1. From the Department of Immunology, Wright-Fleming Institute, Imperial College London, St Mary's Campus, London, United Kingdom; the Department of Genito-Urinary Medicine and Communicable Diseases, Wright-Fleming Institute, Imperial College London, St Mary's Campus, London, United Kingdom; and the Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukus, Nishihara, Okinawa, Japan.