Molecular Polymorphism of DR and DQ Products

Abstract

In an attempt to obtain a molecular localization of determinants on HLA class II products recognized by T lymphocytes (the LD determinants), as distinct from the serologically defined DR/DQ determinants, we have studied DR and DQ β-chains using two-dimensional gel analysis (SDS-PAGE: IEF). Cells used for study of the DR product were homozygous for DR. Our primary focus has been on the DR4 product, of which there are at least five LD/Dw subtypes (Dw4, Dw10, Dw13, Dw14, and Dw15) [1]. Our findings [2, 3], illustrated in Fig. 1, are the following: The IEF position of DR4 β-chains from cells expressing different LD/Dw subtypes varies, showing a correlation between the IEF pattern and the LD/Dw phenotype. Shown in the top of Fig. 1 are IEF patterns for DR4 cells expressing Dw10, Dw4, Dw14, and Dw15, respectively. (DR4-Dw13 β-chains migrate between Dw4 and Dw10, data not shown). No difference was seen in the IEF patterns of Dw4 and Dw14 β-chains, whereas the other DR4-associated LD/Dw sub-types could be distinguished. Differences in IEF patterns were maintained following treatment with neuraminidase [3].

This paper #387 from the Immunobiology Research Center. This work was supported in part by NIH grants # RO1 AI 17687, AI 18326, AI 19007, and 2PO1 AM 13083, the March of Dimes Birth Defects Foundation grants #6-255 and # 1-887, and the National Multiple Sclerosis Society grant # RG 1505-A-1