Search results
Results from the WOW.Com Content Network
Macrophages are the predominant cells involved in creating the progressive plaque lesions of atherosclerosis. [89] Focal recruitment of macrophages occurs after the onset of acute myocardial infarction. These macrophages function to remove debris, apoptotic cells and to prepare for tissue regeneration. [90]
Phagocytosis (from Ancient Greek φαγεῖν (phagein) 'to eat' and κύτος (kytos) 'cell') is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte.
Pathogenic cells such as bacteria can be opsonised by antibodies or complement factors, enabling their phagocytosis and phagoptosis by macrophages and neutrophils. "Aged" erythrocytes and neutrophils, as well as "activated" platelets, neutrophils and T-cells, are thought to be phagocytosed alive by macrophages.
Apoptosis is a form of programmed cell death that is used by the body to remove unwanted, damaged, or senescent cells from tissues. Removal of apoptotic cells is carried out via phagocytosis by white blood cells such as macrophages and dendritic cells.
A cell undergoing apoptosis shows a series of characteristic morphological changes. Early alterations include: Cell shrinkage and rounding occur because of the retraction of lamellipodia and the breakdown of the proteinaceous cytoskeleton by caspases. [56] The cytoplasm appears dense, and the organelles appear tightly packed. [citation needed]
Efferocytosis can be performed not only by 'professional' phagocytic cells such as macrophages or dendritic cells, but also by many other cell types including epithelial cells and fibroblasts. To distinguish them from living cells, apoptotic cells carry specific 'eat me' signals, such as the presence of phosphatidyl serine (resulting from ...
In cell biology, a phagosome is a vesicle formed around a particle engulfed by a phagocyte via phagocytosis. Professional phagocytes include macrophages, neutrophils, and dendritic cells (DCs). [1] A phagosome is formed by the fusion of the cell membrane around a microorganism, a senescent cell or an apoptotic cell.
Dendritic cells and macrophages are not so fast, and phagocytosis can take many hours in these cells. Macrophages are slow and untidy eaters; they engulf huge quantities of material and frequently release some undigested back into the tissues. This debris serves as a signal to recruit more phagocytes from the blood. [27]