Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P81534 (hBD-3)
 230 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The growing public health problem of infections caused by multiresistant Gram-positive bacteria, in particular Staphylococcus aureus, prompted us to screen human epithelia for endogenous S. aureus-killing factors. A novel 5-kDa, nonhemolytic antimicrobial peptide (human beta-defensin-3, hBD-3) was isolated from human lesional psoriatic scales and cloned from keratinocytes. hBD-3 demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes including multiresistant S. aureus and vancomycin-resistant Enterococcus faecium. Ultrastructural analyses of hBD-3-treated S. aureus revealed signs of cell wall perforation. Recombinant hBD-3 (expressed as a His-Tag-fusion protein in Escherichia coli) and chemically synthesized hBD-3 were indistinguishable from naturally occurring peptide with respect to their antimicrobial activity and biochemical properties. Investigation of different tissues revealed skin and tonsils to be major hBD-3 mRNA-expressing tissues. Molecular cloning and biochemical analyses of antimicrobial peptides in cell culture supernatants revealed keratinocytes and airway epithelial cells as cellular sources of hBD-3. Tumor necrosis factor alpha and contact with bacteria were found to induce hBD-3 mRNA expression. hBD-3 therefore might be important in the innate epithelial defense of infections by various microorganisms seen in skin and lung, such as cystic fibrosis.
 ...
PMID:Isolation and characterization of human beta -defensin-3, a novel human inducible peptide antibiotic. 1108 90

Helicobacter pylori strains show both geographic and disease-associated allelic variation. We investigated the diversity present in two genes, babA and babB, which are members of a paralogous family of outer membrane proteins. Eleven family members within a single H. pylori strain, predicted to encode proteins with substantial N- and C-terminal similarity to each other, were classified as babA paralogues. In their central regions, most are less than 54% related to one another. Examining the babA and babB central regions in 42 H. pylori strains from different geographic locales, we identified five different allele groups of babA (AD1 to AD5) and three different allele groups of babB (BD1 to BD3). Phylogenetic analysis revealed that the allelic groupings of babA and babB are independent of one another and that, for both, geographic variation is present. Analysis of synonymous and nonsynonymous substitutions in these regions showed that babA is more diverse, implying an earlier origin than that of the same region of babB, but that the babA diversity region may have more functional constraints. Although recombination has been central to the evolution of both genes, with babA and babB showing low mean compatibility scores and homoplasy ratios of 0.71 and 0.67, respectively, recombination is not sufficient to obscure evidence of clonal descent. Despite the involvement of babA in binding to the host blood group antigen Lewis B, neither the presence of different babA allele groups nor that of different babB allele groups is a determining factor in Lewis B binding of H. pylori strains.
 ...
PMID:Allelic Variation within Helicobacter pylori babA and babB. 1116 14

Intensive use of corticosteroids may be accompanied by increased susceptibility to infections; hence, we investigated the effects of dexamethasone on the expression of antimicrobial peptides, termed human beta-defensins (hBD), by cultured bronchial epithelial cells and mononuclear phagocytes. The results revealed that dexamethasone inhibited the (stimulated) expression of mRNA for hBD-3, but not hBD-1 and hBD-2 by these epithelial cells. Dexamethasone did not affect the (stimulated) mRNA expression of hBD-1 and hBD-2 by mononuclear phagocytes, whereas these cells did not express hBD-3 mRNA.
 ...
PMID:Inhibition of hBD-3, but not hBD-1 and hBD-2, mRNA expression by corticosteroids. 1116 49

