Abstract
One central mechanism, by which vitamin D regulates human immune responses, is the direct modulation of dendritic cells (DCs). However, the effect of vitamin D on several key DC functions, such as the secretion of central inflammatory cytokines, remains controversial. Moreover, whether vitamin D treatment of DCs regulates their ability to promote differentiation of IL-17-/IL-22-producing T cell subsets, such as Th17 and Th22 cell, is not known. Here, we report that vitamin D treatment during differentiation of monocytes into DCs markedly enhanced their ability to secrete TNF-α, IL-6, IL-1β and IL-23. Cytokines secreted by vitamin D-treated DC were significantly more potent in driving differentiation of IL-22-producing T cells, but not IL-17-producing T cells, as compared to secreted cytokines of not-vitamin D-treated DCs. Finally, we found that the differentiation of IL-22-producing T cells mediated by supernatants of vitamin D-treated DCs was dependent on TNF-α IL-6 and IL-23. In summary, our study suggests a novel role of vitamin D in regulating DC-mediated immune responses in humans.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Differentiation*
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Cells, Cultured
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Coculture Techniques
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Dendritic Cells / cytology
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Dendritic Cells / metabolism*
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Gene Expression Regulation*
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Humans
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Inflammation
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Interleukin-1beta / metabolism
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Interleukin-22
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Interleukin-23 / metabolism
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Interleukin-6
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Interleukins / metabolism*
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Lymphocyte Activation / immunology
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Monocytes / cytology
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T-Lymphocytes / cytology*
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T-Lymphocytes / metabolism
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Th17 Cells / cytology
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Tumor Necrosis Factor-alpha / metabolism
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Vitamin D / pharmacology*
Substances
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IL1B protein, human
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IL6 protein, human
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Interleukin-1beta
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Interleukin-23
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Interleukin-6
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Interleukins
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Tumor Necrosis Factor-alpha
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Vitamin D
Grants and funding
This work was funded by the Ministry of Innovation, Science, Research and Technology of the German State of North Rhine-Westphalia (Grant No. NRW Rückkehrerprogramm,
http://www.wissenschaft.nrw.de/), the Center for Molecular Medicine (Grant No. GB4,
http://www.zmmk.uni-koeln.de/), and the Deutsche Forschungsgemeinschaft (Grant No. SFB829 - B13;
http://www.dfg.de/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.