Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Today our bodies are exposed to a wide variety of type of small particles such as live pathogens, environmental PM2.5 and engineered nanoparticles. When these particles enter the body, many of them are recognized by the innate immune cells such as macrophages and provoke inflammation. The mechanism for the immune responses to microbial particles has been extensively studied so far. We have recently investigated the mechanism by which phagocytes such as macrophages and dendritic cells recognize apoptotic cells and microbes (1, 2). Further, we have also revealed the immune regulation by intercellular transfer of immune cell membrane vesicles (3, 4).

Besides organic particles, the immune system responds to inorganic particles as described above. For example, silica particles strongly activate macrophages (5), and the inhalation of silica induces chronic inflammation leading to silicosis, which is one of the most prevalent occupational diseases worldwide. The nanotechnology has enabled us to generate various ultrafine nanoparticles that have unique physical properties. These nanoparticles have been applied not only for optics and electron but also for biomedicine. However, biological responses to inorganic nanoparticles remain largely unknown. To understand the molecular mechanisms for the immune responses to nanoparticles, we here perform the interdisciplinary research between cell biology, immunology, and physics. Our research will hopefully open the way not only to new intervention strategies to prevent or predict the toxicity of inorganic particles but also to the next-generation nanomedicines.

References

1. Nakayama M, et al, Blood, 113, 3821-3830, 2009
2. Nakayama M, et al, J Immunol, 189, 5903-5911, 2012
3. Nakayama M, et al, PNAS, 108, 18360-18365, 2011
4. Nakamura K, Nakayama M, et al, PNAS, 110, 9421-9426, 2013
5. Kusaka T, Nakyama M, et al, PLoS ONE, e92634, 2014