Inhibition of p117 lytic activity by MHC class I–specific antibodies.

Lines represent the mean percentage specific lysis and standard deviations in chromium release assays performed in triplicate with E:T ratios of 25:1, 5:1, and 1:1. Cytotoxic activity of the p117-139–specific T-cell line against the WT1-negative cell line EL-4 (EL-4, WT1 negative); EL-4 pulsed with the peptide p117-139 (EL-4 + p117-139); EL-4 + p117-139 incubated with the isotype control antibody (isotype) (IgG_2a κ isotype standard; Pharmingen); EL-4 + p117-139 incubated with D^b-specific antibody (D^b) (anti-H-2D^b; Pharmingen); EL-4 + p117-139 incubated with K^b-specific antibody (K^b) (anti-H-2K^b; Pharmingen); EL-4 + p117-139 incubated with the I-A^d/b MHC class II alloantigen antibody (I-A^d/b) (anti I-A^db; Pharmingen).