共查询到20条相似文献,搜索用时 15 毫秒
1.
Bruce Pulford Natalia Reim Aimee Bell Jessica Veatch Genevieve Forster Heather Bender Crystal Meyerett Scott Hafeman Brady Michel Theodore Johnson A. Christy Wyckoff Gino Miele Christian Julius Jan Kranich Alan Schenkel Steven Dow Mark D. Zabel 《PloS one》2010,5(6)
Background
Recent advances toward an effective therapy for prion diseases employ RNA interference to suppress PrPC expression and subsequent prion neuropathology, exploiting the phenomenon that disease severity and progression correlate with host PrPC expression levels. However, delivery of lentivirus encoding PrP shRNA has demonstrated only modest efficacy in vivo.Methodology/Principal Findings
Here we describe a new siRNA delivery system incorporating a small peptide that binds siRNA and acetylcholine receptors (AchRs), acting as a molecular messenger for delivery to neurons, and cationic liposomes that protect siRNA-peptide complexes from serum degradation.Conclusions/Significance
Liposome-siRNA-peptide complexes (LSPCs) delivered PrP siRNA specifically to AchR-expressing cells, suppressed PrPC expression and eliminated PrPRES formation in vitro. LSPCs injected intravenously into mice resisted serum degradation and delivered PrP siRNA throughout the brain to AchR and PrPC-expressing neurons. These data promote LSPCs as effective vehicles for delivery of PrP and other siRNAs specifically to neurons to treat prion and other neuropathological diseases. 相似文献2.
Morel E Fouquet S Strup-Perrot C Pichol Thievend C Thievend CP Petit C Loew D Faussat AM Yvernault L Pinçon-Raymond M Chambaz J Rousset M Thenet S Clair C 《PloS one》2008,3(8):e3000
Background
The physiological function of the ubiquitous cellular prion protein, PrPc, is still under debate. It was essentially studied in nervous system, but poorly investigated in epithelial cells. We previously reported that PrPc is targeted to cell–cell junctions of polarized epithelial cells, where it interacts with c-Src.Methodology/Findings
We show here that, in cultured human enterocytes and in intestine in vivo, the mature PrPc is differentially targeted either to the nucleus in dividing cells or to cell–cell contacts in polarized/differentiated cells. By proteomic analysis, we demonstrate that the junctional PrPc interacts with cytoskeleton-associated proteins, such as gamma- and beta-actin, alpha-spectrin, annexin A2, and with the desmosome-associated proteins desmoglein, plakoglobin and desmoplakin. In addition, co-immunoprecipitation experiments revealed complexes associating PrPc, desmoglein and c-Src in raft domains. Through siRNA strategy, we show that PrPc is necessary to complete the process of epithelial cell proliferation and for the sub-cellular distribution of proteins involved in cell architecture and junctions. Moreover, analysis of the architecture of the intestinal epithelium of PrPc knock-out mice revealed a net decrease in the size of desmosomal junctions and, without change in the amount of BrdU incorporation, a shortening of the length of intestinal villi.Conclusions/Significance
From these results, PrPc could be considered as a new partner involved in the balance between proliferation and polarization/differentiation in epithelial cells. 相似文献3.
Emiliano Biasini Laura Tapella Susanna Mantovani Matteo Stravalaci Marco Gobbi David A. Harris Roberto Chiesa 《PloS one》2009,4(11)
Background
Prion diseases are fatal neurodegenerative disorders that can arise sporadically, be genetically inherited or acquired through infection. The key event in these diseases is misfolding of the cellular prion protein (PrPC) into a pathogenic isoform that is rich in β-sheet structure. This conformational change may result in the formation of PrPSc, the prion isoform of PrP, which propagates itself by imprinting its aberrant conformation onto PrPC molecules. A great deal of effort has been devoted to developing protocols for purifying PrPSc for structural studies, and testing its biological properties. Most procedures rely on protease digestion, allowing efficient purification of PrP27-30, the protease-resistant core of PrPSc. However, protease treatment cannot be used to isolate abnormal forms of PrP lacking conventional protease resistance, such as those found in several genetic and atypical sporadic cases.Principal Findings
We developed a method for purifying pathological PrP molecules based on sequential centrifugation and immunoprecipitation with a monoclonal antibody selective for aggregated PrP. With this procedure we purified full-length PrPSc and mutant PrP aggregates at electrophoretic homogeneity. PrPSc purified from prion-infected mice was able to seed misfolding of PrPC in a protein misfolding cyclic amplification reaction, and mutant PrP aggregates from transgenic mice were toxic to cultured neurons.Significance
The immunopurification protocol described here isolates biologically active forms of aggregated PrP. These preparations may be useful for investigating the structural and chemico-physical properties of infectious and neurotoxic PrP aggregates. 相似文献4.
