Abstract
The molecular mechanisms governing orderly shutdown and retraction of CD4+ type 1 helper T (TH1) cell responses remain poorly understood. Here we show that complement triggers contraction of TH1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated the transition from pro-inflammatory interferon-γ+ TH1 cells to suppressive interleukin-10+ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4+ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VitD receptor shaped the transcriptional response to VitD. Accordingly, VitD did not induce interleukin-10 expression in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4+ T cells of patients with COVID-19 were TH1-skewed and showed de-repression of genes downregulated by VitD, from either lack of substrate (VitD deficiency) and/or abnormal regulation of this system.
© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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25-Hydroxyvitamin D3 1-alpha-Hydroxylase / metabolism
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Basic-Leucine Zipper Transcription Factors / metabolism
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Bronchoalveolar Lavage Fluid / cytology
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COVID-19 / immunology
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COVID-19 / pathology
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Complement C3a / immunology
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Complement C3b / immunology
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Humans
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Interferon-gamma / immunology*
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Interleukin-10 / immunology*
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JNK Mitogen-Activated Protein Kinases / metabolism
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Lymphocyte Activation / immunology
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Receptors, Calcitriol / metabolism
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Respiratory Distress Syndrome / immunology
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Respiratory Distress Syndrome / pathology
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Respiratory Distress Syndrome / virology
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SARS-CoV-2 / immunology*
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STAT3 Transcription Factor / metabolism
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Signal Transduction / immunology
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Th1 Cells / immunology*
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Transcription, Genetic / genetics
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Vitamin D / metabolism*
Substances
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BACH2 protein, human
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Basic-Leucine Zipper Transcription Factors
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IFNG protein, human
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IL10 protein, human
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Receptors, Calcitriol
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STAT3 Transcription Factor
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STAT3 protein, human
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VDR protein, human
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Interleukin-10
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Vitamin D
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Complement C3a
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Complement C3b
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Interferon-gamma
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25-Hydroxyvitamin D3 1-alpha-Hydroxylase
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CYP27B1 protein, human
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JNK Mitogen-Activated Protein Kinases