Human CD4+ T Cells Express TLR5 and Its Ligand Flagellin Enhances the Suppressive Capacity and Expression of FOXP3 in CD4+CD25+ T Regulatory Cells
| Autor: | Natasha K. Crellin, Rosa Garcia, Omeed Hadisfar, Megan K. Levings, Sarah E. Allan, Theodore S. Steiner |
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| Rok vydání: | 2005 |
| Předmět: |
CD4-Positive T-Lymphocytes
CD3 Complex T cell Immunology chemical and pharmacologic phenomena Biology T-Lymphocytes Regulatory Interleukin 21 medicine Humans Immunology and Allergy Cytotoxic T cell IL-2 receptor Antigen-presenting cell Antibodies Monoclonal CD28 FOXP3 Forkhead Transcription Factors Receptors Interleukin-2 hemic and immune systems Up-Regulation Cell biology Toll-Like Receptor 5 medicine.anatomical_structure TLR5 Interleukin-2 Flagellin |
| Zdroj: | The Journal of Immunology. 175:8051-8059 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Germline encoded pattern recognition receptors, such as TLRs, provide a critical link between the innate and adaptive immune systems. There is also evidence to suggest that pathogen-associated molecular patterns may have the capacity to modulate immune responses via direct effects on CD4+ T cells. Given the key role of both CD4+CD25+ T regulatory (Treg) cells and the TLR5 ligand flagellin in regulating mucosal immune responses, we investigated whether TLR5 may directly influence T cell function. We found that both human CD4+CD25+ Treg and CD4+CD25− T cells express TLR5 at levels comparable to those on monocytes and dendritic cells. Costimulation of effector T cells with anti-CD3 and flagellin resulted in enhanced proliferation and production of IL-2, at levels equivalent to those achieved by costimulation with CD28. In contrast, costimulation with flagellin did not break the hyporesponsiveness of CD4+CD25+ Treg cells, but rather, potently increased their suppressive capacity and enhanced expression of FOXP3. These observations suggest that, in addition to their APC-mediated indirect effects, TLR ligands have the capacity to directly regulate T cell responses and modulate the suppressive activity of Treg cells. |
| Databáze: | OpenAIRE |
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