Transformation of murine LMTK- cells with purified HLA class I genes. I. Modification of conformation of murine beta 2-microglobulin upon its association with HLA heavy chains.
Murine LMTK- cells were unexpectedly found to cross-react with a murine anti-human beta 2-microglobulin (beta 2-m)monoclonal antibody (m.Ab) after transformation with cosmid clones containing different purified HLA class I genes. The same cross-reactivity was observed with CTP 34 B4 (murine x human) somatic hybrid cells, which express class I molecules constituted of human HLA heavy chains and murine beta 2-m. Inhibition studies of the complement-dependent cytolysis mediated by the cross-reacting m.Ab indicated that isolated murine beta 2-m does not express the cross-reacting determinant, suggesting that its expression by the transformed cells reflects conformational modification of murine beta 2-m upon its association with HLA heavy chains. These results illustrate one of the possible post-translational mechanisms through which the antigenicity of a polypeptide chain can be modified. They might provide a serologic marker of the third domain of HLA class I heavy chains. Finally, because quantitative differences of reactivity with the anti-human beta 2-m m.Ab were observed, depending on the HLA class I genes used for transformation, these results individualize two families of HLA class I heavy chains responsible for different conformational modifications of murine beta 2-m.
D000818:Animals; D001609:Beta-Globulins / Q000276:immunology*; D002462:Cell Membrane / Q000032:analysis; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis; D005455:Fluorescent Antibody Technique; D005802:Genes, MHC Class II; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D006801:Humans; D006822:Hybrid Cells / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011487:Protein Conformation; D011863:Radioimmunoassay; D013045:Species Specificity; D001613:beta 2-Microglobulin / Q000235:genetics / Q000276:immunology*
D001609:Beta-Globulins; D000939:Epitopes; D006680:HLA Antigens; D007143:Immunoglobulin Heavy Chains; D001613:beta 2-Microglobulin