title: Effect of Mycobacterium tuberculosis-specific 10-kilodalton antigen on macrophage release of tumor necrosis factor alpha and nitric oxide.
abstract: Secreted proteins of Mycobacterium tuberculosis are major targets of the specific immunity in tuberculosis and constitute promising candidates for the development of more efficient vaccines and diagnostic tests. We show here that M. tuberculosis-specific antigen 10 (MTSA-10, originally designated CFP-10) can bind to the surface of mouse J774 macrophage-like cells and stimulate the secretion of the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha). MTSA-10 also synergized with gamma interferon (IFN-gamma) for the induction of the microbicidal free radical nitric oxide (NO) in J774 cells, as well as in bone marrow-derived and peritoneal macrophages. On the other hand, pretreatment of J774 cells with MTSA-10 markedly reduced NO but not TNF-alpha or interleukin 10 (IL-10) release upon subsequent stimulation with lipopolysaccharide or the cell lysate of M. tuberculosis. The presence of IFN-gamma during stimulation with M. tuberculosis lysate antagonized the desensitizing effect of MTSA-10 pretreatment on macrophage NO production. The activation of protein tyrosine kinases (PTK) and the serine/threonine kinases p38 MAPK and ERK was apparently required for MTSA-10 induction of TNF-alpha and NO release, as revealed by specific kinase inhibitors. However, only p38 MAPK activity, not PTK or ERK activity, was partly responsible for MTSA-10-mediated macrophage desensitization. The modulation of macrophage function by MTSA-10 suggests a novel mechanism for its involvement in immunopathogenesis of tuberculosis and might have implications for the prevention, diagnosis, and therapy of this disease.
authors.affiliation: Immunology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Trajkovic
authors.forename: Gyanesh
authors.initials: G
authors.lastname: Singh
authors.forename: Balwan
authors.initials: B
authors.lastname: Singh
authors.forename: Sarman
authors.initials: S
authors.lastname: Singh
authors.forename: Pawan
authors.initials: P
authors.lastname: Sharma
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D009569:Nitric Oxide / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; D014409:Tumor Necrosis Factor-alpha; C072681:Mycobacterium tuberculosis antigens; D009569:Nitric Oxide