Modification of Epstein-Barr virus replication by tunicamycin

Abstract

The effect of tunicamycin, which inhibits N-linked glycosylation, on the replication of Epstein-Barr virus was examined. Tunicamycin markedly reduced the yield of virus from producing cells. At concentrations of 1 to 2 jig of tunicamycin per ml, there was a buildup of intracellular virus in P3HR1-CI13 cells but not in MCUV5 cells; at a concentration of 5 jig of tunicamycin per ml in P3HR1-CI13 cells, viral DNA synthesis was inhibited as well. Viral glycoproteins lacking N-linked sugars were apparently inserted into the cell membrane, and the small amount of virus made in the presence of drug was able to bind specifically to its receptor on B cells. However, the ability of the virus to induce immunoglobulin secretion by fresh human lymphocytes was impaired. This implies a role for viral glycoproteins in the penetration as well as the attachment of virus.

Inhibitors of protein glycosylation and glycoprotein processing in viral systems

“…This result resembled much the result obtained in the HSV system, see p. 265 and Table 9 (Spivack et al, 1982;Svennerholm et al, 1982). Moreover, as was found for HSV, such enveloped particles adsorbed to permissive cells at normal rates, when compared to untreated virus, but the ability of attached virus to penetrate the plasma membrane was strongly reduced as a consequence of the tunicamycin treatment (Hutt-Fletcher et al, 1986).…”

“…This finding, the tunicamycin-sensitivity of EBV and HSV penetration, and an immunological cross-reactivity between gB and gp85 suggest that these two glycoproteins perform similar functions, i.e. take part in the penetration of HSV and EBV, respectively (Hutt-Fletcher et al, 1986).…”

“…A detailed picture of the effects of inhibition of formation of N-linked oligosaccharides on the infectious cycle has so far been obtained only for EBV (Hutt-Fletcher et al, 1986). Thus, in the presence of tunicamycin seemingly intact enveloped EBV particles without infectivity are formed.…”

Antigenic cross-reactions among herpes simplex virus types 1 and 2, Epstein-Barr virus, and cytomegalovirus

“…Monolayers of baby hamster kidney cells (BHK-21), Vero cells, and human embryonic fibroblast cells (WI38) were grown in Dulbecco modified Eagle medium (Gibco Laboratories, Grand Island, N.Y.) supplemented with antibiotics and heat-inactivated fetal bovine serum. B lymphoblastoid cell lines were grown in RPMI 1640 medium (Gibco) and included Raji cells (7,21), which carry the EBV genome but do not produce virus; P3HR1-Cl13 cells (7,21), which are an EBV-producing cell line that is superinducible with phorbol esters; MCUV5 cells, a marmoset line that produces a transforming strain of EBV (the latter two lines were a gift of George Miller, Yale University); and BJAB cells (7, 21), which are EBV negative.…”

“…HSV-1 (strain KOS) and HSV-2 (strain 333) were grown and titers determined by plaque assay in Vero cells (3,4); CMV (strain Davis) was grown and titers determined by plaque assay in W138 cells. EBV was concentrated by centrifugation from 7-day spent culture media of MCUV5 or P3HR1-C113 cells that had been induced with 30 ng of 12-0tetradecanoyl phorbol-13-acetate (TPA) per ml (7,21).…”