Characterization of a monoclonal antibody recognizing a monomorphic determinant of the alpha chain of class II DQ antigens.

We have characterized a monoclonal antibody (L2) specific for a determinant of Human DQ class II antigens. After immunoprecipitation and immunofluorescence analysis performed on a panel of DR homozygous cell lines and HLA deleted mutants, it behaves like a monomorphic anti-DQ reagent and does not react with the products of the various DR alleles. On immunoblotting, it reacts with an epitope of the DQ alpha chain.