Cell mediated cytotoxicity against HLA-D region products expressed in monocytes and B lymphocytes. III. Inhibition by monoclonal antibodies and study of an HLA-B/DR recombinant.

Attempts to further define the antigens recognized by HLA-D-region specific cytotoxic lymphocytes were undertaken using monocytes and transformed B cell lines as target cells. Monoclonal antibody against framework determinants of HLA-DR antigens partially blocked cell mediated lysis, suggesting that at least a portion of the D-region specific cytotoxic cells recognized the HLA-DR determinants. The study of a family with an HLA-B/DR recombinant showed that the determinants recognized by allogeneic anti-HLA-D-region cytotoxic lymphocytes are encoded outside of HLA-B. In addition, cytotoxic lymphocytes specific for the HLA-D region could be generated with cells identical throughout the interval from HLA-A to B and disparate only to the left of HLA-B.