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Sample records for lytic infection palmitoylation

  1. Viral infection model with periodic lytic immune response

    International Nuclear Information System (INIS)

    Wang Kaifa; Wang Wendi; Liu Xianning

    2006-01-01

    Dynamical behavior and bifurcation structure of a viral infection model are studied under the assumption that the lytic immune response is periodic in time. The infection-free equilibrium is globally asymptotically stable when the basic reproductive ratio of virus is less than or equal to one. There is a non-constant periodic solution if the basic reproductive ratio of the virus is greater than one. It is found that period doubling bifurcations occur as the amplitude of lytic component is increased. For intermediate birth rates, the period triplication occurs and then period doubling cascades proceed gradually toward chaotic cycles. For large birth rate, the period doubling cascade proceeds gradually toward chaotic cycles without the period triplication, and the inverse period doubling can be observed. These results can be used to explain the oscillation behaviors of virus population, which was observed in chronic HBV or HCV carriers

  2. Differentiation-Dependent KLF4 Expression Promotes Lytic Epstein-Barr Virus Infection in Epithelial Cells.

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    Dhananjay M Nawandar

    2015-10-01

    Full Text Available Epstein-Barr virus (EBV is a human herpesvirus associated with B-cell and epithelial cell malignancies. EBV lytically infects normal differentiated oral epithelial cells, where it causes a tongue lesion known as oral hairy leukoplakia (OHL in immunosuppressed patients. However, the cellular mechanism(s that enable EBV to establish exclusively lytic infection in normal differentiated oral epithelial cells are not currently understood. Here we show that a cellular transcription factor known to promote epithelial cell differentiation, KLF4, induces differentiation-dependent lytic EBV infection by binding to and activating the two EBV immediate-early gene (BZLF1 and BRLF1 promoters. We demonstrate that latently EBV-infected, telomerase-immortalized normal oral keratinocyte (NOKs cells undergo lytic viral reactivation confined to the more differentiated cell layers in organotypic raft culture. Furthermore, we show that endogenous KLF4 expression is required for efficient lytic viral reactivation in response to phorbol ester and sodium butyrate treatment in several different EBV-infected epithelial cell lines, and that the combination of KLF4 and another differentiation-dependent cellular transcription factor, BLIMP1, is highly synergistic for inducing lytic EBV infection. We confirm that both KLF4 and BLIMP1 are expressed in differentiated, but not undifferentiated, epithelial cells in normal tongue tissue, and show that KLF4 and BLIMP1 are both expressed in a patient-derived OHL lesion. In contrast, KLF4 protein is not detectably expressed in B cells, where EBV normally enters latent infection, although KLF4 over-expression is sufficient to induce lytic EBV reactivation in Burkitt lymphoma cells. Thus, KLF4, together with BLIMP1, plays a critical role in mediating lytic EBV reactivation in epithelial cells.

  3. Role of the adenovirus early region 1B tumor antigens in transformation and lytic infection

    NARCIS (Netherlands)

    Bernards, R.A.; Leeuw, M.G.W. de; Houweling, A.; Eb, A.J. van der

    1986-01-01

    We have investigated the contribution of each of the two adenovirus type 5 (Ad5) major early region lb (Elb) proteins in cell transformation and in lytic infection. An Ad5 El plasmid, in which the reading frame for the 19-kDa Elb protein was abolished by a stop codon close to the initiation codon,

  4. The importance of lytic and nonlytic immune responses in viral infections

    DEFF Research Database (Denmark)

    Wodarz, Dominik; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2002-01-01

    Antiviral immune effector mechanisms can be divided broadly into lytic and nonlytic components. We use mathematical models to investigate the fundamental question of which type of response is required to combat different types of viral infection. According to our model, the relative roles...... of the two types of component depend on the cytopathicity of the virus relative to its rate of replication. If the viral cytopathicity is low relative to the rate of viral replication, the model predicts that a combination of lytic and nonlytic effector mechanisms is likely to be required to resolve...

  5. Human natural killer cells prevent infectious mononucleosis features by targeting lytic Epstein-Barr virus infection.

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    Chijioke, Obinna; Müller, Anne; Feederle, Regina; Barros, Mario Henrique M; Krieg, Carsten; Emmel, Vanessa; Marcenaro, Emanuela; Leung, Carol S; Antsiferova, Olga; Landtwing, Vanessa; Bossart, Walter; Moretta, Alessandro; Hassan, Rocio; Boyman, Onur; Niedobitek, Gerald; Delecluse, Henri-Jacques; Capaul, Riccarda; Münz, Christian

    2013-12-26

    Primary infection with the human oncogenic Epstein-Barr virus (EBV) can result in infectious mononucleosis (IM), a self-limiting disease caused by massive lymphocyte expansion that predisposes for the development of distinct EBV-associated lymphomas. Why some individuals experience this symptomatic primary EBV infection, whereas the majority acquires the virus asymptomatically, remains unclear. Using a mouse model with reconstituted human immune system components, we show that depletion of human natural killer (NK) cells enhances IM symptoms and promotes EBV-associated tumorigenesis mainly because of a loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Human Natural Killer Cells Prevent Infectious Mononucleosis Features by Targeting Lytic Epstein-Barr Virus Infection

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    Obinna Chijioke

    2013-12-01

    Full Text Available Primary infection with the human oncogenic Epstein-Barr virus (EBV can result in infectious mononucleosis (IM, a self-limiting disease caused by massive lymphocyte expansion that predisposes for the development of distinct EBV-associated lymphomas. Why some individuals experience this symptomatic primary EBV infection, whereas the majority acquires the virus asymptomatically, remains unclear. Using a mouse model with reconstituted human immune system components, we show that depletion of human natural killer (NK cells enhances IM symptoms and promotes EBV-associated tumorigenesis mainly because of a loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies.

  7. Diversity of phage infection types and associated terminology: the problem with 'Lytic or lysogenic'.

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    Hobbs, Zack; Abedon, Stephen T

    2016-04-01

    Bacteriophages, or phages, are viruses of members of domain Bacteria. These viruses play numerous roles in shaping the diversity of microbial communities, with impact differing depending on what infection strategies specific phages employ. From an applied perspective, these especially are communities containing undesired or pathogenic bacteria that can be modified through phage-mediated bacterial biocontrol, that is, through phage therapy. Here we seek to categorize phages in terms of their infection strategies as well as review or suggest more descriptive, accurate or distinguishing terminology. Categories can be differentiated in terms of (1) whether or not virion release occurs (productive infections versus lysogeny, pseudolysogeny and/or the phage carrier state), (2) the means of virion release (lytic versus chronic release) and (3) the degree to which phages are genetically equipped to display lysogenic cycles (temperate versus non-temperate phages). We address in particular the use or overuse of what can be a somewhat equivocal phrase, 'Lytic or lysogenic', especially when employed as a means of distinguishing among phages types. We suggest that the implied dichotomy is inconsistent with both modern as well as historical understanding of phage biology. We consider, therefore, less ambiguous terminology for distinguishing between 'Lytic' versus 'Lysogenic' phage types. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. A Cell Culture Model of Latent and Lytic Herpes Simplex Virus Type 1 Infection in Spiral Ganglion.

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    Liu, Yuehong; Li, Shufeng

    2015-01-01

    Reactivation of latent herpes simplex virus type 1 (HSV-1) in spiral ganglion neurons (SGNs) is supposed to be one of the causes of idiopathic sudden sensorineural hearing loss. This study aims to establish a cell culture model of latent and lytic HSV-1 infection in spiral ganglia. In the presence of acyclovir, primary cultures of SGNs were latently infected with HSV-1 expressing green fluorescent protein. Four days later, these cells were treated with trichostatin A (TSA), a known chemical reactivator of HSV-1. TCID50 was used to measure the titers of virus in cultures on Vero cells. RNA from cultures was detected for the presence of transcripts of ICP27 and latency-associated transcript (LAT) using reverse transcription polymerase chain reaction. There is no detectable infectious HSV-1 in latently infected cultures, whereas they could be observed in both lytically infected and latently infected/TSA-treated cultures. LAT was the only detectable transcript during latent infection, whereas lytic ICP27 transcript was detected in lytically infected and latently infected/TSA-treated cultures. Cultured SGNs can be both latently and lytically infected with HSV-1. Furthermore, latently infected SGNs can be reactivated using TSA, yielding infectious virus.

  9. Noncanonical microRNAs and endogenous siRNAs in lytic infection of murine gammaherpesvirus.

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    Jing Xia

    Full Text Available MicroRNA (miRNA and endogenous small interfering RNA (endo-siRNA are two essential classes of small noncoding RNAs (sncRNAs in eukaryotes. The class of miRNA is diverse and there exist noncanonical miRNAs that bypass the canonical miRNA biogenesis pathway. In order to identify noncanonical miRNAs and endo-siRNAs responding to virus infection and study their potential function, we sequenced small-RNA species from cells lytically infected with murine gammaherpesvirus 68 (MHV68. In addition to three novel canonical miRNAs in mouse, two antisense miRNAs in virus and 25 novel noncanonical miRNAs, including miRNAs derived from transfer RNAs, small nucleolar RNAs and introns, in the host were identified. These noncanonical miRNAs exhibited features distinct from that of canonical miRNAs in lengths of hairpins, base pairings and first nucleotide preference. Many of the novel miRNAs are conserved in mammals. Besides several known murine endo-siRNAs detected by the sequencing profiling, a novel locus in the mouse genome was identified to produce endo-siRNAs. This novel endo-siRNA locus is comprised of two tandem inverted B4 short interspersed nuclear elements (SINEs. Unexpectedly, the SINE-derived endo-siRNAs were found in a variety of sequencing data and virus-infected cells. Moreover, a murine miRNA was up-regulated more than 35 fold in infected than in mock-treated cells. The putative targets of the viral and the up-regulated murine miRNAs were potentially involved in processes of gene transcription and protein phosphorylation, and localized to membranes, suggesting their potential role in manipulating the host basal immune system during lytic infection. Our results extended the number of noncanonical miRNAs in mammals and shed new light on their potential functions of lytic infection of MHV68.

  10. Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

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    Marie Samanovic

    2009-01-01

    Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

  11. Isolation and life cycle characterization of lytic viruses infecting heterotrophic bacteria and cyanobacteria

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Chan, Amy; Bertelsen, Sif Koldborg

    2010-01-01

    Basic knowledge on viruses infecting heterotrophic bacteria and cyanobacteria is key to future progress in understanding the role of viruses in aquatic systems and the influence of virus–host interactions on microbial mortality, biogeochemical cycles, and genetic exchange. Such studies require......, and discusses the applications and limitations of different isolation procedures. Most work on phage isolation has been carried out with aerobic heterotrophic bacteria and cyanobacteria, culturable both on agar plates and in enriched liquid cultures. The procedures presented here are limited to lytic viruses...... infecting such hosts. In addition to the isolation procedures, methods for life cycle characterization (one-step growth experiments) of bacteriophages and cyanophages are described. Finally, limitations and drawbacks of the proposed methods are assessed and discussed...

  12. Lytic Infection of Lactococcus lactis by Bacteriophages Tuc2009 and c2 Triggers Alternative Transcriptional Host Responses

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    Ainsworth, S.; Zomer, A.L.; Mahony, J.; Sinderen, D. van

    2013-01-01

    Here we present an entire temporal transcriptional profile of Lactococcus lactis subsp. cremoris UC509.9 undergoing lytic infection with two distinct bacteriophages, Tuc2009 and c2. Furthermore, corresponding high-resolution whole-phage genome tiling arrays of both bacteriophages were performed

  13. Toward Understanding Phage:Host Interactions in the Rumen; Complete Genome Sequences of Lytic Phages Infecting Rumen Bacteria

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    Rosalind A. Gilbert

    2017-12-01

    Full Text Available The rumen is known to harbor dense populations of bacteriophages (phages predicted to be capable of infecting a diverse range of rumen bacteria. While bacterial genome sequencing projects are revealing the presence of phages which can integrate their DNA into the genome of their host to form stable, lysogenic associations, little is known of the genetics of phages which utilize lytic replication. These phages infect and replicate within the host, culminating in host lysis, and the release of progeny phage particles. While lytic phages for rumen bacteria have been previously isolated, their genomes have remained largely uncharacterized. Here we report the first complete genome sequences of lytic phage isolates specifically infecting three genera of rumen bacteria: Bacteroides, Ruminococcus, and Streptococcus. All phages were classified within the viral order Caudovirales and include two phage morphotypes, representative of the Siphoviridae and Podoviridae families. The phage genomes displayed modular organization and conserved viral genes were identified which enabled further classification and determination of closest phage relatives. Co-examination of bacterial host genomes led to the identification of several genes responsible for modulating phage:host interactions, including CRISPR/Cas elements and restriction-modification phage defense systems. These findings provide new genetic information and insights into how lytic phages may interact with bacteria of the rumen microbiome.

  14. Viral FGARAT ORF75A promotes early events in lytic infection and gammaherpesvirus pathogenesis in mice

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    Hogan, Chad H.; Oldenburg, Darby G.; Kara, Mehmet

    2018-01-01

    Gammaherpesviruses encode proteins with homology to the cellular purine metabolic enzyme formyl-glycinamide-phosphoribosyl-amidotransferase (FGARAT), but the role of these viral FGARATs (vFGARATs) in the pathogenesis of a natural host has not been investigated. We report a novel role for the ORF75A vFGARAT of murine gammaherpesvirus 68 (MHV68) in infectious virion production and colonization of mice. MHV68 mutants with premature stop codons in orf75A exhibited a log reduction in acute replication in the lungs after intranasal infection, which preceded a defect in colonization of multiple host reservoirs including the mediastinal lymph nodes, peripheral blood mononuclear cells, and the spleen. Intraperitoneal infection rescued splenic latency, but not reactivation. The 75A.stop virus also exhibited defective replication in primary fibroblast and macrophage cells. Viruses produced in the absence of ORF75A were characterized by an increase in the ratio of particles to PFU. In the next round of infection this led to the alteration of early events in lytic replication including the deposition of the ORF75C tegument protein, the accelerated kinetics of viral gene expression, and induction of TNFα release and cell death. Infecting cells to deliver equivalent genomes revealed that ORF75A was required for initiating early events in infection. In contrast with the numerous phenotypes observed in the absence of ORF75A, ORF75B was dispensable for replication and pathogenesis. These studies reveal that murine rhadinovirus vFGARAT family members ORF75A and ORF75C have evolved to perform divergent functions that promote replication and colonization of the host. PMID:29390024

  15. Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates

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    Jin Jing

    2012-07-01

    Full Text Available Abstract Background Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Results Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min and a large burst size (200 PFU/cell. It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9 and at extreme temperatures (between 50°C and 60°C. ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. Conclusion The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent

  16. Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates.

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    Jin, Jing; Li, Zhen-Jiang; Wang, Shu-Wei; Wang, Shan-Mei; Huang, De-Hai; Li, Ya-Hui; Ma, Yun-Yun; Wang, Jin; Liu, Fang; Chen, Xiang-Dong; Li, Guang-Xing; Wang, Xiao-Ting; Wang, Zhong-Quan; Zhao, Guo-Qiang

    2012-07-28

    Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min) and a large burst size (200 PFU/cell). It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9) and at extreme temperatures (between 50°C and 60°C). ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent; thus, it should be further investigated.

  17. Cordycepin enhances Epstein-Barr virus lytic infection and Epstein-Barr virus-positive tumor treatment efficacy by doxorubicin.

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    Du, Yinping; Yu, Jieshi; Du, Li; Tang, Jun; Feng, Wen-Hai

    2016-07-01

    The consistent latent presence of Epstein-Barr virus (EBV) in tumor cells offers potential for virus-targeted therapies. The switch from the latent form of EBV to the lytic form in tumor cells can lead to tumor cell lysis. In this study, we report that a natural small molecule compound, cordycepin, can induce lytic EBV infection in tumor cells. Subsequently, we demonstrate that cordycepin can enhance EBV reactivating capacity and EBV-positive tumor cell killing ability of low dose doxorubicin. The combination of cordycepin and doxorubicin phosphorylates CCAAT/enhancer binding protein β (C/EBPβ) through protein kinase C (PKC)-p38 mitogen activated protein kinases (p38 MAPK) signaling pathway, and C/EBPβ is required for the activation of lytic EBV infection. Most importantly, an in vivo experiment demonstrates that the combination of cordycepin and doxorubicin is more effective in inhibiting tumor growth in SCID mice than is doxorubicin alone. Our findings establish that cordycepin can enhance the efficacy of conventional chemotherapy for treatment of EBV-positive tumors. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Phosphoproteomic Analysis of KSHV-Infected Cells Reveals Roles of ORF45-Activated RSK during Lytic Replication.

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    Denis Avey

    2015-07-01

    Full Text Available Kaposi's Sarcoma-Associated Herpesvirus (KSHV is an oncogenic virus which has adapted unique mechanisms to modulate the cellular microenvironment of its human host. The pathogenesis of KSHV is intimately linked to its manipulation of cellular signaling pathways, including the extracellular signal-regulated kinase (ERK mitogen-activated protein kinase (MAPK pathway. We have previously shown that KSHV ORF45 contributes to the sustained activation of both ERK and p90 ribosomal S6 kinase (RSK, a major functional mediator of ERK/MAPK signaling during KSHV lytic replication. ORF45-activated RSK is required for optimal KSHV lytic gene expression and progeny virion production, though the underlying mechanisms downstream of this activation are still unclear. We hypothesized that the activation of RSK by ORF45 causes differential phosphorylation of cellular and viral substrates, affecting biological processes essential for efficient KSHV lytic replication. Accordingly, we observed widespread and significant differences in protein phosphorylation upon induction of lytic replication. Mass-spectrometry-based phosphoproteomic screening identified putative substrates of ORF45-activated RSK in KSHV-infected cells. Bioinformatic analyses revealed that nuclear proteins, including several transcriptional regulators, were overrepresented among these candidates. We validated the ORF45/RSK-dependent phosphorylation of several putative substrates by employing KSHV BAC mutagenesis, kinase inhibitor treatments, and/or CRISPR-mediated knockout of RSK in KSHV-infected cells. Furthermore, we assessed the consequences of knocking out these substrates on ORF45/RSK-dependent regulation of gene expression and KSHV progeny virion production. Finally, we show data to support that ORF45 regulates the translational efficiency of a subset of viral/cellular genes with complex secondary structure in their 5' UTR. Altogether, these data shed light on the mechanisms by which KSHV ORF45

  19. Global Analysis of Palmitoylated Proteins in Toxoplasma gondii.

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    Foe, Ian T; Child, Matthew A; Majmudar, Jaimeen D; Krishnamurthy, Shruthi; van der Linden, Wouter A; Ward, Gary E; Martin, Brent R; Bogyo, Matthew

    2015-10-14

    Post-translational modifications (PTMs) such as palmitoylation are critical for the lytic cycle of the protozoan parasite Toxoplasma gondii. While palmitoylation is involved in invasion, motility, and cell morphology, the proteins that utilize this PTM remain largely unknown. Using a chemical proteomic approach, we report a comprehensive analysis of palmitoylated proteins in T. gondii, identifying a total of 282 proteins, including cytosolic, membrane-associated, and transmembrane proteins. From this large set of palmitoylated targets, we validate palmitoylation of proteins involved in motility (myosin light chain 1, myosin A), cell morphology (PhIL1), and host cell invasion (apical membrane antigen 1, AMA1). Further studies reveal that blocking AMA1 palmitoylation enhances the release of AMA1 and other invasion-related proteins from apical secretory organelles, suggesting a previously unrecognized role for AMA1. These findings suggest that palmitoylation is ubiquitous throughout the T. gondii proteome and reveal insights into the biology of this important human pathogen. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Recurrent Plasmodium falciparum malaria infections in Kenyan children diminish T-cell immunity to Epstein Barr virus lytic but not latent antigens.

