[Immunopathological mechanisms of human immunodeficiency virus infection]

Human immunodeficiency virus (HIV) infection usually elicits an early, strong and efficient immune response, despite which the virus can persist in the organism by using a complex strategy. It escapes immune surveillance through direct and indirect effects on cells of the immune system; by modifying its biological properties; and by antigenic drift as a result of the immune response selective pressure. The immune response to the virus could also lead to detrimental immunopathological mechanisms. In particular, any immune stimulation may increase the viral load, and specific immunisation may lead to enhancement of infection. However, reports that some "at risk" non HIV-infected individuals present markers of cell-mediated immunity to the virus, and occurrence of "long-term survivors" strongly suggests that the immune response to HIV may sometimes be protective. Understanding the immunological mechanisms involved in this infection is thus essential.