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Cumulative mechanisms of lymphoid tissue fibrosis and T cell depletion in HIV-1 and SIV infections
- Source :
- Journal of Clinical Investigation. March 1, 2011, Vol. 121 Issue 3, p998, 11 p.
- Publication Year :
- 2011
-
Abstract
- The hallmark of HIV-1 and SIV infections is [CD4.sup.+] T cell depletion. Both direct cell killing and indirect mechanisms related to immune activation have been suggested to cause the depletion of T cells. We have now identified a mechanism by which immune activation-induced fibrosis of lymphoid tissues leads to depletion of naive T cells in HIV-1 infected patients and SIV-infected rhesus macaques. The T regulatory cell response to immune activation increased procollagen production and subsequent deposition as fibrils via the TGF-β1 signaling pathway and chitinase 3-like-1 activity in fibroblasts in lymphoid tissues from patients infected with HIV-1. Collagen deposition restricted T cell access to the survival factor IL-7 on the fibroblastic reticular cell (FRC) network, resulting in apoptosis and depletion of T cells, which, in turn, removed a major source of lymphotoxin-β, a survival factor for FRCs during SIV infection in rhesus macaques. The resulting loss of FRCs and the loss of IL-7 produced by FRCs may thus perpetuate a vicious cycle of depletion of T cells and the FRC network. Because this process is cumulative, early treatment and antifibrotic therapies may offer approaches to moderate T cell depletion and improve immune reconstitution during HIV-1 infection.<br />Introduction Depletion of [CD4.sup.+] T cells, the defining characteristic for which the immunodeficiency viruses HIV-1 and SIV were named, has been attributed to direct mechanisms of infection and cell killing [...]
Details
- Language :
- English
- ISSN :
- 00219738
- Volume :
- 121
- Issue :
- 3
- Database :
- Gale General OneFile
- Journal :
- Journal of Clinical Investigation
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.251194724
- Full Text :
- https://doi.org/10.1172/JCI45157