1. Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
2. Program in Biochemistry, Tufts University Graduate School of Biomedical Sciences, Boston, Massachusetts, USA
3. Program in Molecular Microbiology, Tufts University Graduate School of Biomedical Sciences, Boston, Massachusetts, USA
4. Program in Immunology, Tufts University Graduate School of Biomedical Sciences, Boston, Massachusetts, USA
5. Faculty of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain
6. Institute for Molecular Virology and Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, Wisconsin, USA