Macrophage phagocytosis of wound neutrophils

• Published in: Journal of leukocyte biology Vol. 65; no. 1; pp. 35 - 42
• Main Authors: Meszaros, Adriana J., Reichner, Jonathan S., Albina, Jorge E.
• Format: Journal Article
• Language: English
• Published: United States Society for Leukocyte Biology 01.01.1999
• Subjects: Animals; apoptosis; Apoptosis - physiology; Cells, Cultured; inflammation; Ligands; Macrophages, Peritoneal - immunology; Macrophages, Peritoneal - pathology; Male; Neutrophils - immunology; Neutrophils - pathology; Phagocytosis - physiology; Rats; Rats, Inbred F344; Receptors, Cell Surface - metabolism; Receptors, Cell Surface - physiology; wound healing; Wounds and Injuries - immunology; Wounds and Injuries - pathology
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.65.1.35

Resolution of acute inflammation is thought to require the recognition and phagocytosis of apoptotic neutrophils (PMN) through receptor‐ligand interactions with macrophages (Mϕ). 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 Mϕ. 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 Mϕ. All three Mϕ 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‐Mϕ phagocytosis of wound PMN, and identify distinct receptor utilization by wound and other Mϕ to ingest wound PMN. J. Leukoc. Biol. 65:35–42; 1999.