Multivalent Display of Antimicrobial Peptides on Plant Virus Scaffolds Enhances Killing of Drug-Resistant Bacteria

Area of Science:

• Biotechnology
• Materials Science
• Infectious Diseases

Background:

• Multidrug-resistant (MDR) bacteria present a critical global health threat.
• Antimicrobial peptides (AMPs) show potential against MDR bacteria but face challenges like reduced efficacy, toxicity, and poor in vivo stability.
• Developing novel strategies is crucial to overcome antimicrobial resistance.

Purpose of the Study:

• To develop a plant virus-based platform for enhanced antimicrobial peptide (AMP) delivery.
• To create rod-based peptide grids (RPG) using the Potato virus X (PVX) scaffold for modular AMP display.
• To evaluate the efficacy, stability, and safety of the RPG platform against MDR bacteria.

Main Methods:

• Engineered Potato virus X (PVX) into a rod-based peptide grid (RPG) scaffold.
• Conjugated antimicrobial peptides (AMPs) multivalently onto the RPG platform.
• Assessed RPG-AMP efficacy against MDR pathogens in vitro and in vivo.
• Evaluated RPG stability in serum and resistance to proteases.
• Determined cytotoxicity of RPG on mammalian cells.

Main Results:

• RPG enhanced AMP efficacy by over 9700-fold, maintaining activity under in vivo salt conditions.
• RPG rapidly eradicated MDR pathogens within 10-30 minutes, outperforming last-resort antibiotics.
• RPG exhibited low cytotoxicity to mammalian cells.
• RPG demonstrated stability in serum and protease resistance due to its structural complexity.
• Multivalent display of AMP variants resulted in enhanced broad-spectrum killing at lower doses.

Conclusions:

• Plant virus-AMP conjugates, specifically RPG, represent a safe, potent, and broad-spectrum antimicrobial platform.
• The RPG platform offers a versatile strategy to combat antibiotic resistance.
• This approach overcomes limitations of traditional AMPs, paving the way for clinical translation.