1. Division of Human Retroviruses, Center for Chronic Viral Diseases, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan
2. Pharmacology Research Laboratories II, Pharmaceutical Research Division, Takeda Chemical Industries, Osaka 532-8686, Japan
3. New Generation Research Laboratory, Pharmaceutical Research Division, Takeda Chemical Industries, Osaka 532-8686, Japan