記述言語：日本語   出版者・発行元：(一社)日本結核・非結核性抗酸菌症学会  

[目的]全ゲノム解析を用いて,早期発症者と長期潜伏後発症者から分離した結核菌北京株のゲノム変異を解析した。[方法]1999年に中学校で発生した結核集団感染の接触者と二次感染者のうち2009年までに結核を発症した患者より分離した結核菌北京株6株と,別の事例で初発時と再発時の患者より分離した結核菌北京株2株の計8株の全ゲノム解析を行った。結核菌の突然変異率は,初発から1年以内に発症した早期発症者と1年以上の潜伏期を経てから発症または再燃した長期潜伏後発症者の2群間で比較した。[結果]結核菌北京株の突然変異率は,Lineage 4に属する結核菌よりも高く,結核菌北京株の高い病原性や薬剤耐性の要因である可能性が示唆された。遺伝子多型解析では,酸化的損傷に起因すると推定されている突然変異が長期潜伏後発症群のほうに多く,潜伏期間中にも薬剤耐性変異が起こる可能性が示唆された。[結論]結核菌北京株の高頻度の薬剤耐性化を防ぐためには,感染した結核菌の系統により治療法を検討する必要性も考えられた。今後,結核菌系統の特性を理解し,治療法を工夫することで結核の薬剤耐性化や重篤化を防ぐ有効な対策の構築につながることが期待される。(著者抄録)

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: Mycobacterium intracellulare is a representative etiological agent of emerging pulmonary M. avium-intracellulare complex disease in the industrialized countries worldwide. The recent genome sequencing of clinical strains isolated from pulmonary M. avium-intracellulare complex disease has provided insight into the genomic characteristics of pathogenic mycobacteria, especially for M. avium; however, the genomic characteristics of M. intracellulare remain to be elucidated. RESULTS: In this study, we performed comparative genomic analysis of 55 M. intracellulare and related strains such as M. paraintracellulare (MP), M. indicus pranii (MIP) and M. yonogonense. Based on the average nucleotide identity, the clinical M. intracellulare strains were phylogenetically grouped in two clusters: (1) the typical M. intracellulare (TMI) group, including ATCC13950 and virulent M.i.27 and M.i.198 that we previously reported, and (2) the MP-MIP group. The alignment of the genomic regions was mostly preserved between groups. Plasmids were identified between groups and subgroups, including a plasmid common among some strains of the M.i.27 subgroup. Several genomic regions including those encoding factors involved in lipid metabolism (e.g., fadE3, fadE33), transporters (e.g., mce3), and type VII secretion system (genes of ESX-2 system) were shown to be hypermutated in the clinical strains. M. intracellulare was shown to be pan-genomic at the species and subspecies levels. The mce genes were specific to particular subspecies, suggesting that these genes may be helpful in discriminating virulence phenotypes between subspecies. CONCLUSIONS: Our data suggest that genomic diversity among M. intracellulare, M. paraintracellulare, M. indicus pranii and M. yonogonense remains at the subspecies or genovar levels and does not reach the species level. Genetic components such as mce genes revealed by the comparative genomic analysis could be the novel focus for further insight into the mechanism of human pathogenesis for M. intracellulare and related strains.

DOI： 10.1186/s12866-021-02163-9

PubMed

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語  

[This corrects the article DOI: 10.1371/journal.pone.0204160.].

DOI： 10.1371/journal.pone.0256946

PubMed

researchmap

出版者・発行元：Research Square  

<title>Abstract</title>
DNA is basically an intracellular molecule that stores genetic information and carries instructions for growth and reproduction in all cellular organisms. However, in some bacteria, DNA has additional roles on the outside as an extracellular DNA (eDNA), an essential component for the formation of antibiotic tolerance bacteria in biofilm. Mycobacteria include life-threating human pathogens, most of which are slow growers. However, little is known about the nature of pathogenic mycobacteria’s eDNA. Here we found that eDNA is present in slow growers of mycobacterial pathogens, such as Mycobacterium tuberculosis, M. intracellulare, and M. avium at exponential growth phase. In contrast, eDNA is little in all tested rapid growers of mycobacteria. The physiological impact of disrupted eDNA on slow growers of mycobacteria include reduced formation of pellicle, a floating biofilm, and enhanced susceptibility to isoniazid and amikacin. Isolation and sequencing of eDNA revealed that it is identical to the genomic DNA in M. tuberculosis and M. intracellulare. In contrast, accumulation of phage DNA in eDNA of M. avium, suggests that the DNA released differs among mycobacterial species. Our data show important functions of eDNA for biofilm formation and drug tolerance in slow growers of mycobacteria.

DOI： 10.21203/rs.3.rs-109528/v1

researchmap

その他リンク： https://www.researchsquare.com/article/rs-109528/v1.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

<title>Abstract</title>
<italic>Mycobacterium tuberculosis</italic> (<italic>Mtb</italic>) strains of Beijing lineage have caused great concern because of their rapid emergence of drug resistance and worldwide spread. DNA mutation rates that reflect evolutional adaptation to host responses and the appearance of drug resistance have not been elucidated in human-infected Beijing strains. We tracked and obtained an original <italic>Mtb</italic> isolate of Beijing lineage from the 1999 tuberculosis outbreak in Japan, as well as five other isolates that spread in humans, and two isolates from the patient caused recurrence. Three isolates were from patients who developed TB within one year after infection (rapid-progressor, RP), and the other three isolates were from those who developed TB more than one year after infection (slow-progressor, SP). We sequenced genomes of these isolates and analyzed the propensity and rate of genomic mutations. Generation time versus mutation rate curves were significantly higher for RP. The ratio of oxidative versus non-oxidation damages induced mutations was higher in SP than RP, suggesting that persistent <italic>Mtb</italic> are exposed to oxidative stress in the latent state. Our data thus demonstrates that higher mutation rates of <italic>Mtb</italic> Beijing strains during human infection is likely to account for the higher adaptability and an emergence ratio of drug resistance.

DOI： 10.1038/s41598-020-75028-2

researchmap

その他リンク： http://www.nature.com/articles/s41598-020-75028-2

掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

<title>Abstract</title>The global incidence of the human nontuberculous mycobacteria (NTM) disease is rapidly increasing. However, knowledge of gene essentiality under optimal growth conditions and conditions relevant to the natural ecology of NTM, such as hypoxia, is lacking. In this study, we utilized transposon sequencing to comprehensively identify genes essential for growth in <italic>Mycobacterium intracellulare</italic>. Of 5126 genes of <italic>M. intracellulare</italic> ATCC13950, 506 genes were identified as essential genes, of which 280 and 158 genes were shared with essential genes of <italic>M. tuberculosis</italic> and <italic>M. marinum</italic>, respectively. The shared genes included target genes of existing antituberculous drugs including SQ109, which targets the trehalose monomycolate transporter MmpL3. From 175 genes showing decreased fitness as conditionally essential under hypoxia, preferential carbohydrate metabolism including gluconeogenesis, glyoxylate cycle and succinate production was suggested under hypoxia. Virulence-associated genes including proteasome system and mycothiol redox system were also identified as conditionally essential under hypoxia, which was further supported by the higher effective suppression of bacterial growth under hypoxia compared to aerobic conditions in the presence of these inhibitors. This study has comprehensively identified functions essential for growth of <italic>M. intracellulare</italic> under conditions relevant to the host environment. These findings provide critical functional genomic information for drug discovery.

DOI： 10.1038/s41598-020-62287-2

researchmap

その他リンク： http://www.nature.com/articles/s41598-020-62287-2

記述言語：日本語   出版者・発行元：(一社)日本結核・非結核性抗酸菌症学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OXFORD UNIV PRESS  

Macrophages are major components of tuberculosis (TB) granulomas and are responsible for host defenses against the intracellular pathogen, Mycobacterium tuberculosis. We herein showed the strong expression of hypoxia-inducible factor-1 alpha (HIF-1 alpha) in TB granulomas and more rapid death of HIF-1 alpha-conditional knockout mice than wild-type (WT) mice after M. tuberculosis infection. Although interferon-gamma (IFN-gamma) is a critical host-protective cytokine against intracellular pathogens, HIF-1-deficient macrophages permitted M. tuberculosis growth even after activation with IFN-gamma. These results prompted us to investigate the role of HIF-1 alpha in host defenses against infection. We found that the expression of lactate dehydrogenase-A (LDH-A) was controlled by HIF-1 alpha in M. tuberculosisinfected macrophages IFN-gamma independently. LDH-A is an enzyme that converts pyruvate to lactate and we found that the intracellular level of pyruvate in HIF-1 alpha-deficient bone marrow-derived macrophages (BMDMs) was significantly higher than in WT BMDMs. Intracellular bacillus replication was enhanced by an increase in intracellular pyruvate concentrations, which were decreased by LDH-A. Mycobacteria in phagosomes took up exogenous pyruvate more efficiently than glucose, and used it as the feasible carbon source for intracellular growth. These results demonstrate that HIF-1 alpha prevents the hijacking of pyruvate in macrophages, making it a fundamental host-protective mechanism against M. tuberculosis.

