A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.
A class of C-type lectins that target the carbohydrate structures found on invading pathogens. Binding of collectins to microorganisms results in their agglutination and enhanced clearance. Collectins form trimers that may assemble into larger oligomers. Each collectin polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen-like region, an alpha-helical coiled-coil region, and carbohydrate-binding region.
Complement activation triggered by the interaction of microbial POLYSACCHARIDES with serum MANNOSE-BINDING LECTIN resulting in the activation of MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. As in the classical pathway, MASPs cleave COMPLEMENT C4 and COMPLEMENT C2 to form C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)
Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
Complement activation initiated by the binding of COMPLEMENT C1 to ANTIGEN-ANTIBODY COMPLEXES at the COMPLEMENT C1Q subunit. This leads to the sequential activation of COMPLEMENT C1R and COMPLEMENT C1S subunits. Activated C1s cleaves COMPLEMENT C4 and COMPLEMENT C2 forming the membrane-bound classical C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
A subclass of lectins that are specific for CARBOHYDRATES that contain MANNOSE.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.
A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
A class of animal lectins that bind specifically to beta-galactoside in a calcium-independent manner. Members of this class are distiguished from other lectins by the presence of a conserved carbohydrate recognition domain. The majority of proteins in this class bind to sugar molecules in a sulfhydryl-dependent manner and are often referred to as S-type lectins, however this property is not required for membership in this class.
Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).
A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
Serum serine proteases which participate in COMPLEMENT ACTIVATION. They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). They cleave COMPLEMENT C4 and COMPLEMENT C2 to form C4b2a, the CLASSICAL PATHWAY C3 CONVERTASE.
A glycine-rich, heat-labile serum glycoprotein that contains a component of the C3 CONVERTASE ALTERNATE PATHWAY (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.
Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.
A component of the CLASSICAL COMPLEMENT PATHWAY. C2 is cleaved by activated COMPLEMENT C1S into COMPLEMENT C2B and COMPLEMENT C2A. C2a, the COOH-terminal fragment containing a SERINE PROTEASE, combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).
Transport proteins that carry specific substances in the blood or across cell membranes.
The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE. It is a constituent of the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb), and COMPLEMENT C5 CONVERTASES in both the classical (C4b2a3b) and the alternative (C3bBb3b) pathway. C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS. It can be inactivated (iC3b) or cleaved by various proteases to yield fragments such as COMPLEMENT C3C; COMPLEMENT C3D; C3e; C3f; and C3g.
The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.
A multifunctional galactin initially discovered as a macrophage antigen that binds to IMMUNOGLOBULIN E, and as 29-35-kDa lectin that binds LAMININ. It is involved in a variety of biological events including interactions with galactose-containing glycoconjugates, cell proliferation, CELL DIFFERENTIATION, and APOPTOSIS.
C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.
Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.
A serum protein which is important in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. This enzyme cleaves the COMPLEMENT C3B-bound COMPLEMENT FACTOR B to form C3bBb which is ALTERNATIVE PATHWAY C3 CONVERTASE.
Serine proteases that cleave COMPLEMENT C3 into COMPLEMENT C3A and COMPLEMENT C3B, or cleave COMPLEMENT C5 into COMPLEMENT C5A and COMPLEMENT C5B. These include the different forms of C3/C5 convertases in the classical and the alternative pathways of COMPLEMENT ACTIVATION. Both cleavages take place at the C-terminal of an ARGININE residue.
A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.
Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b components of complement.
An important soluble regulator of the alternative pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It is a 139-kDa glycoprotein expressed by the liver and secreted into the blood. It binds to COMPLEMENT C3B and makes iC3b (inactivated complement 3b) susceptible to cleavage by COMPLEMENT FACTOR I. Complement factor H also inhibits the association of C3b with COMPLEMENT FACTOR B to form the C3bB proenzyme, and promotes the dissociation of Bb from the C3bBb complex (COMPLEMENT C3 CONVERTASE, ALTERNATIVE PATHWAY).
A product of COMPLEMENT ACTIVATION cascade, regardless of the pathways, that forms transmembrane channels causing disruption of the target CELL MEMBRANE and cell lysis. It is formed by the sequential assembly of terminal complement components (COMPLEMENT C5B; COMPLEMENT C6; COMPLEMENT C7; COMPLEMENT C8; and COMPLEMENT C9) into the target membrane. The resultant C5b-8-poly-C9 is the "membrane attack complex" or MAC.
The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound C4b binds COMPLEMENT C2A, a SERINE PROTEASE, to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).
A 105-kDa serum glycoprotein with significant homology to the other late complement components, C7-C9. It is a polypeptide chain cross-linked by 32 disulfide bonds. C6 is the next complement component to bind to the membrane-bound COMPLEMENT C5B in the assembly of MEMBRANE ATTACK COMPLEX. It is encoded by gene C6.
Endogenous proteins that inhibit or inactivate COMPLEMENT C3B. They include COMPLEMENT FACTOR H and COMPLEMENT FACTOR I (C3b/C4b inactivator). They cleave or promote the cleavage of C3b into inactive fragments, and thus are important in the down-regulation of COMPLEMENT ACTIVATION and its cytolytic sequence.
Enzymes that activate one or more COMPLEMENT PROTEINS in the complement system leading to the formation of the COMPLEMENT MEMBRANE ATTACK COMPLEX, an important response in host defense. They are enzymes in the various COMPLEMENT ACTIVATION pathways.
Compounds that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host.
A screening assay for circulating COMPLEMENT PROTEINS. Diluted SERUM samples are added to antibody-coated ERYTHROCYTES and the percentage of cell lysis is measured. The values are expressed by the so called CH50, in HEMOLYTIC COMPLEMENT units per milliliter, which is the dilution of serum required to lyse 50 percent of the erythrocytes in the assay.
A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.
The smaller fragment generated from the cleavage of complement C3 by C3 CONVERTASE. C3a, a 77-amino acid peptide, is a mediator of local inflammatory process. It induces smooth MUSCLE CONTRACTION, and HISTAMINE RELEASE from MAST CELLS and LEUKOCYTES. C3a is considered an anaphylatoxin along with COMPLEMENT C4A; COMPLEMENT C5A; and COMPLEMENT C5A, DES-ARGININE.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A 206-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c (749-954), and C3dg (955-1303) in the presence COMPLEMENT FACTOR H.
Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.
The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.
Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
A 302-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c, and C3dg (955-1303) in the presence COMPLEMENT FACTOR H. Serum proteases further degrade C3dg into C3d (1002-1303) and C3g (955-1001).
The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.
Molecular sites on or in some B-lymphocytes and macrophages that recognize and combine with COMPLEMENT C3B. The primary structure of these receptors reveal that they contain transmembrane and cytoplasmic domains, with their extracellular portion composed entirely of thirty short consensus repeats each having 60 to 70 amino acids.
Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.
A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).
A plasma serine proteinase that cleaves the alpha-chains of C3b and C4b in the presence of the cofactors COMPLEMENT FACTOR H and C4-binding protein, respectively. It is a 66-kDa glycoprotein that converts C3b to inactivated C3b (iC3b) followed by the release of two fragments, C3c (150-kDa) and C3dg (41-kDa). It was formerly called KAF, C3bINF, or enzyme 3b inactivator.
A serum protein that regulates the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It binds as a cofactor to COMPLEMENT FACTOR I which then hydrolyzes the COMPLEMENT C4B in the CLASSICAL PATHWAY C3 CONVERTASE (C4bC2a).
Phosphoric acid esters of mannose.
A receptor that is specific for IGF-II and mannose-6-phosphate. The receptor is a 250-kDa single chain polypeptide which is unrelated in structure to the type 1 IGF receptor (RECEPTOR, IGF TYPE 1) and does not have a tyrosine kinase domain.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
The smaller fragment formed when complement C4 is cleaved by COMPLEMENT C1S. It is an anaphylatoxin that causes symptoms of immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE) but its activity is weaker than that of COMPLEMENT C3A or COMPLEMENT C5A.
The larger fragment generated from the cleavage of C5 by C5 CONVERTASE that yields COMPLEMENT C5A and C5b (beta chain + alpha' chain, the residual alpha chain, bound by disulfide bond). C5b remains bound to the membrane and initiates the spontaneous assembly of the late complement components to form C5b-8-poly-C9, the MEMBRANE ATTACK COMPLEX.
A serine protease that is the complex of COMPLEMENT C3B and COMPLEMENT FACTOR BB. It cleaves multiple COMPLEMENT C3 into COMPLEMENT C3A (anaphylatoxin) and COMPLEMENT C3B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY.

Mannan binding lectin in febrile adults: no correlation with microbial infection and complement activation. (1/88)

AIMS: To study the role of the mannan binding lectin (MBL) pathway of complement activation in the host defence to microbial infection in vivo, and the role of MBL in infectious mortality in non-selected patients. METHODS: A prospective observational study on 177 hospitalised medical patients with new onset fever. The presence, origin, and microbial cause of infection, the circulating MBL and complement activation product 3a (C3a), and the 28 day hospital course were determined. RESULTS: The patients had median MBL values similar to healthy blood donors: 18% of the patients and 14% of the blood donors had MBL deficiency, with values below 0.1 microg/ml. Median C3a was higher in patients with microbiologically confirmed infection than in those without, whereas there was no difference in MBL values or frequency of deficiency among patient groups with or without positive local cultures or bacteraemia. The mortality rate was 8% and the outcome groups did not differ in MBL. In febrile adults hospitalised in internal medicine wards, microbial infection induces complement activation, independently of MBL. CONCLUSIONS: The results argue against a predominant role for the MBL pathway of complement activation and a deficiency of MBL predisposing to serious and invasive microbial infection in non-selected adults.  (+info)

Human mannose-binding lectin and L-ficolin function as specific pattern recognition proteins in the lectin activation pathway of complement. (2/88)

The innate immune response in vertebrates and invertebrates requires the presence of pattern recognition receptors or proteins that recognize microbial cell components including lipopolysaccharide, bacterial peptidoglycan (PGN), and fungal 1,3-beta-D-glucan. We reported previously that PGN and 1,3-beta-D-glucan recognition proteins from insect hemolymph were able to induce the activation of the prophenoloxidase-activating system, one of the major invertebrate innate immune reactions. The goal of this study was to characterize the biochemical properties and effects of the human counterparts of these molecules. Soluble pattern recognition proteins were purified from human serum and identified as human mannose-binding lectin (MBL) and L-ficolin. The use of specific microbial cell component-coupled columns demonstrated that MBL and L-ficolin bind to PGN and 1,3-beta-D-glucan, respectively. Purified MBL and L-ficolin were associated with MBL-associated serine proteases-1 and -2 (MASPs) and small MBL-associated protein as determined by Western blot analysis. Finally, the binding of purified MBL/MASP and L-ficolin/MASP complexes to PGN and 1,3-beta-D-glucan, respectively, resulted in the activation of the lectin-complement pathway. These results indicate that human PGN and 1,3-beta-D-glucan recognition proteins function as complement-activating lectins.  (+info)

Role of mannose-binding lectin in the innate defense against Candida albicans: enhancement of complement activation, but lack of opsonic function, in phagocytosis by human dendritic cells. (3/88)

Mannose-binding lectin (MBL) is a serum collectin believed to be of importance in innate immunity. We have investigated the role of MBL in the first-line defense against Candida albicans, an opportunistic fungal pathogen. MBL bound C. albicans via its lectin domain, resulting in agglutination of the organisms upon their outgrowth of hyphae. In a human in vitro MBL system, deposition of C4 fragments on C. albicans was increased when exogenous MBL was added to serum samples from MBL-deficient individuals. Similar enhancement of deposition of iC3b also was observed. MBL and enhanced opsonic C3 fragments mediated by MBL did not facilitate opsonophagocytosis of the organisms by monocyte-derived dendritic cells (DCs). However, MBL was found to inhibit the growth of C. albicans independently of complement activation, although, with complement activation, further inhibition was observed. We concluded that MBL plays an important role in the first-line defense against C. albicans without the need for opsonophagocytosis by DCs, in which a direct interaction of MBL with C. albicans results in agglutination and accelerated complement activation via the lectin pathway, leading to inhibition of growth.  (+info)

Role of L-ficolin/mannose-binding lectin-associated serine protease complexes in the opsonophagocytosis of type III group B streptococci. (4/88)

Serotype III group B streptococci (GBS) are a common cause of neonatal sepsis and meningitis. Although deficiency in maternal capsular polysaccharide (CPS)-specific IgG correlates with susceptibility of neonates to the GBS infection, serum deficient in CPS-specific IgG mediates significant opsonophagocytosis. This IgG-independent opsonophagocytosis requires activation of the complement pathway, a process requiring the presence of both Ca(2+) and Mg(2+), and is significantly reduced by chelating Ca(2+) with EGTA. In these studies, we defined a role of L-ficolin/mannose-binding lectin-associated serine protease (MASP) complexes in Ca(2+)-dependent, Ab-independent opsonophagocytosis of serotype III GBS. Incubation of GBS with affinity-purified L-ficolin/MASP complexes and C1q-depleted serum deficient in CPS-specific Ab supported opsonophagocytic killing, and this killing was inhibited by fluid-phase N-acetylglucosamine, the ligand for L-ficolin. Binding of L-ficolin was proportional to the CPS content of individual strains, and opsonophagocytic killing and C4 activation were inhibited by fluid-phase CPS, suggesting that L-ficolin binds to CPS. Sialic acid is known to inhibit alternative complement pathway activation, and, as expected, the bactericidal index (percentage of bacteria killed) for individual strains was inversely proportional to the sialic acid content of the CPS, and L-ficolin-initiated opsonophagocytic killing was significantly increased by addition of CPS-specific IgG2, which increased activation of the alternative pathway. We conclude that binding of L-ficolin/MASP complexes to the CPS generates C3 convertase C4b2a, which deposits C3b on GBS. C3b deposited by this lectin pathway forms alternative pathway C3 convertase C3bBb whose activity is enhanced by CPS-specific IgG2, leading to increased opsonophagocytic killing by further deposition of C3b on the GBS.  (+info)

