Immunoglobulin production by a human-mouse somatic cell hybrid

The fusion of human lymphocytes and TEPC-15 mouse myeloma cells, which had not been adapted to culture, resulted in the establishment of in vitro hybrid cell cultures. Ten clones of this somatic cell hybrid were examined. There was preferential exclusion of human chromosomes: between two and five human chromosomes were identified in the hybrid clones by Giemsa banding. All of the clones had the mouse parental histocompatibility antigens, but only four clones also retained the human parental histocompatibility antigens. Secretion of parental immunoglobulin was determined by SDS-gel electrophoresis of species-specific immune precipitates. Synthesis of parental immunoglobulin by individual hybrid cells was determined by double label fluorescent antibody staining. Individual cells from six of the clones secreted and synthesized both human and mouse parental immunoglobulins. Three clones secreted only one parental immunoglobulin. Cells from one of these clones secreted and synthesized only human immunoglobulin. Cells from the remaining two clones secreted only one parental species of immunoglobulin but synthesized both human and mouse immunoglobulins. Finally, one clone did not secrete immunoglobulin, yet the individual cells synthesized both human and mouse parental species of immunoglobulin.