Specific cytotoxicity of CD4⁺ T-cell lines.

Specific cytotoxicity of CD4⁺ T-cell lines was restricted by MHC class II. CD4⁺ T-cell lines were tested in standard 4-hour chromium release assays. (A) PD-F4 killed autologous BLCLs and the allogeneic BLCLs sharing DQ0602 (Allo A), but not those sharing DQ0609 (Allo B) or with completely mismatched MHC (Allo C). The cytotoxicity of PD-F4 was inhibited by anti-DQ antibody. (B) ND-R4 was inhibited by anti-DQ, while TD-B4 by anti-DR and anti-DQ antibodies. E-to-T ratio was 3:1. A representative of 2 independent experiments is shown. Error bars represent ± SD.