AML T cells exhibit impaired immunologic synapse formation with healthy APCs in mixed allogeneic experiments. T cells from AML patients or age-matched healthy donors (healthy) were allowed to conjugate with allogeneic (allo) healthy B cells ± sAg acting as APCs (CMAC dyed, blue). Conjugates were then fixed, stained, and scored for F-actin (rhodamine phalloidin, red) polarization at the T-cell immune synapse. Data are the mean ± SD from 10 independent experiments with 50 conjugates analyzed per experiment. Arrows indicate protein localization at the T-cell–APC synapse site. Colocalization of F-actin (red) and phosphotyrosine (P-Tyr, green) in the upper right merge images is shown in yellow. Original magnification × 63. Statistical differences between experimental groups were evaluated by 2-tailed Student t test. P < .05 was considered statistically significant