R5 gp120-activated ERK 1/2 mediates nuclear localization of PI-PLC β1 and CCL2 secretion in MDM.

<p>(A) MDM were treated with R5 gp120 (3 µg/ml) for the indicated time periods or left untreated (control). Cells were then lysed and ERK 1/2 phosphorylation was detected by western blotting. The results from one representative experiment of 4 independently performed are shown. (B) MDM were treated as described in A and ERK 1/2 phosphorylation was analyzed by flow cytometry after 10 minutes of gp120 exposure. Blue and red lines represent control and gp120-treated cells, respectively. Black line represents background staining of isotype-matched control Ab. The results from one representative experiment of 4 independently performed are shown. (C) MDM were treated with PD98059 (10 µM) for 1 hour prior to R5 gp120 (3 µg/ml) or CCL4 (200 ng/ml) exposure for 20 minutes. Cells were then fixed, permeabilized, stained with anti-PI-PLC β1 Ab (pseudocolor gray) and examined by CLSM. Representative examples of 5 independent experiments are shown. The bars correspond to 20 µm. (D) MDM were treated with PD98059, U0126, U0124 (10 µM) or left untreated (control). After 1 hour, some cultures were exposed to R5 gp120 (3 µg/ml). After 24 hours of culture, supernatants were harvested and frozen before CCL2 determination. Data represent mean values (±SE) of the results obtained with MDM from 10 different donors. *p<0.05; ***p<0.001.