DOI： 10.1093/intimm/dxz048

Web of Science

PubMed

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.bjid.2019.07.001

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

One-third of the world's humans has latent tuberculosis infection (LTBI), representing a large pool of potentially active TB. Recent LTBI carries a higher risk of disease progression than remote LTBI. Recent studies suggest important roles of antibodies in TB pathology, prompting us to investigate serum antibody profiles in a cohort with LTBI. In this single-center prospective observational study, we analyzed IgG-antibody concentrations against five major Mycobacterium tuberculosis (Mtb) antigens (including 6 kDa early secretory antigenic target (ESAT6), CFP10, and antigen 85A, which are expressed mainly in the growth phase; and mycobacterial DNA-binding protein 1 (MDP1) and alpha-crystallin like protein (Acr), which are expressed in the dormant phases) in individuals with recent (n=13) or remote (n=12) LTBI, no Mtb infection (n=19), or active TB (n=15). Antibody titers against ESAT6 and MDP1 were significantly higher in individuals with recent LTBI than in those with no Mtb infection or remote LTBI. All pairwise antibody titers against these five major antigens were significantly correlated throughout the stages of Mtb infection. Five individuals with recent LTBI had significantly higher antibody titers against ESAT6 (P = 0.03), Ag85A (P = 0.048), Acr (P = 0.057), and MDP1 (P = 0.0001) than in individuals with remote LTBI; they were also outside the normal range (+2 SDs). One of these individuals was diagnosed with active pulmonary TB at 18-month follow-up examination. These findings indicated that concentrations of antibodies against both multiplying and dormant Mtb are higher in recent LTBI and that individuals with markedly higher antibody titers may be appropriate candidates for prophylactic therapy.

DOI： 10.1111/1348-0421.12674

PubMed

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Mycobacterium tuberculosis (M. tuberculosis) produces a diverse range of antigenic proteins in its dormant phase. The cytokine profiles of CD4+ T cell responses, especially subsets other than Th1 type (non-Th1 type), against these latency-associated M. tuberculosis antigens such as α-crystallin (Acr), heparin-binding hemagglutinin (HBHA), and mycobacterial DNA-binding protein 1 (MDP-1) remain elusive in relation to the clinical stage of M. tuberculosis infection. In the present study, peripheral blood mononuclear cells (PBMCs) collected from different stages of M. tuberculosis-infected cases and control PBMCs were stimulated with these antigens and ESAT-6/CFP-10. Cytokine profiles of CD4+ T cells were evaluated by intracellular cytokine staining using multicolor flow cytometry. Our results demonstrate that Th1 cytokine responses were predominant after TB onset independent of the type of antigen stimulation. On the contrary, non-Th1 cytokine responses were preferentially induced by latency-associated M. tuberculosis antigens, specifically IL-10 response against Acr in latent M. tuberculosis infection. From these results, we surmise a shift in the CD4+ T cell response from mixed non-Th1 to Th1 dominant type during TB progression.

DOI： 10.3389/fimmu.2019.02807

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Publishing Group  

Immune responses to parasitic pathogens are affected by the host physiological condition. High-density lipoprotein (HDL) and low-density lipoprotein (LDL) are transporters of lipids between the liver and peripheral tissues, and modulate pro-inflammatory immune responses. Pathogenic mycobacteria are parasitic intracellular bacteria that can survive within macrophages for a long period. Macrophage function is thus key for host defense against mycobacteria. These basic facts suggest possible effects of HDL and LDL on mycobacterial diseases, which have not been elucidated so far. In this study, we found that HDL and not LDL enhanced mycobacterial infections in human macrophages. Nevertheless, we observed that HDL remarkably suppressed production of tumor necrosis factor alpha (TNF-α) upon mycobacterial infections. TNF-α is a critical host-protective cytokine against mycobacterial diseases. We proved that toll-like receptor (TLR)-2 is responsible for TNF-α production by human macrophages infected with mycobacteria. Subsequent analysis showed that HDL downregulates TLR2 expression and suppresses its intracellular signaling pathways. This report demonstrates for the first time the substantial action of HDL in mycobacterial infections to human macrophages.

DOI： 10.1038/s41598-018-24233-1

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Tuberculosis causes the highest mortality among all single infections. Asymptomatic tuberculosis, afflicting one third of the global human population, is the major source as 5-10% of asymptomatic cases develop active tuberculosis during their lifetime. Thus it is one of important issues to develop diagnostic tools for accurately detecting asymptomatic infection. Mycobacterial DNA-binding protein 1 (MDP1) is a major protein in persistent Mycobacterium tuberculosis and has potential for diagnostic use in detecting asymptomatic infection. However, a previous ELISA-based study revealed a specificity problem; IgGs against MDP1 were detected in both M. tuberculosis-infected and uninfected individuals. Although the tertiary structures of an antigen are known to influence antibody recognition, the MDP1 structural details have not yet been investigated. The N-terminal half of MDP1, homologous to bacterial histone-like protein HU, is predicted to be responsible for DNA-binding, while the C-terminal half is assumed as totally intrinsically disordered regions. To clarify the relationship between the MDP1 tertiary structure and IgG recognition, we refined the purification method, which allow us to obtain a recombinant protein with the predicted structure. Furthermore, we showed that an IgG-ELISA using MDP1 purified by our refined method is indeed useful in the detection of asymptomatic tuberculosis.

DOI： 10.1371/journal.pone.0204160

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Public Library of Science  

Background: Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya. Methodology/Principal findings: We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soil-transmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the Kato-Katz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4–9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0–17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment. Conclusions/Significance: Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources.

DOI： 10.1371/journal.pntd.0005872

Scopus

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PUBLIC LIBRARY SCIENCE  

Background
Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya.
Methodology/Principal findings
We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soiltransmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the KatoKatz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4-9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0-17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment.
Conclusions/Significance
Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources.

DOI： 10.1371/journal.pntd.0005872

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

Bacteria can proliferate perpetually without ageing, but they also face conditions where they must persist. Mycobacteria can survive for a long period. This state appears during mycobacterial diseases such as tuberculosis and leprosy, which are chronic and develop after long-term persistent infections. However, the fundamental mechanisms of the long-term living of mycobacteria are unknown. Every Mycobacterium species expresses Mycobacterial DNA-binding protein 1 (MDP1), a histone-like nucleoid associated protein. Mycobacterium smegmatis is a saprophytic fast grower and used as a model of mycobacterial persistence, since it shares the characteristics of the long-term survival observed in pathogenic mycobacteria. Here we show that MDP1-deficient M. smegmatis dies more rapidly than the parental strain after entering stationary phase. Proteomic analyses revealed 21 upregulated proteins with more than 3-fold in MDP1-deficient strain, including DnaA, a replication initiator, NDH, a NADH dehydrogenase that catalyzes downhill electron transfer, Fas1, a critical fatty acid synthase, and antioxidants such as AhpC and KatG. Biochemical analyses showed elevated levels of DNA and ATP syntheses, a decreased NADH/NAD(+) ratio, and a loss of resistance to oxidative stress in the MDP1-knockout strain. This study suggests the importance of MDP1-dependent simultaneous control of the cellular functions in the long-term survival of mycobacteria.

DOI： 10.1038/s41598-017-06480-w

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0141658

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BIOMED CENTRAL LTD  

Background: Mycobacterium bovis bacillus Calmette Guerin (BCG) vaccine, which has been inoculated to more than one billion people world-wide, has significant effect in preventing tuberculous meningitis and miliary tuberculosis (TB) in neonate and early childhood. However, BCG fails to adequately protect against pulmonary TB and reactivation of latent infections in adults. To overcome this problem, adequate booster is urgently desired in adult who received prior BCG vaccination, and appropriate animal models that substitute human cases would be highly valuable for further experimentation.
Findings: The booster effect of the synthesized CpG oligomer (Oligo-B) on aged mice which had been primarily vaccinated with BCG at the age of 4-week old. The specific Th1 type reaction, production of interferon-gamma, in response to TB antigens, purified protein derivatives (PPD) and protection against challenge with Mycobacterium tuberculosis (MTB) H(37)Rv decreased with increasing age and were not observed in 89-week old mice. In order to rejuvenate the Th1 type response against PPD and protection activity against MTB infection, Oligo-B, which is known to augment Th1 responses, was administered as a booster to 81-90-week old mice (late 50's in human equivalent) vaccinated with BCG at 4-week old. The boosting with Oligo-B increased the number of CD4(+)CD44(high) CD62L(high), central memory type T cell. Furthermore, the Oligo-B boosting rejuvenated the ability of mice to protect against infection with MTB H(37)Rv.
Conclusions: Th1-adjuvant CpG oligo DNA, such as Oligo-B, may be a promising booster when coupled with BCG priming.

