Structural Polymorphism of the HLA Class II α and β Chains: Summary of the 10th Workshop 2-D Gel Analysis

A comprehensive analysis of structural polymorphism in the HLA class II antigens has been performed using a standardized two-dimensional (2-D) gel electrophoresis system. Polymorphic patterns have been defined for the α and β chains of the DR and DQ molecules isolated from 71 of the 10th Workshop core B-cell lines representing 34 functionally distinct HLA class II haplotypes. For the DR molecules, a total of 19 DRβ chain patterns were found associated with the DRB1 locus, with 5 additional patterns associated with a second expressed DRB gene. For the DQ molecules, 10 β chain patterns were found along with 9 DQα chain patterns. For the DP molecules, two DPα chain patterns were found, but the DPβ chains were not resolved. This corresponds well to the extent of polymorphism found in the first domain sequences of cloned DR and DQ genes from these haplotypes. While some of the known sequence variation does not result in distinct 2-D gel patterns, additional poly morphism has been found in this study, where first domain sequences are identical.