Antagonistic activity of selected peptides on polyclonal HA-1–specific CTL lines.

Peptides were incubated with ⁵¹Cr labeled, HA-1– expressing EBV-BLCL at 37°C with the indicated peptide concentrations 30 minutes before the addition of the indicated CTL in standard 4-hour⁵¹Cr release assays. Percentage inhibition of lysis by antagonist peptides was calculated as described in “Materials and methods.” Data are representative of at least 2 independent experiments in which the mean percentages lysis of HA-1⁺target cells without antagonistic peptides were 35% for A2Bx, 54% for P.1.1, and 58% for K.1.1.