Biochemical and molecular analysis of sheep MHC class II molecules

A panel of monoclonal antibodies was used for structural and immunodepletion analysis of sheep MHC class II molecules. The results indicate the antibodies recognize molecules of molecular weight 32-34,000 (alpha chain) and 26-28,000 (beta chain). Immunodepletion analysis indicates that the antibodies may recognize up to four distinct class II molecules some of which are structurally distinguishable using SDS-PAGE. Southern blot analysis using HLA-D region DR, DQ, DP, DO and DZ cDNA probes showed that a number of the cDNA probes hybridized specifically to sheep DNA indicating the presence of closely related genes in sheep. Together the results suggest that the sheep MHC class II region contains distinct MHC class II genes similar to those found in man.