PD-1-dependent mechanisms maintain peripheral tolerance of donor-reactive CD8+ T cells to transplanted tissue
| Autor: | Christian P. Larsen, Shivaprakash Gangappa, Keshawna Borom, Ivana R. Ferrer, Brent H. Koehn, Mandy L. Ford, Allan D. Kirk |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Immunology
CD40 Ligand Programmed Cell Death 1 Receptor Thymus Gland CD8-Positive T-Lymphocytes Article Mice Immune system Antigen CD28 Antigens Immunology and Allergy Cytotoxic T cell Animals Transplantation Homologous Mice Knockout CD40 biology Graft Survival CD28 Peripheral tolerance Skin Transplantation Antigens Differentiation Blockade Cell biology Up-Regulation Transplantation biology.protein Transplantation Tolerance Signal Transduction |
| Zdroj: | Journal of immunology (Baltimore, Md. : 1950). 181(8) |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Peripheral mechanisms of self-tolerance often depend on the quiescent state of the immune system. To what degree such mechanisms can be engaged in the enhancement of allograft survival is unclear. To examine the role of the PD-1 pathway in the maintenance of graft survival following blockade of costimulatory pathways, we used a single-Ag mismatch model of graft rejection where we could track the donor-specific cells as they developed endogenously and emerged from the thymus. We found that graft-specific T cells arising under physiologic developmental conditions at low frequency were actively deleted at the time of transplantation under combined CD28/CD40L blockade. However, this deletion was incomplete, and donor-specific cells that failed to undergo deletion up-regulated expression of PD-1. Furthermore, blockade of PD-1 signaling on these cells via in vivo treatment with anti-PD-1 mAb resulted in rapid expansion of donor-specific T cells and graft loss. These results suggest that the PD-1 pathway was engaged in the continued regulation of the low-frequency graft-specific immune response and thus in maintenance of graft survival. |
| Databáze: | OpenAIRE |
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