The epitope recognized by pan-HLA class I-reactive monoclonal antibody W6/32 and its relationship to unusual stability of the HLA-B27/β 2 -microglobulin complex

• DOI: 10.1007/s002510100353
• Publication Date: 2002-10-06T09:35:24Z
• Authors: Tri Tran; Pavol Ivanyi; Ivan Hilgert; Tomáš Brdička; Marika Pla; Birgitta Breur; Miroslav Flieger; Eva Ivašková; Václav Hořejší
• Keywords: 0301 basic medicine; Protein Denaturation; Macromolecular Substances; Histocompatibility Antigens Class I; Antibodies, Monoclonal; Sodium Dodecyl Sulfate; Cell Line; 3. Good health; Epitopes; Mice; 03 medical and health sciences; HLA-B Antigens; Animals; Humans; beta 2-Microglobulin; Cells, Cultured; HLA-B27 Antigen

A broadly used pan-HLA class I-reactive monoclonal antibody W6/32 is believed to recognize a conformational epitope dependent on association between heavy chains and beta2-microglobulin (beta2m). However, in the present study we report that W6/32 does recognize at least some free HLA class I heavy chains under the partially denaturating conditions of nonreducing Western blotting, namely nearly all HLA-B allelic products. Furthermore, we confirm and largely extend our previous observation that complexes of beta2m with heavy chains of a few HLA class I allelic forms (most notably HLA-B27) exhibit unusual resistance to dissociation by SDS, which is reminiscent of MHC class II molecules. In addition, our data indicate the existence of covalent (disulfide-linked) heterodimers of certain HLA class I heavy chains (namely Cw1 and Cw4) and beta2m.