Deficiency of the mannan-binding lectin pathway of complement and poor outcome in cystic fibrosis: bacterial colonization may be decisive for a relationship. (5/88)

In cystic fibrosis (CF) prognosis concerning lung damage development is highly variable and difficult to predict. Mannan-binding lectin (MBL) deficiency has been reported to be associated with poor outcome in CF lung disease. MBL is a recognition molecule of the MBL pathway of the complement system and is encoded by a gene characterized by a high degree of polymorphism. Some genotypes result in low serum concentrations of MBL. MBL-associated serine protease 2 (MASP-2) is another protein belonging to the MBL pathway. A mutation resulting in low levels of MASP-2 in serum has been described recently. In the present study, 112 CF patients aged 4-54 years were investigated for MBL and MASP-2 genotypes, serum levels of MBL and MASP-2 and the MBL pathway function in serum. No correlation to reduced lung function or need for lung transplantation was seen, either for MBL deficiency, MASP-2 gene mutation or reduced MBL pathway function. However, in the 27 patients colonized with Staphylococcus aureus, MBL-deficient genotypes were associated with decreased lung function. As expected, MBL pathway function in serum was reduced both in MBL-deficient patients and in patients carrying a mutant MASP-2 allele. An unexpected finding was that CF patients had higher serum levels of MBL than healthy controls when corrected for MBL genotype. In conclusion, MBL pathway function was affected both by MBL and by MASP-2 genotypes. However, MBL or MASP-2 levels in serum did not affect the clinical outcome in the cohort of CF patients studied.  (+info)

Composition of the lectin pathway of complement in Gallus gallus: absence of mannan-binding lectin-associated serine protease-1 in birds. (6/88)

The lectin pathway of complement is activated by multimolecular complexes that recognize and bind to microbial polysaccharides. These complexes comprise a multimeric carbohydrate recognition subunit (either mannan-binding lectin (MBL) or a ficolin), three MBL-associated serine proteases (MASP-1, -2, and -3), and MAp19 (a truncated product of the MASP-2 gene). In this study we report the cloning of chicken MASP-2, MASP-3, and MAp19 and the organization of their genes and those for chicken MBL and a novel ficolin. Mammals usually possess two MBL genes and two or three ficolin genes, but chickens have only one of each, both of which represent the undiversified ancestors of the mammalian genes. The primary structure of chicken MASP-2 is 54% identical with those of the human and mouse MASP-2, and the organization of its gene is the same as in mammals. MASP-3 is even more conserved; chicken MASP-3 shares approximately 75% of its residues with human and Xenopus MASP-3. It is more widely expressed than other lectin pathway components, suggesting a possible function of MASP-3 different from those of the other components. In mammals, MASP-1 and MASP-3 are alternatively spliced products of a single structural gene. We demonstrate the absence of MASP-1 in birds, possibly caused by the loss of MASP-1-specific exons during phylogeny. Despite the lack of MASP-1-like enzymatic activity in sera of chicken and other birds, avian lectin pathway complexes efficiently activate C4.  (+info)

Gastrointestinal ischemia-reperfusion injury is lectin complement pathway dependent without involving C1q. (7/88)

Complement activation plays an important role in local and remote tissue injury associated with gastrointestinal ischemia-reperfusion (GI/R). The role of the classical and lectin complement pathways in GI/R injury was evaluated using C1q-deficient (C1q KO), MBL-A/C-deficient (MBL-null), complement factor 2- and factor B-deficient (C2/fB KO), and wild-type (WT) mice. Gastrointestinal ischemia (20 min), followed by 3-h reperfusion, induced intestinal and lung injury in C1q KO and WT mice, but not in C2/fB KO mice. Addition of human C2 to C2/fB KO mice significantly restored GI/R injury, demonstrating that GI/R injury is mediated via the lectin and/or classical pathway. Tissue C3 deposition in C1q KO and WT, but not C2/fB KO, mice after GI/R demonstrated that complement was activated in C1q KO mice. GI/R significantly increased serum alanine aminotransferase, gastrointestinal barrier dysfunction, and neutrophil infiltration into the lung and gut in C1q KO and WT, but not C2/fB KO, mice. MBL-null mice displayed little gut injury after GI/R, but lung injury was present. Addition of recombinant human MBL (rhuMBL) to MBL-null mice significantly increased injury compared with MBL-null mice after GI/R and was reversed by anti-MBL mAb treatment. However, MBL-null mice were not protected from secondary lung injury after GI/R. These data demonstrate that C2 and MBL, but not C1q, are necessary for gut injury after GI/R. Lung injury in mice after GI/R is MBL and C1q independent, but C2 dependent, suggesting a potential role for ficolins in this model.  (+info)

Mannose-binding lectin is a regulator of inflammation that accompanies myocardial ischemia and reperfusion injury. (8/88)

The mannose-binding lectin (MBL), a circulating pattern recognition molecule, recognizes a wide range of infectious agents with resultant initiation of the complement cascade in an Ab-independent manner. MBL recognizes infectious non-self and altered self in the guise of apoptotic and necrotic cells. In this study, we demonstrate that mice lacking MBL, and hence are devoid of MBL-dependent lectin pathway activation but have fully active alternative and classical complement pathways, are protected from cardiac reperfusion injury with resultant preservation of cardiac function. Significantly, mice that lack a major component of the classical complement pathway initiation complex (C1q) but have an intact MBL complement pathway, are not protected from injury. These results suggest that the MBL-dependent pathway of complement activation is a key regulator of myocardial reperfusion ischemic injury. MBL is an example of a pattern recognition molecule that plays a dual role in modifying inflammatory responses to sterile and infectious injury.  (+info)