DOI： 10.1186/1742-4933-10-25

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

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

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：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

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

We report herein the draft genome sequence of Mycobacterium intracellulare clinical strain M.i.198, which consistently exhibits hypervirulence in human patients, human macrophages in vitro, and immunocompetent mice.

DOI： 10.1128/JB.01439-12

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC MICROBIOLOGY  

We report herein the draft genome sequence of Mycobacterium intracellulare clinical strain M.i.198, which consistently exhibits hypervirulence in human patients, human macrophages in vitro, and immunocompetent mice.

DOI： 10.1128/JB.01439-12

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Tuberculosis remains one of the most deadly infectious diseases worldwide and is a leading public health problem. Although isoniazid (INH) is a key drug for the treatment of tuberculosis, tolerance to INH necessitates prolonged treatment, which is a concern for effective tuberculosis chemotherapy. INH is a prodrug that is activated by the mycobacterial enzyme, KatG. Here, we show that mycobacterial DNA-binding protein 1 (MDP1), which is a histone-like protein conserved in mycobacteria, negatively regulates katG transcription and leads to phenotypic tolerance to INH in mycobacteria. Mycobacterium smegmatis deficient for MDP1 exhibited increased expression of KatG and showed enhanced INH activation compared with the wild-type strain. Expression of MDP1 was increased in the stationary phase and conferred growth phase-dependent tolerance to INH in M. smegmatis. Regulation of KatG expression is conserved between M. smegmatis and Mycobacterium tuberculosis complex. Artificial reduction of MDP1 in Mycobacterium bovis BCG was shown to lead to increased KatG expression and susceptibility to INH. These data suggest a mechanism by which phenotypic tolerance to INH is acquired in mycobacteri

DOI： 10.1074/jbc.M111.333385

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Tuberculosis remains one of the most deadly infectious diseases worldwide and is a leading public health problem. Although isoniazid (INH) is a key drug for the treatment of tuberculosis, tolerance to INH necessitates prolonged treatment, which is a concern for effective tuberculosis chemotherapy. INH is a prodrug that is activated by the mycobacterial enzyme, KatG. Here, we show that mycobacterial DNA-binding protein 1 (MDP1), which is a histone-like protein conserved in mycobacteria, negatively regulates katG transcription and leads to phenotypic tolerance to INH in mycobacteria. Mycobacterium smegmatis deficient for MDP1 exhibited increased expression of KatG and showed enhanced INH activation compared with the wild-type strain. Expression of MDP1 was increased in the stationary phase and conferred growth phase-dependent tolerance to INH in M. smegmatis. Regulation of KatG expression is conserved between M. smegmatis and Mycobacterium tuberculosis complex. Artificial reduction of MDP1 in Mycobacterium bovis BCG was shown to lead to increased KatG expression and susceptibility to INH. These data suggest a mechanism by which phenotypic tolerance to INH is acquired in mycobacteria.

DOI： 10.1074/jbc.M111.333385

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PUBLIC LIBRARY SCIENCE  

Infection and transmission of multidrug-resistant Mycobacterium tuberculosis (MDR-Mtb) and extensively drug-resistant M. tuberculosis (XDR-Mtb) is a serious health problem. We analyzed a total of 1,110 Mtb isolates in Osaka Prefecture and neighboring areas from April 2000 to March 2009. A total of 89 MDR-Mtb were identified, 36 (48.5%) of which were determined to be XDR-Mtb. Among the 89 MDR-Mtb isolates, 24 (27.0%) phylogenetically distributed into six clusters based on mycobacterial interspersed repetitive units-various number of tandem repeats (MIRU-VNTR) typing. Among these six clusters, the MIRU-VNTR patterns of four (OM-V02, OM-V03, OM-V04, and OM-V06) were only found for MDR-Mtb. Further analysis revealed that all isolates belonging to OM-V02 and OM-V03, and two isolates from OM-V04 were clonal. Importantly such genotypes were not observed for drug-sensitive isolates. These suggest that few but transmissible clones can transmit after acquiring multidrug resistance and colonize even in a country with a developed, well-organized healthcare system.

DOI： 10.1371/journal.pone.0042505

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

CD4(+)CD25(+) regulatory T (Treg) cells cause immune suppression by inhibiting T cell effector functions and play pivotal roles not only in self-tolerance but also in immune response to parasitic microbial pathogens. Mycobacteria are major parasitic bacterial pathogens, but the role of CD4(+)CD25(+) Treg cells in mycobacterial infection is not yet defined. In this study we found that, at the early stage of infection, depletion of CD25(+) cells reduced both bacterial load and granuloma formation in mice infected with Mycobacterium tuberculosis strains, such as M. tuberculosis Erdman or M. tuberculosis Kurono. However, at a later stage of infection, bacterial burden and histopathology were similar regardless of depletion of CD25(+) cells. Severe combined immunodeficient (SCID) mice reconstituted with CD4(+)CD25(-) T cells alone or a combination of CD4(+)CD25(+) and CD4(+)CD25(-) T cells showed similar bacterial loads and survival kinetics after infection with M. tuberculosis Erdman. Consistent with in vivo data, in vitro studies revealed that mycobacterial antigens, purified protein derivative of tuberculin (PPD), failed to induce the suppressive function of CD4(+)CD25(+) Treg ce

DOI： 10.1093/intimm/dxp126

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATL INST INFECTIOUS DISEASES  

Medical treatment of pulmonary Mycobacterium avium complex (MAC) disease does not always provide curative effects and is frequently hampered by recurrence. This suggests the presence of a reservoir for MAC in the environment surrounding patients. We previously reported the recovery of MAC isolates from the residential bathrooms of outpatients. In the present study, to ascertain the colonizing sites and the possibility of an MAC reservoir in the bathrooms of patients, we tested the recovery and the genetic diversity of MAC isolates from 6 sites of specimens, including 2 additional sampling sites, inside the showerhead and the bathtub inlet, in the residential bathrooms of patients with pulmonary MAC disease. MAC isolates were recovered from 15 out of the 29 bathrooms (52%), including specimens from 14 bathtub inlets and 3 showerheads. Nearly half of these bathrooms (7/15) contained MAC strains that were identical or similar to their respective clinical isolates. Additionally, in 5 out of 15 bathrooms, polyclonal colonization was revealed by pulsed-field gel electrophoresis. The results imply that colonization of MAC organisms in the bathrooms of MAC patients occurs predominantly in the bathtub inlets, and there is thus a risk of infection and/or reinfection for patients via use of the bathtub and other sites in the bathroom.

Web of Science

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Bacteria coordinate assembly of the cell wall as well as synthesis of cellular components depending on the growth state. The mycobacterial cell wall is dominated by mycolic acids covalently linked to sugars, such as trehalose and arabinose, and is critical for pathogenesis of mycobacteria. Transfer of mycolic acids to sugars is necessary for cell wall biogenesis and is mediated by mycolyltransferases, which have been previously identified as three antigen 85 (Ag85) complex proteins. However, the regulation mechanism which links cell wall biogenesis and the growth state has not been elucidated. Here we found that a histone-like protein has a dual concentration-dependent regulatory effect on mycolyltransferase functions of the Ag85 complex through direct binding to both the Ag85 complex and the substrate, trehalose-6-monomycolate, in the cell wall. A histone-like protein-deficient Mycobacterium smegmatis strain has an unusual crenellated cell wall structure and exhibits impaired cessation of glycolipid biosynthesis in the growth-retarded phase. Furthermore, we found that artificial alteration of the amount of the extracellular histone-like protein and the Ag85 complex changes the

DOI： 10.1128/JB.00550-07

PubMed

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

Mycobacterium consists up to 7% of mycobacterial DNA-binding protein 1 (MDP1) in total cellular proteins. Host immune responses to MDP1 were studied in mice to explore the antigenic properties of this protein. Anti-MDP1 IgG was produced after infection with either bacillus Calmette-Guerin or Mycobacterium tuberculosis in C3H/HeJ mice. However, the level of Ab was remarkably low when purified MDPI was injected. MDPI is considered to be associated with DNA in nucleoid, which contains immunostimulatory CpG motif. Therefore, we examined coadministration of MDPI and DNA derived from M. tuberculosis. Consequently, this procedure significantly enhanced the production of MDP1-specific IgG. Five nanograms of DNA was enough to enhance MDP1-specific IgG production in the administration of 5 mu g of MDP1 into mice. Strong immune stimulation by such a small amount of DNA is noteworthy, because &gt; 1,000- to 100,000-fold doses of CpG DNAs are used for immune activation. A synthetic peptide-based study showed that B cell epitopes were different between mice administered MDPI alone and those given a mixture of MDP1 and DNA, suggesting that DNA alters the three-dimensional structure of MDP1. Coadministration of DNA also enhanced MDP1-specific IFN-gamma production and reduced the bacterial burden of a following challenge of M. tuberculosis, showing that MDP1 is a novel vaccine target. Finally, we found that MDP1 remarkably enhanced TLR9-dependent immune stimulation by unmethylated CpG oligo DNA in vitro. To our knowledge, MDPI is the first protein discovered that remarkably augments the CpG-mediated immune response and is a potential adjuvant for CpG DNA-based immune therapies.

