Thymosin α1 activates dendritic cell tryptophan catabolism and establishes a regulatory environment for balance of inflammation and tolerance
Open Access
- 1 October 2006
- journal article
- Published by American Society of Hematology in Blood
- Vol. 108 (7), 2265-2274
- https://doi.org/10.1182/blood-2006-02-004762
Abstract
Thymosin α1 (Tα1), a naturally occurring thymic peptide, primes dendritic cells (DCs) for antifungal T-helper type 1 resistance through Toll-like receptor 9 (TLR9) signaling. As TLR9 signaling also activates the immuno-suppressive pathway of tryptophan catabolism via indoleamine 2,3-dioxygenase (IDO), we examined Tα1 for possible induction of DC-dependent regulatory effects. Tα1 affected T-helper cell priming and tolerance induction by human and murine DCs and induced IDO expression and function in the latter cells. IDO activation by Tα1 required TLR9 and type I interferon receptor signaling and resulted in interleukin-10 production and generation of regulatory T cells. In transfer experiments, functionally distinct subsets of differentiated DCs were required for priming and tolerance to a fungal pathogen or alloantigens. In contrast, Tα1-primed DCs fulfilled multiple requirements, including the induction of T-helper type 1 immunity within a regulatory environment. Thus, instructive immunotherapy with Tα1 targeting IDO-competent DCs could allow for a balanced control of inflammation and tolerance.Keywords
This publication has 48 references indexed in Scilit:
- Transferring functional immune responses to pathogens after haploidentical hematopoietic transplantationBlood, 2005
- Type I interferon dependence of plasmacytoid dendritic cell activation and migrationThe Journal of Experimental Medicine, 2005
- Regulatory T cellsTransplantation and Cellular Therapy, 2005
- Antitumor Activation of Peritoneal Macrophages by Thymosin Alpha-1Cancer Investigation, 2005
- Human bone marrow stromal cells inhibit allogeneic T-cell responses by indoleamine 2,3-dioxygenase–mediated tryptophan degradationBlood, 2004
- In Vitro–expanded Antigen-specific Regulatory T Cells Suppress Autoimmune DiabetesThe Journal of Experimental Medicine, 2004
- Thymosin α 1 activates dendritic cells for antifungal Th1 resistance through Toll-like receptor signalingBlood, 2004
- Role of plasmacytoid dendritic cells in immunity and tolerance after allogeneic hematopoietic stem cell transplantationTransplant Immunology, 2003
- Effectiveness of Donor Natural Killer Cell Alloreactivity in Mismatched Hematopoietic TransplantsScience, 2002
- Prevention of Graft Versus Host Disease by Inactivation of Host Antigen-Presenting CellsScience, 1999