Molecular Phylogenetics, Diagnostics and Control of Apicomplexan Parasites

我的研究计划的长期目标是在历史、生物(寄主-寄生虫)和分子水平上探索和了解尖端寄生虫门的寄生虫与它们的宿主之间的相互作用。这些寄生虫会引起重要的动物和人类疾病，如疟疾、弓形虫病、隐孢子虫病和球虫病。我建议通过从事三个主要领域的研究来加深我们对这些关系的理解：*1)使用具有形态和形态特征的多基因组分子标记来研究apicomexan系统发育和宿主-寄生虫的共同进化：我们将通过从apicomexan寄生虫感染家养和基本上被忽视的野生动物*宿主产生*序列数据(核18S rDNA、质体rDNA/聚合酶B和mt细胞色素C氧化酶I，COI)来确定apicplexan寄生虫在*人类、家养动物和野生动物(潜在的人畜共栖动物)中的生物多样性。我们新开发的聚合酶链式反应引物对将产生基于COI的物种特异性DNA条形码，用于识别球虫*(艾美尔球虫)*，包括肠道球虫(例如艾美耳球虫)*和组织(例如弓形虫)*球虫。我们将修改我们的DNA条形码引物，用于多重NGS*分析，以识别和计数生物样本(如粪便或组织样本)中的混合球虫；该方法将允许快速原生寄生虫*生物多样性和物种发现；*2)*从生物多样性的尖端复合体寄生虫*生成完整的线粒体(MT)基因组，以探索mt基因组的结构进化，并*生成推断*这些世界性寄生虫的进化史所需的序列数据。*3)探索家禽球虫的免疫控制。我们将在国内和国际上确定感染国内火鸡的艾美耳球虫的自然流行率，以确定针对火鸡球虫病的多价球虫病活疫苗所需的物种数量。我们将改进和进一步开发一种重组*多价疫苗技术，将两个寄生虫抗原表位和一个*宿主衍生的免疫调节表位(HMGB1)结合起来。*目前这种多价疫苗构建的枯草杆菌表达载体将被转化为一种严格基于多肽的形式(即*化学合成的)，并在通过各种方式*输送时在体内进行生物活性测试。成功*使用不可行的疫苗结构(全球首例)接种艾美耳球虫疫苗将解决疫苗生产、运输和保质期问题，并避免在商业家禽中*使用球虫病活疫苗对健康的影响。**

The*long term goal of my research program is to explore and understand the interactions between*parasites of the phylum Apicomplexa and their hosts at the historical,*organismal (host-parasite) and molecular levels. These parasites cause*important animal and human diseases such as malaria, toxoplasmosis,*cryptosporidiosis and coccidiosis. I propose to further our understanding of*these relationships by pursuing three main areas of study:***1) Investigate apicomplexan phylogeny and host-parasite coevolution*using multi genome molecular markers with morphological and morphometric*characters: We will determine the biodiversity of apicomplexan parasites in*humans, domesticated animals and wildlife (potential zoonotics) by generating*sequence data (nuclear 18S rDNA, plastid rDNA/polymerase B, and mt cytochrome c oxidase subunit I, COI) from*apicomplexan parasites that infect both domestic and, largely ignored, wildlife*hosts. Our newly developed PCR primer pairs will generate species-specific*COI-based DNA barcodes that will be used to identify specifically coccidia*(Eimeriorina) including enteric (e.g. Eimeria)*and tissue (e.g. Toxoplasma)*coccidia. We will modify our DNA barcode primers for use in a multiplexed NGS*assay to both identify and enumerate mixed coccidia in biological samples such*as fecal or tissue samples; this method will permit rapid protistan parasite*biodiversity and species discovery;***2)*Generate complete mitochondrial (mt) genomes from biologically diverse*apicomplexan parasites to explore the structural evolution of mt genomes and*generate sequence data necessary for inferring the evolutionary history of*these cosmopolitan parasites.***3) Explore immunological control of coccidia of domestic poultry. We*will determine*the natural prevalence of Eimeria that infect domestic turkeys*nationally and internationally to determine the number of species required in a*multivalent live coccidiosis vaccine against turkey coccidiosis. We will refine and further develop a recombinant*multivalent vaccine technology that combines two parasite antigenic epitopes with a*host-derived immune modulating epitope (HMGB1). *The current Bacillus subtilis expression vector for this multivalent*vaccine construct will be converted into a strictly peptide based (i.e.*chemically synthesized) form and tested for biological activity in vivo when*delivered by various means. Successful*vaccination against Eimeria species using a non-viable vaccine construct (a*global first) would address vaccine production, transportation and shelf life*issues as well as avoid health implications of using live coccidiosis vaccines*in commercial poultry.**