DEFENSINS found in azurophilic granules of neutrophils and in the secretory granules of intestinal PANETH CELLS.
Family of antimicrobial peptides that have been identified in humans, animals, and plants. They are thought to play a role in host defenses against infections, inflammation, wound repair, and acquired immunity.
DEFENSINS found mainly in epithelial cells.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins. They displace DIVALENT CATIONS from phosphate groups of MEMBRANE LIPIDS leading to disruption of the membrane.
Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.

Inactivation of the dlt operon in Staphylococcus aureus confers sensitivity to defensins, protegrins, and other antimicrobial peptides. (1/352)

Positively charged antimicrobial peptides with membrane-damaging activity are produced by animals and humans as components of their innate immunity against bacterial infections and also by many bacteria to inhibit competing microorganisms. Staphylococcus aureus and Staphylococcus xylosus, which tolerate high concentrations of several antimicrobial peptides, were mutagenized to identify genes responsible for this insensitivity. Several mutants with increased sensitivity were obtained, which exhibited an altered structure of teichoic acids, major components of the Gram-positive cell wall. The mutant teichoic acids lacked D-alanine, as a result of which the cells carried an increased negative surface charge. The mutant cells bound fewer anionic, but more positively charged proteins. They were sensitive to human defensin HNP1-3, animal-derived protegrins, tachyplesins, and magainin II, and to the bacteria-derived peptides gallidermin and nisin. The mutated genes shared sequence similarity with the dlt genes involved in the transfer of D-alanine into teichoic acids from other Gram-positive bacteria. Wild-type strains bearing additional copies of the dlt operon produced teichoic acids with higher amounts of D-alanine esters, bound cationic proteins less effectively and were less sensitive to antimicrobial peptides. We propose a role of the D-alanine-esterified teichoic acids which occur in many pathogenic bacteria in the protection against human and animal defense systems.  (+info)

In vitro antibacterial activities of platelet microbicidal protein and neutrophil defensin against Staphylococcus aureus are influenced by antibiotics differing in mechanism of action. (2/352)

Thrombin-induced platelet microbicidal protein-1 (tPMP-1) and human neutrophil defensin-1 (HNP-1) are small, cationic antimicrobial peptides. These peptides exert potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus. Evidence suggests that tPMP-1 and HNP-1 target and disrupt the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacterium or whether subsequent, presumably intracellular, events are also involved in killing. We investigated the staphylocidal activities of tPMP-1 and HNP-1 in the presence or absence of pretreatment with antibiotics that differ in their mechanisms of action. The staphylocidal effects of tPMP-1 and HNP-1 on control cells (no antibiotic pretreatment) were rapid and concentration dependent. Pretreatment of S. aureus with either penicillin or vancomycin (bacterial cell wall synthesis inhibitors) significantly enhanced the anti-S. aureus effects of tPMP-1 compared with the effects against the respective control cells over the entire tPMP-1 concentration range tested (P < 0.05). Similarly, S. aureus cells pretreated with these antibiotics were more susceptible to HNP-1 than control cells, although the difference in the effects against cells that received penicillin pretreatment did not reach statistical significance (P < 0.05 for cells that received vancomycin pretreatment versus effects against control cells). Studies with isogenic pairs of strains with normal or deficient autolytic enzyme activities demonstrated that enhancement of S. aureus killing by cationic peptides and cell wall-active agents could not be ascribed to a predominant role of autolytic enzyme activation. Pretreatment of S. aureus cells with tetracycline, a 30S ribosomal subunit inhibitor, significantly decreased the staphylocidal effect of tPMP-1 over a wide peptide concentration range (0.16 to 1.25 microgram/ml) (P < 0.05). Furthermore, pretreatment with novobiocin (an inhibitor of bacterial DNA gyrase subunit B) and with azithromycin, quinupristin, or dalfopristin (50S ribosomal subunit protein synthesis inhibitors) essentially blocked the S. aureus killing resulting from exposure to tPMP-1 or HNP-1 at most concentrations compared with the effects against the respective control cells (P < 0.05 for a tPMP-1 concentration range of 0.31 to 1.25 microgram/ml and for an HNP-1 concentration range of 6.25 to 50 microgram/ml). These findings suggest that tPMP-1 and HNP-1 exert anti-S. aureus activities through mechanisms involving both the cell membrane and intracellular targets.  (+info)

Neutrophil defensins induce histamine secretion from mast cells: mechanisms of action. (3/352)

Defensins are endogenous antimicrobial peptides stored in neutrophil granules. Here we report that a panel of defensins from human, rat, guinea pig, and rabbit neutrophils all have histamine-releasing activity, degranulating rat peritoneal mast cells with EC50 ranging from 70 to 2500 nM, and between 45 and 60% of the total histamine released. The EC50 for defensin-induced histamine secretion correlates with their net basic charge at neutral pH. There is no correlation between histamine release and antimicrobial potency. Degranulation induced by defensins has characteristics similar to those of activation by substance P. The maximum percent histamine release is achieved in <10 s, and it can be markedly inhibited by pertussis toxin (100 ng/ml) and by pretreatment of mast cells with neuraminidase. These properties differ from those for degranulation induced by IgE-dependent Ag stimulation and by the calcium ionophore A23187. GTPase activity, a measure of G protein activation, was induced in a membrane fraction from mast cells following treatment with defensin. Thus, neutrophil defensins are potent mast cell secretagogues that act in a manner similar to substance P and 48/80, through a rapid G protein-dependent response that is mechanistically distinct from Ag/IgE-dependent mast cell activation. Defensins may provide important pathways for communication between neutrophils and mast cells in defenses against microbial agents and in acute inflammatory responses.  (+info)

Isolation, characterization, cDNA cloning, and antimicrobial properties of two distinct subfamilies of alpha-defensins from rhesus macaque leukocytes. (4/352)