Web of Science

PubMed

researchmap

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(株)医学書院  

＜文献概要＞Point ・結核菌は活性化されたマクロファージや樹状細胞での殺菌に抵抗する細胞内寄生性病原体である.・結核菌抗原により誘導されたT細胞を中心とする獲得免疫は多彩で菌の排除を促進するものと許容するものがある.・菌はこのように相反する宿主免疫機構を利用するがごとくに,生体内で排除されず長期の寄生や疾患が成立する.

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：(公社)日本栄養・食糧学会  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：大阪市医学会  

結核は、発症者が900万人を超える世界最大の感染症であり、その病原菌Mycobacterium tuberculosisの感染に伴う主に肺肉芽腫を形成する疾患である。全世界人類の3分の1はM.tuberculosisに感染し、無症候状態の潜在性結核と考えられている。潜在性結核の約5%は、内因性再燃に伴い結核を発症することから、潜在性結核に対処することが重要である。結核患者の多くは開発途上国のアジア(55%)とアフリカ(30%)に集中しており、先進国ではほぼ制圧されているように窺える。しかし、最近では、渡航者によって病原菌が伝播されている。さらに、多剤耐性結核菌の出現やヒト免疫不全ウイルス感染者の約26%は結核感染者であることから、今後、結核が流行する可能性がある。結核制圧のためには、活動性結核に加え潜在性結核の早期診断・早期治療が重要だと考えられる。しかし、現在の結核診断法に用いられているインターフェロン-γ産生法(クオンティフェロン)やツベルクリン反応は、潜在性結核を十分に診断できない。そこで、我々は、23種の結核菌抗原を用いて潜在性結核のバイオマーカー探索を開始した。国内で行った研究結果から潜在性結核のバイオマーカーとして4種の抗原候補を見いだし、さらに長崎大学熱帯医学研究所との共同研究によりケニアでの結核感染調査においてもその有用性を確認した。現在、潜在性結核のバイオマーカー探索が世界中で取り組まれている中、我々の研究結果は、新たな潜在性結核の診断法へと繋がる可能性が考えられる。(著者抄録)

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：日本細菌学会  

researchmap

記述言語：英語   出版者・発行元：ELSEVIER SCI LTD  

Mycobacterium bovis bacillus Calmette-Guerin (BCG) is the most often used vaccine worldwide and sole vaccine against tuberculosis. BCG is protective against severe form of childhood tuberculosis but less or not protective to adult pulmonary tuberculosis. Therefore, improved vaccination strategies and development of new tuberculosis vaccines are urgent demands. For those purposes, appropriate animal models that reflect human are critically useful. However, in animal models, BCG vaccination protects well against subsequent challenge of Mycobacterium tuberculosis. In this study we evaluated the duration of protective efficacy of the BCG vaccination in mice over time and found that efficacy was diminished 40 weeks after vaccination. The aged mice older than 45 weeks are protected sufficiently after the vaccination with BCG, suggesting that loss of its efficacy is not dependent on the age of mice but rather depends on the period from vaccination. The loss of protection occurred in TH1 polarized STAT6 deficient mice despite the maintenance of interferon (IFN)-gamma production activity of lymph node cells and splenic CD4(+) T cells against M. tuberculosis antigens. Our data suggest that the duration from vaccination may explain the variation in BCG efficacy against adult pulmonary tuberculosis. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vaccine.2011.07.051

Web of Science

researchmap

記述言語：英語   出版者・発行元：ELSEVIER SCI LTD  

Mycobacterium bovis bacillus Calmette-Guerin (BCG) is the most often used vaccine worldwide and sole vaccine against tuberculosis. BCG is protective against severe form of childhood tuberculosis but less or not protective to adult pulmonary tuberculosis. Therefore, improved vaccination strategies and development of new tuberculosis vaccines are urgent demands. For those purposes, appropriate animal models that reflect human are critically useful. However, in animal models, BCG vaccination protects well against subsequent challenge of Mycobacterium tuberculosis. In this study we evaluated the duration of protective efficacy of the BCG vaccination in mice over time and found that efficacy was diminished 40 weeks after vaccination. The aged mice older than 45 weeks are protected sufficiently after the vaccination with BCG, suggesting that loss of its efficacy is not dependent on the age of mice but rather depends on the period from vaccination. The loss of protection occurred in TH1 polarized STAT6 deficient mice despite the maintenance of interferon (IFN)-gamma production activity of lymph node cells and splenic CD4(+) T cells against M. tuberculosis antigens. Our data suggest that the duration from vaccination may explain the variation in BCG efficacy against adult pulmonary tuberculosis. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.vaccine.2011.07.051

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

researchmap

記述言語：英語   出版者・発行元：OXFORD UNIV PRESS  

CD4(+)CD25(+) regulatory T (Treg) cells cause immune suppression by inhibiting T cell effector functions and play pivotal roles not only in self-tolerance but also in immune response to parasitic microbial pathogens. Mycobacteria are major parasitic bacterial pathogens, but the role of CD4(+)CD25(+) Treg cells in mycobacterial infection is not yet defined. In this study we found that, at the early stage of infection, depletion of CD25(+) cells reduced both bacterial load and granuloma formation in mice infected with Mycobacterium tuberculosis strains, such as M. tuberculosis Erdman or M. tuberculosis Kurono. However, at a later stage of infection, bacterial burden and histopathology were similar regardless of depletion of CD25(+) cells. Severe combined immunodeficient (SCID) mice reconstituted with CD4(+)CD25(-) T cells alone or a combination of CD4(+)CD25(+) and CD4(+)CD25(-) T cells showed similar bacterial loads and survival kinetics after infection with M. tuberculosis Erdman. Consistent with in vivo data, in vitro studies revealed that mycobacterial antigens, purified protein derivative of tuberculin (PPD), failed to induce the suppressive function of CD4(+)CD25(+) Treg cells to CD4(+)CD25(-) effector T cells, as demonstrated by the lack of response of CD4(+)CD25(+) T cells to PPD, in mice chronically infected with Mycobacterium bovis bacillus Calmette-Guerin and M. tuberculosis. Our data show that CD4(+)CD25(+) Treg cells have a transient effect at the early stage of mycobacterial infection but, contrary to the expectation, have little impact on the overall course of infection.

DOI： 10.1093/intimm/dxp126

Web of Science

PubMed

researchmap

記述言語：英語   出版者・発行元：OXFORD UNIV PRESS  

CD4(+)CD25(+) regulatory T (Treg) cells cause immune suppression by inhibiting T cell effector functions and play pivotal roles not only in self-tolerance but also in immune response to parasitic microbial pathogens. Mycobacteria are major parasitic bacterial pathogens, but the role of CD4(+)CD25(+) Treg cells in mycobacterial infection is not yet defined. In this study we found that, at the early stage of infection, depletion of CD25(+) cells reduced both bacterial load and granuloma formation in mice infected with Mycobacterium tuberculosis strains, such as M. tuberculosis Erdman or M. tuberculosis Kurono. However, at a later stage of infection, bacterial burden and histopathology were similar regardless of depletion of CD25(+) cells. Severe combined immunodeficient (SCID) mice reconstituted with CD4(+)CD25(-) T cells alone or a combination of CD4(+)CD25(+) and CD4(+)CD25(-) T cells showed similar bacterial loads and survival kinetics after infection with M. tuberculosis Erdman. Consistent with in vivo data, in vitro studies revealed that mycobacterial antigens, purified protein derivative of tuberculin (PPD), failed to induce the suppressive function of CD4(+)CD25(+) Treg cells to CD4(+)CD25(-) effector T cells, as demonstrated by the lack of response of CD4(+)CD25(+) T cells to PPD, in mice chronically infected with Mycobacterium bovis bacillus Calmette-Guerin and M. tuberculosis. Our data show that CD4(+)CD25(+) Treg cells have a transient effect at the early stage of mycobacterial infection but, contrary to the expectation, have little impact on the overall course of infection.

