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Induced-self Antigen
Induced-self antigen is a marker of abnormal self, which can be recognized upon infected (in particular, virus-infected) and transformed cells. Therefore, the recognition of "induced self" is an important strategy for surveillance of infection or tumor transformation - it results in elimination of the affected cells by activated NK cells or other immunological mechanisms. Similarly γδ T cells can recognize induced-self antigens expressed on cells under stress conditions. Receptors Probably the most studied receptor involved in recognition of induced-self antigens is NKG2D NKG2D is an activating receptor (transmembrane protein) belonging to the NKG2 family of C-type lectin-like receptors. NKG2D is encoded by ''KLRK1'' (killer cell lectin like receptor K1) gene which is located in the NK-gene complex (NKC) situated .... It is an activating receptor which is expressed on NK cells and subsets of T and NKT cells. NKG2D can bind proteins at the surface of most cells that are not nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. The term ''antigen'' originally referred to a substance that is an antibody generator. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, or nucleic acids. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Killer Cell
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 that belong to the rapidly expanding family of known innate lymphoid cells (ILC) and represent 5–20% of all circulating lymphocytes in humans. The role of NK cells is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response. NK cells provide rapid responses to virus-infected cell and other intracellular pathogens acting at around 3 days after infection, and respond to tumor formation. Typically, immune cells detect the major histocompatibility complex (MHC) presented on infected cell surfaces, triggering cytokine release, causing the death of the infected cell by lysis or apoptosis. NK cells are unique, however, as they have the ability to recognize and kill stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named "natural killers" because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
γδ T Cells
Gamma delta T cells (γδ T cells) are T cells that have a γδ T-cell receptor (TCR) on their surface. Most T cells are αβ (alpha beta) T cells with TCR composed of two glycoprotein chains called α (alpha) and β (beta) TCR chains. In contrast, γδ T cells have a TCR that is made up of one γ (gamma) chain and one δ (delta) chain. This group of T cells is usually less common than αβ T cells, but are at their highest abundance in the gut mucosa, within a population of lymphocytes known as intraepithelial lymphocytes (IELs). The antigenic molecules that activate gamma delta T cells are still largely unknown. However, γδ T cells are peculiar in that they do not seem to require antigen processing and major-histocompatibility-complex (MHC) presentation of peptide epitopes, although some recognize MHC class Ib molecules. γδ T cells are believed to have a prominent role in recognition of lipid antigens. They are of an invariant nature and may be triggered by alarm signals, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NKG2D
NKG2D is an activating receptor (transmembrane protein) belonging to the NKG2 family of C-type lectin, C-type lectin-like receptors. NKG2D is encoded by ''KLRK1'' (killer cell lectin like receptor K1) gene which is located in the NK-gene complex (NKC) situated on chromosome 6 in mice and chromosome 12 in humans. In mice, it is expressed by Natural killer cell, NK cells, Natural killer T cell, NK1.1+ T cells, Gamma delta T cell, γδ T cells, activated Cytotoxic T cell, CD8+ αβ T cells and activated macrophages. In humans, it is expressed by Natural killer cell, NK cells, Gamma delta T cell, γδ T cells and Cytotoxic T cell, CD8+ αβ T cells. NKG2D recognizes Induced-self antigen, induced-self proteins from MIC and RAET1/ULBP families which appear on the surface of stressed, malignant transformed, and infected cells. Structure Human NKG2D receptor complex assembles into a hexameric structure. NKG2D itself forms a homodimer whose ectodomains serve for ligand binding. Each NKG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MHC Class I Polypeptide-related Sequence A
MHC may refer to: Biology *Major histocompatibility complex, a highly polymorphic region on chromosome 6 with genes particularly involved in immune functions *Myosin heavy chain, part of the motor protein myosin's quaternary protein structure Colleges * Mars Hill College (now Mars Hill University), a college in Mars Hill, North Carolina, USA * Mount Holyoke College, a college in South Hadley, Massachusetts, USA * William E. Macaulay Honors College, an honors college within the City University of New York Health * Managed health care * Mental health counselor * Metropolitan Hospital Center, East Harlem, New York City Sports * Malaysian Hockey Confederation * Mediterranean Handball Confederation * Mid Hudson Conference * Milwaukee Hurling Club Other * Maimonides Heritage Center * Massachusetts Historical Commission * Mile high club * Mochoʼ language (ISO 639:mhc), a moribund Mayan language spoken in Chiapas, Mexico * Mocopulli Airport (IATA: MHC), Dalcahue, Los Lagos, Chile * Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
