Modulation of CD8 antiviral factor by highly active antiretroviral therapy

Abstract

CD8+ T cells secrete CD8 Antiviral Factor (CAF), an unidentified soluble factor that inhibits replication of HIV-1 by suppression of viral transcription. To date, the effect of Highly Active Antiretroviral Treatment (HAART) on CAF production in HIV+ individuals is inconclusive. Therefore, we have examined CAF production by CD8+ T cells of HIV-positive patients on various treatment regimens, using a transcription-based assay. We found that HAART does not significantly modulate CAF compared to untreated controls, but NNRTI treatment may increase CAF in some patients, as this group demonstrated a higher proportion of effective suppressors of viral gene expression. These trends were not seen at the level of viral replication, which shows that determination of CAF at the level of virus replication does not mirror results found using a transcription-based assay. These results suggest that immunological changes induced by NNRTI-based therapy may affect the ability of CD8+ T cells to produce CAF.