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CD25
The interleukin-2 receptor alpha chain (also called Tac antigen, P55, and mainly CD25) is a protein involved in the assembly of the high-affinity interleukin-2 receptor, consisting of alpha (''IL2RA''), beta ('' IL2RB'') and the common gamma chain (''IL2RG''). As the name indicates, this receptor interacts with interleukin-2, a pleiotropic cytokine which plays an important role in immune homeostasis. Genetics The human protein interleukin-2 receptor subunit alpha is encoded by a gene called ''IL2RA'' with a length around 51,6 kb. Alternative names for this protein coding gene are ''IL2R'', ''IDDM10'' and ''TCGFR''. Location of ''IL2RA'' in human genome is on the short arm of 10th chromosome (10p15.1). Several frequent point mutations, single nucleotide polymorphism (SNP), have been identified in or in close proximity to ''IL2RA'' gene in the population. These SNPs have been linked mainly to susceptibility to immune dysregulation disorders, with majority found in research on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulatory T Cell
The regulatory T cells (Tregs or Treg cells), formerly known as suppressor T cells, are a subpopulation of T cells that modulate the immune system, maintain immune tolerance, tolerance to self-antigens, and prevent autoimmune disease. Treg cells are immunosuppression, immunosuppressive and generally suppress or downregulation and upregulation, downregulate induction and proliferation of effector T cells. Treg cells express the biomarkers CD4, FOXP3, and CD25 and are thought to be derived from the same cell lineage, lineage as naïve T helper cell, CD4+ cells. Because effector T cells also express CD4 and CD25, Treg cells are very difficult to effectively discern from effector CD4+, making them difficult to study. Research has found that the cytokine Transforming growth factor beta, transforming growth factor beta (TGF-β) is essential for Treg cells to differentiate from naïve CD4+ cells and is important in maintaining Treg cell homeostas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin-2
Interleukin-2 (IL-2) is an interleukin, which is a type of cytokine signaling molecule forming part of the immune system. It is a 15.5–16 kDa protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells. Put shortly the function of IL-2 is to stimulate the growth of helper, cytotoxic and regulatory T cells. IL-2 receptor IL-2 is a member of a specific family of cytokines, each member of which has a four alpha helix bundle; this cytokine family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through a IL-2 receptor, a complex consisting of three chains, termed alpha ( CD25), be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymocytes
A thymocyte is an immune cell present in the thymus, before it undergoes transformation into a T cell. Thymocytes are produced as stem cells in the bone marrow and reach the thymus via the blood. Thymopoiesis describes the process which turns thymocytes into mature T cells according to either negative or positive selection. This selection process is vitally important in shaping the population of thymocytes into a peripheral pool of T cells that are able to respond to foreign pathogens but remain tolerant towards the body's own antigens. Positive selection selects cells which are able to bind MHC class I or II molecules with at least a weak affinity. This eliminates (by a process called "death by neglect") those T cells which would be non-functional due to an inability to bind MHC. Negative selection destroys thymocytes with a high affinity for self peptides or MHC. This eliminates cells which would direct immune responses towards self-proteins in the periphery. Negative selection i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin-2 Receptor
The interleukin-2 receptor (IL-2R) is a heterotrimeric protein expressed on the surface of certain immune cells, such as lymphocytes, that binds and responds to a cytokine called IL-2. Composition IL-2 binds to the IL-2 receptor, which has three forms, generated by different combinations of three different proteins, often referred to as "chains": α (alpha) (also called IL-2Rα, CD25, or Tac antigen), β (beta) (also called IL-2Rβ, or CD122), and γ (gamma) (also called IL-2Rγ, γc, common gamma chain, or CD132); these subunits are also parts of receptors for other cytokines. The β and γ chains of the IL-2R are members of the type I cytokine receptor family. Structure-activity relationships of the IL-2/IL-2R interaction The three receptor chains are expressed separately and differently on various cell types and can assemble in different combinations and orders to generate low, intermediate, and high affinity IL-2 receptors. The α chain binds IL-2 with low affi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type 1 Diabetes
Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when the body's immune system destroys pancreatic cells (beta cells). In healthy persons, beta cells produce insulin. Insulin is a hormone required by the body to store and convert blood sugar into energy. T1D results in high blood sugar levels in the body prior to treatment. Common symptoms include frequent urination, increased thirst, increased hunger, weight loss, and other complications. Additional symptoms may include blurry vision, tiredness, and slow wound healing (owing to impaired blood flow). While some cases take longer, symptoms usually appear within weeks or a few months. The cause of type 1 diabetes is not completely understood, but it is believed to involve a combination of genetic and environmental factors. The underlying mechanism involves an autoimmune destruction of the insulin-producing beta cells in the pancreas. Diabetes is diagnosed by testing the leve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL2RB
Interleukin-2 receptor subunit beta is a protein that in humans is encoded by the ''IL2RB'' gene. Also known as CD122; IL15RB; P70-75. Function The interleukin 2 receptor, which is involved in T cell-mediated immune responses, is present in 3 forms with respect to ability to bind interleukin 2. The low affinity form is a monomer of the alpha subunit (also called CD25) and is not involved in signal transduction. The intermediate affinity form consists of a gamma/beta subunit heterodimer, while the high affinity form consists of an alpha/beta/gamma subunit heterotrimer. Both the intermediate and high affinity forms of the receptor are involved in receptor-mediated endocytosis and transduction of mitogenic signals from interleukin 2. The protein encoded by this gene represents the beta subunit and is a type I membrane protein. This protein also forms one of the three subunits of the IL-15 receptor. Activation of the receptor increases proliferation of CD8+ effector T cells. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Helper Cell
The T helper cells (Th cells), also known as CD4+ cells or CD4-positive cells, are a type of T cell that play an important role in the adaptive immune system. They aid the activity of other immune cells by releasing cytokines. They are considered essential in B cell Immunoglobulin class switching, antibody class switching, breaking Cross-presentation, cross-tolerance in dendritic cells, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages and neutrophils. CD4+ cells are mature Th cells that express the surface protein CD4. Genetic variation in regulatory elements expressed by CD4+ cells determines susceptibility to a broad class of autoimmune diseases. Structure and function Th cells contain and release cytokines to aid other immune cells. Cytokines are small protein mediators that alter the behavior of target cells that express Receptor (biochemistry), receptors for those cytokines. These cells help polar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell Receptor
The T-cell receptor (TCR) is a protein complex, located on the surface of T cells (also called T lymphocytes). They are responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. The binding between TCR and antigen peptides is of relatively low affinity and is biologically degenerate (that is, many TCRs recognize the same antigen peptide, and many antigen peptides are recognized by the same TCR). The TCR is composed of two different protein chains (that is, it is a hetero dimer). In humans, in 95% of T cells the TCR consists of an alpha (α) chain and a beta (β) chain (encoded by '' TRA'' and ''TRB'', respectively), whereas in 5% of T cells the TCR consists of gamma and delta (γ/δ) chains (encoded by '' TRG'' and '' TRD'', respectively). This ratio changes during ontogeny and in diseased states (such as leukemia). It also differs between species. Orthologues of the 4 loci have been mapped in various speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic T Cell
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. 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 glycoprotei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendritic Cell
A dendritic cell (DC) is an antigen-presenting cell (also known as an ''accessory cell'') of the mammalian immune system. A DC's main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and adaptive immune systems. Dendritic cells are present in tissues that are in contact with the body's external environment, such as the skin, and the inner lining of the nose, lungs, stomach and intestines. They can also be found in an immature and mature state in the blood. Once activated, they migrate to the lymph nodes, where they interact with T cells and B cells to initiate and shape the adaptive immune response. At certain development stages they grow branched projections, the '' dendrites,'' that give the cell its name (δένδρον or déndron being Greek for 'tree'). While similar in appearance to the dendrites of neurons, these are structures distinct from them. Immature dendr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (; abbreviated MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. This self-protection method can be contrasted with that employed by Natural killer cell, Natural Killer cells. This process of engulfment and digestion is called phagocytosis; it acts to defend the host against infection and injury. Macrophages are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adapti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
