EVIDENCE FOR THE INVOLVEMENT OF LCK AND MAP KINASE (ERK-1) IN THE SIGNAL-TRANSDUCTION MECHANISM OF INTERLEUKIN-15

Human IL-15 is a cytokine expressed by a variety of tissues and cells including myeloid progenitor cells and monocytes. It shares biologic p roperties of IL-2 and utilizes the beta subunit of the IL-BR, IL-15 re gulates proliferation of activated B and Mt cells and stimulates chemo attraction in blood T-lymphocytes, effects which are inhibited by an a nti-IL-SR beta antibody. Because little is known about the mechanism(s ) by which IL-15 signal is transduced, this study was conducted to ide ntify some of the key molecules involved in IL-15-induced signaling ca scade(s). We report that IL-15 induces tyr phosphorylation of the p75I L-2R beta and p64IL-2R gamma subunits and She. Also, it activates both p561ck and MAPK (ERK-1). These results strongly suggest that LCK and MAPK may play vital roles in mediation of cellular activation by IL-15 . (C) 1997 Academic Press.