Immune cell death is a process where the death of a cell triggers an immune response. This isn't just any cell death; it's a regulated event that actively involves the immune system. The dying cell releases signals that alert and activate immune cells, leading to an immune reaction. This differs from accidental cell death, where the immune system might respond, but the cell's death isn't a direct cause.
Types and Mechanisms
Several types of cell death can trigger immune responses, including:
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Apoptosis: A programmed form of cell death characterized by cell shrinkage and membrane blebbing. While it can be immunogenic, it isn't always. Apoptosis that is immunogenic is often called immunogenic apoptosis or ICD. [ICD or immunogenic apoptosis is a form of cell death resulting in a regulated activation of the immune response. This cell death is characterized by apoptotic morphology, maintaining membrane integrity.](Reference: Provided text)
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Necroptosis: A programmed, inflammatory form of cell death, which is strongly immunogenic.
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Pyroptosis: A highly inflammatory programmed cell death, often associated with infection.
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Immunogenic Cell Death (ICD): This encompasses several types of regulated cell death that specifically elicit an immune response. ICD involves changes in the cell surface and the release of soluble mediators that activate the immune system. [Immunogenic cell death (ICD) involves changes in the composition of the cell surface as well as the release of soluble mediators, occurring in a defined...](Reference: Pubmed) [Immunogenic cell death (ICD) represents a form of regulated cell death (RCD) capable of enhancing tumor immunogenicity and activating tumor-specific innate and...](Reference: Frontiers in Immunology) [Immunogenic cell death is any type of cell death eliciting an immune response. Both accidental cell death and regulated cell death can result in immune...](Reference: Wikipedia)
The exact mechanisms vary depending on the type of cell death and the triggers involved. However, a common theme is the release of damage-associated molecular patterns (DAMPs) from the dying cell. These DAMPs are recognized by immune cells, activating them and initiating an immune response. [Dying mammalian cells emit numerous signals that interact with the host to dictate the immunological correlates of cellular stress and death...](Reference: Nature Immunology) [Immunogenic cell death (ICD) is defined by the chronic exposure of DAMPs to the immune system, which may drive autoimmunity and promote...](Reference: PMC)
Significance in Immunity
Immune cell death plays a crucial role in various aspects of the immune system, including:
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Infection Control: The death of infected cells can help eliminate pathogens and activate immune responses to clear the infection. [Host cell death is an intrinsic immune defense mechanism in response to microbial infection. However, bacterial pathogens use many...](Reference: JCB)
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Cancer Immunotherapy: Inducing ICD in tumor cells is a promising strategy in cancer immunotherapy, aiming to boost the immune system's ability to recognize and destroy cancer cells. [Emerging role of immunogenic cell death in cancer immunotherapy](Reference: Frontiers in Immunology)
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Autoimmunity: While beneficial in many cases, uncontrolled or dysregulated immune cell death can contribute to autoimmune diseases. [Immunogenic cell death (ICD) is defined by the chronic exposure of DAMPs to the immune system, which may drive autoimmunity and promote...](Reference: PMC)
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Neuroinflammation: Immune cell death plays a complex role in neuroinflammation, potentially contributing to both protective and damaging effects. [Innate Immune Cell Death in Neuroinflammation and Alzheimer's...](Reference: Pubmed)