Experiments to isolate and characterize rhesus macaque myeloid alpha-defensins (RMADs) were conducted. Seven RMAD peptides were isolated and sequenced, and the cDNAs encoding six of these peptides and one other alpha-defensin from bone marrow were also characterized. Four of the RMADs were found to be highly similar to human neutrophil alpha-defensins HNP-1 to HNP-3, while the remaining four peptides were much more similar to human enteric alpha-defensin HD-5. Two alpha-defensin pairs differed only by the presence or absence of an additional arginine at the amino termini of their mature peptides, indicative of alternate posttranslational processing. The primary translation products of RMAD-1 to -8 are 94- and 96-amino-acid prepropeptides that are highly similar to those of human alpha-defensins. Immunolocalization experiments revealed a granular cytoplasmic pattern in the cytoplasms of neutrophils, indistinguishable from the pattern observed after immunostaining of human myeloid alpha-defensins in polymorphonuclear leukocytes. Each of the purified peptides was tested for its in vitro activities against Staphylococcus aureus 502a, Listeria monocytogenes EGD, Escherichia coli ML35, and Cryptococcus neoformans 271A. Several of the peptides were microbicidal for the gram-positive bacteria and C. neoformans at defensin concentrations in the range of 2 to 5 microM. All of the peptides were bacteriostatic against E. coli, but none were bactericidal for this organism. This study is the first to characterize the sequences and activities of alpha-defensins from nonhuman primates, data that should aid in delineating the role of these peptides in rhesus macaque host defense.  (+info)

Protective immunity against Streptococcus mutans infection in mice after intranasal immunization with the glucan-binding region of S. mutans glucosyltransferase. (5/352)

Here we present the construction and characterization of a chimeric vaccine protein combining the glucan-binding domain (GLU) of the gtfB-encoded water-insoluble glucan-synthesizing glucosyltransferase enzyme (GTF-I) from Streptococcus mutans and thioredoxin from Escherichia coli, which increases the solubility of coexpressed recombinant proteins and stimulates proliferation of murine T cells. The protective potential of intranasal (i.n.) immunization with this chimeric immunogen was compared to that of the GLU polypeptide alone in a mouse infection model. Both immunogens were able to induce statistically significant mucosal (salivary and vaginal) and serum responses (P < 0.01) which were sustained to the end of the study (experimental day 100). Following infection with S. mutans, sham-immunized mice maintained high levels of this cariogenic organism ( approximately 60% of the total oral streptococci) for at least 5 weeks. In contrast, animals immunized with the thioredoxin-GLU chimeric protein (Thio-GLU) showed significant reduction (>85%) in S. mutans colonization after 3 weeks (P < 0.05). The animals immunized with GLU alone required 5 weeks to demonstrate significant reduction (>50%) of S. mutans infection (P < 0.05). Evaluation of dental caries activity at the end of the study showed that mice immunized with either Thio-GLU or GLU had significantly fewer carious lesions in the buccal enamel or dentinal surfaces than the sham-immunized animals (P < 0.01). The protective effects against S. mutans colonization and caries activity following i.n. immunization with GLU or Thio-GLU are attributed to the induced salivary immunoglobulin A (IgA) anti-GLU responses. Although in general Thio-GLU was not significantly better than GLU alone in stimulating salivary IgA responses and in protection against dental caries, the finding that the GLU polypeptide alone, in the absence of any immunoenhancing agents, is protective against disease offers a promising and safe strategy for the development of a vaccine against caries.  (+info)

Imaging of bacterial infections with 99mTc-labeled human neutrophil peptide-1. (6/352)

This study was undertaken to evaluate whether 99mTc-labeled human neutrophil peptide (HNP)-1 can be used as a tracer for rapid visualization of bacterial infections. METHODS: Mice were injected intramuscularly with 1 million Staphylococcus aureus or Klebsiella pneumoniae organisms and 5 min later were injected intravenously with 0.4 microg (0.8 MBq) 99mTc-HNP-1. At various intervals, detailed information about clearance and accumulation of this tracer at sites of infection and in various organs was obtained by scintigraphy. 99mTc-labeled immunoglobulin G (IgG), an established marker of infection and inflammation, was used for comparison. RESULTS: After injection into S. aureus- or K. pneumoniae-injected mice, 99mTC-HNP-1 was rapidly removed from the circulation, mainly through the kidneys and bladder, with half-lives of 170 and 55 min, respectively. Similar half-lives were observed for 99mTc-IgG in these animals. Visualization of foci with S. aureus or K. pneumoniae, as indicated by a ratio of 1.3 or higher between the targeted thigh muscle (containing bacteria) and the nontargeted (contralateral) thigh muscle (T/NT), was already achieved 5 min after injection of 99mTc-HNP-1. Similar T/NTs for 99mTc-IgG were obtained 4 h after injection of the tracer, indicating that imaging of foci of bacteria with 99mTc-HNP-1 is much faster than with 99mTc-IgG. To obtain insight into factors that contribute to accumulation of 99mTc-HNP-1 at sites of infection, the binding of this tracer to bacteria and leukocytes was assessed using a peritoneal infection model. Binding of 99mTC-HNP-1 to bacteria was approximately 1000 times higher than binding to leukocytes. Although the number of bacteria in the peritoneum was 1000-fold lower than the number of leukocytes, a significant correlation between binding of 99mTc-HNP-1 to bacteria on the one hand and accumulation of tracer on the other was still found, in contrast to 99mTc-IgG. CONCLUSION: 99mTc-HNP-1 allows rapid visualization of bacterial infections. Binding of this tracer to bacteria most likely contributes significantly to the accumulation of 99mTc-HNP-1 at sites of infection.  (+info)

