1. Section of Immunology, Wright-Fleming Institute, Imperial College, London, United Kingdom;
2. Imperial Molecular Pathology Laboratory, Imperial College Healthcare NHS Trust and Academic Health Sciences Centre, Hammersmith Hospital, London, United Kingdom;
3. Centre for Haematology, Faculty of Medicine, Imperial College, Hammersmith Hospital, London, United Kingdom;
4. Section of Virology, Wright-Fleming Institute, Imperial College, London, United Kingdom; and
5. Institute for Viral Research, Kyoto University, Kyoto, Japan