T lymphocytes and vitamins

CD8+ T-Cell Deficiency, Epstein-Barr Virus Infection, Vitamin D Deficiency, and Steps to Autoimmunity: A Unifying Hypothesis

“…Exposure to natural sunlight or treatment in a solarium increases the proportion of CD8+ T cells and decreases the CD4/CD8 T cell ratio in peripheral blood [ 75 – 77 ]. Exactly how sunlight increases the number of CD8+ T cells is unclear, but the effect is probably mediated at least in part by vitamin D because (1) among cells of the immune system, activated CD8+ T cells express the highest concentrations of the vitamin D receptor [ 78 ]; (2) vitamin D increases the mitogen-induced proliferation of CD8+ T cells and decreases the CD4/CD8 ratio in bovine peripheral blood mononuclear cells in vitro [ 79 ]; (3) vitamin D administration increases the CD8+ T cell count [ 80 ]; (4) vitamin D deficiency is associated with a decreased proportion of CD8+ T cells and increased CD4/CD8 ratio [ 81 ]. Here it is proposed that deprivation of sunlight and vitamin D aggravates the genetically determined CD8+ T cell deficiency and impaired control of EBV infection and thereby contributes to the high prevalence of autoimmune diseases such as MS, type 1 diabetes, and RA at high latitudes [ 82 – 84 ] ( Figure 3 ) and that the protective effect of vitamin D against autoimmune diseases [ 85 – 87 ] is mediated at least in part by an increase in the number of CD8+ T cells available to control EBV.…”

The Essential Role of Epstein-Barr Virus in the Pathogenesis of Multiple Sclerosis

“…Exposure to natural sunlight or treatment in a solarium increases the proportion of CD8+ T cells and decreases the CD4/CD8 T cell ratio in peripheral blood (Hersey and others 1983a; Hersey and others 1983b; Falkenbach and Sedlmeyer 1997). Exactly how sunlight increases the number of CD8+ T cells is unclear, but the effect is probably mediated at least in part by vitamin D because (1) among cells of the immune system, activated CD8+ T cells express the highest concentrations of the vitamin D receptor (Veldman and others 2000); (2) vitamin D increases the mitogen-induced proliferation of CD8+ T cells and decreases the CD4/CD8 ratio in bovine PBMC in vitro (Nonnecke and others 1993); (3) vitamin D administration increases the CD8+ T cell count (Žofková and Kancheva 1997); and (4) vitamin D deficiency is associated with a decreased proportion of CD8+ T cells and increased CD4/CD8 ratio (Çakmak and others 1999). Thus, it is proposed that the increasing incidence of MS with increasing latitude is due to aggravation of genetic CD8+ T cell deficiency, with resulting poorer control of EBV infection.…”

Hypothesis: bipolar disorder is an Epstein–Barr virus‐driven chronic autoimmune disease – implications for immunotherapy

“…Treatment in a solarium or exposure to natural sunlight increases the proportion of circulating CD8 + T cells and decreases the CD4/CD8 T‐cell ratio 72‐74 . This effect of light is likely to be mediated at least partly by vitamin D for the following reasons: (1) within the immune system, the cells expressing the greatest concentration of the vitamin D receptor are activated CD8 + T cells 75 ; (2) vitamin D augments the mitogen‐induced proliferation of CD8 + T cells and lowers the CD4/CD8 ratio in vitro 76 ; (3) administration of vitamin D increases the CD8 + T‐cell count 77 ; and (4) in vitamin D deficiency, the proportion of CD8 + T cells in the blood decreases and the CD4/CD8 ratio increases 78 . Interestingly, T cells also have an intrinsic sensitivity to blue light, which increases T‐cell motility through a H 2 O 2 signalling pathway 79 …”