NKp30⁺ γδ PBLs are a stable subset endowed with enhanced cytotoxicity against chronic lymphocytic leukemia cells. NKp30⁺ and NKp30⁽⁻⁾ γδ PBLs were FACS-sorted from 14-day PHA and IL-2–activated cultures. (A) Reanalysis of NKp30 expression in the purified populations. (B) Real-time PCR quantification of Nkp44 (left) and Nkp46 (right) mRNA levels in NKp30⁻ or NKp30⁺ γδ T cells, compared with freshly isolated γδ PBLs. Error bars represent SD (n = 3). (C) Sorted NKp30⁺ γδ PBLs were cultured in the presence of IL-2. Analysis of NKp30, NKp44 and NKp46 expression after 14 days. (D) NKp30⁻ or NKp30⁺ γδ T cells, or freshly isolated γδ PBLs, were used in killing assays with the leukemia cell line Bv173 (as in Figure 1). Tumor cell death was evaluated by annexin-V staining (n = 3, *P < .05). (E) Real-time PCR quantification of GzmB mRNA levels in freshly isolated, NKp30⁽⁻⁾ or NKp30⁺ γδ T cells. Error bars represent SD (n = 3). (F-G) Representative plots (F) and data summary (G) for 5 primary B-cell chronic lymphocytic leukemia samples that were used in killing assays (as in Figure 1) with γδ PBLs obtained from 6 distinct donors and activated with either HMB-PP and IL-2 or PHA and IL-2. NCR(-) γδ PBL from HMB-PP and IL-2–activated cultures (gray bars) were compared with NCR(+) γδ PBL from PHA and IL-2–activated cultures (black bars). Error bars represent SD (n = 6, *P < .05; **P < .01; ***P < .001).