HIVInducedTCellApoptosis

HIV infection is associated with immunosuppression caused by a dramatic reduction in the helper T cell population. The loss of helper T cells may be caused by HIV-induced apoptosis of both infected and uninfected helper T cells. HIV uses the CCR5 chemokine receptor as a coreceptor for macrophage cell entry and upregulates fas-ligand on these cells. CD4 on helper T cells is essential for viral cell entry and infection. Cross-linking of CD4 on the T cell surface may be involved in upregulation of Fas and sensitization of T cells to apoptosis induced by the Fas/Fas-ligand interaction.

Contributor: Glenn Croston, PhD.

REFERENCES: Badley, A.D. et al. (1996) Upregulation of Fas ligand expression by human immunodeficiency virus in human macrophages mediates apoptosis of uninfected T lymphocytes. J. Virol. 70(1):199-206 Desbarats, J., Freed, J.H., Campbell, P.A., Newell, M.K. (1996) Fas (CD95) expression and death-mediating function are induced by CD4 cross-linking on CD4+ T cells. Proc. Natl. Acad. Sci. U.S.A. 93(20):11014-8 Dockrell, D.H. et al. (1998) The expression of Fas Ligand by macrophages and its upregulation by human immunodeficiency virus infection. J. Clin. Invest. 101(11):2394-405