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Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
Published on: December 27, 2016
Clearing the dead: apoptotic cell sensing, recognition, engulfment, and digestion
Amelia Hochreiter-Hufford1, Kodi S Ravichandran
1Department of Microbiology, Immunology and Cancer Biology, Center for Cell Clearance and Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908, USA.
Cold Spring Harbor Perspectives in Biology
|January 4, 2013
Summary
Efficient clearance of apoptotic cells prevents inflammation. This study details the "find me" and "eat me" signals, receptor recognition, and phagocyte responses crucial for silent engulfment of cellular corpses.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Apoptotic cell clearance is vital for preventing secondary necrosis, inflammation, and autoimmunity.
- Efficient removal of cellular corpses is essential in tissues with high cell turnover.
- Dysfunctional apoptotic cell clearance is linked to autoimmune diseases.
Purpose of the Study:
- To review and synthesize recent advancements in understanding in vivo apoptotic cell clearance mechanisms.
- To elucidate the molecular and cellular processes governing the recognition and engulfment of apoptotic cells.
- To highlight the importance of "immunologically silent" clearance in maintaining tissue homeostasis.
Main Methods:
- Literature review focusing on recent findings in apoptotic cell clearance.
- Analysis of signaling pathways involved in phagocyte recognition and engulfment.
- Discussion of "find me" and "eat me" signals and their receptors.
Main Results:
- Detailed explanation of the multi-step process of apoptotic cell clearance.
- Identification of key molecular players, including signals and receptors.
- Emphasis on the role of phagocyte responses in ensuring immune tolerance during clearance.
Conclusions:
- Significant progress has been made in understanding the intricate mechanisms of apoptotic cell clearance.
- The coordinated action of signals, receptors, and phagocyte responses ensures efficient and silent removal of apoptotic cells.
- Further research into these mechanisms holds potential for therapeutic interventions in inflammatory and autoimmune conditions.
Related Concept Videos
01:17Phagocytosis of Apoptotic Cells
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
01:30Overview of Cell Death
Cell death is an essential process where the body gets rid of old or damaged cells. Cell proliferation and death need to be balanced, as an imbalance between the two may lead to cancer or autoimmune diseases.
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...
01:22Cellular Injury V: Apoptosis and Autophagy
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...
01:18Autophagic Cell Death
Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
01:17The Extrinsic Apoptotic Pathway
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
01:30Apoptosis
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.