Background
A hallmark of the prion diseases is the conversion of the host-encoded cellular prion protein (PrPC) into a disease related, alternatively folded isoform (PrPSc). The accumulation of PrPSc within the brain is associated with synapse loss and ultimately neuronal death. Novel therapeutics are desperately required to treat neurodegenerative diseases including the prion diseases.Principal Findings
Treatment with glimepiride, a sulphonylurea approved for the treatment of diabetes mellitus, induced the release of PrPC from the surface of prion-infected neuronal cells. The cell surface is a site where PrPC molecules may be converted to PrPSc and glimepiride treatment reduced PrPSc formation in three prion infected neuronal cell lines (ScN2a, SMB and ScGT1 cells). Glimepiride also protected cortical and hippocampal neurones against the toxic effects of the prion-derived peptide PrP82–146. Glimepiride treatment significantly reduce both the amount of PrP82–146 that bound to neurones and PrP82–146 induced activation of cytoplasmic phospholipase A2 (cPLA2) and the production of prostaglandin E2 that is associated with neuronal injury in prion diseases. Our results are consistent with reports that glimepiride activates an endogenous glycosylphosphatidylinositol (GPI)-phospholipase C which reduced PrPC expression at the surface of neuronal cells. The effects of glimepiride were reproduced by treatment of cells with phosphatidylinositol-phospholipase C (PI-PLC) and were reversed by co-incubation with p-chloromercuriphenylsulphonate, an inhibitor of endogenous GPI-PLC.Conclusions
Collectively, these results indicate that glimepiride may be a novel treatment to reduce PrPSc formation and neuronal damage in prion diseases. 相似文献5.
Victoria A. Lawson Brooke Lumicisi Jeremy Welton Dorothy Machalek Katrina Gouramanis Helen M. Klemm James D. Stewart Colin L. Masters David E. Hoke Steven J. Collins Andrew F. Hill 《PloS one》2010,5(8)
Background
The accumulation of protease resistant conformers of the prion protein (PrPres) is a key pathological feature of prion diseases. Polyanions, including RNA and glycosaminoglycans have been identified as factors that contribute to the propagation, transmission and pathogenesis of prion disease. Recent studies have suggested that the contribution of these cofactors to prion propagation may be species specific.Methodology/Principal Finding
In this study a cell-free assay was used to investigate the molecular basis of polyanion stimulated PrPres formation using brain tissue or cell line derived murine PrP. Enzymatic depletion of endogenous nucleic acids or heparan sulphate (HS) from the PrPC substrate was found to specifically prevent PrPres formation seeded by mouse derived PrPSc. Modification of the negative charge afforded by the sulphation of glycosaminoglycans increased the ability of a familial PrP mutant to act as a substrate for PrPres formation, while having no effect on PrPres formed by wildtype PrP. This difference may be due to the observed differences in the binding of wild type and mutant PrP for glycosaminoglycans.Conclusions/Significance
Cofactor requirements for PrPres formation are host species and prion strain specific and affected by disease associated mutations of the prion protein. This may explain both species and strain dependent propagation characteristics and provide insights into the underlying mechanisms of familial prion disease. It further highlights the challenge of designing effective therapeutics against a disease which effects a range of mammalian species, caused by range of aetiologies and prion strains. 相似文献6.
