1. Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
2. Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
3. Department of Chemistry, University of California, Berkeley, California, USA
4. Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
5. Howard Hughes Medical Institute, University of California, Berkeley, California, USA