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Requirement for Transforming Growth Factor β1 in Controlling T Cell Apoptosis

Transforming growth factor (TGF)-β1, a potent immunoregulatory molecule, was found to control the life and death decisions of T lymphocytes. Both thymic and peripheral T cell apoptosis was increased in mice lacking TGF-β1 (TGF-β1(−/−)) compared with wild-type littermates. Engagement of the T cell re...

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Detalles Bibliográficos
Autores principales: Chen, WanJun, Jin, Wenwen, Tian, Hongsheng, Sicurello, Paula, Frank, Mark, Orenstein, Jan M., Wahl, Sharon M.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2001
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2193497/
https://www.ncbi.nlm.nih.gov/pubmed/11514601
Descripción
Sumario:Transforming growth factor (TGF)-β1, a potent immunoregulatory molecule, was found to control the life and death decisions of T lymphocytes. Both thymic and peripheral T cell apoptosis was increased in mice lacking TGF-β1 (TGF-β1(−/−)) compared with wild-type littermates. Engagement of the T cell receptor enhanced this aberrant T cell apoptosis, as did signaling through either the death receptor Fas or the tumor necrosis factor α receptor in peripheral T cells. Strikingly, TGF-β was localized within the mitochondria of normal T cells, and the absence of TGF-β1 resulted in disruption of mitochondrial membrane potential (Δψ(m)), which marks the point of no return in a cell condemned to die. This TGF-β–dependent regulation of viability appears dissociable from the TGF-β1 membrane receptor–Smad3 signaling pathway, but associated with a mitochondrial antiapoptotic protein Bcl–XL. Thus, TGF-β1 may protect T cells at multiple sites in the death pathway, particularly by maintaining the essential integrity of mitochondria. These findings may have broad implications not only for T cell selection and death in immune responses and in the generation of tolerance, but also for defining the mechanisms of programmed cell death in general.