Rational design of CNS-permeable cathepsin L inhibitors for treatment of chronic toxoplasmosis

中枢神经系统渗透性组织蛋白酶 L 抑制剂治疗慢性弓形虫病的合理设计

基本信息

批准号：
9813831
负责人：
Vernon Bruce Carruthers
金额：
$ 45.97万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-12-01 至 2021-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9813831
关键词：
ABCB1 gene Ablation Address American Attenuated Biochemistry Biological Assay Blindness Blood - brain barrier anatomy Brain Brain Diseases Cathepsin L Cathepsins Cell Respiration Cells Cellular Assay Cessation of life Chemicals Chronic Crystallization Cyst Cytoplasm Dipeptides Dose Drug Kinetics Encephalitis Enzymes Genetic Goals Half-Life Heart Diseases Human Immune system In Vitro Individual Infection Intraperitoneal Injections Lead Life Liver Microsomes Lysosomes Maximum Tolerated Dose Measures Membrane Modeling Mus Myocarditis Neuropharmacology Nitriles P-Glycoprotein Parasites Parasitology Pathogenesis Penetrance Peptide Hydrolases Peripheral Permeability Pharmaceutical Chemistry Pharmaceutical Preparations Phase Plants Posterior Uveitis Property Proteins Recombinants Reporting Risk Roentgen Rays Role Structure System Therapeutic Tissues Toxoplasma gondii Toxoplasmosis Treatment Protocols Vacuole Virulence Visual impairment Work acute infection analog base carboxypeptidase C chronic infection combat design drug development foodborne high risk improved in vitro Model inhibitor/antagonist innovation mouse model novel physical property pre-clinical preclinical development relating to nervous system small molecule inhibitor stem tool unpublished works

项目摘要

PROJECT SUMMARY The complete absence of treatment options for chronic Toxoplasma gondii (Tg) infection renders ~2 billion people at risk for reactivated toxoplasmosis. Congenitally infected individuals or those with weakened immune systems are particularly vulnerable to reactivated toxoplasmosis manifested as fatal encephalitis, myocarditis or loss of vision. As the leading cause of infectious posterior uveitis and second leading cause of foodborne deaths in the USA, reactivated toxoplasmosis could be substantially reduced in high-risk individuals by eliminating Tg tissue cysts. We used new genetic tools to identify an essential role for a cathepsin protease L (CPL) activity during chronic Tg infection, creating an exciting opportunity to exploit a new target for combatting reactivated toxoplasmosis. To begin addressing this key unmet need, we identified an initial lead dipeptide nitrile CPL inhibitor based on its potential for CNS penetrance and conducted primary SAR studies against Tg and human cathepsin L, demonstrating that we could achieve over 100-fold improvement in selectivity for the Tg enzyme in under 20 analogs. In the R21 phase we will use structure-based design to further optimize potency and selectivity along with improving stability and permeability in in vitro models, delivering one or more potent, selective, stable, and cell-permeable leads. In the R33 phase we will evaluate and further refine PK and CNS penetrance in mice before measuring maximum tolerated dose and efficacy in an established murine treatment model for chronic Tg infection. Both phases will feature first-of-their-kind assays for cyst viability developed for the studies. Upon successful completion, this project will yield one or more Tg CPL inhibitors effective for reducing or eliminating tissue cysts, thereby advancing a potential new solution for chronic Tg infection. 1

项目概要慢性弓形虫 (Tg) 感染完全缺乏治疗方案，导致~2 十亿人面临弓形虫病重新激活的风险。先天性感染者或体质较弱的人免疫系统特别容易受到重新激活的弓形虫病的影响，表现为致命性脑炎，心肌炎或视力丧失。作为感染性后葡萄膜炎的主要原因和第二大原因美国食源性死亡，高风险地区弓形虫病再激活可大幅减少通过消除 Tg 组织囊肿来消除个体。我们使用新的遗传工具来确定基因的重要作用慢性 Tg 感染期间的组织蛋白酶 L (CPL) 活性，创造了一个令人兴奋的机会来利用对抗重新激活的弓形虫病的新目标。为了开始解决这一关键的未满足的需求，我们基于其中枢神经系统渗透潜力，确定了一种初始的先导二肽腈 CPL 抑制剂，针对 Tg 和人组织蛋白酶 L 进行了初步 SAR 研究，表明我们可以实现不到 20 种类似物对 Tg 酶的选择性提高了 100 倍以上。在R21阶段我们将使用基于结构的设计进一步优化效力和选择性，同时提高稳定性和体外模型的渗透性，提供一种或多种有效的、选择性的、稳定的和细胞渗透性的先导化合物。在在 R33 阶段，我们将在测量之前评估并进一步完善小鼠的 PK 和 CNS 外显率已建立的慢性 Tg 感染小鼠治疗模型中的最大耐受剂量和疗效。这两个阶段都将采用为研究开发的囊肿活力的首个检测方法。成功后完成后，该项目将产生一种或多种 Tg CPL 抑制剂，可有效减少或消除组织囊肿，从而为慢性 Tg 感染提供了一种潜在的新解决方案。 1