Spread of HSV and establishment of latency after corneal infection in inbred mice.

The spread of herpes simplex virus (HSV) through neural tissues was studied in three inbred mouse strains that differ in susceptibility to HSV stromal keratitis. The left eyes of BALB/c, C57BL/6, and DBA/2 mice were inoculated topically with HSV type 1. The optic and trigeminal nerves, trigeminal ganglia, and eyes were assayed for infectious virus on days 1, 2, 3, 4, 7, 9, 11 and 14 after inoculation. At 2-4 months post-inoculation, eyes and trigeminal ganglia were assayed for latent virus. Up to 7 days post-inoculation, infectious virus was present at a similar frequency in the inoculated eyes of mice from all three strains. The quantity of virus recovered, however, was mouse strain-dependent: DBA mice yielded the most virus; C57BL/6, the least. The frequency of virus recovery and the quantity of virus recovered from trigeminal nerves and ganglia also varied according to mouse strain. Infectious virus was recovered from the uninoculated right eye of some DBA and C57BL/6 mice 1 wk after inoculation. The overall incidence of latency differed among inbred mouse strains. However, in mice that developed ocular disease (blepharitis, dendritic keratitis, or stromal keratitis), there was no host strain-related difference in the incidence of latency. These results support the hypothesis that host genetic factors play a role in controlling HSV replication and the spread of virus to neural tissues after ocular HSV inoculation. This control may influence the development and severity of disease. However, once infection occurs, latency is established in both susceptible and resistant mouse strains.