Methylation of the viral genome in an in vitro model of herpes simplex virus latency

摘要: Abstract An in vitro model of latency herpes simplex virus type 1 (HSV-1) a lymphoid cell line has been developed recently. CEM cells persistently infected with HSV-1 transiently ceased to produce for 24 days. This nonproductive state could either be reversed phytohemagglutinin or maintained concanavalin A. system was used study the relationship between DNA methylation and latency. probed by comparing cleavage patterns generated two pairs restriction endonucleases (Sma I vs. Xma Hpa II MspI); these enzymes show differential activity reflecting recognition sequences. Viral A-treated (not producing virus) found extensively methylated. By contrast, no methylated copies were detected viral from producer cells. About 800 days after initial infection, productive culture once again became nonproductive. sequences latter also Reconstitution experiments revealed 1-2 latent stages 40-80 stages. Most (if not all) genome is present various No differences sequence arrangement (although terminal fragment intracellular appeared under-represented cells). These results suggest role mechanism this system.