HERPES-SIMPLEX VIRUS-DNA IN NORMAL CORNEAS - PERSISTENCE WITHOUT VIRAL SHEDDING FROM GANGLIA

Herpes simplex virus type 1 (HSV-1) DNA has been shown to persist in t he cornea not only after inoculation of experimental animals but also in surgical samples from patients with herpes keratitis. The further o bservation of corneal HSV-1 DNA in subjects without known HSV eye dise ase prompted the present study of the presence and distribution of HSV -1 in eye bank corneas. Prior to DNA extraction, the corneas were trep hined, separating the central and peripheral cornea. With polymerase c hain reaction (PCR) for HSV-1 thymidine kinase (TK) and glycoprotein D (gD) gene sequences, we found HSV-1 in 10 of 24 eye bank corneas, fro m the 4 mm wide corneal rim in 8 eyes and from the 8 mm diameter centr al cornea in 2 eyes. In 9 subjects, both eyes were assayed, and HSV-1 was detected in 6 subjects. In only one subject was HSV-1 detected in both eyes and in only one subject was HSV-1 detected in the central an d peripheral cornea of the same eye. The biological role of HSV-1 DNA corneal sequences is unknown. To investigate this, a rabbit animal mod el was established by transplantation of corneas containing viral DNA sequences in HSV-1 naive recipients. Followed for 5 months, there was no evidence of shedding of HSV-1 in the tear film or seroconversion of the recipient rabbits. At the end of this time, HSV-1 DNA was detecte d in the corneal graft at a similar intensity to the PCR signal from t he donor rims. These results support the view that viral shedding from latently infected ganglia is not necessary for the persistence of cor neal HSV-1 sequences. (C) 1995 Wiley-Liss, Inc.