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CXC Chemokine Receptors
CXC chemokine receptors are integral membrane proteins that specifically bind and respond to cytokines of the CXC chemokine family. They represent one subfamily of chemokine receptors, a large family of G protein-linked receptors that are known as seven transmembrane (7-TM) proteins, since they span the cell membrane seven times. There are currently six known CXC chemokine receptors in mammals, named CXCR1 through CXCR6. CXCR1 and CXCR2 CXCR1 and CXCR2 are closely related receptors that recognize CXC chemokines that possess an E-L-R amino acid motif immediately adjacent to their CXC motif. CXCL8 (otherwise known as interleukin-8) and CXCL6 can both bind CXCR1 in humans, while all other ELR-positive chemokines, such as CXCL1 to CXCL7 bind only CXCR2. They are both expressed on the surface of neutrophils in mammals. CXCR3 CXCR3 is expressed predominantly on T cells (T lymphocytes), and also on other lymphocytes B_cell.html" ;"title="ome B cell">ome B cells (B lymphoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL8RA
Interleukin 8 receptor, alpha is a chemokine receptor. This name and the corresponding gene symbol IL8RA have been replaced by the HGNC approved name C-X-C motif chemokine receptor 1 and the approved symbol CXCR1. It has also been designated as CD181 (cluster of differentiation 181). The IUPHAR Committee on Receptor Nomenclature and Drug Classification use the HGNC recommended name, CXCR1. Function The protein encoded by this gene is a member of the G-protein-coupled receptor family. This protein is a receptor for interleukin 8 (IL8). It binds to IL8 with high affinity, and transduces the signal through a G-protein-activated second messenger system. Knockout studies in mice suggested that this protein inhibits embryonic oligodendrocyte precursor migration in developing spinal cord. IL8RA, IL8RB, which encodes another high affinity IL8 receptor, and IL8RBP, a pseudogene of IL8RB, form a gene cluster in a region mapped to chromosome 2q33-q36. Stimulation of CXCR1 in neutrophils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CXCL7
Chemokine (C-X-C motif) ligand 7 (CXCL7) is a human gene. The encoded protein, Chemokine (C-X-C motif) ligand is a small cytokine belonging to the CXC chemokine family. It is an isoform of Beta-Thromboglobulin or ''Pro-Platelet basic protein'' (PPBP). It is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein (in the zymogen form of plasminogen) is en .... References Further reading * * * * * * * * * * * * * * * * * * * * External links * Cytokines {{gene-4-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Langerhans Cells
A Langerhans cell (LC) is a tissue-resident macrophage of the skin once thought to be a resident dendritic cell. These cells contain organelles called Birbeck granules. They are present in all layers of the epidermis and are most prominent in the stratum spinosum. They also occur in the papillary dermis, particularly around blood vessels, as well as in the mucosa of the mouth, foreskin, and vaginal epithelium. They can be found in other tissues, such as lymph nodes, particularly in association with the condition Langerhans cell histiocytosis (LCH). Function In skin infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presenting cells. Generally, tissue-resident macrophages are involved in immune homeostasis and the uptake of apoptotic bodies. However, Langerhans cells can also take on a dendritic cell-like phenotype and migrate to lymph nodes to interact with naive T-cells. Matrix metalloproteinase is important a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendritic Cells
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 dendrit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monocytes
Monocytes are a type of leukocyte or white blood cell. They are the largest type of leukocyte in blood and can differentiate into macrophages and monocyte-derived dendritic cells. As a part of the vertebrate innate immune system monocytes also influence adaptive immune responses and exert tissue repair functions. There are at least three subclasses of monocytes in human blood based on their phenotypic receptors. Structure Monocytes are amoeboid in appearance, and have nongranulated cytoplasm. Thus they are classified as agranulocytes, although they might occasionally display some azurophil granules and/or vacuoles. With a diameter of 15–22 μm, monocytes are the largest cell type in peripheral blood. Monocytes are mononuclear cells and the ellipsoidal nucleus is often lobulated/indented, causing a bean-shaped or kidney-shaped appearance. Monocytes compose 2% to 10% of all leukocytes in the human body. Development Monocytes are produced by the bone marrow from precur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematopoietic
Haematopoiesis (; ; also hematopoiesis in American English, sometimes h(a)emopoiesis) is the formation of blood cellular components. All cellular blood components are derived from haematopoietic stem cells. In a healthy adult human, roughly ten billion () to a hundred billion () new blood cells are produced per day, in order to maintain steady state levels in the peripheral circulation.Semester 4 medical lectures at Uppsala University 2008 by Leif Jansson Process Haematopoietic stem cells (HSCs) Haematopoietic stem cells (HSCs) reside in the medulla of the bone ( bone marrow) and have the unique ability to give rise to all of the different mature blood cell types and tissues. HSCs are self-renewing cells: when they differentiate, at least some of their daughter cells remain as HSCs so the pool of stem cells is not depleted. This phenomenon is called asymmetric division. The other daughters of HSCs ( myeloid and lymphoid progenitor cells) can follow any of the other diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCR5