Engineered salt-insensitive alpha-defensins with end-to-end circularized structures. (7/352)

We designed a retro-isomer and seven circularized "beta-tile" peptide analogs of a typical rabbit alpha-defensin, NP-1. The analogs retained defensin-like architecture after the characteristic end-to-end, Cys(3,31) (C I:C VI), alpha-defensin disulfide bond was replaced by a backbone peptide bond. The retro-isomer of NP-1 was as active as the parent compound, suggesting that overall topology and amphipathicity governed its antimicrobial activity. A beta-tile design with or without a single cross-bracing disulfide bond sufficed for antimicrobial activity, and some of the analogs retained activity against Escherichia coli and Salmonella typhimurium in NaCl concentrations that rendered NP-1 inactive. The new molecules had clustered positive charges resembling those in protegrins and tachyplesins, but were less cytotoxic. Such simplified alpha-defensin analogs minimize problems encountered during the oxidative folding of three-disulfide defensins. In addition, they are readily accessible to a novel thia zip cyclization procedure applicable to large unprotected peptide precursors of 31 amino acids in aqueous solutions. Collectively, these findings provide new and improved methodology to create salt-insensitive defensin-like peptides for application against bacterial diseases.  (+info)

Role of CCAAT/enhancer-binding protein site in transcription of human neutrophil peptide-1 and -3 defensin genes. (8/352)

The human neutrophil defensins (human neutrophil peptides (HNPs)), major components of azurophilic granules, contribute to innate and acquired host immunities through their potent antimicrobial activities and ability to activate T cells. Despite being encoded by nearly identical genes, HNP-1 is more abundant in the granules than HNP-3. We investigated the regulation of HNP-1 and HNP-3 expression at the transcriptional level using a promyelocytic HL-60 cell line. Luciferase analysis showed that transcriptional levels of HNP-1 and HNP-3 promoters were equivalent and that an approximately 200-bp region identical between promoters was sufficient for transcriptional activity. Furthermore, overlapping CCAAT/enhancer-binding protein (C/EBP) and c-Myb sites in the region were found to be required for efficient transcription. Gel mobility shift assay demonstrated that C/EBPalpha predominantly bound to the C/EBP/c-Myb sites using HL-60 nuclear extracts. No specific binding to C/EBP/c-Myb sites was observed in nuclear extracts from mature neutrophils, which expressed neither C/EBPalpha protein nor HNP mRNAs. Taken together, these findings suggest that the difference in the amounts of HNP-1 and HNP-3 peptides in neutrophils is caused by posttranscriptional regulation and that C/EBPalpha plays an important role in the transcription of HNP genes in immature myeloid cells.  (+info)

Alpha-defensins are a type of defensin, which are small cationic host defense peptides that contribute to the innate immune system's response to microbial invasion. They are primarily produced by neutrophils, but can also be expressed by some epithelial cells and other immune cells. Alpha-defensins have broad-spectrum antimicrobial activity against bacteria, fungi, and enveloped viruses. They also play a role in modulating the inflammatory response and wound healing. There are six human alpha-defensin genes (DEFA1 to DEFA6) that encode six different peptides: Human Neutrophil Peptides 1-4 (HNP1-4) and Human Defensin 5 and 6 (HD5 and HD6). The HNPs are stored in the azurophilic granules of neutrophils and are released upon their activation, while HD5 and HD6 are found in the Paneth cells of the small intestine.

Defensins are small, cationic host defense peptides that contribute to the innate immune system's response against microbial pathogens. They are produced by various cell types, including neutrophils, epithelial cells, and some bone marrow-derived cells. Defensins have a broad spectrum of antimicrobial activity against bacteria, fungi, viruses, and enveloped lipid bilayers.

Defensins are classified into two main groups: α-defensins and β-defensins. Human α-defensins include human neutrophil peptides (HNP) 1-4 and human defensin 5, 6 (HD5, HD6). These are primarily produced by neutrophils and Paneth cells in the small intestine. β-defensins, on the other hand, are produced by various epithelial cells throughout the body.

Defensins work by disrupting the microbial membrane's integrity, leading to cell lysis and death. They also have immunomodulatory functions, such as chemotaxis of immune cells, modulation of cytokine production, and enhancement of adaptive immune responses. Dysregulation of defensin expression has been implicated in several diseases, including inflammatory bowel disease, chronic obstructive pulmonary disease, and certain skin disorders.

Beta-defensins are a group of small, cationic host defense peptides that play an important role in the innate immune system. They have broad-spectrum antimicrobial activity against various pathogens, including bacteria, fungi, and viruses. Beta-defensins are produced by epithelial cells, phagocytes, and other cell types in response to infection or inflammation. They function by disrupting the membranes of microbes, leading to their death. Additionally, beta-defensins can also modulate the immune response by recruiting immune cells to the site of infection and regulating inflammation. Mutations in beta-defensin genes have been associated with increased susceptibility to infectious diseases.

Blood proteins, also known as serum proteins, are a group of complex molecules present in the blood that are essential for various physiological functions. These proteins include albumin, globulins (alpha, beta, and gamma), and fibrinogen. They play crucial roles in maintaining oncotic pressure, transporting hormones, enzymes, vitamins, and minerals, providing immune defense, and contributing to blood clotting.

Albumin is the most abundant protein in the blood, accounting for about 60% of the total protein mass. It functions as a transporter of various substances, such as hormones, fatty acids, and drugs, and helps maintain oncotic pressure, which is essential for fluid balance between the blood vessels and surrounding tissues.

Globulins are divided into three main categories: alpha, beta, and gamma globulins. Alpha and beta globulins consist of transport proteins like lipoproteins, hormone-binding proteins, and enzymes. Gamma globulins, also known as immunoglobulins or antibodies, are essential for the immune system's defense against pathogens.

