ABSTRACT
Background: Various populations of regulatory T cells play a central role in the development of peripheral tolerance to allergens. Culturing of CD4+ T cells isolated from peripheral blood of allergic patients with vitamin D induces the generation of stable IL-10 producing CD4+CD25+ Treg cells suppressing the proliferation of T helper cells obtained from the same patients. The immune regulatory role of vitamin D in allergic patients has been controversial and obviously needs a more clarifying research work
Aim of the work: to determine the percentage of induced T regulatory cells producing interleukin 10 after stimulation of T regulatory cells with cow milk allergen in the presence of vitamin D in culture. This aims to further in-vitro study the immune regulatory role of vitamin D in cow milk allergic patients
Results: there is association between decreased level of vitamin D and milk-allergy, as serum level of 25[OH] D3 was insufficient in 16 [80 %] patients [10- 29.9 ng/ml] while 4 [20%] patients were sufficient [30-100 ng/ml]. Addition of vitamin D, in culture, induces the production of CD4+ CD25hi Foxp3+ IL10+. Treg cells within peripheral blood mononuclear cells [PMNCs] isolated from allergic children who had insufficient vitamin D, but not in allergic children who had normal level of vitamin D
Conclusion: this work provides further evidence for an important role of 1,25[OH]2D3 as an immune-modulatory molecule and suggests that supplementation of vitamin-D-deficient individuals, who are reported to have reduced numbers of circulating and Foxp3+ IL10+ Treg cells, may represent an attractive therapy for enhancing endogenous populations of Treg cells in allergy