Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adjuvant arthritis (AA) is induced by immunizing Lewis rats with Mycobacterium tuberculosis suspended in adjuvant. The mycobacterial 65-kDa heat shock protein (HSP65) contains at least one epitope associated with the pathogenesis of AA: T cell clones that recognize an epitope formed by aa 180-188 of HSP65 react with self-cartilage and can adoptively transfer AA. Nevertheless, vaccination with HSP65 or some of its T cell epitopes can prevent AA by a mechanism that seems to involve cross-reactivity with the self-60-kDa HSP60. We recently demonstrated that DNA vaccination with the human hsp60 gene can inhibit AA. In the present work, we searched for regulatory epitopes using DNA vaccination with HSP60 gene fragments. We now report that specific HSP60 DNA fragments can serve as effective vaccines. Using overlapping HSP60 peptides, we identified a regulatory peptide (Hu3) that was specifically recognized by the T cells of DNA-vaccinated rats. Vaccination with Hu3, or transfer of splenocytes from Hu3-vaccinated rats, inhibited the development of AA. Vaccination with the mycobacterial homologue of Hu3 had no effect. Effective DNA or peptide vaccination was associated with enhanced T cell proliferation to a variety of disease-associated Ags, along with a Th2/3-like shift (down-regulation of IFN-gamma secretion and enhanced secretion of IL-10 and/or tumor growth factor beta1) in response to peptide Mt176-190 (the 180-188 epitope of HSP65). The regulatory response to HSP60 or its Hu3 epitope included both Th1 (IFN-gamma) and Th2/3 (IL-10/tumor growth factor beta1) secretors. These results show that regulatory mechanisms can be activated by immunization with relevant self-HSP60 epitopes.
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PMID:DNA fragments of the human 60-kDa heat shock protein (HSP60) vaccinate against adjuvant arthritis: identification of a regulatory HSP60 peptide. 1450 Jun 49

A single sub-cutaneous injection of a plasmid DNA encoding a mycobacterial heat shock protein 65 (Hsp65) entrapped in biodegradable poly(lactic-co-glycolic acid) microspheres produced high titers of antibodies, measured 5 months after the injection in BALB/c mice. Splenocytes secreted IFN-gamma and exerted an anti-bacterial effect on macrophages infected in vitro with Mycobacterium tuberculosis. The results are encouraging with regard to obtaining good compliance and vaccination coverage with candidate plasmid DNA vaccines, especially in developing countries.
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PMID:Anti-mycobacterial immunity induced by a single injection of M. leprae Hsp65-encoding plasmid DNA in biodegradable microparticles. 1468 8

Analysis of heat shock protein 65 (hsp65) gene restriction fragment length polymorphism (RFLP) is done frequently to identify non-tuberculous mycobacteria (NTM) on a genetic basis. Here we report the results of analysing the hsp65 patterns of some rarely isolated NTM for which patterns have not been published before (Mycobacterium bohemicum, Mycobacterium hassiacum, Mycobacterium heckeshornense, Mycobacterium monacense, and Mycobacterium triplex). Furthermore new hsp65-variants for Mycobacterium interjectum (type II), Mycobacterium mucogenicum (type V), Mycobacterium gordonae (type VIII) and Mycobacterium paraffinicum (perhaps synonymous to Mycobacterium scrofulaceum) are described. All species were characterised by hsp65-RFLP, sequencing a 441-bp fragment of the hsp65 gene and sequencing the hypervariable region of the 16S rDNA. Additional data for less frequently isolated mycobacteria are provided and the hitherto described data for the Mycobacterium gordonae complex are summarised. Although the hsp65-RFLP analysis turned out to be a useful method a number of restraints (lack of standardisation, slight variability in fragment length) limits its broader use. Reliable identification of NTM needs, however, more than one molecular method. Identification results obtained by applying different methods yielded conflicting results. Confusion may be caused by older data base entries which are not updated and not longer reflect the actual systematic and taxonomy of the genus Mycobacterium.
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PMID:Different molecular methods for the identification of rarely isolated non-tuberculous mycobacteria and description of new hsp65 restriction fragment length polymorphism patterns. 1503 71

The heat shock protein 65 kDa (Hsp65) of Mycobacterium tuberculosis var. bovis was fused with the linear polypeptide epitope of cholesteryl ester transfer protein C-terminal fragment (CETPC) and expressed as soluble protein in Escherichia coli. The fusion protein Hsp65-CETPC was purified by anion exchange column and eluted at 100-130 mM NaCl in 10mM phosphate buffer (pH 8.0), and then used to immunize mice via subcutaneous injection or intranasal delivery in the absence of adjuvants. Antibodies against CETPC were detected in immunized mice sera by enzyme-linked immunosorbent assay (ELISA) and verified by Western blot analysis. Specific antibodies were successfully induced and lasted for more than 12 weeks in animals immunized with the fusion protein via both subcutaneous and intranasal routes even in the absence of adjuvants. Results showed that Hsp65 could be used as a convenient carrier molecule for presenting foreign polypeptide epitopes, such as CETPC, to the immune system in vivo. Antibodies induced by Hsp65-CETPC could partially inhibit the excessive activity of CETP to normal level. Therefore, Hsp65-CETPC might be further developed to a vaccine against atherosclerosis.
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PMID:Long-lasting specific antibodies against CETP induced by subcutaneous and mucosal administration of a 26-amino acid CETP epitope carried by heat shock protein 65 kDa in the absence of adjuvants. 1529 73

