1. Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
2. Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
3. Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
4. Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
5. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
6. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA