Molecular analysis of HLA-DP specificities HLA-DPw1, -DPw2 and -DPw4: DP beta chain heterogeneity correlates with PLT subtyping.

HLA-DP molecules were isolated from Epstein-Barr virus transformed B cell lines by immunoprecipitation with monoclonal antibody B7/21.2 and subsequently analysed by two-dimensional gel electrophoresis. The results obtained demonstrate that the HLA-DP molecules that can be isolated from cells positive for the HLA-DP specificities HLA-DPw1, -DPw2 and -DPw4 display DP beta chain isoelectric point differences, whereas no DP alpha chain polymorphism was observed. These results suggest that the PLT defined HLA-DP specificities (HLA-DPw1, -DPw2 and -DPw4) are probably DP beta chain structures.