Apoptotic cell death and cytokine dysregulation in human immunodeficiency virus infection: pivotal factors in disease progression.
The progressive loss of CD4 T lymphocyte is patognomonic of Human Immunodeficiency Virus (HIV) infection and results in immunodeficiency and the appearance of acquired immunodeficiency syndrome (AIDS)-defining pathologies. Although a percentage of CD4 T lymphocytes is destroyed directly by HIV infection, a much higher proportion of lymphocytes remains uninfected and therefore must be destroyed by mechanisms not directly involving viral infection. One such mechanism is apoptotic T cell death (ATCD). ATCD in HIV infection has been shown to be: 1) secondary to cross-linking of CD4 by viral proteins; 2) mediated by both APO-1/Fas and lymphotoxin (LT); and 3) differentially modulated by type 1 and type 2 cytokines. We will briefly analyze the experimental evidences suggesting that ATCD contributes significantly to the immunopathogenesis of HIV/AIDS via depletion of CD4+ T cells.
Clerici
M
M
Universita' degli Studi di Milano, Padiglione L.I.T.A., Ospedale L. Sacco, Via G.B. Grassi, 74, 20154, Milan, Italy. mago@imiucca.csi.unimi.it
Sarin
A
A
Henkart
P A
PA
Shearer
G M
GM