Through the course of life, from the moment of birth till death, an organism will achieve various states of equilibrium or ‘homeostasis’ which will inevitably encounter perturbations. The processes of cell growth, differentiation, infection, mutation, evolution and adaptation work together as a coordinated ‘system’, described by mathematical models for population dynamics, to maintain a healthy state. Any disruptions to this system leads to disease including infection, allergy, cancer, and aging. I am conducting interdisciplinary research to elucidate “Quantitative Population Dynamics” through the course of life with original mathematical theory and computational simulation, which are both our CORE approach. Our mathematical model-based approach has quantitatively improved a current gold-standard approach essentially relying on the statistical analysis of “snapshot data” during dynamic interaction processes in life sciences research. Integrating current high-throughput technics including next-generation sequencer and mathematical sciences, we would like to make a paradigm shift in future life sciences research. Our developing approach could be applied to population dynamics of virus infections, immune system (e.g. differentiation process from hematopoietic stem cell or other specific immune cell) and to other aspects of cancer progression in terms of quantitative understandings for complex life phenomena including different time-scales and multi-layer data.
B.S. Osaka Prefecture University, Japan, 2005 (Mathematics and Physics)
M.S. Osaka Prefecture University, Japan, 2007 (Mathematical Biology)
Ph.D. Shizuoka University, Japan, 2009 (Mathematical Biology)
Japan Society for the Promotion of Science for Young Scientists, DC1 (2007.4-2009.3)
Japan Society for the Promotion of Science for Young Scientists, PD (2009.4-2009.9)
Japan Science and Technology Agency, PRESTO Researcher (2009.10-2013.3)
Japan Science and Technology Agency, PRESTO Researcher (2014.10- 2018.3)
INSERM, U941, Paris, France, Visiting Professor (2015.10-2016.3)
Department of Biology, Kyushu University, Associate Professor (2011.11-Current)
Institute for the Advanced Study of Human Biology (ASHBi), Kyoto University, Collaborative researcher (2020.4-Current)
NEXT-Ganken Program, Japanese Foundation for Cancer Research (JFCR), Visiting Researcher (2020.4-Current)
S. Iwanami, K. Kitagawa, H. Ohashi, Y. Asai, K. Shionoya, W. Saso, K. Nishioka, H. Inaba, S. Nakaoka, T. Wakita, O. Diekmann, S. Iwami＊†, and K. Watashi＊†. Stay or leave? : a quantitative dynamics study of how hepatitis C virus deals with this dilemma, PLoS Biol, accepted (2020).
M. Iwamoto, W. Saso, R. Sugiyama, K. Ishii, M. Ohki, S. Nagamori, R. Suzuki, H. Aizaki, A. Ryo, J-H Yun, S-Y Park, N. Ohtani, M. Muramatsu, S. Iwami, Y. Tanaka, C. Sureau, T. Wakita and K. Watashi. Epidermal growth factor receptor is a host entry cofactor triggering hepatitis B virus internalization, Proc Natl Acad Sci USA, 116:8487-8492 (2019).
K. Kitagawa, T. Kuniya, S. Nakaoka, Y. Asai, K. Watashi and S. Iwami＊ Mathematical analysis of a transformed ODE from a PDE multiscale model of hepatitis C virus infection, Bulletin of Mathematical Biology, 81:1427-1441 (2019).
E. Yamada, S. Nakaoka, L. Klein, E. Reith, S. Langer, K. Hopfensperger, S. Iwami, G. Schreiber, F. Kirchhoff, Y. Koyanagi, D. Sauter and K. Sato. Human-specific adaptations in Vpu conferring anti-tetherin activity are critical for efficient early HIV-1 replication in vivo, Cell Host & Microbe, 23:110-120 (2018).
M. Mahgoub, J. Yasunaga, S. Iwami, S. Nakaoka, Y. Koizumi, K. Shimura, and M. Matsuoka. Sporadic on/off switching of HTLV-1 Tax expression is crucial to maintain the whole population of virus-induced leukemic cells, Proc Natl Acad Sci USA, 115(6):E1269-E1278 (2018).
H. Ohashi, Y. Koizumi, K. Fukano, T. Wakita, AS. Perelson, S. Iwami＊†, and K. Watashi＊†. Reply to Padmanabhan and Dixit: Hepatitis C virus entry inhibitors for optimally boosting direct-acting antiviral-based treatments, Proc Natl Acad Sci USA, 114:E4527-E4529 (2017).
Y. Koizumi, H. Ohashi, S. Nakajima, Y. Tanaka, T. Wakita, AS. Perelson, S. Iwami＊†, and K. Watashi＊†. Quantifying antiviral activity optimizes drug combinations against hepatitis C virus infection, Proc Natl Acad Sci USA, 114:1922-1927 (2017).
K. Fujiu†, M. Shibata†, Y. Nakayama, F. Ogata, S. Matsumoto, K. Noshita, S. Iwami, S. Nakae, I. Komuro, R. Nagai, and I. Manabe. A heart-brain-kidney network controls adaptation to cardiac stress through tissue macrophage activation, Nature Medicine, 23:611-622 (2017).
A. Martyushev, S. Nakanoka, K. Sato, T. Noda†, and S. Iwami＊†. Modelling Ebola virus dynamics: Implications for therapy, Antiviral Research, 135:62-73 (2016).
S. Iwami＊†, JS Takeuchi†, S Nakaoka, F Mammano, F Clavel, H Inaba, T Kobayashi, N Misawa, K Aihara, Y Koyanagi, K Sato＊. Cell-to-cell infection by HIV contributes over half of virus infection, Elife, 4, (2015).
†Equal contribution, ＊Corresponding author(s)
Best paper award, The Japan Society for Industrial and Applied Mathematics (2010),
Young Research Award, Japan Society of Mathematical Biology (2010)