1. Department of Microbiology, Peking University Health Science Center, Beijing, PR China
2. Laboratory for Immunology and Microbiology, BioMedical Education Center, Peking University Health Science Center, Beijing, PR China
3. Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Canada
4. Department of Immunology, Peking University Health Science Center, Beijing, PR China
5. Genomics Research Center, Harbin Medical University, Harbin 150081, PR China