused form with an extracellular alpha antigen of Mycobacterium kansasii. Balb/c mice inoculated with this recombinant BCG (rBCG), rapidly induced V3 peptide-specific CTLs. Target cell lysis was restricted to the murine class I major histocompatibility complex, H-2(d). A similar CTL response was also elicited after Balb/c mice were immunized with the same rBCG even when pre-inoculated with non-recombinant BCG. Thus, the rapid induction of HIV-1-specific CTLs indicates that this vaccine may be a therapeutic approach to preventing progression to AIDS.

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DOI： 10.1006/bbrc.1993.2417

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

DOI： 10.1006/bbrc.1993.2417

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Language：English   Publisher：AMER SOC MICROBIOLOGY  

Two proteins with molecular mass 65 kDa, a heat shock protein, and an S1-like protein were found in a 30S ribosomal subunit from Mycobacterium bovis BCG. The 17-kDa protein in the 30S subunit was homologous to alpha-crystallin heat shock protein, and the 16-kDa protein in the 50S subunit was homologous to the L7/L12 protein. The latter provoked a strong delayed-type hypersensitivity reaction in the sensitized guinea pigs. The GroES-like protein (12 kDa) loosely associated with ribosomes.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

The 30S ribosomal proteins from Mycobacterium bovis BCG were separated by reverse phase-high performance liquid chromatography (RP-HPLC). The isolated proteins were analyzed by SDS-PAGE, blotted on PVDF-membranes and subjected to sequence analyses using a gas-phase sequencer to correlate them to those of the well studied Escherichia coli and Bacillus stearothermophilus ribosomes. Moreover, the internal amino acid sequence of one ribosomal protein, MboS19, which is homologous to E. coli ribosomal protein S19 (EcoS19) and B. stearothermophilus ribosomal protein S19 (BstS19), was further analyzed by sequencing its internal peptides and two segments from the N- and C-termini of the protein were selected to deduce the sequence of two oligonucleotide primers which were used in a polymerase chain reaction. Using the amplified DNA fragment thus obtained as a hybridization probe, the gene encoding protein S19 was identified and cloned. Sequence analysis of the DNA fragment, together with peptide sequence analysis could determine the complete amino acid sequence of MboS19. This sequence proved to be 64% and 71% identical to those of the corresponding S19 proteins from the eubacteria E coli, and B. stearothermophilus, respectively; 33% of the residues of MboS19 were identical to those in the archaebacteral ribosomal protein HmaS19.

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Language：English   Publisher：OXFORD UNIV PRESS UNITED KINGDOM  

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The complete nucleotide sequence of alpha antigen secreted from Mycobacterium avium (A-alpha) was determined. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein with a molecular mass of 30,811 Da. This is the first sequence of A-alpha. Comparisons between A-alpha and alpha antigens of Mycobacterium leprae, Mycobacterium bovis BCG, and Mycobacterium kansasii showed highly homologous regions which suggested a conserved functional domain and two less-homologous regions. Serological analysis of recombinant A-alpha, expressed by a series of deletion constructs, indicated the possibility that A-alpha carries at least six B-cell epitopes. The three antigenic determinants were common to Mycobacterium tuberculosis, M. kansasii, and M. avium. The results also suggested the possibility that there are three species-specific epitopes.

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Responsible for pages：271-272   Language：English

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：(公社)日本薬学会  

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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J-GLOBAL

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(NPO)日本歯周病学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(一社)日本結核病学会  

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：岡山歯学会  

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Language：Japanese  

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(一社)日本歯科医学教育学会  

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Language：Japanese  

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Language：Japanese   Publisher：(一社)日本結核・非結核性抗酸菌症学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：WILEY-BLACKWELL  

Web of Science

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Language：Japanese  

J-GLOBAL

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Language：English   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(公社)日本矯正歯科学会  

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Language：Japanese   Publisher：(NPO)日本歯科保存学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese  

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Other Link： http://search.jamas.or.jp/link/ui/2013287201

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：(一社)歯科基礎医学会  

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Language：Japanese   Publisher：杏林書院  

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Other Link： http://search.jamas.or.jp/link/ui/2008041068

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Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Publisher：特定非営利活動法人 日本歯周病学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：(一社)日本結核病学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：FEDERATION AMER SOC EXP BIOL  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：FEDERATION AMER SOC EXP BIOL  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：Japanese   Publisher：歯科基礎医学会  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：FEDERATION AMER SOC EXP BIOL  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese  

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Language：Japanese   Publisher：産業医科大学学会  

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Other Link： http://search.jamas.or.jp/link/ui/1999177582

Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：日本細菌学会  

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Language：Japanese   Publisher：長崎大学  

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Language：Japanese   Publisher：長崎大学  

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Language：Japanese   Publisher：長崎大学  

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Language：Japanese   Publisher：日本ハンセン病学会  

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Language：English   Publisher：北海道大学  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Language：English   Publisher：Hokkaido University  

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Event date： 2016.10.15 - 2016.10.16

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山  

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Event date： 2016.8.24 - 2016.8.26

Language：English   Presentation type：Poster presentation  

Venue：札幌  

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Event date： 2016.8.24 - 2016.8.26

Language：English   Presentation type：Poster presentation  

Venue：札幌  

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