Macrophage phagocytosis of wound neutrophils.
Resolution of acute inflammation is thought to require the recognition and phagocytosis of apoptotic neutrophils (PMN) through receptor-ligand interactions with macrophages (Mphi). This hypothesis was tested in rat wounds by quantifying apoptosis in freshly harvested and aged-in-culture PMN taken from wounds 1-3 days after injury and by using these wound PMN as phagocytic targets for wound, immune-activated peritoneal, and resident peritoneal Mphi. Less than 6% of freshly harvested PMN exhibited characteristics of apoptosis. On aging in culture, day 1 PMN did not undergo apoptosis, whereas 41+/-1 and 29+/-1% of day 2 and 3 PMN, respectively, developed apoptosis, which corresponded to increased ingestion by Mphi. All three Mphi populations engaged different receptor-ligand pairs for the recognition and phagocytosis of PMN. Results indicate the resistance of early wound PMN to age-induced apoptosis, demonstrate wound-Mphi phagocytosis of wound PMN, and identify distinct receptor utilization by wound and other Mphi to ingest wound PMN.
Meszaros
A J
AJ
Department of Surgery, Rhode Island Hospital and Brown University School of Medicine, Providence 02903, USA. Adriana_Meszaros@brown.edu
Reichner
J S
JS
Albina
J E
JE
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002478:Cells, Cultured; D008024:Ligands; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000276:immunology / Q000473:pathology*; D010587:Phagocytosis / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D011956:Receptors, Cell Surface / Q000378:metabolism / Q000502:physiology; D014947:Wounds and Injuries / Q000276:immunology* / Q000473:pathology*
D008024:Ligands; D011956:Receptors, Cell Surface