tailieunhanh - Báo cáo y học: "HIV infection of thymocytes inhibits IL-7 activity without altering CD127 expression"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: HIV infection of thymocytes inhibits IL-7 activity without altering CD127 expression. | Young and Angel Retrovirology 2011 8 72 http content 8 1 72 RETROVIROLOGY SHORT REPORT Open Access HIV infection of thymocytes inhibits IL-7 activity without altering CD127 expression Charlene D Young1 2 and Jonathan B Angel1 2 3 Abstract Background Thymic function is altered in HIV infection and characterized by dysregulation of the thymic epithelial network reduced thymic output and ultimately an impaired naive T-cell pool. The IL-7 IL-7 receptor IL-7R signalling pathway is critical for the maturation and differentiation of thymocytes. HIV infection is associated with a decrease in IL-7Ra CD127 expression and impaired CD127 signalling in circulating CD8 T-cells however little is known about the effect of HIV on CD127 expression and IL-7 activity in the thymus. Therefore the effect of in vitro HIV infection on CD127 expression and IL-7-mediated function in thymocytes was investigated. Findings In vitro HIV infection of thymocytes did not affect CD127 expression on either total thymocytes or on single positive CD4 or single positive CD8 subsets. However HIV infection resulted in a decrease in the level of IL-7-induced STAT-5 phosphorylation and Bcl-2 expression in unfractionated thymocytes. Conclusion These findings indicate that HIV infection alters IL-7 responsiveness of thymocytes by a mechanism other than CD127 downregulation and potentially explain the disruption in thymopoiesis observed in HIV infection. Findings Human immunodeficiency virus HIV infection is characterized by a loss of CD4 T-cells and a progressive loss in cytotoxic T-cell lymphocyte CTL function resulting in immunodeficiency. HIV infection has also been associated with impaired thymic output 1 . Examination of the thymus of HIV-infected pediatric patients reveals selective thymocyte depletion and disruption of the thymic microenvironment which is thought to contribute to more rapid progression to AIDS 2-4 . In HIV-1 infected SCID-hu Thy Liv mouse models there is a .