Physiological regulation of antigen binding to T cells: role of a soluble macrophage factor and of interferon.
A soluble product of macrophages (MF) and mouse viral interferon (IF) increase both major histocompatibility antigenic determinants and the number of antigen-binding cells in nonstimulated T cell-enriched mouse lymphocyte cultures. MF increases Ia and not H-2 antigens; IF increases H-2 but not Ia antigens. The increased antigen binding due to MF can be inhibited by anti-Ia but not by anti-H-2 sera, whereas IF-induced binding is sensitive to anti-H-2 but not to anti-Ia sera. The specificity of IF- or MF-induced binding of branched synthetic polypeptides by T cells is different from that of B cells and similar to the specificity of the Ir gene regulation. MF increases antigen binding only in Ir high-responder animals. The IF-induced antigen binding is not dependent on the Ir genotype. MF-reactive cells express the Ly-1 marker, and the IF-reactive antigen binders express the Ly-2 phenotype. It is suggested that MF and IF are physiological mediators of antigen binding by T cells.
D000818:Animals; D000937:Antigen-Antibody Reactions; D000941:Antigens; D002462:Cell Membrane / Q000276:immunology; D005802:Genes, MHC Class II; D006183:H-2 Antigens / Q000235:genetics; D007372:Interferons / Q000502:physiology*; D007518:Isoantibodies; D007519:Isoantigens / Q000235:genetics; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D011485:Protein Binding; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D006183:H-2 Antigens; D007518:Isoantibodies; D007519:Isoantigens; D007372:Interferons