1. Division of Virology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0431, Japan
2. Division of Cellular and Molecular Engineering, Department of Life Technology and Science, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8560, Japan
3. Department of Food Science, Jumonji University, 2-1-28 Sugasawa, Niiza, Saitama 352-8510, Japan