title: Inhibition of the mixed lymphocyte proliferative response by phorbol esters.
abstract: The phorbol diester, 12-O-tetradecanoyl-phorbol-13-acetate, a potent cocarcinogen in mice, blocks the induction of DNA synthesis in lymphocytes undergoing the mixed lymphocyte response. At 10(-7) M diester, the induced DNA synthesis is inhibited almost completely (99%). This action of the diester affects some early step in the response which is necessary for the triggering of cell replication; on-going DNA replication is not significantly affected. Phorbol 12,13-diacetate, a less potent analogue in tumor promotion in vivo, is also a less potent inhibitor of the mixed lymphocyte response (75% inhibition at 10(-6) M). Phorbol, the parent alcohol, is not effective in either system. The use of phorbol diesters in the molecular dissection of mixed lymphocyte responses is discussed.
mesh_terms: D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013997:Time Factors
chemical_list: D006064:Gonadotropins, Equine; D004247:DNA