Vitamin D effects on B cell function in autoimmunity

Abstract

Vitamin D seems to be implicated in the pathophysiology of autoimmune disorders as a natural immune modulator. Beneficial effects of vitamin D have been associated with different cells of the immune system; however, thus far, B cells seem to be somewhat neglected. In this paper, we describe the possible direct effects of vitamin D on B cells, with a focus on antibody production and the more recently identified regulatory B (Breg ) cells. B cells upregulate the vitamin D receptor (VDR) upon activation. Furthermore, due to regulated expression of the metabolizing enzymes CYP27B1 and CYP24A1, B cells have the potential to control the local availability of active vitamin D. B cells, therefore, may participate in vitamin D-mediated immune homeostasis, including plasma cell generation. Whether or not other B cell subsets, such as Breg cells, are equally responsive to vitamin D remains to be established.

Anti-Inflammatory Effects of Vitamin D on Human Immune Cells in the Context of Bacterial Infection

“…Indeed, sustained high levels of TNF-α, IL-6 and IFN-γ are associated with increased disease severity during pneumococcal pneumonia [33]. The ability of 1,25(OH) 2 D 3 to control inflammation through IL-10 is intriguing, and is consistent with its reported anti-inflammatory effects [34,35,36,37,38] and ability to induce functional regulatory T cells (Treg) [39,40]. Our data suggest this may be due to an increased CD14 expression although our small sample size limit the significance of this finding.…”

Association between vitamin D receptor polymorphisms and systemic lupus erythematosus in an Indian cohort

“…It does not purport to a cause–effect relationship but provides a reason for critical studies. B lymphocytes in lupus play a critical role in SLE and low vitamin D levels have been shown to enhance B cell proliferation, differentiation and production of autoantibodies …”

Vitamin D3 in cancer prevention and therapy: the nutritional issue

“…The active form of vitamin D 3 , that is, 1α,25(OH) 2 vitD 3 or calcitriol, may interact with B and T cells, as lymphocytes express VDR [23,24], where it acts by modulating regulatory T cells activity [25] or participating in naïve T cell maturation [26]. The role of VDR in the immune system is still an argument of debate but evidence suggests that calcitriol may be considered as an immune regulator [27].…”