Human Hybrid Antimicrobial Peptides for Corneal Infection: From Molecular Dynamic Simulation to In Vivo Animal Studies

用于治疗角膜感染的人类混合抗菌肽：从分子动力学模拟到体内动物研究

• 批准号: MR/T001674/1
• 负责人: Darren Ting
• 金额: $ 31.5万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FT001674%2F1
• 关键词: Human; Hybrid; Antimicrobial; Peptides; Corneal

Cornea - the transparent window located at the front part of the eye - serves as a critical structure to normal vision and ocular surface defence. Damage to the cornea can lead to permanent scarring with subsequent visual impairment or blindness. Corneal blindness represents the 5th leading cause of blindness globally, affecting approximately 2 million of the world population. Bacterial corneal infection is the most common culprit, with contact lens wear and trauma being the main risk factors. Affected patients are usually debilitated by pain and visual impairment and they often require long-term hospital admissions for intensive antibiotic treatment. However there has been a growing concern on the declining antibiotic efficacy due to emerging resistance of organisms to antibiotic (i.e. antimicrobial resistance) in infections affecting the eyes and other parts of the body. In addition studies have shown the formation of biofilm (a slimy collection of microorganisms that grow on the surface) during bacterial corneal infection, which enhances their virulence and resistance to antibiotic. These issues highlight the urgent need for alternative effective antimicrobial treatment, ideally with anti-biofilm efficacy.Antimicrobial peptides (AMPs) have recently shown promise as potential therapeutic agents due to their unique organisms-killing (i.e. antimicrobial) ability against a wide range of infective organisms such as bacteria, viruses, fungi and parasites. They are important components of the innate immune system that can be found in various parts of the human body, including the ocular surface. They are made up of amino acids (the basic structural units of protein) and are highly positive-charged. They exert their antimicrobial effect by disrupting the negatively charged membrane (outer surface coating) of the microorganisms, culminating in killing of these pathogens.Over the years, we have profiled a spectrum of AMPs from the ocular surface. Notably, some of these human AMPs, including human beta-defensin (HBD)-2, HBD-3 and LL-37 were shown to have higher activity during corneal infection, highlighting their crucial roles in ocular surface defence. The AMPs also exhibit anti-biofilm, anti-cancer, and wound healing properties. However, the potential clinical utility of AMPs is currently limited by several issues such as toxicity to human cells, instability in certain body environment and the susceptibility to breakdown by human / bacterial enzymes. These have led to the innovation of newer generation AMPs, which involves substituting the amino acids within the AMPs or combining two different types of AMPs (hybrid peptide), using human and non-human AMPs sequences. These newer generation AMPs have demonstrated enhanced antimicrobial effect, better stability and lower toxicity to human tissues. Our primary aim is to create and develop efficacious and safe human-derived hybrid AMPs for corneal infection. Recently we have developed several hybrid AMPs with potential efficacy against a variety of bacteria and we now aim to investigate and optimise the efficacy and safety of our hybrid AMPs using a series of experiments, including computer simulation, laboratory experiments with laboratory grown and donated corneal tissues, as well as using tear and blood samples from healthy volunteers. We will then validate the efficacy and safety of our designed AMPs using rationally and ethically designed animal studies, which is an essential step before we could test our AMPs in human clinical trials. These proposed experiments will be conducted collaboratively in UK and Singapore. Successful development of these AMPs could enable us to bridge the gap between fundamental laboratory research and clinical application of AMPs, ultimately benefitting patients with ocular and potentially non-ocular infections. This may also offer a potential solution to the antimicrobial resistance, which is currently emerging as a global health threat.

