1. Department of Pediatrics, University of Washington, Seattle, Washington.
2. Center for Global Infectious Diseases Research, Seattle Children's Research Institute, Seattle, Washington.
3. Department of Microbiology, University of Washington, Seattle, Washington.
4. Molecular Immunity Unit, MRC Laboratory of Molecular Biology, Department of Medicine, University of Cambridge, Cambridge, United Kingdom.
5. Department of Medicine, University of Washington, Seattle, Washington.