1. State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Grazing Animal Diseases of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu, China
2. Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
3. Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, USA