International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya; Cell Biology and Immunology Group, Wageningen University, The Netherlands.
Cell Biology and Immunology Group, Wageningen University, The Netherlands.
Int J Parasitol. 2018 Mar;48(3-4):265-273. doi: 10.1016/j.ijpara.2017.09.007. Epub 2017 Dec 16.
East Coast fever is a lymphoproliferative disease caused by the tick-borne protozoan parasite Theileria parva. The sporozoite stage of this parasite, harboured and released from the salivary glands of the tick Rhipicephalus appendiculatus during feeding, invades and establishes infection in bovine lymphocytes. Blocking this initial stage of invasion presents a promising vaccine strategy for control of East Coast fever and can in part be achieved by targeting the major sporozoite surface protein p67. To support research on the biology of T. parva and the identification of additional candidate vaccine antigens, we report on the sporozoite proteome as defined by LC-MS/MS analysis. In total, 4780 proteins were identified in an enriched preparation of sporozoites. Of these, 2007 were identified as T. parva proteins, representing close to 50% of the total predicted parasite proteome. The remaining 2773 proteins were derived from the tick vector. The identified sporozoite proteins include a set of known T. parva antigens targeted by antibodies and cytotoxic T cells from cattle that are immune to East Coast fever. We also identified proteins predicted to be orthologs of Plasmodium falciparum sporozoite surface molecules and invasion organelle proteins, and proteins that may contribute to the phenomenon of bovine lymphocyte transformation. Overall, these data establish a protein expression profile of T. parva sporozoites as an important starting point for further study of a parasitic species which has considerable agricultural impact.
东非热是一种由蜱传原生动物寄生虫泰勒虫引起的淋巴增生性疾病。该寄生虫的裂殖体阶段,在蜱虫 Rhipicephalus appendiculatus 进食时从唾液腺中携带和释放出来,入侵并在牛淋巴细胞中建立感染。阻断这一初始入侵阶段为控制东非热提供了一种有前途的疫苗策略,部分可以通过靶向主要裂殖体表面蛋白 p67 来实现。为了支持对 T. parva 生物学和其他候选疫苗抗原的研究,我们报告了通过 LC-MS/MS 分析定义的裂殖体蛋白质组。在富含裂殖体的制剂中,共鉴定出 4780 种蛋白质。其中,2007 种被鉴定为 T. parva 蛋白,接近寄生虫总预测蛋白质组的 50%。其余 2773 种蛋白质来自蜱虫载体。鉴定出的裂殖体蛋白包括一组已知的 T. parva 抗原,这些抗原被对东非热具有免疫力的牛的抗体和细胞毒性 T 细胞靶向。我们还鉴定了预测为恶性疟原虫裂殖体表面分子和入侵细胞器蛋白的同源蛋白,以及可能有助于牛淋巴细胞转化现象的蛋白。总的来说,这些数据建立了 T. parva 裂殖体的蛋白质表达谱,这是进一步研究具有相当农业影响的寄生虫物种的重要起点。