Konstantinos Xanthopoulos Magdalini Polymenidou Sue J. Bellworthy Sylvie L. Benestad Theodoros Sklaviadis 《PloS one》2009,4(5)
Background
A key event in transmissible spongiform encephalopathies (TSEs) is the conversion of the soluble, protease-sensitive glycosylated prion protein (PrPC) to an abnormally structured, aggregated and partially protease-resistant isoform (PrPSc). Both PrP isoforms bear two potential glycosylation sites and thus in a typical western blot with an anti-PrP antibody three distinct bands appear, corresponding to the di-, mono- or unglycosylated forms of the protein. The relative intensity and electrophoretic mobility of the three bands are characteristic of each TSE strain and have been used to discriminate between them.Methodology/Principal Findings
In the present study we used lectin-based western blotting to evaluate possible variations in composition within sugar chains carried by PrPSc purified from subjects affected with different TSEs. Our findings indicate that in addition to the already well-documented differences in electrophoretic mobility and amounts of the glycosylated PrPSc forms, TSE strains also vary in the abundance of specific N-linked sugars of the PrPSc protein.Conclusions/Significance
These results imply that PrP glycosylation might fine-tune the conversion of PrPC to PrPSc and could play an accessory role in the appearance of some of the characteristic features of TSE strains. The differences in sugar composition could also be used as an additional tool for discrimination between the various TSEs. 相似文献7.
Background
Genetic prion diseases are linked to point and inserted mutations in the prion protein (PrP) gene that are presumed to favor conversion of the cellular isoform of PrP (PrPC) to the pathogenic one (PrPSc). The pathogenic mechanisms and the subcellular sites of the conversion are not completely understood. Here we introduce several PRNP gene mutations (such as, PrP-KDEL, PrP-3AV, PrP-A117V, PrP-G114V, PrP-P102L and PrP-E200K) into the cultured cells in order to explore the pathogenic mechanism of familial prion disease.Methodology/Principal Findings
To address the roles of aberrant retention of PrP in endoplasmic reticulum (ER), the recombinant plasmids expressing full-length human PrP tailed with an ER signal peptide at the COOH-terminal (PrP-KDEL) and PrP with three amino acids exchange in transmembrane region (PrP-3AV) were constructed. In the preparations of transient transfections, 18-kD COOH-terminal proteolytic resistant fragments (Ctm-PrP) were detected in the cells expressing PrP-KDEL and PrP-3AV. Analyses of the cell viabilities in the presences of tunicamycin and brefeldin A revealed that expressions of PrP-KDEL and PrP-3AV sensitized the transfected cells to ER stress stimuli. Western blots and RT-PCR identified the clear alternations of ER stress associated events in the cells expressing PrP-KDEL and PrP-3AV that induced ER mediated apoptosis by CHOP and capase-12 apoptosis pathway. Moreover, several familial CJD related PrP mutants were transiently introduced into the cultured cells. Only the mutants within the transmembrane region (G114V and A117V) induced the formation of Ctm-PrP and caused the ER stress, while the mutants outside the transmembrane region (P102L and E200K) failed.Conclusions/Significance
The data indicate that the retention of PrP in ER through formation of Ctm-PrP results in ER stress and cell apoptosis. The cytopathic activities caused by different familial CJD associated PrP mutants may vary, among them the mutants within the transmembrane region undergo an ER-stress mediated cell apoptosis. 相似文献8.
