Although the brain is an important target for the human immunodeficiency virus type 1 (HIV) and viral infection causes neuronal degeneration and dementia, the mechanisms responsible for HIV transcription in neuronal cells are largely unknown. We show here that retinoic acid (RA) stimulates HIV transcription in human neuronal SH-SY5Y cells. The steroid receptor coactivator 1 (SRC-1) enhances the transcriptional response to RA, and the viral protein Tat cooperates with RA and SRC-1 to induce a strong transactivation. These results suggest that retinoid receptors could play an important role as activators of viral gene expression in the human brain.
