A RABBIT MODEL FOR HUMAN CYTOMEGALOVIRUS-INDUCED CHORIORETINAL DISEASE

AD169, a well-characterized laboratory strain of human cytomegalovirus (HCMV), was used to establish an animal model of progressive HCMV cho rioretinal disease by injection of 10(5) pfu into the rabbit vitreous. Chorioretinal, vitreous, and pulmonary disease were monitored by HCMV recovery, clinical observation, antigen localization, and histopathol ogy. Vitritis and focal areas of immune cellular infiltrates were seen in inner retinal layers on days 2-4 after inoculation. Disease progre ssed with more severe vitritis and to involve the outer retinal layers in areas of mixed monocytic cellular infiltrates, retinal destruction , choroidal edema, and congestion. HCMV was recovered from chorioretin al cell sonicate cultures in titers ranging from 10(4) to 10(5) pfu du ring peak disease, and HCMV antigens were detected focally by immunofl uorescence in retinal layers on days 2 and 4 after inoculation. A rabb it model of HCMV chorioretinitis similar to human CMV disease allows i nvestigation of HCMV pathogenesis and new antiviral therapies and eval uation of immune system modulation of the HCMV ocular infection.