COMPLEXITY OF THE BOVINE MHC CLASS-II SPECIFICITY DW3 AS DEFINED BY ALLOANTISERA

Alloantisera related to the bovine major histocompatibility complex (M HC) class-II specificity Dw3 were investigated by cross-absorption exp eriments and by application of the monoclonal antibody-specific immobi lization of lymphocyte antigen assay (MAILA). The absorption study rev ealed antibodies specific for an antigenic determinant shared by all D s03 (Dw3)-positive animals, and several other antibody populations rec ognizing the locally defined specificites Ds10, Ds11 and Ds15, that ar e closely associated with Ds03. The results of the MAILA-assay indicat e that the Ds03 specificity is probably encoded by DQ, whereas specifi cities Ds10 and Ds11 are more closely associated with DR molecules. Th e data presented here provide the first evidence that bovine DR and DQ specificities can be identified separately by serological methods usi ng alloimmune antisera.