1. Department of Medicinal Chemistry, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), Chiyoda-ku, Tokyo 101-0062, Japan
2. Department of Refractory Viral Infections, National Center for Global Health and Medicine Research Institute, Shinjuku-ku, Tokyo 162-8655, Japan
3. Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
4. Department of Clinical Sciences, Kumamoto University Hospital, Chuo-ku, Kumamoto 860-8556, Japan