title: Poly A:U-induced secretion of T-lymphocyte helper factors.
abstract: In vitro exposure of mouse thymocytes to complexes of polyadenylic:polyuridylic acid (poly A:U) effected, within 6 h, the release of soluble factor(s) capable of nonspecifically enhancing IgM and IgG plaque-forming cells (PFCs) in in vitro primary and secondary spleen cell responses to burro erythrocytes. Poly A:U stimulation was, most likely, polyclonal, since production of soluble factor(s) occurred in the absence of antigen and in serum-free culture media. Poly A:U-induced soluble factor(s) were not capable of substituting for T cells but were dependent on T cells for the expression of PFC enhancement. These data support the hypothesis that the mechanism of poly A:U's adjuvant action is polyclonal stimulation of T cells, causing early induction and release of nonspecific, soluble PFC-enhancing factor(s).
mesh_terms: D000818:Animals; D000941:Antigens; D002478:Cells, Cultured; D003165:Complement System Proteins; D007106:Immune Sera; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects*; D008211:Lymphocyte Cooperation / Q000187:drug effects; D051379:Mice; D011063:Poly A-U / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D007106:Immune Sera; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011063:Poly A-U; D003165:Complement System Proteins