Development of new drugs for Toxoplasma by advancing hits from the Global Health Chemical Diversity Library

弓形虫是一种多产的真核寄生虫，广泛分布于世界各地。感染 弓形虫感染可导致严重且可能致命的脑部和眼部疾病，尤其是免疫功能低下的人 个人。在世界范围内，弓形虫也是导致其他健康个体失明的主要传染性原因。 目前弓形虫的一线治疗是乙胺嘧啶和磺胺嘧啶药物的组合，但是 该方案有许多缺点。这些药物必须服用数周至数月， 经常引起毒副作用，并且无法根除慢性感染。我们需要新药 对于弓形虫来说，这种药物更安全、耐受性更好、更有效，并且给药时间更短。 为此，Alday博士和他的同事筛选了全球健康数据库中的68,689种化合物 化学多样性库（GHCDL）寻找那些抑制弓形虫生长的物质。这样做，击中了359 发现化合物可以强烈抑制这种寄生虫的生长。其中每一项的效力均已 进行了测量，并选择了 73 种高效且选择性化合物的子集进行进一步研究。所有化合物 GHCDL 中的这些物质因其类药物的理化特性而被选中，这些特性预示着良好的吸收和 口服时分布。因此，我们可以合理地推测，在 359 种化合物中 强烈抑制弓形虫生长的药物是口服时可有效对抗弓形虫病的药物 从而为开发新药提供了良好的起点。 Alday博士的研究将系统地 分三部分评价这一假设。首先，将验证所有 73 种化合物的效力。初步研究 将完成三个最有希望的结构-活性关系。其次，Alday 博士将确定 通过创建抗性突变体来了解前 10 种最有前途的化合物的作用机制 使用全基因组测序识别相关突变。最后是前10名的效果 化合物将在小鼠感染模型中进行测试。 Alday 博士是俄勒冈健康与科学大学和波特兰退伍军人管理局医学中心的医师科学家 中心。在临床上，他接受过内科和传染病 (ID) 方面的培训，轮流担任住院患者 ID 咨询服务，并设有门诊ID诊所。他的博士学位是生物化学，重点是物理 蛋白质-蛋白质和蛋白质-小分子相互作用的化学。这种不同寻常的背景给了他 从事本 CDA 申请中描述的工作的强大背景。他曾在 波特兰 VAMC 实验化疗实验室与 Michael Riscoe 博士和 Stone Doggett 博士的过去 三年，熟练掌握评估药物和药物所需的分子和生化方法 它们在原生动物寄生虫中的作用机制。本 CDA 中提出的工作将为 Alday 博士提供 他需要接受药物设计、药物机制评估和体内功效研究方面的进一步培训 成为一名独立的 VA 调查员。作为培训补助金的一部分，他组建了一支高级团队 具有分子寄生虫学和药物开发专业知识的科学家和医师科学家。总的来说， 他们指导了数十名学员走向独立。该小组将每六个月正式举行一次会议 回顾 Alday 博士的进展。此外，该小组将提供有关实验方法的意见， 在出版前审阅稿件，并提供有关职业发展的建议。阿尔戴博士将采取 药代动力学和基因组测序研究生课程，并在科学领域展示他的工作 会议。在本 CDA 结束之前，Alday 博士将确定有前景的先导化合物，准备用于 药物开发途径的进展以及未来药物开发工作的新目标。 推动这些线索的推进将构成 VA 绩效审查和 NIH R01 拨款申请的基础，这些申请将 使他成为一名独立的临床医生科学家，致力于照顾患有传染病的退伍军人 通过服务和研究来治疗疾病。

Toxoplasma gondii is a prolific eukaryotic parasite that is widely distributed throughout the world. Infection with T. gondii can cause severe and potentially fatal brain and eye disease, especially in immunocompromised individuals. Worldwide, T. gondii is also a leading infectious cause of blindness in otherwise healthy individuals. The current first-line therapy for T. gondii is a combination of the drugs pyrimethamine and sulfadiazine, but this regimen suffers from a number of shortcomings. These drugs must be taken for weeks to months, frequently cause toxic side effects, and are incapable of eradicating chronic infection. We need new medicines for T. gondii that are safer, better tolerated, more effective, and can be given for shorter durations. To this end, Dr. Alday and his colleagues have screened the 68,689 compounds in the Global Health Chemical Diversity Library (GHCDL) to find those that inhibit the growth of T. gondii. In doing so, 359 hit compounds were found that strongly inhibit the growth of this parasite. The potency of each of these has been measured and a subset of 73 highly potent and selective compounds selected for further study. All compounds in the GHCDL were chosen for their drug-like physicochemical properties that predict good absorption and distribution when taken orally. Therefore it seems reasonable to hypothesize that within the 359 compounds that strongly inhibit T. gondii growth are those that will be effective against toxoplasmosis when given orally and thus excellent starting points from which to develop new drugs. Dr. Alday's research will systematically evaluate this hypothesis in three parts. First, the potency of all 73 compounds will be verified. An initial study of the structure-activity relationships of the three most promising will be done. Secondly, Dr. Alday will determine the mechanism of action for the top 10 most promising compounds by creating resistant mutants and identifying relevant mutations using whole-genome sequencing. Finally, the effectiveness of the top 10 compounds will be tested in mouse models of infection. Dr. Alday is a physician-scientist at Oregon Health & Science University and the Portland VA Medical Center. Clinically, he is trained in internal medicine and infectious disease (ID), rotates on the inpatient ID consult service, and has an outpatient ID clinic. His PhD is in biochemistry, with a focus on the physical chemistry of protein-protein and protein-small molecule interactions. This unusual background gives him a strong background from which to pursue the work described in this CDA application. He has worked in the Portland VAMC Experimental Chemotherapy Lab with Dr. Michael Riscoe and Dr. Stone Doggett over the past three years, developing proficiency in the molecular and biochemical methods needed to evaluate drugs and their mechanism of action in protozoan parasites. The work proposed in this CDA will provide Dr. Alday with further training in drug design, evaluation of drug mechanisms, and in vivo efficacy studies he needs to become an independent VA investigator. As part of this training grant, he has assembled a team of senior scientists and physician-scientists with expertise in molecular parasitology and drug development. Collectively, they have mentored dozens of trainees towards independence. This panel will meet formally every six months to review Dr. Alday's progress. Additionally, this panel will provide input regarding experimental approaches, review manuscripts prior to publication, and give advise about career development. Dr. Alday will take graduate-level classes in pharmacokinetics and genome sequencing and present his work at scientific meetings. Prior to the end of this CDA, Dr. Alday will have identified promising lead compounds ready for advancement down the drug development pathway as well as new targets for future drug development efforts. Moving these leads forward will form the basis for VA Merit Review and NIH R01 grant applications that will establish him as an independent clinician-scientist devoted to caring for veterans afflicted by infectious diseases through service and research.