1. National Engineering Laboratory for AIDS Vaccine, School of Life Sciences Jilin University Changchun Jilin Province 130012 China
2. Institute of Laboratory Animal Science Chinese Academy of Medical Sciences Beijing 100021 China
3. Comparative Medicine Center Peking Union Medical College Beijing 100021 China
4. Department of Medicine Duke University School of Medicine Durham NC 27710 USA
5. Vaccine Research Center, National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda MD 20892 USA
6. Duke University Human Vaccine Institute Duke University School of Medicine Durham NC 27710 USA
7. Cancer Research Technology Program, Frederick National Laboratory for Cancer Research Leidos Biomedical Research Inc. Frederick MD 21701 USA
8. Institute of Molecular and Medical Virology, School of Medicine Jinan University Guangzhou Guangdong Province 510632 China
9. Department of Microbiology Boston University Boston MA 02215 USA
10. Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences Jilin University Changchun Jilin Province 130012 China