1. Division of Molecular and Medical Genetics, The Institute of Medical Science, Center for Gene and Cell Therapy, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
2. Administrative Section of Radiation Protection, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan
3. Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan