Figure 9. Assessment of sensitivity to NK cell-mediated cytotoxicity.

(A) Cytotoxic activity of NK effector cells on YAC-1 and RM-1 target cells was determined by a ⁵¹Cr-release assay at indicated E:T ratios. Target cells used were YAC-1 (•), RM-1 parental (▾), RM-1 parental cells pre-treated by infection with Ad5-IFNγ (▪), RM-1-PSMA clone 3 cells (⧫), or RM-1-PSMA clone 3 cells pre-treated by infection with Ad5-IFNγ (▴). Each data point represents the mean ± standard error of four replicate wells. (B) Flow cytometry analysis of YAC-1 and RM-1 cells stained with PE labeled anti-H60, anti-MULT-1, or anti-Rae-1 antibodies or with an isotype-matched control antibody. Numbers below the histograms correspond to mean fluorescence intensity of each peak.