Appearance of Epstein-Barr virus-determined nuclear antigen in human epithelial cells following fusion with lymphoid cells.

When human epithelial FL cells were fused with lymphoid cells harboring Epstein-Barr virus (EBV) genome, EBV-determined nuclear antigen (EBNA) immunofluorescence became evident in high frequency in FL nuclei of heterokaryons several days after fusion. The implications of the findings are discussed in relation to the presence of EBV genome in nasopharyngeal carcinoma cells.