Detection of latency-associated transcripts of equid herpesvirus 1 in equine leukocytes but not in trigeminal ganglia

Results from Southern hybridization and PCR amplification experiments using a randomly synthesized reverse transcription-PCR product showed that peripheral blood leukocytes from horses showing no clinical signs of disease expressed a putative latency-associated transcript antisense to and overlapping the 3' end of the equid herpesvirus 1 (EHV-1) immediate-early gene (gene 64), A PCR product derived from this transcript has greater than or equal to 96% identity with the published EHV-1 sequence, In situ hybridization studies of equine bronchial lymph nodes corroborated these findings and are consistent with reactivation data (D, A. Smith, A, Hamblin, and N. Edington, unpublished data), indicating that EHV-1 latency is established predominantly in CD5(+)/CD8(+) leukocytes.