Authors and Affiliations

Authors and Affiliations

Reiko Sugawara,^1,2,8,* Eun-Jung Lee,^3,4,* Min Seong Jang,^3,4,10 Eun-Ji Jeun,^3,4 Chun-Pyo Hong,^3,4 Jung-Hwan Kim,^3,4 Areum Park,⁴ Chang Ho Yun,³ Sung-Wook Hong,³ You-Me Kim,^4,5 Ju-Young Seoh,⁶ YunJae Jung,⁷ Charles D. Surh,^3,4 Masayuki Miyasaka,^2,8,9 Bo-Gie Yang,^3,** and Myoung Ho Jang^3,8,**

 

¹Department of Respiratory Medicine, Allergy, and Rheumatic Diseases, Graduate School of Medicine, Osaka University, 565-0871 Suita, Japan 

²Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, 565-0871 Suita, Japan 

³Academy of Immunology and Microbiology, Institute for Basic Science, 790-784 Pohang, Republic of Korea 

⁴Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 790-784 Pohang, Republic of Korea 

⁵Department of Life Sciences, Pohang University of Science and Technology, 790-784 Pohang, Republic of Korea 

⁶Department of Microbiology, Graduate School of Medicine, Ewha Womans University, 158-710 Seoul, Republic of Korea 

⁷Department of Microbiology, School of Medicine, Gachon University, 21936 Incheon, Republic of Korea 

⁸WPI Immunology Frontier Research Center, Osaka University, 565-0871 Suita, Japan 

⁹MediCity Research Laboratory, University of Turku, 20520 Turku, Finland 

¹⁰Viral Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, 34141 Daejeon, Republic of Korea 

 

Author Notes
^* R. Sugawara and E.-J. Lee contributed equally to this paper.
^** M.H. Jang and B.-G. Yang contributed equally to this paper.

Correspondence : Myoung Ho Jang or Bo-Gie Yang

Eosinophils play proinflammatory roles in helminth infections and allergic diseases. Under steady-state conditions, eosinophils are abundantly found in the small intestinal lamina propria, but their physiological function is largely unexplored. In this study, we found that small intestinal eosinophils down-regulate Th17 cells. Th17 cells in the small intestine were markedly increased in the ΔdblGATA-1 mice lacking eosinophils, and an inverse correlation was observed between the number of eosinophils and that of Th17 cells in the small intestine of wild-type mice. In addition, small intestinal eosinophils suppressed the in vitro differentiation of Th17 cells, as well as IL-17 production by small intestinal CD4⁺ T cells. Unlike other small intestinal immune cells or circulating eosinophils, we found that small intestinal eosinophils have a unique ability to constitutively secrete high levels of IL-1 receptor antagonist (IL-1Ra), a natural inhibitor of IL-1β. Moreover, small intestinal eosinophils isolated from IL-1Ra-deficient mice failed to suppress Th17 cells. Collectively, our results demonstrate that small intestinal eosinophils play a pivotal role in the maintenance of intestinal homeostasis by regulating Th17 cells via production of IL-1Ra.