Fibrinogen is a protein involved in blood clotting. When an injury occurs, fibrinogen is converted into fibrin, which forms a mesh to trap platelets and form a clot, preventing excessive bleeding.

Abnormal levels of these proteins can indicate various medical conditions, such as liver or kidney disease, malnutrition, infections, inflammation, or autoimmune disorders. Blood protein levels are typically measured through laboratory tests like serum protein electrophoresis (SPE) and immunoelectrophoresis (IEP).

Antimicrobial cationic peptides (ACPs) are a group of small, naturally occurring peptides that possess broad-spectrum antimicrobial activity against various microorganisms, including bacteria, fungi, viruses, and parasites. They are called "cationic" because they contain positively charged amino acid residues (such as lysine and arginine), which allow them to interact with and disrupt the negatively charged membranes of microbial cells.

ACPs are produced by a wide range of organisms, including humans, animals, and plants, as part of their innate immune response to infection. They play an important role in protecting the host from invading pathogens by directly killing them or inhibiting their growth.

The antimicrobial activity of ACPs is thought to be mediated by their ability to disrupt the membranes of microbial cells, leading to leakage of cellular contents and death. Some ACPs may also have intracellular targets, such as DNA or protein synthesis, that contribute to their antimicrobial activity.

ACPs are being studied for their potential use as therapeutic agents to treat infectious diseases, particularly those caused by drug-resistant bacteria. However, their clinical application is still in the early stages of development due to concerns about their potential toxicity to host cells and the emergence of resistance mechanisms in microbial pathogens.

Alpha 1-antitrypsin (AAT, or α1-antiproteinase, A1AP) is a protein that is primarily produced by the liver and released into the bloodstream. It belongs to a group of proteins called serine protease inhibitors, which help regulate inflammation and protect tissues from damage caused by enzymes involved in the immune response.

Alpha 1-antitrypsin is particularly important for protecting the lungs from damage caused by neutrophil elastase, an enzyme released by white blood cells called neutrophils during inflammation. In the lungs, AAT binds to and inhibits neutrophil elastase, preventing it from degrading the extracellular matrix and damaging lung tissue.

Deficiency in alpha 1-antitrypsin can lead to chronic obstructive pulmonary disease (COPD) and liver disease. The most common cause of AAT deficiency is a genetic mutation that results in abnormal folding and accumulation of the protein within liver cells, leading to reduced levels of functional AAT in the bloodstream. This condition is called alpha 1-antitrypsin deficiency (AATD) and can be inherited in an autosomal codominant manner. Individuals with severe AATD may require augmentation therapy with intravenous infusions of purified human AAT to help prevent lung damage.

Neutrophils are a type of white blood cell that are part of the immune system's response to infection. They are produced in the bone marrow and released into the bloodstream where they circulate and are able to move quickly to sites of infection or inflammation in the body. Neutrophils are capable of engulfing and destroying bacteria, viruses, and other foreign substances through a process called phagocytosis. They are also involved in the release of inflammatory mediators, which can contribute to tissue damage in some cases. Neutrophils are characterized by the presence of granules in their cytoplasm, which contain enzymes and other proteins that help them carry out their immune functions.

