The HLA-dependent expression of testis-organizing H-Y antigen by human male cells

The proposal that the stable expression of organogenesis-directing plasma membrane antigens, such as testis-organizing H-Y antigen, requires β₂-microglobulin-MHC antigen dimers as anchorage sites was tested on Daudi human Burkitt lymphoma cells [46, XY, 15q-, 14q+, β₂-m(-), HLA(-)]. The H-Y antigen level of Daudi was only 20% of that of Raji and Ramos, two human male pseudodiploid Burkitt lymphoma lines that were β₂-m(+), HLA(+). When Daudi is hybridized with β₂-m(+), HLA(+) cell lines, β₂-microglobulin, supplied by the latter, is known to restore the expression of Daudi HLA antigens A10 and BW17. Such restoration of HLA antigen expression markedly elevated H-Y antigen levels in those somatic hybrids. Thus the H-Y antigen level of the Daudi × Raji 8A (♂ × ♂) hybrid became equal to that of TetraRaji-the colcemide-induced Raji tetraploid line. Two independently derived Daudi × HeLa D98 (♂ × ♀) hybrids, DAD 1 and DAD 10, demonstrated even higher H-Y antigen levels comparable to that of normal male peripheral blood lymphocytes.