Reversion of CTL escape-variant immunodeficiency viruses in vivo.

摘要: Engendering cytotoxic T-lymphocyte (CTL) responses is likely to be an important goal of HIV vaccines. However, CTLs select for viral variants that escape immune detection. Maintenance such in human populations could pose obstacle vaccine development. We first observed mutations a heterogeneous simian immunodeficiency virus (SIV) isolate were lost upon passage new animals. therefore infected macaques with cloned SIV bearing three immunodominant CTL epitopes, and followed evolution after infection. Here we show each mutant epitope sequence continued evolve vivo, often re-establishing the original, CTL-susceptible sequence. conclude from may exact cost fitness. In absence selective pressure transmission hosts, these original can lost. This suggests some epitopes will maintained populations.