1. AIDS Vaccine Research Institute, Department of Pathobiological Sciences, University of Wisconsin-Madison, 585 Science Dr. Madison, WI 53711, USA
2. Department of Genetics, University of Wisconsin-Madison, 425 Henry Mall Madison , WI 53706, US
3. Influenza Research Institute, Department of Pathobiological Sciences, University of Wisconsin-Madison, 575 Science Dr. Madison, WI 53711, USA
4. Division of Virology, Institute of Medical Science, University of Tokyo, 4 Chome-6-1 Shirokanedai Minato City, Tokyo 108-0071, Japan
5. Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka Suita City , Osaka 565-0871, Japan
6. Center for Infectious Disease Education and Research (CiDER), Osaka University, 2-8 Yamadaoka Suita City , Osaka 565-0871, Japan
7. The Research Center for Global Viral Diseases, National Center for Global Health and Medicine Research Institute, 1 Chome-21-1 Toyama Shinjuku City , Tokyo 162-8655, Japan
8. Department of Pathobiology, University of Pennsylvania, 3800 Spruce Street Philadelphia , PA 19104, USA
9. Department of Biology, Emory University, 1510 Clifton Road NE Atlanta , GA 30322, USA