DOI： 10.1093/intimm/dxp126

Web of Science

PubMed

CiNii Article

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：PUBLIC LIBRARY SCIENCE  

In spite of the importance of hyaluronan in host protection against infectious organisms in the alveolar spaces, its role in mycobacterial infection is unknown. In a previous study, we found that mycobacteria interact with hyaluronan on lung epithelial cells. Here, we have analyzed the role of hyaluronan after mycobacterial infection was established and found that pathogenic mycobacteria can grow by utilizing hyaluronan as a carbon source. Both mouse and human possess 3 kinds of hyaluronan synthases (HAS), designated HAS1, HAS2, and HAS3. Utilizing individual HAS-transfected cells, we show that HAS1 and HAS3 but not HAS2 support growth of mycobacteria. We found that the major hyaluronan synthase expressed in the lung is HAS1, and that its expression was increased after infection with Mycobacterium tuberculosis. Histochemical analysis demonstrated that hyaluronan profoundly accumulated in the granulomatous legion of the lungs in M. tuberculosis-infected mice and rhesus monkeys that died from tuberculosis. We detected hyaluronidase activity in the lysate of mycobacteria and showed that it was critical for hyaluronan-dependent extracellular growth. Finally, we showed that L-Ascorbic acid 6-hexadecanoate, a hyaluronidase inhibitor, suppressed growth of mycobacteria in vivo. Taken together, our data show that pathogenic mycobacteria exploit an intrinsic host-protective molecule, hyaluronan, to grow in the respiratory tract and demonstrate the potential usefulness of hyaluronidase inhibitors against mycobacterial diseases.

DOI： 10.1371/journal.ppat.1000643

Web of Science

researchmap

記述言語：英語   出版者・発行元：PUBLIC LIBRARY SCIENCE  

In spite of the importance of hyaluronan in host protection against infectious organisms in the alveolar spaces, its role in mycobacterial infection is unknown. In a previous study, we found that mycobacteria interact with hyaluronan on lung epithelial cells. Here, we have analyzed the role of hyaluronan after mycobacterial infection was established and found that pathogenic mycobacteria can grow by utilizing hyaluronan as a carbon source. Both mouse and human possess 3 kinds of hyaluronan synthases (HAS), designated HAS1, HAS2, and HAS3. Utilizing individual HAS-transfected cells, we show that HAS1 and HAS3 but not HAS2 support growth of mycobacteria. We found that the major hyaluronan synthase expressed in the lung is HAS1, and that its expression was increased after infection with Mycobacterium tuberculosis. Histochemical analysis demonstrated that hyaluronan profoundly accumulated in the granulomatous legion of the lungs in M. tuberculosis-infected mice and rhesus monkeys that died from tuberculosis. We detected hyaluronidase activity in the lysate of mycobacteria and showed that it was critical for hyaluronan-dependent extracellular growth. Finally, we showed that L-Ascorbic acid 6-hexadecanoate, a hyaluronidase inhibitor, suppressed growth of mycobacteria in vivo. Taken together, our data show that pathogenic mycobacteria exploit an intrinsic host-protective molecule, hyaluronan, to grow in the respiratory tract and demonstrate the potential usefulness of hyaluronidase inhibitors against mycobacterial diseases.

DOI： 10.1371/journal.ppat.1000643

Web of Science

researchmap

記述言語：英語   出版者・発行元：NATL INST INFECTIOUS DISEASES  

Medical treatment of pulmonary Mycobacterium avium complex (MAC) disease does not always provide curative effects and is frequently hampered by recurrence. This suggests the presence of a reservoir for MAC in the environment surrounding patients. We previously reported the recovery of MAC isolates from the residential bathrooms of outpatients. In the present study, to ascertain the colonizing sites and the possibility of an MAC reservoir in the bathrooms of patients, we tested the recovery and the genetic diversity of MAC isolates from 6 sites of specimens, including 2 additional sampling sites, inside the showerhead and the bathtub inlet, in the residential bathrooms of patients with pulmonary MAC disease. MAC isolates were recovered from 15 out of the 29 bathrooms (52%), including specimens from 14 bathtub inlets and 3 showerheads. Nearly half of these bathrooms (7/15) contained MAC strains that were identical or similar to their respective clinical isolates. Additionally, in 5 out of 15 bathrooms, polyclonal colonization was revealed by pulsed-field gel electrophoresis. The results imply that colonization of MAC organisms in the bathrooms of MAC patients occurs predominantly in the bathtub inlets, and there is thus a risk of infection and/or reinfection for patients via use of the bathtub and other sites in the bathroom.

Web of Science

researchmap

記述言語：英語   出版者・発行元：NATL INST INFECTIOUS DISEASES  

Medical treatment of pulmonary Mycobacterium avium complex (MAC) disease does not always provide curative effects and is frequently hampered by recurrence. This suggests the presence of a reservoir for MAC in the environment surrounding patients. We previously reported the recovery of MAC isolates from the residential bathrooms of outpatients. In the present study, to ascertain the colonizing sites and the possibility of an MAC reservoir in the bathrooms of patients, we tested the recovery and the genetic diversity of MAC isolates from 6 sites of specimens, including 2 additional sampling sites, inside the showerhead and the bathtub inlet, in the residential bathrooms of patients with pulmonary MAC disease. MAC isolates were recovered from 15 out of the 29 bathrooms (52%), including specimens from 14 bathtub inlets and 3 showerheads. Nearly half of these bathrooms (7/15) contained MAC strains that were identical or similar to their respective clinical isolates. Additionally, in 5 out of 15 bathrooms, polyclonal colonization was revealed by pulsed-field gel electrophoresis. The results imply that colonization of MAC organisms in the bathrooms of MAC patients occurs predominantly in the bathtub inlets, and there is thus a risk of infection and/or reinfection for patients via use of the bathtub and other sites in the bathroom.

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD  

Mycobacterium avium complex (MAC) disease has been increasing worldwide not only in immunocompromised but also in immunocompetent humans. However, the relationship between mycobacterial strain virulence and disease progression in immunocompetent humans is unclear. In this study, we isolated 6 strains from patients with pulmonary MAC disease. To explore the virulence, we examined the growth in human THP-1 macrophages and pathogenicity in C57BL/6 mice. We found that one strain, designated 198, which was isolated from a patient showing the most progressive disease, persisted in THP-1 cells. In addition, strain 198 grew to a high bacterial load with strong inflammation in mouse lungs and spleens 16 weeks after infection. To our knowledge, strain 198 is the first isolated MAC strain that exhibits hypervirulence consistently for the human patient, human macrophages in vitro, and even for immunocompetent mice. Other strains showed limited survival and weak virulence both in macrophages and in mice, uncorrelated to disease progression in human patients. We demonstrated that there is a hypervirulent clinical MAC strain whose experimental virulence corresponds to the serious disease progression in the patients. The existence of such strain suggests the involvement of bacterial virulence in the pathogenesis of pulmonary MAC disease in immunocompetent status. (c) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2008.10.007

Web of Science

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD  

Mycobacterium avium complex (MAC) disease has been increasing worldwide not only in immunocompromised but also in immunocompetent humans. However, the relationship between mycobacterial strain virulence and disease progression in immunocompetent humans is unclear. In this study, we isolated 6 strains from patients with pulmonary MAC disease. To explore the virulence, we examined the growth in human THP-1 macrophages and pathogenicity in C57BL/6 mice. We found that one strain, designated 198, which was isolated from a patient showing the most progressive disease, persisted in THP-1 cells. In addition, strain 198 grew to a high bacterial load with strong inflammation in mouse lungs and spleens 16 weeks after infection. To our knowledge, strain 198 is the first isolated MAC strain that exhibits hypervirulence consistently for the human patient, human macrophages in vitro, and even for immunocompetent mice. Other strains showed limited survival and weak virulence both in macrophages and in mice, uncorrelated to disease progression in human patients. We demonstrated that there is a hypervirulent clinical MAC strain whose experimental virulence corresponds to the serious disease progression in the patients. The existence of such strain suggests the involvement of bacterial virulence in the pathogenesis of pulmonary MAC disease in immunocompetent status. (c) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2008.10.007

Web of Science

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD  

Mycobacterium avium complex (MAC) disease has been increasing worldwide not only in immunocompromised but also in immunocompetent humans. However, the relationship between mycobacterial strain virulence and disease progression in immunocompetent humans is unclear. In this study, we isolated 6 strains from patients with pulmonary MAC disease. To explore the virulence, we examined the growth in human THP-1 macrophages and pathogenicity in C57BL/6 mice. We found that one strain, designated 198, which was isolated from a patient showing the most progressive disease, persisted in THP-1 cells. In addition, strain 198 grew to a high bacterial load with strong inflammation in mouse lungs and spleens 16 weeks after infection. To our knowledge, strain 198 is the first isolated MAC strain that exhibits hypervirulence consistently for the human patient, human macrophages in vitro, and even for immunocompetent mice. Other strains showed limited survival and weak virulence both in macrophages and in mice, uncorrelated to disease progression in human patients. We demonstrated that there is a hypervirulent clinical MAC strain whose experimental virulence corresponds to the serious disease progression in the patients. The existence of such strain suggests the involvement of bacterial virulence in the pathogenesis of pulmonary MAC disease in immunocompetent status. (c) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2008.10.007

