Can HIV be Cured? Mechanisms of HIV persistence and strategies to combat it.

Stable remission is the ultimate goal of HIV therapy. A review of recent studies on the ability of HIV to persist despite highly active antiretroviral therapy (HAART) and immune stimulation suggests that achieving this goal will require four developments in basic and clinical science. First, more effective antiretroviral therapies, targeted at proteins other than reverse transcriptase and protease, in order to eliminate the cryptic replication that continues despite best available HAART. Second, agents that activate latent HIV gene expression in quiescent CD4 memory T cells, thereby exposing this viral reservoir to therapeutic intervention by a "shock and kill" strategy. Third, molecules such as immunotoxins that specifically recognize HIV-encoded membrane proteins and thereby potentiate the destruction of infected cells. Fourth, and still most distant, novel approaches such as genetically engineered cytotoxic T lymphocytes or anti-HIV microbes to suppress rekindling of infection by residual virus sequestered in anatomical and cellular reservoirs. Although each of these steps will be difficult to achieve, the many benefits of a cure for HIV make this a worthwhile pursuit.