Regulation of p42/p44, p38, and NF-κB phosphorylation in T cells. PHA-stimulated PBLs were cultured 14 days. After culture, the T cells were treated 15 minutes with vehicle, PGE₂ (1 μM), or ISO (10 μM), then stimulated 10 minutes with 5 nM PMA. The cells were then analyzed for phosphorylation of ERK, p38, and NF-κB by flow cytometry. (A) Representative histograms are shown for the effects of PGE₂ on PMA-induced phosphorylation. (B) The percent inhibition (mean ± SD, n = 4-6) of PMA-induced phosphorylation is presented for each condition (bottom). ^*P < .05 versus zero-inhibition; †P < .05 for effects of PGE₂ versus ISO.