CD40L/OX40L-expressing B-CLL cells elicit increased IFN-γ and granzyme B release by autologous peripheral blood CD4 and CD8 T lymphocytes. (A-B) Number of IFN-γ and granzyme B spots/2 × 10⁴ CTLs, respectively, against the autologous B-CLL target for each different condition tested at week 4 (mean + SD). □ indicates total amount of spots; ▦, number of spots after CD8 blocking; ▪, number of spots after CD4 blocking. ^*Significant difference (P < .05) comparing the CD40L/OX40L combination to each molecule alone or no stimulation. (C) Number of IFN-γ spots/2 × 10⁴ CD40L/OX40L-stimulated CTLs against the autologous B-CLL target and the different control targets (mean + SD). (D) Same experiment as in panel C after CD56 depletion. ^**Significant difference (P < .05) comparing the response against autologous CLL cells with responses against allogeneic CLL cells, autologous PHA blasts, and K562.