Facts and speculation about necrotaxis (chemotaxis toward a dying cell).
The name "necrotaxis" has been given to a special type of chemotaxis in which granulocytes and monocytes are attracted to cells in the process of dying. Microirradiation devices (conventional UV and laser) have been used to destroy a target cell. Immediately, leukocytes (neutrophils and monocytes) can be seen to advance towards the damaged cell and to engulf it. Hemoglobin and albumin coagulated in the microbeam are equally necrotactic. The presence of plasma does not seem necessary, as the phenomenon also occurs in a saline environment. The neutrophil nucleus is not necessary for necrotaxis, anucleated cytoplasmic fragments are capable of directionality, rosette formation around the dead cell and phagocytosis. Three specific points are briefly discussed: -- the nature of necrotactic substances -- the recognition mechanism of damaged cells and molecules -- the eventual role of necrotaxis in vivo.
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology; D002470:Cell Survival; D002634:Chemotaxis, Leukocyte; D003593:Cytoplasm / Q000502:physiology; D006098:Granulocytes / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D009000:Monocytes / Q000502:physiology; D009504:Neutrophils / Q000502:physiology; D010587:Phagocytosis; D011817:Rabbits; D051381:Rats