1. Department of Immunology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Higashinari-ku, Osaka, Japan.
2. Institute for Biological Resources and Functions, Age Dimension Research Center, National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Japan.
3. Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.