title: Antigen-binding T cells as helper cells. Separation of helper cells by immune rosette formation.
abstract: The spleen T cells from mice immunized 6 days earlier with either chicken gamma globulin (CGG) or with donkey erythrocytes (DRC) were rosetted with CGG-coated sheep erythrocytes or with DRC. The immune rosettes (RFC) (antigen-binding cells) were separated from the bulk of nonrosette-forming cells (non-RFC) by 1-g velocity sedimentation and the RFC and non-RFC tested for helper activity in cooperative antihapten responses in vitro. RFC or non-RFC were mixed with normal or hapten-primed spleen cells, challenged with the appropriate hapten-carrier conjugate and cultured for 4 days in Marbrook tissue cultures. The helping activity was quantitated from the numbers of antihapten antibody-producing cells generated per culture. The results show that specific helper cell activity could be selectively recovered in the immune rosette-forming cell population whereas the non-RFC population was depleted of help. These findings indicate that the helper T cells express specific antigen binding receptors.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells; D000941:Antigens; D001666:Binding Sites, Antibody; D000939:Epitopes; D007104:Immune Adherence Reaction; D007114:Immunization; D051379:Mice; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D000939:Epitopes