Epstein-Barr Virus Replication in Interferon-treated Cells

The Burkitt's lymphoma-derived cell line Daudi is latently infected with the Epstein-Barr virus (EBV). These cells are very sensitive to the growth inhibitory and differentiation-inducing effects of human interferon-α (IFN) and we have examined the possibility that these responses are due to induction of EBV replication. Our results indicate that only a very small proportion of cells (<0.3%) are induced by IFN treatment to express EBV lytic genes at the RNA or protein level, whereas cell growth inhibition is complete under the same conditions. In contrast, when EBV replication is chemically induced the large increase in lytic gene transcripts, including that of the BZLF1 trans-activator gene, is partially inhibited by concomitant IFN treatment. The increase in viral DNA copy number in chemically induced Daudi cells is also partially inhibited by IFN but no effect of IFN on the level of viral DNA is observed in uninduced cells.