Vitamin D Regulation of Immune Function in the Gut: Why Do T Cells Have Vitamin D Receptors?

Mol Aspects Med. 2012 Feb;33(1):77-82. doi: 10.1016/j.mam.2011.10.014. Epub 2011 Nov 6.

Abstract

Low vitamin D status is associated with an increased risk of immune-mediated diseases like inflammatory bowel disease (IBD) in humans. Experimentally vitamin D status is a factor that shapes the immune response. Animals that are either vitamin D deficient or vitamin D receptor (VDR) deficient are prone to develop IBD. Conventional T cells develop normally in VDR knockout (KO) mice but over-produce IFN-γ and IL-17. Naturally occurring FoxP3+ regulatory T cells are present in normal numbers in VDR KO mice and function as well as wildtype T regs. Vitamin D and the VDR are required for the development and function of two regulatory populations of T cells that require non-classical MHC class 1 for development. The two vitamin D dependent cell types are the iNKT cells and CD4/CD8αα intraepithelial lymphocytes (IEL). Protective immune responses that depend on iNKT cells or CD8αα IEL are therefore impaired in the vitamin D or VDR deficient host and the mice are more susceptible to immune-mediated diseases in the gut.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Calcitriol / pharmacology
  • Humans
  • Inflammatory Bowel Diseases / immunology
  • Inflammatory Bowel Diseases / metabolism
  • Intestines / immunology*
  • Natural Killer T-Cells / drug effects
  • Natural Killer T-Cells / immunology
  • Receptors, Antigen, T-Cell, alpha-beta / metabolism
  • Receptors, Calcitriol / metabolism*
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Vitamin D / metabolism
  • Vitamin D / pharmacology
  • Vitamin D / physiology*

Substances

  • Receptors, Antigen, T-Cell, alpha-beta
  • Receptors, Calcitriol
  • Vitamin D
  • Calcitriol