title: OKT8 antibody inhibits OKT3-induced IL 2 production and proliferation in OKT8+ cells.
abstract: We studied IL 2 production and proliferation induced by OKT3 mitogenic monoclonal antibody in the OKT8+ T cell subset. OKT3 antibody induced IL 2 production and proliferation in OKT8+ cells in a typical time-dependent manner: maximal IL 2 levels were found in 24 hr culture supernatants; maximal proliferation was found on day 3. OKT3 antibody was mitogenic over a wide range of concentrations (0.125 to 500 ng/ml). The presence of OKT8 antibody (greater than or equal to 100 ng/ml) in these cultures resulted in almost complete inhibition of IL 2 production and proliferation. Kinetic studies demonstrate that OKT8 antibody suppresses both IL 2 production and response to exogenous IL 2 in OKT8+ cells when added within the first 2 hr of culture. After 14 to 20 hr of culture, addition of OKT8 only blocks IL 2 production but not the IL 2 response of activated OKT8+ cells. The specificity of inhibition by OKT8 antibody of OKT3 mitogenicity on OKT8+ cells was confirmed by the failure of Leu-I and OKT4 antibody to produce the same effect and by the lack of inhibition by OKT8 antibody of OKT3-induced IL 2 production and proliferation in OKT4+ cells.
mesh_terms: D000911:Antibodies, Monoclonal / Q000502:physiology*; D000918:Antibody Specificity; D001667:Binding, Competitive; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D007700:Kinetics; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D008934:Mitogens; D011948:Receptors, Antigen, T-Cell