Interleukin-2 versus phorbol-ester-induced cellular events in normal T-lymphocytes.
Activation of primary T-lymphocytes (T-cells) is dependent on interactions with the T3/T-cell antigen receptor complex which results in expression of cell surface receptors for the lymphocytotrophic growth factor interleukin-2 (IL-2). In the present communication we have compared the cellular responses to phorbol ester with IL-2-induced cellular responses. Thus, the effect of respective ligand on T-cell growth, the level of expression and composition of two distinct affinity classes of IL-2 receptors, and phosphorylation of an 80,000 mol. wt cellular substrate for the Ca2+-dependent, phospholipid-dependent protein kinase C (PK-C) was analysed. The results demonstrate that only the high affinity IL-2 receptor class is induced by phorbol esters and that both IL-2 and cell surface expression of its high affinity receptor is required for induction of low affinity IL-2 receptors. Moreover, IL-2 receptor signalling seems not to involve activation of PK-C and the results suggest that another intracellular pathway, distinct from the PK-C pathway which induces high affinity IL-2 receptors, is employed in the transmission of IL-2 growth promoting signals.
D002478:Cells, Cultured; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D007700:Kinetics; D008970:Molecular Weight; D010703:Phorbol Esters / Q000494:pharmacology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000187:drug effects* / Q000254:growth & development
D007376:Interleukin-2; D010703:Phorbol Esters; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011493:Protein Kinase C