Mouse monoclonal antibody detects a new polymorphic Ia determinant other than HLA-DR antigen: a possible allele of DC-1.

Using a hybridoma technique, a monoclonal antibody ( TA10 ) reactive with a new polymorphic B-cell antigen was obtained. The TA10 antibody reacted with 12 (24%) of B cells from 50 healthy individuals, but not with T cells. In contrast with the HLA-DR antigen, the TA10 antigen was preferentially detected on B cells, but not on monocytes. The reactive pattern of TA10 was closely associated with DR5 and its related DR antigen NJ2 , and also found with DR4 or DRw9 . The linkages of TA10 to these DR antigens were confirmed in the family study, indicating that the TA10 antigen is controlled by a closely linked but distinct locus from HLA-DR. Furthermore, two-dimensional gel analysis demonstrated that the TA10 determinant was expressed on a class II molecule whose heavy and light chains were different from those carrying the DR determinant. Thus, this monoclonal antibody might detect an allele of DC-1 which is found in association with DR5 and DRw6.2.