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2.
PLoS Negl Trop Dis ; 15(12): e0010018, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34914694

RESUMO

T cell receptors (TCRs) encode the history of antigenic challenge within an individual and have the potential to serve as molecular markers of infection. In addition to peptide antigens bound to highly polymorphic MHC molecules, T cells have also evolved to recognize bacterial lipids when bound to non-polymorphic CD1 molecules. One such subset, germline-encoded, mycolyl lipid-reactive (GEM) T cells, recognizes mycobacterial cell wall lipids and expresses a conserved TCR-ɑ chain that is shared among genetically unrelated individuals. We developed a quantitative PCR assay to determine expression of the GEM TCR-ɑ nucleotide sequence in human tissues and blood. This assay was validated on plasmids and T cell lines. We tested blood samples from South African subjects with or without tuberculin reactivity or with active tuberculosis disease. We were able to detect GEM TCR-ɑ above the limit of detection in 92% of donors but found no difference in GEM TCR-ɑ expression among the three groups after normalizing for total TCR-ɑ expression. In a cohort of leprosy patients from Nepal, we successfully detected GEM TCR-ɑ in 100% of skin biopsies with histologically confirmed tuberculoid and lepromatous leprosy. Thus, GEM T cells constitute part of the T cell repertoire in the skin. However, GEM TCR-ɑ expression was not different between leprosy patients and control subjects after normalization. Further, these results reveal the feasibility of developing a simple, field deployable molecular diagnostic based on mycobacterial lipid antigen-specific TCR sequences that are readily detectable in human tissues and blood independent of genetic background.


Assuntos
Hanseníase/diagnóstico , Lipídeos/imunologia , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Tuberculose/diagnóstico , Antígenos CD1/genética , Antígenos CD1/imunologia , Parede Celular/genética , Parede Celular/imunologia , Estudos de Coortes , Humanos , Hanseníase/sangue , Hanseníase/imunologia , Hanseníase/microbiologia , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Nepal , Reação em Cadeia da Polimerase , Receptores de Antígenos de Linfócitos T alfa-beta/sangue , Receptores de Antígenos de Linfócitos T alfa-beta/genética , África do Sul , Linfócitos T/imunologia , Linfócitos T/microbiologia , Tuberculose/sangue , Tuberculose/imunologia , Tuberculose/microbiologia
3.
Front Immunol ; 12: 747387, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630426

RESUMO

Mycobacterial diseases are a major public health challenge. Their causative agents include, in order of impact, members of the Mycobacterium tuberculosis complex (causing tuberculosis), Mycobacterium leprae (causing leprosy), and non-tuberculous mycobacterial pathogens including Mycobacterium ulcerans. Macrophages are mycobacterial targets and they play an essential role in the host immune response to mycobacteria. This review aims to provide a comprehensive understanding of the immune-metabolic adaptations of the macrophage to mycobacterial infections. This metabolic rewiring involves changes in glycolysis and oxidative metabolism, as well as in the use of fatty acids and that of metals such as iron, zinc and copper. The macrophage metabolic adaptations result in changes in intracellular metabolites, which can post-translationally modify proteins including histones, with potential for shaping the epigenetic landscape. This review will also cover how critical tuberculosis co-morbidities such as smoking, diabetes and HIV infection shape host metabolic responses and impact disease outcome. Finally, we will explore how the immune-metabolic knowledge gained in the last decades can be harnessed towards the design of novel diagnostic and therapeutic tools, as well as vaccines.


Assuntos
Adaptação Fisiológica/imunologia , Interações Hospedeiro-Patógeno/imunologia , Macrófagos/imunologia , Infecções por Mycobacterium/imunologia , Animais , Humanos , Macrófagos/metabolismo , Mycobacterium/imunologia , Infecções por Mycobacterium/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-34379957