In order to cope with the worldwide increase in the prevalence of multidrug-resistant tuberculosis and Mycobacterium avium complex (MAC) infections, a number of new antimycobacterial drugs have been or are being synthesized and developed. Development of new protocols for chemotherapy of refractory mycobacterioses is also sharing promise. In this context, one promising strategy is to devise regimens to treat patients with refractory mycobacterioses using ordinary antimycobacterial agents in combination with appropriate immunomodulators. This article deals with the following matters: an outline of the host immune response to mycobacterial pathogens, particularly in terms of mobilization of the cytokine network in response to mycobacterial infection, and adjunctive immunotherapy using (1) recombinant immunomodulating cytokines, (especially Th-1 and Th-1-like cytokines such as IFN-gamma, IL-2, IL-12, IL-18 and GM-CSF), (2) inhibitors of immunosuppressive cytokines (TGF-beta) and some proinflammatory tissue-damaging cytokines (TNF-alpha), and (3) immunomodulatory agents such as ATP and its analogs, imidazoquinoline, diethyldithiocarbamate, poloxamer, dibenzopyran, galactosylceramide, nonsteroidal anti-inflammatory drugs, Chinese traditional medicines, levamisole, synthesized mycobacterial oligoDNA, DNA vaccine expressing mycobacterial HSP65 or IL-12, and heat-killed Mycobacterium vaccae. Although adjunctive immunotherapy is fairly efficacious in treating intractable mycobacterioses, it still features serious problems and dilemmas, such as high cost, occasionally severe side effects, and, in many cases, only modest efficacy in potentiating host defense mechanisms against mycobacterial infections, primarily because of the induction of macrophage-deactivating cytokines during the course of long-term administration of adjunctive agents.
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PMID:Adjunctive immunotherapy of mycobacterial infections. 1554 17

Immunotherapy based on the administration of the mycobacterium bacillus Calmette-Guerin has been successfully used in the treatment of in situ transitional cell bladder cancer, and may be applicable to the treatment of cutaneous malignant melanoma. Antigen 85A (Ag85A) and heat shock protein 65 kDa (hsp65) are major secreted proteins of Mycobacterium species and potent stimulators of cell-mediated immunity. This study evaluated the ability of Ag85A and hsp65 gene transfection to limit tumor growth by B16-F10 mouse melanoma cells. Immunoblotting confirmed protein expression and secretion by B16-F10 cells that were transiently transfected with plasmid DNA containing the Ag85A or hsp65 gene. Groups of syngeneic C57BL/6 mice were injected subcutaneously with 1x10(5) untransfected B16-F10 cells or B16-F10 cells transiently transfected with either empty vector or vector containing the Ag85A or hsp65 gene. Ag85A-expressing B16-F10 cells exhibited a dramatic 76% reduction (p<0.05, Mann-Whitney U test) in tumor weight in comparison to empty vector controls at 14 days post-inoculation. In contrast, hsp65-transfected B16-F10 cells did not show any change in tumorigenicity. Decreased tumorigenicity by Ag85A-transfected B16-F10 cells was not due to a reduced ability of Ag85A-transfected B16-F10 cells to proliferate since both mock- and Ag85A-transfected B16-F10 cells showed increased in vitro proliferation in comparison to untransfected cells. Hematoxylin and eosin staining revealed that Ag85A-transfected B16-F10 tumors contained an inflammatory leukocyte infiltrate that was not present in hsp65-transfected tumors. Reduced tumor progression by Ag85A-transfected B16-F10 melanoma cells suggests that immunotherapy based on the transient induction of Ag85A expression may be an effective approach for the treatment of cutaneous malignant melanoma.
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PMID:Reduced tumorigenicity of B16-F10 mouse melanoma cells transfected with mycobacterial antigen 85A. 1554 7

The purpose of this study was to express the HSP65 gene of Mycobacterium tuberculosis in eukaryotic cells and study its primary immune effect in animals. The HSP65 gene was amplified from the H37Rv strain of M. tuberculosis by PCR and then inserted into the expression plasmid pcDNA3.1(-). The recombinant plasmid pcHSP65 was transfected into HeLa cells by using the liposome transfection method and also injected into BALB/C mice to accomplish DNA immunization. The inserted gene was demonstrated to be identical to the reported HSP65 gene sequence. The transfected HeLa cells expressed HSP65 protein; Western blot showed the presence of a 65 kDa band of the inclusion body protein and immunofluorescence testing identified the protein expressed in cytoplasm. Specific IgG for the HSP65 protein could be identified in immunized mice. This study shows that recombinant eukaryotic expression plasmid pcHSP65 was constructed successfully, which lays a foundation for further study of gene therapy.
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PMID:Construction of a eukaryotic expression system of HSP65 gene from Mycobacterium tuberculosis, and anti-HSP65 IgG produced in mice. 1559 Dec 48

