PMA/CD3 and PMA/CD28 effects on purified primary human CD4+ T cells. Purified CD4+ T cells were stimulated with anti-CD3/CD28, PMA/CD3 and PMA/CD28 and cultured for 24 hours in the presence or absence of pathway inhibitors for Lck (A420983; 1 μM) and PKC(AEB071; 1 μM). Culture supernatants were analyzed for IFNγ, production (A), mRNA expression of the Th1 master transcription factor T-bet (B), the production of the Th2 cytokine IL-13 (C) and expression of the Th2 master transcription factor GATA3 (D). Message RNA expression was normalized against ribosomal house hold gene RPL19. Data are presented of three independent experiments using purified human CD4+ T cells from three different healthy donors. Data are presented as mean + SD. Significance of differences are indicated by ** p < 0.01, * p < 0.05, using a mann-withney U-test.