Analysis of Chinese Toxoplasma phylogeny and virulence

• Project/Area Number: 15H05275
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Parasitology (including sanitary zoology)
• Research Institution: Osaka University
• Principal Investigator: Yamamoto Masahiro 大阪大学, 微生物病研究所, 教授 (00444521)
• Research Collaborator: Sasai Miwa
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥16,120,000 (Direct Cost: ¥12,400,000、Indirect Cost: ¥3,720,000); Fiscal Year 2017: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2016: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2015: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
• Keywords: トキソプラズマ / 中国 / 病原性 / 免疫抑制 / アミノ酸多型 / 遺伝子多型 / トキソプラズマ原虫 / 遺伝子多様性 / 病原性因子

Outline of Final Research Achievements

Toxoplasma gondii is an pathogen causing lethal toxoplasmosis in immunocompromised individuals those suffering from AIDS and being treated by chemotherapy. In addition, this pathogen causes congentical diseases when pregnant women are firstly infected. It is postulated that nearly one-third of world populatin are oppupotunistically infected with T. gondii. Therefore, number of T. gondii-infected Japanese people might be also high. However, how Asian T. gondii including Japanese ones acts remains unclear. Therefore, we have analyzed virulence and whole genome information about Chinese T. gondii in collaboration with Chinese parasitologists.

Academic Significance and Societal Importance of the Research Achievements

トキソプラズマは免疫不全のヒトで致死的な病気を引き起こす病原体である。世界人口の３分の１が感染していると言われているが、アジアにおける実態はよくわかっていない。そこで中国の寄生虫学者とともに、中国においてトキソプラズマを分離し、その病原性や病原性因子群の遺伝子多型について検討を行った。その結果、複数の中国分離株が得られ、系統によって病原性が異なることが分かり、さらに病原性が強い方では原虫の増殖やマウス個体レベルでのサイトカインストームが起きることが分かった。

Research Products

• [Int'l Joint Research] 中山大学/寧波大学/安徽医科大学(中国)
• [Journal Article] Inducible Nitric Oxide Synthase Is a Key Host Factor for Toxoplasma GRA15-Dependent Disruption of the Gamma Interferon-Induced Antiparasitic Human Response (2018)
  • Author(s): Bando Hironori、Lee Youngae、Sakaguchi Naoya、Pradipta Ariel、Ma Ji Su、Tanaka Shun、Cai Yihong、Liu Jianfa、Shen Jilong、Nishikawa Yoshifumi、Sasai Miwa、Yamamoto Masahiro
  • Journal Title: mBio Volume: 9 Issue: 5 Pages: 5-5
  • DOI: 10.1128/mbio.01738-18
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Toxoplasma Effector TgIST Targets Host IDO1 to Antagonize the IFN-γ-Induced Anti-parasitic Response in Human Cells (2018)
  • Author(s): Bando Hironori、Sakaguchi Naoya、Lee Youngae、Pradipta Ariel、Ma Ji Su、Tanaka Shun、Lai De-Hua、Liu Jianfa、Lun Zhao-Rong、Nishikawa Yoshifumi、Sasai Miwa、Yamamoto Masahiro
  • Journal Title: Frontiers in Immunology Volume: 9 Pages: 2073-2073
  • DOI: 10.3389/fimmu.2018.02073
  • Peer Reviewed / Open Access / Int'l Joint Research