OBJECTIVETo study the effect of 1,25-(OH)2D3 on lipopolysaccharide (LPS)-induced expression of interleukin-13 (IL-13) and interleukin-17 (IL-17) in cord blood CD4(+)T cells, providing theoretical basis for clinical reasonable application of vitamin D and prevention of asthma and allergic diseases.

METHODSMononuclear cells (MNCs) were isolated from umbilical cord blood (50 mL) of 12 normal eutocia term newborns by gravity centrifugation. CD4(+)T cells were isolated using magnetic beads, which was cultured with following three kinds of stimulus for 72 hours: natural state (blank group), LPS (10 μg/mL)stimulation alone and LPS(10 μg/mL)+1,25-(OH)2D3 (10(-8) mmol/L)stimulation. Levels of IL-13 and IL-17 in the culture supernatant and mRNA expressions in cord blood CD4(+)T cells were detected using ELISA and real Time-PCR respectively.

RESULTSCompared with the blank group, levels of IL-13 and IL-17 in the culture supernatant and mRNA expression of IL-13 and IL-17 in the cord blood CD4(+)T cells increased in the LPS stimulation alone group (P<0.01). When co-stimulation of 1,25-(OH)2D3 with LPS, levels of IL-13 and IL-17 in the culture supernatant and mRNA expression of IL-13 and IL-17 in the cord blood CD4(+)T cells decreased compared with LPS-stimulated alone group (P<0.05), but remained higher than the blank group (P<0.01).

CONCLUSIONSLPS can promote expression of IL-13 and IL-17 in cord blood CD4(+)T cells. 1,25-(OH)2D3 inhibits the expression of IL-13 and IL-17, suggesting that vitamin D intake may provide protective effects in the development of atopy-predisposing immune responses in early life.