Ligation of TLR9 induced on human IL-10-secreting Tregs by 1alpha,25-dihydroxyvitamin D3 abrogates regulatory function
| Autor: | Christopher Corrigan, Joanne McDonald, David J. Cousins, Zahid Sattar, Zoe Urry, David F. Richards, Catherine M. Hawrylowicz, Emma Hickman, Emmanuel Xystrakis, Zarin Brown |
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| Rok vydání: | 2007 |
| Předmět: |
Adult
Male medicine.medical_treatment Stimulation chemical and pharmacologic phenomena Biology T-Lymphocytes Regulatory Dexamethasone Immune system Calcitriol medicine Humans IL-2 receptor RNA Messenger Aged Pattern recognition receptor TLR9 hemic and immune systems General Medicine Middle Aged Interleukin-10 Interleukin 10 Cytokine Oligodeoxyribonucleotides Toll-Like Receptor 9 Immunology Cancer research Receptors Calcitriol Ex vivo Research Article |
| Zdroj: | The Journal of clinical investigation. 119(2) |
| ISSN: | 0021-9738 |
| Popis: | Signaling through the TLR family of molecular pattern recognition receptors has been implicated in the induction of innate and adaptive immune responses. A role for TLR signaling in the maintenance and/or regulation of Treg function has been proposed, however its functional relevance remains unclear. Here we have shown that TLR9 is highly expressed by human Treg secreting the antiinflammatory cytokine IL-10 induced following stimulation of blood and tissue CD3+ T cells in the presence of 1alpha,25-dihydroxyvitamin D3 (1alpha25VitD3), the active form of Vitamin D, with or without the glucocorticoid dexamethasone. By contrast, TLR9 was not highly expressed by naturally occurring CD4+CD25+ Treg or by Th1 and Th2 effector cells. Induction of TLR9, but not other TLRs, was IL-10 dependent and primarily regulated by 1alpha25VitD3 in vitro. Furthermore, ingestion of calcitriol (1alpha25VitD3) by human volunteers led to an increase of both IL-10 and TLR9 expression by CD3+CD4+ T cells analyzed directly ex vivo. Stimulation of 1alpha25VitD3-induced IL-10-secreting Treg with TLR9 agonists, CpG oligonucleotides, resulted in decreased IL-10 and IFN-gamma synthesis and a concurrent loss of regulatory function, but, unexpectedly, increased IL-4 synthesis. We therefore suggest that TLR9 could be used to monitor and potentially modulate the function of 1alpha25VitD3-induced IL-10-secreting Treg in vivo, and that this has implications in cancer therapy and vaccine design. |
| Databáze: | OpenAIRE |
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