Effect of adenine arabinoside on Epstein-Barr virus in vitro.

The effect of adenine arabinoside (ara-A) on Epstein-Barr virus (EBV) in cultures of lymphoid cells was examined with use of an EBV-producing cell line, P3HR-1, and a nonproducing cell line, Raji. The presence of EBV-associated viral capsid antigen (VCA) and early antigen (EA) was detected by indirect immunofluorescence. Ara-A inhibited the expression of VCA in P3HR-1 cells at concentrations fivefold below those that inhibited cell multiplication; there was no concomitant accumulation of EA. Ara-A did not inhibit superinfection of Raji cells with EBV and did not induce EA until high concentrations of the compound were reached. The inhibition of the expression of VCA but not EA is consistent with a postulated inhibition by ara-A of viral-directed synthesis of DNA. At low concentrations, ara-A may exert a more specific antiviral effect than that reported for idoxuridine and cytosine arabinoside in this system.