Alejandra Rangel Noelia Madro?al Agnès Gruart i. Massó Rosalina Gavín Franc Llorens Lauro Sumoy Juan María Torres José María Delgado-García José Antonio Del Río 《PloS one》2009,4(10)
Background
Prionopathies are characterized by spongiform brain degeneration, myoclonia, dementia, and periodic electroencephalographic (EEG) disturbances. The hallmark of prioniopathies is the presence of an abnormal conformational isoform (PrPsc) of the natural cellular prion protein (PrPc) encoded by the Prnp gene. Although several roles have been attributed to PrPc, its putative functions in neuronal excitability are unknown. Although early studies of the behavior of Prnp knockout mice described minor changes, later studies report altered behavior. To date, most functional PrPc studies on synaptic plasticity have been performed in vitro. To our knowledge, only one electrophysiological study has been performed in vivo in anesthetized mice, by Curtis and coworkers. They reported no significant differences in paired-pulse facilitation or LTP in the CA1 region after Schaffer collateral/commissural pathway stimulation.Methodology/Principal Findings
Here we explore the role of PrPc expression in neurotransmission and neural excitability using wild-type, Prnp −/− and PrPc-overexpressing mice (Tg20 strain). By correlating histopathology with electrophysiology in living behaving mice, we demonstrate that both Prnp −/− mice but, more relevantly Tg20 mice show increased susceptibility to KA, leading to significant cell death in the hippocampus. This finding correlates with enhanced synaptic facilitation in paired-pulse experiments and hippocampal LTP in living behaving mutant mice. Gene expression profiling using Illumina™ microarrays and Ingenuity pathways analysis showed that 129 genes involved in canonical pathways such as Ubiquitination or Neurotransmission were co-regulated in Prnp −/− and Tg20 mice. Lastly, RT-qPCR of neurotransmission-related genes indicated that subunits of GABAA and AMPA-kainate receptors are co-regulated in both Prnp −/− and Tg20 mice.Conclusions/Significance
Present results demonstrate that PrPc is necessary for the proper homeostatic functioning of hippocampal circuits, because of its relationships with GABAA and AMPA-Kainate neurotransmission. New PrPc functions have recently been described, which point to PrPc as a target for putative therapies in Alzheimer''s disease. However, our results indicate that a “gain of function” strategy in Alzheimer''s disease, or a “loss of function” in prionopathies, may impair PrPc function, with devastating effects. In conclusion, we believe that present data should be taken into account in the development of future therapies. 相似文献9.
Randi S?rby Lars Austb? Charles McL. Press Grethe Skretting Thor Landsverk Arild Espenes 《PloS one》2009,4(9)
Background
In prion disease, the peripheral expression of PrPC is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrPSc accumulation, localisation of nerve fibres and PrPC expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep.Methodology/Principal Findings
Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrPC and PrPSc in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrPSc in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrPSc and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrPSc and nerves. Some nerve fibres were observed to accompany blood vessels into the PrPSc-laden germinal centres. However, the close association between nerves and PrPSc was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres.Conclusions/Significance
The findings suggest that the degree of PrPSc accumulation does not depend on the expression level of PrPC. Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrPSc. 相似文献10.
Dola Das Xiu Luo Ajay Singh Yaping Gu Soumya Ghosh Chinmay K. Mukhopadhyay Shu G. Chen Man-Sun Sy Qingzhong Kong Neena Singh 《PloS one》2010,5(7)
Background
Imbalance of iron homeostasis has been reported in sporadic Creutzfeldt-Jakob-disease (sCJD) affected human and scrapie infected animal brains, but the contribution of this phenotype to disease associated neurotoxicity is unclear.Methodology/Principal Findings
Using cell models of familial prion disorders, we demonstrate that exposure of cells expressing normal prion protein (PrPC) or mutant PrP forms to a source of redox-iron induces aggregation of PrPC and specific mutant PrP forms. Initially this response is cytoprotective, but becomes increasingly toxic with time due to accumulation of PrP-ferritin aggregates. Mutant PrP forms that do not aggregate are not cytoprotective, and cells show signs of acute toxicity. Intracellular PrP-ferritin aggregates induce the expression of LC3-II, indicating stimulation of autophagy in these cells. Similar observations are noted in sCJD and scrapie infected hamster brains, lending credence to these results. Furthermore, phagocytosis of PrP-ferritin aggregates by astrocytes is cytoprotective, while culture in astrocyte conditioned medium (CM) shows no measurable effect. Exposure to H2O2, on the other hand, does not cause aggregation of PrP, and cells show acute toxicity that is alleviated by CM.Conclusions/Significance
These observations suggest that aggregation of PrP in response to redox-iron is cytoprotective. However, subsequent co-aggregation of PrP with ferritin induces intracellular toxicity unless the aggregates are degraded by autophagosomes or phagocytosed by adjacent scavenger cells. H2O2, on the other hand, does not cause aggregation of PrP, and induces toxicity through extra-cellular free radicals. Together with previous observations demonstrating imbalance of iron homeostasis in prion disease affected brains, these observations provide insight into the mechanism of neurotoxicity by redox-iron, and the role of PrP in this process. 相似文献11.
