Figure 7.

Localization of TRAIL receptors into lipid rafts. (a) Flow cytometry analysis of GM3/DR4 or GM3/DR5 association by FRET technique in lymphocytes freshly isolated from a representative HD among six or from two pathological subjects among six affected by B leukemia (Pt1, susceptible, and, Pt2, resistant). Analyses were performed in control cells and in cells treated with perifosine. Numbers indicate the percentage of FL3-positive events obtained in one experiment representative of three. (b) Bar graphs showing evaluation of FE, according to the Riemann's algorithm, of GM3/DR4 and GM3/DR5 association. Results shown represent the mean±S.D. from three independent experiments. Statistical analyses indicated that: (i) GM3/DR4 association was significant in lymphocytes isolated from Pt1 (susceptible to pro-apoptotic stimuli, see Figure 6) but not in lymphocytes from HD and Pt2 (resistant to pro-apoptotic stimuli, see Figure 6) (black columns); and that (ii) GM3/DR5 association was irrelevant either in lymphocytes from HD or from pathological subjects (gray columns). Note different scales. * indicates P<0.05 versus control samples