Alpha defensins are a family of mammalian defensin peptides of the alpha subfamily. In mammals they are also known as cryptdins ... Defensin α-defensin β-defensin θ-defensin Cryptdin Hill CP, Yee J, Selsted ME, Eisenberg D (March 1991). "Crystal structure of ... mammalian defensins are classified into alpha, beta and theta categories. Alpha-defensins, which have been identified in humans ... "Interactions of mouse Paneth cell alpha-defensins and alpha-defensin precursors with membranes. Prosegment inhibition of ...
Richardson M, Bloch Jr C (1991). "A new family of small (5 kDa) protein inhibitors of insect alpha-amylases from seeds or ... This superfamily includes arthropod defensins and fungal defensins (but not defensins found in mammals). It also includes ... Plant defensins (formerly gamma-thionins) are a family of small, cysteine-rich defensins found in plants that serve to defend ... Most characterized plant defensins are antimicrobial peptides. Both antifungal and antibacterial plant defensins have been ...
The alpha defensin peptides are increased in chronic inflammatory conditions. Alpha defensin are increased in several cancers, ... Vertebrate defensins are primarily α-defensins and β-defensins. Some primates additionally have the much smaller θ-defensins. ... Only alpha and beta-defensins are expressed in humans. Although the most well-studied defensins are from vertebrates, a family ... A reduction of ileal defensins may predispose to Crohn's disease. In one small study, a significant increase in alpha defensin ...
TNF-alpha, and IL-1beta, but not IL-6, induce human beta-defensin-2 in respiratory epithelia". American Journal of Respiratory ... Beta-defensin 2 is an antibiotic peptide which is locally regulated by inflammation. Human beta-defensin 2 is produced by a ... Defensins form a family of microbicidal and cytotoxic peptides made by neutrophils. Members of the defensin family are highly ... "Entrez Gene: DEFB4 defensin, beta 4". Schröder JM, Harder J (June 1999). "Human beta-defensin-2". The International Journal of ...
Defensin, alpha 1B a human protein that is encoded by the DEFA1B gene. defensin ENSG00000285176 GRCh38: Ensembl release 89: ... "Entrez Gene: defensin". Kocsis AK, Ocsovszky I, Tiszlavicz L, et al. (2009). "Helicobacter pylori induces the release of alpha- ... Aldred PM, Hollox EJ, Armour JA (2005). "Copy number polymorphism and expression level variation of the human alpha-defensin ... PDBe-KB provides an overview of all the structure information available in the PDB for Human Neutrophil defensin 1 (DEFA1B) v t ...
θ-defensins are extremely divergent members of the defensin protein superfamily which includes alpha-, beta- and big-defensins ... Defensin α-defensin β-defensin Cyclic peptide Conibear AC, Craik DJ (26 September 2014). "The chemistry and biology of theta ... The θ-defensins appear to have evolved from α-defensin genes around 40 million years ago in Old World monkeys. Compared to ... Theta-defensins (θ-defensins, retrocyclins, or demidefensins) are a family of mammalian antimicrobial peptides. They are found ...
Defensin, alpha 4 (DEFA4), also known as neutrophil defensin 4 or HNP4, is a human defensin peptide that is encoded by the ... Several human alpha defensin genes including HNP4 are clustered on chromosome 8. DEFA4 differs from other defensin genes by an ... "Entrez Gene: DEFA4; defensin, alpha 4, corticostatin (Homo sapiens)". Wu Z, Ericksen B, Tucker K, Lubkowski J, Lu W (September ... Szyk A, Wu Z, Tucker K, Yang D, Lu W, Lubkowski J (December 2006). "Crystal structures of human alpha-defensins HNP4, HD5, and ...
Defensin, alpha 5 (DEFA5) also known as human alpha defensin 5 (HD5) is a protein that in humans is encoded by the DEFA5 gene. ... "Entrez Gene: DEFA5 defensin, alpha 5, Paneth cell-specific". Jones DE, Bevins CL (January 1993). "Defensin-6 mRNA in human ... Several of the human alpha defensin genes appear to be clustered on chromosome 8. The protein encoded by this gene, α-defensin- ... Szyk A, Wu Z, Tucker K, Yang D, Lu W, Lubkowski J (December 2006). "Crystal structures of human alpha-defensins HNP4, HD5, and ...
Defensin, alpha 1 also known as human alpha defensin 1, human neutrophil peptide 1 (HNP-1) or neutrophil defensin 1 is a human ... Human alpha defensin 1 belongs to the alpha defensin family of antimicrobial peptides. Defensins are a family of microbicidal ... Several alpha defensin genes are clustered on chromosome 8. The protein encoded by this gene, defensin, alpha 1, is found in ... "Entrez Gene: DEFA1 defensin, alpha 1". Valore EV, Ganz T (Mar 15, 1992). "Posttranslational processing of defensins in immature ...
The principal defense molecules secreted by Paneth cells are alpha-defensins, which are known as cryptdins in mice. These ... Ayabe T, Satchell DP, Wilson CL, Parks WC, Selsted ME, Ouellette AJ (August 2000). "Secretion of microbicidal alpha-defensins ... December 2005). "Reduced Paneth cell alpha-defensins in ileal Crohn's disease". Proceedings of the National Academy of Sciences ... Human Paneth cells produce two α-defensins known as human α-defensin HD-5 (DEFA5) and HD-6 (DEFA6). HD-5 has a wide spectrum of ...
Defensin, alpha 6 (DEFA6) also known as human alpha defensin 6 (HD6) is a human protein that is encoded by the DEFA6 gene. ... "Entrez Gene: DEFA6 defensin, alpha 6, Paneth cell-specific (Homo sapiens)". Jones DE, Bevins CL (January 1993). "Defensin-6 ... The alpha defensins are a family of microbicidal and cytotoxic peptides that defend the host against bacteria and viruses. HD6 ... Szyk A, Wu Z, Tucker K, Yang D, Lu W, Lubkowski J (December 2006). "Crystal structures of human alpha-defensins HNP4, HD5, and ...
The fact that alpha and theta defensins are absence in older vertebrates, like birds and fishes, indicates that defensins must ... α-defensins and insect defensins. Subsequent structural analyses have suggested that the β-defensins, α-defensins, θ-defensins ... Defensin α-defensin β-defensin θ-defensin Lingual antimicrobial peptide White SH, Wimley WC, Selsted ME (August 1995). " ... Liu L, Zhao C, Heng HH, Ganz T (August 1997). "The human beta-defensin-1 and alpha-defensins are encoded by adjacent genes: two ...
... alpha-defensins, beta-defensins and theta-defensins. All beta-defensin genes are densely clustered in four to five syntenic ... Beta-defensin 106 is a protein that in humans is encoded by the DEFB106A gene. Defensins form a family of microbicidal and ... "Entrez Gene: DEFB106A defensin, beta 106A". Xin A (Jan 2014). "Soluble fusion expression, characterization and localization of ... Kao CY, Chen Y, Zhao YH, Wu R (2003). "ORFeome-based search of airway epithelial cell-specific novel human [beta]-defensin ...
