The 94th Annual Meeting of Japanese Society for Bacteriology

Presentation information

On-demand Presentation

6 Virulence Factors and Biophylaxis

[ODP6B] b. Toxins, Effectors, and Bioactive Substances

[ODP-125] Analysis of IL-33-inducing activity of Citrobacter koseri in dendritic cells

○Hideo Kataoka, Taiki Mori, Takeshi Into (Dept. Oral Microbiology, Division of Oral Infection and Health Sciences, Asahi Univ. Sch. Dentistry)

Purpose: Food allergy is thought as an intestinal immune dysfunction elicited by dysbiotic gut microbiota. We previously reported that Citrobacter species, which have propagated in the feces of mice with food allergy, were found to worsen allergic symptoms by inducing IL-33 production in intestinal epithelial cells. On the other hand, dendritic cells can play important roles in the intestinal mucosal immune system. In this study, we therefore analyzed whether Citrobacter koseri induces IL-33 production in dendritic cells.
Materials & Methods: Bacterial LPS derived C. koseriJCM1658 was extracted by means of the phenol-water method. Expression of Il33 in a DC2.4 mouse dendritic cell line was detected by real time PCR and IL-33 production was quantified by ELISA. ATP concentration in the culture supernatant was quantified with BacTiter-Glo Microbial Cell Viability Assay (Promega).
Results & Discussion: IL-33 production was induced by live bacteria of C. koseri, but not by extracted LPS in DC2.4. LPS reduced IL-33 production induced by live bacteria and DC2.4 proliferation. Live bacteria of C. koseri increased ATP concentration in the culture supernatant but LPS inhibited this increment. From the above, C. koseri increases IL-33 production through ATP production but LPS restricted the production by inhibiting dendritic cell proliferation.