IMMUNOPATHOGENIC MECHANISMS OF HUMAN-IMMU NODEFICIENCY-VIRUS INFECTION

Human immunodeficiency virus (HIV) infection usually elicits an early, strong and efficient immune response, despite which;he virus can pers ist in the organism by using a complex strategy. It escapes immune sur veillance through direct and indirect effects on cells of the immune s ystem; by modifying its biological properties; and by antigenic drift as a result of the immune response selective pressure. The immune resp onse to the virus could also lend to detrimental immunopathological me chanisms. 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 p resent 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 me chanisms involved in this infection is thus essential.