... alpha-defensins, beta-defensins and theta-defensins. All beta-defensin genes are densely clustered in four to five syntenic ... Beta-defensin 104 is a protein that in humans is encoded by the DEFB104A gene. Defensins form a family of microbicidal and ... "Entrez Gene: DEFB104A defensin, beta 104A". Patil AA, Cai Y, Sang Y, Blecha F, Zhang G (September 2005). "Cross-species ... Boniotto M, Ventura M, Eskdale J, Crovella S, Gallagher G (2005). "Evidence for duplication of the human defensin gene DEFB4 in ...
Alpha defensins, Beta defensins and Theta defensins. All beta-defensin genes are densely clustered in four to five syntenic ... Beta-defensin 105 is a protein that is encoded by the DEFB105A gene in humans. Defensins form a family of microbicidal and ... "Entrez Gene: DEFB105A defensin, beta 105A". Patil AA, Cai Y, Sang Y, et al. (2006). "Cross-species analysis of the mammalian ... Semple CA, Rolfe M, Dorin JR (May 2003). "Duplication and selection in the evolution of primate beta-defensin genes". Genome ...
Four human alpha defensins are found in the granules of the neutrophil, and these are known as human neutrophil peptides (HNP) ... Xie C, Zeng P, Ericksen B, Wu Z, Lu WY, Lu W (2005). "Effects of the terminal charges in human neutrophil alpha-defensin 2 on ... Wu Z, Li X, de Leeuw E, Ericksen B, Lu W (2005). "Why is the Arg5-Glu13 salt bridge conserved in mammalian alpha-defensins?". J ... The initial virtual colony count study measured the activity of all six human alpha defensins concurrently on the same 96-well ...
Paneth cells produce antimicrobial peptides such as human alpha-defensin. Microfold cells (commonly referred to as M cells) ...
Liu L, Zhao C, Heng HH, Ganz T (August 1997). "The human beta-defensin-1 and alpha-defensins are encoded by adjacent genes: two ... This gene maps in close proximity to defensin family member defensin, alpha 1, and has been implicated in the pathogenesis of ... Beta-defensin 1 is a protein that in humans is encoded by the DEFB1 gene. Defensins form a family of microbicidal and cytotoxic ... Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 1, an antimicrobial ...
Defensin, alpha 3 (DEFA3) also known as human alpha defensin 3, human neutrophil peptide 3 (HNP-3) or neutrophil defensin 3 is ... Human alpha defensin 3 belongs to the alpha defensin family of antimicrobial peptides. Defensins are a family of microbicidal ... Several alpha defensin genes are clustered on chromosome 8. The protein encoded by this gene, defensin, alpha 3, is found in ... Several alpha defensin genes are clustered on chromosome 8. This peptide differs from defensin, alpha 1 by only one amino acid ...
Tanaka S, Edberg JC, Chatham W, Fassina G, Kimberly RP (Dec 2003). "Fc gamma RIIIb allele-sensitive release of alpha-defensins ...
... interacts with human alpha defensins, a class of antimicrobial peptides, such as Defensin, alpha 1. The latter has ... including the common food preservative nisin Teixobactin Copsin Human alpha defensins The D-Ala-D-Ala terminus is used by ... 2013). "Turning defense into offense: defensin mimetics as novel antibiotics targeting lipid II". PLOS Pathog. 9 (11): e1003732 ...
"The human antimicrobial and chemotactic peptides LL-37 and alpha-defensins are expressed by specific lymphocyte and monocyte ... The AMP family also includes the defensins. Whilst the defensins share common structural features, cathelicidin-related ... "Cathelicidin family of antibacterial peptides CAP18 and CAP11 inhibit the expression of TNF-alpha by blocking the binding of ... "Epithelial cell-derived antibacterial peptides human beta-defensins and cathelicidin: multifunctional activities on mast cells ...
Alpha- and beta- thionins are related to each other. The gamma thionins have a superficially similar structure but are an ... unrelated class of protein, now called plant defensins. The proteins are toxic to animal cells, presumably attacking the cell ...
Cutler CW, Jotwani R (April 2006). "Oral mucosal expression of HIV-1 receptors, co-receptors, and alpha-defensins: tableau of ... Whiteheart SW, Shenbagamurthi P, Chen L, Cotter RJ, Hart GW (August 1989). "Murine elongation factor 1 alpha (EF-1 alpha) is ... Brands JH, Maassen JA, van Hemert FJ, Amons R, Möller W (February 1986). "The primary structure of the alpha subunit of human ... Addition of ethanolamine-phosphoglycerol to specific glutamic acid residues on EF-1 alpha". The Journal of Biological Chemistry ...
... is homologous with other venom myotoxins and is similar to α-,β-defensins. The amino acid sequence ( ... the protein is composed of a short N-terminal alpha helix, a type of protein formation, and a small antiparallel triple- ... Crotamine has similar structural fold conformations to the human b-defensin family as well as identical disulfide bridges ...
... deacetylates the estrogen receptor alpha and p53 and inhibits their transactivation functions. MTA2 represses the ... The expression of MTA2 is inhibited by the Rho GDIa in breast cancer cells and by human β-defensins in colon cancer cells. ... "Human β-defensin-3 inhibits migration of colon cancer cells via downregulation of metastasis-associated 1 family, member 2 ... "Metastasis-associated protein 2 is a repressor of estrogen receptor alpha whose overexpression leads to estrogen-independent ...
2004). "Calcium triggers beta-defensin (hBD-2 and hBD-3) and chemokine macrophage inflammatory protein-3 alpha (MIP-3alpha/ ... Beta-defensin 103 is a protein that in humans is encoded by the DEFB103A gene. Defensins form a family of microbicidal and ... Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 103B, which has broad ... 2002). "Identification of a novel, multifunctional beta-defensin (human beta-defensin 3) with specific antimicrobial activity. ...
It is a G5 star located at (J2000.0; 00h 05m 10.1829s; +02° 23′ 49.949″) Human Alpha Defensin 5, the DEFA5 gene product This ...
... avian defensins) and mammals (e.g. cathelicidins, alpha- and beta-defensins, regIII peptides) Research has increased in recent ... "Structure-function analysis of Avian β-defensin-6 and β-defensin-12: role of charge and disulfide bridges". BMC Microbiology. ... Human defensins have been thought to act through a similar mechanism, targeting cell membrane lipids as part of their function ... In more recent years, X-ray crystallography has been used to delineate in atomic detail how the family of plant defensins ...