C-C chemokine receptor type 5, also known as CCR5 or CD195, is a protein on the surface of white blood cells that is involved in the immune system as it acts as a receptor for chemokines. In humans, the ''CCR5'' gene that encodes the CCR5 protein is located on the short (p) arm at position 21 on chromosome 3. Certain populations have inherited the ''Delta 32'' mutation, resulting in the genetic deletion of a portion of the CCR5 gene. Homozygous carriers of this mutation are resistant to infection by macrophage-tropic (M-tropic) strains of HIV-1. Tissue distribution CCR5 is predominantly expressed on T cells, macrophages, dendritic cells, eosinophils, microglia and a subpopulation of either breast or prostate cancer cells. The expression of CCR5 is selectively induced during the cancer transformation process and is not expressed in normal breast or prostate epithelial cells. Approximately 50% of human breast cancer expressed CCR5, primarily in triple negative brea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CXCL12
The stromal cell-derived factor 1 (SDF-1), also known as C-X-C motif chemokine 12 (CXCL12), is a chemokine protein that in humans is encoded by the ''CXCL12'' gene on chromosome 10. It is ubiquitously expressed in many tissues and cell types. Stromal cell-derived factors 1-alpha and 1-beta are small cytokines that belong to the chemokine family, members of which activate leukocytes and are often induced by proinflammatory stimuli such as lipopolysaccharide, TNF, or IL1. The chemokines are characterized by the presence of 4 conserved cysteines that form 2 disulfide bonds. They can be classified into 2 subfamilies. In the CC subfamily, the cysteine residues are adjacent to each other. In the CXC subfamily, they are separated by an intervening amino acid. The SDF1 proteins belong to the latter group. CXCL12 signaling has been observed in several cancers. The ''CXCL12'' gene also contains one of 27 SNPs associated with increased risk of coronary artery disease. Structure Gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CXCL11
C-X-C motif chemokine 11 (CXCL11) is a protein that in humans is encoded by the ''CXCL11'' gene. C-X-C motif chemokine 11 is a small cytokine belonging to the CXC chemokine family that is also called ''Interferon-inducible T-cell alpha chemoattractant'' (I-TAC) and ''Interferon-gamma-inducible protein 9'' (IP-9). It is highly expressed in peripheral blood leukocytes, pancreas and liver, with moderate levels in thymus, spleen and lung and low expression levels were in small intestine, placenta and prostate. Gene expression of CXCL11 is strongly induced by IFN-γ and IFN-β, and weakly induced by IFN-α. This chemokine elicits its effects on its target cells by interacting with the cell surface chemokine receptor CXCR3, with a higher affinity than do the other ligands for this receptor, CXCL9 and CXCL10. CXCL11 is chemotactic for activated T cells. Its gene is located on human chromosome 4 Chromosome 4 is one of the 23 pairs of chromosomes in humans. People normally have two cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CXCL10
C-X-C motif chemokine ligand 10 (CXCL10) also known as Interferon gamma-induced protein 10 (IP-10) or small-inducible cytokine B10 is an 8.7 kDa protein that in humans is encoded by the ''CXCL10'' gene. C-X-C motif chemokine 10 is a small cytokine belonging to the CXC chemokine family. Gene The gene for CXCL10 is located on human chromosome 4 in a cluster among several other CXC chemokines. Function CXCL10 is secreted by several cell types in response to IFN-γ. These cell types include monocytes, endothelial cells and fibroblasts. CXCL10 has been attributed to several roles, such as chemoattraction for monocytes/macrophages, T cells, NK cells, and dendritic cells, promotion of T cell adhesion to endothelial cells, antitumor activity, and inhibition of bone marrow colony formation and angiogenesis. This chemokine elicits its effects by binding to the cell surface chemokine receptor CXCR3. Structure The three-dimensional crystal structure of this chemokine has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CXCL9
Chemokine (C-X-C motif) ligand 9 (CXCL9) is a small cytokine belonging to the CXC chemokine family that is also known as monokine induced by gamma interferon (MIG). The CXCL9 is one of the chemokine which plays role to induce chemotaxis, promote differentiation and multiplication of leukocytes, and cause tissue extravasation. It is closely related to two other CXC chemokines called CXCL10 and CXCL11, whose genes are located near the gene for CXCL9 on human chromosome 4. CXCL9, CXCL10 and CXCL11 all elicit their chemotactic functions by interacting with the chemokine receptor CXCR3. Structre Chemokine (C-X-C motif) ligand 9 (CXCL9) exhibits the classic structure of CXC chemokines, characterized by a short and flexible N-terminal region, a well-ordered core stabilized by two disulfide bonds, three antiparallel beta-strands, and a C-terminal alpha-helix. This conserved tertiary structure provides both stability and the necessary conformational flexibility at the N- and C-termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NK Cells
Natural killer cells, also known as NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. They are a kind of large granular lymphocytes (LGL), and 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 cells, stressed cells, tumor cells, and other intracellular pathogens based on signals from several activating and inhibitory receptors. Most immune cells detect the antigen presented on major histocompatibility complex I (MHC-I) on infected cell surfaces, but NK cells can 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 of the notion that they do not require activation to kill cells that are missing "s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
