DNA analysis of histocompatibility antigens: identification of new DQw specificities and of DPw patterns

RESUMO

The HLA-D region of the major histocompatibility complex has several subregions, the most important of which are DR, DQ and DP. The genes coding for the beta chains of these proteins present most of the polymorphisms which result in the large variety of class II antigens observed. We have studied the restriction fragment length polymorphism (RFLP) of the DQ beta and DP beta genes in order to establish accurate typing patterns. The data show that DQ typing based on RFLP permits the identification of the recently described DQw1 splits (new antigenic specificities), DQw5 and DQw6. The TA 10-monoclonal antibody-positive split of DQw3, designated DQw7, is associated with specific DNA fragments after digestion with four different enzymes Taq I, Hind III, Pvu II and Bg1 II. Furthermore, the recently reported specificity DQw4 (formerly typed as a blank) is associated with a specific 2.4-kb fragment when the DNA is digested with EcoRV. DP typing proved to be more difficult even though six enzymes were used, and only broad groups could be identified