Attempts to induce interferon production by IdUrd induction and EBV superinfection in human lymphoma lines and their hybrids.

Inducers of the Epstein-Barr virus (EBV) cycle, 5-iodo-2-deoxyuridine (IdUrd), phorbol myristate acetate (TPA) and sodium butyrate were tested for their ability to induce EBV-determined antigens, early antigen (EA) and virus capsid antigen (VCA), and to stimulate interferon (IF) production in a variety of EBV-carrying lymphoid cell lines. IdUrd and TPA induced IF production to various extents in the different lines, whereas sodium butyrate did not. There was no relationship between induction of the EBV cycle and production of IF; the two appear to be independent characteristics. Superinfection with the transforming B95-8 virus substrain of EBV induced IF production, whereas superinfection with the abortively cytopathic, non-transforming P3HR-1 substrain had little or no IF-inducing effect, in spite of its highly potent effect on virus antigen (particularly EA) synthesis. Analysis with specific antisera against IF showed that IF preparations produced by three different lymphoid cell lines in response to IdUrd treatment were composed of a mixture of the Le and F antigenic types, with the latter forming a minor species. In contrast, no detectable F interferon was present in spontaneously produced IF preparations from Namalwa cells, or after induction with B95-8 virus.