Effect of rTat on human monocyte chemotaxis and polarization. (A) Human monocytes (1.5 × 106/mL in PBMCs) were tested for their ability to migrate across a 5-μm pore-size polycarbonate filter in response to different rTat concentrations (•). Results of one experiment (performed in triplicate and representative of at least 3 independent experiments) are shown. In the same experiment, migration to an optimal concentration (10 nmol/L) of FMLP was 149 ± 9 monocytes. **P < .001; *P < .01 versus control (no rTat) by paired Dunnett's test. The effect of Ptox on rTat-induced migration was evaluated by preincubating cells with 1 μg/mL PTox for 90 minutes (○). **P < .001 versus respective Ptox-untreated cells. Results of one experiment (performed in triplicate and representative of at least 3 independent experiments, mean ± SD) are shown. (B) Percoll-purified human monocytes (106/mL) were incubated with different concentrations of sTat for 10 minutes (○). The reaction was stopped and the percentage of cells with bipolar configuration (front-tail) was determined. Data are expressed as the percentage of increase over control (0%). In the absence of the agonist (control), 23.6% ± 4% (n = 3) monocytes were in the polarized configuration. Results are the mean ± SD of three independent experiments performed in duplicates. In the same experimental conditions, the effect of 10 nmol/L FMLP was 133% ± 19% (n = 3) increase over control. **P < .001; *P < .01 versus control (no rTat) by paired Dunnett's test. The effect of sFlt-1 on rTat-induced polarization was evaluated by preincubating cells with 210 ng/mL for 10 minutes (•). **P < .001 versus sFlt-1–untreated cells. Results of one experiment (performed in triplicate and representative of at least 3 independent experiments, mean ± SD) are shown.
