Induction of synthesis of the cytolytic C9 (ninth component of complement)-related protein in human peripheral mononuclear cells by monoclonal antibody OKT3 or interleukin 2: correlation with cytotoxicity and lymphocyte phenotype.
Synthesis of the cytolytic C9-related protein (C9RP) was induced by activation of resting human peripheral T lymphocytes with the anti-CD3 antibody OKT3 or interleukin 2. Comparison of cellular cytotoxicity and C9RP content at various times during activation yielded a coefficient of correlation r = 0.92. During OKT3 stimulation of peripheral mononuclear cells, maximal C9RP content and cytotoxicity were observed by day 2 or 3, with subsequent decline to baseline values by day 5, whereas during interleukin 2 stimulation, both parameters reached the maximal level at days 3-5. After fluorescence-activated cell sorting, C9RP and cytotoxicity were quantitated in CD4+, CD8+, and Leu-19+ subsets. In OKT3-activated CD8+ cells, C9RP increased to approximately 3 X 10(6) molecules per cell, with a corresponding increase in lysis of human melanoma cells mediated by anti-CD3-anti-melanoma monoclonal antibody conjugates. Interleukin 2-stimulated CD8+ cells showed similar increases, but cytotoxicity was conjugate-independent. Activated CD4+ cells showed minimal increase in C9RP content. Leu-19+ cells, which exhibit natural killer cell activity, had a high C9RP content (approximately 2.5 X 10(6) molecules per cell) before stimulation.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D003186:Complement C9 / Q000096:biosynthesis*; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology*; D008213:Lymphocyte Activation; D009000:Monocytes / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D003186:Complement C9; D007376:Interleukin-2