1. Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
2. Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA.
3. Versiti Blood Research Institute, Milwaukee, WI 53213, USA.
4. Department of Immunology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan.
5. Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75235, USA.
6. Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
7. Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
8. Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.