1. Department of Microbiology and Immunology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
2. Division of Hematology, Department of Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
3. Department of Pathology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
4. Department of Immune Regulation, Research Institute, National Center for Global Health and Medicine, Japan
5. Department of Pathology, Saitama Medical University, Japan