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    Cynthia J Snider

    Full Text Available Plasmodium falciparum malaria (Pf-malaria and Epstein Barr Virus (EBV infections coexist in children at risk for endemic Burkitt's lymphoma (eBL; yet studies have only glimpsed the cumulative effect of Pf-malaria on EBV-specific immunity. Using pooled EBV lytic and latent CD8+ T-cell epitope-peptides, IFN-γ ELISPOT responses were surveyed three times among children (10 months to 15 years in Kenya from 2002-2004. Prevalence ratios (PR and 95% confidence intervals (CI were estimated in association with Pf-malaria exposure, defined at the district-level (Kisumu: holoendemic; Nandi: hypoendemic and the individual-level. We observed a 46% decrease in positive EBV lytic antigen IFN-γ responses among 5-9 year olds residing in Kisumu compared to Nandi (PR: 0.54; 95% CI: 0.30-0.99. Individual-level analysis in Kisumu revealed further impairment of EBV lytic antigen responses among 5-9 year olds consistently infected with Pf-malaria compared to those never infected. There were no observed district- or individual-level differences between Pf-malaria exposure and EBV latent antigen IFN-γ response. The gradual decrease of EBV lytic antigen but not latent antigen IFN-γ responses after primary infection suggests a specific loss in immunological control over the lytic cycle in children residing in malaria holoendemic areas, further refining our understanding of eBL etiology.

  1. De Novo Herpes Simplex Virus VP16 Expression Gates a Dynamic Programmatic Transition and Sets the Latent/Lytic Balance during Acute Infection in Trigeminal Ganglia.

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    Sawtell, Nancy M; Thompson, Richard L

    2016-09-01

    The life long relationship between herpes simplex virus and its host hinges on the ability of the virus to aggressively replicate in epithelial cells at the site of infection and transport into the nervous system through axons innervating the infection site. Interaction between the virus and the sensory neuron represents a pivot point where largely unknown mechanisms lead to a latent or a lytic infection in the neuron. Regulation at this pivot point is critical for balancing two objectives, efficient widespread seeding of the nervous system and host survival. By combining genetic and in vivo in approaches, our studies reveal that the balance between latent and lytic programs is a process occurring early in the trigeminal ganglion. Unexpectedly, activation of the latent program precedes entry into the lytic program by 12 -14hrs. Importantly, at the individual neuronal level, the lytic program begins as a transition out of this acute stage latent program and this escape from the default latent program is regulated by de novo VP16 expression. Our findings support a model in which regulated de novo VP16 expression in the neuron mediates entry into the lytic cycle during the earliest stages of virus infection in vivo. These findings support the hypothesis that the loose association of VP16 with the viral tegument combined with sensory axon length and transport mechanisms serve to limit arrival of virion associated VP16 into neuronal nuclei favoring latency. Further, our findings point to specialized features of the VP16 promoter that control the de novo expression of VP16 in neurons and this regulation is a key component in setting the balance between lytic and latent infections in the nervous system.

  2. Phage lytic enzymes: a history.

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    Trudil, David

    2015-02-01

    There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well (Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specific disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay (Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes-from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.

  3. Herpesviral ICP0 Protein Promotes Two Waves of Heterochromatin Removal on an Early Viral Promoter during Lytic Infection

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    Jennifer S. Lee

    2016-01-01

    Full Text Available Herpesviruses must contend with host cell epigenetic silencing responses acting on their genomes upon entry into the host cell nucleus. In this study, we confirmed that unchromatinized herpes simplex virus 1 (HSV-1 genomes enter primary human foreskin fibroblasts and are rapidly subjected to assembly of nucleosomes and association with repressive heterochromatin modifications such as histone 3 (H3 lysine 9-trimethylation (H3K9me3 and lysine 27-trimethylation (H3K27me3 during the first 1 to 2 h postinfection. Kinetic analysis of the modulation of nucleosomes and heterochromatin modifications over the course of lytic infection demonstrates a progressive removal that coincided with initiation of viral gene expression. We obtained evidence for three phases of heterochromatin removal from an early gene promoter: an initial removal of histones and heterochromatin not dependent on ICP0, a second ICP0-dependent round of removal of H3K9me3 that is independent of viral DNA synthesis, and a third phase of H3K27me3 removal that is dependent on ICP0 and viral DNA synthesis. The presence of ICP0 in transfected cells is also sufficient to promote removal of histones and H3K9me3 modifications of cotransfected genes. Overall, these results show that ICP0 promotes histone removal, a reduction of H3K9me3 modifications, and a later indirect reduction of H3K27me3 modifications following viral early gene expression and DNA synthesis. Therefore, HSV ICP0 promotes the reversal of host epigenetic silencing mechanisms by several mechanisms.

  4. Emergence of CD4+ and CD8+ Polyfunctional T Cell Responses Against Immunodominant Lytic and Latent EBV Antigens in Children With Primary EBV Infection

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    Janice K. P. Lam

    2018-03-01

    Full Text Available Long term carriers were shown to generate robust polyfunctional T cell (PFC responses against lytic and latent antigens of Epstein-Barr virus (EBV. However, the time of emergence of PFC responses against EBV antigens, pattern of immunodominance and difference between CD4+ and CD8+ T cell responses during various stages of EBV infection are not clearly understood. A longitudinal study was performed to assess the development of antigen-specific PFC responses in children diagnosed to have primary symptomatic (infectious mononucleosis [IM] and asymptomatic (AS EBV infection. Evaluation of IFN-γ secreting CD8+ T cell responses upon stimulation by HLA class I-specific peptides of EBV lytic and latent proteins by ELISPOT assay followed by assessment of CD4+ and CD8+ PFC responses upon stimulation by a panel of overlapping EBV peptides for co-expression of IFN-γ, TNF-α, IL-2, perforin and CD107a by flow cytometry were performed. Cytotoxicity of T cells against autologous lymphoblastoid cell lines (LCLs as well as EBV loads in PBMC and plasma were also determined. Both IM and AS patients had elevated PBMC and plasma viral loads which declined steadily during a 12-month period from the time of diagnosis whilst decrease in the magnitude of CD8+ T cell responses toward EBV lytic peptides in contrast to increase toward latent peptides was shown with no significant difference between those of IM and AS patients. Both lytic and latent antigen-specific CD4+ and CD8+ T cells demonstrated polyfunctionality (defined as greater or equal to three functions concurrent with enhanced cytotoxicity against autologous LCLs and steady decrease in plasma and PBMC viral loads over time. Immunodominant peptides derived from BZLF1, BRLF1, BMLF1 and EBNA3A-C proteins induced the highest proportion of CD8+ as well as CD4+ PFC responses. Diverse functional subtypes of both CD4+ and CD8+ PFCs were shown to emerge at 6–12 months. In conclusion, EBV antigen-specific CD4+ and CD

  5. Co-therapy using lytic bacteriophage and linezolid: effective treatment in eliminating methicillin resistant Staphylococcus aureus (MRSA from diabetic foot infections.

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    Sanjay Chhibber

    Full Text Available BACKGROUND: Staphylococcus aureus remains the predominant pathogen in diabetic foot infections and prevalence of methicillin resistant S.aureus (MRSA strains further complicates the situation. The incidence of MRSA in infected foot ulcers is 15-30% and there is an alarming trend for its increase in many countries. Diabetes acts as an immunosuppressive state decreasing the overall immune functioning of body and to worsen the situation, wounds inflicted with drug resistant strains represent a morbid combination in diabetic patients. Foot infections caused by MRSA are associated with an increased risk of amputations, increased hospital stay, increased expenses and higher infection-related mortality. Hence, newer, safer and effective treatment strategies are required for treating MRSA mediated diabetic foot infections. The present study focuses on the use of lytic bacteriophage in combination with linezolid as an effective treatment strategy against foot infection in diabetic population. METHODOLOGY: Acute hindpaw infection with S.aureus ATCC 43300 was established in alloxan induced diabetic BALB/c mice. Therapeutic efficacy of a well characterized broad host range lytic bacteriophage, MR-10 was evaluated alone as well as in combination with linezolid in resolving the course of hindpaw foot infection in diabetic mice. The process of wound healing was also investigated. RESULTS AND CONCLUSIONS: A single administration of phage exhibited efficacy similar to linezolid in resolving the course of hindpaw infection in diabetic animals. However, combination therapy using both the agents was much more effective in arresting the entire infection process (bacterial load, lesion score, foot myeloperoxidase activity and histopathological analysis. The entire process of tissue healing was also hastened. Use of combined agents has been known to decrease the frequency of emergence of resistant mutants, hence this approach can serve as an effective strategy in

  6. Effect of a lytic bacteriophage on rabbits experimentally infected with pathogenic Escherichia coli

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    J. Zhao

    2017-09-01

    Full Text Available Pathogenic Escherichia coli (E. coli is severely threatening the rabbit industry in China, and the concern over antibiotic-resistant bacteria has given rise to an urgent need for antibiotic alternatives. In this study, a member (ZRP1 of the Myoviridae family was isolated from rabbit faeces using a strain of rabbit atypical enteropathogenic E. coli (ZR1 as host. The one-step growth curve indicated that the latent period was around 25 to 30 min and the burst size was 144±31 plaque-forming unit/cell. The rate of phage-resistant mutation was 7×10–5±4×10–5. When the bacteriophage input at the multiplicity of infection (MOI was 0.1, 1 or 10, the growth of host E. coli in broth was inhibited for 5 h. A single intravenous injection of ZRP1 at MOI 0.1, 1 or 10 significantly prolonged the survival time of rabbits which simultaneously received a lethal dose of ZR1.

  7. Lysis to Kill: Evaluation of the Lytic Abilities, and Genomics of Nine Bacteriophages Infective for Gordonia spp. and Their Potential Use in Activated Sludge Foam Biocontrol.

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    Zoe A Dyson

    Full Text Available Nine bacteriophages (phages infective for members of the genus Gordonia were isolated from wastewater and other natural water environments using standard enrichment techniques. The majority were broad host range phages targeting more than one Gordonia species. When their genomes were sequenced, they all emerged as double stranded DNA Siphoviridae phages, ranging from 17,562 to 103,424 bp in size, and containing between 27 and 127 genes, many of which were detailed for the first time. Many of these phage genomes diverged from the expected modular genome architecture of other characterized Siphoviridae phages and contained unusual lysis gene arrangements. Whole genome sequencing also revealed that infection with lytic phages does not appear to prevent spontaneous prophage induction in Gordonia malaquae lysogen strain BEN700. TEM sample preparation techniques were developed to view both attachment and replication stages of phage infection.

  8. SwissPalm: Protein Palmitoylation database.

    Science.gov (United States)

    Blanc, Mathieu; David, Fabrice; Abrami, Laurence; Migliozzi, Daniel; Armand, Florence; Bürgi, Jérôme; van der Goot, Françoise Gisou

    2015-01-01

    Protein S-palmitoylation is a reversible post-translational modification that regulates many key biological processes, although the full extent and functions of protein S-palmitoylation remain largely unexplored. Recent developments of new chemical methods have allowed the establishment of palmitoyl-proteomes of a variety of cell lines and tissues from different species.  As the amount of information generated by these high-throughput studies is increasing, the field requires centralization and comparison of this information. Here we present SwissPalm ( http://swisspalm.epfl.ch), our open, comprehensive, manually curated resource to study protein S-palmitoylation. It currently encompasses more than 5000 S-palmitoylated protein hits from seven species, and contains more than 500 specific sites of S-palmitoylation. SwissPalm also provides curated information and filters that increase the confidence in true positive hits, and integrates predictions of S-palmitoylated cysteine scores, orthologs and isoform multiple alignments. Systems analysis of the palmitoyl-proteome screens indicate that 10% or more of the human proteome is susceptible to S-palmitoylation. Moreover, ontology and pathway analyses of the human palmitoyl-proteome reveal that key biological functions involve this reversible lipid modification. Comparative analysis finally shows a strong crosstalk between S-palmitoylation and other post-translational modifications. Through the compilation of data and continuous updates, SwissPalm will provide a powerful tool to unravel the global importance of protein S-palmitoylation.

  9. Dynamic protein S-palmitoylation mediates parasite life cycle progression and diverse mechanisms of virulence.

    Science.gov (United States)

    Brown, Robert W B; Sharma, Aabha I; Engman, David M

    2017-04-01

    Eukaryotic parasites possess complex life cycles and utilize an assortment of molecular mechanisms to overcome physical barriers, suppress and/or bypass the host immune response, including invading host cells where they can replicate in a protected intracellular niche. Protein S-palmitoylation is a dynamic post-translational modification in which the fatty acid palmitate is covalently linked to cysteine residues on proteins by the enzyme palmitoyl acyltransferase (PAT) and can be removed by lysosomal palmitoyl-protein thioesterase (PPT) or cytosolic acyl-protein thioesterase (APT). In addition to anchoring proteins to intracellular membranes, functions of dynamic palmitoylation include - targeting proteins to specific intracellular compartments via trafficking pathways, regulating the cycling of proteins between membranes, modulating protein function and regulating protein stability. Recent studies in the eukaryotic parasites - Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei, Cryptococcus neoformans and Giardia lamblia - have identified large families of PATs and palmitoylated proteins. Many palmitoylated proteins are important for diverse aspects of pathogenesis, including differentiation into infective life cycle stages, biogenesis and tethering of secretory organelles, assembling the machinery powering motility and targeting virulence factors to the plasma membrane. This review aims to summarize our current knowledge of palmitoylation in eukaryotic parasites, highlighting five exemplary mechanisms of parasite virulence dependent on palmitoylation.

  10. Pediatric and Adult High-Grade Glioma Stem Cell Culture Models Are Permissive to Lytic Infection with Parvovirus H-1.

    Science.gov (United States)

    Josupeit, Rafael; Bender, Sebastian; Kern, Sonja; Leuchs, Barbara; Hielscher, Thomas; Herold-Mende, Christel; Schlehofer, Jörg R; Dinsart, Christiane; Witt, Olaf; Rommelaere, Jean; Lacroix, Jeannine

    2016-05-19

    Combining virus-induced cytotoxic and immunotherapeutic effects, oncolytic virotherapy represents a promising therapeutic approach for high-grade glioma (HGG). A clinical trial has recently provided evidence for the clinical safety of the oncolytic parvovirus H-1 (H-1PV) in adult glioblastoma relapse patients. The present study assesses the efficacy of H-1PV in eliminating HGG initiating cells. H-1PV was able to enter and to transduce all HGG neurosphere culture models (n = 6), including cultures derived from adult glioblastoma, pediatric glioblastoma, and diffuse intrinsic pontine glioma. Cytotoxic effects induced by the virus have been observed in all HGG neurospheres at half maximal inhibitory concentration (IC50) doses of input virus between 1 and 10 plaque forming units per cell. H-1PV infection at this dose range was able to prevent tumorigenicity of NCH421k glioblastoma multiforme (GBM) "stem-like" cells in NOD/SCID mice. Interestingly NCH421R, an isogenic subclone with equal capacity of xenograft formation, but resistant to H-1PV infection could be isolated from the parental NCH421k culture. To reveal changes in gene expression associated with H-1PV resistance we performed a comparative gene expression analysis in these subclones. Several dysregulated genes encoding receptor proteins, endocytosis factors or regulators innate antiviral responses were identified and represent intriguing candidates for to further study molecular mechanisms of H-1PV resistance.

  11. Hypoxia-inducible factor-1α plays roles in Epstein-Barr virus's natural life cycle and tumorigenesis by inducing lytic infection through direct binding to the immediate-early BZLF1 gene promoter.

