Role for the microbial translocation in the chronic immune activation and immunodeficiency development during HIV-infection

HIV-infection is a widespread incurable viral disease. The major pathogenetic mechanism for the development of HIV-infection is a violation of the cellular immunity functioning that is associated with progressive depletion of CD4+ T-lymphocytes. The growing immunodeficiency increases the risk for developing malignancies and lethal viral, bacterial, or fungal infections. However, contrary to the accepted belief, the virus itself is not the main cause for the immunodeficiency progression. The massive CD4+ T-lymphocytes death is due to the phenomenon of chronic immune activation. In HIV-positive individuals, a large number of various CD4+ T-cells express activation markers, secrete pro- and anti-inflammatory cytokines, and induce the active phases of the cell cycle. Meanwhile, it is uncontrolled activation that leads these cells to death. The present review briefly discusses the reasons for developing chronic immune activation in HIV-positive patients, including pathologies of the gastrointestinal tract that contribute to the translocation of bacteria and their products into areas under the immune system supervision. It also touches the reasons for death of activated cells in HIV-infection setting. Furthermore, it covers the known ways to controlling the chronic immune activation.