Guangdong Provincial Key Laboratory of Proteomics, State Key Laboratory of Organ Failure Research, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Signal Transduct Target Ther. 2022 Jul 25;7(1):245. doi: 10.1038/s41392-022-01035-6.
Effectively killing pathogenic bacteria is key for the treatment of sepsis. Although various anti-infective drugs have been used for the treatment of sepsis, the therapeutic effect is largely limited by the lack of a specific bacterium-targeting delivery system. This study aimed to develop antibacterial peptides that specifically target pathogenic bacteria for the treatment of sepsis. The lethal bacterial strain Escherichia coli MSI001 was isolated from mice of a cecal ligation and puncture (CLP) model and was used as a target to screen bacterial binding heptapeptides through an integrative bioinformatics approach based on phage display technology and high-throughput sequencing (HTS). Heptapeptides binding to E. coli MSI001 with high affinity were acquired after normalization by the heptapeptide frequency of the library. A representative heptapeptide VTKLGSL (VTK) was selected for fusion with the antibacterial peptide LL-37 to construct the specific-targeting antibacterial peptide VTK-LL37. We found that, in comparison with LL37, VTK-LL37 showed prominent bacteriostatic activity and an inhibitive effect on biofilm formation in vitro. In vivo experiments demonstrated that VTK-LL37 significantly inhibited bacterial growth, reduced HMGB1 expression, alleviated lesions of vital organs and improved the survival of mice subjected to CLP modeling. Furthermore, membrane DEGP and DEGQ were identified as VTK-binding proteins by proteomic methods. This study provides a novel strategy for targeted pathogen killing, which is helpful for the treatment of sepsis in the era of precise medicine.
有效杀灭致病菌是治疗败血症的关键。尽管已经使用了各种抗感染药物来治疗败血症，但治疗效果在很大程度上受到缺乏针对特定细菌的靶向递送系统的限制。本研究旨在开发专门针对致病菌的抗菌肽来治疗败血症。从盲肠结扎穿刺（CLP）模型小鼠中分离出致死性细菌菌株大肠杆菌 MSI001，并将其作为靶标，通过基于噬菌体展示技术和高通量测序（HTS）的综合生物信息学方法筛选对细菌具有高亲和力的结合七肽。通过对文库中七肽的频率进行归一化，获得与 E. coli MSI001 结合的高亲和力七肽。选择具有代表性的七肽 VTKLGSL（VTK）与抗菌肽 LL-37 融合，构建特异性靶向抗菌肽 VTK-LL37。与 LL37 相比，我们发现 VTK-LL37 在体外表现出突出的抑菌活性和抑制生物膜形成的作用。体内实验表明，VTK-LL37 能显著抑制细菌生长，降低 HMGB1 表达，减轻重要器官损伤，提高 CLP 造模小鼠的存活率。此外，通过蛋白质组学方法鉴定出 DEGP 和 DEGQ 是 VTK 的结合蛋白。这项研究为靶向病原体杀伤提供了一种新策略，有助于在精准医学时代治疗败血症。