RESUMO

BACKGROUND: Contacts of leprosy patients have an increased risk of infection with Mycobacterium leprae. Contact tracing and chemo- or immunoprophylaxis are important means of preventing leprosy transmission. AIMS: We aimed to evaluate the efficacy of immunoprophylaxis with Mycobacterium indicus pranii vaccine in reducing anti-phenolic glycolipid-1 titers in household contacts of leprosy patients. METHODS: This prospective single-center study was conducted in a tertiary care center in North India from January 2015 to December 2016. Contacts of leprosy patients (both paucibacillary and multibacillary) were screened for anti-phenolic glycolipid-1 antibodies with enzyme-linked immunosorbent assay. Those found positive were given immunoprophylaxis with a single dose of Mycobacterium indicus pranii vaccine, and anti-phenolic glycolipid-1 titers were evaluated at six and 12 months. All contacts were clinically followed for three years. RESULTS: Of the 135 contacts of 98 leprosy patients that were screened, 128 were recruited. Seventeen of these contacts were positive for anti-phenolic glycolipid-1 antibodies and were given Mycobacterium indicus pranii vaccine. Two contacts were lost to follow-up. After immunoprophylaxis, anti-phenolic glycolipid-1 titers were negative in all patients at all intervals, and no contact developed any clinical signs or symptoms of leprosy during the three-year follow-up. LIMITATIONS: The small number of contacts studied, the short follow-up period and the absence of a control group were limitations of this study. Dicussion: We could not find any papers on natural decline of PGL 1 titres in contacts, although in leprosy patients, these titres may even increase after completion of treatment. However the titres do correlate with bacterial load (reference: Int J Lepr Other Mycobact Dis. 1998 Sep;66(3):356-64) so if the tires decrease or become negative it may be considered as an indirect evidence of bacillary clearance. Hence we may suggest the protective efficacy. Furthermore, as the editor mentioned, considering the small number of positive patients, a control group was not possible in the present pilot study, but such studies may be carried out in the future. CONCLUSION: Immunoprophylaxis with Mycobacterium indicus pranii vaccine is effective and safe in preventing disease in contacts of leprosy patients. However, these findings need to be replicated in larger studies.


Assuntos
Anticorpos Antibacterianos/sangue , Vacinas Bacterianas , Glicolipídeos/imunologia , Hanseníase/imunologia , Mycobacterium/imunologia , Adulto , Busca de Comunicante , Feminino , Humanos , Hanseníase/transmissão , Masculino , Projetos Piloto , Estudos Prospectivos , Centros de Atenção Terciária
5.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299217

RESUMO

The mycobacterial cell wall is composed of large amounts of lipids with varying moieties. Some mycobacteria species hijack host cells and promote lipid droplet accumulation to build the cellular environment essential for their intracellular survival. Thus, lipids are thought to be important for mycobacteria survival as well as for the invasion, parasitization, and proliferation within host cells. However, their physiological roles have not been fully elucidated. Recent studies have revealed that mycobacteria modulate the peroxisome proliferator-activated receptor (PPAR) signaling and utilize host-derived triacylglycerol (TAG) and cholesterol as both nutrient sources and evasion from the host immune system. In this review, we discuss recent findings that describe the activation of PPARs by mycobacterial infections and their role in determining the fate of bacilli by inducing lipid metabolism, anti-inflammatory function, and autophagy.


Assuntos
Infecções por Mycobacterium/microbiologia , Mycobacterium/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Animais , Autofagia/fisiologia , Colesterol/metabolismo , Humanos , Metabolismo dos Lipídeos , Mycobacterium/crescimento & desenvolvimento , Mycobacterium/imunologia , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/genética , Transdução de Sinais
6.
mSphere ; 6(3)2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33952660

RESUMO

Mycobacterium tuberculosis infections claim more than a million lives each year, and better treatments or vaccines are required. A crucial pathogenicity factor is translocation from phagolysosomes to the cytosol upon phagocytosis by macrophages. Translocation from the phagolysosome to the cytosol is an ESX-1-dependent process, as previously shown in vitro Here, we show that in vivo, mycobacteria also translocate to the cytosol but mainly when host immunity is compromised. We observed only low numbers of cytosolic bacilli in mice, armadillos, zebrafish, and patient material infected with M. tuberculosis, M. marinum, or M. leprae In contrast, when innate or adaptive immunity was compromised, as in severe combined immunodeficiency (SCID) or interleukin-1 receptor 1 (IL-1R1)-deficient mice, significant numbers of cytosolic M. tuberculosis bacilli were detected in the lungs of infected mice. Taken together, in vivo, translocation to the cytosol of M. tuberculosis is controlled by adaptive immune responses as well as IL-1R1-mediated signals.IMPORTANCE For decades, Mycobacterium tuberculosis has been one of the deadliest pathogens known. Despite infecting approximately one-third of the human population, no effective treatment or vaccine is available. A crucial pathogenicity factor is subcellular localization, as M. tuberculosis can translocate from phagolysosome to the cytosol in macrophages. The situation in vivo is more complicated. In this study, we establish that high-level cytosolic escape of mycobacteria can indeed occur in vivo but mainly when host resistance is compromised. The IL-1 pathway is crucial for the control of the number of cytosolic mycobacteria. The establishment that immune signals result in the clearance of cells containing cytosolic mycobacteria connects two important fields, cell biology and immunology, which is vital for the understanding of the pathology of M. tuberculosis.


