Specific binding of antigen onto human T lymphocytes.
Human T lymphocytes sensitized to Candida albicans (CA) were shown to proliferate in cultures induced with mannan, a ramified polysaccharide extracted from the cell well of CA. We presently describe that, when we used strongly labeled [3H]mannan, antigen-specific T blast cells were able to bind the labeled mannan on their membrane. The observations that irrelevant blast cells did not bind [3H]mannan, and that mannan-specific blast cells did not bind tritiated pneumococcal polysaccharide SIII, indicate the specificity of mannan binding. Mannan binding was reversible and saturable. Mannan binding on T blast cells was inhibited by preincubation with monoclonal antibodies to T3 but not to other T cell-related molecules. The characteristics of this receptor suggest its identity with the T cell receptor for antigen. The direct binding of mannan could be either due to a cross-linking of the receptor by multivalent mannan or to a recognition of mannan in association with HLA-DQ molecules, as suggested by partial blocking of mannan binding using anti-HLA-DQ monoclonal antibodies.
D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology; D002176:Candida albicans / Q000276:immunology; D006023:Glycoproteins / Q000276:immunology; D006683:HLA-DQ Antigens; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn; D008213:Lymphocyte Activation; D008351:Mannans / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology*; D014316:Tritium
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006023:Glycoproteins; D006683:HLA-DQ Antigens; D000949:Histocompatibility Antigens Class II; D008351:Mannans; D014316:Tritium