title: Association of protein kinase C activation with IL 2 receptor expression.
abstract: Tac antigen (as a measure of the IL 2 receptor) acquisition and regulation by IL 2, an antigen-receptor agonist (anti-T3), phorbol esters, and phytohemagglutinin (PHA) were studied. Phorbol esters stimulated de novo acquisition of Tac antigen, which was associated with the subcellular redistribution of protein kinase C (PK-C) from cytosol to particulate membranes of human T lymphocytes. PHA and anti-T3 (alpha-T3) antibody also stimulated a transient redistribution and activation of PK-C that reached a maximum within 20 min after stimulation. Both phorbol esters and alpha-T3 could increase Tac expression and stimulate PK-C translocation on 5 and 12 day activated T cells that were at the G0/G1 stage of the cell cycle due to IL 2 deprivation. Tac antigen-specific mRNA was seen in the nucleus within 2 hr after stimulation. In contrast, IL 2 alone could only increase Tac expression and stimulate PK-C translocation on day 5 but not day 12 activated T cells. IL 2 synergizes with alpha-T3 and phorbol ester for the regulation of Tac expression. Although IL 2 increased expression of Tac, the majority if not all of these receptors possessed low affinity for IL 2. These data suggest that the activation of PK-C is a common transmembrane signal shared by IL 2 and antigen stimulation. The results also imply that PK-C activation is necessary for the regulation of Tac antigen expression.
mesh_terms: D000328:Adult; D000954:Antigens, Surface / Q000096:biosynthesis / Q000276:immunology; D004789:Enzyme Activation; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism* / Q000502:physiology; D007399:Interphase; D008213:Lymphocyte Activation; D011493:Protein Kinase C / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000954:Antigens, Surface; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D011493:Protein Kinase C