1. DNAVEC Research, Inc., Tsukuba, Ibaraki 305-0856, Japan; Shionogi & Co., Ltd., Discovery Research Laboratories, Fukushima, Osaka, 553-0002, Japan
2. DNAVEC Research, Inc., Tsukuba, Ibaraki 305-0856, Japan; Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
3. Research Center for Acquired Immunodeficiency Syndrome, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
4. Tsukuba Primate Center for Medical Science, National Institute for Infectious Diseases, Tsukuba, Ibaraki 305-0843, Japan
5. DNAVEC Research, Inc., Tsukuba, Ibaraki 305-0856, Japan