Depletion of autologous B cells in vitro from PBMCs of CLL patients. (A) The percentage of B cells (□) and TCRVγ9⁺ γδ T cells () remaining in the PBMCs of CLL patients (mean ± SD, n = 8) after 1, 7, and 13 days culture in medium supplemented with PAg and therapeutic mAbs, as indicated. Data are means plus or minus SD; NS: no significant change as compared with day 0, Mann-Whitney tests with α = 5%. (B) Amplification of TCRVγ9⁺ γδ T cells from PBMCs of the same CLL patients as in panel A after 13 days culture in medium supplemented with IL2 and the specified reagent; *P < .05 versus “control IL2 medium” by 1-way paired t tests. (C) Cytotoxic degranulation by TCRVγ9⁺ γδ T cells (amplified from patient CLL017 as specified) in response to 4-hour incubation with autologous PBMCs and PAg, as indicated. (D) ⁵¹Cr-release assays for specific lysis of target cells (autologous PBMCs or allogeneic MEC2 CLL, as specified) by CLL patients' PBMCs that were either untreated or activated by 13 days' culture with BrHPP and IL2 as specified. Data are means of triplicates from 1 of 3 experiments. (E,F) Same experiments as in panels C and D with RTX-treated CLL target cells.