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Structure-guided development of fungal specific calcineurin inhibitors

真菌特异性钙调神经磷酸酶抑制剂的结构引导开发

基本信息

批准号：
10231079
负责人：
Michael Hoy
金额：
$ 3.84万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2022-06-12
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10231079
关键词：
AIDS/HIV problem Amino Acids Animal Model Animals Antifungal Agents Antifungal Therapy Antigens Aspergillus fumigatus Binding Biological Assay Body Temperature Calcineurin Calcineurin inhibitor Candida Candida albicans Candidiasis Cessation of life Chemotherapy-Oncologic Procedure Clinical Combined Modality Therapy Complex Cryptococcal Meningitis Cryptococcosis Cryptococcus Cryptococcus neoformans Cryptococcus neoformans infection Crystallization Development Docking Dose Drug Design Equilibrium Eukaryota Exhibits FK506 Flow Cytometry Fluconazole Fungal Drug Resistance Growth Histology Human Human body Immunization Immunocompromised Host Immunophilins Immunosuppression Immunosuppressive Agents In Vitro Individual Infection Interleukin-2 Lead Libraries Life Mammals Measures Minimum Inhibitory Concentration measurement Modeling Morbidity - disease rate Mus Mycoses Natural Products Organ Transplantation Oxygen PPP3CA gene Patients Pharmaceutical Preparations Phosphoric Monoester Hydrolases Production Protein phosphatase Proteins Public Health Resistance Serine Serum Specificity Structure Structure-Activity Relationship T-Cell Activation T-Lymphocyte Tacrolimus Binding Protein 1A Testing Therapeutic Threonine Toxic effect Transplant Recipients Virulence Virulence Factors Yeasts analog barrier to care base calcineurin phosphatase clinically relevant combat design drug development fungus high risk immune activation in silico in vitro activity in vivo in vivo evaluation indexing mortality mouse model new therapeutic target novel pathogen pathogenic fungus programs response small molecule synergism

项目摘要

Abstract Systemic fungal infections in immunocompromised patients have exceedingly high mortality rates. Current antifungal drugs are not sufficient to protect patients from increasing antifungal resistance and a need for new antifungals is now clearer than ever. However, similarities between targets in these eukaryotic pathogens and their human hosts have made the development of new antifungal drugs challenging. The natural product FK506 inhibits the serine-threonine specific protein phosphatase calcineurin in both fungi and humans by binding to the immunophilin FKBP12 and subsequently binding to calcineurin. In the pathogenic fungi Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus, calcineurin is a key virulence factor required for growth at human body temperature, growth in serum, and the yeast-hyphal dimorphic transition, respectively. In humans, calcineurin is required for T-cell activation and IL-2 production. In fact, FK506 is used clinically as a potent immunosuppressant. Although fungal and mammalian calcineurin and FKBP12 are highly conserved, we have recently identified key amino acid differences in the 80s loop of FKBP12 that are located at the FKBP12- FK506-calcineurin interface. A recently developed FK506 analog, APX879, is modified at a single moiety of FK506 (C22 keto oxygen) that approaches the FKBP12 80s loop. This analog exhibits significantly reduced immunosuppressive activity yet retains antifungal activity in vitro and in an animal model of cryptococcosis. Our central hypothesis is that with structure-guided rational design, FK506 analog calcineurin inhibitors can be generated with increased fungal specificity by introducing differential interactions in the 80s loop of FKBP12. In Aim 1, a defined library of FK506 analogs will be designed and synthesized based on the predicted interactions with known crystal structures for the calcineurin ternary complexes from fungi and mammals. The structure- activity relationship will then be determined by testing the spectrum of antifungal activity and the immunosuppressive activity of this library. In Aim 2 lead compounds will be tested for in vivo efficacy in murine models of cryptococcosis and in vivo immunosuppression. By defining the small molecule interactions between calcineurin, FKBP12, and FK506, compounds will be developed that shift the efficacy of calcineurin inhibition in vivo into the therapeutic window of higher antifungal activity and reduced immunosuppressive activity.

抽象的免疫功能低下患者的全身真菌感染死亡率极高。目前的抗真菌药物不足以保护患者免受抗真菌耐药性增加的影响，因此需要对于新的抗真菌药物，现在比以往任何时候都更加清晰。然而，这些真核病原体靶标之间的相似性及其人类宿主使得新抗真菌药物的开发充满挑战。天然产品 FK506 通过结合抑制真菌和人类中的丝氨酸-苏氨酸特异性蛋白磷酸酶钙调神经磷酸酶与亲免蛋白 FKBP12 结合，随后与钙调神经磷酸酶结合。病原真菌隐球菌中对于新型隐球菌、白色念珠菌和烟曲霉，钙调磷酸酶是其所需的关键毒力因子分别在人体温度下生长、在血清中生长以及酵母-菌丝二态性转变。在在人类中，钙调神经磷酸酶是 T 细胞激活和 IL-2 产生所必需的。事实上，FK506在临床上被用作强效免疫抑制剂。尽管真菌和哺乳动物钙调神经磷酸酶和 FKBP12 高度保守，但我们最近发现了 FKBP12 80s 环中的关键氨基酸差异，这些差异位于 FKBP12- FK506-钙调神经磷酸酶界面。最近开发的 FK506 类似物 APX879 在单个部分进行了修饰 FK506（C22 酮氧）接近 FKBP12 80s 环。该模拟表现出显着降低在体外和隐球菌病动物模型中，免疫抑制活性仍保留抗真菌活性。我们的中心假设是，通过结构指导的合理设计，FK506 类似钙调神经磷酸酶抑制剂可以通过在 FKBP12 的 80s 环中引入差异相互作用，产生具有增加的真菌特异性的产物。在目标 1，将根据预测的相互作用设计和合成 FK506 类似物的定义库具有来自真菌和哺乳动物的钙调磷酸酶三元复合物的已知晶体结构。结构- 然后通过测试抗真菌活性谱和该文库的免疫抑制活性。 In Aim 2 将在小鼠体内测试先导化合物的体内功效隐球菌病和体内免疫抑制模型。通过定义小分子之间的相互作用将开发钙调磷酸酶、FKBP12 和 FK506 化合物，以改变钙调磷酸酶抑制作用的功效体内进入更高抗真菌活性和降低免疫抑制活性的治疗窗口。