Assuntos
Citosol/microbiologia , Mycobacterium/imunologia , Mycobacterium/patogenicidade , Fagossomos/microbiologia , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/imunologia , Transdução de Sinais/imunologia , Animais , Tatus/microbiologia , Translocação Bacteriana , Citosol/imunologia , Feminino , Humanos , Hanseníase/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Mycobacterium/classificação , Fagossomos/imunologia , Pele/microbiologia , Pele/patologia , Células THP-1 , Peixe-Zebra
7.
Front Immunol ; 12: 782495, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003097

RESUMO

The mycobacterium genus contains a broad range of species, including the human pathogens M. tuberculosis and M. leprae. These bacteria are best known for their residence inside host cells. Neutrophils are frequently observed at sites of mycobacterial infection, but their role in clearance is not well understood. In this review, we discuss how neutrophils attempt to control mycobacterial infections, either through the ingestion of bacteria into intracellular phagosomes, or the release of neutrophil extracellular traps (NETs). Despite their powerful antimicrobial activity, including the production of reactive oxidants such as hypochlorous acid, neutrophils appear ineffective in killing pathogenic mycobacteria. We explore mycobacterial resistance mechanisms, and how thwarting neutrophil action exacerbates disease pathology. A better understanding of how mycobacteria protect themselves from neutrophils will aid the development of novel strategies that facilitate bacterial clearance and limit host tissue damage.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/microbiologia , Mycobacterium/imunologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Animais , Biomarcadores , Citotoxicidade Imunológica , Suscetibilidade a Doenças/imunologia , Armadilhas Extracelulares/genética , Armadilhas Extracelulares/imunologia , Interações Hospedeiro-Patógeno/genética , Humanos , Imunidade Inata , Infecções por Mycobacterium/diagnóstico , Infecções por Mycobacterium/metabolismo , Ativação de Neutrófilo/genética , Ativação de Neutrófilo/imunologia , Neutrófilos/microbiologia , Neutrófilos/patologia , Oxidantes/metabolismo , Estresse Oxidativo , Fagocitose/genética , Fagocitose/imunologia , Fagossomos/metabolismo
11.
PLoS Negl Trop Dis ; 10(5): e0004701, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27192147

RESUMO

Epidemiological differences exist between Mycobacterium africanum (Maf)- and Mycobacterium tuberculosis (Mtb)-infected patients, but to date, contributing host factors have not been characterised. We analysed clinical outcomes, as well as soluble markers and gene expression profiles in unstimulated, and ESAT6/CFP-10-, whole-Maf- and Mtb-stimulated blood samples of 26 Maf- and 49 Mtb-HIV-negative tuberculosis patients before, and after 2 and 6 months of anti-tuberculosis therapy. Before treatment, both groups had similar clinical parameters, but differed in few cytokines concentration and gene expression profiles. Following treatment the body mass index, skinfold thickness and chest X-ray scores showed greater improvement in the Mtb- compared to Maf-infected patients, after adjusting for age, sex and ethnicity (p = 0.02; 0.04 and 0.007, respectively). In addition, in unstimulated blood, IL-12p70, IL12A and TLR9 were significantly higher in Maf-infected patients, while IL-15, IL-8 and MIP-1α were higher in Mtb-infected patients. Overnight stimulation with ESAT-6/CFP-10 induced significantly higher levels of IFN-γ and TNF-α production, as well as gene expression of CCL4, IL1B and TLR4 in Mtb- compared to Maf-infected patients. Our study confirms differences in clinical features and immune genes expression and concentration of proteins associated with inflammatory processes between Mtb- and Maf-infected patients following anti-tuberculosis treatment These findings have public health implications for treatment regimens, and biomarkers for tuberculosis diagnosis and susceptibility.


Assuntos
Antituberculosos/uso terapêutico , Citocinas/sangue , Mycobacterium tuberculosis/imunologia , Mycobacterium/imunologia , Tuberculose/tratamento farmacológico , Tuberculose/imunologia , Adolescente , Adulto , Idoso , Antígenos de Bactérias/imunologia , Biomarcadores/sangue , Feminino , Gâmbia , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Interferon gama/sangue , Interleucina-5/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Mycobacterium/efeitos dos fármacos , Mycobacterium/isolamento & purificação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/etnologia , Tuberculose/microbiologia , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Adulto Jovem
12.
World J Gastroenterol ; 18(35): 4855-65, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23002357

RESUMO

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease characterized by the immune-mediated destruction of biliary epithelial cells in small intrahepatic bile ducts. The disease is characterized by circulating antimitochondrial antibodies (AMAs) as well as disease-specific antinuclear antibodies, cholestatic liver function tests, and characteristic histological features, including granulomas. A variety of organisms are involved in granuloma formation, of which mycobacteria are the most commonly associated. This has led to the hypothesis that mycobacteria may be involved in the pathogenesis of PBC, along with other infectious agents. Additionally, AMAs are found in a subgroup of patients with mycobacterial infections, such as leprosy and pulmonary tuberculosis. Antibodies against species-specific mycobacterial proteins have been reported in patients with PBC, but it is not clear whether these antibodies are specific for the disease. In addition, data in support of the involvement of the role of molecular mimicry between mycobacterial and human mitochondrial antigens as triggers of cross-reactive immune responses leading to the loss of immunological tolerance, and the induction of pathological features have been published. Thus, antibodies against mycobacterial heat shock protein appear to cross-recognize AMA-specific autoantigens, but it is not clear whether these autoantibodies are mycobacterium-species-specific, and whether they are pathogenic or incidental. The view that mycobacteria are infectious triggers of PBC is intriguing, but the data provided so far are not conclusive.


Assuntos
Cirrose Hepática Biliar/microbiologia , Infecções por Mycobacterium/microbiologia , Mycobacterium/patogenicidade , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Autoanticorpos/sangue , Reações Cruzadas , Granuloma/imunologia , Granuloma/microbiologia , Humanos , Cirrose Hepática Biliar/imunologia , Mitocôndrias/imunologia , Mimetismo Molecular , Mycobacterium/imunologia , Infecções por Mycobacterium/complicações , Infecções por Mycobacterium/imunologia , Fatores de Risco
13.
Vaccine ; 30(39): 5748-54, 2012 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-22796586

RESUMO

Mycobacterium indicus pranii (MIP) is a non-pathogenic strain of mycobacterium and has been used as a vaccine against tuberculosis and leprosy. Here, we investigated the role of different pattern recognition receptors in the recognition of heat-killed MIP by macrophages. Treatment of macrophages with MIP caused upregulation of pro-inflammatory cytokines (like TNFα and IL-1ß) which was mediated through both TLR2 and NOD2, as revealed by our knockdown and/or knockout studies. Mechanistically, MIP-induced macrophage activation was shown to result in NF-κB activation and drastically abrogated by MyD88 deficiency, suggesting its regulation via an MyD88-dependent, NF-κB pathway. Interestingly, the IFN-inducible cytokine, CXCL10, which is known target of the TRIF-dependent TLR pathway was found to be upregulated in response to MIP but, in an MyD88-dependent manner. Collectively, these results demonstrate macrophages to recognize and respond to MIP through a TLR2, NOD2 and an MyD88-dependent pathway. However, further studies should clarify whether additional TLR-dependent or -independent pathways also exist in regulating the full spectrum of MIP action on macrophage activation.


