The effects of vitamin D on allergen-induced expression of interleukin-13 and interleukin-17 in cord blood CD4⁺T cells.

Cytokine production in response to allergens may influence the development of atopy-predisposing immune responses, initializing the early programming of allergy and asthma. Vitamin D intake may be protective due to its immunoregulatory properties, that may contribute to influence the expression of the atopic phenotype initiated in early life. The objective of our study was to investigate the effects of 1,25-(OH)₂D₃ on allergen-stimulated expression of asthma related cytokines in cord blood T cells. Cord blood samples were collected from the umblilical vein of 24 term deliveries during labor, CD4⁺T cells derived from cord blood mononuclear cells (CBMCs), were cultured for 72 hours with ovalbumin (OVA), β-lactoglobulin (β-LG), respectively, in presence or absence of 1,25-(OH)₂D₃ to detect the levels of interleukin-13 (IL-13) and interleukin-17 (IL-17) in culture supernatants and the mRNA expressions in CD4⁺T cells. After allergens stimulation, CD4⁺T cells showed an increase of IL-13 and IL-17 production, while cultured in the presence of 1,25-(OH)₂D₃ displayed a statistically significant down-regulation of allergen-induced expression of IL-13 and IL-17 in CD4⁺T cells. These results indicated that allergens may induce changes in CD4⁺T cell function to increase inflammatory cytokine production. 1,25-(OH)₂D₃ modulated the capacity of CD4⁺T cells in response to allergens, which might be protective for allergy.