AIDS: a disease of impaired Th-cell renewal?

Individuals who are infected with human immunodeficiency virus (HIV) and develop AIDS are characterized by the progressive loss of T helper (Th) cells, together with an increase in virus load. Despite a remarkable similarity to humans, and their susceptibility to persistent HIV-1 infection, chimpanzees have a relative resistance to the development of AIDS. Here, Jonathan Heeney proposes that the critical underlying event perpetuating the progression to AIDS is the impairment of the immunological microenvironment necessary for competent, antigen-specific, Th-cell renewal. Survival is dependent on the host's ability to preserve the immunological infrastructure sufficiently in order to maintain the capacity for renewal of a balanced, competent Th-cell population.