Assuntos
Ativação de Macrófagos , Macrófagos Peritoneais/microbiologia , Mycobacterium/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Proteína Adaptadora de Sinalização NOD2/imunologia , Receptor 2 Toll-Like/imunologia , Animais , Quimiocina CXCL10/imunologia , Feminino , Macrófagos Peritoneais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/imunologia
14.
Int J Cancer ; 130(4): 865-75, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21455983

RESUMO

Mycobacterium indicus pranii (MIP) is approved for use as an adjuvant (Immuvac/Cadi-05) in the treatment of leprosy. In addition, its efficacy is being investigated in clinical trials on patients with tuberculosis and different tumors. To evaluate and delineate the mechanisms by which autoclaved MIP enhances anti-tumor responses, the growth of solid tumors consisting of Sp2/0 (myeloma) and EL4 (thymoma) cells was studied in BALB/c and C57BL/6 mice, respectively. Treatment of mice with a single intra-dermal (i.d.) injection of MIP 3 days after Sp2/0 implantation greatly suppresses tumor growth. MIP treatment of tumor bearing mice lowers Interleukin (IL)6 but increases IL12p70 and IFNγ amounts in sera. Also, increase in CD8(+) T cell mediated lysis of specific tumor targets and production of high amounts of IL2 and IFNγ by CD4(+) T cells upon stimulation with specific tumor antigens in MIP treated mice is observed. Furthermore, MIP is also effective in reducing the growth of EL4 tumors; however, this efficacy is reduced in Ifnγ(-/-) mice. In fact, several MIP mediated anti-tumor responses are greatly abrogated in Ifnγ(-/-) mice: increase in serum Interleukin (IL)12p70 amounts, induction of IL2 and lysis of EL4 targets by splenocytes upon stimulation with specific tumor antigens. Interestingly, tumor-induced increase in serum IL12p70 and IFNγ and reduction in growth of Sp2/0 and EL4 tumors by MIP are not observed in nonobese diabetic severe combined immunodeficiency mice. Overall, our study clearly demonstrates the importance of a functional immune network, in particular endogenous CD4(+) and CD8(+) T cells and IFNγ, in mediating the anti-tumor responses by MIP.


Assuntos
Adjuvantes Imunológicos/farmacologia , Citotoxicidade Imunológica , Interferon gama/fisiologia , Mycobacterium/imunologia , Neoplasias Experimentais/terapia , Linfócitos T/imunologia , Adjuvantes Imunológicos/uso terapêutico , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Células Th1/imunologia
15.
Indian J Med Res ; 134(5): 696-703, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22199110

RESUMO

BACKGROUND & OBJECTIVES: Mycobacterium w (M.w) is a saprophytic cultivable mycobacterium and shares several antigens with M. tuberculosis. It has shown good immunomodulation in leprosy patients. Hence in the present study, the efficacy of M.w immunotherapy, alone or in combination with multi drug chemotherapeutic regimens was investigated against drug sensitive M. tuberculosis H37Rv and three clinical isolates with variable degree of drug resistance in mice. METHODS: BALB/c mice were infected with M. tuberculosis H37Rv (susceptible to all first and second line drugs) and three clinical isolates taken from the epository of the Institute. The dose of 200 bacilli was used for infection via respiratory route in an aerosol chamber. Chemotherapy (5 days/wk) was given one month after infection and the vaccinated group was given a dose of 1x107 bacilli by subcutaneous route. Bacterial load was measured at 4 and 6 wk after initiation of chemotherapy. RESULTS: M.w when given along with chemotherapy (4 and 6 wk) led to a greater reduction in the bacterial load in lungs and other organs of TB infected animals compared to. However, the reduction was significantly (P<0.05) more in terms of colony forming units (cfu) in both organs (lungs and spleen). CONCLUSION: M.w (as immunomodulator) has beneficial therapeutic effect as an adjunct to chemotherapy.


Assuntos
Vacinas Bacterianas/imunologia , Vacinas Bacterianas/uso terapêutico , Mycobacterium tuberculosis/patogenicidade , Mycobacterium/imunologia , Tuberculose/microbiologia , Animais , Antituberculosos/uso terapêutico , Carga Bacteriana , Vacinas Bacterianas/administração & dosagem , Modelos Animais de Doenças , Combinação de Medicamentos , Resistência a Medicamentos , Humanos , Imunoterapia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/imunologia , Tuberculose/tratamento farmacológico , Tuberculose/imunologia
16.
Clin Vaccine Immunol ; 18(7): 1097-103, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21613461

