Replication of human cytomegalovirus in severe combined immunodeficient mice implanted with human retinal tissue

Because human cytomegalovirus (HCMV) infection and replication are limited to human cells, few animal models can be used to specifically examine the b iology of HCMV in vivo. In these studies, fetal human retinal tissue was im planted into the anterior chamber of the severe combined immunodeficient (S CID) mouse eye and subsequently was inoculated with HCMV. Viral replication , localized to glial cells in the xenografts, was first detected 7 days aft er infection. Thereafter, HCMV replication increased to peak levels through days 21-28 and then gradually decreased to undetectable levels by 8 weeks after infection. The clinical isolate Toledo replicated to higher titers th an did strain AD169 or Towne. A comparison of implant age indicated that ol der tissue could support higher levels of HCMV replication than could young er implants. SCID mice implanted with human retinal tissue provide an excel lent model for evaluation of HCMV infection of an ocular structure in vivo.