Electrophoretic analysis of HLA-DR2 molecules isolated from HLA-Dw2 and HLA-Dw12 cell lines

To answer the question of whether or not polymorphism exists among HLA-DR2 molecules derived from cells homozygous for HLA-DR2, but expressing different HLA-D specificities, HLA-DR2 molecules were isolated from HLA-Dw2 and HLA-Dw12 homozygous cells using a monoclonal antibody operationally monospecific for HLA-DR2, and were compared to each other by two-dimensional gel electrophoresis. No electrophoretically discernible polymorphism was found in either the heavy or the light chain subunits of the HLA-DR2 molecules. These findings are in marked contrast with previous observations that each of the HLA-DR4-associated HLA-D clusters expresses an electrophoretically distinct HLA-DR4 light chain.