HLA-DR and -DQ epitopes and monoclonal antibody specificity

The polymorphism of the HLA system-originally studied serologically using antisera from multiparous women and cellularly using the mixed lymphocyte reaction-has now been further revealed by the use of monoclonal antibodies and, at the most basic level, by the nucleotide and amino acid sequences of the different alleles. In this article, Steven Marsh and Julia Bodmer examine the specificity of mainly well-known HLA-DR and HLA-DQ monoclonal antibodies and postulate the positions of their binding sites, or at least of the polymorphic sites determining their patterns of reactivity. The publication together of all available amino acid sequences of the first domain of the DR beta and DQ alpha and the DQ beta chains (updated and corrected where necessary in collaboration with their authors) provides a useful tool with which to identify binding sites of other antibodies and perhaps to attempt to correlate their position in the structure with their function. Outlines of strategies to produce a wider range of polymorphic antibodies are discussed.