Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r

Area of Science:

• Biochemistry
• Microbiology
• Pharmacology

Background:

• Antimicrobial peptides (AMPs) are a promising class of therapeutics for infectious diseases.
• Novel AMPs are needed to combat resistant microbial strains.
• HLR1r, derived from human lactoferrin, is investigated for its therapeutic potential.

Purpose of the Study:

• To characterize the novel antimicrobial peptide HLR1r.
• To evaluate its efficacy against Gram-negative and Gram-positive bacteria, including MRSA, and Candida albicans.
• To assess its anti-inflammatory properties and safety profile.

Main Methods:

• In vitro microbicidal assays were performed to determine the minimum inhibitory concentration (MIC) of HLR1r.
• Inhibition of pro-inflammatory cytokine secretion (TNF-α, IL-6, PAI-1) was measured in human cell lines.
• In vivo efficacy was tested in murine models of cutaneous candidiasis and rat models of MRSA-infected wounds, along with ex vivo pig skin models.

Main Results:

• HLR1r exhibited broad-spectrum microbicidal activity against bacteria and yeast, with MICs ranging from 3-50μg/ml.
• The peptide demonstrated significant anti-inflammatory effects by inhibiting TNF-α, IL-6, and PAI-1 secretion without cytotoxicity.
• HLR1r showed pronounced anti-infective effects in experimental models of candidiasis and MRSA-infected wounds.

Conclusions:

• HLR1r possesses potent antimicrobial and anti-inflammatory properties.
• It is effective in both in vitro and in vivo models of infection.
• HLR1r represents a potential new therapeutic agent for the local treatment of skin infections.