1. Institute for Genetic Medicine; Hokkaido University; Kita-ku Sapporo 060-0815 Japan
2. Department of Medical Technology; Tokyo University of Technology; 5-23-22 Nishikamata, Ohta-ku Tokyo 144-8535 Japan
3. Department of Immunology, Graduate School of Medicine; University of the Ryukyus; Uehara 207 Nishihara-cho Okinawa 903-0125 Japan
4. Department of Medicinal Chemistry; Tokyo University of Pharmacy and Life Science; 1432-1, Horinouchi Hachioji Tokyo 192-0392 Japan