Herpes simplex virus type 1 latency in rabbit corneal cells in vitro: reactivation and recombination following intratypic superinfection of long term cultures.

Herpes simplex virus type 1 (HSV-1) has been isolated from explanted human corneas after cultivation in vitro. To determine whether HSV-1 is persistent or latent in corneal cells, a system to study HSV-1 infection of rabbit corneal cells in vitro was developed. By elevation of the incubation temperature to 42 degrees C before and during HSV-1 infection it was shown that both keratocytes and epithelial cells support a nonproductive rather than a productive infection. On subsequent temperature reduction to 37 degrees C, infectious virus was released from both cell types. Addition of the viral inhibitor acycloguanosine during the last 5 days of a 14 day incubation at 42 degrees C did not reduce the frequency of viral shedding following transfer to 37 degrees C, indicating that corneal cells support a latent as opposed to persistent infection. Cultures which failed to shed virus spontaneously up to 29 days post-inoculation were superinfected at 37 degrees C, with an XbaI site deletion mutant of HSV-1. Restriction endonuclease analysis of progeny identified both the initial infecting virus and recombinants between the parental and superinfecting genomes.