1. Department of Microbiology, University of Iowa, Iowa City, Iowa, USA
2. Department of Immunology, University of Iowa, Iowa City, Iowa, USA
3. Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
4. Department of Internal Medicine, University Hospital Regensburg, Regensburg, Germany
5. Department of Pathology, University of Iowa, Iowa City, Iowa, USA
6. Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
7. Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA