T-cell homeostasis in HIV-1 infection

Failure of T-cell homeostasis is an important feature of HIV-1 infection. Substantial evidence indicates that T-cell homeostasis is independent of CD4⁺ and CD8⁺ subsets, and this may contribute to the decline of CD4⁺ T cells to low levels in this disease. Moreover, failure of T-cell homeostasis appears to precede the development of clinically-defined AIDS by approximately 1.5 to 2 years and is thus an important milestone in HIV-1 disease progression. We argue that T-cell turnover and depletion of memory cells in HIV-1 infection can be viewed as the reverse of the process by which immune reconstitution occurs after stem cell transplantation, and that changes in the functional level of T-cell memory may be critical to both processes. An understanding of the relationship between T-cell memory and regeneration of lost T cells may help preserve and/or reconstitute immune system homeostasis in HIV-1-infected individuals.