DEL-1 promotes macrophage efferocytosis and clearance of inflammation

Nat Immunol. 2019 Jan;20(1):40-49. doi: 10.1038/s41590-018-0249-1. Epub 2018 Nov 19.

Abstract

Resolution of inflammation is essential for tissue homeostasis and represents a promising approach to inflammatory disorders. Here we found that developmental endothelial locus-1 (DEL-1), a secreted protein that inhibits leukocyte-endothelial adhesion and inflammation initiation, also functions as a non-redundant downstream effector in inflammation clearance. In human and mouse periodontitis, waning of inflammation was correlated with DEL-1 upregulation, whereas resolution of experimental periodontitis failed in DEL-1 deficiency. This concept was mechanistically substantiated in acute monosodium-urate-crystal-induced inflammation, where the pro-resolution function of DEL-1 was attributed to effective apoptotic neutrophil clearance (efferocytosis). DEL-1-mediated efferocytosis induced liver X receptor-dependent macrophage reprogramming to a pro-resolving phenotype and was required for optimal production of at least certain specific pro-resolving mediators. Experiments in transgenic mice with cell-specific overexpression of DEL-1 linked its anti-leukocyte-recruitment action to endothelial cell-derived DEL-1 and its efferocytic/pro-resolving action to macrophage-derived DEL-1. Thus, the compartmentalized expression of DEL-1 facilitates distinct homeostatic functions in an appropriate context that can be harnessed therapeutically.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Calcium-Binding Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Adhesion Molecules
  • Cellular Reprogramming
  • Cytokines / metabolism
  • Gene Expression Regulation
  • Humans
  • Inflammation / chemically induced
  • Inflammation / immunology*
  • Intercellular Signaling Peptides and Proteins
  • K562 Cells
  • Liver X Receptors / metabolism
  • Macrophages / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neutrophils / immunology*
  • Periodontitis / immunology*
  • Phagocytosis

Substances

  • Calcium-Binding Proteins
  • Carrier Proteins
  • Cell Adhesion Molecules
  • Cytokines
  • EDIL3 protein, human
  • Edil3 protein, mouse
  • Intercellular Signaling Peptides and Proteins
  • Liver X Receptors