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    Richard J Kraus

    2017-06-01

    Full Text Available When confronted with poor oxygenation, cells adapt by activating survival signaling pathways, including the oxygen-sensitive transcriptional regulators called hypoxia-inducible factor alphas (HIF-αs. We report here that HIF-1α also regulates the life cycle of Epstein-Barr virus (EBV. Incubation of EBV-positive gastric carcinoma AGS-Akata and SNU-719 and Burkitt lymphoma Sal and KemIII cell lines with a prolyl hydroxylase inhibitor, L-mimosine or deferoxamine, or the NEDDylation inhibitor MLN4924 promoted rapid and sustained accumulation of both HIF-1α and lytic EBV antigens. ShRNA knockdown of HIF-1α significantly reduced deferoxamine-mediated lytic reactivation. HIF-1α directly bound the promoter of the EBV primary latent-lytic switch BZLF1 gene, Zp, activating transcription via a consensus hypoxia-response element (HRE located at nt -83 through -76 relative to the transcription initiation site. HIF-1α did not activate transcription from the other EBV immediate-early gene, BRLF1. Importantly, expression of HIF-1α induced EBV lytic-gene expression in cells harboring wild-type EBV, but not in cells infected with variants containing base-pair substitution mutations within this HRE. Human oral keratinocyte (NOK and gingival epithelial (hGET cells induced to differentiate by incubation with either methyl cellulose or growth in organotypic culture accumulated both HIF-1α and Blimp-1α, another cellular factor implicated in lytic reactivation. HIF-1α activity also accumulated along with Blimp-1α during B-cell differentiation into plasma cells. Furthermore, most BZLF1-expressing cells observed in lymphomas induced by EBV in NSG mice with a humanized immune system were located distal to blood vessels in hypoxic regions of the tumors. Thus, we conclude that HIF-1α plays central roles in both EBV's natural life cycle and EBV-associated tumorigenesis. We propose that drugs that induce HIF-1α protein accumulation are good candidates for

  12. Human Embryonic Stem Cell-Derived Neurons Are Highly Permissive for Varicella-Zoster Virus Lytic Infection.

    Science.gov (United States)

    Sadaoka, Tomohiko; Schwartz, Cindi L; Rajbhandari, Labchan; Venkatesan, Arun; Cohen, Jeffrey I

    2018-01-01

    Varicella-zoster virus (VZV) is highly cell associated when grown in culture and has a much higher (4,000- to 20,000-fold increased) particle-to-PFU ratio in vitro than herpes simplex virus (HSV). In contrast, VZV is highly infectious in vivo by airborne transmission. Neurons are major targets for VZV in vivo ; in neurons, the virus can establish latency and reactivate to produce infectious virus. Using neurons derived from human embryonic stem cells (hESC) and cell-free wild-type (WT) VZV, we demonstrated that neurons are nearly 100 times more permissive for WT VZV infection than very-early-passage human embryonic lung cells or MRC-5 diploid human fibroblasts, the cells used for vaccine production or virus isolation. The peak titers achieved after infection were ∼10-fold higher in human neurons than in MRC-5 cells, and the viral genome copy number-to-PFU ratio for VZV in human neurons was 500, compared with 50,000 for MRC-5 cells. Thus, VZV may not necessarily have a higher particle-to-PFU ratio than other herpesviruses; instead, the cells previously used to propagate virus in vitro may have been suboptimal. Furthermore, based on electron microscopy, neurons infected with VZV produced fewer defective or incomplete viral particles than MRC-5 cells. Our data suggest that neurons derived from hESC may have advantages compared to other cells for studies of VZV pathogenesis, for obtaining stocks of virus with high titers, and for isolating VZV from clinical specimens. IMPORTANCE Varicella-zoster virus (VZV) causes chickenpox and shingles. Cell-free VZV has been difficult to obtain, both for in vitro studies and for vaccine production. While numerous cells lines have been tested for their ability to produce high titers of VZV, the number of total virus particles relative to the number of viral particles that can form plaques in culture has been reported to be extremely high relative to that in other viruses. We show that VZV grows to much higher titers in human

  13. Specificity of transmembrane protein palmitoylation in yeast.

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    Ayelén González Montoro

    Full Text Available Many proteins are modified after their synthesis, by the addition of a lipid molecule to one or more cysteine residues, through a thioester bond. This modification is called S-acylation, and more commonly palmitoylation. This reaction is carried out by a family of enzymes, called palmitoyltransferases (PATs, characterized by the presence of a conserved 50- aminoacids domain called "Asp-His-His-Cys- Cysteine Rich Domain" (DHHC-CRD. There are 7 members of this family in the yeast Saccharomyces cerevisiae, and each of these proteins is thought to be responsible for the palmitoylation of a subset of substrates. Substrate specificity of PATs, however, is not yet fully understood. Several yeast PATs seem to have overlapping specificity, and it has been proposed that the machinery responsible for palmitoylating peripheral membrane proteins in mammalian cells, lacks specificity altogether.Here we investigate the specificity of transmembrane protein palmitoylation in S. cerevisiae, which is carried out predominantly by two PATs, Swf1 and Pfa4. We show that palmitoylation of transmembrane substrates requires dedicated PATs, since other yeast PATs are mostly unable to perform Swf1 or Pfa4 functions, even when overexpressed. Furthermore, we find that Swf1 is highly specific for its substrates, as it is unable to substitute for other PATs. To identify where Swf1 specificity lies, we carried out a bioinformatics survey to identify amino acids responsible for the determination of specificity or Specificity Determination Positions (SDPs and showed experimentally, that mutation of the two best SDP candidates, A145 and K148, results in complete and partial loss of function, respectively. These residues are located within the conserved catalytic DHHC domain suggesting that it could also be involved in the determination of specificity. Finally, we show that modifying the position of the cysteines in Tlg1, a Swf1 substrate, results in lack of palmitoylation, as

  14. Biofilms Formed by Gram-Negative Bacteria Undergo Increased Lipid A Palmitoylation, Enhancing In Vivo Survival

    Science.gov (United States)

    Chalabaev, Sabina; Chauhan, Ashwini; Novikov, Alexey; Iyer, Pavithra; Szczesny, Magdalena; Beloin, Christophe; Caroff, Martine

    2014-01-01

    ABSTRACT Bacterial biofilm communities are associated with profound physiological changes that lead to novel properties compared to the properties of individual (planktonic) bacteria. The study of biofilm-associated phenotypes is an essential step toward control of deleterious effects of pathogenic biofilms. Here we investigated lipopolysaccharide (LPS) structural modifications in Escherichia coli biofilm bacteria, and we showed that all tested commensal and pathogenic E. coli biofilm bacteria display LPS modifications corresponding to an increased level of incorporation of palmitate acyl chain (palmitoylation) into lipid A compared to planktonic bacteria. Genetic analysis showed that lipid A palmitoylation in biofilms is mediated by the PagP enzyme, which is regulated by the histone-like protein repressor H-NS and the SlyA regulator. While lipid A palmitoylation does not influence bacterial adhesion, it weakens inflammatory response and enhances resistance to some antimicrobial peptides. Moreover, we showed that lipid A palmitoylation increases in vivo survival of biofilm bacteria in a clinically relevant model of catheter infection, potentially contributing to biofilm tolerance to host immune defenses. The widespread occurrence of increased lipid A palmitoylation in biofilms formed by all tested bacteria suggests that it constitutes a new biofilm-associated phenotype in Gram-negative bacteria. PMID:25139899

  15. Palmitoylation of Sindbis Virus TF Protein Regulates Its Plasma Membrane Localization and Subsequent Incorporation into Virions.

    Science.gov (United States)

    Ramsey, Jolene; Renzi, Emily C; Arnold, Randy J; Trinidad, Jonathan C; Mukhopadhyay, Suchetana

    2017-02-01

    Palmitoylation is a reversible, posttranslational modification that helps target proteins to cellular membranes. The alphavirus small membrane proteins 6K and TF have been reported to be palmitoylated and to positively regulate budding. 6K and TF are isoforms that are identical in their N termini but unique in their C termini due to a -1 ribosomal frameshift during translation. In this study, we used cysteine (Cys) mutants to test differential palmitoylation of the Sindbis virus 6K and TF proteins. We modularly mutated the five Cys residues in the identical N termini of 6K and TF, the four additional Cys residues in TF's unique C terminus, or all nine Cys residues in TF. Using these mutants, we determined that TF palmitoylation occurs primarily in the N terminus. In contrast, 6K is not palmitoylated, even on these shared residues. In the C-terminal Cys mutant, TF protein levels increase both in the cell and in the released virion compared to the wild type. In viruses with the N-terminal Cys residues mutated, TF is much less efficiently localized to the plasma membrane, and it is not incorporated into the virion. The three Cys mutants have minor defects in cell culture growth but a high incidence of abnormal particle morphologies compared to the wild-type virus as determined by transmission electron microscopy. We propose a model where the C terminus of TF modulates the palmitoylation of TF at the N terminus, and palmitoylated TF is preferentially trafficked to the plasma membrane for virus budding. Alphaviruses are a reemerging viral cause of arthritogenic disease. Recently, the small 6K and TF proteins of alphaviruses were shown to contribute to virulence in vivo Nevertheless, a clear understanding of the molecular mechanisms by which either protein acts to promote virus infection is missing. The TF protein is a component of budded virions, and optimal levels of TF correlate positively with wild-type-like particle morphology. In this study, we show that the

  16. Genomic, proteomic and morphological characterization of two novel broad host lytic bacteriophages ΦPD10.3 and ΦPD23.1 infecting pectinolytic Pectobacterium spp. and Dickeya spp.

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    Robert Czajkowski

    Full Text Available Pectinolytic Pectobacterium spp. and Dickeya spp. are necrotrophic bacterial pathogens of many important crops, including potato, worldwide. This study reports on the isolation and characterization of broad host lytic bacteriophages able to infect the dominant Pectobacterium spp. and Dickeya spp. affecting potato in Europe viz. Pectobacterium carotovorum subsp. carotovorum (Pcc, P. wasabiae (Pwa and Dickeya solani (Dso with the objective to assess their potential as biological disease control agents. Two lytic bacteriophages infecting stains of Pcc, Pwa and Dso were isolated from potato samples collected from two potato fields in central Poland. The ΦPD10.3 and ΦPD23.1 phages have morphology similar to other members of the Myoviridae family and the Caudovirales order, with a head diameter of 85 and 86 nm and length of tails of 117 and 121 nm, respectively. They were characterized for optimal multiplicity of infection, the rate of adsorption to the Pcc, Pwa and Dso cells, the latent period and the burst size. The phages were genotypically characterized with RAPD-PCR and RFLP techniques. The structural proteomes of both phages were obtained by fractionation of phage proteins by SDS-PAGE. Phage protein identification was performed by liquid chromatography-mass spectrometry (LC-MS analysis. Pulsed-field gel electrophoresis (PFGE, genome sequencing and comparative genome analysis were used to gain knowledge of the length, organization and function of the ΦPD10.3 and ΦPD23.1 genomes. The potential use of ΦPD10.3 and ΦPD23.1 phages for the biocontrol of Pectobacterium spp. and Dickeya spp. infections in potato is discussed.

  17. Palmitoylated transmembrane adaptor proteins in leukocyte signaling

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Ondřej; Dráber, Peter; Hořejší, Václav

    2014-01-01

    Roč. 26, č. 5 (2014), s. 895-902 ISSN 0898-6568 R&D Projects: GA ČR(CZ) GBP302/12/G101 Institutional support: RVO:68378050 Keywords : Leukocyte * Adaptor * Palmitoylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.315, year: 2014

  18. Palmitoylation of SARS-CoV S protein is necessary for partitioning into detergent-resistant membranes and cell-cell fusion but not interaction with M protein

    International Nuclear Information System (INIS)

    McBride, Corrin E.; Machamer, Carolyn E.

    2010-01-01

    Coronaviruses are enveloped RNA viruses that generally cause mild disease in humans. However, the recently emerged coronavirus that caused severe acute respiratory syndrome (SARS-CoV) is the most pathogenic human coronavirus discovered to date. The SARS-CoV spike (S) protein mediates virus entry by binding cellular receptors and inducing fusion between the viral envelope and the host cell membrane. Coronavirus S proteins are palmitoylated, which may affect function. Here, we created a non-palmitoylated SARS-CoV S protein by mutating all nine cytoplasmic cysteine residues. Palmitoylation of SARS-CoV S was required for partitioning into detergent-resistant membranes and for cell-cell fusion. Surprisingly, however, palmitoylation of S was not required for interaction with SARS-CoV M protein. This contrasts with the requirement for palmitoylation of mouse hepatitis virus S protein for interaction with M protein and may point to important differences in assembly and infectivity of these two coronaviruses.

  19. Painful Lytic Lesions of the Foot : A Case Report

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    R Vaishya

    2015-03-01

    Full Text Available The presence of lytic lesions in the bones of foot raises a number of diagnostic possibilities ranging from infection, inflammatory pathology to neoplastic conditions. Although the radiological picture is not pathognomonic of any pathology, clinical history and histopathological examination can help to clinch the diagnosis. We present a case of multiple lytic lesions of the foot and discuss possible differential diagnoses. The patient was diagnosed as a case of madura foot and the lesions responded to surgical debridement and anti-fungal treatment with a good functional outcome. Madura foot is an uncommon, chronic granulomatous fungal or bacterial infection with a predilection in people who walk barefoot. Although known for a specific geographical distribution, madura foot should be kept as a possible diagnosis in patients presenting with lytic lesions of the foot due to population emigration across the world.

  20. Palmitoylation as a Functional Regulator of Neurotransmitter Receptors

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    Vladimir S. Naumenko

    2018-01-01

    Full Text Available The majority of neuronal proteins involved in cellular signaling undergo different posttranslational modifications significantly affecting their functions. One of these modifications is a covalent attachment of a 16-C palmitic acid to one or more cysteine residues (S-palmitoylation within the target protein. Palmitoylation is a reversible modification, and repeated cycles of palmitoylation/depalmitoylation might be critically involved in the regulation of multiple signaling processes. Palmitoylation also represents a common posttranslational modification of the neurotransmitter receptors, including G protein-coupled receptors (GPCRs and ligand-gated ion channels (LICs. From the functional point of view, palmitoylation affects a wide span of neurotransmitter receptors activities including their trafficking, sorting, stability, residence lifetime at the cell surface, endocytosis, recycling, and synaptic clustering. This review summarizes the current knowledge on the palmitoylation of neurotransmitter receptors and its role in the regulation of receptors functions as well as in the control of different kinds of physiological and pathological behavior.

  1. Isolation and Characterization of a Lytic Bacteriophage (vB_PmiS-TH) and Its Application in Combination with Ampicillin against Planktonic and Biofilm Forms of Proteus mirabilis Isolated from Urinary Tract Infection.

    Science.gov (United States)

    Yazdi, Mahsa; Bouzari, Majid; Ghaemi, Ezzat Allah

    2018-01-01

    Proteus mirabilis is one of the most common causes of urinary tract infection (UTI), particularly in patients undergoing long-term catheterization. Phage vB_PmiS-TH was isolated from wastewater with high lytic activity against P. mirabilis (TH) isolated from UTI. The phage had rapid adsorption, a large burst size (∼260 PFU per infected cell), and high stability at a wide range of temperatures and pH values. As analyzed by transmission electron microscopy, phage vB_PmiS-TH had an icosahedral head of ∼87 × 62 nm with a noncontractile tail about 137 nm in length and 11 nm in width. It belongs to the family Siphoviridae. Combination of the phage vB_PmiS-TH with ampicillin had a higher removal activity against planktonic cells of P. mirabilis (TH) than the phage or the antibiotic alone. Combination of the phage at a multiplicity of infection of 100 with a high dose of ampicillin (246 µg/mL) showed the highest biofilm removal activity after 24 h. This study demonstrates that using a combination of phage and antibiotic could be significantly more effective against planktonic and biofilm forms of P. mirabilis (TH). © 2018 S. Karger AG, Basel.

  2. Niclosamide inhibits lytic replication of Epstein-Barr virus by disrupting mTOR activation.

    Science.gov (United States)

    Huang, Lu; Yang, Mengtian; Yuan, Yan; Li, Xiaojuan; Kuang, Ersheng

    2017-02-01

    Infection with the oncogenic γ-herpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause several severe malignancies in humans. Inhibition of the lytic replication of EBV and KSHV eliminates the reservoir of persistent infection and transmission, consequently preventing the occurrence of diseases from the sources of infection. Antiviral drugs are limited in controlling these viral infectious diseases. Here, we demonstrate that niclosamide, an old anthelmintic drug, inhibits mTOR activation during EBV lytic replication. Consequently, niclosamide effectively suppresses EBV lytic gene expression, viral DNA lytic replication and virion production in EBV-infected lymphoma cells and epithelial cells. Niclosamide exhibits cytotoxicity toward lymphoma cells and induces irreversible cell cycle arrest in lytically EBV-infected cells. The ectopic overexpression of mTOR reverses the inhibition of niclosamide in EBV lytic replication. Similarly, niclosamide inhibits KSHV lytic replication. Thus, we conclude that niclosamide is a promising candidate for chemotherapy against the acute occurrence and transmission of infectious diseases of oncogenic γ-herpesviruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. The complete genomic sequence of lytic bacteriophage gh-1 infecting Pseudomonas putida--evidence for close relationship to the T7 group

    International Nuclear Information System (INIS)

    Kovalyova, Irina V.; Kropinski, Andrew M.

    2003-01-01

    The genome of the lytic Pseudomonas putida bacteriophage gh-1 is linear double-stranded DNA containing 37,359 bp with 216-bp direct terminal repeats. Like other members of the T7 group, the gh-1 genome contains regions of high homology to T7 interspersed with nonhomologous regions that contain small open reading frames of unknown function. The genome shares 31 genes in common with other members of the T7 group, including RNA polymerase, and an additional 12 unique putative genes. A major difference between gh-1 and other members of this group is the absence of any open reading frames between the left direct terminal repeat and gene 1. Sequence analysis of the gh-1 genome also revealed the presence of 10 putative phage promoters with a consensus sequence similar to the promoters of T3 and phiYeO3-12 (consensus: TAAAAACCCTCACTRTGGCHSCM). P. putida mutants resistant to gh-1 were demonstrated to have an altered lipopolysaccharide structure, indicating that members of this group use lipopolysaccharide as their cellular receptor

  4. Specific proteins synthesized during the viral lytic cycle in vaccinia virus-infected HeLa cells: analysis by high-resolution, two-dimensional gel electrophoresis

    International Nuclear Information System (INIS)

    Carrasco, L.; Bravo, R.

    1986-01-01

    The proteins synthesized in vaccinia-infected HeLa cells have been analyzed at different times after infection by using two-dimensional gel electrophoresis. Vaccinia-infected cells present up to 198 polypeptides (138 acidic, isoelectric focusing; 60 basic, nonequilibrium pH gradient electrophoresis) not detected in control cells. Cells infected in the presence of cycloheximide show 81 additional polypeptides after cycloheximide removal, resulting in a total estimate of 279 proteins induced after vaccinia infection. The glycoproteins made at various time postinfection were also analyzed. At least 13 proteins labeled with [ 3 H]glucosamine were detected in vaccinia-infected HeLa cells

  5. La dicotomía de los virus polioma: ¿Infección lítica o inducción de neoplasias? The paradox of polyomaviruses Lytic infection or tumor induction?

    Directory of Open Access Journals (Sweden)

    Norberto A. Sanjuan

    2004-02-01

    Full Text Available Los virus Polioma murinos provocan infecciones líticas en cultivos de células de ratón y transforman in vitro células de rata a través de la interacción de su oncogén mT con diversos reguladores celulares. Luego de su inoculación en ratones neonatos inducen neoplasias epiteliales y mesenquimáticas. Se ha propuesto que las cepas de polioma más oncogénicas son aquellas que previamente replican más en el ratón. Sin embargo, a nivel de una sola célula la infección lítica y la transformación deberían ser mutuamente excluyentes. En cada neoplasia han sido descriptos 3 tipos celulares según expresen el DNA viral solo o concomitantemente con la proteína mayor de la cápside VP1, o que no contengan DNA viral ni VP-1. En nuestro laboratorio detectamos la existencia de un cuarto tipo celular en las neoplasias, en el que se expresa la totalidad del genoma viral pero no ocurre el ensamblaje, probablemente por alteraciones en la fosforilación de VP-1. Se discuten los mecanismos de migración intracelular de Polioma, la diseminación en el ratón y los factores que podrían estar involucrados en la inducción de neoplasias o en la infección lítica inducidas por el virus.Murine polyomaviruses can produce lytic infections in mouse cell cultures or transform in vitro rat fibroblasts through a complex interaction with key cellular regulators. After infection of newborn mice, some strains of polyomavirus induce epithelial and mesenchymal tumors. It has been described that there is a direct relationship between viral dissemination in the mouse and tumor induction. However, at a single cell level lytic infection and transformation would not be able to coexist. The existence of 3 distinct cell populations in polyoma-induced tumors, classified according to the presence or absence of viral DNA and viral capsid protein VP-1 have been described. We have reported a fourth type of cell in the neoplasms, that can express the early and the late viral

  6. [Potentialization of antibiotics by lytic enzymes].

    Science.gov (United States)

    Brisou, J; Babin, P; Babin, R

    1975-01-01

    Few lytic enzymes, specially papaine and lysozyme, acting on the membrane and cell wall structures facilitate effects of bacitracine, streptomycine and other antibiotics. Streptomycino resistant strains became sensibles to this antibiotic after contact with papaine and lysozyme. The results of tests in physiological suspensions concern only the lytic activity of enzymes. The results on nutrient medium concern together lytic, and antibiotic activities.

  7. Palmitoylated APP Forms Dimers, Cleaved by BACE1.

    Directory of Open Access Journals (Sweden)

    Raja Bhattacharyya

    Full Text Available A major rate-limiting step for Aβ generation and deposition in Alzheimer's disease brains is BACE1-mediated cleavage (β-cleavage of the amyloid precursor protein (APP. We previously reported that APP undergoes palmitoylation at two cysteine residues (Cys186 and Cys187 in the E1-ectodomain. 8-10% of total APP is palmitoylated in vitro and in vivo. Palmitoylated APP (palAPP shows greater preference for β-cleavage than total APP in detergent resistant lipid rafts. Protein palmitoylation is known to promote protein dimerization. Since dimerization of APP at its E1-ectodomain results in elevated BACE1-mediated cleavage of APP, we have now investigated whether palmitoylation of APP affects its dimerization and whether this leads to elevated β-cleavage of the protein. Here we report that over 90% of palAPP is dimerized while only ~20% of total APP forms dimers. PalAPP-dimers are predominantly cis-oriented while total APP dimerizes in both cis- and trans-orientation. PalAPP forms dimers 4.5-times more efficiently than total APP. Overexpression of the palmitoylating enzymes DHHC7 and DHHC21 that increase palAPP levels and Aβ release, also increased APP dimerization in cells. Conversely, inhibition of APP palmitoylation by pharmacological inhibitors reduced APP-dimerization in coimmunoprecipitation and FLIM/FRET assays. Finally, in vitro BACE1-activity assays demonstrate that palmitoylation-dependent dimerization of APP promotes β-cleavage of APP in lipid-rich detergent resistant cell membranes (DRMs, when compared to total APP. Most importantly, generation of sAPPβ-sAPPβ dimers is dependent on APP-palmitoylation while total sAPPβ generation is not. Since BACE1 shows preference for palAPP dimers over total APP, palAPP dimers may serve as novel targets for effective β-cleavage inhibitors of APP as opposed to BACE1 inhibitors.

  8. Reactivation and Lytic Replication of Kaposi’s Sarcoma-Associated Herpesvirus: An Update

    Science.gov (United States)

    Aneja, Kawalpreet K.; Yuan, Yan

    2017-01-01

    The life cycle of Kaposi’s sarcoma-associated herpesvirus (KSHV) consists of two phases, latent and lytic. The virus establishes latency as a strategy for avoiding host immune surveillance and fusing symbiotically with the host for lifetime persistent infection. However, latency can be disrupted and KSHV is reactivated for entry into the lytic replication. Viral lytic replication is crucial for efficient dissemination from its long-term reservoir to the sites of disease and for the spread of the virus to new hosts. The balance of these two phases in the KSHV life cycle is important for both the virus and the host and control of the switch between these two phases is extremely complex. Various environmental factors such as oxidative stress, hypoxia, and certain chemicals have been shown to switch KSHV from latency to lytic reactivation. Immunosuppression, unbalanced inflammatory cytokines, and other viral co-infections also lead to the reactivation of KSHV. This review article summarizes the current understanding of the initiation and regulation of KSHV reactivation and the mechanisms underlying the process of viral lytic replication. In particular, the central role of an immediate-early gene product RTA in KSHV reactivation has been extensively investigated. These studies revealed multiple layers of regulation in activation of RTA as well as the multifunctional roles of RTA in the lytic replication cascade. Epigenetic regulation is known as a critical layer of control for the switch of KSHV between latency and lytic replication. The viral non-coding RNA, PAN, was demonstrated to play a central role in the epigenetic regulation by serving as a guide RNA that brought chromatin remodeling enzymes to the promoters of RTA and other lytic genes. In addition, a novel dimension of regulation by microPeptides emerged and has been shown to regulate RTA expression at the protein level. Overall, extensive investigation of KSHV reactivation and lytic replication has revealed

  9. Targeting Palmitoyl Acyltransferases in Mutant NRAS-Driven Melanoma

    Science.gov (United States)

    2015-10-01

    Palmitoylation: policing protein stability and traffic . Nat. Rev. Mol. Cell Biol. 8, 74−84. (2) Resh, M. D. (2006) Palmitoylation of ligands, receptors...vector (EMD Biosciences) that included a C-terminal His6-tag. The construct was veri- fied by DNA sequencing. The pET29-TEAD2217–447 plasmid was...were performed successfully at least 3 independent times. No samples or animal were excluded from the analysis. The investigators were not blinded to

  10. Preclinical Testing of an Oncolytic Parvovirus in Ewing Sarcoma: Protoparvovirus H-1 Induces Apoptosis and Lytic Infection In Vitro but Fails to Improve Survival In Vivo.

    Science.gov (United States)

    Lacroix, Jeannine; Kis, Zoltán; Josupeit, Rafael; Schlund, Franziska; Stroh-Dege, Alexandra; Frank-Stöhr, Monika; Leuchs, Barbara; Schlehofer, Jörg R; Rommelaere, Jean; Dinsart, Christiane

    2018-06-03

    About 70% of all Ewing sarcoma (EWS) patients are diagnosed under the age of 20 years. Over the last decades little progress has been made towards finding effective treatment approaches for primarily metastasized or refractory Ewing sarcoma in young patients. Here, in the context of the search for novel therapeutic options, the potential of oncolytic protoparvovirus H-1 (H-1PV) to treat Ewing sarcoma was evaluated, its safety having been proven previously tested in adult cancer patients and its oncolytic efficacy demonstrated on osteosarcoma cell cultures. The effects of viral infection were tested in vitro on four human Ewing sarcoma cell lines. Notably evaluated were effects of the virus on the cell cycle and its replication efficiency. Within 24 h after infection, the synthesis of viral proteins was induced. Efficient H-1PV replication was confirmed in all four Ewing sarcoma cell lines. The cytotoxicity of the virus was determined on the basis of cytopathic effects, cell viability, and cell lysis. These in vitro experiments revealed efficient killing of Ewing sarcoma cells by H-1PV at a multiplicity of infection between 0.1 and 5 plaque forming units (PFU)/cell. In two of the four tested cell lines, significant induction of apoptosis by H-1PV was observed. H-1PV thus meets all the in vitro criteria for a virus to be oncolytic towards Ewing sarcoma. In the first xenograft experiments, however, although an antiproliferative effect of intratumoral H-1PV injection was observed, no significant improvement of animal survival was noted. Future projects aiming to validate parvovirotherapy for the treatment of pediatric Ewing sarcoma should focus on combinatorial treatments and will require the use of patient-derived xenografts and immunocompetent syngeneic animal models.

  11. Preclinical Testing of an Oncolytic Parvovirus in Ewing Sarcoma: Protoparvovirus H-1 Induces Apoptosis and Lytic Infection In Vitro but Fails to Improve Survival In Vivo

    Directory of Open Access Journals (Sweden)

    Jeannine Lacroix

    2018-06-01

    Full Text Available About 70% of all Ewing sarcoma (EWS patients are diagnosed under the age of 20 years. Over the last decades little progress has been made towards finding effective treatment approaches for primarily metastasized or refractory Ewing sarcoma in young patients. Here, in the context of the search for novel therapeutic options, the potential of oncolytic protoparvovirus H-1 (H-1PV to treat Ewing sarcoma was evaluated, its safety having been proven previously tested in adult cancer patients and its oncolytic efficacy demonstrated on osteosarcoma cell cultures. The effects of viral infection were tested in vitro on four human Ewing sarcoma cell lines. Notably evaluated were effects of the virus on the cell cycle and its replication efficiency. Within 24 h after infection, the synthesis of viral proteins was induced. Efficient H-1PV replication was confirmed in all four Ewing sarcoma cell lines. The cytotoxicity of the virus was determined on the basis of cytopathic effects, cell viability, and cell lysis. These in vitro experiments revealed efficient killing of Ewing sarcoma cells by H-1PV at a multiplicity of infection between 0.1 and 5 plaque forming units (PFU/cell. In two of the four tested cell lines, significant induction of apoptosis by H-1PV was observed. H-1PV thus meets all the in vitro criteria for a virus to be oncolytic towards Ewing sarcoma. In the first xenograft experiments, however, although an antiproliferative effect of intratumoral H-1PV injection was observed, no significant improvement of animal survival was noted. Future projects aiming to validate parvovirotherapy for the treatment of pediatric Ewing sarcoma should focus on combinatorial treatments and will require the use of patient-derived xenografts and immunocompetent syngeneic animal models.

  12. Palmitoylation regulates epidermal homeostasis and hair follicle differentiation.

    Directory of Open Access Journals (Sweden)

    Pleasantine Mill

    2009-11-01

    Full Text Available Palmitoylation is a key post-translational modification mediated by a family of DHHC-containing palmitoyl acyl-transferases (PATs. Unlike other lipid modifications, palmitoylation is reversible and thus often regulates dynamic protein interactions. We find that the mouse hair loss mutant, depilated, (dep is due to a single amino acid deletion in the PAT, Zdhhc21, resulting in protein mislocalization and loss of palmitoylation activity. We examined expression of Zdhhc21 protein in skin and find it restricted to specific hair lineages. Loss of Zdhhc21 function results in delayed hair shaft differentiation, at the site of expression of the gene, but also leads to hyperplasia of the interfollicular epidermis (IFE and sebaceous glands, distant from the expression site. The specific delay in follicle differentiation is associated with attenuated anagen propagation and is reflected by decreased levels of Lef1, nuclear beta-catenin, and Foxn1 in hair shaft progenitors. In the thickened basal compartment of mutant IFE, phospho-ERK and cell proliferation are increased, suggesting increased signaling through EGFR or integrin-related receptors, with a parallel reduction in expression of the key differentiation factor Gata3. We show that the Src-family kinase, Fyn, involved in keratinocyte differentiation, is a direct palmitoylation target of Zdhhc21 and is mislocalized in mutant follicles. This study is the first to demonstrate a key role for palmitoylation in regulating developmental signals in mammalian tissue homeostasis.

  13. Drug Modulators of B Cell Signaling Pathways and Epstein-Barr Virus Lytic Activation.

    Science.gov (United States)

    Kosowicz, John G; Lee, Jaeyeun; Peiffer, Brandon; Guo, Zufeng; Chen, Jianmeng; Liao, Gangling; Hayward, S Diane; Liu, Jun O; Ambinder, Richard F

    2017-08-15

    Epstein-Barr virus (EBV) is a ubiquitous human gammaherpesvirus that establishes a latency reservoir in B cells. In this work, we show that ibrutinib, idelalisib, and dasatinib, drugs that block B cell receptor (BCR) signaling and are used in the treatment of hematologic malignancies, block BCR-mediated lytic induction at clinically relevant doses. We confirm that the immunosuppressive drugs cyclosporine and tacrolimus also inhibit BCR-mediated lytic induction but find that rapamycin does not inhibit BCR-mediated lytic induction. Further investigation shows that mammalian target of rapamycin complex 2 (mTORC2) contributes to BCR-mediated lytic induction and that FK506-binding protein 12 (FKBP12) binding alone is not adequate to block activation. Finally, we show that BCR signaling can activate EBV lytic induction in freshly isolated B cells from peripheral blood mononuclear cells (PBMCs) and that activation can be inhibited by ibrutinib or idelalisib. IMPORTANCE EBV establishes viral latency in B cells. Activation of the B cell receptor pathway activates lytic viral expression in cell lines. Here we show that drugs that inhibit important kinases in the BCR signaling pathway inhibit activation of lytic viral expression but do not inhibit several other lytic activation pathways. Immunosuppressant drugs such as cyclosporine and tacrolimus but not rapamycin also inhibit BCR-mediated EBV activation. Finally, we show that BCR activation of lytic infection occurs not only in tumor cell lines but also in freshly isolated B cells from patients and that this activation can be blocked by BCR inhibitors. Copyright © 2017 American Society for Microbiology.

  14. Potential of a lytic bacteriophage to disrupt Acinetobacter baumannii biofilms in vitro.

    Science.gov (United States)

    Liu, Yannan; Mi, Zhiqiang; Niu, Wenkai; An, Xiaoping; Yuan, Xin; Liu, Huiying; Wang, Yong; Feng, Yuzhong; Huang, Yong; Zhang, Xianglilan; Zhang, Zhiyi; Fan, Hang; Peng, Fan; Li, Puyuan; Tong, Yigang; Bai, Changqing

    2016-10-01

    The ability of Acinetobacter baumannii to form biofilms and develop antibiotic resistance makes it difficult to control infections caused by this bacterium. In this study, we explored the potential of a lytic bacteriophage to disrupt A. baumannii biofilms. The potential of the lytic bacteriophage to disrupt A. baumannii biofilms was assessed by performing electron microscopy, live/dead bacterial staining, crystal violet staining and by determining adenosine triphosphate release. The bacteriophage inhibited the formation of and disrupted preformed A. baumannii biofilms. Results of disinfection assay showed that the lytic bacteriophage lysed A. baumannii cells suspended in blood or grown on metal surfaces. These results suggest the potential of the lytic bacteriophage to disrupt A. baumannii biofilms.

  15. Palmitoylation of the Cysteine Residue in the DHHC Motif of a Palmitoyl Transferase Mediates Ca2+ Homeostasis in Aspergillus.

    Directory of Open Access Journals (Sweden)

    Yuanwei Zhang

    2016-04-01

    Full Text Available Finely tuned changes in cytosolic free calcium ([Ca2+]c mediate numerous intracellular functions resulting in the activation or inactivation of a series of target proteins. Palmitoylation is a reversible post-translational modification involved in membrane protein trafficking between membranes and in their functional modulation. However, studies on the relationship between palmitoylation and calcium signaling have been limited. Here, we demonstrate that the yeast palmitoyl transferase ScAkr1p homolog, AkrA in Aspergillus nidulans, regulates [Ca2+]c homeostasis. Deletion of akrA showed marked defects in hyphal growth and conidiation under low calcium conditions which were similar to the effects of deleting components of the high-affinity calcium uptake system (HACS. The [Ca2+]c dynamics in living cells expressing the calcium reporter aequorin in different akrA mutant backgrounds were defective in their [Ca2+]c responses to high extracellular Ca2+ stress or drugs that cause ER or plasma membrane stress. All of these effects on the [Ca2+]c responses mediated by AkrA were closely associated with the cysteine residue of the AkrA DHHC motif, which is required for palmitoylation by AkrA. Using the acyl-biotin exchange chemistry assay combined with proteomic mass spectrometry, we identified protein substrates palmitoylated by AkrA including two new putative P-type ATPases (Pmc1 and Spf1 homologs, a putative proton V-type proton ATPase (Vma5 homolog and three putative proteins in A. nidulans, the transcripts of which have previously been shown to be induced by extracellular calcium stress in a CrzA-dependent manner. Thus, our findings provide strong evidence that the AkrA protein regulates [Ca2+]c homeostasis by palmitoylating these protein candidates and give new insights the role of palmitoylation in the regulation of calcium-mediated responses to extracellular, ER or plasma membrane stress.

  16. ZDHHC3 Tyrosine Phosphorylation Regulates Neural Cell Adhesion Molecule Palmitoylation

    Science.gov (United States)

    Lievens, Patricia Marie-Jeanne; Kuznetsova, Tatiana; Kochlamazashvili, Gaga; Cesca, Fabrizia; Gorinski, Natalya; Galil, Dalia Abdel; Cherkas, Volodimir; Ronkina, Natalia; Lafera, Juri; Gaestel, Matthias

    2016-01-01

    The neural cell adhesion molecule (NCAM) mediates cell-cell and cell-matrix adhesion. It is broadly expressed in the nervous system and regulates neurite outgrowth, synaptogenesis, and synaptic plasticity. Previous in vitro studies revealed that palmitoylation of NCAM is required for fibroblast growth factor 2 (FGF2)-stimulated neurite outgrowth and identified the zinc finger DHHC (Asp-His-His-Cys)-containing proteins ZDHHC3 and ZDHHC7 as specific NCAM-palmitoylating enzymes. Here, we verified that FGF2 controlled NCAM palmitoylation in vivo and investigated molecular mechanisms regulating NCAM palmitoylation by ZDHHC3. Experiments with overexpression and pharmacological inhibition of FGF receptor (FGFR) and Src revealed that these kinases control tyrosine phosphorylation of ZDHHC3 and that ZDHHC3 is phosphorylated by endogenously expressed FGFR and Src proteins. By site-directed mutagenesis, we found that Tyr18 is an FGFR1-specific ZDHHC3 phosphorylation site, while Tyr295 and Tyr297 are specifically phosphorylated by Src kinase in cell-based and cell-free assays. Abrogation of tyrosine phosphorylation increased ZDHHC3 autopalmitoylation, enhanced interaction with NCAM, and upregulated NCAM palmitoylation. Expression of ZDHHC3 with tyrosine mutated in cultured hippocampal neurons promoted neurite outgrowth. Our findings for the first time highlight that FGFR- and Src-mediated tyrosine phosphorylation of ZDHHC3 modulates ZDHHC3 enzymatic activity and plays a role in neuronal morphogenesis. PMID:27247265

  17. Palmitoylation of POTE family proteins for plasma membrane targeting

    International Nuclear Information System (INIS)

    Das, Sudipto; Ise, Tomoko; Nagata, Satoshi; Maeda, Hiroshi; Bera, Tapan K.; Pastan, Ira

    2007-01-01

    The POTE gene family is composed of 13 paralogs and likely evolved by duplications and remodeling of the human genome. One common property of POTE proteins is their localization on the inner aspect of the plasma membrane. To determine the structural elements required for membrane localization, we expressed mutants of different POTEs in 293T cells as EGFP fusion proteins. We also tested their palmitoylation by a biotin-switch assay. Our data indicate that the membrane localizations of different POTEs are mediated by similar 3-4 short cysteine rich repeats (CRRs) near the amino-terminuses and that palmitoylation on paired cysteine residues in each CRR motif is responsible for the localization. Multiple palmitoylation in the small CRRs can result in the strong association of whole POTEs with plasma membrane

  18. The Lytic SA Phage Demonstrate Bactericidal Activity against Mastitis Causing Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hamza Ameer

    2016-01-01

    Full Text Available Staphylococcus aureus is the major causative agent of mastitis among dairy animals as it causes intramammary gland infection. Due to antibiotic resistance and contamination of antibiotics in the milk of diseased animals; alternative therapeutic agents are required to cure mastitis. Lytic bacteriophages and their gene products can be potential therapeutic agents against bacteria as they are host specific and less harmful than antibiotics. In this study, Staphylococcus aureus were isolated from milk samples of the infected animals and identified biochemically. SA phage was isolated from sewage water showing lytic activity against Staphylococcus aureus isolates. The highest lytic activity of bacteriophages was observed at 37°C and pH 7, and the most suitable storage condition was at 4°C. SA phage efficiently reduced bacterial growth in the bacterial reduction assay. The characterization and bacterial growth reduction activity of the bacteriophages against Staphylococcus aureus signifies their underlying potential of phage therapy against mastitis.

