Cues for apoptotic cell engulfment: eat-me, don't eat-me and come-get-me signals.
Efficient elimination of cells undergoing programmed cell death is crucial for normal tissue homeostasis and for the regulation of immune responses. This review examines unique signals presented by apoptotic cells and the mechanisms by which phagocytes recognize and respond to these signals to orchestrate the selective and rapid removal of apoptotic cells. Such unique signals include direct and indirect 'eat-me' markers on the apoptotic cell surface, the absence of 'don't eat-me' markers normally found on living cells and soluble 'come-get-me' signals secreted by apoptotic cells to attract phagocytes to sites of apoptotic cell death. Once apoptotic cells are identified, their uptake by phagocytes further depends on the molecular machinery highly conserved from Caenorhabditis elegans to mammals.
Grimsley
Cynthia
C
Carter Immunology Center and the Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.
Ravichandran
Kodi S
KS
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001327:Autoimmune Diseases / Q000503:physiopathology; D006801:Humans; D007113:Immunity, Innate; D010586:Phagocytes / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D011971:Receptors, Immunologic / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
D011971:Receptors, Immunologic; C028495:phagocytosis receptor