Cytotoxic T-lymphocyte responses to HIV-1 reverse transcriptase (review)

Cytotoxic T lymphocytes (CTL) play an important role in the control of huma n immunodeficiency virus (HIV) infection. CTL responses have been demonstra ted for most of the HIV gene products, predominantly gag, pal, and env-enco ded proteins, and also for the regulatory proteins Nef, Tat, Vif, or Rev. T he HIV-1 reverse transcriptase (RT), which derives from expression of the p ol gene, is an important target of cellular immune responses in infected in dividuals. More than 40 different peptides containing RT-specific CTL epito pes have been identified. The most conserved and frequently detected are lo cated in the 'fingers' and 'palm' subdomains of the enzyme, but other epito pes have been found in the 'thumb' and 'connection' subdomains as well as i n the RNase Ii domain. Studies on the sequence variability and functional r ole of amino acids forming CTL epitopes are relevant for addressing importa nt questions relative to viral escape from immune control and the future de sign of anti-AIDS vaccines.