Functional genomic tools for in vivo study of P. vivax

描述(申请人提供)：根除疟疾的努力将取决于是否有有效的治疗方法来消灭间日疟原虫。目前，唯一获得许可的能够消除寄生虫潜在形式催眠虫的抗疟药是伯喹，它可能会产生广泛的寄生虫耐药性或耐受性，并对葡萄糖6-磷酸缺乏症患者产生毒性。目前也没有获得许可的间日疟疫苗。间日疟原虫不容易培养，这使得研究间日疟原虫耐药机制、开发新药或发现新的疫苗抗原的努力变得复杂，这使得使用等位基因交换或瞬时转基因等分子方法来对寄生虫进行表型、基因特征描述或验证假说变得困难。由于这些困难，基因组依赖的方法提供了一种最有效的方法来确定基因在做什么，它们在寄生虫中什么时候可能活跃，它们是如何调节的，哪些基因可能与免疫系统相互作用，以及哪些基因受到来自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，这为各种药物和疫苗发现研究项目提供了基础。例如，可以在基因组中检测到拷贝数变异，其活性水平受剂量补偿调节的基因可能被证明是有趣的新药物靶点。在唾液腺子孢子中高度转录并表现出免疫选择特征的基因，如CelTOS，可能编码新的前红细胞疫苗候选抗原。这是一个探索性项目，旨在检验一种假设，即已成功用于培养恶性疟原虫的相同基因组依赖方法，也可以用于直接从感染患者那里获得的间日疟原虫。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做出关于候选疫苗、研究人群、复发率或耐药性传播的决策有用。这项工作还将提供试剂和生物信息资源，供其他研究间日疟原虫的人使用。

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.