... a political alliance in the Philippines Human neutrophil peptides or alpha defensins 1-4 This disambiguation page lists ...
  • Alpha defensins are a family of mammalian defensin peptides of the alpha subfamily. (
  • Defensins are 2-6 kDa, cationic, microbicidal peptides active against many Gram-negative and Gram-positive bacteria, fungi, and enveloped viruses, containing three pairs of intramolecular disulfide bonds. (
  • Like other alpha-defensins, cryptdins are small, 32-36 amino acid long cationic peptides. (
  • Initially human alpha defensin peptides were isolated from the neutrophils and are thus called human neutrophil peptides. (
  • Human neutrophil peptides are also known as α-defensins. (
  • Defensins are a family of antimicrobial and cytotoxic peptides thought to be involved in host defense. (
  • Defensins are a large family of peptides of which two groups exist in mammals: alpha defensins and beta defensins - which are distinguishable by the spacing and connectivity of the conserved cysteine residues within the mature peptides. (
  • Z200289Defensins are a large family of peptides of which two groups exist in mammals: alpha defensins and beta defensins - which are distinguishable. (
  • Human beta-defensins represent a family of antimicrobial peptides differentially expressed in most tissues, regulated by specific mechanisms, and exerting physiological functions not only related to direct host defense. (
  • GENTAUR supplies anti-defensins, monclonals, polyclonals antisera and recombinant DEFs or peptides of defensin. (
  • Sequences of major human α-defensins: Genes encoding cryptdins are located on the proximal arm of mouse chromosome 8. (
  • They are similar to other enteric alpha-defensins genes in that they involve a two exon structure. (
  • Two gene knock down methods - dominant negative (DN) plasmid and small interfering RNA (siRNA) - were employed to detect and confirm the involvement of several key genes in the signaling cascade resulting from the NTHi stimulated β-defensin 2 expression in human middle ear epithelial cell (HMEEC-1). (
  • It is thought that the function of defensins in the eradication of pathogens from the host system is to insert themselves into the bacterial membrane under the influence of membrane potential, in doing so forming channels which lead to leakage of cytoplasmic molecules and cell death. (
  • Defensins are produced constitutively and/or in response to microbial products or proinflammatory cytokines. (
  • Among the AIIMs, human β-defensin 2 is the most potent molecule and is inducible by exposure to inflammatory stimuli such as bacterial components or proinflammatory cytokines. (
  • You need info about Human Defensin,alpha 1 (DEFA1) ELISA Kit or any other Gentaur produtct? (
  • human, mouse or other beta β- and alpha α- defensins are expressed by neutrophils ( α- ), lymphocytes and epithelial cells. (
  • Some of the major roles defensins play in host defense are direct antimicrobial activity, facilitation and amplification of innate and adaptive immunity [ 19 - 22 ]. (
  • Scholars@Duke publication: Identification of a novel, multifunctional beta-defensin (human beta-defensin 3) with specific antimicrobial activity. (
  • Unlike hBD-1, this second peptide, human beta-defensin-2 (hBD-2), is regulated at a transcriptional level in response to contact with microorganisms, and is highly effective in killing the gram negative bacteria Its expression is also upregulated by the cytokine tumor necrosis factor-alpha. (
  • Human neutrophil-derived alpha-defensins (HNPs) are capable of enhancing phagocytosis by mouse macrophages. (
  • See the reference protein sequence for neutrophil defensin 1 preproprotein (NP_004075.1). (
  • Recombinant Mouse beta Defensin-2 was lyophilized from 0.2 μm filtered 100 mM NaCl, 20 mM PB, pH 7.4. (
  • Alpha-defensins, which have been identified in humans, monkeys and several rodent species, are particularly abundant in neutrophils, certain macrophage populations and Paneth cells of the small intestine. (
  • Pro-defensin alpha 5 is stored in the granules of Paneth cells in the small intestine (Porter et al. (
  • The mechanism(s) by which microorganisms are killed and/or inactivated by defensins is not understood completely. (
  • In contrast to hBD-2, which is upregulated by microorganisms or tumor necrosis factor-alpha (TNF-alpha), hBD-3 expression is increased particularly after stimulation by interferon-gamma. (
  • They possess 6 conserved cysteines that form a tridisulfide array with an arrangement of cysteine pairings that typify alpha-defensins. (
  • Previous studies have shown the implication of beta-defensins in host defense of the human body. (
  • The human beta-defensins 1 and 2 (hBD-1, hBD-2) have been isolated by biochemical methods. (
  • We believe that this report is the first attempt to elucidate NTHi induced β-defensin expression in airway mucosa, which includes the middle ear. (
  • In combination with our previous studies showing that IL-1α-induced β-defensin 2 expression takes place through a MyD88-independent Raf-MEK1/2-ERK MAPK pathway, we found that both signaling cascades act synergistically to up-regulate β-defensin 2 levels. (
  • Alpha Defensin-1 Biomarker Outperforms Culture in Diagnosing Breast Implant-Related Infection: Results from a Multicenter Prospective Study. (
  • On the basis of their size and pattern of disulfide bonding, mammalian defensins are classified into alpha, beta and theta categories. (
  • We were also asked to include any clinical and cost-effectiveness evidence relating to the Synovasure® alpha defensin tests alone for the diagnosis of PJI. (
  • Furthermore, recognition of NTHi component(s)/ligand(s) by TLR2, activated the Toll/IL-1 receptor (TIR)-MyD88-IRAK1-TRAF6-MKK3/6-p38 MAPK signal transduction pathway, ultimately leading to the induction of β-defensin 2. (
  • The bundle reflects updated diagnostic criteria, which were proposed at the International Consensus Meeting on orthopaedic infections (ICM 2018), and includes the laboratory-based Synovasure® alpha defensin test. (
  • Alpha defensins of the mouse bowel were historically called cryptdins when first discovered. (
  • The polar topology of defensins, with spatially separated charged and hydrophobic regions, allows them to insert themselves into the phospholipid membranes so that their hydrophobic regions are buried within the lipid membrane interior and their charged (mostly cationic) regions interact with anionic phospholipid head groups and water. (
  • This study found that the induction of β-defensin 2 is highest in whole cell lysate (WCL) preparations of NTHi, suggesting that the ligand(s) responsible for this up-regulation may be soluble macromolecule(s). (
  • Here we report the identification of a novel mouse gene, Defb2, which shows sequence similarity to previously described mouse and human airway beta defensins. (
  • The β-defensin proteins are expressed as the C-terminal portion of precursors, and are released by proteolytic cleavage of a signal sequence and, in some cases, a propeptide sequence. (
  • Cross-species analysis of the mammalian beta-defensin gene family: presence of syntenic gene clusters and preferential expression in the male reproductive tract. (
  • The objective of this study was to investigate the role of alpha-defensin in bladder cancer. (
  • A study was undertaken to investigate the role of α-defensins in the pathogenesis of IPF. (
  • The induced expression of this gene by an inflammatory stimulus strongly suggests that this defensin contributes to host defence at the mucosal surface of the airways. (
  • Discovery of five conserved beta -defensin gene clusters using a computational search strategy. (
  • 2. Intestinal defensin gene expression in human populations. (
  • 14. Reduced gene expression of intestinal alpha-defensins predicts diarrhea in a cohort of African adults. (
  • Alpha-defensin DEFA1A3 gene copy number elevation in Danish Crohn's disease patients. (
  • 16. Defensins and mucosal protection. (
  • 6. Expression of human alpha-defensin 5 (HD5) mRNA in nasal and bronchial epithelial cells. (
  • 15. Widespread expression of beta-defensin hBD-1 in human secretory glands and epithelial cells. (
  • human, mouse or other beta β- and alpha α- defensins are expressed by neutrophils ( α- ), lymphocytes and epithelial cells. (
  • 4. Intestinal alpha-defensin expression in pediatric inflammatory bowel disease. (
  • 8. Differential effects of Staphylococcal enterotoxin B-mediated immune activation on intestinal defensins. (
  • DEFENSINS found in azurophilic granules of neutrophils and in the secretory granules of intestinal PANETH CELLS . (
  • 7. Defensin expression in chronic pouchitis in patients with ulcerative colitis or familial adenomatous polyposis coli. (
  • These data are consistent with a role for alpha-defensin in bladder cancer via modulation of cell motility and invasiveness using common intracellular signals, such as Ca2+. (
  • 3. Modulation of host antimicrobial peptide (beta-defensins 1 and 2) expression during gastritis. (
  • The concentrations of α-defensins in plasma, but not in BAL fluid, were significantly higher in IPF patients than in controls. (
  • BAL fluid concentrations of interleukin (IL)-8 in patients with IPF, which were significantly higher than in controls, correlated with those of α-defensins. (
  • Alpha-defensin (alpha-defensin) has been identified as a potential marker for bladder cancer in urine by surface enhanced laser desorption ionization studies, and confirmed using both immunoabsorption and immunodepletion studies. (
  • Surface enhanced laser desorption ionization analysis showed the presence of alpha-defensin in the T24 and A498 cancer cell lines. (
  • It is a beneficial treatment for about 30% of patients with well-compensated chronic hepatitis C. Biochemical responses [defined as normalisation of serum alanine aminotransferase (ALT) levels] are achieved in 37 to 76% of patients at the end of treatment with interferon-alpha-2a at dosages of 3 to 6MU 3 times weekly (given intramuscularly or subcutaneously) for 6 to 12 months. (
  • The long term efficacy of interferon-alpha-2a in patients with chronic hepatitis C is improved by the concomitant administration of ribavirin. (
  • Interferon-alpha-2a shows efficacy similar to that of interferon-alpha-2b or interferon-alpha-n1 in patients with chronic hepatitis C. During the first few days of therapy with interferon-alpha-2a (or other forms of interferon-alpha), most patients experience a transient 'influenza-like' reaction, characterised by fatigue, fever, chills and headache. (
  • Age-Repair Defensins™ are an age-correcting discovery, transported in a special liposome system. (
  • During the course of their research, scientists made an extraordinary discovery: two members of the defensin family have surprising benefits for aging skin in cosmeceutical skincare. (
  • These findings suggest that α-defensins play an important role in the pathogenesis of IPF, and that the plasma α-defensin level may be a useful marker of disease severity and activity. (
  • We propose that autocrine tumor expression of alpha-defensins may play an important role in facilitating the invasive phenotype of bladder cancer in patients. (
  • An inverse relationship was seen between plasma α-defensin levels and the arterial oxygen tension (Pa o 2 ) and pulmonary function (vital capacity (%VC), forced expiratory volume in 1 second (FEV 1 ), and carbon monoxide transfer factor (%T lco )) in patients with IPF. (
  • Plasma levels of α-defensins also correlated with the clinical course in IPF patients with an acute exacerbation. (
  • Improvements in liver histology in patients receiving interferon-alpha-2a are associated with complete biochemical responses to the drug. (
  • Virological responses (defined as an absence of hepatitis C-RNA in the serum) occur in up to 86% of patients after treatment with interferon-alpha-2a 3 to 6MU 3 times weekly for 12 months. (
  • It is noteworthy that expression of alpha-defensins increased with tumor invasiveness. (
  • 11. Oesophageal defensin expression during Candida infection and reflux disease. (
  • LC-MS/MS analysis of whole GCF showed that the level of alpha-defensin 1 (DEFA-1) was higher in periodontitis GCF than in healthy GCF. (
  • Alpha-defensin 5 communicates specifically with skin's Master Stem Cells to unlock the skin's age-corrective potential. (
  • These cell lines show higher classically aggressive in vitro characteristics compared with the J82 cells that did not express alpha-defensin. (
  • After cessation of interferon-alpha-2a therapy, a considerable proportion of treatment responders experience disease reactivation. (
  • β-defensins contain a six-cysteine motif that forms three intra-molecular disulfide bonds. (