  19. Toxicity of palmitoyl glycerol to mice: depression of thyroid function

    International Nuclear Information System (INIS)

    Trumbo, P.R.; Meuten, D.J.; King, M.W.; Tove, S.B.

    1987-01-01

    Mice given propylthiouracil, a thyroid inhibitor, and fed a diet containing a nontoxic level of rac-1(3)-palmitoyl glycerol showed the hypothermia and mortality expected for a toxic dose, but did not show these signs when linoleate or oleate was added to the diet. Loss of radioiodine from the whole animal and thyroid gland was slower when mice were fed the toxic palmitoyl glycerol diet than when fed the same diet containing 4% safflower oil. However, mice fed the two diets did not differ in the extent of the incorporation of radioiodine, and essentially all was bound to protein in each case. Follicular thyroid cells from mice fed the potentially toxic diet that contained unsaturated fat were normal in appearance. Conversely, cells from mice fed the toxic diet were smaller and more densely stained, showing evidence of glycoprotein inside the cell. These findings show that the thyroid gland is affected by the palmitoyl glycerol diet. However, the thyroid is not the only organ affected, because giving either thyroxine or triiodothyronine had no effect on the toxicity of palmitoyl glycerol

  20. Bacteriophage lytic to Desulfovibrio aespoeensis isolated from deep groundwater.

    Science.gov (United States)

    Eydal, Hallgerd S C; Jägevall, Sara; Hermansson, Malte; Pedersen, Karsten

    2009-10-01

    Viruses were earlier found to be 10-fold more abundant than prokaryotes in deep granitic groundwater at the Aspö Hard Rock Laboratory (HRL). Using a most probable number (MPN) method, 8-30 000 cells of sulphate-reducing bacteria per ml were found in groundwater from seven boreholes at the Aspö HRL. The content of lytic phages infecting the indigenous bacterium Desulfovibrio aespoeensis in Aspö groundwater was analysed using the MPN technique for phages. In four of 10 boreholes, 0.2-80 phages per ml were found at depths of 342-450 m. Isolates of lytic phages were made from five cultures. Using transmission electron microscopy, these were characterized and found to be in the Podoviridae morphology group. The isolated phages were further analysed regarding host range and were found not to infect five other species of Desulfovibrio or 10 Desulfovibrio isolates with up to 99.9% 16S rRNA gene sequence identity to D. aespoeensis. To further analyse phage-host interactions, using a direct count method, growth of the phages and their host was followed in batch cultures, and the viral burst size was calculated to be approximately 170 phages per lytic event, after a latent period of approximately 70 h. When surviving cells from infected D. aespoeensis batch cultures were inoculated into new cultures and reinfected, immunity to the phages was found. The parasite-prey system found implies that viruses are important for microbial ecosystem diversity and activity, and for microbial numbers in deep subsurface groundwater.

  1. New insights into the posttranslational regulation of human cytosolic thioredoxin by S-palmitoylation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhiyu; Zhong, Liangwei, E-mail: liazho@ucas.ac.cn

    2015-05-15

    High level of palmitate is associated with metabolic disorders. We recently showed that enhanced level of S-palmitoylated cytosolic thioredoxin (Trx1) in mouse liver was new characteristic feature of insulin resistance. However, our understanding of the effect of S-palmitoylation on Trx1 is limited, and the tissue specificity of Trx1 S-palmitoylation is unclear. Here we show that S-palmitoylation also occurs at Cys73 of Trx1 in living endothelial cells, and the level of S-palmitoylated Trx1 undergoes regulation by insulin signaling. Trx1 prefers thiol-thioester exchange with palmitoyl-CoA to acetyl-CoA. S-palmitoylation alters conformation or secondary structure of Trx1, as well as decreases the ability of Trx1 to transfer electrons from thioredoxin reductase to S-nitrosylated protein–tyrosine phosphatase 1B and S-nitroso-glutathione. Our results demonstrate that S-palmitoylation is an important post-translational modification of human Trx1. - Highlights: • S-palmitoylation occurs at Cys73 of Trx1 in living endothelial cells. • Insulin signaling may regulate level of S-palmitoylated Trx1 in the cells. • S-palmitoylation plays significant effects on Trx1 structure and functions.

  2. Hemoglobin is a co-factor of human trypanosome lytic factor

    DEFF Research Database (Denmark)

    Widener, Justin; Nielsen, Marianne Jensby; Shiflett, April

    2007-01-01

    Trypanosome lytic factor (TLF) is a high-density lipoprotein (HDL) subclass providing innate protection to humans against infection by the protozoan parasite Trypanosoma brucei brucei. Two primate-specific plasma proteins, haptoglobin-related protein (Hpr) and apolipoprotein L-1 (ApoL-1), have be...

  3. Phenoloxidase but not lytic activity reflects resistance against Pasteuria ramosa in Daphnia magna.

    Science.gov (United States)

    Pauwels, Kevin; De Meester, Luc; Decaestecker, Ellen; Stoks, Robby

    2011-02-23

    The field of ecological immunology strongly relies on indicators of immunocompetence. Two major indicators in invertebrates, the activity of phenoloxidase (PO) and lytic activity have recently been questioned in studies showing that, across a natural range of baseline levels, these indicators did not predict resistance against a manipulated challenge with natural parasites. We confirmed this finding by showing that baseline levels of PO and lytic activity in the host Daphnia magna were not related to spore load of the parasite Pasteuria ramosa. Yet, PO levels in infected hosts did predict spore load, indicating PO activity can be useful as an indicator of immunocompetence in this model parasite-host system.

  4. Discovery and characterization of inhibitors of human palmitoyl acyltransferases.

    Science.gov (United States)

    Ducker, Charles E; Griffel, Lindsay K; Smith, Ryan A; Keller, Staci N; Zhuang, Yan; Xia, Zuping; Diller, John D; Smith, Charles D

    2006-07-01

    The covalent attachment of palmitate to specific proteins by the action of palmitoyl acyltransferases (PAT) plays critical roles in the biological activities of several oncoproteins. Two PAT activities are expressed by human cells: type 1 PATs that modify the farnesyl-dependent palmitoylation motif found in H- and N-Ras, and type 2 PATs that modify the myristoyl-dependent palmitoylation motif found in the Src family of tyrosine kinases. We have previously shown that the type 1 PAT HIP14 causes cellular transformation. In the current study, we show that mRNA encoding HIP14 is up-regulated in a number of types of human tumors. To assess the potential of HIP14 and other PATs as targets for new anticancer drugs, we developed three cell-based assays suitable for high-throughput screening to identify inhibitors of these enzymes. Using these screens, five chemotypes, with activity toward either type 1 or type 2 PAT activity, were identified. The activity of the hits were confirmed using assays that quantify the in vitro inhibition of PAT activity, as well as a cell-based assay that determines the abilities of the compounds to prevent the localization of palmitoylated green fluorescent proteins to the plasma membrane. Representative compounds from each chemotype showed broad antiproliferative activity toward a panel of human tumor cell lines and inhibited the growth of tumors in vivo. Together, these data show that PATs, and HIP14 in particular, are interesting new targets for anticancer compounds, and that small molecules with such activity can be identified by high-throughput screening.

  5. Endoplasmic reticulum stress causes EBV lytic replication.

    Science.gov (United States)

    Taylor, Gwen Marie; Raghuwanshi, Sandeep K; Rowe, David T; Wadowsky, Robert M; Rosendorff, Adam

    2011-11-17

    Endoplasmic reticulum (ER) stress triggers a homeostatic cellular response in mammalian cells to ensure efficient folding, sorting, and processing of client proteins. In lytic-permissive lymphoblastoid cell lines (LCLs), pulse exposure to the chemical ER-stress inducer thapsigargin (TG) followed by recovery resulted in the activation of the EBV immediate-early (BRLF1, BZLF1), early (BMRF1), and late (gp350) genes, gp350 surface expression, and virus release. The protein phosphatase 1 a (PP1a)-specific phosphatase inhibitor Salubrinal (SAL) synergized with TG to induce EBV lytic genes; however, TG treatment alone was sufficient to activate EBV lytic replication. SAL showed ER-stress-dependent and -independent antiviral effects, preventing virus release in human LCLs and abrogating gp350 expression in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated B95-8 cells. TG resulted in sustained BCL6 but not BLIMP1 or CD138 expression, which is consistent with maintenance of a germinal center B-cell, rather than plasma-cell, phenotype. Microarray analysis identified candidate genes governing lytic replication in LCLs undergoing ER stress.

  6. Isolation of lytic bacteriophage against Vibrio harveyi.

    Science.gov (United States)

    Crothers-Stomps, C; Høj, L; Bourne, D G; Hall, M R; Owens, L

    2010-05-01

    The isolation of lytic bacteriophage of Vibrio harveyi with potential for phage therapy of bacterial pathogens of phyllosoma larvae from the tropical rock lobster Panulirus ornatus. Water samples from discharge channels and grow-out ponds of a prawn farm in northeastern Australia were enriched for 24 h in a broth containing four V. harveyi strains. The bacteriophage-enriched filtrates were spotted onto bacterial lawns demonstrating that the bacteriophage host range for the samples included strains of V. harveyi, Vibrio campbellii, Vibrio rotiferianus, Vibrio parahaemolyticus and Vibrio proteolyticus. Bacteriophage were isolated from eight enriched samples through triple plaque purification. The host range of purified phage included V. harveyi, V. campbellii, V. rotiferianus and V. parahaemolyticus. Transmission electron microscope examination revealed that six purified phage belonged to the family Siphoviridae, whilst two belonged to the family Myoviridae. The Myoviridae appeared to induce bacteriocin production in a limited number of host bacterial strains, suggesting that they were lysogenic rather than lytic. A purified Siphoviridae phage could delay the entry of a broth culture of V. harveyi strain 12 into exponential growth, but could not prevent the overall growth of the bacterial strain. Bacteriophage with lytic activity against V. harveyi were isolated from prawn farm samples. Purified phage of the family Siphoviridae had a clear lytic ability and no apparent transducing properties, indicating they are appropriate for phage therapy. Phage resistance is potentially a major constraint to the use of phage therapy in aquaculture as bacteria are not completely eliminated. Phage therapy is emerging as a potential antibacterial agent that can be used to control pathogenic bacteria in aquaculture systems. The development of phage therapy for aquaculture requires initial isolation and determination of the bacteriophage host range, with subsequent creation of

  7. Endoplasmic reticulum stress causes EBV lytic replication

    OpenAIRE

    Taylor, Gwen Marie; Raghuwanshi, Sandeep K.; Rowe, David T.; Wadowsky, Robert M.; Rosendorff, Adam

    2011-01-01

    Endoplasmic reticulum (ER) stress triggers a homeostatic cellular response in mammalian cells to ensure efficient folding, sorting, and processing of client proteins. In lytic-permissive lymphoblastoid cell lines (LCLs), pulse exposure to the chemical ER-stress inducer thapsigargin (TG) followed by recovery resulted in the activation of the EBV immediate-early (BRLF1, BZLF1), early (BMRF1), and late (gp350) genes, gp350 surface expression, and virus release. The protein phosphatase 1 a (PP1a)...

  8. Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Maia Merabishvili

    Full Text Available Based on genotyping and host range, two newly isolated lytic bacteriophages, myovirus vB_AbaM_Acibel004 and podovirus vB_AbaP_Acibel007, active against Acinetobacter baumannii clinical strains, were selected from a new phage library for further characterization. The complete genomes of the two phages were analyzed. Both phages are characterized by broad host range and essential features of potential therapeutic phages, such as short latent period (27 and 21 min, respectively, high burst size (125 and 145, respectively, stability of activity in liquid culture and low frequency of occurrence of phage-resistant mutant bacterial cells. Genomic analysis showed that while Acibel004 represents a novel bacteriophage with resemblance to some unclassified Pseudomonas aeruginosa phages, Acibel007 belongs to the well-characterized genus of the Phikmvlikevirus. The newly isolated phages can serve as potential candidates for phage cocktails to control A. baumannii infections.

  9. Oncogenic Herpesvirus Utilizes Stress-Induced Cell Cycle Checkpoints for Efficient Lytic Replication.

    Directory of Open Access Journals (Sweden)

    Giuseppe Balistreri

    2016-02-01

    Full Text Available Kaposi's sarcoma herpesvirus (KSHV causes Kaposi's sarcoma and certain lymphoproliferative malignancies. Latent infection is established in the majority of tumor cells, whereas lytic replication is reactivated in a small fraction of cells, which is important for both virus spread and disease progression. A siRNA screen for novel regulators of KSHV reactivation identified the E3 ubiquitin ligase MDM2 as a negative regulator of viral reactivation. Depletion of MDM2, a repressor of p53, favored efficient activation of the viral lytic transcription program and viral reactivation. During lytic replication cells activated a p53 response, accumulated DNA damage and arrested at G2-phase. Depletion of p21, a p53 target gene, restored cell cycle progression and thereby impaired the virus reactivation cascade delaying the onset of virus replication induced cytopathic effect. Herpesviruses are known to reactivate in response to different kinds of stress, and our study now highlights the molecular events in the stressed host cell that KSHV has evolved to utilize to ensure efficient viral lytic replication.

  10. Oncogenic Herpesvirus Utilizes Stress-Induced Cell Cycle Checkpoints for Efficient Lytic Replication

    OpenAIRE

    Balistreri, Giuseppe; Viiliainen, Johanna; Turunen, Mikko; Diaz, Raquel; Lyly, Lauri; Pekkonen, Pirita; Rantala, Juha; Ojala, Krista; Sarek, Grzegorz; Teesalu, Mari; Denisova, Oxana; Peltonen, Karita; Julkunen, Ilkka; Varjosalo, Markku; Kainov, Denis

    2016-01-01

    Kaposi?s sarcoma herpesvirus (KSHV) causes Kaposi?s sarcoma and certain lymphoproliferative malignancies. Latent infection is established in the majority of tumor cells, whereas lytic replication is reactivated in a small fraction of cells, which is important for both virus spread and disease progression. A siRNA screen for novel regulators of KSHV reactivation identified the E3 ubiquitin ligase MDM2 as a negative regulator of viral reactivation. Depletion of MDM2, a repressor of p53, favored...

  11. Anti-TNFα therapy for inflammatory bowel diseases is associated with Epstein-Barr virus lytic activation.

    Science.gov (United States)

    Lapsia, Sameer; Koganti, Siva; Spadaro, Salvatore; Rajapakse, Ramona; Chawla, Anupama; Bhaduri-McIntosh, Sumita

    2016-02-01

    Anti-TNFα therapy, known to suppress T-cell immunity, is increasingly gaining popularity for treatment of autoimmune diseases including inflammatory bowel diseases (IBD). T-cell suppression increases the risk of B-cell EBV-lymphoproliferative diseases and lymphomas. Since EBV-lytic activation is essential for development of EBV-lymphomas and there have been reports of EBV-lymphomas in patients treated with anti-TNFα therapy, we investigated if patients treated with anti-TNFα antibodies demonstrate greater EBV-lytic activity in blood. Peripheral blood mononuclear cells from 10 IBD patients solely on anti-TNFα therapy compared to 3 control groups (10 IBD patients not on immunosuppressive therapy, 10 patients with abdominal pain but without IBD, and 10 healthy subjects) were examined for the percentage of T-cells, EBV load and EBV-lytic transcripts. Patients on anti-TNFα therapy had significantly fewer T-cells, greater EBV load, and increased levels of transcripts from EBV-lytic genes of all kinetic classes compared to controls. Furthermore, exposure of EBV-infected B-cell lines to anti-TNFα antibodies resulted in increased levels of BZLF1 mRNA; BZLF1 encodes for ZEBRA, the viral latency-to-lytic cycle switch. Thus, IBD patients treated with anti-TNFα antibodies have greater EBV loads likely due to enhanced EBV-lytic gene expression and anti-TNFα antibodies may be sufficient to activate the EBV lytic cycle. Findings from this pilot study lay the groundwork for additional scientific and clinical investigation into the effects of anti-TNFα therapy on the life cycle of EBV, a ubiquitous oncovirus that causes lymphomas in the setting of immunocompromise. © 2015 Wiley Periodicals, Inc.

  12. Are Phage Lytic Proteins the Secret Weapon To Kill Staphylococcus aureus?

    Directory of Open Access Journals (Sweden)

    Diana Gutiérrez

    2018-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is one of the most threatening microorganisms for global human health. The current strategies to reduce the impact of S. aureus include a restrictive control of worldwide antibiotic use, prophylactic measures to hinder contamination, and the search for novel antimicrobials to treat human and animal infections caused by this bacterium. The last strategy is currently the focus of considerable research. In this regard, phage lytic proteins (endolysins and virion-associated peptidoglycan hydrolases [VAPGHs] have been proposed as suitable candidates. Indeed, these proteins display narrow-spectrum antimicrobial activity and a virtual lack of bacterial-resistance development. Additionally, the therapeutic use of phage lytic proteins in S. aureus animal infection models is yielding promising results, showing good efficacy without apparent side effects. Nonetheless, human clinical trials are still in progress, and data are not available yet. This minireview also analyzes the main obstacles for introducing phage lytic proteins as human therapeutics against S. aureus infections. Besides the common technological problems derived from large-scale production of therapeutic proteins, a major setback is the lack of a proper legal framework regulating their use. In that sense, the relevant health authorities should urgently have a timely discussion about these new antimicrobials. On the other hand, the research community should provide data to dispel any doubts regarding their efficacy and safety. Overall, the appropriate scientific data and regulatory framework will encourage pharmaceutical companies to invest in these promising antimicrobials.

  13. Palmitoylation at Cys574 is essential for MT1-MMP to promote cell migration

    DEFF Research Database (Denmark)

    Anilkumar, Narayanapanicker; Uekita, Takamasa; Couchman, John R

    2005-01-01

    of the palmitoylated cysteine relative to LLY573, a motif that interacts with mu2 subunit of adaptor protein 2, is critical for the cell motility-promoting activity of MT1-MMP and its clathrin-mediated internalization. Taken together, palmitoylation of MT1-MMP is one of the key posttranslational modifications......MT1-MMP is a type I transmembrane proteinase that promotes cell migration and invasion. Here, we report that MT1-MMP is palmitoylated at Cys574 in the cytoplasmic domain, and this lipid modification is critical for its promotion of cell migration and clathrin-mediated internalization...... that determines MT1-MMP-dependent cell migration....

  14. Leflunomide/teriflunomide inhibit Epstein-Barr virus (EBV)- induced lymphoproliferative disease and lytic viral replication.