Myriam Ermonval Anne Baudry Florence Baychelier Elodie Pradines Mathéa Pietri Kimimitsu Oda Beno?t Schneider Sophie Mouillet-Richard Jean-Marie Launay Odile Kellermann 《PloS one》2009,4(8)
Background
The cellular prion protein, PrPC, is GPI anchored and abundant in lipid rafts. The absolute requirement of PrPC in neurodegeneration associated to prion diseases is well established. However, the function of this ubiquitous protein is still puzzling. Our previous work using the 1C11 neuronal model, provided evidence that PrPC acts as a cell surface receptor. Besides a ubiquitous signaling function of PrPC, we have described a neuronal specificity pointing to a role of PrPC in neuronal homeostasis. 1C11 cells, upon appropriate induction, engage into neuronal differentiation programs, giving rise either to serotonergic (1C115-HT) or noradrenergic (1C11NE) derivatives.Methodology/Principal Findings
The neuronal specificity of PrPC signaling prompted us to search for PrPC partners in 1C11-derived bioaminergic neuronal cells. We show here by immunoprecipitation an association of PrPC with an 80 kDa protein identified by mass spectrometry as the tissue non-specific alkaline phosphatase (TNAP). This interaction occurs in lipid rafts and is restricted to 1C11-derived neuronal progenies. Our data indicate that TNAP is implemented during the differentiation programs of 1C115-HT and 1C11NE cells and is active at their cell surface. Noteworthy, TNAP may contribute to the regulation of serotonin or catecholamine synthesis in 1C115-HT and 1C11NE bioaminergic cells by controlling pyridoxal phosphate levels. Finally, TNAP activity is shown to modulate the phosphorylation status of laminin and thereby its interaction with PrP.Conclusion/Significance
The identification of a novel PrPC partner in lipid rafts of neuronal cells favors the idea of a role of PrP in multiple functions. Because PrPC and laminin functionally interact to support neuronal differentiation and memory consolidation, our findings introduce TNAP as a functional protagonist in the PrPC-laminin interplay. The partnership between TNAP and PrPC in neuronal cells may provide new clues as to the neurospecificity of PrPC function. 相似文献12.
Background
Prion diseases are fatal neurodegenerative disorders characterized by misfolding and aggregation of the normal prion protein PrPC. Little is known about the details of the structural rearrangement of physiological PrPC into a still-elusive disease-associated conformation termed PrPSc. Increasing evidence suggests that the amino-terminal octapeptide sequences of PrP (huPrP, residues 59–89), though not essential, play a role in modulating prion replication and disease presentation.Methodology/Principal Findings
Here, we report that trypsin digestion of PrPSc from variant and sporadic human CJD results in a disease-specific trypsin-resistant PrPSc fragment including amino acids ∼49–231, thus preserving important epitopes such as the octapeptide domain for biochemical examination. Our immunodetection analyses reveal that several epitopes buried in this region of PrPSc are exposed in PrPC.Conclusions/Significance
We conclude that the octapeptide region undergoes a previously unrecognized conformational transition in the formation of PrPSc. This phenomenon may be relevant to the mechanism by which the amino terminus of PrPC participates in PrPSc conversion, and may also be exploited for diagnostic purposes. 相似文献13.
