T cell that kills infected, damaged or cancerous cells
Not to be confused with Natural killer T cell.
Antigen presentation stimulates T cells to become either "cytotoxic" CD8+ cells or "helper" CD4+ cells.
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected by intracellular pathogens (such as viruses or bacteria), or cells that are damaged in other ways.[1]
Most cytotoxic T cells express T-cell receptors (TCRs) that can recognize a specific antigen. An antigen is a molecule capable of stimulating an immune response and is often produced by cancer cells, viruses, bacteria or intracellular signals. Antigens inside a cell are bound to class I MHC molecules, and brought to the surface of the cell by the class I MHC molecule, where they can be recognized by the T cell. If the TCR is specific for that antigen, it binds to the complex of the class I MHC molecule and the antigen, and the T cell destroys the cell.
In order for the TCR to bind to the class I MHC molecule, the former must be accompanied by a glycoprotein called CD8, which binds to the constant portion of the class I MHC molecule. Therefore, these T cells are called CD8+ T cells.
The affinity between CD8 and the MHC molecule keeps the TC cell and the target cell bound closely together during antigen-specific activation. CD8+ T cells are recognized as TC cells once they become activated and are generally classified as having a pre-defined cytotoxic role within the immune system. However, CD8+ T cells also have the ability to make some cytokines, such as TNF-α and IFN-γ, with antitumour and antimicrobial effects.
^Al-Shura AN (2020). "Lymphocytes". Advanced Hematology in Integrated Cardiovascular Chinese Medicine. Elsevier. pp. 41–46. doi:10.1016/b978-0-12-817572-9.00007-0. ISBN 978-0-12-817572-9. S2CID 241913878. Helper T cells/CD4+ •express CD4 glycoproteins on their cell surface, which activate in the presence of peptide antigens on the surface of invading pathogens; •respond immediately to protect the immune system; •secrete different cytokine proteins according to the immune response.
growth of cytotoxicTcells, and in maximizing bactericidal activity of phagocytes such as macrophages and neutrophils. CD4+ cells are mature Th cells that...
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are toxic metals, toxic chemicals, microbe neurotoxins, radiation particles...
blood Tcells. Natural killer Tcells should neither be confused with natural killer cells nor killer Tcells (cytotoxicTcells). The term "NK Tcells" was...
Natural killer cells, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical to the innate immune system...
the cytotoxicTcells (CD8-positive) subset, similar populations appear to exist for both the helper Tcells (CD4-positive) and the cytotoxicTcells. Primary...
antigen on a cell's surface, Tcells bind to it and become activated, then proceed to proliferate and become cytotoxic. CAR Tcells destroy cells through several...
Gamma delta Tcells (γδ Tcells) are Tcells that have a γδ T-cell receptor (TCR) on their surface. Most Tcells are αβ (alpha beta) Tcells with TCR composed...
forms of helper Tcells (CD4+) and cytotoxicTcells (CD8+). Any naive Tcell is considered immature and, unlike activated or memory Tcells, has not encountered...
helper and cytotoxicT-cells can control viral infections by secreting interferons. CytotoxicTcells usually kill virally infected cells. However, they...
co-receptor for the T-cell receptor (TCR). Along with the TCR, the CD8 co-receptor plays a role in Tcell signaling and aiding with cytotoxicTcell-antigen interactions...
into helper T cells, memory Tcells, cytotoxicTcells), B cells (subdivided into plasma cells and memory B cells), and natural killer cells. Historically...
found in the granules of natural killer cells (NK cells) and cytotoxicTcells. It is secreted by these cells along with the pore forming protein perforin...
immunological imprinting. A similar phenomenon has been described in cytotoxicTcells (CTL). It has been demonstrated that during a second infection by...
CD4 and CD8, which are, in general, used as markers for helper and cytotoxicTcells, respectively. These molecules are defined in combination with CD3+...
secreted by adaptive immune cells, more specifically CD4+ T helper 1 (Th1) cells, natural killer (NK) cells, and CD8+ cytotoxicTcells. The expression of type...
lymphoma (IVTL) in which the neoplastic cells are primarily, if not exclusively, a type of t-cell termed cytotoxicT-cells. Because of their similarities and...
MHC class I attract T-lymphocytes called killer T-cells (also referred to as CD8-positive or cytotoxicT-cells) that destroy cells. Some new work has proposed...
such as lymphocytes, macrophages, dendritic cells, natural killer cells, and cytotoxicT lymphocytes work together to defend the body against cancer by targeting...
receptor-bearing cells, e.g. cytotoxicTcells. - soluble FasL: increasing the effectivity of the system - soluble Fas: FasL blockage on the surface of other cells (no...
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