1. Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan.
2. Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan.
3. Department of Biochemistry, Keio University School of Medicine, Tokyo 160-8582, Japan.
4. Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Tokyo 102-0075, Japan.
5. RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan.