NKp30, NKG2D, LFA-1, and DNAM-1 are differently involved in Ag-specific and HLA-unrestricted cytotoxicity exerted by CMV-specific CIK cells. (A-B) CMV-pulsed autologous T–PHA-induced blasts (A) and K562 cell line (B) were analyzed for expression of MICA/B and ULBP-1, -2, and -3 (NKG2D ligands) and PVR and Nectin-2 (DNAM-1 ligands) by flow cytometry. Gray profiles represent isotype control. (C-D) Blocking of activating receptors NKG2D, NKp30, and DNAM-1 in CIK cells cytotoxicity against CMV-pulsed autologous T–PHA-induced blasts (C) and K562 cell line (D) targets. CIK cells preincubated with saturating concentrations of the indicated mAbs were used in calcein-release assays. The results shown are the mean percentage of cytotoxic activity of treated compared with untreated CIK cells. The data were ± SD obtained from 3 independent experiments and were analyzed by Student t test. *P < .05, **P < .01 compared with control in the absence of mAbs.