Rooryck C, Diaz-Font A, Osborn DP, Chabchoub E, Hernandez-Hernandez V, Shamseldin H, Kenny J, Waters A, Jenkins D, Kaissi AA, Leal GF, Dallapiccola B, Carnevale F, Bitner-Glindzicz M, Lees M, Hennekam R, Stanier P, Burns AJ, Peeters H, Alkuraya FS, Beales PL. Mutations in lectin complement pathway genes COLEC11 and MASP1 cause 3MC syndrome. Nat Genet. 2011 Mar;43(3):197-203.. ...
(lek tin) The lectin pathway for complement activation is triggered by the binding of a serum lectin (mannan binding lectin; MBL) to mannose containing proteins or to carbohydrates on viruses or bacteria
The complement system plays a key role in host defense against pneumococcal infection. Three different pathways, the classical, alternative and lectin pathways, mediate complement activation. While there is limited information available on the roles of the classical and the alternative activation pathways of complement in fighting streptococcal infection, little is known about the role of the lectin pathway, mainly due to the lack of appropriate experimental models of lectin pathway deficiency. We have recently established a mouse strain deficient of the lectin pathway effector enzyme mannan-binding lectin associated serine protease-2 (MASP-2) and shown that this mouse strain is unable to form the lectin pathway specific C3 and C5 convertases. Here we report that MASP-2 deficient mice (which can still activate complement via the classical pathway and the alternative pathway) are highly susceptible to pneumococcal infection and fail to opsonize Streptococcus pneumoniae in the none-immune host. ...
Principal Investigator:MATSUSHITA Misao, Project Period (FY):1996 - 1997, Research Category:Grant-in-Aid for Scientific Research (C), Section:一般, Research Field:Immunology
Microbial infection urges prompt intervention by the immune system. The complement cascade and neutrophil granulocytes are the predominant contributors to this immediate anti-microbial action. We have previously shown that mannan-binding lectin-associated serine protease-1 (MASP-1), the most abundant enzyme of the complement lectin pathway, can induce p38-MAPK activation, NFkappaB signaling, and Ca2+-mobilization in endothelial cells. Since neutrophil chemotaxis and transmigration depends on endothelial cell activation, we aimed to explore whether recombinant MASP-1 (rMASP-1) is able to induce cytokine production and subsequent neutrophil chemotaxis in human umbilical vein endothelial cells (HUVEC). We found that HUVECs activated by rMASP-1 secreted IL-6 and IL-8, but not IL-1alpha, IL-1ra, TNFalpha and MCP-1. rMASP-1 induced dose-dependent IL-6 and IL-8 production with different kinetics. rMASP-1 triggered IL-6 and IL-8 production was regulated predominantly by the p38-MAPK pathway. Moreover, the
BioMed Research International is a peer-reviewed, Open Access journal that publishes original research articles, review articles, and clinical studies covering a wide range of subjects in life sciences and medicine. The journal is divided into 55 subject areas.
Omeros Corporation is a biopharmaceutical company engaged in discovering, developing and commercializing small-molecule and protein therapeutics for market, as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system. The Companys marketed drug product, Omidria (phenylephrine and ketorolac injection), is used during cataract surgery or intraocular lens replacement. Its clinical programs include Mannan-binding lectin-associated serine protease-2 (MASP-2) (OMS721)-Lectin Pathway Disorders; PDE10 (OMS824)-CNS Disorders; peroxisome proliferator-activated receptor gamma (PPARy) (OMS405)-Addiction, and OMS201-Urology. Its preclinical programs include phosphodiesterase 7 (PDE7) (OMS527), Plasmin (OMS616), MASP-3 (OMS906)-Alternative Pathway Disorders, GPR17-CNS Disorders, GPR101-Metabolic Disorders, GPR151-CNS Disorders, GPR161-Cancer, GPR174-Immune Disorders, GPR183-Skeletal and Infectious Diseases, GPCR Platform and Antibody Platform.. ...
FDA granted Omeros lead human monoclonal antibody (mAb) OMS721 breakthrough therapy designation for the treatment of immunoglobulin A (IgA) nephropathy. The antibody targets mannan-binding lectin-associated serine protease-1 (MASP-2). Omeros holds global rights to MASP-2 and therapeutics targeting the lectin pathway effector enzyme.
Tytu : Mannan-binding lectin-associated serine protease-2 (MASP-2) in a large cohort of neonates and its clinical associations. ...
The complement system constitutes a critical component of the innate immune response. The lectin pathway is one of the three activation pathways of the complement activation cascade that can recognise and respond to structures on oxygen deprived cells and contribute to ischaemia and reperfusion injury (IRI). Cerebral IRI mediated inflammation is known to be responsible for secondary damage in the penumbra region surrounding the initial area of infarct and the prevention of IRI-mediated secondary damage provides an attractive target for therapeutic intervention. Mannose binding lectin associated serine protease 2 (MASP-2) is the key effector enzyme of the lectin pathway, since depletion of this enzyme completely ablates lectin pathway function or activity. This study assessed the impact of MASP-2 deficiency on cerebral IRI and to what extent MASP-2 targeting can reduce the secondary inflammatory damage following an ischaemic insult. The 3 vessel occlusion (3-VO) model of stroke was found to be ...
Background and Aim: Mannose binding-lectin (MBL) is an important component of innate immunity, and activator of the lectin complement pathway. Within the MBL2 gene are seven secretor haplotypes that code for altered serum MBL levels and complement activation. As complement is important in the pathophysiology of myocardial injury, we determined if MBL2 secretor haplotypes are independently associated with an increased risk of in-hospital, postoperative MI in patients undergoing CABG surgery.. Methods: Prospective, longitudinal multi-institutional study of 978 patients undergoing primary, elective CABG-only surgery with cardiopulmonary bypass between 8/2001 and 5/2005. Genotyping of 18 polymorphic sites within the MBL2 gene was performed at the National Cancer Institute using Sequenom MALDI-TOF. Multivariate, stepwise logistic regression was performed controlling for patient demographics, preoperative risk factors, medications and intraoperative variables to determine if MBL2 secretor haplotypes ...
1Q3X: The structure of MBL-associated serine protease-2 reveals that identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions
Ficolins are a group of proteins mainly consisting of collagen-like and fibrinogen-like domains and are thought to play a role in innate immunity via their carbohydrate-binding activities. Two types of ficolins have been identified in mice, ficolin A, and ficolin B. However, their structure and func …
My daughter was just diagnosed with a MBL (mannose-binding lectin) deficiency. She is 6 years old now and has been plagued by multiple pneumonias and sinus infections. What is the prognosis of this def...
MBL : Evaluation of children and adults with a clinical history of recurrent infections Results may be useful for genetic counseling and support aggressive management of recurrent infections in patients with reduced levels of mannose-binding lectin
Sigma-Aldrich offers abstracts and full-text articles by [Michael Osthoff, Melinda M Dean, Paul N Baird, Andrea J Richardson, Mark Daniell, Robyn H Guymer, Damon P Eisen].
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
Reactome is pathway database which provides intuitive bioinformatics tools for the visualisation, interpretation and analysis of pathway knowledge.
摘要 利用Bac-to-Bac昆虫杆状病毒表达系统表达具有天然构象的猪Ficolin α。首先构建重组穿梭质粒rBacmid-Ficolin α,转染sf9细胞获得重组杆状病毒rBV-Ficolin α;通过Image J软件对优化表达的Western blot图片进行灰度分析确定较佳表达条件;纯化目的蛋白质后,进一步评价其体外抗病毒活性。Western blot结果显示以7.5 MOI接种量感染的sf9细胞在96 h时获得了较高的表达,同时获得的重组猪Ficolin α具有抗猪繁殖与呼吸综合征病毒(PRRSV)活性。猪Ficolin α在sf9昆虫细胞中获得成功表达,且具有良好的抗PRRSV活性。本研究可以为猪Ficolin α的抗病毒活性及作用机制研究提供物质基础。. ...
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Hi, a little bit of background - 27 yr. old female. Drink once a week and ex-smoker. Medications currently taking Multi-vitamin w/ numerous supplements, Nasonex, Xananx on occassion, Allegra-D on occa...
MBL forms oligomers of subunits, which are trimers (6- to 18-heades correspond to a dimer and a hexamer, respectively). Multimers of MBL form a complex with MASP1 (Mannose-binding lectin-Associated Serine Protease), MASP2 and MASP3, that are protease zymogens. The MASPs are very similar to C1r and C1s molecules of the classical complement pathway, respectively, and are thought to have a common evolutionary ancestor. When the carbohydrate-recognising heads of MBL bind to specifically arranged mannose residues on the surface of a pathogen, MASP-1 and MASP-2 are activated to cleave complement components C4 and C2 into C4a, C4b, C2a, and C2b. In addition, two smaller MBL-associated proteins (MAps) are found in complex with MBL. MBL-associated protein of 19 kDa (MAp19) and MBL-associated protein of 44 kDa (Map44). MASP-1, MASP-3 and MAp44 are alternative splice products of the MASP1 gene, while MASP-2 and MAp19 are alternative splice products of the MASP-2 gene. MAp44 has been suggested to act as a ...
Jenny, Lorenz and Dobó, József and Gál, Péter and Pál, Gábor and Lam, Wilbur A. and Schroeder, Verena (2018) MASP-1 of the complement system enhances clot formation in a microvascular whole blood flow model. PLOS ONE, 13 (1). pp. 1-14. ISSN 1932-6203 Oroszlán, Gábor and Dani, Ráhel and Szilágyi, András and Závodszky, Péter and Thiel, Steffen and Gál, Péter and Dobó, József (2017) Extensive Basal Level Activation of Complement Mannose-Binding Lectin-Associated Serine Protease-3: Kinetic Modeling of Lectin Pathway Activation Provides Possible Mechanism. FRONTIERS IN IMMUNOLOGY, 8. pp. 1-14. ISSN 1664-3224 Tóbiás, Zoltán and Pálinkó, Dóra and Sztanó, Balázs and Csanády, Miklós and Gál, Péter and Rovó, László (2017) A laryngomalacia endoszkópos ultrapulzációs-lézeres (ultra dream pulse) sebészete. A módszer hazai bevezetése során szerzett tapasztalataink , Endoscopic ultra dream pulse laser surgery of laryngomalacia. Our experiences gained during the ...
The complement system is a group of immune system proteins that work together to destroy foreign invaders (pathogens), trigger inflammation, and remove debris from cells and tissues. Mannose-binding lectin can also stimulate special immune cells to engulf and break down the attached pathogen.. Mutations in the MBL2 gene can reduce the production of the mannose-binding lectin subunit or eliminate the subunits ability to assemble into functional mannose-binding lectin. A decrease in the availability of the normal subunit protein may lead to a reduction of the functional mannose-binding lectin in blood. With decreased levels of mannose-binding lectin, the body does not recognize and fight foreign invaders efficiently. Consequently, infections can be more common in people with this condition.. However, not everyone with a change in the MBL2 gene has decreased levels of mannose-binding lectin, and not everyone with decreased protein levels is prone to infection. Researchers believe that a number of ...
Several common mutations of the MBL2 gene can lead to a condition called mannose-binding lectin deficiency. People with this condition have low levels of mannose-binding lectin and may be susceptible to recurrent infections. Several of the disease-associated mutations occur in a region of the MBL2 gene known as exon 1 and result in a change to single protein building blocks (amino acids) in the mannose-binding lectin subunit. Other mutations occur in an area of DNA near the MBL2 gene called the promoter region, which helps control the production of the mannose-binding lectin subunit.. The change of a single amino acid in the mannose-binding lectin subunit eliminates its ability to assemble into the functional mannose-binding lectin. Similarly, certain mutations in the promoter region of the MBL2 gene reduce production of the mannose-binding lectin subunit, leading to a decreased number of subunits available for protein assembly and a reduction in the amount of functional protein. With decreased ...
Mannose-binding lectin (MBL) mediates the innate immune response either through direct opsonisation of microorganisms or through activation of the complement system. There are conflicting data whether MBL deficiency leads to increased susceptibility to infections or not. The aim of this study was to determine if low levels of mannose-binding lectin (MBL) predict sepsis development, sepsis severity and outcome from severe sepsis or septic shock. Patients aged 18 years or more with documented sepsis within 24 h after admission to the intensive care unit were included if they had participated in a health survey and donated blood samples prior to the sepsis event. A subset of these patients had stored plasma also from the acute phase. Two matched referents free of known sepsis were selected for each case. Plasma levels MBL were determined in stored samples from health surveys (baseline) and from ICU admission (acute phase). The association between MBL and sepsis, sepsis severity and in-hospital mortality
Mannose-binding lectin (MBL), a serum protein belonging to the collectin family, is considered to be a pattern recognition molecule designed to detect pathogen-associated molecular patterns (5). MBL exists in serum as multimeric trimers of 32-kDa polypeptide chains; each chain has a carbohydrate recognition domain (CRD) and a collagen-like region for trimeric assembly. The CRD has been shown to bind mannose, fucose, and N-acetylglucosamine (4), and the cluster of CRDs rendered by oligomerization is thought to be suitable for binding polymeric sugars found on microbes (19, 42). Indeed, MBL has been shown to bind a host of pathogens, including subsets of gram-positive and gram-negative bacteria, Mycobacterium tuberculosis, and Candida albicans (5, 31). Once bound to microbes, MBL is believed to act as an opsonin for phagocytosis (17) and to activate the complement cascade via mannose-binding lectin-associated protein 2 (MASP-2) for microbial lysis (28, 34, 39).. MBL is encoded by a single gene in ...
The high degree of parallelism in complement activation hinders a better understanding of the individual roles and relative importance of the three activation pathways both in physiological as well as in pathological processes. Specific inhibitors are extremely useful tools for basic research and therapeutic purposes. Previously, there were attempts to develop pathway-selective inhibitors by preventing the binding of the recognition molecules (C1q and MBL) to their targets (50, 51). Each activation pathway is associated with unique proteases, which could be appropriate targets for such inhibitors. Although SPs are among the most druggable targets of the complement system, early drug development efforts failed to yield specific complement inhibitors (21).. There are several X-ray structures of complement initiator proteases, but none of these present the protease in complex with an interacting peptide substrate or inhibitor (38-40, 52, 53). Without such a binding partner, the functional binding ...
Functional mannose-binding lectin (f-MBL) plays an important role in the innate neonatal immune system. We studied the origin of f-MBL in umbilical cord blood (UCB) by measuring maternal MBL (n=47), collected before elective cesarean section, and neo
Blotting, Western; Calcium; Cells, Cultured; Complement Activation; Complement Pathway, Mannose-Binding Lectin; Human Umbilical Vein Endothelial Cells; Humans; Immunity, Innate; Mannose-Binding Lectin; Mannose-Binding Protein-Associated Serine Proteases; Microscopy, Fluorescence; Mutation; Peptide Fragments; Protein Binding; Proteolysis; Recombinant Proteins ...
Purified Recombinant Human MBL2 Protein, MYC/DDK-tagged from Creative Biomart. Recombinant Human MBL2 Protein, MYC/DDK-tagged can be used for research.
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Innate immunity relies upon the ability of a variety of recognition molecules to sense pathogens through conserved molecular signatures that are often carbohydrates. Ficolins are oligomeric proteins assembled from collagen-like stalks and fibrinogen-
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Hi Everyone, Three weeks ago, I found out from Gareths Immunologist that he has MBL deficiency --- Mannose-binding Lectin deficiency. From what I have b...
Low lectin foods - what can a very low level of mannose-binding lectin mean and how can it be treated? a rare. deficiency to affect someone clinically,
MBL-C antibody [4J25] (mannose-binding lectin (protein C) 2, soluble) for Neut, WB. Anti-MBL-C mAb (GTX52919) is tested in Human samples. 100% Ab-Assurance.
MBL-C antibody, C-term (mannose-binding lectin (protein C) 2, soluble) for WB. Anti-MBL-C pAb (GTX89586) is tested in Human samples. 100% Ab-Assurance.
Ficolin-3 Isoform 2 products available through Novus Biologicals. Browse our Ficolin-3 Isoform 2 product catalog backed by our Guarantee+.
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Individuals with low levels of mannan-binding lectin (MBL) appear to be susceptible to infectious diseases. This suggests that substitution therapy with MBL might be a beneficial treatment of patients with MBL deficiency. A production process for an MBL product has been developed from a fraction II+III precipitate obtained by ethanol fractionation of plasma. The MBL process includes three chromatographic steps, where the first and key step is affinity chromatography on a cross-linked agarose matrix selecting for oligomeric, carbohydrate-binding MBL. The yield from the production process is about 25% of the plasma MBL content, and the purity is about 65%. The MBL product shows mannan-binding activity and complement-activating ability. A safety study has shown this plasma-derived MBL to be safe and well tolerated in adult MBL-deficient volunteers. ...
Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards C. parapsilosis in vitro. High avidity binding was observed between MBL and C. albicans and C. parapsilosis. Addition of MBL to MBL deficient serum increased the deposition of C4 and C3b and enhanced the uptake of C. albicans, C. parapsilosis and acapsular C. neoformans by polymorphonuclear cells (PMNs). Compared to other microorganisms, such as Escherichia coli, Staphylococcus aureus and Cryptococcus neoformans, C. parapsilosis and Candida albicans were potent activators of the lectin pathway. Our results suggest that MBL plays a crucial role in the innate immunity against infections caused by yeast
This gene encodes a serine protease that functions as a component of the lectin pathway of complement activation. The complement pathway plays an essential role in the innate and adaptive immune response. The encoded protein is synthesized as a zymogen and is activated when it complexes with the pathogen recognition molecules of lectin pathway, the mannose-binding lectin and the ficolins. This protein is not directly involved in complement activation but may play a role as an amplifier of complement activation by cleaving complement C2 or by activating another complement serine protease, MASP-2. The encoded protein is also able to cleave fibrinogen and factor XIII and may may be involved in coagulation. A splice variant of this gene which lacks the serine protease domain functions as an inhibitor of the complement pathway. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Apr 2010 ...
Mannan Binding Lectin (MBL) is a member of the lectin pathway of the complement system and plays an important role in the innate immune system. MBL replacement in MBL-deficient children with chemotherapy-induced neutropenia represents a new approach to lower the risk of febrile episodes, of hospital admission, of prolonged use of intravenous antibiotics and of severe infections.. The aim of the Phase II study is to find evidence for the correct prediction of plasma levels of MBL necessary for clinical effects and biological efficacy, to confirm the dosage regimen needed to reach the required MBL plasma levels, and reconfirm the safety and lack of side-effects. ...
Mannose binding lectin (MBL) is a calcium-dependent lectin that plays an important role innate immunity by activating the complement pathway. There have been a number of studies describing an association between the MBL genotype and disease susceptibility. ...
Research abstract: Chronic fatigue syndrome (CFS) is a severe disease characterized by various symptoms of immune dysfunction. CFS onset is typically with an infection and many patients suffer from frequently recurrent viral or bacterial infections. Immunoglobulin and mannose binding lectin … Continue reading →. ...
Mannan-Binding lectin (MBL) is a serum lectin and an important constituent of the innate immune system. Processes linked to the innate immune response have previously been implicated in Alzheimers disease (AD). MBL is associated with blood vessels in the brain and AD patients demonstrate lower MBL levels in the cerebrospinal fluid compared to controls. We investigated six single nucleotide polymorphisms, linked to MBL deficiency, in the corresponding MBL2 gene in AD patients and controls. Two MBL2 haplotypes, LXP and LYQ, were significantly associated with AD risk (OR = 1.6, p = 0.01 and OR = 1.5, p = 0.02, respectively). The present study is the first investigating MBL2 genotypes and haplotypes in relation to AD. Our findings support that the MBL2 gene impact the disease risk.
This unit contains protocols that can be used to measure mannan‐binding lectin (MBL) levels and MBL pathway activity in human plasma or serum
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Background: Mannose-binding lectin is a collectin involved in host defense against infection. Whether mannose-binding lectin deficiency is associated with acute exacerbations of chronic obstructive pulmonary disease is debated. Methods: Participants in a ...
A komplement rendszer aktiválódásának lektin útja az egyik első védelmi vonalnak tekinthető a szervezet fertőzések elleni védekezésében. A mannóz kötő lektin (MBL) baktérium felszínhez való kötődése után szerin proteáz zimogének (MASP= MBL-kötött szerin proteáz) aktiválódnak, melyek többféle mechanizmus révén járulnak hozzá az idegen mikroorganizmus megsemmisítéséhez ill. eltávolításához. Munkánk során felderítettük, a proteolitikus kaszkádrendszer beindításáért felelős MASP-2 enzim autoaktiválódásásnak mechanizmusát atomi szinten. Felfedeztük a MASP-2 egy eddig ismeretlen biológiai funkcióját, amely kapcsolatot teremt a véralvadási és a komplement kaszkád között. A MASP-2 hasítja és aktiválja a protrombint. Ugyancsak részletesen tanulmányoztuk a MASP-1 trombin-szerű aktivitását is. Ezek az eredmények arra utalnak, hogy a vérben lévő két proteolitikus kaszkádrendszer szoros evolúciós és funkcionális ...
pep:known chromosome:VEGA66:18:65980754:66002637:-1 gene:OTTMUSG00000030654 transcript:OTTMUST00000075892 gene_biotype:protein_coding transcript_biotype:protein_coding gene_symbol:Lman1 description:lectin, mannose-binding, 1 ...
... hence preventing cleavage of C4 and C2 mannan-binding lectin lectin pathway Degn SE, Hansen AG, Steffensen R, Jacobsen C, ... Mannose-binding lectin-associated protein of 44 kDa (MAp44) is a protein arising from the human MASP1 gene. MASP-1, MASP-3 and ... protein associated with pattern recognition molecules of the complement system and regulating the lectin pathway of complement ... MAp44 has been suggested to act as a competitive inhibitor of lectin pathway activation, by displacing MASP-2 from MBL, ...
Lectin pathway. The lectin pathway is homologous to the classical pathway, but with the opsonin, mannose-binding lectin (MBL), ... Three biochemical pathways activate the complement system: the classical complement pathway, the alternative complement pathway ... The mannose-binding lectin pathway can be activated by C3 hydrolysis or antigens without the presence of antibodies (non- ... Alternative pathwayEdit. Main article: Alternative complement pathway. The alternative pathway is continuously activated at a ...
... the classical complement pathway, the alternate complement pathway, and the mannose-binding lectin pathway. The classical ... Complement system[edit]. Main article: Complement system. The complement system is a biochemical cascade of the innate immune ... 12 of which are directly involved in the complement pathways.[1] The complement system is involved in the activities of both ... The B cell waits for the TH cell to bind to the complex. This binding will activate TH cell and it releases cytokines that ...
Once bound to the ligands MBL and Ficolin oligomers recruit MASP1 and MASP2 and initiate the lectin pathway of complement ... Dommett RM, Klein N, Turner MW (September 2006). "Mannose-binding lectin in innate immunity: past, present and future". Tissue ... One very important collectin is mannan-binding lectin (MBL), a major PRR of the innate immune system that binds to a wide range ... Membrane-bound PRRs include Toll like receptors (TLRs) and C-type lectin receptors (CLRs). Cytoplasmic PRRs include NOD-like ...
... can "hide" mannose antigens on the surface of host cells or bacteria from mannose-binding lectin.[citation needed] ... A recent genome level study examined a large set of sequenced microbial genomes, which indicated that biosynthetic pathways to ... This prevents activation of complement. Sialic acid in the form of polysialic acid is an unusual posttranslational modification ... Mandal, C.; Mandal, C. (1990). "Sialic acid binding lectins". Experientia. 46 (5): 433-441. doi:10.1007/BF01954221. PMID ...
The complement pathway is composed of several subset pathways: the lectin/mannose pathway, alternative pathway and the ... macrophages which are unable to bind the Fc portion of the C1q antibody), leading to further complications. This seems to be ... classical complement pathway). In brief, the crucial role of C1q in the pathway is its importance as the first protein to start ... in the complement pathway) named C1-inhibitor. The inhibition of C1-inhibitor leads to over-activation of the complement ...
Selander B, Mårtensson U, Weintraub A (2006). "Mannan-binding lectin activates C3 and the alternative complement pathway ... Jack DL, Read RC, Tenner AJ (2001). "Mannose-Binding Lectin Regulates the Inflammatory Response of Human Professional ... Hartshorn KL, Sastry K, White MR, (1993). "Human Mannose-binding Protein Functions as an Opsonin for Influenza A Viruses". J. ... Watford WT, Ghio AJ, Wright JR (2000). "Complement-mediated host defense in the lung". Am J Physiol Lung Cell Mol Physiol 279: ...
"Two lineages of mannose-binding lectin-associated serine protease (MASP) in vertebrates". Journal of Immunology. 161 (9): 4924- ... complement activation, lectin pathway. • complement activation. • regulation of complement activation. Sources:Amigo / QuickGO ... Complement component 1s (EC 3.4.21.42, C1 esterase, activated complement C1s, complement C overbar 1r, C1s) is a protein ... protein binding. • hydrolase activity. • metal ion binding. • identical protein binding. • serine-type endopeptidase activity. ...
Lectin: starts when lectins bind to mannose on bacteria. Elements of the complement cascade can be found in many non-mammalian ... Both pathways converge in the recruitment and activation of the IKKε/TBK-1 complex, inducing dimerization of transcription ... There are three different complement systems: Classical, alternative, Lectin *Classical: starts when antibody bind to bacteria ... Complement system[edit]. Main article: Complement system. The complement system is a biochemical cascade of the immune system ...
protein binding. • mannose binding. • carbohydrate binding. • monocarboxylic acid transmembrane transporter activity. • ... Basigin interacts with the fourth C-type lectin[better source needed] domain in the receptor Endo180[16] to form a molecular ... cell surface receptor signaling pathway. • decidualization. • pyruvate metabolic process. • response to mercury ion. • response ... cadherin binding. • protein binding involved in cell-cell adhesion. Cellular component. • integral component of membrane. • ...
... can infect dendritic cells (DCs) by this CD4-CCR5 route, but another route using mannose-specific C-type lectin receptors ... The first step in fusion involves the high-affinity attachment of the CD4 binding domains of gp120 to CD4. Once gp120 is bound ... leads to a predominant transmission of the R5 virus through this pathway.[49][50][51] In patients infected with subtype B HIV-1 ... the cDNA and its complement form a double-stranded viral DNA that is then transported into the cell nucleus. The integration of ...
Examples include the genes coding for the proteins TNFα, mannan-binding lectin,[16] CTLA4, TGFβ,[32] DC-SIGN, PLCE1, and ... specifically the C-type lectins called DC-SIGN, mannose receptor and CLEC5A.[32] DC-SIGN, a non-specific receptor for foreign ... and various lines of research have implied a role for T cells and soluble factors such as cytokines and the complement system.[ ... through the innate immune system by augmenting the production of a large group of proteins mediated by the JAK-STAT pathway. ...
... a C-type lectin-like domain in the N-terminus, an EGF-like domain and a complement-binding protein-like domains (same as ... Among them, the inhibitory activity of semisynthetic sulfated tri mannose C-C-linked dimers (STMCs) to P-selectin was shown by ... "Cytoplasmic domain of P-selectin (CD62) contains the signal for sorting into the regulated secretory pathway". Mol. Biol. Cell ... fucose binding. • carbohydrate binding. • sialic acid binding. • protein binding. • calcium ion binding. • metal ion binding. ...
... via sugar-binding proteins called lectins, which recognize specific carbohydrate moieties.[1] Glycosylation is an important ... A mannose sugar is added to the first tryptophan residue in the sequence W-X-X-W (W indicates tryptophan; X is any amino acid ... disorders of lipid glycosylation and disorders of other glycosylation pathways and of multiple glycosylation pathways. No ... the first crystal structure of a protein containing this type of glycosylation has been determined-that of human complement ...
... the classical complement pathway, the alternate complement pathway, and the mannose-binding lectin pathway. The classical ... Complement systemEdit. Main article: Complement system. The complement system is a biochemical cascade of the innate immune ... 12 of which are directly involved in the complement pathways.[1] The complement system is involved in the activities of both ... The B cell waits for the TH cell to bind to the complex. This binding will activate TH cell and it releases cytokines that ...
... mannan binding lectin; MBL) to mannose containing proteins or to carbohydrates on viruses or bacteria ... The lectin pathway for complement activation is triggered by the binding of a serum lectin ( ... lectin pathway - a pathway of complement activation initiated in the absence of antibody by the binding of mannose binding ... lectin complement pathway. (lek\tin). The lectin pathway for complement activation is triggered by the binding of a serum ...
Mannan-Binding Lectin Complement Pathway. *Mannan Binding Lectin Complement Pathway. *Mannose-Binding Lectin Complement Pathway ... Complement Pathway, Mannose-Binding Lectin. Complement activation triggered by the interaction of microbial POLYSACCHARIDES ... Mannose Binding Lectin Complement Pathway. *Mannan-Binding Lectin Pathway (Complement Activation). *Lectin Pathway, Mannan- ... Complement Pathway, Mannose Binding Lectin. *Lectin-Complement Pathway. *Lectin Complement Pathway. *Lectin-Complement Pathways ...
mannose-binding lectin-associated serine protease. MBL. mannose-binding lectin. PT. prothrombin time. SFMI. sunflower mannose- ... Mannose-binding lectin (MBL)-associated serine protease (MASP)-1 contributes to activation of the lectin complement pathway. J ... Selective Inhibition of the Lectin Pathway of Complement with Phage Display Selected Peptides against Mannose-Binding Lectin- ... Selective Inhibition of the Lectin Pathway of Complement with Phage Display Selected Peptides against Mannose-Binding Lectin- ...
The lectin pathway of the complement system is initiated by mannose-binding lectin (MBL)-associated serine proteases, MASP-1, ... The third serine protease of the lectin pathway, MASP-3, was recently shown to be the major activator, and the exclusive ... The third serine protease of the lectin pathway, MASP-3, was recently shown to be the major activator, and the exclusive ... The lectin pathway of the complement system is initiated by mannose-binding lectin (MBL)-associated serine proteases, MASP-1, ...
... the lectin complement pathway on human renal glomerular endothelial cells triggered by high glucose and mannose-binding lectin ... Keywords: High glucose, mannose-binding lectin, complement activation, human renal glomerular endothelial cells ... Key words: High glucose, mannose-binding lectin, complement activation, human renal glomerular endothelial cells. ... This study aimed to investigate the roles of high glucose and mannose-binding lectin (MBL) on the activation of the lectin ...
... to Form Complexes with Mannose-Binding Lectin-Associated Serine Proteases and Activate Complement through the Lectin Pathway. ... to Form Complexes with Mannose-Binding Lectin-Associated Serine Proteases and Activate Complement through the Lectin Pathway," ...
MBL is a C-type lectin that recognizes oligosaccharides on pathogens and activates the complement system via the lectin pathway ... a salivary gland protein that inhibits the function of Mannose Binding Lectin (MBL). ... We showed that MBL is capable of binding B. burgdorferi through its carbohydrate recognition domains, but in vitro complement ... protected by the Ixodes Tick Salivary Lectin Pathway Inhibitor (TSLPI) protein; ...
Therefore, P8 was renamed the tick salivary lectin pathway inhibitor (TSLPI). TSLPI-silenced ticks, or ticks exposed to TSLPI- ... We now discover that P8 interferes with the human lectin complement cascade, resulting in impaired neutrophil phagocytosis and ... Together, our findings suggest an essential role for the lectin complement cascade in Borrelia eradication and demonstrate how ... The classical and alternative complement pathways are important in Borrelia eradication by the vertebrate host. We recently ...
Cholesterol Crystals Activate the Lectin Complement Pathway via Ficolin-2 and Mannose-Binding Lectin: Implications for the ... We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated ... CC activate the classical and the alternative complement pathways, but the role of the lectin pathway is unknown. We ... Plasma levels of mannose-binding lectin and future risk of venous thromboembolism. Research output: Contribution to journal › ...
Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement ... The lectin pathway is initiated by mannose-binding lectin (MBL) or ficolin recognition of carbohydrate structures on the ... Complement-dependent neutralization of influenza virus by a serum mannose-binding lectin. J. Gen. Virol. 75(Part 3):615-622. ... Complement-Mediated Neutralization of Dengue Virus Requires Mannose-Binding Lectin. Panisadee Avirutnan, Richard E. Hauhart, ...
The mannose-binding lectin-associated serine proteases (MASP)-1... ... Activation of the complement system is part of the dysregulated immune response in sepsis. ... It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY. ... The mannose-binding lectin-associated serine proteases (MASP)-1 and -2 activate the lectin pathway of the complement system. ...
1992) Activation of the classical complement pathway by mannose-binding protein in association with a novel C1s-like serine ... Mannose-Binding Lectin Binds to a Range of Clinically Relevant Microorganisms and Promotes Complement Deposition. Olaf Neth, ... Mannose-Binding Lectin Binds to a Range of Clinically Relevant Microorganisms and Promotes Complement Deposition ... Mannose-Binding Lectin Binds to a Range of Clinically Relevant Microorganisms and Promotes Complement Deposition ...
... we found an increased binding of the key lectin pathway components mannose-binding lectin and mannose-binding lectin-associated ... cell wall polymers of Enterococcus faecalis are critical for resistance to complement activation via mannose-binding lectin.. [ ... Our studies indicated that complement activation via the lectin pathway was much stronger on the tagB mutant compared with wild ... To understand the mechanism of lectin pathway inhibition by E. faecalis, we purified and characterized cell wall carbohydrates ...
... microbial surface carbohydrates and mediates opsonophagocytosis directly and by activation of the lectin complement pathway. A ... Mannose-binding lectin (MBL) is a C-type serum lectin that plays a central role in the innate immune response. MBL binds ... Impact of mannose-binding lectin on susceptibility to infectious diseases.. Eisen DP1, Minchinton RM. ... wide variety of clinical isolates of bacteria, fungi, viruses, and parasites are bound by MBL. Three polymorphisms in the ...
The cooperative character of this binding may explain the high sensitivity of diabetic complications to hyperglycaemia. ... and the ensuing complement activation may provide a physiopathological link between enhanced glycation and complement ... Background: Complement activation via the MBL pathway has been proposed to play a role in the pathogenesis of diabetic ... Binding of mannose-binding lectin to fructosamines: a potential link between hyperglycaemia and complement activation in ...
What complement pathways involve C4? - classical. - mannose-binding lectin 26 How is complement a bridge to adaptive immunity ... 1. IgG bound to pathogen-infected cell binds NK cell, Nk cell releases cytokines like IFN-gamma and kills cell. 2. IgE bound to ... CD28 on naive T cell binds B7 on APC. - CD40L on activated T cell binds CD40 on APC ... C3b binds Cr1/2 on B cell and lowers activation threshold and enhances Ab production. - upregulations co-stimulation molecules ...
Describe initiation of the MBL complement pathway. MBL: mannose binding lectin. Produced by the liver in response to infection ... Formation of antigen-antibody complexes activates which complement pathway? Starts with which protein? ... Binds to carbohydrates found on many pathogens including multiple bacteria, viruses and yeasts. In blood MBL is complexed with ... SLE: The classical pathway clears necrotic and apoptotic cells. Failure leads to build up of self antigens especially nuclear ...
On binding to a ligand, MBL may activate the lectin pathway of complement via the MBL-associated serine protease 2.7-9 Human ... Matsushita M, Fujita T. Activation of the classical complement pathway by mannose-binding protein in association with a novel ... Complement activation after oxidative stress: role of the lectin complement pathway. Am J Pathol. 2000; 156: 1549-1556. ... because MBL-associated serine protease 2 initiates activation of the lectin pathway of complement.9 Complement has been ...
... hence preventing cleavage of C4 and C2 mannan-binding lectin lectin pathway Degn SE, Hansen AG, Steffensen R, Jacobsen C, ... Mannose-binding lectin-associated protein of 44 kDa (MAp44) is a protein arising from the human MASP1 gene. MASP-1, MASP-3 and ... protein associated with pattern recognition molecules of the complement system and regulating the lectin pathway of complement ... MAp44 has been suggested to act as a competitive inhibitor of lectin pathway activation, by displacing MASP-2 from MBL, ...
When bound, this lectin will trigger the complement pathway resulting in opsonization. Mannose-binding protein is also an acute ... Mannose-binding protein is a component of the innate or natural immune system which binds to mannose residues on a variety of ... This test is used as an initial screening for suspected deficiency in the lectin complement pathway. ... Abnormal mannose-binding protein concentrations have been found in patients with infectious disorders such as tuberculosis, ...
However, the involvement of the lectin pathway of complement, a key mediator of oxidative damage, is controversial. This study ... Association Study of Mannose-Binding Lectin Levels and Genetic Variants in Lectin Pathway Proteins with Susceptibility to Age- ... investigated whether mannose-binding lectin (MBL) levels and genetic variants in lectin pathway proteins, are associated with ... SNPs of lectin pathway proteins investigated in this study were not associated with AMD or AMD severity. However, MBL levels ...
... that binds to a bacterium or other pathogen and causes it to become more susceptible to the... ... n. A substance, such as an antibody or complement protein, ... The emerging role of complement lectin pathway in ... MBL works as opsonin and initiates lectin complement activation pathway [20].. The Role of Mannose-Binding Lectin Serum Level ... A substance, such as an antibody or complement protein, that binds to a bacterium or other pathogen and causes it to become ...
Mannose-binding lectin and mannose-binding lectin-associated serine protease 2 in susceptibility, severity, and outcome of ... Two factors of the lectin pathway of complement, l-ficolin and mannan-binding lectin, and their associations with prematurity, ... Deficient mannose-binding lectin-mediated complement activation despite mannose-binding lectin-sufficient genotypes in an ... The role of mannose-binding lectin in pneumococcal infection.. *Association between mannose-binding lectin and HIV infection ...
T. Sprong, T. E. Mollnes, C. Neeleman et al., "Mannose-binding lectin is a critical factor in systemic complement activation ... Involvement of Complement Lectin Pathway in Septic Shock. Specific factors in complement lectin pathway include MBL and ficolin ... M. Matsushita and T. Fujita, "Activation of the classical complement pathway by mannose-binding protein in association with a ... Involvement of Complement Classical Pathway in Septic Shock. Specific factors in complement classical pathway include ...
Origin of mannose-binding lectin-associated serine protease (MASP)-1 and MASP-3 involued in the lectin complement pathway ... Origion of mannose-binding lectin-associated serine protrease (MASP)-1 and MASP-3 involved in the lectin complement pathway ... Origin of mannose-binding lectin-associated serine Protease (MASP)-1 and MASP-3 involved in the lectin complement pathway ... complement / Lectin pathway / MBL / ficolin / MASP / Servine protease / レクチン / ficolin. Research Abstract. Mannose-binding ...
Mannose-Binding Lectin. *. 28. Which immunolglobulin(s) help(s) initiate the classic complement pathway? ... C-type lectin inhibitory receptors on effector cell binding to class I on target cell ... Which complement component is found in both the classic and alternative pathways? ... A serological reaction is set up in which the antigen is bound to a larger carrier, the antibody is soluble, and they bind and ...
The anti-viral mechanisms of MBL include activation of the lectin complement pathway and coagulation, requiring serum factors. ... Background: Mannose-binding lectin (MBL), a pattern recognition innate immune molecule, inhibits influenza A virus infection in ... Lack of the Pattern Recognition Molecule Mannose-Binding Lectin Increases Susceptibility to Influenza A Virus Infection. ... Lack of the pattern recognition molecule mannose-binding lectin increases susceptibility to influenza A virus infection. BMC ...
Certain genetic factors (such as polymorphisms in the genes for mannose-binding lectin and tumor necrosis factor) may also be ... Risk factors for the development of meningococcal disease include deficiencies in the terminal common complement pathway, ... Persons with complement component deficiency, functional or anatomic asplenia or HIV infection who have already received 1 dose ... Persons with persistent complement component deficiency, and persons with functional or anatomic asplenia should receive a 2- ...
Hisano S, Matsushita M, Fujita T, Endo Y, Takebayashi S. Mesangial IgA2 deposits and lectin pathway-mediated complement ... Mannose binding lectin (MBL) is a molecule that shares many features with C1q. MBL comprises a trimer of three identical ... Sasaki K, Tsutsumi A, Wakamiya N, Ohtani K, Suzuki Y, Watanabe Y, et al. Mannose-binding lectin polymorphisms in patients with ... Ogden CA, deCathelineau A, Hoffmann PR, Bratton D, Ghebrehiwet B, Fadok VA, et al. C1q and mannose binding lectin engagement of ...
Mannose-binding lectin (MBL) and MBL-associated serine proteases initiate lectin pathway of complement activation. Animal ... The first pathway involves such pro-inflammatory factors that get released by nuclear gene expression mediated by ... Depletion of these cells or pharmacological blockade of IL-17 and IL-23 pathways suppressed brain damage in a mouse model [44 ... Magnesium has a multi-pathway neuro-protective effect, as it antagonizes calcium channels, it is also a non-competitive NMDA ...
  • Mannan-binding lectin pathway - Natta projection of mannose in its α D mannopyranose form. (academic.ru)
  • MBL) to mannose-containing proteins or to carbohydrates on viruses or bacteria. (academic.ru)
  • lectin pathway - a pathway of complement activation initiated in the absence of antibody by the binding of mannose binding lectin (MBL) to carbohydrates on the surface of microorganisms. (academic.ru)
  • complement - Ehrlich term for the thermolabile substance, normally present in serum, that is destructive to certain bacteria and other cells sensitized by a specific c. fixing antibody. (academic.ru)
  • Complement system - This article is about an aspect of the immune system. (academic.ru)
  • The complement system helps or "complements" the ability of antibodies and phagocytic cells to clear pathogens from an organism. (academic.ru)
  • MBL and MASP-2 serum levels, as well as lectin pathway activity with regard to MBL2 and MASP2 genotypes, were measured in healthy control subjects. (unboundmedicine.com)
  • Mannose-binding lectin 2 gene (MBL2) has been reported to be correlated with different cardiac conditions. (springer.com)
  • Within the MBL2 gene are seven "secretor" haplotypes that code for altered serum MBL levels and complement activation. (ahajournals.org)
  • As complement is important in the pathophysiology of myocardial injury, we determined if MBL2 secretor haplotypes are independently associated with an increased risk of in-hospital, postoperative MI in patients undergoing CABG surgery. (ahajournals.org)
  • We aimed to examine whether genetic variants of the Ficolin-2 (FCN2), Mannose-binding lectin (MBL2) and Complement factor H (CFH) genes, which are involved in activation and regulation of the complement system, are associated with leprosy in Han Chinese from Southwest China. (cdc.gov)
  • A total of 141 patients, 65 exposed asymptomatic exhibition staff members and 670 unexposed blood bank donors were included for the study of MBL2 genotypes and MBL-mediated complement activation. (cdc.gov)
  • It consists of ∼30 proteins (circulating in the serum or membrane bound) forming a sophisticated molecular network capable of recognizing, tagging, and eliminating invading pathogen microorganisms and altered host cells (e.g., apoptotic and necrotic cells) via Ab-independent mechanisms ( 1 ). (jimmunol.org)
  • The complement cascade is composed of more than 30 proteins. (frontiersin.org)
  • The complement system consists of approximately 30 proteins and its main functions are killing of pathogens by lysis through the membrane attack complex (MAC), activation and attraction of leukocytes and opsonisation of pathogens for phagocytosis by leukocytes 7 . (nature.com)
  • The expression of these proteins varies between different B. burgdorferi s.l. strains, making some strains more susceptible to eradication by the complement system than others 11 . (nature.com)
  • We investigated the binding of the PRMs mannose-binding lectin (MBL), ficolin-1, ficolin-2, and ficolin-3, the associated serine proteases, and complement activation products to CC in vitro using recombinant proteins, specific inhibitors, as well as deficient and normal sera. (regionh.dk)
  • Lectins are a group of carbohydrate-binding proteins, which play an important role in innate immune system against pathogen infection. (bioportfolio.com)
  • Association Study of Mannose-Binding Lectin Levels and Genetic Variants in Lectin Pathway Proteins with Susceptibility to Age-Related Macular Degeneration: A Case-Control Study. (sigmaaldrich.com)
  • This study investigated whether mannose-binding lectin (MBL) levels and genetic variants in lectin pathway proteins, are associated with the predisposition to and severity of AMD. (sigmaaldrich.com)
  • SNPs of lectin pathway proteins investigated in this study were not associated with AMD or AMD severity. (sigmaaldrich.com)
  • It was initially believed that MBL-A and MBL-C were found in serum and the liver, respectively, but recently it was shown that both proteins are found in serum in comparable amounts and that both have similar capacities to activate complement ( 12 ). (asm.org)
  • Although it has been shown that the two proteins are distinct in binding-site architecture and multimeric complexity, with some fine differences in specificities for monosaccharides ( 3 , 20 , 21 , 32 ), it is currently unknown whether they have nonoverlapping functions or recognize different sets of microbes. (asm.org)
  • MBL) to mannose-containing proteins or to carbohydrates on viruses or bacteria. (academic.ru)
  • Lectin - Lectins are sugar binding proteins which are highly specific for their sugar moieties. (academic.ru)
  • This communication describes the use of an array of synthetic peptides to identify variants of a linear Fg binding motif present in Coa and Efb which are responsible for the Fg binding activities of these proteins. (asm.org)
  • An alanine scanning approach allowed us to identify the residues in Coa and Efb that are critical for Fg binding and to define the Fg binding motifs in the two proteins. (asm.org)
  • The complement system consists of a number of small proteins found in the blood, in general synthesized by the liver , and normally circulating as inactive precursors ( pro-proteins ). (wikipedia.org)
  • Over 30 proteins and protein fragments make up the complement system, including serum proteins , and cell membrane receptors . (wikipedia.org)
  • Most of the proteins and glycoproteins that constitute the complement system are synthesized by hepatocytes . (wikipedia.org)
  • Protein involved in the complement activation lectin pathway which activates the proteins of the complement system. (uniprot.org)
  • The decreased expression of complement regulatory proteins (CRP) seems to play an important role in RA activity, and is associated with worsening of the clinical symptoms. (scielo.br)
  • rheumatoid arthritis, complement system proteins, complement activation. (scielo.br)
  • The complement system (CS) is composed of receptors and regulators bound to the cell membrane and different plasma proteins that interact with cells and mediators of the immune system ( Figure 1 ). (scielo.br)
  • Mechanisms involve competitive inhibition of carbohydrate binding within sets of defined proteins, in contrast to broadly indiscriminate, irreversible glycation of proteins. (wellnessresources.com)
  • The complement system consist of a complex family of proteins and receptors which are found in the circulation, in tissues and other body-fluids. (linscottsdirectory.com)
  • Complement activation proceeds in a sequential fashion through the proteolytic cleavage of a series of proteins leading to the generation of activated products that mediate various biological activities through their interaction with specific cellular receptors and other serum proteins The three pathways, designated classical, lectin and alternative pathway, converge at a central component into a final common pathway. (linscottsdirectory.com)
  • Several intracellular proteins, such as lectins, chaperones and glycan-processing enzymes, are involved in this process. (hmdb.ca)
  • The complement system - part of the immune system as a set of complex proteins. (allbest.ru)
  • We show that RegIIIγ and its human counterpart, HIP/PAP, are directly antimicrobial proteins that bind their bacterial targets via interactions with peptidoglycan carbohydrate. (sciencemag.org)
  • We propose that these proteins represent an evolutionarily primitive form of lectin-mediated innate immunity, and that they reveal intestinal strategies for maintaining symbiotic host-microbial relationships. (sciencemag.org)
  • The complement system consists of a number of small proteins found in the blood, normally circulating as inactive zymogens . (wikidoc.org)
  • The complement system consists of a specific group of proteins that play a pivotal role in the innate immune response, inflammation and homeostasis. (arp1.com)
  • In response to the recognition of a potential pathogen, inactive complement proteins interact with each other in an enzymatic cascade and become sequentially activated. (arp1.com)
  • Isolation and characterization of two distinct mannan-binding proteins from rat serum. (semanticscholar.org)
  • article{Oka1988IsolationAC, title={Isolation and characterization of two distinct mannan-binding proteins from rat serum. (semanticscholar.org)
  • Two binding proteins, which are specific for mannose and N-acetylglucosamine, were isolated from rat serum to homogeneity. (semanticscholar.org)
  • In vivo recognition of mannosylated proteins by hepatic mannose receptors and mannan-binding protein. (semanticscholar.org)
  • There are several proteins which stabilize or regulate C3 convertase activation via the alternative or lectin pathways. (biomedcentral.com)
  • Complement is the term used to describe a group of serum proteins that are critically important in our defense against infection. (primaryimmune.org)
  • The complement system consists of more than 30 proteins, present in blood and tissues, as well as other proteins anchored on the surfaces of cells. (primaryimmune.org)
  • Complement proteins in the circulation are not activated until triggered by an encounter with a bacterial cell, a virus, an immune complex, damaged tissue or other substance not usually present in the body. (primaryimmune.org)
  • The circulating proteins have been grouped into three activation pathways, based on the types of substances and proteins that initiate the activation. (primaryimmune.org)
  • Complement activation triggered by the interaction of microbial POLYSACCHARIDES with serum MANNOSE-BINDING LECTIN resulting in the activation of MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. (nih.gov)
  • In this paper, we report lectin pathway-specific short peptide inhibitors developed by phage display against mannose-binding lectin-associated serine proteases (MASPs), MASP-1 and MASP-2. (jimmunol.org)
  • Both peptides block the lectin pathway activation completely while leaving the classical and the alternative routes intact and fully functional, demonstrating that of all complement proteases only MASP-1 and/or MASP-2 are inhibited by these peptides. (jimmunol.org)
  • Key components of the complement system are serine proteases (SPs) that are present in the circulation as zymogens ( 2 ). (jimmunol.org)
  • During complement activation, these proteases activate each other in a cascade-like manner. (jimmunol.org)
  • In an attempt to explain this phenomenon, we modeled the basal level fluid-phase activation of lectin pathway proteases and their subsequent inactivation by C1 inhibitor and antithrombin using available and newly determined kinetic constants. (frontiersin.org)
  • The mannose-binding lectin-associated serine proteases (MASP)-1 and -2 activate the lectin pathway of the complement system. (bioportfolio.com)
  • Serum serine proteases which participate in COMPLEMENT ACTIVATION. (bioportfolio.com)
  • They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). (bioportfolio.com)
  • This protein is able to activate the complement pathway in an antibody-independent manner via cooperation with MBL-associated serine proteases (MASP). (ithanet.eu)
  • Quantitative Characterization of the Activation Steps of Mannan-binding Lectin (MBL)-associated Serine Proteases (MASPs) Points to the Central Role of MASP-1 in the Initiation of the Complement Lectin Pathway. (doktori.hu)
  • It binds multiple bacterial monosaccharides (mannose, N-acetylglucosamine, N-acetylmannosamine, and L-fucose) and activates associated serine proteases ( MASP-2 , MASP-1 ), which in turn activate the classical pathway. (sinobiological.com)
  • Mannose binding lectin (MBL), the Ficolins, and Collectin can initiate the LP. Associated with these are enzymes referred to as MASPs (MBL-Associated Serine Proteases). (primaryimmune.org)
  • In this study, we identified an insertional mutant of the wall teichoic acid (WTA) synthesis gene tagB in E. faecalis V583 that exhibited an increased susceptibility to complement-mediated killing by neutrophils. (sigmaaldrich.com)
  • Impact of mannose-binding lectin on susceptibility to infectious diseases. (nih.gov)
  • In age-related macular degeneration (AMD) the complement system is thought to be activated by chronic oxidative damage with genetic variants identified in the alternative pathway as susceptibility factors. (sigmaaldrich.com)
  • We conclude that high glucose disrupts C-type lectin function, potentially illuminating new perspectives on susceptibility to infectious and inflammatory disease in diabetes. (wellnessresources.com)
  • Alterations in the alternative pathway, like properdin or ficolin deficiency, increase the susceptibility to infection. (linscottsdirectory.com)
  • Hence, the most powerful use of mouse models is the identification of genes and their respective biochemical pathways that are involved in disease susceptibility rather than the identification of specific susceptibility/resistance gene variants. (aspetjournals.org)
  • The Mannose-Binding Lectin: An Infection Susceptibility Gene. (indigo.ca)
  • The complement system plays multiple roles in host defense against infection and is supposed to confer genetic susceptibility to leprosy. (cdc.gov)
  • Our data confirmed the expected positive association of complement genes with leprosy susceptibility and clinical outcomes in Han Chinese. (cdc.gov)
  • The aim of this study was to ascertain whether mannose binding lectin deficiency is implicated in coexistent rheumatoid arthritis and bronchiectasis and to determine whether undetectable mannose bindi. (bioportfolio.com)
  • This test is used as an initial screening for suspected deficiency in the lectin complement pathway. (uiowa.edu)
  • A deficiency in any component of the classical pathway is associated with an increased risk of immunological disease and recurrent bacterial infections. (asmscience.org)
  • Mannose-binding Lectin deficiency. (allbest.ru)
  • We found that deletion of C3, fB, fP, C3aR, or C5aR significantly ameliorated renal IRI in DAF(-/-)CD59(-/-) mice, whereas deficiency of C4, Ig, or mannose-binding lectin had no effect. (jove.com)
  • In this research, we studied the formation of Drosophila melanogaster FADD (Fas-associated death domain-containing protein) amyloid fiber and its influence on signal transduction in IMD (Immune deficiency) signaling pathway to better understand the regulation mechanism of Drosophila innate immune signaling pathway, which will provide reference for the immune regulation in other species. (bvsalud.org)
  • Mannose-binding lectin / MBL deficiency has been reported in 2-7% of the British population. (sinobiological.com)
  • 2010). Complement: deficiency diseases. (sinobiological.com)
  • 1991). Complement deficiency and disease. (sinobiological.com)
  • C1q knock-out mice for the study of complement deficiency in autoimmune disease. (sinobiological.com)
  • 2006). Complement deficiency and disease: an update. (sinobiological.com)
  • Polymorphisms leading to deficiency of mannose-binding lectin (MBL) are associated with predisposition to infection. (cdc.gov)
  • Together, these genotypical and functional data suggest that the observed deficiency of lectin pathway activation is an effect of legionellosis rather than a risk factor for acquiring it. (cdc.gov)
  • Moreover, the complement system bridges the innate and adaptive immunity, because the activated complement components facilitate the phagocytosis of pathogens by the host's leukocytes and initiate inflammatory reactions by recruiting and stimulating the cellular elements of the immune system. (jimmunol.org)
  • MBL is a C-type lectin that recognizes oligosaccharides on pathogens and activates the complement system via the lectin pathway. (nature.com)
  • It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY. (bioportfolio.com)
  • In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. (asm.org)
  • The complement system is part of our first line of defense against invading pathogens. (sigmaaldrich.com)
  • To rapidly cleanse the blood of pathogens, the patient's blood is mixed with magnetic nanobeads coated with a genetically engineered version of a human blood ' opsonin ' protein that binds to a wide variety of bacteria, fungi, viruses, parasites, and toxins. (thefreedictionary.com)
  • To examine the physiological functions of mannose-binding lectin A (MBL-A), we generated mice that were deficient in MBL-A and examined their susceptibilities to the microbial pathogens Candida albicans and Plasmodium yoelii , an accepted experimental malaria model in mouse. (asm.org)
  • Indeed, MBL has been shown to bind a host of pathogens, including subsets of gram-positive and gram-negative bacteria, Mycobacterium tuberculosis , and Candida albicans ( 5 , 31 ). (asm.org)
  • The complement system helps or "complements" the ability of antibodies and phagocytic cells to clear pathogens from an organism. (academic.ru)
  • Serum MBL can directly opsonize pathogens and enhance the activity of phagocytotic cells or it can activate complement through the lectin pathway. (jrheum.org)
  • Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. (beds.ac.uk)
  • The classical complement pathway typically requires antigen-antibody complexes for activation (specific immune response), whereas the alternative pathway can be activated by spontaneous C3 hydrolysis, foreign material, pathogens, or damaged cells. (wikipedia.org)
  • The Mannose-Binding Lectin Complement Pathway is activated when mannose-binding lectin binds to mannose found on the surface of pathogens. (meta.org)
  • The classical pathway is initiated by binding of C1q to antibody complexes, whereas the alternative and lectin pathway are activated in an antibody-independent fashion through the interaction of complement components with respectively specific carbohydrate groups and lipopolysaccharides (LPS) on the surface of foreign pathogens. (linscottsdirectory.com)
  • It is derived from liver and secreted in plasma, where it binds sugar residues, such as mannose, fucose and N-acetylglucosamine on the surface of pathogens, leading to their opsonization and phagocytosis by specialized immune cells. (ithanet.eu)
  • C3b binds to the surface of pathogens, leading to greater internalization by phagocytic cells by opsonization. (technologynetworks.com)
  • Kupffer cells and other macrophage cell types help clear complement-coated pathogens. (technologynetworks.com)
  • The complement system is a biochemical cascade which helps clear pathogens from an organism. (wikidoc.org)
  • High levels of mannose-binding lectin (MBL), an activator of a part of the immune system called the complement system, have been associated with increased mortality and risk of early signs. (bioportfolio.com)
  • Together, our findings suggest an essential role for the lectin complement cascade in Borrelia eradication and demonstrate how a vector-borne pathogen co-opts a vector protein to facilitate early mammalian infection and vector colonization. (prohealth.com)
  • Using a panel of naïve sera from mouse strains deficient in different complement components, we showed that inhibition of infection by insect cell- and mammalian cell-derived DENV was primarily dependent on the lectin pathway. (asm.org)
  • Human MBL also bound to DENV and neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. (asm.org)
  • Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation, neutralized infection of all four DENV serotypes through complement activation-dependent and -independent pathways. (asm.org)
  • Identification and characterization of a B-type mannose-binding lectin from Nile tilapia (Oreochromis niloticus) in response to bacterial infection. (bioportfolio.com)
  • Lysozyme is an important component in the nonspecific humoral immune which possess both bactericidal as well as opsonin effects that activate the complement system and phagocytes to prevent infection and disease. (thefreedictionary.com)
  • While complement is an important defense system against bacterial infection, earlier clinical observations suggest that activation of complement factors is associated with detrimental effects in septic shock, such as multiorgan damages and poor outcome [ 5 - 8 ]. (hindawi.com)
  • Background: Mannose-binding lectin (MBL), a pattern recognition innate immune molecule, inhibits influenza A virus infection in vitro. (harvard.edu)
  • Capparelli R, Parlato M, Amoroso MG, Roperto S, Marabelli R, Roperto F, Iannelli D (2008) Mannose-binding lectin haplotypes influence Brucella abortus infection in the water buffalo ( Bubalus bubalis ). (springer.com)
  • These sugars are found on the surfaces of bacteria and fungi and act as targets for receptors in our body that have evolved to detect and bind to microbial sugars to then combat the infection. (wellnessresources.com)
  • Mannose binding lectin (MBL), a major component of the lectin pathway, is associated with bacterial, fungal and viral infection. (linscottsdirectory.com)
  • Mannose-binding lectin and ficolin-2 gene polymorphisms predispose to cytomegalovirus (re)infection after orthotopic liver transplantation. (cdc.gov)
  • SARS-CoV-2 primarily infection is initiated when the host cell angiotensin-converting enzyme 2 (ACE2) surface receptor is bound by the virus' spike (S) protein through its receptor binding domain (RBD). (antibodies-online.com)
  • The primary functions of the complement system are to protect from infection, to remove particulate substances, (like damaged or dying cells, microbes or immune complexes) and to help modulate adaptive immune responses. (primaryimmune.org)
  • The complement system, as an essential part of the innate immune response, eliminates invading microorganisms and dangerous host cells ( 1 , 2 ). (frontiersin.org)
  • Here, we report such a study in which, by using flow cytometry, it has been possible to detect major differences in the MBL binding capacities of different microorganisms and even differences among organisms of the same genus. (asm.org)
  • Mannose-binding protein is a component of the innate or natural immune system which binds to mannose residues on a variety of different microorganisms. (uiowa.edu)
  • lectin pathway - a pathway of complement activation initiated in the absence of antibody by the binding of mannose binding lectin (MBL) to carbohydrates on the surface of microorganisms. (academic.ru)
  • The protein recognizes mannose and N-acetylglucosamine on many microorganisms, and is capable of activating the classical complement pathway. (origene.com)
  • It binds microorganisms and apoptotic cells through the carbohydrate recognition domain. (jrheum.org)
  • Compared to other microorganisms, such as Escherichia coli , Staphylococcus aureus and Cryptococcus neoformans , C. parapsilosis and Candida albicans were potent activators of the lectin pathway. (beds.ac.uk)
  • Binds mannose, fucose and N-acetylglucosamine on different microorganisms and activates the lectin complement pathway. (uniprot.org)
  • Since MBL initiates the lectin complement pathway that mediates the innate immune system, SEGAP may activate the defense system against invading microorganisms. (nii.ac.jp)
  • These results suggest that SEGAP induces lectin, CT-1 and iNOS mRNA expressions in order to protect sperm from invading microorganisms. (nii.ac.jp)
  • Mannose-binding lectin (MBL) is a member of the collectin protein family that binds a broad range of microorganisms and activates the lectin-complement pathway of innate immunity. (springer.com)
  • The complement system provides a fundamental component of the body's immune response to invading microorganisms. (asmscience.org)
  • Mannose-binding lectin (MBL) is a C-type lectin secreted by the liver as a component of the acute-phase immune response, and its binding to carbohydrate structures on microorganisms activates the MBL complement pathway ( 4 , 5 ). (diabetesjournals.org)
  • In the case of the classical and the lectin pathways, collagen-containing pattern recognition molecules bind to Ag-Ab complexes and carbohydrate residues, respectively, on the surface of the pathogenic cells. (jimmunol.org)
  • We hypothesized that the pattern recognition molecules (PRMs) from the lectin pathway bind CC and function as an upstream innate inflammatory signal in the pathophysiology of atherosclerosis. (regionh.dk)
  • Publications] Ohsawa I: 'Cryoprecipitate of patients with cryoglobulinemic glomerulonephritis contains molecules of the lectin complement pathway'Clin. (nii.ac.jp)
  • The lectin pathway is activated by carbohydrate recognition molecules that bind to polysaccharide on the surface of a pathogen. (asmscience.org)
  • The system consist of three defined pathways which are activated by a pathway specific panel of molecules. (linscottsdirectory.com)
  • The encoded protein is synthesized as a zymogen and is activated when it complexes with the pathogen recognition molecules of lectin pathway, the mannose-binding lectin and the ficolins. (antikoerper-online.de)
  • The classical pathway is triggered by activation of the C1-complex (which consists of one molecule C1q and two molecules C1r and C1s), either by C1q's binding to antibodies from classes M and G, complexed with antigens , or by its binding C1q to the surface of the pathogen. (wikidoc.org)
  • Here, we document the pivotal role of mannose-binding lectin (MBL), one of the recognition molecules of the lectin complement pathway, in brain ischemic injury. (elsevier.com)
  • 2, 3 Leukocyte activation is a multistep process consisting of rolling, firm adhesion and transmigration and is mediated by a complex interaction between adhesion molecules in response to chemoattractants such as complement factors, chemokines, or platelet-activating factor. (jove.com)
  • 4 While leukocyte rolling in postcapillary venules is predominantly mediated by the interaction of selectins 5 with their counter ligands, firm adhesion of leukocytes to the endothelium is selectin-controlled via binding to intercellular adhesion molecules (ICAM) and vascular cellular adhesion molecules (VCAM). (jove.com)
  • Therefore, we focused on molecules stabilizing and regulating the alternative pathway C3 convertase in urine which might be associated with IgAN pathogenesis. (biomedcentral.com)
  • The microbe-specific molecules that are recognized by a given PRR are called pathogen-associated molecular patterns (PAMPs) and include bacterial carbohydrates (such as lipopolysaccharide or LPS, mannose), nucleic acids (such as bacterial or viral DNA or RNA), bacterial peptides (flagellin, microtubule elongation factors), peptidoglycans and lipoteichoic acids (from Gram-positive bacteria), N-formylmethionine, lipoproteins and fungal glucans and chitin. (wikipedia.org)
  • Interaction of TLRs with their specific PAMP is mediated through either MyD88- dependent pathway and triggers the signaling through NF-κB and the MAP kinase pathway and therefore the secretion of pro-inflammatory cytokines and co-stimulatory molecules or TRIF - dependent signaling pathway. (wikipedia.org)
  • We showed that MBL is capable of binding B. burgdorferi through its carbohydrate recognition domains, but in vitro complement killing assays, peritoneal macrophage and whole blood stimulations, phagocytosis assays and an in vivo migration experiment did not reveal the mechanism by which MBL facilitates early clearance of B. burgdorferi . (nature.com)
  • We now discover that P8 interferes with the human lectin complement cascade, resulting in impaired neutrophil phagocytosis and chemotaxis and diminished Borrelia lysis. (prohealth.com)
  • MBL is a serum lectin that mediates phagocytosis and activates the lectin pathway of complement involving MASP-2. (unboundmedicine.com)
  • The outer membrane is surrounded by a polysaccharide capsule that is necessary for pathogenicity because it helps the bacteria resist phagocytosis and complement-mediated lysis. (cdc.gov)
  • Once bound to microbes, MBL is believed to act as an opsonin for phagocytosis ( 17 ) and to activate the complement cascade via mannose-binding lectin-associated protein 2 (MASP-2) for microbial lysis ( 28 , 34 , 39 ). (asm.org)
  • Mannose-binding lectin (MBL) plays an important role in innate immunity mediating phagocytosis and activating the MBL complement pathway. (meta.org)
  • Mannose binding lectin (MBL) activates complement pathway that leads to pathogen opsonization and phagocytosis. (escholarship.org)
  • Upon this binding, the recognition molecule-associated SPs become activated and initiate the proteolytic cascade ( 3 ). (jimmunol.org)
  • A tick mannose-binding lectin inhibitor interferes with the vertebrate complement cascade to enhance transmission of the lyme disease agent. (prohealth.com)
  • Prior studies showed that MBL-dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. (asm.org)
  • Importantly, in the past years, synaptic pruning was found to be determined by the microglial chemokine receptor C[X.sub.3]CR1 and the classical complement cascade, including, most notably, signaling between the microglial complement receptor 3 (CR3) and the neuronal opsonin C3 [21, 28]. (thefreedictionary.com)
  • Basic and clinical studies suggest that activation of complements in the common cascade, for example, complement component 3 (C3) and C5, is involved in the development of septic shock. (hindawi.com)
  • Different initiators activate each pathway but all converge to complement protein C3 and are followed by a common cascade (C5-9), resulting in the deposition of a membrane-attack-complex on targets and the release of chemoattractants (C3a and C5a) for inflammatory cells. (hindawi.com)
  • The innate immune response provides the first line of defense against Streptococcus pyogenes infections, in the case of RF, with complement cascade activation. (springer.com)
  • The end result of this complement activation or complement fixation cascade is stimulation of phagocytes to clear foreign and damaged material, inflammation to attract additional phagocytes, and activation of the cell-killing membrane attack complex . (wikipedia.org)
  • The complement activation is tightly regulated by membrane-bound and fluid-phase regulatory components to avoid runaway activation of the enzymatic cascade that could lead to excess host tissue damage, inflammation, and depletion of complement components. (asmscience.org)
  • The ELISA contains a positive control which can be used as process control to ensure that the classical complement cascade has run completely. (linscottsdirectory.com)
  • The lectin pathway is one of the three activation pathways of the complement activation cascade that can recognise and respond to structures on oxygen deprived cells and contribute to ischaemia and reperfusion injury (IRI). (bl.uk)
  • In all three pathways, C3-convertase cleaves and activates component C3, creating C3a and C3b, and causes a cascade of further cleavage and activation events. (technologynetworks.com)
  • Adjacent to the production of reactive oxygen species, activation of the complement system and increased microvascular permeability, the activation of leukocytes is one of the principle actors in the pathological cascade of inflammatory tissue damage during reperfusion. (jove.com)
  • Our study revealed the role of dFADD in mediating the cascade between IMD and Dredd in the IMD signaling pathway by forming amyloid fibers, suggesting an evolutionarily conserved regulatory mechanism of innate immune signaling pathway. (bvsalud.org)
  • PRR binding sets off a cascade of events that activates immune responses. (bvsalud.org)
  • If you visualize a trident, the three tines represent the different initiation routes, while the handle represents the lytic mechanism by which this cascade ultimately destroys the threat, no matter which activation pathway started the response. (primaryimmune.org)
  • Analysis of the genotypes and haplotypes was used to investigate the polymorphisms and their possible implications, especially their association with serum MBL-A levels, complement activity (CH50 and ACH50), and milk production traits was investigated. (springer.com)
  • Botto M, Fong KY, So AK, Koch C, Walport MJ (1990) Molecular basis of polymorphisms of human complement component C3. (springer.com)
  • We initially located the Fg binding sites to Coa's C-terminal disordered segment containing tandem repeats by using recombinant fragments of Coa in enzyme-linked immunosorbent assay-type binding experiments. (asm.org)
  • Serum complement deficiencies were screened with a total complement activity enzyme-linked immunosorbent assay (ELISA), with further analyzes performed if justified. (lu.se)
  • Mannose-binding lectin (MBL) is a key soluble pathogen recognition protein of the innate immune system that binds specific mannose-containing glycans on the surfaces of microbial agents and initiates complement activation via the lectin pathway. (asm.org)
  • MBL has the potential to express multiple biological effector functions, but a prerequisite for all such activity is primary binding to multiple arrays of sugar ligands such as those expressed on microbial surfaces. (asm.org)
  • MBL binds microbial surface carbohydrates and mediates opsonophagocytosis directly and by activation of the lectin complement pathway. (nih.gov)
  • This motif represents the first Fg binding motif identified for any microbial protein. (asm.org)
  • In this study, we identified for the first time a microbial Fg binding motif. (asm.org)
  • This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. (beds.ac.uk)
  • This chapter highlights the various roles of the complement system in the orchestration of the immune response towards microbial infections, gives examples of microbial strategies to evade complement-mediated clearance, and discusses how acquired and inherited complement deficiencies may predispose an organism to infectious disease. (asmscience.org)
  • This pathway can be activated mainly by mannose-binding lectin (MBL) interacting with carbohydrate structures on microbial surfaces and by ficolins with different fine carbohydrate binding specificity. (uniprot.org)
  • This protein binds through multiple lectin domains to the repeating sugar arrays that decorate many microbial surfaces, and is then able to activate the complement system through a specific protease called MBL-associated protease-2. (hmdb.ca)
  • We measured levels of immunoglobulins (Igs) and complement in 257 hospitalized adults with CAP and examined the association of low levels of Igs or complement to microbial etiology, disease severity, and short-term and long-term outcome. (lu.se)
  • In hospitalized adults with CAP, low admission levels of Igs or complement were in general not associated with microbial etiology, disease severity, short-term outcome, or long-term outcome. (lu.se)
  • Microbial colonization of germ-free mice triggers epithelial expression of RegIIIγ, a secreted C-type lectin. (sciencemag.org)
  • Mannose-binding lectin-associated protein of 44 kDa (MAp44) is a protein arising from the human MASP1 gene. (wikipedia.org)
  • To determine whether occurrence, characteristics, and progression of systemic lupus erythematosus (SLE) are associated with polymorphism of the mannose binding lectin (MBL) gene and with serum MBL concentration. (bmj.com)
  • This gene encodes the soluble mannose-binding lectin or mannose-binding protein found in serum. (origene.com)
  • Brigati C, Kurtz S, Balderes D, Vidali G, Shore D (1993) An essential yeast gene encoding a TTAGGG repeat-binding protein. (springer.com)
  • This gene encodes a major constituent of the human complement subcomponent C1q. (antikoerper-online.de)
  • This gene encodes a serine protease that functions as a component of the lectin pathway of complement activation. (antikoerper-online.de)
  • This gene encodes complement factor B, a component of the alternative pathway of complement activation. (antikoerper-online.de)
  • The protein encoded by this gene is the fifth component of complement, which plays an important role in inflammatory and cell killing processes. (antikoerper-online.de)
  • Reduced Mannose-Binding Lectin-Associated Serine Protease (MASP)-1 is Associated with Disturbed Coagulation in Septic Shock. (bioportfolio.com)
  • MBL is able to bind through multiple sites to various carbohydrate structures ( 29 , 37 ) and, on binding to its ligands, is able to activate complement in an antibody- and C1q-independent manner ( 12 , 24 , 26 ) using MBL-associated serine protease 1 (MASP-1) and MASP-2 ( 23 , 34 ). (asm.org)
  • In concordance, we found an increased binding of the key lectin pathway components mannose-binding lectin and mannose-binding lectin-associated serine protease-2 (MASP-2) on the mutant. (sigmaaldrich.com)
  • On binding to a ligand, MBL may activate the lectin pathway of complement via the MBL-associated serine protease 2. (ahajournals.org)
  • Mannose-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) deficiencies are common primary immunodeficiencies the clinical penetrance of which remains controversial. (unboundmedicine.com)
  • Mannose binding lectin associated serine protease 2 (MASP-2) is the key effector enzyme of the lectin pathway, since depletion of this enzyme completely ablates lectin pathway function or activity. (bl.uk)
  • The serum of mannose-binding lectin-associated serine protease (MASP)-1/3(-/-) mice contains pro-FD and has markedly reduced alternative pathway activity. (nmi.de)
  • Individual chapter topics include the building blocks of the complement system, the classical pathway C1 complex, structure-function relationships in CD59, and cyclic antagonists of human C5a receptors. (thefreedictionary.com)
  • These receptors , which we now call "antibodies," were called by Ehrlich "amboceptors" to emphasise their bifunctional binding capacity: They recognise and bind to a specific antigen, but they also recognise and bind to the heat-labile antimicrobial component of fresh serum. (wikipedia.org)
  • The research found that high levels of glucose outcompetes the binding of mannose and fucose to the specialized immune receptors, potentially blocking these receptors from detecting infectious bacteria and fungi. (wellnessresources.com)
  • It can inhibit the function of immune system receptors called C-type lectins such as MBL (Mannose-binding lectin) which are known to bind to a sugar known as mannose that is present in the structure of infectious fungal bacterial cell walls. (wellnessresources.com)
  • A number of C-type lectins tat can be affected by raised glucose levels, including MBL, but also including immune cell surface receptors DC-SIGN and DC-SIGNR, are found in key parts of our circulation and vascular system such as plasma, monocytes, platelets and endothelial cells that line blood vessels. (wellnessresources.com)
  • We crossed DAF(-/-)CD59(-/-) mice with mice deficient in various complement components or receptors including C3, C4, factor B (fB), factor properdin (fP), mannose-binding lectin, C3aR, C5aR, or Ig and assessed renal IRI in the resulting mutant strains. (jove.com)
  • Membrane-bound PRRs include Toll like receptors (TLRs) and C-type lectin receptors (CLRs). (wikipedia.org)
  • To detect the serum level of mannose binding lectin (MBL) and its genovariation in systemic lupus erythematosus (SLE) patients and to investigate the role of MBL in the pathogenesis of SLE. (meta.org)
  • This study aims to investigate whether an association exists between the ficolins that are part of the lectin complement pathway and systemic lupus erythematosus. (antikoerper-online.de)
  • 1 MBL mediates lectin dependent activation of the complement pathway, 1 and has an important role in host defence against micro-organisms. (bmj.com)
  • MBL also binds and mediates clearance of apoptotic cells and cell debris. (ithanet.eu)
  • We found that naturally occurring IgG recognizing V. cholerae outer membrane protein U (OmpU) mediates a serum-killing effect in a complement C1q-dependent manner. (diva-portal.org)
  • A substance, such as an antibody or complement protein, that binds to a bacterium or other pathogen and causes it to become more susceptible to the action of phagocytes. (thefreedictionary.com)
  • complement - Ehrlich term for the thermolabile substance, normally present in serum, that is destructive to certain bacteria and other cells sensitized by a specific c. fixing antibody. (academic.ru)
  • The pathway by which antigen-antibody complex activates the complement system. (thefreedictionary.com)
  • Subsequent complement activation is similar to the classical complement pathway, but without the need for antigen-antibody complexes. (meta.org)
  • Ag receptor in form of antibody immunoglobulin allows cells to bind to antigens (one way to bind to antigen). (flashcardmachine.com)
  • We have previously demonstrated the role of the lectin pathway in the immune response against B. burgdorferi by the identification and characterisation of the tick salivary gland protein Tick Salivary Lectin Pathway Inhibitor (TSLPI) 12 . (nature.com)
  • Therefore, P8 was renamed the tick salivary lectin pathway inhibitor (TSLPI). (prohealth.com)
  • Mannose-binding lectin, soluble DC-SIGN and DC-SIGNR, and surfactant protein D, were tested for carbohydrate binding in the presence of glucose concentrations typical of diabetes, via surface plasmon resonance and affinity chromatography. (wellnessresources.com)
  • D-Mannose is a carbohydrate. (hmdb.ca)
  • Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis. (asm.org)
  • Complement activation via the MBL pathway has been proposed to play a role in the pathogenesis of diabetic complications. (nih.gov)
  • secondly, we review the literature that addresses the innate immune system, including the complement system and synovial macrophages, in the pathogenesis of OA. (jrheum.org)
  • Mannose-binding lectin (MBL) may play differentiated roles in the pathogenesis of RA. (jrheum.org)
  • OBJECTIVE Mannose-binding lectin (MBL) is an essential component of the acute-phase immune response and may thus play a role in the pathogenesis of type 1 diabetes and diabetic nephropathy. (diabetesjournals.org)
  • Low-grade inflammation and complement activation may, however, play a role in the pathogenesis of both type 1 diabetes and its complications ( 1 - 3 ). (diabetesjournals.org)
  • Role of Complement Receptor 2 in the Pathogenesis of Systematic Lupus Erythematosus. (indigo.ca)
  • Complement is implicated in the pathogenesis of ischemia-reperfusion injury (IRI). (jove.com)
  • Thus, it has been thought that the activation of the alternative pathway plays a crucial role in the pathogenesis of IgAN. (biomedcentral.com)
  • Mannose-binding lectin (MBL), a serum protein belonging to the collectin family, is considered to be a pattern recognition molecule designed to detect pathogen-associated molecular patterns ( 5 ). (asm.org)
  • Mannose-binding lectin (MBL) is an acute phase inflammatory protein and functions as a soluble pathogen recognition receptor. (springer.com)
  • Within the immune system, host-pathogen and regulatory host-host interactions operate through binding of oligosaccharides by C-type lectin. (wellnessresources.com)
  • In addition, many of acquired nonself surfaces e.g. carcinoembryonic/oncofetal type neoantigens carrying "internal danger source"/"self turned nonself" type pathogen pattern are also identified and destroyed (e.g. by complement fixation or other cytotoxic attacks) or sequestered (phagocytosed or ensheathed) by the immune system by virtue of the CLRs. (wikipedia.org)
  • Mannose-binding lectin (MBL) is a pattern recognition receptor (PRR) that plays an important role in the innate immune response. (bioportfolio.com)
  • Mannose-binding lectin (MBL) is a C-type serum lectin that plays a central role in the innate immune response. (nih.gov)
  • The encoded protein is a mannose-binding lectin (MBL) involved in the innate immune response. (ithanet.eu)
  • The complement system constitutes a critical component of the innate immune response. (bl.uk)
  • High glucose inhibited C-type lectin binding to high-mannose glycoprotein and binding of DC-SIGN to fucosylated ligand (blood group B) was abrogated in high glucose. (wellnessresources.com)
  • Stages of activation: the alternative and lectin pathway. (allbest.ru)
  • When the classical or lectin pathways are activated, it results in the formation of the C3 convertase, C4bC2a, composed of the cleaved forms of complement factors C4 and C2 ( 4 ). (frontiersin.org)
  • The three pathways of activation all generate homologous variants of the protease C3-convertase . (wikipedia.org)
  • Both the classical and the lectin pathway share the identical C3 and C5 convertase complexes formed after cleavage of C4 by either activated C1s (classical pathway) or activated MASP-2 (lectin pathway) (see 1) and subsequent cleavage and activation of C4b-bound C2 through activated C1s or MASP-2 (see 2). (asmscience.org)
  • C5 convertase is also formed by the Classical Pathway when C3b binds C4b and C2a. (technologynetworks.com)
  • Because our previous work established that the serum levels of B, P, fH and fI in patients with IgAN were significantly higher than those in healthy controls [ 14 ], we hypothesized that targeting the alternative pathway C3 convertase activation could be therapeutically beneficial in IgAN. (biomedcentral.com)
  • The Terminal Pathway (TP) is the final set of steps in the complement activation process that forms a membrane lesion or hole (membrane attack complex or MAC) that kills susceptible bacteria or other cells that activate complement on their surfaces. (primaryimmune.org)
  • The first EDTA eluate was recalcified to 0.05 M CaCl 2 , reapplied to the same mannan-agarose column, and eluted with 0.1 M mannose. (asm.org)
  • We also performed enzyme-linked immunosorbent assays using purified MBL and fructoselysine-derivatized (binding assay) or mannan-coated plates (inhibition assay). (nih.gov)
  • MAp44 has been suggested to act as a competitive inhibitor of lectin pathway activation, by displacing MASP-2 from MBL, hence preventing cleavage of C4 and C2 mannan-binding lectin lectin pathway Degn SE, Hansen AG, Steffensen R, Jacobsen C, Jensenius JC, Thiel S (December 2009). (wikipedia.org)
  • Publications] Dahl M.R.: 'MASp-3 and its association with distinct complexes of the mannan-binding lectin complement activation pathway'Immunity. (nii.ac.jp)
  • MBL has the capacity to function as an opsonin and has been shown to strongly bind C. albicans , which displays mannan, a candidate ligand for MBL, on its surface ( 14 ). (asm.org)
  • Mannan-binding lectin pathway - Natta projection of mannose in its α D mannopyranose form. (academic.ru)
  • Mannan is a polymer of mannose. (academic.ru)
  • This unit contains protocols that can be used to measure mannan‐binding lectin (MBL) levels and MBL pathway activity in human plasma or serum. (currentprotocols.com)
  • An assay for the mannan‐binding lectin pathway of complement activation. (currentprotocols.com)
  • The level of mannan‐binding protein regulates the binding of complement‐derived opsonins to mannan and zymosan at low serum concentrations. (currentprotocols.com)
  • The fungal cell wall, which consists mainly of polymers of N -acetylglucosamine (chitin), glucose (β-glucan) and mannose (mannan) [ 15 , 24 ] is a candidate ligand for MBL and may be capable of activating the lectin complement pathway. (beds.ac.uk)
  • Recombinant full length protein corresponding to Human Mannan Binding Lectin/MBL aa 21-248. (abcam.com)
  • The minor component [serum mannan-binding protein I (S-MBP-I)] was indistinguishable from rat liver mannan-binding protein (L-MBP). (semanticscholar.org)
  • L-ficolin/P35 binds to MASPs and sMAP with similar dissociation constants to those for the interaction between MBL and MASPs/sMAP. (nii.ac.jp)
  • 3. Hakata antigen activates the lectin pathway in association with MASPs and sMAP. (nii.ac.jp)
  • Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. (asm.org)
  • Serum lectin with known structure activates complement through the classical pathway. (currentprotocols.com)
  • The CRD has been shown to bind mannose, fucose, and N -acetylglucosamine ( 4 ), and the cluster of CRDs rendered by oligomerization is thought to be suitable for binding polymeric sugars found on microbes ( 19 , 42 ). (asm.org)
  • A number of C-type lectins recognise oligosaccharides rich in mannose and fucose - sugars with similar structures to glucose. (wellnessresources.com)
  • The researchers looked at the similarities in chemical structure between glucose in blood and body fluids, and two other sugar called mannose and fucose. (wellnessresources.com)
  • The primary pathway for the formation of L-fucose in procaryotic and eucaryotic cells is from D-mannose via an internal oxidation reduction and then epimerization of GDP-D-mannose to produce GDP-L-fucose. (hmdb.ca)
  • It produces a number of virulence factors (VFs) and, surprisingly, many of these VFs bind Fg with high affinity and specificity. (asm.org)
  • This plays a role on how the structure folds and what its specificity is for things that it binds to. (flashcardmachine.com)
  • Mannose-binding lectin (MBL) is a C-type lectin involved in innate immune defense. (jrheum.org)
  • Calcium-dependent lectin involved in innate immune defense. (uniprot.org)
  • This cleavage activates the terminal complement pathway leading to eventually the formation of the terminal C5b-9 complement complex (TCC). (linscottsdirectory.com)
  • Binding of SARS-CoV-2 to ACE2 triggers priming of the trimeric S protein at the polybasic S1/S2 cleavage site by the cell surface-associated transmembrane protease serine 2 (TMPRSS2) and to a lesser degree cathepsin B and L. The S1 ectodomain containing the RBD determines cellular tropism and attachment of the virus to its target cell. (antibodies-online.com)
  • In vitro , complement C3 and its cleavage product C3b enhanced FVIII endocytosis by dendritic cells and presentation to a FVIII-specific CD4 + T-cell hybridoma. (haematologica.org)
  • Because the ability of the C3b to bind to these surfaces decays rapidly, the activation is limited to just the region around the C3 cleavage site. (primaryimmune.org)
  • Complement regulatory protein genes in channel catfish and their involvement in disease defense response. (auburn.edu)
  • This suggests that MASP-1 has a crucial role in the initiation steps of lectin pathway activation most probably by activating MASP-2. (jimmunol.org)
  • The third SP of the lectin pathway, MASP-3, was recently shown to be the major activator, and the exclusive "resting blood" activator of profactor D, producing factor D, the initiator protease of the alternative pathway. (frontiersin.org)
  • Mannose-binding lectin (MBL) and L-ficolin/P35 are human serum lections that are complexed with MASP. (nii.ac.jp)
  • The unit also includes an MBL/MASP complex activity assay to evaluate MBL activity in serum or plasma samples, which allows for the measurement of the specific activity of the MBL pathway. (currentprotocols.com)
  • I was excited to present narsoplimab data demonstrating that targeted upstream inhibition of the lectin pathway of complement - specifically MASP-2 - is a promising treatment strategy for HSCT-TMA," said Professor Rambaldi. (businesswire.com)
  • MASP-3 is the exclusive pro-factor D activator in resting blood: the lectin and the alternative complement pathways are fundamentally linked , SCIENTIFIC REPORTS 2016: (6) Paper 31877. (doktori.hu)
  • 2009). Clinical significance of complement deficiencies. (sinobiological.com)
  • There are deficiencies of each of the individual components of complement. (primaryimmune.org)
  • Patients with complement deficiencies encounter clinical problems that depend on the role of the specific complement protein in normal function. (primaryimmune.org)
  • The alternative pathway serves as an amplification loop, but it can also be activated on its own by the "tick-over" mechanism ( 5 ). (frontiersin.org)
  • To understand the mechanism of lectin pathway inhibition by E. faecalis, we purified and characterized cell wall carbohydrates of E. faecalis wild type and V583ΔtagB. (sigmaaldrich.com)
  • A revised mechanism for the activation of complement C3 to C3b: a molecular explanation of a disease-associated polymorphism. (ucl.ac.uk)
  • Here we show that resident gut bacteria drive intestinal epithelial expression of a C-type lectin that binds peptidoglycan and has direct antimicrobial activity, revealing a primitive mechanism of lectin-mediated innate immunity. (sciencemag.org)
  • Properdin makes it possible for the amplification loop of the alternative pathway to set up a very efficient mechanism for putting lots of C3b onto the surface of the activating cells, protein complexes or particles in the immediate vicinity of the activation site. (primaryimmune.org)
  • This time-limitation is another control mechanism for the complement pathway. (primaryimmune.org)
  • In these motifs, the residues required for Fg binding are largely conserved, and they therefore constitute variants of a common Fg binding motif which binds to Fg with high affinity. (asm.org)
  • Mannose binding-lectin (MBL) is an important component of innate immunity, and activator of the lectin complement pathway. (ahajournals.org)
  • The affinity of factor B to bind C3b is higher on "activating "surfaces, and the half-life of C3bB, C3Bb, and C3Bb(C3b)n complexes, significantly increased by the action of properdin, allows the alternative pathway amplification loop to be formed. (asmscience.org)
  • The Classical Pathway (CP) is activated primarily by immunoglobulins (antibodies, including autoantibodies) that are bound to antigens - either in the fluid phase as soluble immune complexes, or on cell membrane surfaces or other tissues. (primaryimmune.org)
  • The mannose-binding lectin pathway can be activated by C3 hydrolysis or antigens without the presence of antibodies (non-specific immune response). (technologynetworks.com)
  • Here, using in vitro assays for FVIII endocytosis by human monocyte-derived dendritic cells and presentation to T cells, as well as in vivo complement depletion in FVIII-deficient mice, we show a novel role for complement C3 in enhancing the immune response against therapeutic FVIII. (haematologica.org)
  • The complement pathway plays an essential role in the innate and adaptive immune response. (antikoerper-online.de)
  • The classical complement pathway typically requires antibodies for activation (specific immune response), while the alternative and mannose-binding lectin pathways can be activated by C3 hydrolysis or antigens without the presence of antibodies (non-specific immune response). (wikidoc.org)
  • C2 and C4 also participate in the LP. The LP is thought to be the most evolutionarily primitive of the complement pathways and the first to react before the adaptive immune response occurs. (primaryimmune.org)
  • The strategies used by Enterococcus faecalis to evade recognition by human complement are incompletely understood. (sigmaaldrich.com)
  • The contribution of individual activation pathways to different biological processes can be assessed by using pathway-selective inhibitors. (jimmunol.org)
  • A simplified diagram of the three complement activation pathways: the classical, the lectin pathway, and the alternative pathway. (asmscience.org)
  • The diagram in Figure 1 depicts the activation pathways. (primaryimmune.org)
  • In the early 20th century, this controversy was resolved when it became understood that complement can act in combination with specific antibodies, or on its own in a non-specific way. (wikipedia.org)