Transforming activity of Epstein-Barr virus obtained by superinfection of Raji cells

Epstein-Barr virus obtained by superinfection of Raji cells with Epstein-Barr virus recovered from P3HR1 cells (HRI virus) transformed human lymphocytes, but it did not superinfect Raji cells. A human lymphoblastoid cell line, HLB, established by such transformation contained 22 Epstein-Barr virus genomes per cell and Epstein-Barr virus-associated nuclear antigen, and a few cells contained early or viral capsid antigen complexes. Chromosomal analysis revealed that HLB-cells were diploid with normal female karyotypes. Replication of Epstein-Barr virus DNA and inhibition of host cell DNA synthesis were observed in HLB cells after superinfection with HR1 virus.