Experimental analysis for understanding pathophysiology of rickettsial infection

2016 Fiscal Year Final Research Report

• Project/Area Number: 26461519
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Infectious disease medicine
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: ANDO Shuji 国立感染症研究所, ウイルス第一部, 室長 (30360803)
• Research Collaborator: MATSUMURA Takayuki 国立感染症研究所, 免疫部, 主任研究官 ; ANDOH Masako 鹿児島大学, 農水産獣医学領域獣医学系, 准教授
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: つつが虫病 / 動物モデル / 免疫応答 / 病態発現

Outline of Final Research Achievements

Scrub typhus caused by Orientia tsutsugamushi (Ot) ranges from lethality to non-lethality depending on Ot serotype, but relationship between pathology and serotype has been unexplained. To clarify serotype-specific pathophysiology, we infected Ot to mice. The main target cells are macrophage and vascular endothelial cells. Therefore we investigated the influence of IFNγ or nitric oxide (NO). By the serotype, increase and decrease in weight was showed as clinical symptom which was the index of infectivity in mice. The sensitivity of IFNγ or NO-knockout mice was high, especially in the IFNγ-knockout mice, weight loss was significant. In the weight loss group, a larger amount of rickettsia in spleen was detected with splenomegaly. A pathogenic difference was observed due to Ot serotype. In particular, the strain-difference was remarkable among the immunodeficient mouse, suggesting that these immune factors are important for infection control, and the mechanism is different.

Free Research Field

医歯薬学、感染症学、リケッチア、病態モデル