Suppressor-target interaction in alloantigen induced responses: induction of a second cell in the suppressive pathway.
The sequence of events involved in MLR-TsF-induced suppression of the mixed lymphocyte response has been investigated. It is demonstrated in this report that MLR-TsF, which is secreted by predominantly Ly-2+ alloantigen-primed splenic T cells, carries out its suppressive function through the active recruitment of an intermediary suppressor cell. Substantial suppression of the proliferative response is observed when unprimed BALB/c splenocytes are cultured with MLR-TsF and then added as irradiated regulator cells to MLR. This inductive process is dependent on factor concentration, requires a 48-hr exposure of cells to MLR-TsF, and occurs in the absence of added priming strain alloantigen. The target cell involved in this factor-cell interaction is characterized as a nonadherent, Ly-1+2+ T cell resistant to complement-dependent cytotoxicity with a monoclonal anti-Thy-1.2 antibody. In addition, second-order suppression does not appear to operate in an antigen-specific manner. These studies indicate that MLR suppression is a complex process involving a series of interactions between cellular components and their soluble regulatory products.
D000818:Animals; D000950:Antigens, Ly / Q000276:immunology*; D002448:Cell Adhesion; D000939:Epitopes; D007700:Kinetics; D008211:Lymphocyte Cooperation; D007959:Lymphocyte Culture Test, Mixed; D008222:Lymphokines / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010641:Phenotype; D013491:Suppressor Factors, Immunologic; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013997:Time Factors
D000950:Antigens, Ly; D000939:Epitopes; D008222:Lymphokines; D013491:Suppressor Factors, Immunologic