Molecular basis of the adaptation of Plasmodium knowlesi to human erythrocytes using mutator parasite lines

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K15125
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Parasitology (including sanitary zoology)
• Research Institution: Nagasaki University
• Principal Investigator: KANEKO Osamu 長崎大学, 熱帯医学研究所, 教授 (50325370)
• Research Collaborator: KATAKAI Yuko (社)予防衛生協会, 研究支援開発部, 部長 ; YAHATA Kazuhide 長崎大学, 熱帯医学研究所, 助教 ; LUCKY Amuza Byarhanga 長崎大学, 医歯薬学総合研究科 ; ASARE Kwame Kumi 長崎大学, 医歯薬学総合研究科 ; TAKEDA Mika 長崎大学, 熱帯医学研究所, 特任研究員
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 原虫 / マラリア / 人獣共通感染症 / 遺伝子導入 / 進化

Outline of Final Research Achievements

The infectivity to and pathogenicity of Plasmodium knowlesi, a causative agent of monkey malaria, in human is varied depending on the endemic areas, but the molecular basis to determine this difference is not clearly understood. Because in vitro culture-adapted P. knowlesi does not grow efficiently with human erythrocytes, I hypothesized that this growth phenotype may explain the observation in the endemic areas. To identify P. knowlesi factor(s) that enable parasites to grow with human erythrocytes, we generated a panel of mutator parasite lines in which mutation rate would be artificially increased. Continuous in vitro culture with rhesus monkey erythrocytes, in which amount of human erythrocytes are gradually increased, however, did not yield P. knowlesi line with increased growth speed during supported period. Furthermore, we found that Hackeri line that was isolated from a mosquitoe and maintained in monkey was also able to invade human erythrocytes even the frequency was low.

Free Research Field

基礎医学・寄生虫学（含衛生動物学）