1. Department of Biochemistry and Biophysics, Texas A&M University , College Station, TX 77843, USA
2. Center for Global Infectious Disease Research, Seattle Children's Research Institute , Seattle , WA 98109, USA
3. Departments of Pediatrics and Global Health, University of Washington School of Medicine , Seattle , WA , USA
4. Institute of Immunology and Infection Research, University of Edinburgh , Edinburgh EH9 3FL, UK
5. Department of Microbiology, Harvard Medical School , Boston , MA 02115, USA