A cytotoxic mouse monoclonal antibody UL-52 (IgG2b) was obtained after immunization of a BALB/c mouse with the lymphoblastoid cell line STA homozygous for HLA-A3, B8, Cw7, DR3, DRw52, DQw2, DPw2. Fluorescence analysis on a panel of B lymphoblastoid cell lines from the 10th International Histocompatibility Workshop 1987 showed almost exact concordance of UL-52 reactivity with the presence of the HLA-DRw52 antigen. Cytotoxicity testing of UL-52 on mononuclear cells of HLA-typed individuals revealed a pattern of reactivity closely associated with the HLA-DRw52 specificity as defined by conventional alloantisera (R = 0.77). UL-52 precipitated appropriate 29,000- and 33,000-dalton bands on SDS- polyacrylamide gels under reducing conditions from an HLA-DRw52 positive B lymphoblastoid cell line. Thus, by serological and biochemical criteria UL-52 defines a supertypic determinant associated with HLA-DRw52. In contrast to most DRw52- like monoclonal antibodies, UL-52 binds to DRw8 positive cells.