    Science.gov (United States)

    Bilger, Andrea; Plowshay, Julie; Ma, Shidong; Nawandar, Dhananjay; Barlow, Elizabeth A; Romero-Masters, James C; Bristol, Jillian A; Li, Zhe; Tsai, Ming-Han; Delecluse, Henri-Jacques; Kenney, Shannon C

    2017-07-04

    EBV infection causes mononucleosis and is associated with specific subsets of B cell lymphomas. Immunosuppressed patients such as organ transplant recipients are particularly susceptible to EBV-induced lymphoproliferative disease (LPD), which can be fatal. Leflunomide (a drug used to treat rheumatoid arthritis) and its active metabolite teriflunomide (used to treat multiple sclerosis) inhibit de novo pyrimidine synthesis by targeting the cellular dihydroorotate dehydrogenase, thereby decreasing T cell proliferation. Leflunomide also inhibits the replication of cytomegalovirus and BK virus via both "on target" and "off target" mechanisms and is increasingly used to treat these viruses in organ transplant recipients. However, whether leflunomide/teriflunomide block EBV replication or inhibit EBV-mediated B cell transformation is currently unknown. We show that teriflunomide inhibits cellular proliferation, and promotes apoptosis, in EBV-transformed B cells in vitro at a clinically relevant dose. In addition, teriflunomide prevents the development of EBV-induced lymphomas in both a humanized mouse model and a xenograft model. Furthermore, teriflunomide inhibits lytic EBV infection in vitro both by preventing the initial steps of lytic viral reactivation, and by blocking lytic viral DNA replication. Leflunomide/teriflunomide might therefore be clinically useful for preventing EBV-induced LPD in patients who have high EBV loads yet require continued immunosuppression.

  15. In vivo dynamics of EBNA1-oriP interaction during latent and lytic replication of Epstein-Barr virus.

    Science.gov (United States)

    Daikoku, Tohru; Kudoh, Ayumi; Fujita, Masatoshi; Sugaya, Yutaka; Isomura, Hiroki; Tsurumi, Tatsuya

    2004-12-24

    The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is required for maintenance of the viral genome DNA during the latent phase of EBV replication but continues to be synthesized after the induction of viral productive replication. An EBV genome-wide chromatin immunoprecipitation assay revealed that EBNA1 constantly binds to oriP of the EBV genome during not only latent but also lytic infection. Although the total levels of EBNA1 proved constant throughout the latter, the levels of the oriP-bound form were increased as lytic infection proceeded. EBV productive DNA replication occurs at discrete sites in nuclei, called replication compartments, where viral replication proteins are clustered. Confocal laser microscopic analyses revealed that whereas EBNA1 was distributed broadly in nuclei as fine punctate dots during the latent phase of infection, the protein became redistributed to the viral replication compartments and localized as distinct spots within and/or nearby the compartments after the induction of lytic replication. Taking these findings into consideration, oriP regions of the EBV genome might be organized by EBNA1 into replication domains that may set up scaffolding for lytic replication and transcription.

  16. Assessment of Palmitoyl and Sulphate Conjugated Glycol Chitosan for Development of Polymeric Micelles

    Directory of Open Access Journals (Sweden)

    Ikram Ullah Khan

    2013-06-01

    Full Text Available Introduction: Amphiphilic copolymers are capable of forming core shell-like structures at the critical micellar concentration (CMC; hence, they can serve as drug carriers. Thus, in the present work, polymeric micelles based on novel chitosan derivative were synthesized. Methods: Block copolymer of palmitoyl glycol chitosan sulfate (PGCS was prepared by grafting palmitoyl and sulfate groups serving as hydrophobic and hydrophilic fractions, respectively. Then, fourier transform infrared spectra (FTIR and spectral changes in iodine/iodide mixture were carried out. Results: FTIR studies confirmed the formation of palmitoyl glycol chitosan sulfate (PGCS and spectral changes in iodine/iodide mixture indicated CMC which lies in the range of 0.003-0.2 mg/ml. Conclusion: Therefore, our study indicated that polymeric micelles based on palmitoyl glycol chitosan sulphate could be used as a prospective carrier for water insoluble drugs.

  17. NBA-Palm: prediction of palmitoylation site implemented in Naïve Bayes algorithm

    Directory of Open Access Journals (Sweden)

    Jin Changjiang

    2006-10-01

    Full Text Available Abstract Background Protein palmitoylation, an essential and reversible post-translational modification (PTM, has been implicated in cellular dynamics and plasticity. Although numerous experimental studies have been performed to explore the molecular mechanisms underlying palmitoylation processes, the intrinsic feature of substrate specificity has remained elusive. Thus, computational approaches for palmitoylation prediction are much desirable for further experimental design. Results In this work, we present NBA-Palm, a novel computational method based on Naïve Bayes algorithm for prediction of palmitoylation site. The training data is curated from scientific literature (PubMed and includes 245 palmitoylated sites from 105 distinct proteins after redundancy elimination. The proper window length for a potential palmitoylated peptide is optimized as six. To evaluate the prediction performance of NBA-Palm, 3-fold cross-validation, 8-fold cross-validation and Jack-Knife validation have been carried out. Prediction accuracies reach 85.79% for 3-fold cross-validation, 86.72% for 8-fold cross-validation and 86.74% for Jack-Knife validation. Two more algorithms, RBF network and support vector machine (SVM, also have been employed and compared with NBA-Palm. Conclusion Taken together, our analyses demonstrate that NBA-Palm is a useful computational program that provides insights for further experimentation. The accuracy of NBA-Palm is comparable with our previously described tool CSS-Palm. The NBA-Palm is freely accessible from: http://www.bioinfo.tsinghua.edu.cn/NBA-Palm.

  18. NBA-Palm: prediction of palmitoylation site implemented in Naïve Bayes algorithm.

    Science.gov (United States)

    Xue, Yu; Chen, Hu; Jin, Changjiang; Sun, Zhirong; Yao, Xuebiao

    2006-10-17

    Protein palmitoylation, an essential and reversible post-translational modification (PTM), has been implicated in cellular dynamics and plasticity. Although numerous experimental studies have been performed to explore the molecular mechanisms underlying palmitoylation processes, the intrinsic feature of substrate specificity has remained elusive. Thus, computational approaches for palmitoylation prediction are much desirable for further experimental design. In this work, we present NBA-Palm, a novel computational method based on Naïve Bayes algorithm for prediction of palmitoylation site. The training data is curated from scientific literature (PubMed) and includes 245 palmitoylated sites from 105 distinct proteins after redundancy elimination. The proper window length for a potential palmitoylated peptide is optimized as six. To evaluate the prediction performance of NBA-Palm, 3-fold cross-validation, 8-fold cross-validation and Jack-Knife validation have been carried out. Prediction accuracies reach 85.79% for 3-fold cross-validation, 86.72% for 8-fold cross-validation and 86.74% for Jack-Knife validation. Two more algorithms, RBF network and support vector machine (SVM), also have been employed and compared with NBA-Palm. Taken together, our analyses demonstrate that NBA-Palm is a useful computational program that provides insights for further experimentation. The accuracy of NBA-Palm is comparable with our previously described tool CSS-Palm. The NBA-Palm is freely accessible from: http://www.bioinfo.tsinghua.edu.cn/NBA-Palm.

  19. Lytic polysaccharide monooxygenases from Myceliophthora thermophila C1

    NARCIS (Netherlands)

    Frommhagen, Matthias

    2017-01-01

    Current developments aim at the effective enzymatic degradation of plant biomass polysaccharides into fermentable monosaccharides for biofuels and biochemicals. Recently discovered lytic polysaccharide monooxgygenases (LPMOs) boost the hydrolytic breakdown of lignocellulosic biomass, especially

  20. Effect of metals on the lytic cycle of the coccolithovirus, EhV86.

    Directory of Open Access Journals (Sweden)

    Martha eGledhill

    2012-04-01

    Full Text Available In this study we show that metals, and in particular copper (Cu, can disrupt the lytic cycle in the Emiliania huxleyi - EhV86 host-virus system. Numbers of virus particles produced per E. huxleyi cell and E. huxleyi lysis rates were reduced by Cu at total metal concentrations over 500 nM in the presence of EDTA (ethylenediaminetetraacetic acid, and 250 nM in the absence of EDTA in acute short term exposure experiments. Zinc (Zn, cadmium (Cd and cobalt (Co were not observed to affect the lysis rate of EhV86 in these experiments. The cellular glutathione (GSH content increased in virus infected cells, but not as a result of metal exposure. In contrast, the cellular content of phytochelatins (PCs increased only in response to metal exposure. The increase in gluthatione content is consistent with increases in the production of reactive oxygen species (ROS on viral infection, while increases in PC content are likely linked to metal homeostasis and indicate that metal toxicity to the host was not affected by viral infection. We propose that Cu prevents lytic production of EhV86 by interfering with virus DNA (deoxyribonucleic acid synthesis through a transcriptional block, which ultimately suppresses the formation of ROS, a biochemical response required for successful virus infection.

  1. A palmitoylation switch mechanism regulates Rac1 function and membrane organization

    Science.gov (United States)

    Navarro-Lérida, Inmaculada; Sánchez-Perales, Sara; Calvo, María; Rentero, Carles; Zheng, Yi; Enrich, Carlos; Del Pozo, Miguel A

    2012-01-01

    The small GTPase Rac1 plays important roles in many processes, including cytoskeletal reorganization, cell migration, cell-cycle progression and gene expression. The initiation of Rac1 signalling requires at least two mechanisms: GTP loading via the guanosine triphosphate (GTP)/guanosine diphosphate (GDP) cycle, and targeting to cholesterol-rich liquid-ordered plasma membrane microdomains. Little is known about the molecular mechanisms governing this specific compartmentalization. We show that Rac1 can incorporate palmitate at cysteine 178 and that this post-translational modification targets Rac1 for stabilization at actin cytoskeleton-linked ordered membrane regions. Palmitoylation of Rac1 requires its prior prenylation and the intact C-terminal polybasic region and is regulated by the triproline-rich motif. Non-palmitoylated Rac1 shows decreased GTP loading and lower association with detergent-resistant (liquid-ordered) membranes (DRMs). Cells expressing no Rac1 or a palmitoylation-deficient mutant have an increased content of disordered membrane domains, and markers of ordered membranes isolated from Rac1-deficient cells do not correctly partition in DRMs. Importantly, cells lacking Rac1 palmitoylation show spreading and migration defects. These data identify palmitoylation as a mechanism for Rac1 function in actin cytoskeleton remodelling by controlling its membrane partitioning, which in turn regulates membrane organization. PMID:22157745

  2. The Palmitoylation State of PMP22 Modulates Epithelial Cell Morphology and Migration

    Directory of Open Access Journals (Sweden)

    Susie J. Zoltewicz

    2012-11-01

    Full Text Available PMP22 (peripheral myelin protein 22, also known as GAS 3 (growth-arrest-specific protein 3, is a disease-linked tetraspan glycoprotein of peripheral nerve myelin and constituent of intercellular junctions in epithelia. To date, our knowledge of the post-translational modification of PMP22 is limited. Using the CSS-Palm 2.0 software we predicted that C85 (cysteine 85, a highly conserved amino acid located between the second and third transmembrane domains, is a potential site for palmitoylation. To test this, we mutated C85S (C85 to serine and established stable cells lines expressing the WT (wild-type or the C85S-PMP22. In Schwann and MDCK (Madin–Darby canine kidney cells mutating C85 blocked the palmitoylation of PMP22, which we monitored using 17-ODYA (17-octadecynoic acid. While palmitoylation was not necessary for processing the newly synthesized PMP22 through the secretory pathway, overexpression of C85S-PMP22 led to pronounced cell spreading and uneven monolayer thinning. To further investigate the functional significance of palmitoylated PMP22, we evaluated MDCK cell migration in a wound-healing assay. While WT-PMP22 expressing cells were resistant to migration, C85S cells displayed lamellipodial protrusions and migrated at a similar rate to vector control. These findings indicate that palmitoylation of PMP22 at C85 is critical for the role of the protein in modulating epithelial cell shape and motility.

  3. Are Phage Lytic Proteins the Secret Weapon To Kill Staphylococcus aureus?

    Science.gov (United States)

    Gutiérrez, Diana; Fernández, Lucía; Rodríguez, Ana; García, Pilar

    2018-01-23

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening microorganisms for global human health. The current strategies to reduce the impact of S. aureus include a restrictive control of worldwide antibiotic use, prophylactic measures to hinder contamination, and the search for novel antimicrobials to treat human and animal infections caused by this bacterium. The last strategy is currently the focus of considerable research. In this regard, phage lytic proteins (endolysins and virion-associated peptidoglycan hydrolases [VAPGHs]) have been proposed as suitable candidates. Indeed, these proteins display narrow-spectrum antimicrobial activity and a virtual lack of bacterial-resistance development. Additionally, the therapeutic use of phage lytic proteins in S. aureus animal infection models is yielding promising results, showing good efficacy without apparent side effects. Nonetheless, human clinical trials are still in progress, and data are not available yet. This minireview also analyzes the main obstacles for introducing phage lytic proteins as human therapeutics against S. aureus infections. Besides the common technological problems derived from large-scale production of therapeutic proteins, a major setback is the lack of a proper legal framework regulating their use. In that sense, the relevant health authorities should urgently have a timely discussion about these new antimicrobials. On the other hand, the research community should provide data to dispel any doubts regarding their efficacy and safety. Overall, the appropriate scientific data and regulatory framework will encourage pharmaceutical companies to invest in these promising antimicrobials. Copyright © 2018 Gutiérrez et al.

  4. Identification of conserved regions and residues within Hedgehog acyltransferase critical for palmitoylation of Sonic Hedgehog.

    Directory of Open Access Journals (Sweden)

    John A Buglino

    2010-06-01

    Full Text Available Sonic hedgehog (Shh is a palmitoylated protein that plays key roles in mammalian development and human cancers. Palmitoylation of Shh is required for effective long and short range Shh-mediated signaling. Attachment of palmitate to Shh is catalyzed by Hedgehog acyltransferase (Hhat, a member of the membrane bound O-acyl transferase (MBOAT family of multipass membrane proteins. The extremely hydrophobic composition of MBOAT proteins has limited their biochemical characterization. Except for mutagenesis of two conserved residues, there has been no structure-function analysis of Hhat, and the regions of the protein required for Shh palmitoylation are unknown.Here we undertake a systematic approach to identify residues within Hhat that are required for protein stability and/or enzymatic activity. We also identify a second, novel MBOAT homology region (residues 196-234 that is required for Hhat activity. In total, ten deletion mutants and eleven point mutants were generated and analyzed. Truncations at the N- and C-termini of Hhat yielded inactive proteins with reduced stability. Four Hhat mutants with deletions within predicted loop regions and five point mutants retained stability but lost palmitoylation activity. We purified two point mutants, W378A and H379A, with defective Hhat activity. Kinetic analyses revealed alterations in apparent K(m and V(max for Shh and/or palmitoyl CoA, changes that likely explain the catalytic defects observed for these mutants.This study has pinpointed specific regions and multiple residues that regulate Hhat stability and catalysis. Our findings should be applicable to other MBOAT proteins that mediate lipid modification of Wnt proteins and ghrelin, and should serve as a model for understanding how secreted morphogens are modified by palmitoyl acyltransferases.

  5. Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii*

    OpenAIRE

    Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

    2015-01-01

    Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure ...

  6. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many...... or an amide bond. It was found that these S-palmitoylated peptides were much more immunogenic than N-palmitoylated peptides and at least similar to KLH-conjugated peptides with respect to appearance and magnitude of induced antibodies (canine parvovirus) or immunocastration effect (gonadotropin...

  7. Synthesis of N-Acylated Amino Acid Surfactant from L-Proline and Palmitoyl Chloride

    International Nuclear Information System (INIS)

    Meutia Fadhilah Hasibuan; Mohd Wahid Samsudin; Rahimi Mohd Yusop; Suria Ramli

    2015-01-01

    A biodegradable, less toxic and environmentally friendly N-acylated amino acid surfactant was prepared from the amino acid L-proline and palmitoyl chloride through acylation reaction using the Schotten-Baumann reaction condition. The reaction result was a white flake form and the percentage of the crude yield was 72 % with melting point in range of 52 - 58 degree Celsius. Functional group of amide which was detected using Fourier Transform Infrared method showed the presence of N-palmitoyl proline. The purity analysis using High Performance Liquid Chromatography and Thin Layer Chromatography showed the result was a mixture compound. (author)

  8. Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Daniela F Angelini

    Full Text Available It has long been known that multiple sclerosis (MS is associated with an increased Epstein-Barr virus (EBV seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A and lytic (BZLF-1, BMLF-1 antigens in relapsing-remitting MS patients (n = 113 and healthy donors (HD (n = 43 and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging. Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS. Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

  9. Metastatic Breast Cancer or Multiple Myeloma? Camouflage by Lytic Lesions

    Directory of Open Access Journals (Sweden)

    Bruce Hough

    2010-01-01

    Full Text Available We report a case of a female with stage I infiltrating ductal carcinoma who received adjuvant therapy including trastuzumab. One year later she developed lytic lesions and was retreated with trastuzumab that was held after she developed symptomatic heart failure. Lytic lesions were attributed to relapse of breast cancer, and cardiac failure attributed to prior trastuzumab therapy. After complications necessitated multiple hospitalizations, a further workup revealed that the lytic lesions were not metastatic breast cancer but multiple myeloma. Her advanced multiple myeloma was associated with systemic amyloidosis involving gut and heart, which ultimately led to her demise. This report addresses the pitfalls of overlapping symptoms and the question of which patients with suspected metastatic disease should undergo a biopsy.

  10. A Temporal Proteomic Map of Epstein-Barr Virus Lytic Replication in B Cells

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    Ina Ersing

    2017-05-01

    Full Text Available Epstein-Barr virus (EBV replication contributes to multiple human diseases, including infectious mononucleosis, nasopharyngeal carcinoma, B cell lymphomas, and oral hairy leukoplakia. We performed systematic quantitative analyses of temporal changes in host and EBV proteins during lytic replication to gain insights into virus-host interactions, using conditional Burkitt lymphoma models of type I and II EBV infection. We quantified profiles of >8,000 cellular and 69 EBV proteins, including >500 plasma membrane proteins, providing temporal views of the lytic B cell proteome and EBV virome. Our approach revealed EBV-induced remodeling of cell cycle, innate and adaptive immune pathways, including upregulation of the complement cascade and proteasomal degradation of the B cell receptor complex, conserved between EBV types I and II. Cross-comparison with proteomic analyses of human cytomegalovirus infection and of a Kaposi-sarcoma-associated herpesvirus immunoevasin identified host factors targeted by multiple herpesviruses. Our results provide an important resource for studies of EBV replication.

