Hybridization between a human epithelial line, infectable by Epstein-Barr virus, and Burkitt lymphoma lines: membrane properties, superinfectability, inducibility and tumorigenicity.

Abstract

The human epithelial line U, which is partially infectable with EBV, was hybridized with the EBV-genome carrying Burkitt lymphoma lines P3HR-1 and Daudi. Authenticity of the hybrids U-Put and U-Dut was established by isoenzyme studies. Although the two hybrids carried the EBV genome derived from the lymphoma parent, being 100% positive for Epstein-Barr-virus-associated nuclear antigen (EBNA), they resembled the U parent in many respects: they were deficient for membrane immunoglobulins and Fc receptors, and had a lower concentration of EBV-C3 receptors than either parent. Unlike the P3HR-1 parent, U-Put hybrid was nonpermissive for both the EBV cycle antigens, early antigen (EA) and viral capsid antigen (VCA). The inducing agent 12-O-tetra-decanoyl-phorbol-13-acetate (TPA) caused distinct viral early antigen synthesis (EA) in U-Put, lower, however, than that of the parental P3HR-1. U-Dut was completely nonpermissive and noninducible for early and viral capsid antigens. Thus, even an epithelial parent infectable by EBV restricted, although not completely, expression of EBV antigens, with the exception of EBNA. It has been suggested that EBNA is an autonomous function of the viral genome, independent of host cell control; the latter regulates expression of antigens related to viral cycle. The hybrids U-Put and U-Dut resembled the U parent also in regard to growth in soft agar and tumorigenicity in nude mice, although in this respect the lymphoma parental properties were not completely eclipsed.