Investigation of the role of extracellular vesicles from HBV infected cells in composition of intestinal microbiota

• Project/Area Number: 18K15131
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49030:Experimental pathology-related
• Research Institution: Tokai University
• Principal Investigator: KAKIZAKI Masatoshi 東海大学, 医学部, 助教 (00778954)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2019: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2018: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: B型肝炎ウイルス / 細胞外小胞 / ハイドロダイナミックインジェクション / PD-L1 / 腸管免疫 / HBV / 肝臓 / 腸管 / 腸内細菌叢 / 骨髄

Outline of Final Research Achievements

In this study, we used a mouse model of HBV infection to elucidate the effects of extracellular vesicles (EVs) derived from HBV-infected cells on HBV-related pathologies and their role in intestinal immunity. The results showed that EVs secreted from cells with HBV infection strongly suppressed the immune response, which inhibited the eradication of HBV-replicating cells in the HBV mouse model of infection. It was suggested that up-regulation of PD-L1 expression in dendritic cells in liver-draining lymph nodes may be important for the suppression of this eradication. Furthermore, the addition of infected cell-derived EVs to the culture supernatant of bone marrow cells increased the proportion of CD11c+ CD11b+ CD103+ cells, an immunomodulatory DC population in the gut. These results suggest that bone marrow cells that take up EVs derived from HBV-infected cells may affect intestinal immunity.

Academic Significance and Societal Importance of the Research Achievements

これまで、HBV感染細胞から放出される細胞外小胞(EVs)の機能を解析した研究はなされてきたが、全てIn vitroでの研究であった。本研究は、HBV感染マウスモデルを使って初めてIn vivoでHBV感染細胞由来EVsの機能を明らかにしたものである。この機能は、HBV感染細胞由来EVsは免疫応答を強く抑制し、HBV複製細胞の排除を抑制するものである。さらに、HBV感染細胞由来EVsは腸管免疫にも影響与えている可能性を示唆する結果も得られた。これらの結果は、B型肝炎関連病態の理解を深めるとともに、新規治療の開発への足がかりとなることも期待できる。

Research Products

• [Journal Article] PD-L1/L2 protein levels rapidly increase on monocytes via trogocytosis from tumor cells in classical Hodgkin lymphoma (2020)
  • Author(s): Kawashima M, Carreras J, Higuchi H, Kotaki R, Hoshina T, Okuyama K, Suzuki N, Kakizaki M, Miyatake Y, Ando K, Nakayama M, Umezu S, Horie R, Higuchi Y, Katagiri K, Goyama S, Kitamura T, Chamoto K, Yano S,Nakamura N, and A Kotani
  • Journal Title: Leukemia Volume: - Issue: 9 Pages: 2405-2417
  • DOI: 10.1038/s41375-020-0737-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] PD-L1 is induced on hepatocyte surface via CKLF-like MARVEL transmembrane domain-containing protein 6 upregulation by the anti-HBV drug Entecavir (2020)
  • Author(s): Yamamoto Yuichiro、Kakizaki Masatoshi、Shimizu Takayuki、Carreras Joaquim、Chiba Tetsuhiro、Chamoto Kenji、Kagawa Tatehiro、Aoki Taku、Nakamura Naoya、Ando Kiyoshi、Kotani Ai
  • Journal Title: International Immunology Volume: - Issue: 8 Pages: 519-531
  • DOI: 10.1093/intimm/dxaa018
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The immunological function of extracellular vesicles in hepatitis B virus-infected hepatocytes (2018)
  • Author(s): Kakizaki Masatoshi、Yamamoto Yuichiro、Yabuta Suemi、Kurosaki Natsumi、Kagawa Tatehiro、Kotani Ai
  • Journal Title: PLOS ONE Volume: 13 Issue: 12 Pages: e0205886-e0205886
  • DOI: 10.1371/journal.pone.0205886
  • Peer Reviewed / Open Access
• [Presentation] Multi organ association mediated by extracellular vesicles secreted from HBV positive hepatocyte (2019)
  • Author(s): Ai Kotani, Masatoshi Kakizaki, Yuichiro Yamamoto, Motoyuki Otsuka, and Tatehiro Kagawa
  • Organizer: International society for extracellular vesicles 2019
  • Int'l Joint Research
• [Presentation] Extracellular vesicles secreted from HBV-infected cells inhibit the eradication of HBV-infected cells in the HBV-infection mouse model. (2019)
  • Author(s): Masatoshi Kakizaki, Yuichiro Yamamoto, Ai Kotani
  • Organizer: 第48回日本免疫学会学術集会