HLA-DQ1 + DQ3-specific monoclonal antibody cross-reacts with a rat MHC-encoded polymorphic determinant.

From a panel of seven mouse monoclonal antibodies against human class II molecules only one, HL-37, directed against the beta chain of human DQ1 and DQ3 antigens cross-reacted in membrane immunofluorescence with the RT1b haplotype of the rat major histocompatibility complex. From the results obtained using an indirect immunoprecipitation method with 35S- and 125I-labelled rat samples from RT1b-carrying lymph node cells it can be supposed that the rat homologue of the human DQ beta chain was detected.