title: Augmentation of mixed lymphocyte response. Stimulatory activity by phorbol ester.
abstract: The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) induces a variety of phenotypic changes on normal and malignant cells. In chronic and acute lymphocytic leukemia we have observed a marked augmentation in mixed lymphocyte reaction stimulatory capacity (MLRs) following pretreatment of leukemia blasts with TPA. We have now characterized the effects of TPA on MLRs utilizing the non-T, non-B lymphoblastic leukemia-cell line, HOON. Following pretreatment with TPA (optimal concentration, 1.6 X 10(-10) M), but not with other phorbol esters, there was a marked increase in MLRs, particularly at lower stimulator-cell concentrations. This effect was maximal following a 44-hr preincubation period and the enhancement in MLRs was not accompanied by changes in levels of Ia expression. This cell line provides a model for determining the molecular basis for the TPA-induced augmentation of stimulatory capacity in the mixed lymphocyte reaction.
mesh_terms: D015720:5'-Nucleotidase; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007945:Leukemia, Lymphoid / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects*; D007959:Lymphocyte Culture Test, Mixed; D009708:Nucleotidases / Q000378:metabolism; D010641:Phenotype; D010704:Phorbols / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D010704:Phorbols; D009708:Nucleotidases; D015720:5'-Nucleotidase; D013755:Tetradecanoylphorbol Acetate