GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 59, No. 7 ( 2015-07), p. 3808-3815
    Abstract: Pseudomonas aeruginosa Liverpool epidemic strain (LES) infections in cystic fibrosis (CF) patients are associated with transmissibility and increased patient morbidity. This study was designed to assess the in vitro activities of cathelicidin LL-37 peptide (LL-37) and select cationic lipids against Pseudomonas aeruginosa LESB58 in CF sputum and in a setting mimicking the CF airway. We found that LL-37 naturally present in airway surface fluid and some nonpeptide cationic lipid molecules such as CSA-13, CSA-90, CSA-131, and D2S have significant, but broadly differing, bactericidal activities against P. aeruginosa LESB58. We observed strong inhibition of LL-37 bactericidal activity in the presence of purified bacteriophage Pf1, which is highly expressed by P. aeruginosa LES, but the activities of the cationic lipids CSA-13 and CSA-131 were not affected by this polyanionic virus. Additionally, CSA-13 and CSA-131 effectively prevent LESB58 biofilm formation, which is stimulated by Pf1 bacteriophage, DNA, or F-actin. CSA-13 and CSA-131 display strong antibacterial activities against different clinical strains of P. aeruginosa , and their activities against P. aeruginosa LESB58 and Xen5 strains were maintained in CF sputum. These data indicate that synthetic cationic lipids (mimics of natural antimicrobial peptides) are suitable for developing an effective treatment against CF lung P. aeruginosa infections, including those caused by LES strains.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2015
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 187, No. 12 ( 2011-12-15), p. 6402-6409
    Abstract: In addition to its antibacterial activity, the cathelicidin-derived LL-37 peptide induces multiple immunomodulatory effects on host cells. Atomic force microscopy, F-actin staining with phalloidin, passage of FITC-conjugated dextran through a monolayer of lung epithelial cells, and assessment of bacterial outgrowth from cells subjected to Pseudomonas aeruginosa infection were used to determine LL-37’s effect on epithelial cell mechanical properties, permeability, and bacteria uptake. A concentration-dependent increase in stiffness and F-actin content in the cortical region of A549 cells and primary human lung epithelial cells was observed after treatment with LL-37 (0.5–5 μM), sphingosine 1-phosphate (1 μM), or LPS (1 μg/ml) or infection with PAO1 bacteria. Other cationic peptides, such as RK-31, KR-20, or WLBU2, and the antibacterial cationic steroid CSA-13 did not reproduce the effect of LL-37. A549 cell pretreatment with WRW4, an antagonist of the transmembrane formyl peptide receptor-like 1 protein attenuated LL-37’s ability to increase cell stiffness. The LL-37–mediated increase in cell stiffness was accompanied by a decrease in permeability and P. aeruginosa uptake by a confluent monolayer of polarized normal human bronchial epithelial cells. These results suggested that the antibacterial effect of LL-37 involves an LL-37–dependent increase in cell stiffness that prevents epithelial invasion by bacteria.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2011
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    American Society for Microbiology ; 2015
    In:  Antimicrobial Agents and Chemotherapy Vol. 59, No. 10 ( 2015-10), p. 6274-6282
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 59, No. 10 ( 2015-10), p. 6274-6282
    Abstract: Ceragenins constitute a novel family of cationic antibiotics characterized by a broad spectrum of antimicrobial activities, which have mostly been assessed in vitro . Using a polarized human lung epithelial cell culture system, we evaluated the antibacterial activities of the ceragenin CSA-13 against two strains of Pseudomonas aeruginosa (PAO1 and Xen5). Additionally, the biodistribution and bactericidal activity of a CSA-13–IRDye 800CW derivate were assessed using an animal model of peritoneal infection after PAO1 challenge. In cell culture, CSA-13 bactericidal activities against PAO1 and Xen5 were higher than the activities of the human cathelicidin peptide LL-37. Increased CSA-13 activity was observed in polarized human lung epithelial cell cultures subjected to butyric acid treatment, which is known to increase endogenous LL-37 production. Eight hours after intravenous or intraperitoneal injection, the greatest CSA-13–IRDye 800CW accumulation was observed in mouse liver and kidneys. CSA-13–IRDye 800CW administration resulted in decreased bacterial outgrowth from abdominal fluid collected from animals subjected to intraperitoneal PAO1 infection. These observations indicate that CSA-13 may synergistically interact with antibacterial factors that are naturally present at mucosal surfaces and it maintains its antibacterial activity in the infected abdominal cavity. Cationic lipids such as CSA-13 represent excellent candidates for the development of new antibacterial compounds.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2015
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 54, No. 6 ( 2010-06), p. 2525-2533
