ANALYSIS BY RNA-PCR OF LATENCY AND REACTIVATION OF HERPES-SIMPLEX VIRUS IN MULTIPLE NEURONAL TISSUES

Following intracameral inoculation with herpes simplex virus type 1 (H SV-1), BALB/c mice develop acute necrotizing chorioretinitis and infec tious virus is detected in the eyes, trigeminal ganglia, brain, spinal cord and adrenal glands during acute infection. In this study, we ana lysed the latent phase of this experimental animal system. In mice whi ch survived the acute infection, latent HSV-1 was recovered from the t rigeminal ganglia, brain and adrenal glands by cocultivation with Vero cells. In these tissues, both the unspliced latency-associated transc ript (LAT) and the spliced LAT were detected by RNA-PCR. Following in vivo administration of cyclophosphamide and dexamethasone to induce vi ral reactivation, ICP0 mRNA became detectable in the multiple neural t issues, and the spliced LAT disappeared whereas the unspliced EAT rema ined detectable by RNA-PCR. Sequence analysis of the RNA-PCR products revealed that the GC-AG splicing signal previously reported for LATs f rom trigeminal ganglia was also detected in LATs from the brain and ad renal glands, suggesting that the splicing of LATs might be associated with the maintenance of and/or reactivation from latency. The general ized latent infection of HSV-1 described in this study might serve as an experimental model of possible viral reactivation from organs that do not innervate the primary port of entry.