PROPORTIONAL AMPLIFICATION OF INDIVIDUAL HLA-A AND HLA-B ANTIGENS DURING UP-REGULATED EXPRESSION OF TOTAL CLASS-I HLA MOLECULES

Our recent studies demonstrated that each specific HLA-A or -B antigen is not expressed in equal quantity in cells of an individual and that the relative amounts of different HLA-A and -B antigens are genetically predetermined following Mendelian laws, These findings suggest the potential genetic importance of varied quantitative HLA expression on target cells in determining the sensitivity to cytotoxic T lymphocytes. It would be important to know whether the amounts of different HLA antigens ate differentially or proportionally amplified after upregulated expression of total HLA antigens. We have therefore determined the effects of IFN treatment, EBV transformation, and influenza virus infection on the quantitative expression of total HLA antigens and the relative quantities of different specific HLA-A and -B antigens in human fibroblast cell line and peripheral blood mononuclear leukocytes. In contrast to earlier studies using the transfected HLA genes, our results show that different individual HLA-A and -B antigens are proportionally and not differentially amplified during upregulated expression of total class I HLA molecules. This finding indicates that the genetic predetermination of varied quantitative expression of HLA antigens may play a role in influencing antiviral immunity and disease susceptibility.