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Developing and Activated T Cell Survival Depends on Differential Signaling Pathways to Regulate Anti-Apoptotic Bcl-xL.
- Source :
- Clinical & Developmental Immunology; 2012, p1-6, 6p
- Publication Year :
- 2012
-
Abstract
- Survival of T cells in both the central and peripheral immune system determines its ultimate function in the regulation of immune responses. In the thymus, developing T cells undergo positive and negative selection to generate a T cell repertoire that responds to foreign, but not self, antigens. During T cell development, the T cell receptor α chain is rearranged. However, the first round of rearrangement may fail, which triggers another round of α chain rearrangement until either successful positive selection or cell death occurs. Thus, the lifespan of double positive (CD4<superscript>+</superscript>CD8<superscript>+</superscript>; DP) thymocytes determines how many rounds of α chain rearrangement can be carried out and influences the likelihood of completing positive selection. The anti-apoptotic protein BclxL is the ultimate effector regulating the survival of CD4<superscript>+</superscript>CD8<superscript>+</superscript> thymocytes subject to the selection process, and the deletion of Bcl-x<subscript>L</subscript> leads to premature apoptosis of thymocytes prior to the completion of the developmental process. In addition to its critical function in the thymus, Bcl-x<subscript>L</subscript> also regulates the survival of peripheral T cells. Upon engagement with antigens, T cells are activated and differentiated into effectors. Activated T cells upregulate Bcl-x<subscript>L</subscript> to enhance their own survival. Bcl-x<subscript>L</subscript>-mediated survival is required for the generation of effectors that carry out the actual immune responses. In the absence of Bcl-x<subscript>L</subscript>, mature T cells undergo apoptosis prior to the completion of the differentiation process to become effector cells. Therefore, Bcl-x<subscript>L</subscript> ensures the survival of both developing and peripheral T cells, which is essential for a functional immune system [ABSTRACT FROM AUTHOR]
- Subjects :
- T cell receptors
IMMUNE system
IMMUNE response
ANTIGENS
CELL death
Subjects
Details
- Language :
- English
- ISSN :
- 17402522
- Database :
- Complementary Index
- Journal :
- Clinical & Developmental Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 84745467
- Full Text :
- https://doi.org/10.1155/2012/632837