Polymerase chain reaction (PCR) amplification of the heat shock protein 65 (hsp65) gene followed by high-resolution melting analysis with LCGreen I (Idaho Technology, Salt Lake City, UT) was used to differentiate the mycobacteria species Mycobacterium chelonae, Mycobacterium abscessus, and Mycobacterium immunogenum in less than 20 minutes. A 105-base-pair amplicon that clustered the different species by predicted melting temperature was found from available GenBank hsp65 sequences. We identified 24 clinical isolates within the M chelonae-abscessus group by proximal 16S ribosomal RNA and hsp65 gene sequencing. Rapid-cycle PCR followed by high-resolution melting analysis clustered these samples into the following groups: M abscessus, 12; M abscessus sequence variant, 2; M chelonae, 7; unexpected M chelonae sequence variant, 1; and M immunogenum, 2. The M chelonae variant had a single base change not found in reported GenBank sequences. Advantages of the method include speed, low risk of amplicon contamination (closed-tube), and no need for separation steps (sequencing, electrophoresis, high-performance liquid chromatography) or real-time monitoring.
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PMID:Rapid species identification within the Mycobacterium chelonae-abscessus group by high-resolution melting analysis of hsp65 PCR products. 1576 84

The increasing incidence of tuberculosis and other mycobacterial infections due to AIDS epidemic resulted in the need of rapid and accurate identification of isolated mycobacteria. The correct identification result leads to the selection of an appropriate therapeutic regimen. Polymerase chain reaction and restriction enzyme analysis (PCR-REA) has been developed since 1992 and used as the rapid method for identifying mycobacteria. Several genes or sequences have been used as an amplified target for PCR-REA. The present study aims to evaluate the potential use of PCR-REA of gene-encoding heat shock protein 65 kDa (hsp65) and beta-subunit RNA polymerase (rpoB) for the identification of mycobacteria compared with conventional biochemical identification. Two hundreds clinical isolates, consisting of 50 isolates of Mycobacterium tuberculosis and 150 isolates of nontuberculous mycobacteria (NTM), were submitted for identification using PCR-REA and biochemical method. The results demonstrated that PCR-REA identified 188 isolates of both M. tuberculosis and NTM concordantly with biochemical identification. Discordant identification results obtained from 12 isolates, comprised of 8 M. scrofulaceum, 1 M. avium complex, 1 M. malmoense, 1 M. terrae complex, and 1 M. chelonae/abscessus. Overall, the concordant percentage of results obtained from PCR-REA compared with biochemical method was 100%, 98.8%, and 83.3% for M. tuberculosis complex, rapidly growing, and slowly growing mycobacteria, respectively, and the results of hsp65 PCR-REA was in agreement with those obtained from rpoB PCR-REA. From this study, PCR-REA appears to be a simple, rapid, and reliable method for identifying mycobacteria in a routine microbiology laboratory.
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PMID:Comparative evaluation of polymerase chain reaction and restriction enzyme analysis: two amplified targets, hsp65 and rpoB, for identification of cultured mycobacteria. 1576 1

Although the Toll-like receptors used by Mycobacterium tuberculosis membrane and secreted factors are known, the pathways activated by M. tuberculosis heat shock proteins are not. An efficient immune response against the intracellular pathogen M. tuberculosis is critically dependent on rapid detection of the invading pathogen by the innate immune system and coordinated activation of the adaptive immune response. Macrophage phagocytosis of M. tuberculosis is accompanied by activation of the transcription factor NF-kappaB and secretion of inflammatory mediators that play an important role in granuloma formation and immune protection during M. tuberculosis infection. The interaction between M. tuberculosis and the various Toll-like receptors is complex, and it appears that distinct mycobacterial components may interact with different members of the Toll-like receptor family. Here we show that recombinant, purified, mycobacterial heat shock proteins 65 and 70 induce NF-kappaB activity in a dose-dependent manner in human endothelial cells. Furthermore, we show that whereas mycobacterial heat shock protein 65 signals exclusively through Toll-like receptor 4, heat shock protein 70 also signals through Toll-like receptor 2. Mycobacterial heat shock protein 65-induced NF-kappaB activation was MyD88-, TIRAP-, TRIF-, and TRAM-dependent and required the presence of MD-2. A better understanding of the recognition of mycobacterial heat shock proteins and their role in the host immune response to the pathogen may open the way to a better understanding of the immunological processes induced by this important human pathogen and the host-pathogen interactions and may help in the rational design of more effective vaccines or vaccine adjuvants.
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PMID:Mycobacterium tuberculosis heat shock proteins use diverse Toll-like receptor pathways to activate pro-inflammatory signals. 1580 3


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