    Abstract: The rising number of antibiotic-resistant bacterial strains represents an emerging health problem that has motivated efforts to develop new antibacterial agents. Endogenous cationic antibacterial peptides (CAPs) that are produced in tissues exposed to the external environment are one model for the design of novel antibacterial compounds. Here, we report evidence that disubstituted dexamethasone-spermine (D2S), a cationic corticosteroid derivative initially identified as a by-product of synthesis of dexamethasone-spermine (DS) for the purpose of improving cellular gene delivery, functions as an antibacterial peptide-mimicking molecule. This moiety exhibits bacterial killing activity against clinical isolates of Staphylococcus aureus , Pseudomonas aeruginosa present in cystic fibrosis (CF) sputa, and Pseudomonas aeruginosa biofilm. Although compromised in the presence of plasma, D2S antibacterial activity resists the proteolytic activity of pepsin and is maintained in ascites, cerebrospinal fluid, saliva, and bronchoalveolar lavage (BAL) fluid. D2S also enhances S. aureus susceptibility to antibiotics, such as amoxicillin (AMC), tetracycline (T), and amikacin (AN). Inhibition of interleukin-6 (IL-6) and IL-8 release from lipopolysaccharide (LPS)- or lipoteichoic acid (LTA)-treated neutrophils in the presence of D2S suggests that this molecule might also prevent systemic inflammation caused by bacterial wall products. D2S-mediated translocation of green fluorescent protein (GFP)-labeled glucocorticoid receptor (GR) in bovine aorta endothelial cells (BAECs) suggests that some of its anti-inflammatory activities involve engagement of glucocorticoid receptors. The combined antibacterial and anti-inflammatory activities of D2S suggest its potential as an alternative to natural CAPs in the prevention and treatment of some bacterial infections.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2010
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: APMIS, Wiley, Vol. 118, No. 11 ( 2010-11), p. 830-836
    Type of Medium: Online Resource
    ISSN: 0903-4641
    URL: Issue
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2010
    detail.hit.zdb_id: 2098213-6
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Online Resource
    Online Resource
    Elsevier BV ; 1994
    In:  Gastroenterology Vol. 106, No. 3 ( 1994-03), p. 813-814
    In: Gastroenterology, Elsevier BV, Vol. 106, No. 3 ( 1994-03), p. 813-814
    Type of Medium: Online Resource
    ISSN: 0016-5085
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 1994
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 48, No. 5 ( 2004-05), p. 1526-1533
    Abstract: The growing number of antibiotic-resistant bacteria necessitates the search for new antimicrobial agents and the principles by which they work. We report that cell membrane-permeant rhodamine B (RhB)-conjugated peptides based on the phosphatidylinositol-4,5-bisphosphate binding site of gelsolin can kill the gram-negative organisms Escherichia coli and Pseudomonas aeruginosa and the gram-positive organism Streptococcus pneumoniae . RhB linkage to the QRLFQVKGRR sequence in gelsolin was essential for the antibacterial function, since the unconjugated peptide had no effect on the bacteria tested. Because RhB-QRLFQVKGRR (also termed PBP10), its scrambled sequence (RhB-FRVKLKQGQR), and PBP10 synthesized from d -isomer amino acids show similar antibacterial properties, the physical and chemical properties of these derivatives appear to be more important than specific peptide folding for their antibacterial functions. The similar activities of PBP10 and all- d -amino-acid PBP10 also indicate that a specific interaction between RhB derivatives and bacterial proteins is unlikely to be involved in the bacterial killing function of PBP10. By using a phospholipid monolayer system, we found a positive correlation between the antibacterial function of PBP10, as well as some naturally occurring antibacterial peptides, and the intrinsic surface pressure activity at the hydrophobic-hydrophilic interface. Surprisingly, we observed little or no dependence of the insertion of these peptides into lipid monolayers on the phospholipid composition. These studies show that an effective antimicrobial agent can be produced from a peptide sequence with specificity to a phospholipid not found in bacteria, and comparisons with other antimicrobial agents suggest that the surface activities of these peptides are more important than specific binding to bacterial proteins or lipids for their antimicrobial functions.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2004
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Online Resource
    Online Resource
    The American Association of Immunologists ; 2007
    In:  The Journal of Immunology Vol. 178, No. 1_Supplement ( 2007-04-01), p. S133-S134
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 178, No. 1_Supplement ( 2007-04-01), p. S133-S134
    Abstract: At the contact interface between T-cell and antigen presenting cell (APC), peptide antigen presented by MHC (pMHC) binds to T-cell receptor (TCR) and initiates signaling. The mechanism of TCR signal initiation, or triggering, remains unclear. A critical yet controversial issue is whether monomeric agonist pMHC is sufficient to trigger TCR, or if simultaneous engagement of TCRs by two pMHCs is required. Here, we show that CD4+ T-cells are triggered by very low numbers of monomeric agonist pMHCs anchored on fluid planar lipid bilayers. T-cells responded to bilayer-anchored agonist MCC-IEk in a sub-linear fashion, further indicating the sufficiency of monovalent ligand. Moreover, on bilayers, fixed plastic surfaces, or live APCs, endogenous pMHC did not enhance TCR triggering by agonist pMHC. Therefore, agonist pMHCs trigger TCR as individual monomers, independent of endogenous pMHC, supporting a model of TCR triggering by conformational change or kinetic segregation, and not via pMHC pseudodimers.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2007
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Online Resource
    Online Resource
    The American Association of Immunologists ; 2011
    In:  The Journal of Immunology Vol. 186, No. 1_Supplement ( 2011-04-01), p. 109.19-109.19
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 186, No. 1_Supplement ( 2011-04-01), p. 109.19-109.19
    Abstract: T lymphocytes (T cells) recognize antigens through the binding of T cell receptors (TCRs) to peptide ligands presented by MHC molecules (pMHCs) on antigen presenting cells (APCs). The mechanism of how pMHC-TCR binding triggers a signal from TCR is still unclear. One unique aspect of TCR triggering is that surface-anchored pMHC triggers TCR highly efficiently in a two dimensional setting, while soluble monomeric pMHC ligands with full three dimensional freedom have no activity. Here, we investigate the dependence of TCR triggering on the 3D freedom of pMHC ligands using highly flexible hetero-bifunctional poly(ethylene glycol) (PEG) polymer linkers. Fluorescence resonance energy transfer assay showed increased 3D freedom of ligands with increased linker length. As measured by IL2 production, T cells responded equally well to pMHCs anchored on surfaces with 0.56 nm, 3.1 nm and 12.7 nm linkers. T cell response started to decrease, however, when the linker was 22 nm long, and decreased further for the 32 nm linker. pMHCs anchored with the 48 nm linker still stimulated T cells IL2 production, although with only about one tenth the potency. Therefore, pMHC ligands with 3D freedom of up to 22 nm are well tolerated by TCR, but larger 3D freedom gradually reduces potency. Our findings argue against the kinetic segregation of TCR triggering but are in support of receptor deformation, a model of TCR triggering that tolerates increased ligand 3D freedom.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2011
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    In: Circulation Research, Ovid Technologies (Wolters Kluwer Health), Vol. 107, No. 10 ( 2010-11-12), p. 1241-1252
    Abstract: The extracellular matrix (ECM) is a major determinant of the structural integrity and functional properties of the myocardium in common pathological conditions, and changes in vasculature contribute to cardiac dysfunction. Collagen (Col) XV is preferentially expressed in the ECM of cardiac muscle and microvessels. Objective: We aimed to characterize the ECM, cardiovascular function and responses to elevated cardiovascular load in mice lacking Col XV ( Col15a1 −/− ) to define its functional role in the vasculature and in age- and hypertension-associated myocardial remodeling. Methods and Results: Cardiac structure and vasculature were analyzed by light and electron microscopy. Cardiac function, intraarterial blood pressure, microhemodynamics, and gene expression profiles were studied using echocardiography, telemetry, intravital microscopy, and PCR, respectively. Experimental hypertension was induced with angiotensin II or with a nitric oxide synthesis inhibitor. Under basal conditions, lack of Col XV resulted in increased permeability and impaired microvascular hemodynamics, distinct early-onset and age-dependent defects in heart structure and function, a poorly organized fibrillar collagen matrix with marked interstitial deposition of nonfibrillar protein aggregates, increased tissue stiffness, and irregularly organized cardiomyocytes. In response to experimental hypertension, Col15a1 gene expression was increased in the left ventricle of wild-type mice, and mRNA expression of natriuretic peptides (ANP and BNP) and ECM modeling were abnormal in Col15a1 −/− mice. Conclusions: Col XV is necessary for ECM organization in the heart, and for the structure and functions of microvessels. Col XV deficiency leads to a complex cardiac phenotype and predisposes the subject to pathological responses under cardiac stress.
    Type of Medium: Online Resource
    ISSN: 0009-7330 , 1524-4571
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2010
    detail.hit.zdb_id: 1467838-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...