Functional role of CD3/TCR and NK cytotoxic activating receptors on CIK cells. (A) Expression of activating receptors NKG2D, DNAM-1, NKp30, NKp46, and NKp44 on CIK cells was analyzed by flow cytometry. Gray profiles represent isotype controls. (B) Redirected killing assay was performed with the use of CIK cells treated with indicated agonist mAbs or without mAbs and calcein-labeled P815 cells. The data were mean ± SD obtained from 3 independent experiments. (C) CIK cells were triggered with P815 cells loaded with different mAbs and then assayed for degranulation by cell surface staining for the lysosomal markers CD107a. The data were mean ± SD obtained from ≥ 3 independent experiments and were analyzed by Student t test; *P < .05, ***P < .005 compared with control in the absence of mAbs.