Development of Assay for High Throughput Screen of Parasite Glucose Transporter

描述(申请人提供)：寄生虫病，包括疟疾、锥虫病和利什曼病，在世界各地造成巨大的疾病负担，但迫切需要的新药的开发进展缓慢。寄生虫葡萄糖转运蛋白对疟疾、非洲锥虫和利什曼原虫的感染阶段至关重要，是药物开发的遗传学或药理学验证的靶标。在这项应用中，将开发一种高通量形式的寄生虫葡萄糖转运蛋白抑制剂的检测方法，这可能是开发新型抗寄生虫药物的先导。本试验利用墨西哥利什曼原虫葡萄糖转运蛋白缺失突变体，该突变体依赖于异源葡萄糖转运蛋白转基因在适当的培养基中的功能表达。这个空突变体将与编码恶性疟原虫六糖转运蛋白PFHT的转基因互补，并将使用AlamarBlue荧光法和SYBR Green I荧光法检测转基因寄生虫的生长情况。PFHT抑制剂将抑制转PFHT基因利什曼原虫的生长。该分析将针对高通量微滴定板格式进行优化，采用已建立的统计标准，随后将用于中等规模化学库的自动筛选，以建立其对较大化学库的最终高通量筛选的效用。从这一中等通量筛选中确定的任何抑制剂都将被进一步鉴定，以确定它们是否是PFHT的特异性抑制剂，而不是哺乳动物的葡萄糖转运蛋白，以及它们是否在培养中杀死疟疾寄生虫，但对哺乳动物细胞表现出低毒。该项目将开发一种高通量筛选方法，可用于未来的研究，以筛选来自疟疾、非洲锥虫和利什曼原虫的高亲和力、高特异性葡萄糖转运蛋白抑制剂的大型文库。长期的承诺是使鉴定先导化合物成为可能，以开发对促进全球公共卫生具有巨大潜在效用的新型抗寄生虫药物。与公共卫生的相关性。寄生虫疟疾、利什曼原虫和非洲锥虫在全球范围内造成了巨大的疾病负担，迫切需要确定新药。这项应用的目的是开发一种筛选抑制这些寄生虫摄取糖葡萄糖的化合物。由于葡萄糖是这些寄生虫的基本营养物质，这种化合物可以杀死寄生虫，并可以作为治疗它们引起的疾病的新药。

DESCRIPTION (provided by applicant): Parasitic diseases, including malaria, trypanosomiasis, and leishmaniasis, produce an enormous disease burden throughout the world, yet development of urgently needed new drugs has proceeded at a slow pace. Parasite glucose transporters are essential for the infectious stages of malaria, African trypanosomes, and Leishmania and are genetically or pharmacologically validated targets for development of drugs. In this application, an assay will be developed for high throughput format for inhibitors of parasite glucose transporters that could represent leads for development of novel anti-parasitic drugs. This assay utilizes a glucose transporter null mutant of Leishmania mexicana that is dependent for growth, in the appropriate medium, upon functional expression of a heterologous glucose transporter transgene. This null mutant will be complemented with a transgene encoding the Plasmodium falciparum hexose transporter, PfHT, and the transgenic parasites will be assayed for growth using the alamarBlue fluorescence assay and the SYBR Green I fluorescence assay. Inhibitors of PfHT will inhibit growth of the PfHT transgenic Leishmania parasites. The assay will be optimized for a high throughput microtiter plate based format employing established statistical criteria and will subsequently be employed in an automated screen of a modest size chemical library to establish its utility for eventual high throughput screening of larger chemical libraries. Any inhibitors identified from this medium throughput screen will be further characterized to determine whether they are specific inhibitors of PfHT but not mammalian glucose transporters and whether they kill malaria parasites in culture yet display low toxicity for mammalian cells. This project will develop a high throughput screening method that can be employed in future studies to screen large libraries for high affinity, high specificity inhibitors of glucose transporters from malaria, African trypanosomes, and Leishmania parasites. The long-term promise is to make possible the identification of lead compounds for development of novel anti-parasitic drugs of great potential utility for promoting global public health. Public Health Relevance. The parasites malaria, Leishmania, and the African trypanosomes cause an enormous disease burden on a global scale, and the identification of new drugs is urgently needed. The objective of this application is to develop a screen for compounds that inhibit the uptake of the sugar glucose by these parasites. Since glucose is an essential nutrient for these parasites, such compounds would kill the parasite and could act as novel drugs for treatment of the diseases they cause.