Co-dominance of Isoantigens in Somatic Hybrids of Murine Cells Grown In Vitro2

Abstract

The isoantigenic phenotypes determined by the H-2 complex were investigated in 3 murine cell lines and 5 somatic hybrids resulting from cell fusions in vitro. Red cells from various inbred mouse strains were tested for specific isoagglutination by antisera obtained after immunization of mice with parental and hybrid cells from tissue cultures. These antigenic cells were also used for absorption of known isoantisera in which the remaining hemagglutinating titers were subsequently determined. Consistent co-dominance of several H-2 antigenic components and of 2 new non-H-2 antigens (lota and Kappa) introduced by the parental cells was observed in the somatic hybrids. Persistence of isoantigens over long periods of cell culture in vitro and full antigenic co-dominance in heteroploid hybrids are discussed as indicative of vital functions performed by histocompatibility substances in cell-surface structure and physiology. The findings constitute immunologic evidence for somatic hybridization supporting the previously established coincidence of parental marker chromosomes in the hybrid nuclei.