title: Separation of helper T cells from suppressor T cells expressing different Ly components. II. Activation by antigen: after immunization, antigen-specific suppressor and helper activities are mediated by distinct T-cell subclasses.
abstract: Cells of the Lyl subclass generate helper activity in both primary and secondary responses to sheep erythrocytes (SRBC). In contrast, after priming with SRBC, cells of the Ly-2+ subclasses, in particular Ly23 cells, have suppressive activity. The degree of Ly23-mediated suppression is directly proportional to the amount of antigen (SRBC) used for priming. Suppression by Ly23 cells is specific, because Ly23 cells from SRBC-primed animals do not suppress the response to horse erythrocytes, and vice versa. Thus, both cytotoxic and specific suppressor functions are mediated by T cells of a subclass, provisionally designated TCS, which can be distinguished from helper T cells (TH), by their Ly phenotypes. It remains to be determined whether killing and suppression are functionally interrelated properties of a single Ly23 subclass, or whether the Ly23 population comprises two subclasses whose surface phenotypes are not yet distinguishable by immunogenetic criteria.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000941:Antigens; D002469:Cell Separation; D004912:Erythrocytes / Q000276:immunology; D007111:Immunity, Cellular; D007156:Immunologic Memory; D007165:Immunosuppression Therapy; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D010641:Phenotype; D013154:Spleen / Q000276:immunology; D013499:Surface Properties; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens