J Immunol. 2015. pii: 1500344. [Epub ahead of print]
The immunoregulatory functions of vitamin D have been well documented in various immunological disorders, including multiple sclerosis, arthritis, and asthma. IL-10 is considered a chief effector molecule that promotes the vitamin D-induced immunosuppressive states of T cells and accessory cells. In this article, we demonstrate that the active form of vitamin D, 1,25-dihydroxyvitamin D3 (calcitriol), has a profound inhibitory effect on the development of human Th9, a CD4 T cell subset that is highly associated with asthma, in an IL-10-independent manner. Our data show that calcitriol represses the expression of BATF, a transcription factor essential for Th9, via suppressing the expression of aryl hydrocarbon receptor, without an increase in IL-10. The data show a novel link between vitamin D and two key transcription factors involved in T cell differentiation..
CD4(+) T-helper cells regulate immunity and inflammation through the acquisition of potential to secrete specific cytokines. The acquisition of cytokine-secreting potential, in a process termed T-helper cell differentiation, is a response to multiple environmental signals including the cytokine milieu. The most recently defined subset of T-helper cells are termed Th9 and are identified by the potent production of interleukin-9 (IL-9). Th9 cells might be involved in pathogen immunity and immune-mediated disease. (review click here). In this study they report that vitamin D suppresses BAFT (Basic leucine zipper transcription factor, ATF-like) and reduces the Aryl_hydrocarbon_receptor. Is this how vitaminD affects multiple sclerosis?