  11. Characterization and lytic activity of methicillin-resistant Staphylococcus aureus(MRSA phages isolated from NICU

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    Golnar Rahimzadeh

    2016-06-01

    Full Text Available Background Methicillin-resistant Staphylococcus aureus (MRSA is a well-known pathogen that causes serious diseases in humans. As part of the efforts to control this pathogen, an isolated bacteriophage, Siphoviridae, which specifically targets Methicillin-resistant Staphylococcus aureus (MRSA, was characterized. Aims The objective of this study was to characterize of a virulent bacteriophage (Siphoviridae isolated from a NICU bathroom sink. Methods The MRSA strain was isolated from patient blood. The isolated strain was confirmed as MRSA using conventional methods. Phages were isolated from a NICU bathroom sink and activity was lytic as determined by spot test. Titer phage lysate was measured by the Double Layer Agar (DLA technique. The morphology was found with electron microscopy. The single-step growth curve was plotted. Results Electron microscopy showed the phage as a member of the family Siphoviridae, serogroup A and F. The isolated phage was capable of lytic activity against methicillin-resistant Staphylococcus aureus (MRSA strain as shown by spot test. By DLA, the titre of the phages was determined to be 10×108PFU/ml. The single-step growth curve showed that the latent period of the isolated bacteriophage was 30 min and the total number of viable progeny per infected host, burst size, was 2600 PFU/infected host. Conclusion In this study, two phages were isolated and characterized from a NICU bathroom sink, from the Siphoviridae family, which specifically targetsmethicillin-resistant Staphylococcus aureus (MRSA.

  12. Interactions between Melanin Enzymes and Their Atypical Recruitment to the Secretory Pathway by Palmitoylation

    Directory of Open Access Journals (Sweden)

    Srijana Upadhyay

    2016-11-01

    Full Text Available Melanins are biopolymers that confer coloration and protection to the host organism against biotic or abiotic insults. The level of protection offered by melanin depends on its biosynthesis and its subcellular localization. Previously, we discovered that Aspergillus fumigatus compartmentalizes melanization in endosomes by recruiting all melanin enzymes to the secretory pathway. Surprisingly, although two laccases involved in the late steps of melanization are conventional secretory proteins, the four enzymes involved in the early steps of melanization lack a signal peptide or a transmembrane domain and are thus considered “atypical” secretory proteins. In this work, we found interactions among melanin enzymes and all melanin enzymes formed protein complexes. Surprisingly, the formation of protein complexes by melanin enzymes was not critical for their trafficking to the endosomal system. By palmitoylation profiling and biochemical analyses, we discovered that all four early melanin enzymes were strongly palmitoylated during conidiation. However, only the polyketide synthase (PKS Alb1 was strongly palmitoylated during both vegetative hyphal growth and conidiation when constitutively expressed alone. This posttranslational lipid modification correlates the endosomal localization of all early melanin enzymes. Intriguingly, bioinformatic analyses predict that palmitoylation is a common mechanism for potential membrane association of polyketide synthases (PKSs and nonribosomal peptide synthetases (NRPSs in A. fumigatus. Our findings indicate that protein-protein interactions facilitate melanization by metabolic channeling, while posttranslational lipid modifications help recruit the atypical enzymes to the secretory pathway, which is critical for compartmentalization of secondary metabolism.

  13. Palmitoylation regulates 17β-estradiol-induced estrogen receptor-α degradation and transcriptional activity.

    Science.gov (United States)

    La Rosa, Piergiorgio; Pesiri, Valeria; Leclercq, Guy; Marino, Maria; Acconcia, Filippo

    2012-05-01

    The estrogen receptor-α (ERα) is a transcription factor that regulates gene expression through the binding to its cognate hormone 17β-estradiol (E2). ERα transcriptional activity is regulated by E2-evoked 26S proteasome-mediated ERα degradation and ERα serine (S) residue 118 phosphorylation. Furthermore, ERα mediates fast cell responses to E2 through the activation of signaling cascades such as the MAPK/ERK and phosphoinositide-3-kinase/v-akt murine thymoma viral oncogene homolog 1 pathways. These E2 rapid effects require a population of the ERα located at the cell plasma membrane through palmitoylation, a dynamic enzymatic modification mediated by palmitoyl-acyl-transferases. However, whether membrane-initiated and transcriptional ERα activities integrate in a unique picture or represent parallel pathways still remains to be firmly clarified. Hence, we evaluated here the impact of ERα palmitoylation on E2-induced ERα degradation and S118 phosphorylation. The lack of palmitoylation renders ERα more susceptible to E2-dependent degradation, blocks ERα S118 phosphorylation and prevents E2-induced ERα estrogen-responsive element-containing promoter occupancy. Consequently, ERα transcriptional activity is prevented and the receptor addressed to the nuclear matrix subnuclear compartment. These data uncover a circuitry in which receptor palmitoylation links E2-dependent ERα degradation, S118 phosphorylation, and transcriptional activity in a unique molecular mechanism. We propose that rapid E2-dependent signaling could be considered as a prerequisite for ERα transcriptional activity and suggest an integrated model of ERα intracellular signaling where E2-dependent early extranuclear effects control late receptor-dependent nuclear actions.

  14. MUREIN-METABOLIZING ENZYMES FROM ESCHERICHIA-COLI - EXISTENCE OF A 2ND LYTIC TRANSGLYCOSYLASE

    NARCIS (Netherlands)

    ENGEL, H; SMINK, AJ; VANWIJNGAARDEN, L; KECK, W

    1992-01-01

    In addition to the soluble lytic transglycosylase, a murein-metabolizing enzyme with a molecular mass of 70 kDa (Slt70), Escherichia coli possesses a second lytic transglycosylase, which has been described as a membrane-bound lytic transglycosylase (Mlt; 35 kDa; EC 3.2.1.-). The mlt gene, which

  15. Efficient Translation of Epstein-Barr Virus (EBV) DNA Polymerase Contributes to the Enhanced Lytic Replication Phenotype of M81 EBV.

    Science.gov (United States)

    Church, Trenton Mel; Verma, Dinesh; Thompson, Jacob; Swaminathan, Sankar

    2018-03-15

    Epstein-Barr virus (EBV) is linked to the development of both lymphoid and epithelial malignancies worldwide. The M81 strain of EBV, isolated from a Chinese patient with nasopharyngeal carcinoma (NPC), demonstrates spontaneous lytic replication and high-titer virus production in comparison to the prototype B95-8 EBV strain. Genetic comparisons of M81 and B95-8 EBVs were previously been performed in order to determine if the hyperlytic property of M81 is associated with sequence differences in essential lytic genes. EBV SM is an RNA-binding protein expressed during early lytic replication that is essential for virus production. We compared the functions of M81 SM and B95-8 SM and demonstrate that polymorphisms in SM do not contribute to the lytic phenotype of M81 EBV. However, the expression level of the EBV DNA polymerase protein was much higher in M81- than in B95-8-infected cells. The relative deficiency in the expression of B95-8 DNA polymerase was related to the B95-8 genome deletion, which truncates the BALF5 3' untranslated region (UTR). Similarly, the insertion of bacmid DNA into the widely used recombinant B95-8 bacmid creates an inefficient BALF5 3' UTR. We further showed that the while SM is required for and facilitates the efficient expression of both M81 and B95-8 mRNAs regardless of the 3' UTR, the BALF5 3' UTR sequence is important for BALF5 protein translation. These data indicate that the enhanced lytic replication and virus production of M81 compared to those of B95-8 are partly due to the robust translation of EBV DNA polymerase required for viral DNA replication due to a more efficient BALF5 3' UTR in M81. IMPORTANCE Epstein-Barr virus (EBV) infects more than 90% of the human population, but the incidence of EBV-associated tumors varies greatly in different parts of the world. Thus, understanding the connection between genetic polymorphisms from patient isolates of EBV, gene expression phenotypes, and disease is important and may help in

  16. PARTIAL CHARACTERIZATION OF A LYTIC METHICILLIN RESISTANT-STAPHYLOCOCCUS AUREUS BACTERIOPHAGE

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    Sulaiman Al-Yousef

    2014-12-01

    Full Text Available A marked increase in the infection incidence caused by methicillin-resistant Staphylococcus aureus (MRSA strains has been noted in medical practice in recent years. This study was conducted to study the biological and characterize of MRSA-phage. Methicillin resistance of Staphylococcus aureus was detected and confirmed by determining of the MIC of oxacillin by the standard agar dilution method. Phage was biologically purified using single plaque technique, then phage characterization were studied using host range, adsorption time, particle morphology and its structural protein. MRSA phage showing lytic nature was purified by repeated plating after picking of single isolated plaques. This phage is active against all 11 isolates either of S. aureus or MRSA tested as hosts. Phage produced clear plaques indicating their lytic nature. This phage was concentrated employing polyethylene glycol (PEG-NaCl precipitation method. Morphologically, MRSA Phage has a hexagonal head having a long non-contractile tail, indicating his icosahedral nature. Adsorption studies showed 100% adsorption of MRSA-Phage after 35 minutes of exposure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE experimentation indicated that the phage particles contain one major structural protein (about 30 Kda.

  17. Differential impact of lytic viruses on prokaryotic morphopopulations in a tropical estuarine system (Cochin estuary, India).

    Science.gov (United States)

    Jasna, Vijayan; Pradeep Ram, Angia Sriram; Parvathi, Ammini; Sime-Ngando, Telesphore

    2018-01-01

    Our understanding on the importance of viral lysis in the functioning of tropical estuarine ecosystem is limited. This study examines viral infection of prokaryotes and subsequent lysis of cells belonging to different morphotypes across a salinity gradient in monsoon driven estuarine ecosystem (Cochin estuary, India). High standing stock of viruses and prokaryotes accompanied by lytic infection rates in the euryhaline/mesohaline region of the estuary suggests salinity to have an influential role in driving interactions between prokaryotes and viruses. High prokaryotic mortality rates, up to 42% of prokaryote population in the pre-monsoon season is further substantiated by a high virus to prokaryote ratio (VPR), suggesting that maintenance of a high number of viruses is dependent on the most active fraction of bacterioplankton. Although myoviruses were the dominant viral morphotype (mean = 43%) throughout the study period, there was significant variation among prokaryotic morphotypes susceptible to viral infection. Among them, the viral infected short rod prokaryote morphotype with lower burst estimates (mean = 18 viruses prokaryote-1) was dominant (35%) in the dry seasons whereas a substantial increase in cocci forms (30%) infected by viruses with high burst size (mean = 31 viruses prokaryote-1) was evident during the monsoon season. Such preferential infections of prokaryotic morphopopulations with respect to seasons can have a strong and variable impact on the carbon and energy flow in this tropical ecosystem.

  18. Delta-9 tetrahydrocannabinol (THC inhibits lytic replication of gamma oncogenic herpesviruses in vitro

    Directory of Open Access Journals (Sweden)

    Friedman Herman

    2004-09-01

    Full Text Available Abstract Background The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC, has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication. Methods Tissue cultures infected with various gamma herpesviruses were cultured in the presence of increasing concentrations of THC and the amount of viral DNA or infectious virus yield was compared to those of control cultures. The effect of THC on Kaposi's Sarcoma Associated Herpesvirus (KSHV and Epstein-Barr virus (EBV replication was measured by the Gardella method and replication of herpesvirus saimiri (HVS of monkeys, murine gamma herpesvirus 68 (MHV 68, and herpes simplex type 1 (HSV-1 was measured by yield reduction assays. Inhibition of the immediate early ORF 50 gene promoter activity was measured by the dual luciferase method. Results Micromolar concentrations of THC inhibit KSHV and EBV reactivation in virus infected/immortalized B cells. THC also strongly inhibits lytic replication of MHV 68 and HVS in vitro. Importantly, concentrations of THC that inhibit virus replication of gamma herpesviruses have no effect on cell growth or HSV-1 replication, indicating selectivity. THC was shown to selectively inhibit the immediate early ORF 50 gene promoter of KSHV and MHV 68. Conclusions THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC

  19. Delta-9 tetrahydrocannabinol (THC) inhibits lytic replication of gamma oncogenic herpesviruses in vitro.

    Science.gov (United States)

    Medveczky, Maria M; Sherwood, Tracy A; Klein, Thomas W; Friedman, Herman; Medveczky, Peter G

    2004-09-15

    The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC), has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication. Tissue cultures infected with various gamma herpesviruses were cultured in the presence of increasing concentrations of THC and the amount of viral DNA or infectious virus yield was compared to those of control cultures. The effect of THC on Kaposi's Sarcoma Associated Herpesvirus (KSHV) and Epstein-Barr virus (EBV) replication was measured by the Gardella method and replication of herpesvirus saimiri (HVS) of monkeys, murine gamma herpesvirus 68 (MHV 68), and herpes simplex type 1 (HSV-1) was measured by yield reduction assays. Inhibition of the immediate early ORF 50 gene promoter activity was measured by the dual luciferase method. Micromolar concentrations of THC inhibit KSHV and EBV reactivation in virus infected/immortalized B cells. THC also strongly inhibits lytic replication of MHV 68 and HVS in vitro. Importantly, concentrations of THC that inhibit virus replication of gamma herpesviruses have no effect on cell growth or HSV-1 replication, indicating selectivity. THC was shown to selectively inhibit the immediate early ORF 50 gene promoter of KSHV and MHV 68. THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC. These studies may also provide the foundation for the development

  20. Polarized trafficking: the palmitoylation cycle distributes cytoplasmic proteins to distinct neuronal compartments.

    Science.gov (United States)

    Tortosa, Elena; Hoogenraad, Casper C

    2018-02-01

    In neurons, polarized cargo distribution occurs mainly between the soma and axonal and dendritic compartments, and requires coordinated regulation of cytoskeletal remodeling and membrane trafficking. The Golgi complex plays a critical role during neuronal polarization and secretory trafficking has been shown to differentially transport proteins to both axons and dendrites. Besides the Golgi protein sorting, recent data revealed that palmitoylation cycles are an efficient mechanism to localize cytoplasmic, non-transmembrane proteins to particular neuronal compartments, such as the newly formed axon. Palmitoylation allows substrate proteins to bind to and ride with Golgi-derived secretory vesicles to all neuronal compartments. By allowing cytoplasmic proteins to 'hitchhike' on transport carriers in a non-polarized fashion, compartmentalized depalmitoylation may act as a selective retention mechanism. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Su, Xiong [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Liu, Jialiu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Sundaresan, Sinju [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Stahl, Philip D., E-mail: pstahl@wustl.edu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)

    2013-05-03

    Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

  2. Imidazopyridine and Pyrazolopiperidine Derivatives as Novel Inhibitors of Serine Palmitoyl Transferase.

    Science.gov (United States)

    Genin, Michael J; Gonzalez Valcarcel, Isabel C; Holloway, William G; Lamar, Jason; Mosior, Marian; Hawkins, Eric; Estridge, Thomas; Weidner, Jeffrey; Seng, Thomas; Yurek, David; Adams, Lisa A; Weller, Jennifer; Reynolds, Vincent L; Brozinick, Joseph T

    2016-06-23

    To develop novel treatments for type 2 diabetes and dyslipidemia, we pursued inhibitors of serine palmitoyl transferase (SPT). To this end compounds 1 and 2 were developed as potent SPT inhibitors in vitro. 1 and 2 reduce plasma ceramides in rodents, have a slight trend toward enhanced insulin sensitization in DIO mice, and reduce triglycerides and raise HDL in cholesterol/cholic acid fed rats. Unfortunately these molecules cause a gastric enteropathy after chronic dosing in rats.

  3. Posttranslational protein S-palmitoylation and the compartmentalization of signaling molecules in neurons

    Directory of Open Access Journals (Sweden)

    SEAN I PATTERSON

    2002-01-01

    Full Text Available Protein domains play a fundamental role in the spatial and temporal organization of intracellular signaling systems. While protein phosphorylation has long been known to modify the interactions that underlie this organization, the dynamic cycling of lipids should now be included amongst the posttranslational processes determining specificity in signal transduction. The characteristics of this process are reminiscent of the properties of protein and lipid phosphorylation in determining compartmentalization through SH2 or PH domains. Recent studies have confirmed the functional importance of protein S-palmitoylation in the compartmentalization of signaling molecules that support normal physiological function in cell division and apoptosis, and synaptic transmission and neurite outgrowth. In neurons, S-palmitoylation and targeting of proteins to rafts are regulated differentially in development by a number of processes, including some related to synaptogenesis and synaptic plasticity. Alterations in the S-palmitoylation state of proteins substantially affect their cellular function, raising the possibility of new therapeutic targets in cancer and nervous system injury and disease.

  4. Effective inhibition of lytic development of bacteriophages λ, P1 and T4 by starvation of their host, Escherichia coli

    Directory of Open Access Journals (Sweden)

    Węgrzyn Alicja

    2007-02-01

    Full Text Available Abstract Background Bacteriophage infections of bacterial cultures cause serious problems in genetic engineering and biotechnology. They are dangerous not only because of direct effects on the currently infected cultures, i.e. their devastation, but also due to a high probability of spreading the phage progeny throughout a whole laboratory or plant, which causes a real danger for further cultivations. Therefore, a simple method for quick inhibition of phage development after detection of bacterial culture infection should be very useful. Results Here, we demonstrate that depletion of a carbon source from the culture medium, which provokes starvation of bacterial cells, results in rapid inhibition of lytic development of three Escherichia coli phages, λ, P1 and T4. Since the effect was similar for three different phages, it seems that it may be a general phenomenon. Moreover, similar effects were observed in flask cultures and in chemostats. Conclusion Bacteriophage lytic development can be inhibited efficiently by carbon source limitation in bacterial cultures. Thus, if bacteriophage contamination is detected, starvation procedures may be recommended to alleviate deleterious effects of phage infection on the culture. We believe that this strategy, in combination with the use of automated and sensitive bacteriophage biosensors, may be employed in the fermentation laboratory practice to control phage outbreaks in bioprocesses more effectively.

  5. Chaetocin reactivates the lytic replication of Epstein-Barr virus from latency via reactive oxygen species.

    Science.gov (United States)

    Zhang, Shilun; Yin, Juan; Zhong, Jiang

    2017-01-01

    Oxidative stress, regarded as a negative effect of free radicals in vivo, takes place when organisms suffer from harmful stimuli. Some viruses can induce the release of reactive oxygen species (ROS) in infected cells, which may be closely related with their pathogenicity. In this report, chaetocin, a fungal metabolite reported to have antimicrobial and cytostatic activity, was studied for its effect on the activation of latent Epstein-Barr virus (EBV) in B95-8 cells. We found that chaetocin remarkably up-regulated EBV lytic transcription and DNA replication at a low concentration (50 nmol L -1 ). The activation of latent EBV was accompanied by an increased cellular ROS level. N-acetyl-L-cysteine (NAC), an ROS inhibitor, suppressed chaetocin-induced EBV activation. Chaetocin had little effect on histone H3K9 methylation, while NAC also significantly reduced H3K9 methylation. These results suggested that chaetocin reactivates latent EBV primarily via ROS pathways.

