Novel Context-Activated Protide Anti-Infectives

新型环境激活蛋白肽抗感染药

• 批准号: 7429814
• 负责人: Michael R Yeaman
• 金额: $ 22.77万
• 依托单位: NOVADIGM THERAPEUTICS, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7429814
• 关键词: Anti-Infective Agents; Antibiotic Resistance; Biological Assay; Blood; Blood Circulation; C-terminal; Cells; Class; Consensus; Data; Defensins; Development; Disease; Drug resistance; Endopeptidases; Engineering; Erythrocytes; Evolution; Explosion; Failure; Foundations; Genes; Genetic Recombination; Goals; Guanosine Monophosphate; Health; Host Defense; Human; In Vitro; Incidence; Infection; Invasive; Lead; Libraries; Life; Methods; Modeling; Molecular; Multi-Drug Resistance; Mus; N-terminal; Natural Immunity; Nature; Organism; Outcome; Peptide Hydrolases; Peptides; Phase; Phase I Clinical Trials; Plasma; Prevention; Pseudomonas aeruginosa; Screening procedure; Serum; Signal Transduction; Small Business Technology Transfer Research; Staphylococcus aureus; Structure; Technology; Testing; Therapeutic; Therapeutic Agents; Therapeutic Index; Tissues; Toxic effect; Vascular Endothelial Cell; Virulent; Whole Blood; antimicrobial; antimicrobial peptide; base; chemokine; combinatorial; cytotoxic; cytotoxicity; design; glutamyl endopeptidase; human PPBP protein; in vivo; innovation; methicillin resistant Staphylococcus aureus; microbicide; novel; novel strategies; pathogen; polypeptide; pre-clinical; prevent; prototype; response; scaffold

DESCRIPTION (provided by applicant): Antibiotic-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa are among the most common causes of life-threatening infections in the world. Unfortunately, these infections are increasingly difficult to treat due to the recent explosion in disease caused by methicillin-resistant S. aureus (MRSA) and multi-drug resistant P. aeruginosa (MDRPA). Given their high incidence of causing severe, drug-resistant infections, novel approaches to prevent or treat infections caused by MRSA and MDRPA would have enormous beneficial impact on U.S. and global health. We recently discovered that human platelet microbicidal proteins are microbicidal chemokines, called "kinocidins" to reflect their dual functions. Kinocidins share a consensus structural motif (the ?-core) with classical antimicrobial peptides, and exert rapid and potent microbicidal effects versus pathogens that access the bloodstream, including MRSA and MDRPA. However, kinocidins differ markedly in their overall structural configuration as compared to classical antimicrobial peptides (eg., defensins), the majority of which are cytotoxic or inactivated when released into the bloodstream. Kinocidins are much less cytotoxic to human vascular endothelial cells or erythrocytes in vitro as compared with defensins. In exploring the structural basis for their minimal host toxicity, we made the highly promising discovery that kinocidins disassemble in the context of active infection through cleavage by proteases generated by virulent pathogens, or that emanate from tissues infected by these organisms. Based on this structure-activity paradigm in human kinocidins, we engineered a novel class of polypeptides designed to achieve three critical functions: i) activate in response to signals emanating from virulent organisms or tissues infected thereby; ii) exert potent microbicidal efficacy in relevant contexts, including blood and blood matrices; and iii) have little or no concomitant host cell toxicity as compared with classical antimicrobial peptides. These resulting molecules are termed context-activated protides. We have demonstrated proof of principle by engineering, expressing, and documenting that prototype protides exert 50-fold greater efficacy against MRSA expressing V8 protease than a V8-deficient, avirulent counterpart. Moreover, kinocidin modules retain potent microbicidal activity versus MRSA and MDRPA in whole blood and plasma. Based on these exciting preliminary data, we will assess the feasibility of novel context-activated protides targeting severe MRSA and MDRPA infections. To overcome problems that have contributed to recent failures of antimicrobial peptide therapeutic strategies, and lay the foundations for advancement of context-activated protide technology, our goals for Phase I of the current STTR application are: 1) To generate a combinatorial library of novel context-activated protides using accelerated evolution; 2) To prioritize lead candidate protides for optimal therapeutic index in highly relevant biomatrix assays; and 3) To validate the efficacy of a lead candidate protide in established models of invasive infection. Context-activated protides exploit structural and mechanistic signatures of host defense peptides optimized over millions of years by Nature. This Phase I STTR project is a logical extension of these discoveries, and will validate the feasibility of context-activated protides that target MRSA and MDRPA infections. Outcomes will focus development of lead candidate protides in Phase II of the STTR, to define efficacy against diverse MRSA and MDRPA strains, establish GMP, complete pre-clinical toxicity studies, and submit an IND for phase I clinical trials. This platform technology may also enable otherwise toxic antimicrobial peptides, such as defensins, as therapeutic agents. These advances would represent major breakthroughs in the prevention and treatment of these common and increasingly difficult-to-treat infections.

