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Interleukin-2
Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in 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. IL-2 receptor IL-2 is a member of a cytokine family, each member of which has a four alpha helix bundle; the family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through the IL-2 receptor, a complex consisting of three chains, termed alpha (CD25), beta (CD122) and gamma ( CD132). The gamma chain is shared by all family members. The IL-2 receptor (IL-2R) α subunit binds IL-2 with low affinity (Kd~ 10� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 21
Interleukin 21 (IL-21) is a protein that in humans is encoded by the ''IL21'' gene. Interleukin-21 is a cytokine that has potent regulatory effects on cells of the immune system, including natural killer (NK) cells and cytotoxic T cells that can destroy virally infected or cancerous cells. This cytokine induces cell division/ proliferation in its target cells. Gene The human IL-21 gene is about 8.43kb, mapped to chromosome 4 and 180kb from IL-2 gene, and the mRNA product is 616 nucleotides long. Tissue and cell distribution IL-21 is expressed in activated human CD4+ T cells but not in most other tissues. In addition, IL-21 expression is up-regulated in Th2 and Th17 subsets of T helper cells, as well as T follicular cells. In fact, it was shown that IL-21 can be used to identify peripheral T follicular helper cells. Furthermore, IL-21 is expressed in NK T cells regulating the function of these cells. Interleukin-21 is also produced by Hodgkin's lymphoma (HL) cancer ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin
Interleukins (ILs) are a group of cytokines (secreted proteins and signal molecules) that are expressed and secreted by white blood cells (leukocytes) as well as some other body cells. The human genome encodes more than 50 interleukins and related proteins. The function of the immune system primarily depends on interleukins, and rare deficiencies of a number of them have been described, all featuring autoimmune diseases or immune deficiency. The majority of interleukins are synthesized by CD4 helper T-lymphocyte, as well as through monocytes, macrophages, and endothelial cells. They promote the development and differentiation of T and B lymphocytes, and hematopoietic cells. Interleukin receptors on astrocytes in the hippocampus are also known to be involved in the development of spatial memories in mice. History and name The name "interleukin" was chosen in 1979, to replace the various different names used by different research groups to designate interleukin 1 (lymphocyte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL2RA
Interleukin-2 receptor alpha chain (also called CD25) is the human protein encoded by the ''IL2RA'' gene. The interleukin 2 (IL2) receptor alpha (IL2RA) and beta (IL2RB) chains, together with the common gamma chain (IL2RG), constitute the high-affinity IL2 receptor. Homodimeric alpha chains (IL2RA) result in low-affinity receptor, while homodimeric beta (IL2RB) chains produce a medium-affinity receptor. Normally an integral-membrane protein, soluble IL2RA has been isolated and determined to result from extracellular proteolysis. Alternately-spliced IL2RA mRNAs have been isolated, but the significance of each is currently unknown. Description It is a type I transmembrane protein present on activated T cells, activated B cells, some thymocytes, myeloid precursors, and oligodendrocytes. Though IL2RA has been used as a marker to identify CD4+FoxP3+ regulatory T cells in mice, it has been found that a large proportion of resting memory T cells constitutively express IL2RA in humans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JAK-STAT Signaling Pathway
The JAK-STAT signaling pathway is a chain of interactions between proteins in a cell, and is involved in processes such as immunity, cell division, cell death, and tumour formation. The pathway communicates information from chemical signals outside of a cell to the cell nucleus, resulting in the activation of genes through the process of transcription. There are three key parts of JAK-STAT signalling: Janus kinases (JAKs), signal transducer and activator of transcription proteins (STATs), and receptors (which bind the chemical signals). Disrupted JAK-STAT signalling may lead to a variety of diseases, such as skin conditions, cancers, and disorders affecting the immune system. Structure of JAKs and STATs ''Main articles: JAKs and STATs'' There are four JAK proteins: JAK1, JAK2, JAK3 and TYK2. JAKs contains a FERM domain (approximately 400 residues), an SH2-related domain (approximately 100 residues), a kinase domain (approximately 250 residues) and a pseudokinase domain (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD122
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. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 15
