[Function and molecular structure of IL-12]

Abstract

Natural killer cell stimulatory factor (NKSF), also called cytotoxic lymphocyte maturation factor (CLMF) or interleukin-12, is a novel cytokine of a 70 kDa heterodimer, composed of two covalently linked glycosylated chains of 40 and 35 kDa. NKSF was originally identified in the supernatant fluid of human EB virus-transformed B lymphoblastoid cell lines. NKSF has been shown to: (a) induce interferon-gamma production from both T and NK cells and synergize in this effect with interleukin-2 (IL-2), mitogens, phorbol diesters, anti-CD3 antibodies, and allogeneic antigens; (b) exert a comitogenic effect on fresh resting T cells together with lectins or phorbol diesters; (c) mediate a direct mitogenic effect on activated T or NK cell blasts; (d) enhance the cytotoxic activity of resting peripheral blood NK cells; and (e) synergize with IL-2 in the generation of lymphokine-activated killer cells.