Isolation and long-term culture of primary ocular human immunodeficiency virus type 1 isolates in primary astrocytes

Vitreous specimens from 14 HIV-1 infected persons undergoing medically indicated vitrectomy were assayed for the presence of infectious HIV-1 and viral tropism. Human primary fetal astrocytes, adult lymphocytes, or macrophages were exposed to vitreous in culture and cells were then assayed for HIV-1 DNA by polymerase chain reaction amplification. We found that 11 of 14 patients tested carried ocular HIV-1 which replicated in one or more primary cell types; of the 13 vitreous samples tested in astrocytes, eight contained transmissible HIV-1. The three patients with no culturable ocular virus were in antiviral therapy at the time of vitrectomy. Comparison of envelope V3 sequences from astrocytes infected in culture to that in uncultured blood cells revealed 21% sequence divergence indicating that ocular HIV-1 transmitted to astrocytes was not recently derived from virus present in the blood. Two ocular samples transmissible to astrocytes were tested further and found capable of sustained replication by serial passage to uninfected astrocytes. However, the viral structural proteins produced by infected astrocytes were abnormal, p24 was absent and higher molecular weight Gag proteins were present. We conclude that the eye is a central nervous system compartment which frequently contains HIV-1 capable of replication in human astrocytes.