Herpes Simplex Virus Latency in Cultured Human Cells Following Treatment with Cytosine Arabinoside

Abstract

Summary Treatment of human cell cultures infected with herpes simplex virus type 2 (HSV-2) with cytosine arabinoside resulted in the prevention of both virus cytopathology and synthesis of detectable infectious virus. Following removal of the inhibitor infectious HSV-2 reappeared and the cultures were destroyed. However, there was a delay of at least 5 to 6 days following inhibitor removal before infectious virus could be detected. The reappearance of infectious HSV-2 was paralleled by virus cytopathology. The period between the disappearance and reappearance of infectious virus is defined as the latent period. Cultures during this period were as sensitive as control cultures to superinfection with HSV-2 or vesicular stomatitis virus. Infectious centre assays performed with cultures during the latent period indicated that as many as 1 in 800 cells were capable of ultimately synthesizing infectious virus. Attempts to prevent the reappearance of infectious HSV-2 by treating infected cultures with cytosine arabinoside for up to 22 days were unsuccessful, thus indicating that HSV-2 can remain associated with the cells in a non-infectious form for an extended period without being degraded.