Apolipoproteins and apolipoprotein mimetic peptides modulate phagocyte trafficking through chemotactic activity

J Biol Chem. 2012 Dec 21;287(52):43730-40. doi: 10.1074/jbc.M112.377192. Epub 2012 Nov 1.


The plasma lipoprotein-associated apolipoproteins (apo) A-I and apoE have well described anti-inflammatory actions in the cardiovascular system, and mimetic peptides that retain these properties have been designed as therapeutics. The anti-inflammatory mechanisms of apolipoprotein mimetics, however, are incompletely defined. Whether circulating apolipoproteins and their mimetics regulate innate immune responses at mucosal surfaces, sites where transvascular emigration of leukocytes is required during inflammation, remains unclear. Herein, we report that Apoai(-/-) and Apoe(-/-) mice display enhanced recruitment of neutrophils to the airspace in response to both inhaled lipopolysaccharide and direct airway inoculation with CXCL1. Conversely, treatment with apoA-I (L-4F) or apoE (COG1410) mimetic peptides reduces airway neutrophilia. We identify suppression of CXCR2-directed chemotaxis as a mechanism underlying the apolipoprotein effect. Pursuing the possibility that L-4F might suppress chemotaxis through heterologous desensitization, we confirmed that L-4F itself induces chemotaxis of human PMNs and monocytes. L-4F, however, fails to induce a calcium flux. Further exploring structure-function relationships, we studied the alternate apoA-I mimetic L-37pA, a bihelical analog of L-4F with two Leu-Phe substitutions. We find that L-37pA induces calcium and chemotaxis through formyl peptide receptor (FPR)2/ALX, whereas its D-stereoisomer (i.e. D-37pA) blocks L-37pA signaling and induces chemotaxis but not calcium flux through an unidentified receptor. Taken together, apolipoprotein mimetic peptides are novel chemotactic agents that possess complex structure-activity relationships to multiple receptors, displaying anti-inflammatory efficacy against innate immune responses in the airway.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Apolipoprotein A-I / genetics
  • Apolipoprotein A-I / pharmacology*
  • Apolipoproteins E / pharmacology*
  • Biomimetic Materials / pharmacology*
  • Calcium Signaling / drug effects
  • Chemokine CXCL1 / pharmacology
  • Chemotaxis / drug effects*
  • Chemotaxis / physiology
  • Female
  • HEK293 Cells
  • Humans
  • Mice
  • Mice, Knockout
  • Neutrophil Infiltration / drug effects*
  • Neutrophil Infiltration / physiology
  • Neutrophils / cytology
  • Neutrophils / metabolism*
  • Peptides / pharmacology*
  • Receptors, Formyl Peptide / genetics
  • Receptors, Formyl Peptide / metabolism
  • Receptors, Lipoxin / genetics
  • Receptors, Lipoxin / metabolism
  • Structure-Activity Relationship


  • Apolipoprotein A-I
  • Apolipoproteins E
  • COG1410
  • CXCL1 protein, human
  • Chemokine CXCL1
  • Cxcl1 protein, mouse
  • FPR2 protein, human
  • L-4F peptide
  • Peptides
  • Receptors, Formyl Peptide
  • Receptors, Lipoxin
  • formyl peptide receptor 2, mouse