The resolution of inflammation is dependent on recognition and phagocytic removal of apoptotic cells by macrophages. Receptors for apoptotic cells are sensitive to degradation by human neutrophil elastase (HNE). We show in the present study that HNE cleaves macrophage cell surface CD14 and in so doing, reduces phagocytic recognition of apoptotic lymphocytic cells (Mutu 1). Using an improved method of adenovirus-mediated transfection of macrophages with the HNE inhibitor elafin, we demonstrate that elafin overexpression prevents CD14 cleavage and restores apoptotic cell recognition by macrophages. This approach of genetic modification of macrophages could be used to restore apoptotic cell recognition in inflammatory conditions.
- 61D3, monoclonal blocking antibody against CD14
- Ad, adenovirus
- Ad-d1703, control (empty) adenoviral vector
- HNE, human neutrophil elastase
- IL, interleukin
- PBS, phosphate-buffered saline
- PSR, phosphatidylserine receptor