Interleukin 1 and protein kinase C activator are dissimilar in their effects on Il-2 receptor expression and Il-2 secretion by T lymphocytes.
T lymphocytes respond to mitogenic stimulation by expressing the receptor for interleukin 2 (Il-2) and secreting Il-2; once the receptor is expressed, Il-2 induces these cells to proliferation. In the present report using mouse T lymphocytes, thymocytes, and the lymphoma cell line EL4, we studied receptor expression and Il-2 secretion as early parameters for T-lymphocyte activation in response to ionomycin, concanavalin A (Con A), 12-O-tetradecanoyl-phorbol 13-acetate (TPA), and interleukin 1 (Il-1). Il-1 is required for mitogenic response of lymphocyte preparations that are rigorously depleted of macrophages. On its own, Il-1 had very little effect on Il-2 secretion and Il-2 receptor expression by T lymphocytes. TPA strongly synergized with ionomycin both for Il-2 secretion and for Il-2 receptor expression whereas Il-1 did not. Il-1 required the simultaneous presence of ionomycin and TPA to have any demonstrable effect on T lymphocytes from spleen and on thymocytes. However, on EL4 cells which were also partially responsive to TPA alone, Il-1 showed strong synergy with TPA to induce Il-2 secretion and Il-2 receptor expression. The effect of Il-1 on EL4 cells was dose dependent where increasingly higher concentrations of Il-1 in the presence of a fixed concentration of TPA caused higher percentage of EL4 cells to become Il-2 receptor positive. The present results suggest that Il-1 does not cause its effect on T lymphocytes via the same mechanism of protein kinase C activation that has been proposed for TPA.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D004789:Enzyme Activation; D004987:Ethers / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1; D007376:Interleukin-2 / Q000032:analysis*; D015759:Ionomycin; D051379:Mice; D011493:Protein Kinase C / Q000032:analysis*; D011971:Receptors, Immunologic / Q000187:drug effects*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004987:Ethers; D007375:Interleukin-1; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A; D015759:Ionomycin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium