Functional genomic tools for in vivo study of P. vivax

描述（由申请人提供）：根除疟疾的努力将取决于能够消灭间日疟原虫的有效疗法。目前唯一获得许可的抗疟药是伯氨喹，它可以消除寄生虫的潜伏形式，即催眠虫，但它可能广泛存在寄生虫耐药性或耐受性，并且对葡萄糖-磷酸缺乏症患者有毒性。目前也没有获得许可的间日疟原虫疟疾疫苗。间日疟原虫耐药机制的研究、新药的开发或新疫苗抗原的发现都因疟原虫不易培养而变得复杂，这使得很难利用等位基因交换或瞬时转染等分子方法对疟原虫进行表型分析、描述基因特征或检验假设。由于这些困难，基因组依赖方法提供了一种最有效的方法来确定基因在做什么，它们在寄生虫中何时可能活跃，它们是如何被调节的，哪些基因可能与免疫系统相互作用，哪些基因受到宿主免疫系统或药物的选择压力。正如恶性疟原虫对基因何时转录以及它们是否被扩增或变异的描述所显示的那样，为各种药物和疫苗发现研究项目提供了基础。例如，拷贝数变异可以在基因组中检测到，活性水平受剂量补偿调节的基因可能被证明是有趣的新型药物靶点。在唾液腺孢子体中高度转录并表现出免疫选择特征的基因，如CelTos，可能编码红细胞前疫苗的新候选抗原。这是一个探索性项目，旨在验证一种假设，即已经成功用于培养恶性疟原虫的相同基因组依赖方法可以用于直接从感染患者身上获得的间日疟原虫。如果成功，这项工作将建立一个分子工具箱，供研究间日疟原虫野外分离株的研究人员使用，并提供基线转录和变异性数据，这些数据可能对那些决定候选疫苗、研究人群、复发率或耐药性传播的人有用。这项工作还将为其他研究间日疟原虫的人提供试剂和生物信息学资源。

DESCRIPTION (provided by applicant): Efforts to eradicate malaria will depend on having effective therapies that can eliminate Plasmodium vivax. At present the only licensed antimalarial that can accomplish the elimination of the latent form of the parasite, the hypnozoites, is primaquine, which has liabilities in terms of likely widespread parasite resistance or tolerance, and toxicity to individuals with glucose 6 phosphate deficiency. There is also currently no licensed vaccine for P. vivax malaria. Efforts to study the mechanisms of drug resistance in P. vivax, to develop novel drugs or to discover new vaccine antigens are complicated by the fact that the parasite cannot be easily cultured, making it difficult to phenotype parasites, characterize genes or test hypotheses using molecular methods such as allelic exchange or transient transfection. Because of these difficulties genome-dependent methods offer one of the most efficient ways to determine what genes are doing, when they may be active in the parasite, how they are regulated, which genes may be interacting with the immune system, and which are under selective pressure from the host immune system or from drugs. As has been shown in P. falciparum descriptions of when genes are transcribed, and whether or not they are amplified or variable provides a foundation for a variety of drug and vaccine discovery research projects. For example copy number variants may be detected within the genome and genes whose activity levels are regulated by dosage compensation may prove to be interesting novel drug targets. Genes which are highly transcribed in the salivary gland sporozoite and which exhibit signatures of immune selection, such as CelTos, may encode new candidate antigens for preerythrocytic vaccines. This is an exploratory project that seeks to test the hypothesis that the same genome-dependent methods that have been used successfully with cultured P. falciparum can be used on P. vivax parasites that have been obtained directly from infected patients. If successful the work will establish a molecular toolbox that can be used by researchers working on field isolates of P. vivax and provide baseline transcription and variability data that may be useful to those making decisions about vaccine candidates, studying populations, relapse rates or the spread of drug resistance. The work will also provide reagents and bioinformatic resources that can be used by others studying P. vivax.