RESUMO

Leprosy is an infectious disease caused by Mycobacterium leprae, which is a noncultivable bacterium. One of the principal goals of leprosy research is to develop serological tests that will allow identification and early treatment of leprosy patients. M. habana is a cultivable nonpathogenic mycobacterium and candidate vaccine for leprosy, and several antigens that cross-react between M. leprae and M. habana have been discovered. The aim of the present study was to extend the identification of cross-reactive antigens by identifying M. habana proteins that reacted by immunoblotting with antibodies in serum samples from leprosy patients but not with antibodies in sera from tuberculosis (TB) patients or healthy donors (HDs). A 28-kDa antigen that specifically reacted with sera from leprosy patients was identified. To further characterize this antigen, protein spots were aligned in two-dimensional polyacrylamide gels and Western blots. Spots cut out from the gels were then analyzed by mass spectrometry. Two proteins were identified: enoyl-coenzyme A hydratase (lipid metabolism; ML2498) and antigen 85B (Ag85B; mycolyltransferase; ML2028). These proteins represent promising candidates for the design of a reliable tool for the serodiagnosis of lepromatous leprosy, which is the most frequent form in Mexico.


Assuntos
Anticorpos Antivirais/sangue , Antígenos de Bactérias/imunologia , Reações Cruzadas/imunologia , Enoil-CoA Hidratase/imunologia , Hanseníase/imunologia , Mycobacterium/imunologia , Reações Antígeno-Anticorpo , Proteínas de Bactérias/imunologia , Humanos , Hanseníase/diagnóstico , Mycobacterium leprae/imunologia
17.
PLoS One ; 6(2): e17093, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21347304

RESUMO

Mycobacterium indicus pranii (MIP), also known as Mw, is a saprophytic, non-pathogenic strain of Mycobacterium and is commercially available as a heat-killed vaccine for leprosy and recently tuberculosis (TB) as part of MDT. In this study we provide evidence that cell-free supernatant collected from original MIP suspension induces rapid and enhanced apoptosis in mouse peritoneal macrophages in vitro. It is demonstrated that the MIP cell-free supernatant induced apoptosis is mitochondria-mediated and caspase independent and involves mitochondrial translocation of Bax and subsequent release of AIF and cytochrome c from the mitochondria. Experiments with pharmacological inhibitors suggest a possible role of PKC in mitochondria-mediated apoptosis of macrophages.


Assuntos
Apoptose/efeitos dos fármacos , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Mycobacterium/citologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Fator de Indução de Apoptose/metabolismo , Vacinas Bacterianas/efeitos adversos , Caspase 3/metabolismo , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Meios de Cultivo Condicionados/metabolismo , Meios de Cultivo Condicionados/farmacologia , Citocromos c/metabolismo , Regulação para Baixo/efeitos dos fármacos , Feminino , Injeções , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mycobacterium/imunologia , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Proteína Quinase C-delta/antagonistas & inibidores , Proteína Quinase C-delta/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteólise/efeitos dos fármacos , Proteômica , Proteína X Associada a bcl-2/metabolismo
18.
Microbiology (Reading) ; 156(Pt 12): 3744-3753, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20688816

RESUMO

The structure of cord factor was studied in several strains of Mycobacterium simiae, including 'habana' TMC 5135, considered as highly immunogenic in experimental tuberculosis and leprosy. The mycolic acids liberated from cord factor were identified in all cases as α'-, α- and keto-mycolates. According to the general NMR and MS data, α'-mycolates were mono-unsaturated and contained from 64 to 68 carbon atoms, whereas α-mycolates mainly presented two 2,3-disubstituted cyclopropane rings and a chain length of 80-91 carbon atoms; keto-mycolates mostly contained one cyclopropane ring and 85-91 carbon atoms. Taking into account the (1)H-NMR results, strains varied in the ratio of the different mycolates, and the high levels of keto-mycolates found in the cord factors of TMC 5135 and ATCC 25275(T) stood out. Notably, MS revealed that the odd carbon number series of α-mycolates (C87-C89) predominated in the cord factor of TMC 5135, in contrast to the remaining studied strains, in which the even (C84-C86) and odd carbon number series appeared more equal. The fine structural differences detected among the cord factors studied did not seem to be relevant to the general capacity of these molecules to induce the secretion of tumour necrosis factor alpha, as the cord factors from several strains of M. simiae (TMC 5135, IPK-342 and ATCC 25275(T)) induced similar amounts of this cytokine in RAW 264.7 cells.


