The proteolytically stable peptidomimetic Pam-(Lys-βNSpe)6-NH2 selectively inhibits human neutrophil activation via formyl peptide receptor 2.

Abstract

Immunomodulatory host defense peptides (HDPs) are considered to be lead compounds for novel anti-sepsis and anti-inflammatory agents. However, development of drugs based on HDPs has been hampered by problems with toxicity and low bioavailability due to in vivo proteolysis. Here, a subclass of proteolytically stable HDP mimics consisting of lipidated α-peptide/β-peptoid oligomers was investigated for their effect on neutrophil function. The most promising compound, Pam-(Lys-βNSpe)6-NH2, was shown to inhibit formyl peptide receptor 2 (FPR2) agonist-induced neutrophil granule mobilization and release of reactive oxygen species. The potency of Pam-(Lys-βNSpe)6-NH2 was comparable to that of PBP10, the most potent FPR2-selective inhibitor known. The immunomodulatory effects of structural analogs of Pam-(Lys-βNSpe)6-NH2 emphasized the importance of both the lipid and peptidomimetic parts. By using imaging flow cytometry in primary neutrophils and FPR-transfected cell lines, we found that a fluorescently labeled analog of Pam-(Lys-βNSpe)6-NH2 interacted selectively with FPR2. Furthermore, the interaction between Pam-(Lys-βNSpe)6-NH2 and FPR2 was found to prevent binding of the FPR2-specific activating peptide agonist Cy5-WKYMWM, while the binding of an FPR1-selective agonist was not inhibited. To our knowledge, Pam-(Lys-βNSpe)6-NH2 is the first HDP mimic found to inhibit activation of human neutrophils via direct interaction with FPR2. Hence, we consider Pam-(Lys-βNSpe)6-NH2 to be a convenient tool in the further dissection of the role of FPR2 in inflammation and homeostasis as well as for investigation of the importance of neutrophil stimulation in anti-infective therapy involving HDPs.

• Authors: Sarah Line Skovbakke, Peter M H Heegaard, Camilla J Larsen, Henrik Franzyk, Huamei Forsman, Claes Dahlgren
• Journal: Biochemical pharmacology (Biochem Pharmacol) Vol. 93 Issue 2 Pg. 182-95 (Jan 15 2015) ISSN: 1873-2968 [Electronic] England
• PMID: 25462815 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• FPR2 protein, human
• Peptidomimetics
• Receptors, Formyl Peptide
• Receptors, Lipoxin

Topics

• Dose-Response Relationship, Drug
• HL-60 Cells
• Humans
• Neutrophil Activation (drug effects, physiology)
• Neutrophils (drug effects, metabolism)
• Peptidomimetics (pharmacology)
• Proteolysis (drug effects)
• Receptors, Formyl Peptide (metabolism)
• Receptors, Lipoxin (metabolism)