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Cd18
In molecular biology, CD18 (Integrin beta chain-2) is an integrin beta chain protein that is encoded by the '' ITGB2'' gene in humans. Upon binding with one of a number of alpha chains, CD18 is capable of forming multiple heterodimers, which play significant roles in cellular adhesion and cell surface signaling, as well as important roles in immune responses. CD18 also exists in soluble, ligand binding forms. Deficiencies in CD18 expression can lead to adhesion defects in circulating white blood cells in humans, reducing the immune system's ability to fight off foreign invaders. Structure and function The ''ITGB2'' protein product is CD18. Integrins are integral cell-surface proteins composed of an alpha chain and a beta chain, and are crucial for cells to be able to efficiently bind to the extracellular matrix. This is especially important for neutrophils, as cellular adhesion plays a large role in extravasation from the blood vessels. A given chain may combine with multiple pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. The presence of integrins allows rapid and flexible responses to events at the cell surface (''e.g''. signal platelets to initiate an interaction with coagulation factors). Several types of integrins exist, and one cell generally has multiple different types on its surface. Integrins are found in all animals while integrin-like receptors are found in plant cells. Integrins work alongside other proteins such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins and syndecans, to mediate cell–cell and cell–matrix interaction. Ligands for integrins include fibronectin, vitronectin, collagen and laminin. Stru ... [...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] |
PSCD1
Cytohesin-1 formerly known as Pleckstrin homology, Sec7 and coiled/coil domains 1 (PSCD1) is a protein that in humans is encoded by the ''CYTH1'' gene. Function Cytohesin-1 (CYTH1) is a member of the cytohesin family. Members of this family have identical structural organization that consists of an N-terminal coiled-coil motif, a central Sec7 domain, and a C-terminal pleckstrin homology (PH) domain. The coiled-coil motif is involved in homodimerization, the Sec7 domain contains guanine-nucleotide exchange protein (GEP) activity, and the PH domain interacts with phospholipids and is responsible for association of CYTHs with membranes. Members of this family appear to mediate the regulation of protein sorting and membrane trafficking. The CYTH1 is highly expressed in natural killer and peripheral T cells, and regulates the adhesiveness of integrins at the plasma membrane of lymphocytes. CYTH1 protein is 83% homologous to CYTH2. Interactions CYTH1 has been shown to interac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNB2L1
Receptor for activated C kinase 1 (RACK1), also known as guanine nucleotide-binding protein subunit beta-2-like 1 (GNB2L1), is a 35 kDa protein that in humans is encoded by the RACK1 gene. Function RACK1 was originally isolated and identified as an intracellular protein receptor for protein kinase C, noting the significant homology to the beta subunit of heterotrimeric G proteins. Later studies established RACK1, and its yeast homolog Asc1, as a core ribosomal protein of the eukaryotic small (40S) ribosomal subunit. Much of the function of Asc1/RACK1 appears to result from its position on the 'head' of the 40S ribosomal subunit. Asc1/RACK1 participates in several aspects of eukaryotic translation and ribosome quality control, including IRES-mediated translation, non-stop decay, non-functional 18S ribosomal RNA decay, and frameshifting. Interactions RACK1 is positioned at the solvent-exposed surface of the 40S ribosomal subunit, where it is held in place through contac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FHL2
Four and a half LIM domains protein 2 also known as FHL-2 is a protein that in humans is encoded by the ''FHL2'' gene. LIM proteins contain a highly conserved double zinc finger motif called the LIM domain. Function FHL-2 is thought to have a role in the assembly of extracellular membranes and may function as a link between presenilin-2 and an intracellular signaling pathway. Family The Four-and-a-half LIM (FHL)-only protein subfamily is one of the members of the LIM-only protein family. Protein members within the group might be originated from a common ancestor and share a high degree of similarity in their amino acid sequence. These proteins are defined by the presence of the four and a half cysteine-rich LIM homeodomain with the half-domain always located in its N-terminus. The name LIM was derived from the first letter of the transcription factors LIN-11, ISL-1 and MEC-3, from which the domain was originally characterized. No direct interactions between LIM domain an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be " miscible in all proportions" (or just "miscible"). The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations,J. de Swaan Arons and G. A. M. Diepen (1966): "Gas—Gas Equilibria". ''Journal of Chemical Physics'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extravasation
