143 HB‐107, A Non‐Antimicrobial Fragment of Cecropin B, Accelerates Murine Wound Repair

Abstract

Intact skin represents the first line of defense against microbial pathogens. Effectors of innate immunity such as antimicrobial peptides are important when this barrier is breached due to infection or injury. Antimicrobial peptides can kill microbes directly, however several investigations have suggested they can also modify host cell behaviors to promote wound repair. It is unclear whether the ability of these molecules to positively influence wound repair is dependent on their antimicrobial function or on their ability to influence the host. To investigate this, the microbial killing capacity of specific antimicrobial peptide fragments was determined and compared with their ability to affect wound repair in a murine model of aseptic full‐thickness excisional injury. HB‐107, a peptide fragment derived from Cecropin B, lacks antimicrobial activity yet showed up to 64% improvement in wound closure at day13 when compared to either scrambled peptide or vehicle controls. This effect was comparable to that seen after treatment with currently accepted therapy. Histological evaluation of wounds treated with HB‐107 displayed keratinocyte hyperplasia and increased leukocyte infiltration compared to controls. To explore the mechanism for these findings, we tested the ability of HB‐107 to stimulate IL‐8 secretion. HB‐107 peptide was able to stimulate IL‐8 release from cultured dermal microvascular endothelial cells when compared to scrambled peptide control or other peptides derived from Cecropin B. Taken together, this data confirms that antimicrobial peptides can function as important effectors of wound repair independent of antimicrobial function.