1. Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
2. Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan.
3. Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan.
4. Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan.