Novel chimeric peptide with enhanced cell specificity and anti-inflammatory activity

Area of Science:

• Biochemistry
• Microbiology
• Immunology

Background:

• Antimicrobial peptides (AMPs) are crucial in innate immunity.
• Developing effective AMPs against drug-resistant bacteria is a global health priority.
• Chimeric design offers a strategy to enhance AMP efficacy and safety.

Purpose of the Study:

• To design and characterize a novel chimeric AMP, Hn-Mc.
• To evaluate its antibacterial spectrum, including against drug-resistant strains.
• To assess its cytotoxicity, anti-inflammatory potential, and mechanism of action.

Main Methods:

• Hn-Mc was designed by combining HPA3NT3 and melittin.
• Minimal inhibitory concentrations (MICs) were determined for susceptible and resistant bacteria.
• Hemolysis, cytotoxicity, and giant unilamellar vesicle assays were performed.
• In vivo antibacterial activity was tested in a mouse model.
• Inhibition of LPS-induced cytokine expression was analyzed via TLR interaction.

Main Results:

• Hn-Mc demonstrated potent antibacterial activity (1-2 μM MICs) against drug-susceptible and drug-resistant bacteria.
• Hemolysis and cytotoxicity were significantly lower than parent peptides, indicating high cell selectivity.
• Membrane damage was identified as the primary mechanism of bacterial cell death.
• Hn-Mc showed efficacy in vivo against drug-resistant bacterial infections.
• The peptide inhibited LPS-induced cytokine expression by blocking LPS-TLR interaction.

Conclusions:

• The chimeric AMP Hn-Mc possesses broad-spectrum antibacterial activity and low toxicity.
• Its mechanism involves bacterial membrane disruption.
• Hn-Mc exhibits anti-inflammatory effects by modulating TLR signaling.
• This peptide represents a promising candidate for pharmaceutical development as an antimicrobial and anti-inflammatory agent.