[HIV-1 infection: pathogenesis of immune suppression]

Although, in the course of HIV-1-infection, the functional capacities of virtually all immune cells are greatly impaired, only CD4+ cells (antigen-presenting cells, helper T cells) are directly infected by the virus. CD4+ T cells are involved, to a greater or lesser degree, in the induction of virtually all immunologic phenomena, either directly or indirectly. Thus, it is clear that the HIV-1-induced depletion and functional impairment of this critical T cell subset will result in a dysfunction/deficiency of the entire immune system and, finally, in the development of opportunistic infections and neoplasms.