1. Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
2. Center for Cancer and Metabolism, SRI International, Menlo Park, California, USA
3. Department of Basic Science, New York University College of Dentistry, New York, New York, USA
4. Section of Infectious Diseases, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts, USA
5. Laboratory of Immunoregulation, NIAID, National Institutes of Health, Bethesda, Maryland, USA
6. Department of Medical Microbiology, Laboratory of Experimental Virology, Center for Infection and Immunity, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands