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Collectin
Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca2+-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their function is to bind to oligosaccharide structure or lipids that are on the surface of microorganisms. Like other PRRs they bind pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) of oligosaccharide origin. Binding of collectins to microorganisms may trigger elimination of microorganisms by aggregation, complement activation, opsonization, activation of phagocytosis, or inhibition of microbial growth. Other functions of collectins are modulation of inflammatory, allergic responses, adaptive immune system and clearance of apoptotic cells. Structure Functionally collectins are trimers. Monomeric subunit consists of four parts: * a cysteine-rich domain at the N-terminus * a collagen-like domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collectin Kidney 1
Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca2+-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their function is to bind to oligosaccharide structure or lipids that are on the surface of microorganisms. Like other PRRs they bind pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) of oligosaccharide origin. Binding of collectins to microorganisms may trigger elimination of microorganisms by aggregation, complement activation, opsonization, activation of phagocytosis, or inhibition of microbial growth. Other functions of collectins are modulation of inflammatory, allergic responses, adaptive immune system and clearance of apoptotic cells. Structure Functionally collectins are trimers. Monomeric subunit consists of four parts: * a cysteine-rich domain at the N-terminus * a collagen-like domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collectin Of 46 KDa
Collectin of 46 kDa (CL-46) is a collectin protein. It has two cysteine residues on the N-terminal segment, a hydrophilic loop near the carbohydrate recognition domain's binding site, and a N-glycosylation site in the collagen region. It is expressed in bovine liver and thymus The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. ... glands and binds to pathogens, prompting elimination by macrophages. References Proteins Collectins {{immunology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collectin Liver 1
Collectin-10, also known as collectin liver 1, is a collectin protein that in humans is encoded by the ''COLEC10'' gene. Its structure is similar to mannan-binding lectin ( MBL). Collectin liver 1 (CL-L1) show very similar carbohydrate selectivity as MBL. Two other discovered collectin Collectins (collagen-containing C-type lectins) are a part of the innate immune system. They form a family of collagenous Ca2+-dependent defense lectins, which are found in animals. Collectins are soluble pattern recognition receptors (PRRs). Their ...s include collectin placenta 1 (CL-P1) and collectin kidney 1 (CL-K1). CL-L1's location found to be on chromosome 8 q23-24.1. Research concluded CL-L1 to be a serum protein. References External links * Collectins {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collectin Placenta 1
Collectin-12, also known as collectin subfamily member 12, is a collectin protein that in humans is encoded by the ''COLEC12'' gene. Function This gene encodes a member of the collectin family, proteins that possess collagen-like sequences and carbohydrate recognition domains. This protein is a scavenger receptor that displays several functions associated with host defense. It can bind to carbohydrate antigens on microorganisms, facilitating their recognition and removal. It also mediates the recognition, internalization, and degradation of oxidatively modified low density lipoprotein Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall density ... by vascular endothelial cells. rovided by RefSeq, May 2018 References Further reading * * * * * * * * * {{NLM content ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannan-binding Lectin
Mannose-binding lectin (MBL), also called mannan-binding lectin or mannan-binding protein (MBP), is a lectin that is instrumental in innate immunity as an opsonin and via the lectin pathway. Structure MBL has an oligomeric structure (400-700 kDa), built of subunits that contain three presumably identical peptide chains of about 30 kDa each. Although MBL can form several oligomeric forms, there are indications that dimers and trimers are biologically inactive as an opsonin and at least a tetramer form is needed for activation of complement. Genes and polymorphisms Human MBL2 gene is located on chromosome 10q11.2-q21. Mice have two homologous genes, but in human the first of them was lost. A low level expression of an MBL1 pseudogene 1 (MBL1P1) was detected in liver. The pseudogene encodes a truncated 51-amino acid protein that is homologous to the MBLA isoform in rodents and some primates. Structural mutations in exon 1 of the human MBL2 gene, at codon 52 (Arg to Cys, allele D), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfactant Protein A
Surfactant protein A is an innate immune system collectin. It is water-soluble and has collagen-like domains similar to SP-D. It is part of the innate immune system and is used to opsonize bacterial cells in the alveoli marking them for phagocytosis by alveolar macrophages. SP-A may also play a role in negative feedback limiting the secretion of pulmonary surfactant. SP-A is not required for pulmonary surfactant to function but does confer immune effects to the organism. During parturition The role of surfactant protein A (SP-A) in childbirth is indicated in studies with mice. Mice which gestate for 19 days typically show signs of SP-A in amniotic fluid at around 16 days. If SP-A is injected into the uterus at 15 days, mice typically deliver early. Inversely, an SP-A inhibitor injection causes notable delays in birth. The presence of surfactant protein A seemed to trigger an inflammatory response in the uterus of the mice, but later studies found an anti-inflammatory response in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opsonization
Opsonins are extracellular proteins that, when bound to substances or cells, induce phagocytes to phagocytose the substances or cells with the opsonins bound. Thus, opsonins act as tags to label things in the body that should be phagocytosed (i.e. eaten) by phagocytes (cells that specialise in phagocytosis, i.e. cellular eating). Different types of things ("targets") can be tagged by opsonins for phagocytosis, including: pathogens (such as bacteria), cancer cells, aged cells, dead or dying cells (such as apoptotic cells), excess synapses, or protein aggregates (such as amyloid plaques). Opsonins help clear pathogens, as well as dead, dying and diseased cells. Opsonins were discovered and named "opsonins" in 1904 by Wright and Douglas, who found that incubating bacteria with blood plasma enabled phagocytes to phagocytose (and thereby destroy) the bacteria. They concluded that: “We have here conclusive proof that the blood fluids modify the bacteria in a manner which renders the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglutinin Collectin Of 43 KDa
Conglutinin is a collectin protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo .... External links * Collectins {{Transmembranereceptor-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfactant Protein D
Surfactant protein D, also known as SP-D, is a lung surfactant protein part of the collagenous family of proteins called collectin. In humans, SP-D is encoded by the ''SFTPD'' gene and is part of the innate immune system. Each SP-D subunit is composed of an N-terminal domain, a collagenous region, a nucleating neck region, and a C-terminal lectin domain. Three of these subunits assemble to form a homotrimer, which further assemble into a tetrameric complex. Interactions Surfactant protein D has been shown to interact with DMBT1, and hemagglutinin of influenza A virus. Post-translational modification of SP-D i.e. S-nitrosylation switches its function. See also * pulmonary surfactant Pulmonary surfactant is a surface-active complex of phospholipids and proteins formed by type II alveolar cells. The proteins and lipids that make up the surfactant have both hydrophilic and hydrophobic In chemistry, hydrophobicity is t ... References Further reading * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR2
Toll-like receptor 2 also known as TLR2 is a protein that in humans is encoded by the ''TLR2'' gene. TLR2 has also been designated as CD282 (cluster of differentiation 282). TLR2 is one of the toll-like receptors and plays a role in the immune system. TLR2 is a membrane protein, a receptor, which is expressed on the surface of certain cells and recognizes foreign substances and passes on appropriate signals to the cells of the immune system. Function The protein encoded by this gene is a member of the Toll-like receptor (TLR) family, which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from ''Drosophila'' to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests 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. The process is called phagocytosis, which acts to defend the host against infection and injury. These large phagocytes 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 (adaptive immunity) by recruiting other immune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD14
CD14 (cluster of differentiation 14) is a human protein made mostly by macrophages as part of the innate immune system. It helps to detect bacteria in the body by binding lipopolysaccharide (LPS), a pathogen-associated molecular pattern (PAMP). CD14 exists in two forms, one anchored to the membrane by a glycosylphosphatidylinositol (GPI) tail (mCD14), the other a soluble form (sCD14). Soluble CD14 either appears after shedding of mCD14 (48 kDa) or is directly secreted from intracellular vesicles (56 kDa). The x-ray crystal structure of human CD14 reveals a monomeric, bent solenoid structure containing a hydrophobic amino-terminal pocket. CD14 was the first described pattern recognition receptor. Function CD14 acts as a co-receptor (along with the Toll-like receptor TLR 4 and MD-2) for the detection of bacterial lipopolysaccharide (LPS). CD14 can bind LPS only in the presence of lipopolysaccharide-binding protein (LBP). Although LPS is considered its main ligand, CD14 also rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