Assuntos
Fatores Corda/química , Fatores Corda/imunologia , Mycobacterium/imunologia , Tuberculose/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Linhagem Celular , Fatores Corda/genética , Humanos , Camundongos , Estrutura Molecular , Mycobacterium/química , Mycobacterium/genética , Tuberculose/microbiologia
19.
J Clin Immunol ; 30(1): 157-66, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19536643

RESUMO

INTRODUCTION: Genetic associations of American sarcoidosis susceptibility implicate MHC class II allele, DRB1*1101. We previously reported immune recognition of Mycobacterium peptides from peripheral cells of 26 sarcoidosis subjects, 24 PPD- healthy volunteers, and eight with latent tuberculosis infection. MATERIALS AND METHODS: In order to further link these genetic and immunologic pillars of sarcoidosis pathogenesis, we performed flow cytometry on these same subjects to identify the cells responsible for immune responses to ESAT-6 and katG peptides, followed by HLA typing to determine allelic associations with recognition. DISCUSSION AND CONCLUSION: Sarcoidosis CD4+ T cells were primarily responsible for the systemic responses. Recognition was inhibited by monoclonal antibody against HLA-DR and HLA-DQ, but not HLA-DP. Immune recognition of ESAT-6 peptide NNALQNLARTISEAG was associated with possession of DRB1*1101. ESAT-6 and katG presented by antigen-presenting cells expressing DRB1*1101-induced Th-1 responses from sarcoidosis T cells, thus providing a mechanistic insight for the association of HLA DRB1*1101 with sarcoidosis, and sarcoidosis T cell interaction with microbial antigens.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Catalase/metabolismo , Antígenos HLA-DR/metabolismo , Tuberculose Latente/genética , Tuberculose Latente/imunologia , Mycobacterium/imunologia , Alelos , Sequência de Aminoácidos , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Catalase/imunologia , Separação Celular , Células Cultivadas , Citometria de Fluxo , Estudos de Associação Genética , Predisposição Genética para Doença , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Cadeias HLA-DRB1 , Teste de Histocompatibilidade , Interações Hospedeiro-Patógeno/genética , Humanos , Interferon gama/metabolismo , Tuberculose Latente/microbiologia , Tuberculose Latente/fisiopatologia , Ativação Linfocitária , Dados de Sequência Molecular , Mycobacterium/patogenicidade , Sarcoidose Pulmonar , Estados Unidos
20.
J Mol Biol ; 392(2): 381-92, 2009 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-19577573

RESUMO

Mycobacteria are major human pathogens responsible for such serious and widespread diseases as tuberculosis and leprosy. Among the evolutionary adaptations essential for pathogenicity in mycobacteria is a complex carbohydrate-rich cell-wall structure that contains as a major immunomodulatory molecule the polysaccharide lipoarabinomannan (LAM). We report here crystal structures of three fragments from the non-reducing termini of LAM in complex with a murine antibody Fab fragment (CS-35Fab). These structures reveal for the first time the three-dimensional structures of key components of LAM and the molecular basis of LAM recognition at between 1.8- and 2.0-A resolution. The antigen-binding site of CS-35Fab forms three binding pockets that show a high degree of complementarity to the reducing end, the branch point and one of the non-reducing ends of the Y-shaped hexasaccharide moiety found at most of the non-reducing termini of LAM. Structures of CS-35Fab bound to two additional tetrasaccharides confirm the general mode of binding seen in the hexasaccharide and indicate how different parts of LAM are recognized. Altogether, these structures provide a rational basis for understanding the overall architecture of LAM and identify the key elements of an epitope that may be exploited for the development of novel and more effective anti-mycobacterial vaccines. Moreover, this study represents the first high-resolution X-ray crystallographic investigation of oligofuranoside-protein recognition.


Assuntos
Anticorpos Antibacterianos/química , Lipopolissacarídeos/química , Mycobacterium/química , Polissacarídeos Bacterianos/química , Sequência de Aminoácidos , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Sequência de Carboidratos , Cristalografia por Raios X , Lipopolissacarídeos/imunologia , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Mycobacterium/imunologia , Polissacarídeos Bacterianos/imunologia , Ligação Proteica , Estrutura Terciária de Proteína
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