The human cationic host defense peptide LL-37 mediates contrasting effects on apoptotic pathways in different primary cells of the innate immune system

Barlow, P. G.; Li, Yuexin; Wilkinson, Thomas S; Bowdish, Dawn M E; Lau, Y Elaine; Cosseau, Celine; Haslett, Christopher; Simpson, A John; Hancock, Robert E W; Davidson, Donald J

Abstract

The human cathelicidin LL-37 is a cationic host defense peptide (antimicrobial peptide) expressed primarily by neutrophils and epithelial cells. This peptide, up-regulated under conditions of inflammation, has immunomodulatory and antimicrobial functions. We demonstrate that LL-37 is a potent inhibitor of human neutrophil apoptosis, signaling through P2X(7) receptors and G-protein-coupled receptors other than the formyl peptide receptor-like-1 molecule. This process involved modulation of Mcl-1 expression, inhibition of BID and procaspase-3 cleavage, and the activation of phosphatidylinositol-3 kinase but not the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway. In contrast to the inhibition of neutrophil apoptosis, LL-37 induced apoptosis in primary airway epithelial cells, demonstrating alternate consequences of LL-37-mediated modulation of apoptotic pathways in different human primary cells. We propose that these novel immunomodulatory properties of LL-37 contribute to peptide-mediated enhancement of innate host defenses against acute infection and are of considerable significance in the development of such peptides and their synthetic analogs as potential therapeutics for use against multiple antibiotic-resistant infectious diseases.

Citation

Barlow, P. G., Li, Y., Wilkinson, T. S., Bowdish, D. M. E., Lau, Y. E., Cosseau, C., Haslett, C., Simpson, A. J., Hancock, R. E. W., & Davidson, D. J. (2006). The human cationic host defense peptide LL-37 mediates contrasting effects on apoptotic pathways in different primary cells of the innate immune system. Journal of Leukocyte Biology, 80(3), 509-520. https://doi.org/10.1189/jlb.1005560

• Journal Article Type: Article
• Acceptance Date: May 9, 2006
• Online Publication Date: Jul 20, 2006
• Publication Date: Sep 30, 2006
• Deposit Date: Mar 27, 2012
• Journal: Journal of Leukocyte Biology
• Print ISSN: 0741-5400
• Publisher: Society for Leukocyte Biology
• Peer Reviewed: Peer Reviewed
• Volume: 80
• Issue: 3
• Pages: 509-520
• DOI: https://doi.org/10.1189/jlb.1005560
• Keywords: cathelicidin ;antimicrobial peptide; neutrophil; epithelial cell; FPRL-1; P2X7
• Public URL: http://researchrepository.napier.ac.uk/id/eprint/5181
• Publisher URL: http://dx.doi.org/10.1189/jlb.1005560