Viral Vector Vaccine Development for Bovine Piroplasmosis in Japan

(1)建立了东方蛇形芽孢杆菌体外实验培养体系，该体系可用于研究寄生虫对红细胞的渗透或释放、寄生虫的增殖和抑制药物的开发。(2)对隶属于东方血吸虫血吸虫螺旋体目的罗氏巴贝斯虫、微氏巴贝斯虫、gibsoni巴贝斯虫、equi巴贝斯虫和caballi巴贝斯虫的多个基因进行了克隆和鉴定，为东方血吸虫血吸虫感染病毒载体疫苗的研制提供了基础和关键信息。(3)开展了媒介蜱长角血蜱（haemophyyslis longicornis）几种生物活性分子的基因克隆和分子特性研究，部分阐明了媒介蜱对伊氏杆菌和巴贝斯虫的内部防御机制。证实了媒介蜱的肌钙蛋白I、过氧化物还氧蛋白和几丁质酶在寄生虫传播中起重要作用，是开发传播阻断疫苗的候选分子。(4)利用转基因敲除小鼠，研究了清道夫受体和干扰素-γ在免疫应答和获得宿主对长角天牛反复侵染的抗性中的作用。该结果为研制有效的抗蜱疫苗提供了重要信息。

(1) in vitro experimental culture system of Theileria orientalis sergenti has been established and it has been demonstrated that this system might be very useful for studies of parasite penetration of or liberation from red blood cells, proliferation of parasites, and the development of inhibitory medicines.(2) The cloning and characterization of several genes of Babesia rodhaini, B. microti, B. gibsoni, B. equi and B. caballi, which belong to the same order, Piroplasmidora, to T. orientalis sergenti, were carried out to get the fundamental and crucial information for the viral vector vaccine development of T. orientalis sergenti infections.(3) The gene cloning and molecular characterization of several bioactive molecules of vector ticks, Haemaphyslis longicornis, were carried out and the internal defense mechanisms of vector ticks against Theileria and Babesia parasites were partially clarified. It was verified that Troponin I, peroxiredoxin, and chitinase of vector ticks play important roles for parasite transmission and a candidate molecule for the transmission-blocking vaccine development.(4) The roles of scavenger receptors and interferon-γ on immune response and acquisition of host resistance against repeated infestations with H. longicornis were investigated using transgenic knockout mice. The results provide the important information for the development of effective anti-tick vaccine.