Induction of natural cytotoxicity receptor expression in γδ PBLs activated with pan–T-cell mitogen. γδ PBLs were cultured as described in Figure 1 for 4-19 days and analyzed by flow cytometry for surface expression of various NK receptors. (A) Results for NKG2D, 2B4 and DNAM-1 in 10-day cultures activated either with HMB-PP and IL-2 (gray) or PHA and IL-2 (black), derived from 6 independent healthy donors. Error bars represent SD (n = 6; P > .05). (B) Expression of NKp30 in the same cultures of (A). FACS plots correspond to cultures derived from 3 individual donors. Percentages refer to NKp30⁺ γδ PBLs. Isotype control staining is presented in supplemental Figure 2A. (C-D) Real-time PCR quantification of Nkp44 (C) and Nkp46 (D) mRNA levels in freshly isolated, HMB-PP and IL-2–activated and PHA and IL-2–activated γδ PBL. (E) Evolution of the percentage of NKp30⁺ cells in the cultures described in (A), analyzed up to day 19. Error bars represent SD (n = 5). Data in this figure are representative of 2 to 4 independent experiments with similar results.