Experimental Plasmodium falciparum crosses using human-liver chimeric mice

 描述(申请人提供)：疟疾由疟原虫引起，每年有近100万人死于疟疾。由于抗药性寄生虫菌株、抗药性蚊子媒介的传播，以及在实施和维持有效控制方案方面的固有困难，这种疾病是可怕的。今天，对青蒿素联合疗法产生的耐药性对疟疾控制构成了重大威胁。青蒿素联合疗法是治疗简单疟疾的标准药物疗法。了解抗疟疾耐药性的遗传基础是关键，并将为开发新的干预措施提供信息。疟疾寄生虫菌株之间的实验杂交是确定表型遗传决定因素的最有效方法，重要的是，过去曾成功地用于确定恶性疟原虫耐药性的遗传基础。然而，到目前为止，由于与这一过程相关的巨大实际和经济障碍，只进行了三次恶性疟原虫试验性杂交，而这一过程无法在人类身上进行，因此使用了切除脾的黑猩猩。对来自精心设计的杂交组合的重组后代进行遗传分析，可以非常有效地确定决定表型性状的遗传位点，并且在群体遗传学研究中具有重要的优势。鉴于美国国立卫生研究院最近决定停止在生物医学研究中使用黑猩猩，实验杂交将不再可用，这实际上使未来的未来遗传学研究变得不可能。然而，我们最近发现，含有人肝细胞的小鼠(FRG KO huHep小鼠)输注人红细胞可以支持恶性疟原虫的子孢子感染、完成肝期发育以及过渡到无性血期复制。我们假设FRG KO huHep小鼠可以成功地用于常规和强大的恶性疟原虫实验杂交，从而取代以前必不可少的黑猩猩宿主。我们有数据表明，我们能够利用这个模型进行实验性的遗传杂交，杂交产生的独立重组后代将用于重组以及基因类型和相关表型的分析。此外，我们还与一个最新的青蒿素抗性田间分离物进行了实验杂交，使我们能够研究青蒿素抗性的基础。与寄生虫基因操作、高通量表型鉴定和系统遗传学等快速改进的技术相结合，一个强大的疟疾遗传研究模型现已触手可及。

 DESCRIPTION (provided by applicant): Plasmodium parasites cause the disease malaria, which kills close to one million people per year. The disease is formidable, due to the spread of drug-resistant parasite strains, insecticide-resistant mosquito vectors and the inherent difficultis in the implementation and maintenance of effective control programs. Today, emerging resistance to artemisinin combination therapy, which is the standard drug treatment for uncomplicated malaria, poses a significant threat to malaria control. Understanding the genetic basis of antimalarial drug resistance is key and will inform development of new interventions. Experimental crosses between malaria parasite strains are the most powerful way to determine the genetic determinants of phenotypes, and importantly, have been successfully used to determine the genetic basis of P. falciparum drug resistance in the past. To date however, only three P. falciparum experimental crosses have been carried out due to the enormous practical and financial hurdles associated with the process, which cannot be performed in humans, and thus used splenectomized chimpanzees. The genetic analysis of recombinant progeny from a well-conceived cross can be extremely powerful for pinpointing the genetic loci determining a phenotypic trait and has important advantages over population genetic studies. Given the recent decision by the NIH to cease the use of chimpanzees in biomedical research, experimental crosses will no longer be available, effectively rendering future forward genetic studies impossible. However, we have recently shown that a mouse harboring human hepatocytes (the FRG KO huHep mouse) infused with human red blood cells can support P. falciparum sporozoite infection, complete liver stage development as well as the transition to asexual blood stage replication. We hypothesize that the FRG KO huHep mouse can be utilized successfully for routine and robust P. falciparum experimental crosses, thereby replacing the previously essential chimpanzee host. We have data to show that we are able to perform experimental genetic crosses utilizing this model and the crosses generated independent recombinant progeny that we will use for analysis of recombination as well as genotypes and associated phenotypes. Furthermore, we have also carried out an experimental cross with a recent field isolate resistant to artemisinin, allowing us to study the basis of artemisinin resistance. Combined with rapidly improving technologies, such as parasite genetic manipulation, high throughput phenotyping and Systems Genetics, a powerful model for malaria genetic research is now within reach.