title: Production of a suppressor factor by CD8+ lymphocytes activated by mycobacterial components.
abstract: The lipid component present in high-molecular-mass fractions with molecular masses of greater than 200 kDa derived from Mycobacterium tuberculosis extracts passaged through Sephacryl S.200 columns activate CD8+ lymphocytes to suppress lymphocyte blastogenesis. Suppression is mediated by the release of suppressor molecules by these CD8+ lymphocytes. Release of suppressor molecules occurs as early as 2 h following pulsing with the high-molecular-mass mycobacterial components and is maximal at 24 h, after which their release declines rapidly. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblotting indicates that the active components are carbohydrate moieties with approximate molecular masses of 122 to 148 kDa. Our results suggest a mechanism of interaction between mycobacteria and host mononuclear cells such that mycobacterial lipids, once exposed, activate CD8+ suppressor lymphocytes. Activation of these lymphocytes results in the release of carbohydrate-containing molecules that ultimately inhibit the blastogenesis of other lymphocytes.
authors.affiliation: Department of Immunology, School of Pathology, University of the Witwatersrand, Johannesburg, Republic of South Africa.
authors.forename: G
authors.initials: G
authors.lastname: Sussman
authors.forename: A A
authors.initials: AA
authors.lastname: Wadee
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D002478:Cells, Cultured; D003470:Culture Media; D006801:Humans; D008213:Lymphocyte Activation; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D013491:Suppressor Factors, Immunologic / Q000096:biosynthesis* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D003470:Culture Media; D013491:Suppressor Factors, Immunologic