title: Acquisition of HLA class I W6/32 defined antigenic determinant by heavy chains from different species following association with bovine beta 2-microglobulin.
abstract: Murine, rat, rabbit and guinea pig class I heavy chains, which do not react with W6/32 monoclonal antibody when they are expressed in association with autologous beta 2-microglobulin (beta 2-m), can acquire such a reactivity once they are expressed at the surface of cells cultured in conditions which allow their association with bovine beta 2-m. Sequence comparison of beta 2-ms suggests that glutamine at position 89 might be critical for the induction of the W6/32 defined antigenic determinant. However, in the murine species, certain class I heavy chains, in spite of their association with bovine beta 2-m, do not express this determinant. Using genetically engineered hybrid class I molecules and selected congenic strains of mice this negative property was shown to be related to the presence of a cysteine residue at position 121 which allows covalent association of beta 2-m to class I heavy chains (Bushkin, Y., J-S. Tung, A. Pinter, J. Michaelson, and E. A. Boyse. 1986. Unusual association of beta 2-microglobulin with certain class I heavy chains of the murine major histocompatibility complex. Proc. Natl. Acad. Sci. USA 83:432). Therefore, expression of the W6/32 defined antigenic determinant implicates both the beta 2-m and the second domain of the heavy chain, but its expression (or exposure) is prevented by the covalent fixation on cysteine 121 of the light chain.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D003545:Cysteine; D000939:Epitopes; D006168:Guinea Pigs; D006183:H-2 Antigens / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D011817:Rabbits; D051381:Rats; D013045:Species Specificity; D013329:Structure-Activity Relationship; D001613:beta 2-Microglobulin / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006183:H-2 Antigens; D006680:HLA Antigens; D046911:Macromolecular Substances; D001613:beta 2-Microglobulin; D003545:Cysteine