@article{mbs:/content/journal/jgv/10.1099/0022-1317-75-3-647, author = "Minagawa, Hiroko and Tanaka, Shinji and Toh, Yasushi and Mori, Ryoichi", title = "Detection of herpes simplex virus type 1-encoded RNA by polymerase chain reaction: different pattern of viral RNA detection in latently infected murine trigeminal ganglia following in vitro or in vivo reactivation", journal= "Journal of General Virology", year = "1994", volume = "75", number = "3", pages = "647-650", doi = "https://doi.org/10.1099/0022-1317-75-3-647", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-75-3-647", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "Herpes simplex virus type 1 (HSV-1) establishes latent infection in the sensory ganglia. To investigate the process of reactivation from latency, we used the RNA polymerase chain reaction (RNA-PCR) to detect the expression of several HSV genes. BALB/c mice were inoculated in the anterior ocular chamber with HSV-1 strain KOS and the trigeminal ganglia were examined at least 8 weeks after inoculation. Latency-associated transcripts (LATs) were found in the latently infected ganglia and remained detectable 120 h after explantation. Besides LATs, we detected transcripts for infected cell protein 0 (ICPO) (Vmw110) 24 h after explantation, but RNAs encoding ICP4 (Vmw175), ICP27, thymidine kinase and VP16 (ICP25; Vmw65) remained undetectable for 120 h after explantation. Following in vivo reactivation of HSV-1 by administration of cyclophosphamide and dexamethasone, all viral transcripts including ICPO RNA became detectable. The RNA-PCR enabled us to detect ICPO RNA much earlier than has been previously reported in studies using the Northern blot technique and has laid a foundation for further study of viral and cellular transcripts during reactivation. Our results suggest that the process of reactivation of HSV-1 from trigeminal ganglia may be divided into at least two steps: (i) initiation of ICPO gene transcription and (ii) detectable transcription of the other genes. The second step may be regulated in part by the host immune system, since cyclophosphamide and dexamethasone administration enabled the detection of several viral transcripts.", }