title: Mycobacterium tuberculosis ManLAM inhibits T-cell-receptor signaling by interference with ZAP-70, Lck and LAT phosphorylation.
abstract: Immune evasion is required for Mycobacterium tuberculosis to survive in the face of robust CD4(+) T cell responses. We have shown previously that M. tuberculosis cell wall glycolipids, including mannose capped lipoarabinomannan (ManLAM), directly inhibit polyclonal murine CD4(+) T cell activation by blocking ZAP-70 phosphorylation. We extended these studies to antigen-specific murine CD4(+) T cells and primary human T cells and found that ManLAM inhibited them as well. Lck and LAT phosphorylation also were inhibited by ManLAM without affecting their localization to lipid rafts. Inhibition of proximal TCR signaling was temperature sensitive, suggesting that ManLAM insertion into T cell membranes was required. Thus, M. tuberculosis ManLAM inhibits antigen-specific CD4(+) T cell activation by interfering with very early events in TCR signaling through ManLAM's insertion in T cell membranes.
authors.affiliation: Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106, United States. rnmb23@gmail.com
authors.forename: Robert N
authors.initials: RN
authors.lastname: Mahon
authors.forename: Obondo J
authors.initials: OJ
authors.lastname: Sande
authors.forename: Roxana E
authors.initials: RE
authors.lastname: Rojas
authors.forename: Alan D
authors.initials: AD
authors.lastname: Levine
authors.forename: Clifford V
authors.initials: CV
authors.lastname: Harding
authors.forename: W Henry
authors.initials: WH
authors.lastname: Boom
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000276:immunology / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000276:immunology / Q000378:metabolism; D021962:Membrane Microdomains / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010750:Phosphoproteins / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000276:immunology / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C110810:LAT protein, human; C491734:Lat protein, mouse; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; C050016:lipoarabinomannan; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; C497262:Zap70 protein, mouse