Modulation of phagocytosis of apoptotic neutrophils by supernatant from dexamethasone-treated macrophages and annexin-derived peptide Ac2–26

P Maderna, S Yona, M Perretti… - The Journal of …, 2005 - journals.aai.org
The Journal of Immunology, 2005journals.aai.org
Phagocytic clearance of apoptotic leukocytes plays an important role in the resolution of
inflammation. The glucocorticoid-inducible protein annexin 1 and annexin 1-derived
peptides show potent anti-inflammatory responses in acute and chronic inflammation. In this
study, we report that the annexin 1-derived peptide (Ac 2–26) significantly stimulates
nonphlogistic phagocytosis of apoptotic polymorphonuclear leukocytes (PMNs) by human
monocyte-derived macrophages (Mφ). Peptide Ac 2–26-stimulated phagocytosis is …
Abstract
Phagocytic clearance of apoptotic leukocytes plays an important role in the resolution of inflammation. The glucocorticoid-inducible protein annexin 1 and annexin 1-derived peptides show potent anti-inflammatory responses in acute and chronic inflammation. In this study, we report that the annexin 1-derived peptide (Ac 2–26) significantly stimulates nonphlogistic phagocytosis of apoptotic polymorphonuclear leukocytes (PMNs) by human monocyte-derived macrophages (Mφ). Peptide Ac 2–26-stimulated phagocytosis is accompanied by rearrangement of the Mφ actin cytoskeleton. To investigate the potential role of endogenous annexin on clearance of apoptotic cells, Mφ were cultured for 5 days in the presence of dexamethasone. Supernatants collected from dexamethasone-treated Mφ significantly enhanced the ability of naive Mφ to engulf apoptotic PMNs. This effect was blocked by an annexin blocking Ab, by immunodepletion of the supernatants, and by the formyl peptide receptor/lipoxin receptor antagonist Boc1. In addition, we show that bone marrow-derived Mφ from annexin 1-null mice present a 40% decreased phagocytosis of apoptotic PMNs compared with cells taken from littermate controls. In conclusion, these results emphasize the pivotal role of annexin 1 as mediator for clearance of apoptotic cells and expand its potential therapeutic role in controlling inflammatory diseases.
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