Molecular structure of amyloid fibrils controls the relationship between fibrillar size and toxicity
Background
According to the prevailing view, soluble oligomers or small fibrillar fragments are considered to be the most toxic species in prion diseases. To test this hypothesis, two conformationally different amyloid states were produced from the same highly pure recombinant full-length prion protein (rPrP). The cytotoxic potential of intact fibrils and fibrillar fragments generated by sonication from these two states was tested using cultured cells.Methodology/Principal Findings
For one amyloid state, fibril fragmentation was found to enhance its cytotoxic potential, whereas for another amyloid state formed within the same amino acid sequence, the fragmented fibrils were found to be substantially less toxic than the intact fibrils. Consistent with the previous studies, the toxic effects were more pronounced for cell cultures expressing normal isoform of the prion protein (PrPC) at high levels confirming that cytotoxicity was in part PrPC-dependent. Silencing of PrPC expression by small hairpin RNAs designed to silence expression of human PrPC (shRNA-PrPC) deminished the deleterious effects of the two amyloid states to a different extent, suggesting that the role of PrPC-mediated and PrPC-independent mechanisms depends on the structure of the aggregates.Conclusions/Significance
This work provides a direct illustration that the relationship between an amyloid''s physical dimension and its toxic potential is not unidirectional but is controlled by the molecular structure of prion protein (PrP) molecules within aggregated states. Depending on the structure, a decrease in size of amyloid fibrils can either enhance or abolish their cytotoxic effect. Regardless of the molecular structure or size of PrP aggregates, silencing of PrPC expression can be exploited to reduce their deleterious effects. 相似文献14.
15.
Etienne Levavasseur Isabelle Laffont-Proust émilie Morain Baptiste A. Faucheux Nicolas Privat Katell Peoc'h Véronique Sazdovitch Jean-Philippe Brandel Jean-Jacques Hauw Stéphane Ha?k 《PloS one》2008,3(7)
Objective
The glycoprofile of pathological prion protein (PrPres) is widely used as a diagnosis marker in Creutzfeldt-Jakob disease (CJD) and is thought to vary in a strain-specific manner. However, that the same glycoprofile of PrPres always accumulates in the whole brain of one individual has been questioned. We aimed to determine whether and how PrPres glycosylation is regulated in the brain of patients with sporadic and variant Creutzfeldt-Jakob disease.Methods
PrPres glycoprofiles in four brain regions from 134 patients with sporadic or variant CJD were analyzed as a function of the genotype at codon 129 of PRNP and the Western blot type of PrPres.Results
The regional distribution of PrPres glycoforms within one individual was heterogeneous in sporadic but not in variant CJD. PrPres glycoforms ratio significantly correlated with the genotype at codon 129 of the prion protein gene and the Western blot type of PrPres in a region-specific manner. In some cases of sCJD, the glycoprofile of thalamic PrPres was undistinguishable from that observed in variant CJD.Interpretation
Regulations leading to variations of PrPres pattern between brain regions in sCJD patients, involving host genotype and Western blot type of PrPres may contribute to the specific brain targeting of prion strains and have direct implications for the diagnosis of the different forms of CJD. 相似文献16.
Oboznaya MB Gilch S Titova MA Koroev DO Volkova TD Volpina OM Schätzl HM 《Cellular and molecular neurobiology》2007,27(3):271-284
Summary 1. Vaccination-induced anti-prion protein antibodies are presently regarded as a promising approach toward treatment of prion
diseases. Here, we investigated the ability of five peptides corresponding to three different regions of the bovine prion
protein (PrP) to elicit antibodies interfering with PrPSc propagation in prion-infected cells.
2. Rabbits were immunized with free nonconjugated peptides. Obtained immune sera were tested in enzyme-linked immunosorbent
assay (ELISA) and immunoblot for their binding to recombinant PrP and cell-derived pathogenic isoform (PrPSc) and normal prion protein (PrPc), respectively. Sera positive in all tests were chosen for PrPSc inhibition studies in cell culture.
3. All peptides induced anti-peptide antibodies, most of them reacting with recombinant PrP. Moreover, addition of the serum
specific to peptide 95–123 led to a transient reduction of PrPSc levels in persistently prion-infected cells.
4. Thus, anti-PrP antibodies interfering with PrPSc propagation were induced with a prion protein peptide nonconjugated to a protein carrier. These results point to the potential
application of the nonconjugated peptide 95–123 for the treatment of prion diseases. 相似文献
17.