Web of Science

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD  

Mycobacterium avium complex (MAC) disease has been increasing worldwide not only in immunocompromised but also in immunocompetent humans. However, the relationship between mycobacterial strain virulence and disease progression in immunocompetent humans is unclear. In this study, we isolated 6 strains from patients with pulmonary MAC disease. To explore the virulence, we examined the growth in human THP-1 macrophages and pathogenicity in C57BL/6 mice. We found that one strain, designated 198, which was isolated from a patient showing the most progressive disease, persisted in THP-1 cells. In addition, strain 198 grew to a high bacterial load with strong inflammation in mouse lungs and spleens 16 weeks after infection. To our knowledge, strain 198 is the first isolated MAC strain that exhibits hypervirulence consistently for the human patient, human macrophages in vitro, and even for immunocompetent mice. Other strains showed limited survival and weak virulence both in macrophages and in mice, uncorrelated to disease progression in human patients. We demonstrated that there is a hypervirulent clinical MAC strain whose experimental virulence corresponds to the serious disease progression in the patients. The existence of such strain suggests the involvement of bacterial virulence in the pathogenesis of pulmonary MAC disease in immunocompetent status. (c) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2008.10.007

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：AMER SOC MICROBIOLOGY  

Bacteria coordinate assembly of the cell wall as well as synthesis of cellular components depending on the growth state. The mycobacterial cell wall is dominated by mycolic acids covalently linked to sugars, such as trehalose and arabinose, and is critical for pathogenesis of mycobacteria. Transfer of mycolic acids to sugars is necessary for cell wall biogenesis and is mediated by mycolyltransferases, which have been previously identified as three antigen 85 (Ag85) complex proteins. However, the regulation mechanism which links cell wall biogenesis and the growth state has not been elucidated. Here we found that a histone-like protein has a dual concentration-dependent regulatory effect on mycolyltransferase functions of the Ag85 complex through direct binding to both the Ag85 complex and the substrate, trehalose-6-monomycolate, in the cell wall. A histone-like protein-deficient Mycobacterium smegmatis strain has an unusual crenellated cell wall structure and exhibits impaired cessation of glycolipid biosynthesis in the growth-retarded phase. Furthermore, we found that artificial alteration of the amount of the extracellular histone-like protein and the Ag85 complex changes the growth rate of mycobacteria, perhaps due to impaired down-regulation of glycolipid biosynthesis. Our results demonstrate novel regulation of cell wall assembly which has an impact on bacterial growth.

DOI： 10.1128/JB.00550-07

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   出版者・発行元：AMER SOC MICROBIOLOGY  

Bacteria coordinate assembly of the cell wall as well as synthesis of cellular components depending on the growth state. The mycobacterial cell wall is dominated by mycolic acids covalently linked to sugars, such as trehalose and arabinose, and is critical for pathogenesis of mycobacteria. Transfer of mycolic acids to sugars is necessary for cell wall biogenesis and is mediated by mycolyltransferases, which have been previously identified as three antigen 85 (Ag85) complex proteins. However, the regulation mechanism which links cell wall biogenesis and the growth state has not been elucidated. Here we found that a histone-like protein has a dual concentration-dependent regulatory effect on mycolyltransferase functions of the Ag85 complex through direct binding to both the Ag85 complex and the substrate, trehalose-6-monomycolate, in the cell wall. A histone-like protein-deficient Mycobacterium smegmatis strain has an unusual crenellated cell wall structure and exhibits impaired cessation of glycolipid biosynthesis in the growth-retarded phase. Furthermore, we found that artificial alteration of the amount of the extracellular histone-like protein and the Ag85 complex changes the growth rate of mycobacteria, perhaps due to impaired down-regulation of glycolipid biosynthesis. Our results demonstrate novel regulation of cell wall assembly which has an impact on bacterial growth.

DOI： 10.1128/JB.00550-07

Web of Science

PubMed

CiNii Article

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

We aimed to reveal the regulatory function of macrophage scavenger receptor-A (MSR-A) in proinflammatory cytokine production by macrophages stimulated with rnycobacterial cord factor (CF). By the culture with CF, MSR-A (+/+) alveolar macrophages and Kupffer cells produced TNF-alpha/MIP-1 alpha in a time- and dose-dependent manner However, the amounts of cytokines produced by them were much less compared to those produced by MSR-A (-/-) macrophages. Consistent with this, treatment of MSR-A (+/+) macrophages with anti-MSR-A antibody increased TNF-alpha. production. Binding of CF to MSR-A was demonstrated by measuring the binding affinity. These. results indicate that CF binds MSR-A, and MSR-A down-regulates TNF-alpha/MIP-1 alpha. production by activated macrophages, suggesting the role of this receptor in suppression of excessive inflammatory responses during mycobacterial infection. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2005.12.006

Web of Science

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

We aimed to reveal the regulatory function of macrophage scavenger receptor-A (MSR-A) in proinflammatory cytokine production by macrophages stimulated with rnycobacterial cord factor (CF). By the culture with CF, MSR-A (+/+) alveolar macrophages and Kupffer cells produced TNF-alpha/MIP-1 alpha in a time- and dose-dependent manner However, the amounts of cytokines produced by them were much less compared to those produced by MSR-A (-/-) macrophages. Consistent with this, treatment of MSR-A (+/+) macrophages with anti-MSR-A antibody increased TNF-alpha. production. Binding of CF to MSR-A was demonstrated by measuring the binding affinity. These. results indicate that CF binds MSR-A, and MSR-A down-regulates TNF-alpha/MIP-1 alpha. production by activated macrophages, suggesting the role of this receptor in suppression of excessive inflammatory responses during mycobacterial infection. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.micpath.2005.12.006

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

Mycobacterium consists up to 7% of mycobacterial DNA-binding protein 1 (MDP1) in total cellular proteins. Host immune responses to MDP1 were studied in mice to explore the antigenic properties of this protein. Anti-MDP1 IgG was produced after infection with either bacillus Calmette-Guerin or Mycobacterium tuberculosis in C3H/HeJ mice. However, the level of Ab was remarkably low when purified MDPI was injected. MDPI is considered to be associated with DNA in nucleoid, which contains immunostimulatory CpG motif. Therefore, we examined coadministration of MDPI and DNA derived from M. tuberculosis. Consequently, this procedure significantly enhanced the production of MDP1-specific IgG. Five nanograms of DNA was enough to enhance MDP1-specific IgG production in the administration of 5 mu g of MDP1 into mice. Strong immune stimulation by such a small amount of DNA is noteworthy, because &gt; 1,000- to 100,000-fold doses of CpG DNAs are used for immune activation. A synthetic peptide-based study showed that B cell epitopes were different between mice administered MDPI alone and those given a mixture of MDP1 and DNA, suggesting that DNA alters the three-dimensional structure of MDP1. Coadministration of DNA also enhanced MDP1-specific IFN-gamma production and reduced the bacterial burden of a following challenge of M. tuberculosis, showing that MDP1 is a novel vaccine target. Finally, we found that MDP1 remarkably enhanced TLR9-dependent immune stimulation by unmethylated CpG oligo DNA in vitro. To our knowledge, MDPI is the first protein discovered that remarkably augments the CpG-mediated immune response and is a potential adjuvant for CpG DNA-based immune therapies.

Web of Science

researchmap

記述言語：英語   出版者・発行元：AMER ASSOC IMMUNOLOGISTS  

Mycobacterium consists up to 7% of mycobacterial DNA-binding protein 1 (MDP1) in total cellular proteins. Host immune responses to MDP1 were studied in mice to explore the antigenic properties of this protein. Anti-MDP1 IgG was produced after infection with either bacillus Calmette-Guerin or Mycobacterium tuberculosis in C3H/HeJ mice. However, the level of Ab was remarkably low when purified MDPI was injected. MDPI is considered to be associated with DNA in nucleoid, which contains immunostimulatory CpG motif. Therefore, we examined coadministration of MDPI and DNA derived from M. tuberculosis. Consequently, this procedure significantly enhanced the production of MDP1-specific IgG. Five nanograms of DNA was enough to enhance MDP1-specific IgG production in the administration of 5 mu g of MDP1 into mice. Strong immune stimulation by such a small amount of DNA is noteworthy, because &gt; 1,000- to 100,000-fold doses of CpG DNAs are used for immune activation. A synthetic peptide-based study showed that B cell epitopes were different between mice administered MDPI alone and those given a mixture of MDP1 and DNA, suggesting that DNA alters the three-dimensional structure of MDP1. Coadministration of DNA also enhanced MDP1-specific IFN-gamma production and reduced the bacterial burden of a following challenge of M. tuberculosis, showing that MDP1 is a novel vaccine target. Finally, we found that MDP1 remarkably enhanced TLR9-dependent immune stimulation by unmethylated CpG oligo DNA in vitro. To our knowledge, MDPI is the first protein discovered that remarkably augments the CpG-mediated immune response and is a potential adjuvant for CpG DNA-based immune therapies.

