Interleukin 2 and a lactogen regulate proliferation and protein phosphorylation in Nb2 cells.
Cell proliferation and protein phosphorylation in response to activation of lactogenic and interleukin 2 (IL-2) receptors were studied in Nb2 cells, a rat T-lymphocyte cell line. Human growth hormone (hGH) and rat IL-2 stimulated Nb2-cell proliferation to approximately the same degree, and the actions of both mitogens were potentiated by phorbol 12-myristate 13-acetate (PMA). A monoclonal antibody specific for the rat IL-2 receptor inhibited the mitogenic actions of rat IL-2, but not those of hGH. Exposure of Nb2 cells to either mitogen for 2-3 h increased phosphorylation of an 18,600-Da protein and decreased phosphorylation of a 15,600-Da protein. PMA also inhibited phosphorylation of the latter protein, but, by itself, PMA did not stimulate phosphorylation of the 18,600-Da protein. Overall, the results suggest that hGH and IL-2 act through separate receptors to stimulate proliferation of Nb2 cells, and that some of the actions of both mitogens may be mediated, in part, through regulation of protein phosphorylation.
D000911:Antibodies, Monoclonal; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D007376:Interleukin-2 / Q000494:pharmacology*; D010766:Phosphorylation; D010928:Placental Lactogen / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000502:physiology; D015375:Receptors, Interleukin-2; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D011506:Proteins; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D010928:Placental Lactogen; D013755:Tetradecanoylphorbol Acetate