T-CELLS IN THE UNINJECTED EYE AFTER ANTERIOR-CHAMBER INOCULATION OF HERPES-SIMPLEX VIRUS TYPE-1

PURPOSE. To investigate T cell infiltration in the posterior segment o f the uninjected eye after uniocular anterior chamber inoculation of H SV-1. METHODS. The anterior chamber of one eye of euthymic BALB/c mice was injected with 1 x 10(4) plaque-forming units (PFU) to 2 x 10(4) P FU of herpes simplex virus type 1 (HSV-1; KOS strain). All mice were e xamined for retinitis on day 8 postinoculation (p.i.). Only mice with retinitis were retained and used in these experiments. Animals were ki lled on days 9, 11, 14, 21, 35, and 63 p.i. The uninjected eyes were r emoved. Some of the uninjected eyes were sectioned and stained for CD4 (+) and CD8(+) cells using the avidin-biotinylated enzyme complex meth od. Infiltrating cells were collected from the remaining uninoculated eyes and stained using rat anti-mouse monoclonal antibodies specific f or CD4(+) or CD8(+) T cells, and the percentage of CD4(+) and CD8(+) T cells was determined by now cytometry. RESULTS. At day 9 p.i. (acute retinitis), T cells were observed in the uvea but not in the retina of the contralateral eye. CD4(+) and CD8(+) cells were observed in the s ensory retina coincident with the onset of retinal necrosis (day 11 p. i.), and CD4(+) and CD8(+) T cells continued to be detected in the rem nants of the retina up to and including day 63 p.i. The maximum percen tage of both CD4(+) and CD8(+) T cells was observed at day 21 p.i. CON CLUSIONS. These results demonstrate that T cells enter the retina of t he uninoculated eye during HSV-1 infection. The observation that T cel ls arrive in the sensory retina at the onset of retinal necrosis and n ot during acute retinitis and the peak of virus replication provides f urther evidence that T cells play a role in development of retinal nec rosis. The result that T cells are observed in the uninjected eye as l ate as day 63 p.i. suggests that T cells might also hare a role in the resolution phase of the disease.