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語   出版者・発行元：大阪国際大学  

During practical training in food service, it is important for students of dietetics courses to learn the principles of Hazard Analysis and Critical Control Point （HACCP） and consider how to prevent food borne illness. Thus, microbial contamination was examined at several points in the cooking process of a potato salad during food service training in order to provide feedback in hygiene education for students. Samples were collected from fresh vegetables （cucumbers, onions, potatoes, mini-tomatoes, and butter lettuce） before and after washing as well as steamed vegetables （cucumbers, onions, potatoes）. Samples were also collected from salad dressing, freshly cooked potato salad, salad stored for 1 hour and preserved for 2 hours at 5 degree C. The microbiological contamination was determined from Aerobic plate count （APC） and Coliforms using the petrifilm plate method. The APC of the fresh vegetables before washing were 0.9 to 6.1 log CFU/g and the range for the Colifoms was 2.8 or less log CFU/g. The contamination levels of the vegetables were not significantly reduced by washing. Steaming was effective in the reduction of microbial contamination levels. The APC and Coliforms increased during storage of the potato salad prepared with raw vegetables （mini-tomatoes and butter lettuce）. These results indicate that raw vegetables should be effectively washed to reduce microbial contamination levels and attention paid to preparation time for salads.

CiNii Article

CiNii Books

J-GLOBAL

researchmap

researchmap

記述言語：英語   出版者・発行元：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Mycobacterium tuberculosis infects not only host macrophages but also nonprofessional phagocytes, such as alveolar epithelial cells. Glycosaminoglycans (GAGs) are considered as the component of mycobacterial adherence to epithelial cells. Here we show that extracellularly occurring mycobacterial DNA-binding protein 1 (MDP1) promotes mycobacterial infection to A549 human lung epithelial cells through hyaluronic acid ( HA). Both surface plasmon resonance analysis and enzyme-linked immunosorbent assay revealed that MDP1 bound to HA, heparin, and chondroitin sulfate. Utilizing synthetic peptides, we next defined heparin-binding site of 20 amino acids from 31 to 50 of MDP1, which is responsible for the specific DNA-binding site of MDP1. MDP1 bound to A549 cells, and exogenous DNA and HA interfered with the interaction. The binding was also abolished by treatment of A549 cells with hyaluronidase, suggesting that HA participates in the MDP1-A549 cell interaction. Adherence of bacillus Calmette-Guerin ( BCG) and M. tuberculosis to A549 cells was inhibited by addition of HA, DNA, and anti-MDP1 antibody, showing that MDP1 participates in the interaction between mycobacteria-alveolar epithelial cells. Simultaneous treatment of intratracheal BCG-infected mice with HA reduced the growth of BCG in vivo. Taken together, theses results suggest that HA participates in Mycobacterium-lung epithelium interaction and has potential for therapeutic and prophylactic interventions in mycobacterial infection.

DOI： 10.1074/jbc.M402677200

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   出版者・発行元：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Mycobacterium tuberculosis infects not only host macrophages but also nonprofessional phagocytes, such as alveolar epithelial cells. Glycosaminoglycans (GAGs) are considered as the component of mycobacterial adherence to epithelial cells. Here we show that extracellularly occurring mycobacterial DNA-binding protein 1 (MDP1) promotes mycobacterial infection to A549 human lung epithelial cells through hyaluronic acid ( HA). Both surface plasmon resonance analysis and enzyme-linked immunosorbent assay revealed that MDP1 bound to HA, heparin, and chondroitin sulfate. Utilizing synthetic peptides, we next defined heparin-binding site of 20 amino acids from 31 to 50 of MDP1, which is responsible for the specific DNA-binding site of MDP1. MDP1 bound to A549 cells, and exogenous DNA and HA interfered with the interaction. The binding was also abolished by treatment of A549 cells with hyaluronidase, suggesting that HA participates in the MDP1-A549 cell interaction. Adherence of bacillus Calmette-Guerin ( BCG) and M. tuberculosis to A549 cells was inhibited by addition of HA, DNA, and anti-MDP1 antibody, showing that MDP1 participates in the interaction between mycobacteria-alveolar epithelial cells. Simultaneous treatment of intratracheal BCG-infected mice with HA reduced the growth of BCG in vivo. Taken together, theses results suggest that HA participates in Mycobacterium-lung epithelium interaction and has potential for therapeutic and prophylactic interventions in mycobacterial infection.

DOI： 10.1074/jbc.M402677200

Web of Science

PubMed

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：SPRINGER-VERLAG  

Granulomatous colitis is a major entity of human intestinal diseases. We previously reported that intravenous injection of mycobacterial cord factor (CF), a potent macrophage activator, induced pulmonary granulomas in mice with enhanced production of Th1 cytokines and chemokines. In this study we made a murine model of granulomatous colitis by intramural injection of CF. A single dose of 300 mug CF was injected into the wall of the rat and mouse colon in the form of liposomes. After 1 week granulomas developed at the injection site, extending from the subserosa to the lamina propria, and persisted for longer than 6 weeks. They were composed mainly of ED1-positive macrophages, which often underwent apoptosis, and CD4(+) and CD8(+) lymphocytes, which preferentially infiltrated around the macrophage accumulation. Myofibroblast proliferation was not prominent, and no appreciable fibrosis resulted after the decline of granulomas. Although the intestinal epithelium was involved in inflammation, tissue injuries such as mucosal erosion or ulceration were not induced. When granulomas were formed near the Peyer's patches, they invaded deeply into the lymphoid tissue, producing many small islands. The mesenteric lymph nodes also had many granulomatous islands in the cortex and medulla, but the liver and spleen displayed no granulomatous changes, suggesting that liposomal CF spreads via the lymphatic vessels from the injection site. The CF-induced colonic granulomas associated with mesenteric lymphadenitis will be useful for investigating human granulomatous colitis.

DOI： 10.1007/s00428-002-0698-6

Web of Science

researchmap

記述言語：英語   出版者・発行元：SPRINGER-VERLAG  

Granulomatous colitis is a major entity of human intestinal diseases. We previously reported that intravenous injection of mycobacterial cord factor (CF), a potent macrophage activator, induced pulmonary granulomas in mice with enhanced production of Th1 cytokines and chemokines. In this study we made a murine model of granulomatous colitis by intramural injection of CF. A single dose of 300 mug CF was injected into the wall of the rat and mouse colon in the form of liposomes. After 1 week granulomas developed at the injection site, extending from the subserosa to the lamina propria, and persisted for longer than 6 weeks. They were composed mainly of ED1-positive macrophages, which often underwent apoptosis, and CD4(+) and CD8(+) lymphocytes, which preferentially infiltrated around the macrophage accumulation. Myofibroblast proliferation was not prominent, and no appreciable fibrosis resulted after the decline of granulomas. Although the intestinal epithelium was involved in inflammation, tissue injuries such as mucosal erosion or ulceration were not induced. When granulomas were formed near the Peyer's patches, they invaded deeply into the lymphoid tissue, producing many small islands. The mesenteric lymph nodes also had many granulomatous islands in the cortex and medulla, but the liver and spleen displayed no granulomatous changes, suggesting that liposomal CF spreads via the lymphatic vessels from the injection site. The CF-induced colonic granulomas associated with mesenteric lymphadenitis will be useful for investigating human granulomatous colitis.

DOI： 10.1007/s00428-002-0698-6

Web of Science

researchmap

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD  

Novel mycoloyl glycolipids with short carbon chains were isolated and purified from Rhodococcus sp. 4306, a soil origin of Actinomycetales. Their chemical structures were identified as trehalose 6,6'-dimycolate (TDM), trehalose 6-monomycolate, glucose 6-monomycolate, mannose 6-monomycolate and fructose 8-monomycolate. The length of carbon chains and number of double bonds Of mycolic acids were C-34, C-36 and C-38 saturated, monoenoic and dienoic molecular species, which were much shorter than those of Mycobacterium tuberculosis (C78-88 monoenoic and dienoic). Among them, only. TDM could induce prominent granulomatous inflammation of the lung and spleen in mice. By contrast, other mycoloyl glycolipids induced mild lesions. The small-sized TDM of Rhodococcus possessed granulomatogenic activity, however, the toxicity was much lower than that of M. tuberculosis. Rhodococcal TDM was composed; of mycolic acid with the shortest carbon chains, when compared to granulomatogenic TDM of Mycobacterium, Nocardia and Rhodococcus reported previously. Our results imply that rhodococcal TDM is a pathogenetic factor similar to that of M. tuberculosis, although rhodococcal TDM exhibits low toxicity. (C) 2001 Academic Press.

