[Immunologic and viral mechanisms implicated in HIV infection: the impact of treatment]

HIV-infection leads to the destruction of the immune system, mainly of the subgroup of CD4 lymphocytes. The main cell surface receptor for the VIH is the CD4 molecule. However the virus can penetrate into the cell through the CCR5 chemokine receptor that represents a new avenue for antiviral therapy. The early phase of HIV infection is characterised by an active viral replication mainly in lymph nodes. During the development of the infection, persistent viral replication leads to the destruction of CD4 lymphocytes and inhibits their turnover. Highly active antiretroviral therapy inhibits viral replication but can not eradicate the virus. However this treatment can efficiently restore immune function and allows to avoid opportunistic infections. Antiretroviral therapy could be associated with an immunotherapy (interleukin-2, therapeutic vaccination) in order to achieve a more satisfying T-cell specific response directed against the virus, which appears to be lost early in the course of the disease, except in the subgroup of patients with a low progression of the disease.