Kumamoto University - Center for AIDS Research, Kumamoto University - Center for AIDS Research, Kumamoto University - Center for AIDS Research, Kyoto University - Laboratory of Systems Virology, Kumamoto University - Center for AIDS Research, Kumamoto University - Center for AIDS Research, Kumamoto University - International Research Center for Medical Sciences, Kumamoto University - Center for AIDS Research, Kumamoto University - Department of Medical Physics, Kumamoto University - Division of Informative Clinical Sciences, St. Marianna University - Department of Rare Diseases Research, St. Marianna University - Department of Rare Diseases Research, St. Marianna University - Department of Rare Diseases Research, Kansai Medical University - Department of Microbiology, Kumamoto University - Department of Hematology, Rheumatology and Infectious Disease, Imamura General Hospital - Department of Hematology, University of Tokyo, Graduate School of Frontier Sciences, Department of Computational Biology and Medical Sciences, University of Tokyo - The Institute of Medical Science Research Hospital, University of Tokyo, Graduate School of Frontier Sciences, Department of Computational Biology and Medical Sciences, Kansai Medical University - Department of Microbiology, Imamura General Hospital - Department of Hematology, St. Marianna University - Department of Rare Diseases Research and Kumamoto University - Joint Research Center for Human Retrovirus Infection