FIG. 9.

Involvement of MAP kinases ERK1/2 in the Tat-induced production of IL-10. (A) Western blot analysis of the activation of MAP kinases ERK1/2 by Tat. Cytoplasmic protein extracts were prepared from monocytes (2 × 10⁶) treated with PMA at 50 ng/ml (lanes 2 and 6) or 10 nM (lanes 3 and 7) or 100 nM (lanes 4 and 8) Tat for 15 or 30 min. Visualization was done with an antibody recognizing total ERK1/2 or only phosphorylated ERK1/2 (pERK1/2). These results are representative of two independent experiments done on cells from two different donors. Ctr, control. (B) Effect of PD 98 059 (PD) at 10 or 100 μM, an inhibitor of MAP kinases ERK1/2, on monocytes (10⁶) treated with 10 nM Tat (T). Similar results were obtained with cells from three different donors.