DOI： 10.1006/mpat.2000.0413

Web of Science

researchmap

記述言語：英語   出版者・発行元：ACADEMIC PRESS LTD  

Novel mycoloyl glycolipids with short carbon chains were isolated and purified from Rhodococcus sp. 4306, a soil origin of Actinomycetales. Their chemical structures were identified as trehalose 6,6'-dimycolate (TDM), trehalose 6-monomycolate, glucose 6-monomycolate, mannose 6-monomycolate and fructose 8-monomycolate. The length of carbon chains and number of double bonds Of mycolic acids were C-34, C-36 and C-38 saturated, monoenoic and dienoic molecular species, which were much shorter than those of Mycobacterium tuberculosis (C78-88 monoenoic and dienoic). Among them, only. TDM could induce prominent granulomatous inflammation of the lung and spleen in mice. By contrast, other mycoloyl glycolipids induced mild lesions. The small-sized TDM of Rhodococcus possessed granulomatogenic activity, however, the toxicity was much lower than that of M. tuberculosis. Rhodococcal TDM was composed; of mycolic acid with the shortest carbon chains, when compared to granulomatogenic TDM of Mycobacterium, Nocardia and Rhodococcus reported previously. Our results imply that rhodococcal TDM is a pathogenetic factor similar to that of M. tuberculosis, although rhodococcal TDM exhibits low toxicity. (C) 2001 Academic Press.

DOI： 10.1006/mpat.2000.0413

Web of Science

researchmap

記述言語：英語  

The effects of a 47-week diet of butter or safflower oil as fat in combination with casein or soy protein as protein were observed for the serum concentrations of lipids and fatty acid compositions in rat serum and heart. Serum total cholesterol (Chol) did not difffer among the four experimental diet groups. In the butter groups, significantly higher low-density lipoprotein (LDL)-Chol and lower high-density lipoprotein (HDL)-Chol were observed than in the safflower oil groups (p&lt
0.005, respectively). Higher levels of α-tocopherol were found in the butter groups than in the safflower oil groups (p&lt
0.05) and in the casein groups than in the soy protein groups (p&lt
0.01). In comparison with the safflower oil groups, the butter groups showed higher n-3 polyunsaturated fatty acids (PUFA) contents and lower n-6 PUFA contents in serum and the hearts (p&lt
0.005). The ratios of n-3/n-6 PUFA in the butter groups in serum, 0.26 and 0.18, and in the hearts, 0.37 and 0.36, (butter-casein diet and butter-soy protein diet, respectively) were higher than those of the safflower oil groups of under 0.01 in serum and 0.02 and 0.03 in the hearts (safflower oil-casein diet and safflower oil-soy protein diet, respectively) (p&lt
0.005). In the soy protein groups, higher n-3 PUFA contents in the hearts were found than those of the casein groups (p&lt
0.05). This study suggested that the butter diet induces higher levels of n-3 PUFA and a higher n-3/n-6 PUFA ratio than the safflower oil diet in rat serum and hearts over a long feeding period.

DOI： 10.1265/ehpm.2000.138

Scopus

CiNii Article

researchmap

記述言語：英語  

The effects of a 47-week diet of butter or safflower oil as fat in combination with casein or soy protein as protein were observed for the serum concentrations of lipids and fatty acid compositions in rat serum and heart. Serum total cholesterol (Chol) did not difffer among the four experimental diet groups. In the butter groups, significantly higher low-density lipoprotein (LDL)-Chol and lower high-density lipoprotein (HDL)-Chol were observed than in the safflower oil groups (p&lt
0.005, respectively). Higher levels of α-tocopherol were found in the butter groups than in the safflower oil groups (p&lt
0.05) and in the casein groups than in the soy protein groups (p&lt
0.01). In comparison with the safflower oil groups, the butter groups showed higher n-3 polyunsaturated fatty acids (PUFA) contents and lower n-6 PUFA contents in serum and the hearts (p&lt
0.005). The ratios of n-3/n-6 PUFA in the butter groups in serum, 0.26 and 0.18, and in the hearts, 0.37 and 0.36, (butter-casein diet and butter-soy protein diet, respectively) were higher than those of the safflower oil groups of under 0.01 in serum and 0.02 and 0.03 in the hearts (safflower oil-casein diet and safflower oil-soy protein diet, respectively) (p&lt
0.005). In the soy protein groups, higher n-3 PUFA contents in the hearts were found than those of the casein groups (p&lt
0.05). This study suggested that the butter diet induces higher levels of n-3 PUFA and a higher n-3/n-6 PUFA ratio than the safflower oil diet in rat serum and hearts over a long feeding period.

DOI： 10.1265/ehpm.2000.138

Scopus

CiNii Article

researchmap

記述言語：日本語  

CiNii Article

CiNii Books

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：AMER SOC MICROBIOLOGY  

It is reported that some bacteria or bacterial components cause thymic atrophy via the apoptotic process, The present study demonstrated for the first time in vivo induction of apoptosis in the mouse thymus by mycobacterial cord factor (CF) (trehalose 6,6'-dimycolate). When 300 mu g of purified CF from Mycobacterium tuberculosis was intravenously administered to BALB/c mice in the form of water-in-oil-in-water (w/o/w) emulsion, thymic atrophy and pulmonary granulomas were induced with a peak on day 7, whereas, in the form of liposomes, CP induced thymic atrophy on days 14 to 21 in parallel with the development of hepatic granulomas. Thymic atrophy resulted from the depletion of cortical lymphocytes via apoptosis as revealed by DNA fragmentation and karyorrhectic changes, In contrast, mycobacterial sulfatide (2,3,6,6'-tetraacyl trehalose 2'-sulfate) caused neither thymic atrophy nor granuloma formation, Compared to lipopolysaccharide-induced thymocyte apoptosis, CF (w/o/w)-induced thymocyte apoptosis developed more slowly, reached a maximum later, and lasted longer but was less intense. Although serum tumor necrosis factor alpha (TNF-alpha) levels in CF-treated mice were not significantly elevated, administration of anti-TNF-alpha antibody almost completely inhibited thymic atrophy and granuloma formation, Serum corticosterone levels were only slightly elevated by CF administration. The present results indicate that mycobacterial CF induces thymic atrophy via apoptosis, which is closely linked with granuloma formation.

Web of Science

researchmap

記述言語：英語   出版者・発行元：AMER SOC MICROBIOLOGY  

It is reported that some bacteria or bacterial components cause thymic atrophy via the apoptotic process, The present study demonstrated for the first time in vivo induction of apoptosis in the mouse thymus by mycobacterial cord factor (CF) (trehalose 6,6'-dimycolate). When 300 mu g of purified CF from Mycobacterium tuberculosis was intravenously administered to BALB/c mice in the form of water-in-oil-in-water (w/o/w) emulsion, thymic atrophy and pulmonary granulomas were induced with a peak on day 7, whereas, in the form of liposomes, CP induced thymic atrophy on days 14 to 21 in parallel with the development of hepatic granulomas. Thymic atrophy resulted from the depletion of cortical lymphocytes via apoptosis as revealed by DNA fragmentation and karyorrhectic changes, In contrast, mycobacterial sulfatide (2,3,6,6'-tetraacyl trehalose 2'-sulfate) caused neither thymic atrophy nor granuloma formation, Compared to lipopolysaccharide-induced thymocyte apoptosis, CF (w/o/w)-induced thymocyte apoptosis developed more slowly, reached a maximum later, and lasted longer but was less intense. Although serum tumor necrosis factor alpha (TNF-alpha) levels in CF-treated mice were not significantly elevated, administration of anti-TNF-alpha antibody almost completely inhibited thymic atrophy and granuloma formation, Serum corticosterone levels were only slightly elevated by CF administration. The present results indicate that mycobacterial CF induces thymic atrophy via apoptosis, which is closely linked with granuloma formation.

Web of Science

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

DOI： 10.5264/eiyogakuzashi.51.81

CiNii Article

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：日本語  

J-GLOBAL

researchmap

記述言語：英語   出版者・発行元：CENTER ACADEMIC PUBL JAPAN  

DOI： 10.3177/jnsv.32.363

Web of Science

PubMed

CiNii Article

researchmap

記述言語：英語   出版者・発行元：CENTER ACADEMIC PUBL JAPAN  

DOI： 10.3177/jnsv.32.363

Web of Science

PubMed

CiNii Article

researchmap

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

researchmap

researchmap

会議種別：ポスター発表  

researchmap

会議種別：ポスター発表  

researchmap

researchmap

researchmap

会議種別：ポスター発表  

researchmap

researchmap

researchmap

会議種別：ポスター発表  

researchmap

researchmap

researchmap

会議種別：ポスター発表  

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap