RNA complementary to herpes simplex virus type 1 ICP0 gene demonstrated in neurons of human trigeminal ganglia

Recent studies with mice have demonstrated abundant RNA transcripts which are complementary (antisense) to the herpes alpha gene ICP0 in latently infected ganglia. We investigated the situation in unselected human trigeminal ganglia. Strand-specific 2.7-kilobase herpes simplex virus type 1 (HSV-1) ICP0 RNA probes were prepared, and their sense was determined in productively infected cells. Although in situ hybridization demonstrated ICP0 antisense RNA transcripts in the nuclei of neurons in 46% of the ganglia, ICP0 messenger RNA was not found in any of the ganglia. We conclude that HSV-1 antisense ICP0 RNA is present in humans during ganglionic latency.