DNA restriction fragment length polymorphism of HLA-DR2: correlation with HLA-DR2-associated functions.

HLA-DR2 can be divided into at least 3 distinct HLA-D clusters which correlate with structural differences within the HLA-D region. Further, a functional counterpart of this subdivision has been previously identified. The presence of a particular DR beta 2 polypeptide chain correlated precisely with the susceptibility of measles virus-infected HLA-DR2 homozygous typing cell lines to lysis by measles virus-specific, HLA class II-restricted CTL clones. To determine if a genetic basis for these functional differences could be detected, the degree of polymorphism at the DNA level within the serologically defined HLA-DR2 haplotype has been examined. By using DNA probes for DR beta and DQ beta 4 of the 5 HLA-D clusters of HLA-DR2 could be distinguished and a RFLP pattern was identified which correlates with known immunological functions associated with these various D types. In addition, this technique of 'molecular genotyping' was used to investigate a limited panel of patients with multiple sclerosis (MS) who were HLA typed as either HLA-DR2,2 or HLA-DR2,blank. The RFLP profile of the HLA-DR2 Dw2 D type was found in all of these MS patients.