Defensins comprise a family of cationic antimicrobial peptides that is characterized by the conserved 6 cysteine residues. They are expressed in the epithelial cells of various organs and are identified as key elements in the host defense system at the mucosal surface. We isolated a novel mouse beta-defensin gene from the bacterial artificial chromosome DNA containing the mouse beta-defensin-3 gene. The full-length cDNA was cloned from skeletal muscle cDNA and called mouse beta-defensin-6 (mBD-6). The predicted peptide conserved the 6-cysteine motif and had 59% amino acid sequence identity with mouse beta-defensin-3 and 59% identity with mouse beta-defensin-4. We demonstrated the expression of mBD-6 in skeletal muscle in addition to the esophagus, tongue, and trachea. In animal models of endotoxemia, mBD-6 expression was also induced in the lung. mBD-6 showed potent antimicrobial activity against Escherichia coli and would play an important role in host defense in the esophagus, airways, and skeletal muscle. mBD-6 is the first reported beta-defensin predominantly expressed in skeletal muscle. This unique tissue specificity suggests some novel physiological roles of this peptide family.
 ...
PMID:A novel mouse beta-defensin, mBD-6, predominantly expressed in skeletal muscle. 1140 84

Antimicrobial peptides, including beta-defensins, are thought to be effective agents against opportunistic infections. In humans, three beta-defensins have been identified. The first human beta-defensin, hBD-1, is predominantly expressed in epithelia of the urogenital tract and has been reported to be constitutive. The second and third human beta-defensins, hBD-2 and hBD-3, were isolated from psoriatic skin and found to be predominantly expressed in skin and respiratory tract. Of note, the hBD-2 gene expression is inducible by various proinflammatory agents such as TNF-alpha, IL-1 beta, IL-8, LPS, bacteria, and yeasts. It has been shown that LPS-induced expression of hBD-2 in human tracheobronchial epithelial cells requires CD14, which may complex with Toll-like receptors (TLRs) to ultimately activate NF-kappa B. In addition, beta-defensins have been recently reported to promote immune responses by recruiting dendritic and T cells. Defensins may play a key role in the mechanism of host defense and innate immunity. These defensins, including hBD-2, might provide a new therapeutic approach to infectious diseases.
 ...
PMID:[Defensins as a mechanism of host defense and innate immunity]. 1152 42

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. Here we report the identification of a third human beta-defensin, called human beta-defensin 3 (hBD-3; cDNA sequence, Genbank accession no. AF295370), based on bioinformatics and functional genomic analysis. Expression of hBD-3 is detected throughout epithelia of many organs and in non-epithelial tissues. 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. Synthetic hBD-3 exhibits a strong antimicrobial activity against gram-negative and gram-positive bacteria and fungi, including Burkholderia cepacia. In addition, hBD-3 activates monocytes and elicits ion channel activity in biomembranes, specifically in oocytes of Xenopus laevis. This paper also shows that screening of genomic sequences is a valuable tool with which to identify novel regulatory peptides. 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.
 ...
PMID:Identification of a novel, multifunctional beta-defensin (human beta-defensin 3) with specific antimicrobial activity. Its interaction with plasma membranes of Xenopus oocytes and the induction of macrophage chemoattraction. 1170 37

The purpose of this study was to investigate the expression of human beta-defensins (hBD), especially of the recently discovered hBD-3, in oral tissues by reverse-transcription polymerase chain reaction (RT-PCR). Primary oral keratinocytes (n = 3) and fibroblasts (n = 3), 64 non-inflamed and 40 inflamed oral tissue samples, and 10 samples of salivary glands, were examined. The transcripts for hBD-3 (61/64), as well as for hBD-1 (64/64) and hBD-2 (54/64), were found to be widely expressed in non-inflamed oral tissues. In contrast, only 23, 22 and 24 of the 40 inflamed tissues showed detectable hBD-1, -2 and -3 transcripts, respectively. In salivary glands, mRNA expression was constitutive for hBD-1, frequent for hBD-2 (9/10), and infrequent for hBD-3 (4/10). Oral keratinocytes, but not fibroblasts, contained transcripts for all beta-defensins, suggesting that the novel hBD-3 is also produced in the epithelial compartment of oral tissues. The results indicate an important role for the novel hBD-3, as well as for hBD-1 and hBD-2, in the innate oral epithelial host defense.
 ...
PMID:The novel human beta-defensin-3 is widely expressed in oral tissues. 1201 54

