1 Division of Systems Virology, Department of Microbiology and Immunology, University of Tokyo, Tokyo 113-8654, Japan.
2 Division of Systems Virology, Department of Microbiology and Immunology, University of Tokyo, Tokyo 113-8654, Japan; Institute of Medical Science, and Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo 113-8654, Japan.
3 Division of Systems Virology, Department of Microbiology and Immunology, University of Tokyo, Tokyo 113-8654, Japan; Faculty of Liberal Arts, Sophia University, Tokyo, Japan.
4 Division of Systems Virology, Department of Microbiology and Immunology, University of Tokyo, Tokyo 113-8654, Japan; International Research Center for Infectious Diseases, University of Tokyo, Tokyo 113-8654, Japan.
5 Division of Systems Virology, Department of Microbiology and Immunology, University of Tokyo, Tokyo 113-8654, Japan; International Research Center for Infectious Diseases, University of Tokyo, Tokyo 113-8654, Japan; International Vaccine Design Center, University of Tokyo, Tokyo 113-8654, Japan; Institute of Medical Science, and Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo 113-8654, Japan; Graduate School of Medicine, University of Tokyo, Tokyo 113-8654, Japan; Collaboration Unit for Infection, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan; Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, UK. Electronic address: keisato@g.ecc.u-tokyo.ac.jp.