title: On the role of I-A antigens in lectin- and antigen-induced interleukin 2 production.
abstract: The role of I-A molecules in lectin- and antigen-induced interleukin 2 (IL2) production has been analyzed using monoclonal antibodies. Both lectin- and antigen [plus major histocompatibility complex (MHC)]-induced IL2 production were profoundly inhibited by monoclonal anti-I-A antibodies, whereas monoclonal anti-D and anti-K antibodies had no effect. The anti-I-A-mediated inhibition of lectin-induced IL2 production was fully overcome by addition of interleukin 1 (IL 1), while no reconstitution was observed in antigen (plus MHC)-specific induction. Anti-I-A antibodies were also found to inhibit the T cell-independent induction of IL 1 production. I-A antigens appear, therefore, to play two distinct roles in the induction of IL 2 production: (a) I-A molecules are directly involved in mediating activation signals to the macrophages at the level of IL 1 production; (b) I-A epitopes act as restricting elements in specific antigen recognition by T helper cells at the level of IL 2 production, a requirement which is overcome by lectin.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007376:Interleukin-2 / Q000096:biosynthesis*; D037102:Lectins / Q000494:pharmacology*; D008285:Major Histocompatibility Complex; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D037102:Lectins; D003208:Concanavalin A