1. Department of Molecular and Medical Pharmacology, University of California—Los Angeles, Los Angeles, California, USA
2. Department of Microbiology, Immunology, and Molecular Genetics, University of California—Los Angeles, Los Angeles, California, USA
3. Department of Cellular and Molecular Pharmacology, University of California—San Francisco, San Francisco, California, USA
4. Pathology and Laboratory Medicine, University of California—Los Angeles, Los Angeles, California, USA
5. CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, People's Republic of China