1. Department of Microbiology, State Key Laboratory of Medical Immunology, Second Military Medical University, Shanghai, People's Republic of China.
2. Department of Infectious Disease, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China.
3. Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
4. Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.