Interleukin-15 (IL-15) is a cytokine with structural similarity to Interleukin-2 (IL-2). Like IL-2, IL-15 binds to and signals through a complex composed of IL-2/IL-15 receptor beta chain (CD122) and the common gamma chain (gamma-C, CD132). IL-15 is secreted by mononuclear phagocytes (and some other cells) following infection by virus(es). This cytokine induces the proliferation of natural killer cells, i.e. cells of the innate immune system whose principal role is to kill virally infected cells. Expression IL-15 was discovered in 1994 by two different laboratories, and characterized as T cell growth factor. Together with Interleukin-2 (IL-2), Interleukin-4 ( IL-4), Interleukin-7 ( IL-7), Interleukin-9 ( IL-9), granulocyte colony-stimulating factor (G-CSF), and granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-15 belongs to the four α-helix bundle family of cytokines. IL-15 is constitutively expressed by a large number of cell types and tissues, including mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL-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 affinit ... [...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. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Gamma Chain
The common gamma chain (γc) (or CD132), also known as interleukin-2 receptor subunit gamma or IL-2RG, is a cytokine receptor sub-unit that is common to the receptor complexes for at least six different interleukin receptors: IL-2, IL-4, IL-7, IL-9, IL-15 and interleukin-21 receptor. The γc glycoprotein is a member of the type I cytokine receptor family expressed on most lymphocyte (white blood cell) populations, and its gene is found on the X-chromosome of mammals. This protein is located on the surface of immature blood-forming cells in bone marrow. One end of the protein resides outside the cell where it binds to cytokines and the other end of the protein resides in the interior of the cell where it transmits signals to the cell's nucleus. The common gamma chain partners with other proteins to direct blood-forming cells to form lymphocytes (a type of white blood cell). The receptor also directs the growth and maturation of lymphocyte subtypes: T cells, B cells, and natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 7
Interleukin 7 (IL-7) is a protein that in humans is encoded by the ''IL7'' gene. IL-7 is a hematopoietic growth factor secreted by stromal cells in the bone marrow and thymus. It is also produced by keratinocytes, dendritic cells, hepatocytes, neurons, and epithelial cells, but is not produced by normal lymphocytes. A study also demonstrate how the autocrine production of the IL-7 cytokine mediated by T-cell acute lymphoblastic leukemia (T-ALL) can be involved in the oncogenic development of T-ALL and offer novel insights into T-ALL spreading. Structure The three-dimensional structure of IL-7 in complex with the ectodomain of IL-7 receptor has been determined using X-ray diffraction. Function Lymphocyte maturation IL-7 stimulates the differentiation of multipotent (pluripotent) hematopoietic stem cells into lymphoid progenitor cells (as opposed to myeloid progenitor cells where differentiation is stimulated by IL-3). It also stimulates proliferation of all cells in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAPK/ERK Pathway
The MAPK/ERK pathway (also known as the Ras-Raf-MEK-ERK pathway) is a chain of proteins in the cell that communicates a signal from a receptor on the surface of the cell to the DNA in the nucleus of the cell. The signal starts when a signaling molecule binds to the receptor on the cell surface and ends when the DNA in the nucleus expresses a protein and produces some change in the cell, such as cell division. The pathway includes many proteins, such as mitogen-activated protein kinases (MAPKs), originally called extracellular signal-regulated kinases (ERKs), which communicate by adding phosphate groups to a neighboring protein ( phosphorylating it), thereby acting as an "on" or "off" switch. When one of the proteins in the pathway is mutated, it can become stuck in the "on" or "off" position, a necessary step in the development of many cancers. In fact, components of the MAPK/ERK pathway were first discovered in cancer cells, and drugs that reverse the "on" or "off" switch are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PI3K/AKT/mTOR Pathway
The PI3K/AKT/mTOR pathway is an intracellular signaling pathway important in regulating the cell cycle. Therefore, it is directly related to cellular quiescence, proliferation, cancer, and longevity. PI3K activation phosphorylates and activates AKT, localizing it in the plasma membrane. AKT can have a number of downstream effects such as activating CREB, inhibiting p27, localizing FOXO in the cytoplasm, activating PtdIns-3ps, and activating mTOR which can affect transcription of p70 or 4EBP1. There are many known factors that enhance the PI3K/AKT pathway including EGF, shh, IGF-1, insulin, and CaM. Both leptin and insulin recruit PI3K signalling for metabolic regulation. The pathway is antagonized by various factors including PTEN, GSK3B, and HB9. In many cancers, this pathway is overactive, thus reducing apoptosis and allowing proliferation. This pathway is necessary, however, to promote growth and proliferation over differentiation of adult stem cells, neural stem cells sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
