Kyushu University Academic Staff Educational and Research Activities Database
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Takahiro Nagasawa Last modified date:2023.11.27

Graduate School
Undergraduate School

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
PhD (agriculture)
Country of degree conferring institution (Overseas)
Field of Specialization
Fish Immunology
Total Priod of education and research career in the foreign country
Research Interests
  • Study of for sexual cycles of Elasmobranchii for their reproduction in aquarium
    keyword : Elasmobranchii, hormone, shark
  • Study of an activation of innate immune response by fish B cells
    keyword : Fish immunology, B cell, innnate immunity
  • Study of a regulation of inflammatory/anti-inflammatory response by phagocytic fish thrombocytes
    keyword : Fish immunology, thrombocyte, innnate immunity
Academic Activities
1. Takahiro Nagasawa, Tomonori Somamoto, and Miki Nakao, TLR-MEDIATED TYPE-I INTERFERON PRODUCTION AND THE REGULATORY MECHANISMS IN CARP THROMBOCYTES, International conference on Fish & Shellfish Immunology 2019, 2019.06.
2. Takahiro Nagasawa, Tomonori Somamoto, Miki Nakao, VIRAL LIGANDS RECOGNITION OF CARP THROMBOCYTES AS NATURAL TYPE I INTERFERON PRODUCING CELLS., 14th congress of International Society of Developmental and Comparative Immunology, 2018.06, In early stage of viral infection, viral-specific nucleic acids including single/double-stranded RNA (ss/dsRNA) are recognized by innate pattern recognition receptors, such as Toll-like receptors (TLRs), thereby type I interferon (IFN) is produced. In the present study, we report that thrombocytes in common carp (Cyprinus carpio) have potent ability to produce type I IFN in response to synthetic viral molecule mimicries. Magnetic-sorted mAb+ thrombocytes and other peripheral blood leukocytes (PBLs) were incubated with polyinosinic:polycytidylic acid (poly(I:C), an analog of dsRNA), resiquimod (R-848, an agonist of TLR7/8 which detect ssRNA), or CpG motif oligodeoxynucleotides. qPCR analysis showed that thrombocytes had produced large amount of type-I IFN compared with the PBL fraction. R-848 acutely activated the IFN production in both fractions, whereas increasing of the IFN expression by poly(I:C) were detected only in the PBL fractions. CpG DNA never induced type-I IFN expression but upregulated several inflammatory cytokines such as IL-6, suggesting that different signal pathways were activated by those ligand recognitions. After the R-848 stimulation, expression level of interferon-regulatory factor 7 (IRF7) were drastically increased in thrombocytes, suggesting that thrombocytes activated the IRF7-signal pathway to produce the IFN. Those pattern-recognition characteristics, type-I IFN producing capacity, and existence of the specialized IFN-producing pathway of carp thrombocytes are analogous to those of mammalian plasmacytoid dendritic cells, which are specialized leukocytes against viral infection, indicating that thrombocytes are important components for antiviral immunity in bony fish and can be a new target for the strategy of vaccine development..
3. Miki nakao, Sayo Iwanaga, Takahiro Nagasawa, Tomonori Somamoto, PHYLOGENETIC INFERENCE ON FUNCTIONS OF THE CLASSICAL COMPLEMENT PATHWAY IN BONY FISH, 14th congress of International Society of Developmental and Comparative Immunology, 2018.06.
4. 長澤 貴宏, 杣本智軌, 中尾 実樹, Ligand recognition specificity of carp thrombocytes as the natural type I IFN producing cells., The JSFS 85th Anniversary-Commemorative International Symposium「Fisheries Science for Future Generations, 2017.09.
5. 長澤 貴宏, 杣本 智軌, 中尾 実樹, Phagocytosis by carp thrombocyte needs activation factors secreted from other leukocytes population, 13th congress of International Society of Developmental and Comparative Immunology, 2015.06.
6. 長澤 貴宏, 中尾 実樹, 杣本 智軌, 中易 千早, Aja M. Rieger, Daniel R. Barreda, Phagocytosis and bactericidal abilities of teleost thrombocytes., 12th congress of International Society of Developmental and Comparative Immunology, 2012.06.
Membership in Academic Society
  • Japanese society for elasmobranch studies
Other Educational Activities
  • 2017.09.