FIG 1.

HIV gp120, but not CCL4, upmodulates IL-6 expression via CCR5. MDDCs at day 6 of culture were treated with different concentrations of gp120 and LPS (10 ng/ml) (A) or for different time periods with 5 μg/ml gp120 (CN54 and ADA strain) and BaL-AT2 (46.783 ng/ml p24) (B and C). To test the specificity of gp120-induced effects, MDDCs were preincubated for 1 h with or without sCD4 (2 μg/ml), anti-CD4 (2 μg/ml), or Tak779 (5 μM) and then exposed to gp120 (5 μg/ml) for 18 h or treated with CCL4 (100 nM) for the indicated times (D). For panels A, B, and D, supernatants were collected and IL-6 content was measured by ELISA. Data are expressed as means ± standard errors (SE) from six (A) or four (B and D) independent experiments. P values were calculated by Student's t test, and statistical significance is indicated. *, P < 0.05; **, P < 0.005 (gp120 versus the untreated control and Tak779 plus gp120 versus gp120 alone). (C) Total RNA was extracted and reverse transcribed, and real-time PCR was performed using primers specific for the human IL-6 gene and normalized with β actin. Data are expressed as means ± SE from five independent experiments performed. Results, analyzed by the relative quantification method (2^−ΔΔCT method), are shown as fold increase (FC) of IL-6 gene expression versus that of the untreated control. P values were calculated by Student's t test, and statistical significance is indicated (P < 0.05 [*] and P < 0.005 [**] for gp120 versus the untreated control).