角膜--位于眼睛前部的透明窗口--是正常视力和眼表防御的关键结构。对角膜的损伤会导致永久性疤痕，继而导致视力受损或失明。角膜失明是全球第五大致盲原因，影响全球约200万人口。细菌性角膜感染是最常见的罪魁祸首，戴隐形眼镜和创伤是主要的危险因素。受影响的患者通常会因疼痛和视力受损而虚弱，他们经常需要长期住院接受密集的抗生素治疗。然而，由于影响眼睛和身体其他部位的感染中出现了对抗生素的抗药性(即抗菌素抗药性)，人们越来越关注抗生素效力的下降。此外，研究表明，在细菌角膜感染期间会形成生物膜(生长在表面的一组粘稠的微生物)，这会增强它们的毒力和对抗生素的抵抗力。这些问题突出了对替代有效的抗菌治疗的迫切需要，理想的是具有抗生物被膜的效果。抗菌肽(AMPs)最近显示出潜在的治疗药物的前景，因为它们对细菌、病毒、真菌和寄生虫等广泛的感染性生物具有独特的杀菌(即抗菌)能力。它们是先天免疫系统的重要组成部分，可以在人体的不同部位找到，包括眼睛表面。它们由氨基酸(蛋白质的基本结构单位)组成，带高度正电荷。它们通过破坏微生物的带负电的膜(外表面涂层)来发挥抗菌作用，最终杀死这些病原体。多年来，我们已经从眼睛表面提取了一系列AMP。值得注意的是，其中一些人AMP，包括人β-防御素(HBD)-2，HBD-3和LL-37，在角膜感染期间显示出更高的活性，突出了它们在眼表防御中的关键作用。AMPS还表现出抗生物膜、抗癌和伤口愈合的特性。然而，目前AMPS的潜在临床应用受到一些问题的限制，如对人体细胞的毒性、某些身体环境的不稳定性以及对人/细菌酶的易感性等。这些都导致了新一代AMPs的创新，包括替换AMPs中的氨基酸或使用人和非人类的AMPs序列结合两种不同类型的AMPs(杂合肽)。这些新一代的AMPS具有更强的抗菌效果、更好的稳定性和对人体组织的低毒性。我们的主要目标是创造和开发有效和安全的人源性杂交AMP来治疗角膜感染。最近，我们开发了几种对多种细菌具有潜在疗效的混合AMPS，现在我们的目标是通过一系列实验来研究和优化我们的混合AMPS的有效性和安全性，这些实验包括计算机模拟、实验室培养和捐赠的角膜组织的实验室实验，以及使用健康志愿者的泪液和血液样本。然后，我们将使用合理和合乎道德的动物实验来验证我们设计的AMP的有效性和安全性，这是我们在人类临床试验中测试我们的AMP之前的关键一步。这些拟议的实验将在英国和新加坡合作进行。这些AMP的成功开发可以使我们能够弥合AMP基础实验室研究和临床应用之间的差距，最终使眼部和潜在的非眼部感染患者受益。这也可能为目前正在成为全球健康威胁的抗菌素耐药性提供一个潜在的解决方案。

项目成果

Evaluation of junior doctors' knowledge of corneal donation and the new opt-out system in England.

英国初级医生角膜捐赠知识和新选择退出制度的评估。

• DOI: 10.1136/postgradmedj-2021-140108
• 发表时间: 2022
• 期刊: Postgraduate medical journal
• 影响因子: 5.1
• 作者: Gopal BP

Real-world experience of using ciclosporin-A 0.1% in the management of ocular surface inflammatory diseases.

• DOI: 10.1136/bjophthalmol-2020-317907
• 发表时间: 2022-08
• 期刊: BRITISH JOURNAL OF OPHTHALMOLOGY
• 影响因子: 4.1
• 作者: Deshmukh, Rashmi;Ting, Darren Shu Jeng;Elsahn, Ahmad;Mohammed, Imran;Said, Dalia G.;Dua, Harminder Singh
• 通讯作者: Dua, Harminder Singh

Diagnostic Performance of Deep Learning in Infectious Keratitis: A Systematic Review and Meta-Analysis Protocol

深度学习在传染性角膜炎中的诊断性能：系统回顾和荟萃分析方案

• DOI: 10.1101/2022.10.11.22280968
• 发表时间: 2022
• 作者: Ong Z

Trainee research network (TRN): a potential global model for promoting research training and outputs among trainees.

受训者研究网络（TRN）：促进受训者研究培训和产出的潜在全球模型。

• DOI: 10.17863/cam.84634
• 发表时间: 2022
• 作者: Ong Z