Beta-defensins are cationic peptides produced by epithelial cells that have been proposed to be an important component of immune function at mucosal surfaces. Similarities between mammalian beta-defensins may permit the use of murine models to further define the role of these peptides in innate host defense. Murine beta-defensin-3 (mBD-3) is a peptide that exhibits homology at the gene level to human beta-defensin-2 (hBD-2), one of four beta-defensins identified in man. The purpose of this study was to determine the antimicrobial activity of mBD-3, the tissue distribution of mBD-3 expression, and the effect of gram-negative bacterial infection on mBD-3 expression. Based on the sequence deduced from mBD-3 cDNA, a 40-amino acid peptide was assembled using automated [n-(9-fluorenyl)methoxycarbonyl] solid-phase synthesis. The antimicrobial activity of synthetic mBD-3 was evaluated in microdilution broth assays using bacterial and fungal organisms. mBD-3 mRNA expression was assayed by polymerase chain reaction (PCR) using cDNA derived from a panel of tissues. Expression of mBD-3 was also evaluated in tissues obtained from mice 24 h after intraperitoneal infection with Escherichia coli using reverse transcriptase (RT)-PCR. Synthetic mBD-3 inhibited the growth of E. coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans at concentrations from 25 to 50 microg/mL. Constitutive expression of mBD-3 mRNA was not consistently found in any organ using RT-PCR. In an E. coli peritonitis model, expression of mBD-3 mRNA was upregulated only in the esophagus and tongue. We conclude that mBD-3 is an inducible peptide with limited tissue expression during E. coli peritonitis. Because it exhibits broad-spectrum antimicrobial activity, this peptide may serve as an innate defense against microbial invasion at specific mucosal surfaces in the mouse.
 ...
PMID:Murine beta-defensin-3 is an inducible peptide with limited tissue expression and broad-spectrum antimicrobial activity. 1241 27

A strain of infectious bursal disease virus (IBDV) was detected from bursal tissues of chicks which suffered from infectious bursal disease (IBD) in Chinju, Korea and provisionally named as Chinju strain. A full-length cDNA clone for segment A gene of the virus was constructed, and complete nucleotide sequence of the gene including noncoding region was determined and analyzed by comparison with that of other IBDV strains. The segment A gene of Chinju strain consisted of 3,269 nucleotides including 862 adenine (26.4%), 917 cytosine (28.0%), 854 guanine (26.1%) and 636 thymine (19.5%). There were regions for two open reading frames (ORFs), ORF1 encoding the VP5 with ATG codon at nucleotides 98-100 and ORF2 encoding the polyprotein of VP2, VP4 and VP3 in the nucleotides 132-3,170. In deduced translation the ORF2 encoded 1,012 amino acids. The full nucleotide sequence of segment A gene and amino acid sequence of ORF2 of the Chinju strain showed 98-99% homology with those of the very virulent IBDVs (vvIBDVs) such as HK46, OKYM, UK661, UPM97/ 61, D6948 and BD3/99. In phylogenetic analysis of nucleotide and amino acid sequences, the Chinju strain was also related closely to the vvIBDVs. Hence, it was suggested that the Chinju strain is a vvIBDV. The nucleotide and amino acid sequences of the Chinju strain with pertinent information can be useful for the development of genetically engineered vaccines and diagnostic reagents against vvIBDV.
 ...
PMID:Cloning and nucleotide analysis of segment A gene of infectious bursal disease virus detected in Korea. 1268 Jun 97

The bactericidal activity of the novel beta-defensin hBD-3 against 28 species and 55 strains of gram-positive cocci and gram-negative fermentative and nonfermentative rods was tested. All strains proved to be highly or intermediately susceptible to hBD-3 (minimal bactericidal concentration [MBC], </=50 micro g/ml), except for Burkholderia cepacia, for all 23 tested strains of which MBCs were >100 micro g/ml.
 ...
PMID:Burkholderia is highly resistant to human Beta-defensin 3. 1270 50


1 2 3 4 5 6 7 8 9 10 Next >>