Identification of heptapeptides targeting a lethal bacterial strain in septic mice through an integrative approach

Abstract

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.

Phage‐displayed heptapeptide sequence conjugation significantly improves the specific targeting ability of antimicrobial peptides against Staphylococcus aureus

“…The hybrid peptides F6P6 and P6F6 showed antibacterial activity against C. perfringens but did not kill other bacteria. Zhang et al developed an antimicrobial peptide against a specific septic pathogen based on phage display technology, suggesting that it is feasible to design specifically targeted sepsis 35 . The specifically targeted antimicrobial peptide VTK‐LL37 effectively killed pathogenic bacteria and inhibited biofilm formation.…”

Synthetic biology-inspired cell engineering in diagnosis, treatment and drug development

“…276 Recently, E. coli MSI001, a lethal strain, was isolated from mice; the strain was used for screening bacteria-binding heptapeptides based on an integrative bioinformatics approach, phage display technology, and high-throughput sequencing. 277 Yeast is another promising cell factory for the production of peptides. Apidaecins, a series of small and proline-rich antimicrobial peptides act as a defense system against many drug-resistant bacteria.…”