CXCL11-induced F-actin formation in primary human T cells and the effect of inhibitors. At 10, 30, 60, and 300 seconds after 10 nM CXCL11 stimulation, the levels of F-actin were determined by FACS analysis. Significantly lower F-actin levels were found after pretreatment with PTX, U73122, and high concentrations of wortmannin. No effects were observed with the MEK inhibitor U0126 and the inactive analog of U73122 (U73433; data not shown). Data shown are the average of independent experiments with T cells from 7 different donors. Error bars represent SEM. Asterisks indicate values significantly different from CXCL11-induced actin polymerization without inhibitor (Student t test; *P < .05, **P < .005).