RT Journal Article
SR Electronic
T1 Co-culture of naïve CD4+ T cells and vitamin D modulate – Th17 cells in young asthmatic children
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 3232
VO 44
IS Suppl 58
A1 Besma Hamdi
A1 Wajih Kaabachi
A1 Berraies Anissa
A1 Ammar Jamel
A1 Kamel Hamzaoui
A1 Agnes Hamzaoui
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/3232.abstract
AB 1,25-Dihydroxyvitamin D3 (Vit D) deficiency has been associated with childhood asthma inflammatory pathways, however data are still lacking about the effect of vitamin D supplementation on immune regulation in asthmatic children. In this study, we investigated Vit D inhibitory effect on the immune response in young asthmatic patients and the possible mechanisms involved.Peripheral blood CD4+ T cells from 10 asthmatic patients with hypovitaminosis D and 10 healthy controls were cultured under Th17 polarizing conditions in the presence or absence of Vit D, and IL-17cytokines production was determined by ELISA and flow cytometry. mRNA expression of several factors related to Th17 cell function were determined by real-time PCR. The effect of Vit D-treated dendritic cells (DCs) on CD4+ T cell response was determined by ELISA and flow cytometry.Stimulation of naive CD4+ T cells under Th17 polarizing conditions showed a higher Th17 cell differentiation in asthmatic patients than healthy controls. The addition of Vit D significantly inhibited Th17 cell differentiation both in patients[P < 0.0004] and in normal controls [P = 0.0001] in dose dependent way. Vit D was able to inhibit the gene expression of RORC, IL-17, IL-23R, and CCR6 differenciation. Vit D-treated DCs significantly inhibited IL-17 level [291.0 ± 83.59pg/ml v.s. 452.0 ± 116.0 pg/ml; P = 0.0022] and decreased the percentage of CD4+IL-17+ [4.35% ± 1.12% v.s. 5.91% ± 1.17%;P = 0.0072] in young asthmatics.The findings suggest that the inhibitory effect of VitD on the Th17 response was mediated via both T cells and DCs. DCs pathway is involved in the direct inhibition of VitD on Th17 cell differentiation in young asthmatics.