描述（由申请人提供）：金黄色葡萄球菌和铜绿假单胞菌的抗生素耐药菌株是世界上危及生命的感染的最常见原因之一。不幸的是，由于最近由耐甲氧西林金黄色葡萄球菌（MRSA）和多重耐药铜绿假单胞菌（MDRPA）引起的疾病激增，这些感染越来越难以治疗。鉴于 MRSA 和 MDRPA 引起严重耐药感染的发生率很高，预防或治疗 MDRPA 感染的新方法将对美国和全球健康产生巨大的有益影响。我们最近发现人血小板杀微生物蛋白是杀微生物趋化因子，称为“kinocidins”以反映其双重功能。 Kinocidins 与经典抗菌肽具有共同的结构基序（β-核心），并对进入血液的病原体（包括 MRSA 和 MDRPA）发挥快速而有效的杀菌作用。然而，与经典抗菌肽（例如防御素）相比，激肽杀素的整体结构构型显着不同，其中大多数在释放到血流中时具有细胞毒性或失活。与防御素相比，激肽杀素在体外对人血管内皮细胞或红细胞的细胞毒性要小得多。在探索其最小宿主毒性的结构基础时，我们做出了一个非常有希望的发现，即激肽在主动感染的情况下通过强毒病原体产生的蛋白酶或从这些生物体感染的组织中产生的蛋白酶裂解而分解。基于人类激肽杀素的这种结构-活性范式，我们设计了一类新型多肽，旨在实现三个关键功能：i）响应于由其感染的有毒生物体或组织发出的信号而激活； ii) 在相关环境中发挥有效的杀菌功效，包括血液和血液基质； iii) 与经典抗菌肽相比，几乎没有或没有伴随的宿主细胞毒性。这些产生的分子被称为上下文激活的蛋白质。我们通过工程设计、表达和记录证明了原理证明，原型蛋白对表达 V8 蛋白酶的 MRSA 的功效比 V8 缺陷的无毒对应物高 50 倍。此外，与全血和血浆中的 MRSA 和 MDRPA 相比，kinocidin 模块保留了有效的杀菌活性。基于这些令人兴奋的初步数据，我们将评估针对严重 MRSA 和 MDRPA 感染的新型环境激活蛋白的可行性。为了克服最近导致抗菌肽治疗策略失败的问题，并为背景激活蛋白技术的进步奠定基础，我们当前 STTR 应用第一阶段的目标是： 1）利用加速进化生成新型背景激活蛋白的组合库； 2) 在高度相关的生物基质测定中优先考虑先导候选蛋白质以获得最佳治疗指数； 3) 验证主要候选蛋白在已建立的侵袭性感染模型中的功效。上下文激活的肽利用了大自然数百万年来优化的宿主防御肽的结构和机制特征。第一阶段 STTR 项目是这些发现的逻辑延伸，并将验证针对 MRSA 和 MDRPA 感染的环境激活蛋白的可行性。 STTR II 期的成果将集中于开发主要候选蛋白质，以确定针对不同 MRSA 和 MDRPA 菌株的功效，建立 GMP，完成临床前毒性研究，并提交 I 期临床试验的 IND。该平台技术还可以使其他有毒的抗菌肽（例如防御素）成为治疗剂。这些进展将代表着预防和治疗这些常见且越来越难以治疗的感染的重大突破。