1. Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
2. Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
3. Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri, USA
4. Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
5. Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
6. The Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, Missouri, USA