Induction of bilateral retinal necrosis in mice by unilateral intracameral inoculation of a glycoprotein-C deficient clinical isolate of herpes simplex virus type 1

Abstract

Herpes simplex virus can cause acute retinal necrosis, a blinding retinal disease in man. A unilateral intracameral inoculation of herpes simplex virus type 1 (HSV-1) in mice induces retinal necrosis primarily in the contralateral eye and provides an experimental model for the disease. Previous studies suggested that a major envelope glycoprotein of HSV-1, glycoprotein C (gC), is required for retinal necrosis. We studied HSV-1 strain TN-1, a gC-deficient clinical isolated from a lesion of herpetic keratitis, for its pathogenicity in mice with an intracameral inoculation of the virus and found that TN-1 could induce severe necrotizing retinitis in both inoculated and uninoculated eyes of BALB/c mice. Inoculation with a lower dose of TN-1 resulted in a unilateral necrotizing retinitis in the uninoculated eyes. Tissue virus titration of infected mice killed at various times after inoculation detected an infectious virus in various organs including the eyeballs, trigeminal ganglia, brain and adrenal glands. Anterior chamber-associated immune deviation (ACAID) was observed in TN-1-inoculated mice as well as in mice inoculated with gC-positive laboratory strain KOS 7 days postinoculation. Our findings suggested that gC of HSV-1 is not necessary for either the induction of retinal necrosis, neural spread of the virus, or ACAID.

Analysis by RNA-PCR of latency and reactivation of herpes simplex virus in multiple neuronal tissues

“…Female 6-to 8-week-old BALB/c mice (Kyushu University Animal Center) were inoculated into the bilateral ocular anterior chamber with 2 x 10 ~ p.f.u. of HSV-1 (strain KOS) per eye, essentially as described (Liu et al, 1993). During the acute phase of infection, three mice were killed at each time point, 1, 3, 5, 7, 10 and 14 days p.i., and tissue samples including the eyes, trigeminal ganglia, brain, spinal cord, adrenal glands, liver, kidneys and spleen were collected for determination of infectious virus (Liu et al, 1993).…”

“…In vivo reactivation of HSV-1 was performed as described by Shimeld et al (1990). Latently infected mice were injected intraperitoneally with 250 mg of cyclophosphamide (Endoxan, Shionogi Pharmaceuticals) per kg followed by 20 mg of dexamethasone phosphate (Decadron, Banyu) per kg, 24 h later (Minagawa et al, 1993). The various tissues of mice were removed at days 1, 2 and 3 following dexamethasone administration, and were then examined as described above.…”

“…Fig. 1 shows the design of RNA-PCR for detection of viral transcripts from extracted RNA (Lynas et al, 1989;Spivack et al, 1991 ;Minagawa et al, 1993). We detected the 2.0 kb LAT (LATu,~puc~d) using primers pLATI0 (5'-ATGGAGCCAGAA-CCACAGTG-3') and pLAT15 (5'-CGCTCGTCTCCTCTGA-TTCTC-3') to amplify a 389 bp fragment (Wagner et al, 1988 a).…”

“…In those mice, HSV-1 induces chorioretinitis (Whittum et al, 1984) and systemic spread of infectious virus was observed during the first 2 weeks post-inoculation (p.i.) (Liu et al, 1993). It has been reported that intracameral infection can cause latent infection in the trigeminal ganglia (Rodahl & Stevens, 1992;Minagawa et al, 1993).…”

“…(Liu et al, 1993). It has been reported that intracameral infection can cause latent infection in the trigeminal ganglia (Rodahl & Stevens, 1992;Minagawa et al, 1993). The latently infected mice post-intracameral inoculation could be useful for studying the mechanisms of latency and reactivation of HSV, in addition to those mice inoculated on the cornea (Spivack & Fraser, 1987;Stevens et al, 1987).…”