Abstract

H. pylori infection shows an inverse relationship with allergies. Dendritic cells regulate mucosal immune responses including the induction of T regulatory cells which are fundamental in Helicobacter pylori-induced dampening of allergies. In this respect expression of high-affinity IgE receptor (Fc epsilon RI) has been associated with a regulatory dendritic cell profile. Therefore we aimed to evaluate possible mechanisms by which H. pylori infection might modify atopy in pediatric patients. Here we show that H. pylori-infected children exhibited both increased expression of Fc epsilon RI on peripheral myeloid and plasmacytoid dendritic cells and higher levels of Foxp3 and Latency Associated Peptide on T regulatory cells. Moreover, exposure to H. pylori drove increased Fc epsilon RI expression and IL 10 secretion by both pediatric H. pylori-exposed monocyte derived dendritic cells and T cells. Finally, we show a positive correlation between expression of Fc epsilon RI in circulating myeloid DCs and total Treg cells, suggesting that in children, H. pylori infection may have a modulating role in atopy, mediated by both altered surface expression of Fc epsilon RI on children's DC and an increased T regulatory cell profile. (C) 2019 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.