Extravasation is the leakage of a fluid out of its contained space into the surrounding area, especially blood or blood cells from vessels. In the case of inflammation, it refers to the movement of white blood cells through the capillary wall, into the surrounding tissues. This is known as leukocyte extravasation, also called diapedesis. In the case of cancer metastasis, it refers to cancer cells exiting the capillaries and entering other tissues, where secondary tumors may form. The term is commonly used in a medical context. More specifically, extravasation can refer to: * Extravasation (intravenous) * Extravasation of infusates * Extravasation of irrigation fluid * Extravasation of urine * Leukocyte extravasation * Angiopellosis (non-leukocyte cell extravastion) Irrigation fluid Extravasation of irrigation fluid is the unintended migration of irrigation fluid (e.g., saline) introduced into a human body. This may occur in several types of endoscopic surgery, such as mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocyte Adhesion Deficiency
Leukocyte adhesion deficiency (LAD) is a rare autosomal recessive disorder characterized by immunodeficiency resulting in recurrent infections. LAD is currently divided into three subtypes: LAD1, LAD2, and the recently described LAD3, also known as LAD-1/variant. In LAD3, the immune defects are supplemented by a Glanzmann thrombasthenia-like bleeding tendency. Signs and symptoms LAD was first recognized as a distinct clinical entity in the 1970s. The classic descriptions of LAD included recurrent bacterial infections, defects in neutrophil adhesion, and a delay in umbilical cord sloughing. The adhesion defects result in poor leukocyte chemotaxis, particularly neutrophil, inability to form pus and neutrophilia. Individuals with LAD suffer from bacterial infections beginning in the neonatal period. Infections such as omphalitis, pneumonia, gingivitis, and peritonitis are common and often life-threatening due to the infant's inability to properly destroy the invading pathogens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagocytosis
Phagocytosis () is the process by which a cell (biology), cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a Multicellular organism, multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. The two main cells that do this are the Macrophages and the Neutrophils of the immune system. Where phagocytosis is used as a means of feeding and provides the organism part or all of its nourishment, it is called phagotrophy and is distinguished from osmotrophy, which is nutrition taking place by absorption. History The history of phag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Innate Immune Response
The innate immune system or nonspecific immune system is one of the two main immunity strategies in vertebrates (the other being the adaptive immune system). The innate immune system is an alternate defense strategy and is the dominant immune system response found in plants, fungi, prokaryotes, and invertebrates (see Beyond vertebrates).. The major functions of the innate immune system are to: * recruit immune cells to infection sites by producing chemical factors, including chemical mediators called cytokines * activate the complement cascade to identify bacteria, activate cells, and promote clearance of antibody complexes or dead cells * identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells * activate the adaptive immune system through antigen presentation * act as a physical and chemical barrier to infectious agents; via physical measures such as skin and mucus, and chemical measures such as clotting factors a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage-1 Antigen
Macrophage-1 antigen (or integrin αMβ2 or macrophage integrin or Mac-1) is a complement receptor ("CR3") consisting of CD11b (integrin αM) and CD18 (integrin β2). The integrin α chain is noncovalently bound to the integrin β chain. It binds to iC3b and can be involved in cellular adhesion, binding to the intercellular adhesion molecule-1 (ICAM-1). CR3 causes phagocytosis and destruction of cells opsonized with iC3b. CR3 and CR4 are thought to exhibit overlapping functions; however, the distinct binding sites to iC3b suggests differences in their functions. Additionally, CR3 has been shown to have therapeutic promise. Function Macrophage-1 antigen (hereafter complement receptor 3 or CR3) (CD11b/CD18) is a human cell surface receptor found on B and T lymphocytes, polymorphonuclear leukocytes (mostly neutrophils), NK cells, and mononuclear phagocytes like macrophages. CR3 is a pattern recognition receptor, capable of recognizing and binding to many molecules found on the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
