Persistent Epstein--Barr virus infection in the common marmoset (Callithrix jacchus)

Abstract

Epstein-Barr virus (EBV) infection of the common marmoset causes long-term infection, with production of antibodies to virus-induced antigens, without clinical illness. Attempts to show the presence of EBV DNA in saliva of infected animals by PCR were initially unsuccessful, although slot-blot hybridization analysis demonstrated that viral DNA was present. Further investigations showed that most samples ofpilocarpineinduced saliva, and 33 % of the samples of whole mouth fluids (WMF) tested, were inhibitory to PCR. Similar results were found using human WMF. A method of assessing samples of marmoset WMF for the presence of EBV, by PCR using an EBV BamHI W probe, and removing inhibition with Chelex 100, is described. A total of 202 samples from 21 EBV infected, and seven non-infected animals was tested. Five seropositive animals shed virus on every occasion, and 15 intermittently. Two marmosets, infected as neonates, showed progressively increasing humoral responses to viral antigens, and shed virus on every occasion tested over 3 years. When mated with uninfected animals, the latter seroconverted 4 and 6 weeks later, respectively, and later shed virus into their WMF. The naturally infected animals were paired with naive marmosets, and were able to pass on infection. These results establish that long-term, permissive EBV infection occurs in the common marmoset, and demonstrate again the similarities in the response to EBV between marmoset and man.

Direct demonstration of persistent Epstein-Barr virus gene expression in peripheral blood of infected common marmosets and analysis of virus-infected tissues in vivo.

“…Antibodies to EBV replicative cycle proteins have been reported previously in these infected animals using immunofluorescence tests but no antibodies were found to EBNA 1 (Wedderburn et al, 1984 ;Emini et al, 1986 ;Cox et al, 1996). Antibodies to EBNA 1 are characteristic of long-term persistence of EBV in the normal human carrier.…”

“…Common marmosets were kept and infected with M81 EBV (Desgranges et al, 1976) by injection into Waldeyer's ring as described previously (Wedderburn et al, 1984 ;Cox et al, 1996 ;Mackett et al, 1996). Marmoset 160 (male) was infected with M81 EBV at age 1 month and blood was taken for reverse transcription (RT)-PCR and serology 10 years later.…”

“…In contrast, EBV infection of the common marmoset only very rarely results in spontaneous tumour formation and has been discussed as a model for persistent EBV infection of humans (Wedderburn et al, 1984 ;Cox et al, 1996). Long-term virus persistence has previously been inferred from serology and PCR of virus DNA in saliva , but virus has not been directly demonstrated in the blood.…”

Sustained ex vivo and in vivo transfer of a reporter gene using polyoma virus pseudocapsids

“…Endogenous inhibitory activity was removed from the tissue samples with Chelex 100 (Bio-Rad Laboratories, Hercules, CA, USA) 39 and parallel reactions were carried out with samples to which 10 2 copies of plasmid DNA had been added to control for possible enzyme inhibition. Products, separated by agarose gel electrophoresis, were transferred by Southern blotting to nylon membranes (Biodyne B, Pall, Portsmouth, UK) and probed with 32 P-labelled pCMV␤.…”

Hypothesis: a novel route for immortalization of epithelial cells by Epstein-Barr virus

“…In our earlier work, primary tissues from the common marmoset (Callithrix jacchus) ± a New World primate postulated as a good model for EBV studies (Cox et al, 1996;Farrell et al, 1997;Antunes et al, 1998) ± were used to explore virally-induced cell growth. These primates have chromosomes whose sizes are amenable to analysis and a diploid number of 46 (Ejiwunmi, 1987).…”