stimulates dendritic cells to induce IL-33 expression via abundant ATP production.

Food allergies (FAs) occur due to intestinal immune dysfunction elicited by dysbiotic conditions. It was previously determined by us that species propagate in the faeces of mice with FAs and worsen allergic symptoms by inducing the allergenic cytokine IL-33. Dendritic cells can play important roles in regulation of FA responses. species propagating in intestines of mice worsen allergic symptoms by stimulating dendritic cells to induce IL-33 expression. The aim of the present study was to analyse whether stimulates dendritic cells to induce IL-33 expression. IL-33 expression was evaluated in a DC2.4 mouse dendritic cell line stimulated by live or heat-inactivated JCM1658, ATP, LPS extracted from JCM1658 or other enterobacteria by real-time PCR. The ATP concentration and number of live bacteria in the culture supernatant were measured simultaneously. Live JCM1658 induced higher levels of IL-33 expression than other enterobacteria tested, but such a response was not elicited by heat-inactivated JCM1658. LPS extracted from JCM1658 did not induce IL-33 expression and suppressed live JCM1658-induced IL-33 expression via the activation of Toll-like receptor 4 signalling. Furthermore, ATP produced by JCM1658 stimulated dendritic cells to induce IL-33 expression by stimulating the P2X receptor, and LPS attenuated extracellular ATP-induced IL-33 expression. JCM1658 was observed to proliferate more vigorously and produce more ATP than other enterobacteria. acts as an allergenic bacterium through ATP production, stimulating dendritic cells to induce IL-33 expression, while LPS released from inactivated JCM1658 attenuates this allergenicity.