CD8+ cell noncytotoxic anti-human immunodeficiency virus response inhibits expression of viral RNA but not reverse transcription or provirus integration

Abstract

CD8+ T cells from human immunodeficiency virus (HIV)-infected individuals can suppress HIV replication in CD4+ cells by a noncytotoxic mechanism that inhibits the expression of viral RNA. The present study examined whether other step(s) in the virus replicative cycle could be affected by the CD8+ cells. Culturing HIV-infected CD4+ T cells with antiviral CD8+ T cells did not significantly reduce the amounts of (i) early HIV DNA reverse transcripts (detected by LTR-U3/R), (ii) total nuclear HIV gag DNA, or (iii) integrated proviral DNA. However, exposure to the CD8+ T cells did cause a reduction in the amount of multiply spliced tat and full-length gag mRNA expressed by the infected CD4+ T cells, confirming previous observations. The levels of glyceraldehyde-3-phosphate dehydrogenase and interleukin-2 receptor-α mRNA were not affected. The results support the conclusion that the noncytotoxic anti-HIV response of CD8+ T cells, demonstrable in vitro, does not affect any of the virus replication steps leading to the integration of proviral HIV, but specifically interrupts the expression of viral RNA.