Department of Hematology, Imamura General Hospital, Japan;
Dr. Utsunomiya, MD, PhD, serves as Honorable Director of Imamura General Hospital, Director of Clinical Research Center, and Director of the HTLV-1 Research Center (2018–present). Since the discovery of ATL in 1977, he has been engaged in clinical research on ATL as a hematologist. His work includes analyzing ATL clinical manifestations, conducting treatment development research through the Japan Clinical Oncology Group-Lymphoma Study Group, and developing hematopoietic stem cell transplantation using non-myeloablative conditioning regimens for elderly patients with aggressive ATL. In new drug development, he participated in clinical trials for mogamulizumab, lenalidomide, tucidinostat, and valemetostat, contributing to their approval in Japan. He also participates in a prospective cohort study on HTLV-1, the causative virus of ATL (Joint Study on Predisposing Factors of ATL Development), and in a research group investigating the reality of horizontal transmission and prevention strategies. He is now a member of multiple research projects on HTLV-1/ATL supported by the Japan Agency for Medical Research and Development (AMED) (Project Numbers: 25fk0108671h0003, 25ck0106789h0003).

Division of Genomics and Transcriptomics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Japan;
Yorifumi Satou, MD, PhD is a virus researcher at Kumamoto University whose work centers on HTLV-1 immunovirology and the pathogenesis of adult T-cell leukemia/lymphoma (ATL). He integrates molecular virology with human immunology to explain how persistent retroviral infection reshapes T-cell function and drives disease. A defining thread of his research is the characterization of the HTLV-1 antisense gene HBZ and its immunobiological consequences. Foundational studies in PNAS (2006) and PLoS Pathogens (2011) delineated HBZ expression and function, establishing it as a driver of infected-cell persistence and a rational target for immune and therapeutic interventions. Satou has also advanced the concept of intragenic proviral regulation, demonstrating that HTLV-1 modulates its transcriptional landscape through internal regulatory elements rather than relying solely on the canonical long terminal repeat (LTR). Milestone papers in PNAS (2016), Nature Communications (2022), and Nature Microbiology (2025) mapped these intragenic programs and clarified how they govern latency, reactivation, and tissue-specific expression—insights that now underpin strategies to measure and modulate proviral activity in vivo. Bridging mechanism to disease, his team showed that ATL cells are profoundly activated T cells, not merely transformed quiescent lymphocytes (JCI, 2021). This reframed ATL as a malignancy entwined with chronic T-cell activation, with implications for immunometabolic targeting, exhaustion pathways, and rational immunotherapy design. Satou mentors trainees and collaborates across Japan and internationally, applying single-cell readouts, high-parameter cytometry, and spatial profiling to connect proviral control with host immunity. By uniting HBZ biology, intragenic regulation, and T-cell activation states, his program charts actionable routes to improved diagnostics and treatments for HTLV-1–associated diseases.

Department of Infectious Disease, Faculty of Medicine, Imperial College London;
Aileen trained as an immunologist at Trinity College Dublin. After completing her PhD, Aileen joined Charles Bangham’s lab in Imperial College to investigate the T cell-mediated immune response to HTLV. During her time there, she also developed methods to identify clonally expanded ATL cells in peripheral blood, and joined Graham Taylor’s laboratory in 2017 to develop her method into a diagnostic test to detect and quantify ATL clones. Using this test, she showed that ATL-like clones circulate in the peripheral blood in the premalignant, asymptomatic stage of ATL. In 2022 Aileen was appointed as a lecturer at Imperial College, and established a research group that focuses on understanding the natural history of ATL development.

Department of Infectious Disease, Faculty of Medicine, Imperial College London;
Dr Rosadas is a research fellow at the department of infectious disease, Imperial College London. She is keen to support improving access to diagnostics and to help advancing the public health response to neglected infections, especially focusing on HTLV. She has been working extensively with the Brazilian Ministry of Health, the Pan American Health Organization and the World Health Organization to support evidence-based public health response. She is passionate about science communication and community engagement and has co-founded a social media platform, HTLV Channel, to increase awareness about this virus, share research findings with the community, empower civil society and promote inter-sectoral collaboration.