Praveen Papareddy Martina Kalle Ole E. S?rensen Katarina Lundqvist Matthias M?rgelin Martin Malmsten Artur Schmidtchen 《PloS one》2012,7(12)
Background
Tissue factor pathway inhibitor 2 (TFPI-2) is a matrix-associated serine protease inhibitor with an enigmatic function in vivo. Here, we describe that TFPI-2 is present in fibrin of wounds and also expressed in skin, where it is up-regulated upon wounding.Methodology and Principal Findings
Neutrophil elastase cleaved TFPI-2, and a C-terminal fragment was found to bind to bacteria. Similarly, a prototypic peptide representing this C-terminal part, EDC34, bound to bacteria and bacterial lipopolysaccharide, and induced bacterial permeabilization. The peptide also induced leakage in artificial liposomes, and displayed a random coil conformation upon interactions with liposomes as well as lipopolysaccharide. EDC34 was antibacterial against both Gram-negative and Gram-positive bacteria in physiological buffer conditions.Conclusions/Significance
The results demonstrate that the C-terminus of TFPI-2 encodes for antimicrobial activity, and may be released during wounding. 相似文献18.
Background
To induce potent epitope-specific T cell immunity by a peptide-based vaccine, epitope peptides must be delivered efficiently to antigen-presenting cells (APCs) in vivo. Therefore, selecting an appropriate peptide carrier is crucial for the development of an effective peptide vaccine. In this study, we explored new peptide carriers which show enhancement in cytotoxic T lymphocyte (CTL) induction capability.Methodology/Principal Findings
Data from an epitope-specific in vivo CTL assay revealed that phosphatidylserine (PS) has a potent adjuvant effect among candidate materials tested. Further analyses showed that PS-conjugated antigens were preferentially and efficiently captured by professional APCs, in particular, by CD11c+CD11b+MHCII+ conventional dendritic cells (cDCs) compared to multilamellar liposome-conjugates or unconjugated antigens. In addition, PS demonstrated the stimulatory capacity of peptide-specific helper T cells in vivo.Conclusions/Significance
This work indicates that PS is the easily preparable efficient carrier with a simple structure that delivers antigen to professional APCs effectively and induce both helper and cytotoxic T cell responses in vivo. Therefore, PS is a promising novel adjuvant for T cell-inducing peptide vaccines. 相似文献19.
Ravichandran N. Murugan Binu Jacob Mija Ahn Eunha Hwang Hoik Sohn Hyo-Nam Park Eunjung Lee Ji-Hyung Seo Chaejoon Cheong Ky-Youb Nam Jae-Kyung Hyun Ki-Woong Jeong Yangmee Kim Song Yub Shin Jeong Kyu Bang 《PloS one》2013,8(11)
Background
Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability.Methodology/Principal Findings
In an attempt to overcome the issues described above, a set of ultra-short, His-derived antimicrobial peptides (HDAMPs) has been developed for the first time. Through systematic tuning of pendant hydrophobic alkyl tails at the N(π)- and N(τ)-positions on His, and the positive charge of Arg, much higher prokaryotic selectivity was achieved, compared to human AMP LL-37. Additionally, the most potent HDAMPs showed promising dual antimicrobial and anti-inflammatory activities, as well as anti–methicillin-resistant Staphylococcus aureus (MRSA) activity and proteolytic resistance. Our results from transmission electron microscopy, membrane depolarization, confocal laser-scanning microscopy, and calcein-dye leakage experiments propose that HDAMP-1 kills microbial cells via dissipation of the membrane potential by forming pore/ion channels on bacterial cell membranes.Conclusion/Significance
The combination of the ultra-short size, high-prokaryotic selectivity, potent anti-MRSA activity, anti-inflammatory activity, and proteolytic resistance of the designed HDAMP-1, -3, -5, and -6 makes these molecules promising candidates for future antimicrobial therapeutics. 相似文献20.
Dusanka S Skundric Rujuan Dai Vaagn L Zakarian Weili Zhou 《Molecular neurodegeneration》2008,3(1):1-12