hCD40L/hOX40L-expressing B-CLL cells efficiently expand autologous T cells. (A) Growth rate of viable autologous T cells stimulated with each different B-CLL target (unmanipulated [•], hCD40L- [▴], hOX40L- [▪], or hCD40L/hOX40L-expressing B-CLL cells []). At each time point, the mean + SD cell number for all 7 donors tested is represented. Cells were counted by trypan blue exclusion. At week 4, no restimulation was performed and no exogenous IL-2 was added. (B) Effect of a CD134/Fc human recombinant protein with hOX40L-blocking activity added to hCD40L/hOX40L-expressing B-CLL cells (• 3 donors tested; mean ± SD) compared with CD40L/OX40L combination (▪) and CD40L alone (). The 3 donors tested in this experiment presented a normal profile of CD4^-CD8^-CD56^- cells.