  6. Utility of lytic bacteriophage in the treatment of multidrug-resistant Pseudomonas aeruginosa septicemia in mice

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    Vinodkumar C

    2008-07-01

    Full Text Available Drug resistance is the major cause of increase in morbidity and mortality in neonates. One thousand six hundred forty-seven suspected septicemic neonates were subjected for microbiological analysis over a period of 5 years. Forty-two P. aeruginosa were isolated and the antibiogram revealed that 28 P. aeruginosa were resistant to almost all the common drugs used (multidrug-resistant. The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. As a result, a novel and most effective approaches for treating infection caused by multidrug-resistant bacteria are urgently required. In this context, one intriguing approach is to use bacteriophages (viruses that kill bacteria in the treatment of infection caused by drug-resistant bacteria. In the present study, the utility of lytic bacteriophages to rescue septicemic mice with multidrug-resistant (MDR P. aeruginosa infection was evaluated. MDR P. aeruginosa was used to induce septicemia in mice by intraperitoneal (i.p. injection of 10 7 CFU. The resulting bacteremia was fatal within 48 hrs. The phage strain used in this study had lytic activity against a wide range of clinical isolates of MDR P. aeruginosa. A single i.p. injection of 3 x 10 9 PFU of the phage strain, administered 45 min after the bacterial challenge, was sufficient to rescue 100% of the animals. Even when treatment was delayed to the point where all animals were moribund, approximately 50% of them were rescued by a single injection of this phage preparation. The ability of this phage to rescue septicemic mice was demonstrated to be due to the functional capabilities of the phage and not to a nonspecific immune effect. The rescue of septicemic mice could be affected only by phage strains able to grow in vitro on the bacterial host used to infect the animals and when such strains are heat-inactivated, they lose their ability to rescue the infected mice. Multidrug-resistant bacteria have

  7. Role of protein kinase C in TBT-induced inhibition of lytic function and MAPK activation in human natural killer cells.

    Science.gov (United States)

    Abraha, Abraham B; Rana, Krupa; Whalen, Margaret M

    2010-11-01

    Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposure of NK cells to tributyltin (TBT) greatly diminishes their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C(PKC) as well as MAPK activity. TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to a subsequent encounter with a target cell. In the present study we evaluated the involvement of PKC in inhibition of NK lysis of tumor cells and activation of MAPKs caused by TBT exposure. TBT caused a 2–3-fold activation of PKC at concentrations ranging from 50 to 300 nM (16–98 ng/ml),indicating that activation of PKC occurs in response to TBT exposure. This would then leave the NK cell unable to respond to targets. Treatment with the PKC inhibitor, bisindolylmaleimide I, caused an 85% decrease in the ability of NK cells to lyse tumor cells, validating the involvement of PKC in the lytic signaling pathway. The role of PKC in the activation of MAPKs by TBT was also investigated using bisindolylmaleimide I. The results indicated that, in NK cells where PKC activation was blocked, there was no activation of the MAPK, p44/42 in response to TBT.However, TBT-induced activation of the MAPKs, p38 and JNK did not require PKC activation. These results indicate the pivotal role of PKC in the TBT-induced loss of NK lytic function including activation of p44/42 by TBT in NK cells.

  8. Role of protein kinase C in the TBT-induced inhibition of lytic function and MAPK activation in human natural killer cells

    Science.gov (United States)

    Abraha, Abraham B.; Rana, Krupa; Whalen, Margaret M.

    2010-01-01

    Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposures of NK cells to tributyltin (TBT) greatly diminish their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in the NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C (PKC) as well as MAPK activity. The TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to a subsequent encounter with a target cell. In the present study we evaluated the involvement of PKC in the inhibition of NK lysis of tumor cells and activation of MAPKs caused by TBT exposures. TBT caused a 2–3 fold activation of PKC at concentrations ranging from 50–300 nM (16–98 ng/mL), indicating that activation of PKC occurs in response to TBT exposures. This would then leave the NK cell unable to respond to targets. Treatment with the PKC inhibitor, bisindolylmaleimide I, caused an 85% decrease in the ability of NK cells to lyse tumor cells validating the involvement of PKC in the lytic signaling pathway. The role of PKC in the activation of MAPKs by TBT was also investigated using bisindolylmaleimide I. The results indicated that in NK cells where PKC activation was blocked there was no activation of the MAPK, p44/42 in response to TBT. However, TBT-induced activation of the MAPKs, p38 and JNK did not require PKC activation. These results indicate the pivotal role of PKC in the TBT-induced loss of NK lytic function including the activation of p44/42 by TBT in NK cells. PMID:20390410

  9. CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function.

    Science.gov (United States)

    Jain, Nidhi; Oswal, Neelam; Chawla, Amanpreet Singh; Agrawal, Tanvi; Biswas, Moanaro; Vrati, Sudhanshu; Rath, Satyajit; George, Anna; Bal, Vineeta; Medigeshi, Guruprasad R

    2017-02-01

    Following Japanese encephalitis virus (JEV) infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β-T cells (TCRβ-null) are highly susceptible and die over 10-18 day period as compared to the wild-type (WT) mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB). Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage.

  10. CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function.

    Directory of Open Access Journals (Sweden)

    Nidhi Jain

    2017-02-01

    Full Text Available Following Japanese encephalitis virus (JEV infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β-T cells (TCRβ-null are highly susceptible and die over 10-18 day period as compared to the wild-type (WT mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB. Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage.

  11. The importance of claudin-7 palmitoylation on membrane subdomain localization and metastasis-promoting activities

    OpenAIRE

    Heiler, Sarah; Mu, Wei; Z?ller, Margot; Thuma, Florian

    2015-01-01

    Background Claudin-7 (cld7), a tight junction (TJ) component, is also found basolaterally and in the cytoplasm. Basolaterally located cld7 is enriched in glycolipid-enriched membrane domains (GEM), where it associates with EpCAM (EpC). The conditions driving cld7 out of TJ into GEM, which is associated with a striking change in function, were not defined. Thus, we asked whether cld7 serines or palmitoylation affect cld7 location and protein, particularly EpCAM, associations. Results HEK cells...

  12. Percutaneous aspiration biopsy in cervical spine lytic lesions

    International Nuclear Information System (INIS)

    Tampieri, D.; Weill, A.; Melanson, D.; Ethier, R.

    1991-01-01

    We describe the technique and the results of the percutaneous aspiration biopsy (PAB) in a series of 9 patients presenting with neck pain and different degrees of myelopathy, in whom the cervical spine X-ray demonstrated lytic lesions of unknown origin. PAB is a useful, relatively safe technique, and leads to histological diagnosis between metastatic and inflammatory processes. Furthermore, in inflammatory lesions with negative hemoculture, PAB may help in detecting the micro-organism responsible and therefore allow a better antibiotic treatment. (orig.)

  13. Abortive lytic Epstein–Barr virus replication in tonsil-B lymphocytes in infectious mononucleosis and a subset of the chronic fatigue syndrome

    Directory of Open Access Journals (Sweden)

    Lerner AM

    2012-11-01

    Full Text Available A Martin Lerner,1 Safedin Beqaj21Department of Medicine, Oakland University William Beaumont School of Medicine, Rochester, MI, USA; 2Pathology Inc, Torrance, CA, USAAbstract: A systematic 2001–2007 review of 142 chronic fatigue syndrome (CFS patients identified 106 CFS patients with elevated serum IgG antibodies to the herpesviruses Epstein–Barr virus (EBV, cytomegalovirus, or human herpesvirus (HHV 6 in single or multiple infections, with no other co-infections detected. We named these 106 patients group-A CFS. Eighty-six of these 106 group-A CFS patients (81% had elevated EBV early antibody, early antigen (diffuse, serum titers. A small group of six patients in the group-A EBV subset of CFS, additionally, had repetitive elevated-serum titers of antibody to the early lytic replication-encoded proteins, EBV dUTPase, and EBV DNA polymerase. The presence of these serum antibodies to EBV dUTPase and EBV DNA polymerase indicated EBV abortive lytic replication in these 6 CFS patients. None of 20 random control people (age- and sex-matched, with blood drawn at a commercial laboratory had elevated serum titers of antibody to EBV dUTPase or EBV DNA polymerase (P < 0.01. This finding needs verification in a larger group of EBV CFS subset patients, but if corroborated, it may represent a molecular marker for diagnosing the EBV subset of CFS. We review evidence that EBV abortive lytic replication with unassembled viral proteins in the blood may be the same in infectious mononucleosis (IM and a subset of CFS. EBV-abortive lytic replication in tonsil plasma cells is dominant in IM. No complete lytic virion is in the blood of IM or CFS patients. Complications of CFS and IM include cardiomyopathy and encephalopathy. Circulating abortive lytic-encoded EBV proteins (eg, EBV dUTPase, EBV DNA polymerase, and others may be common to IM and CFS. The intensity and duration of the circulating EBV-encoded proteins might differentiate the IM and EBV subsets of CFS

  14. Palmitoylation of the immunity related GTPase, Irgm1: impact on membrane localization and ability to promote mitochondrial fission.

    Directory of Open Access Journals (Sweden)

    Stanley C Henry

    Full Text Available The Immunity-Related GTPases (IRG are a family of large GTPases that mediate innate immune responses. Irgm1 is particularly critical for immunity to bacteria and protozoa, and for inflammatory homeostasis in the intestine. Although precise functions for Irgm1 have not been identified, prior studies have suggested roles in autophagy/mitophagy, phagosome remodeling, cell motility, and regulating the activity of other IRG proteins. These functions ostensibly hinge on the ability of Irgm1 to localize to intracellular membranes, such as those of the Golgi apparatus and mitochondria. Previously, it has been shown that an amphipathic helix, the αK helix, in the C-terminal portion of the protein partially mediates membrane binding. However, in absence of αK, there is still substantial binding of Irgm1 to cellular membranes, suggesting the presence of other membrane binding motifs. In the current work, an additional membrane localization motif was found in the form of palmitoylation at a cluster of cysteines near the αK. An Irgm1 mutant possessing alanine to cysteine substitutions at these amino acids demonstrated little residual palmitoylation, yet it displayed only a small decrease in localization to the Golgi and mitochondria. In contrast, a mutant containing the palmitoylation mutations in combination with mutations disrupting the amphipathic character of the αK displayed a complete loss of apparent localization to the Golgi and mitochondria, as well as an overall loss of association with cellular membranes in general. Additionally, Irgm1 was found to promote mitochondrial fission, and this function was undermined in Irgm1 mutants lacking the palmitoylation domain, and to a greater extent in those lacking the αK, or the αK and palmitoylation domains combined. Our data suggest that palmitoylation together with the αK helix firmly anchor Irgm1 in the Golgi and mitochondria, thus facilitating function of the protein.

  15. Immunology: Is Actin at the Lytic Synapse a Friend or a Foe?

    Science.gov (United States)

    Hammer, John A

    2018-02-19

    Cytotoxic T cells and natural killer cells defend us against disease by secreting lytic granules. Whether actin facilitates or thwarts lytic granule secretion has been an open question. Recent results now indicate that the answer depends on the maturation stage of the immune cell-target cell contact. Published by Elsevier Ltd.

  16. Lytic effects of mixed micelles of fatty acids and bile acids

    NARCIS (Netherlands)

    Lapré, J. A.; Termont, D. S.; Groen, A. K.; van der Meer, R.

    1992-01-01

    It has been hypothesized that bile acids and fatty acids promote colon cancer. A proposed mechanism is a lytic effect of these surfactants on colonic epithelium, resulting in a compensatory proliferation of colonic cells. To investigate the first step of this hypothesis, we studied the lytic

  17. Unprecedented evidence for high viral abundance and lytic activity in coral reef waters of the South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Jérôme P. Payet

    2014-09-01

    Full Text Available Despite nutrient-depleted conditions, coral reef waters harbor abundant and diverse microbes; as major agents of microbial mortality, viruses are likely to influence microbial processes in these ecosystems. However, little is known about marine viruses in these rapidly changing ecosystems. Here we examined spatial and short-term temporal variability in marine viral abundance and viral lytic activity across various reef habitats surrounding Moorea Island (French Polynesia in the South Pacific. Water samples were collected along 4 regional cross-reef transects and during a time-series in Opunohu Bay. Results revealed high viral abundance (range: 5.6 x 106 – 3.6 x 107 viruses ml-1 and lytic viral production (range: 1.5 x 109 – 9.2 x 1010 viruses l-1 d-1. Flow cytometry revealed that viral assemblages were composed of three subsets that each displayed distinct spatiotemporal relationships with nutrient concentrations and autotrophic and heterotrophic microbial abundances. The results highlight dynamic shifts in viral community structure and imply that each of these three subsets is ecologically important and likely to infect distinct microbial hosts in reef waters. Based on viral-reduction approach, we estimate that lytic viruses were responsible for the removal of ca. 24% to 367% of bacterial standing stock d-1 and the release of ca. 1.1 to 62 µg of organic carbon l-1 d-1 in reef waters. Overall, this work demonstrates the highly dynamic distribution of viruses and their critical roles in controlling microbial mortality and nutrient cycling in coral reef water ecosystems.

  18. Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii.

    Science.gov (United States)

    Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

    2016-01-01

    Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii*

    Science.gov (United States)

    Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

    2016-01-01

    Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. PMID:26518878

  20. Loss of Function Mutation in the Palmitoyl-Transferase HHAT Leads to Syndromic 46,XY Disorder of Sex Development by Impeding Hedgehog Protein Palmitoylation and Signaling

    Science.gov (United States)

    Makrythanasis, Periklis; Bernard, Pascal; Kurosaka, Hiroshi; Vannier, Anne; Thauvin-Robinet, Christel; Borel, Christelle; Mazaud-Guittot, Séverine; Rolland, Antoine; Desdoits-Lethimonier, Christèle; Guipponi, Michel; Zimmermann, Céline; Stévant, Isabelle; Kuhne, Françoise; Conne, Béatrice; Santoni, Federico; Lambert, Sandy; Huet, Frederic; Mugneret, Francine; Jaruzelska, Jadwiga; Faivre, Laurence; Wilhelm, Dagmar; Jégou, Bernard; Trainor, Paul A.; Resh, Marilyn D.; Antonarakis, Stylianos E.; Nef, Serge

    2014-01-01

    The Hedgehog (Hh) family of secreted proteins act as morphogens to control embryonic patterning and development in a variety of organ systems. Post-translational covalent attachment of cholesterol and palmitate to Hh proteins are critical for multimerization and long range signaling potency. However, the biological impact of lipid modifications on Hh ligand distribution and signal reception in humans remains unclear. In the present study, we report a unique case of autosomal recessive syndromic 46,XY Disorder of Sex Development (DSD) with testicular dysgenesis and chondrodysplasia resulting from a homozygous G287V missense mutation in the hedgehog acyl-transferase (HHAT) gene. This mutation occurred in the conserved membrane bound O-acyltransferase (MBOAT) domain and experimentally disrupted the ability of HHAT to palmitoylate Hh proteins such as DHH and SHH. Consistent with the patient phenotype, HHAT was found to be expressed in the somatic cells of both XX and XY gonads at the time of sex determination, and Hhat loss of function in mice recapitulates most of the testicular, skeletal, neuronal and growth defects observed in humans. In the developing testis, HHAT is not required for Sertoli cell commitment but plays a role in proper testis cord formation and the differentiation of fetal Leydig cells. Altogether, these results shed new light on the mechanisms of action of Hh proteins. Furthermore, they provide the first clinical evidence of the essential role played by lipid modification of Hh proteins in human testicular organogenesis and embryonic development. PMID:24784881

  1. The lytic transglycosylase MltB connects membrane homeostasis and in vivo fitness of Acinetobacter baumannii.

    Science.gov (United States)

    Crépin, Sébastien; Ottosen, Elizabeth N; Peters, Katharina; Smith, Sara N; Himpsl, Stephanie D; Vollmer, Waldemar; Mobley, Harry L T

    2018-06-08

    Acinetobacter baumannii has emerged as a leading nosocomial pathogen, infecting a wide range of anatomic sites including the respiratory tract and the bloodstream. In addition to being multi-drug resistant, little is known about the molecular basis of A. baumannii pathogenesis. To better understand A. baumannii virulence, a combination of a transposon-sequencing (TraDIS) screen and the neutropenic mouse model of bacteremia was used to identify the full set of fitness genes required during bloodstream infection. The lytic transglycosylase MltB was identified as a critical fitness factor. MltB cleaves the MurNAc-GlcNAc bond of peptidoglycan, which leads to cell wall remodeling. Here we show that MltB is part of a complex network connecting resistance to stresses, membrane homeostasis, biogenesis of pili and in vivo fitness. Indeed, inactivation of mltB not only impaired resistance to serum complement, cationic antimicrobial peptides and oxygen species, but also altered the cell envelope integrity, activated the envelope stress response, drastically reduced the number of pili at the cell surface and finally, significantly decreased colonization of both the bloodstream and the respiratory tract. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

  2. Attenuation of hedgehog acyltransferase-catalyzed sonic Hedgehog palmitoylation causes reduced signaling, proliferation and invasiveness of human carcinoma cells

    DEFF Research Database (Denmark)

    Konitsiotis, Antonios D; Chang, Shu-Chun; Jovanović, Biljana

    2014-01-01

    ) cell line PANC-1 and transfected HEK293a cells Hhat localized to the endoplasmic reticulum. siRNA knockdown showed that Hhat is required for Sonic hedgehog (Shh) palmitoylation, for its assembly into high molecular weight extracellular complexes and for functional activity. Hhat knockdown inhibited Hh...

  3. Regioselective Palmitoylation of 9-(2,3-Dihydroxy-propyl)adenine Catalyzed by a Glycopolymer-enzyme Conjugate

    Czech Academy of Sciences Publication Activity Database

    Brabcová, Jana; Blažek, Jiří; Krečmerová, Marcela; Vondrášek, Jiří; Palomo, J. M.; Zarevúcka, Marie

    2016-01-01

    Roč. 21, č. 5 (2016), č. článku 648. ISSN 1420-3049 Grant - others:AV ČR(CZ) M200551203 Institutional support: RVO:61388963 Keywords : regioselectivity * palmitoylation * glycosylation * chemical modification Subject RIV: CE - Biochemistry Impact factor: 2.861, year: 2016 http://www.mdpi.com/1420-3049/21/5/648/htm

  4. Genomic analysis of Bacillus subtilis lytic bacteriophage ϕNIT1 capable of obstructing natto fermentation carrying genes for the capsule-lytic soluble enzymes poly-γ-glutamate hydrolase and levanase.

    Science.gov (United States)

    Ozaki, Tatsuro; Abe, Naoki; Kimura, Keitarou; Suzuki, Atsuto; Kaneko, Jun

    2017-01-01

    Bacillus subtilis strains including the fermented soybean (natto) starter produce capsular polymers consisting of poly-γ-glutamate and levan. Capsular polymers may protect the cells from phage infection. However, bacteriophage ϕNIT1 carries a γ-PGA hydrolase gene (pghP) that help it to counteract the host cell's protection strategy. ϕNIT had a linear double stranded DNA genome of 155,631-bp with a terminal redundancy of 5,103-bp, containing a gene encoding an active levan hydrolase. These capsule-lytic enzyme genes were located in the possible foreign gene cluster regions between central core and terminal redundant regions, and were expressed at the late phase of the phage lytic cycle. All tested natto origin Spounavirinae phages carried both genes for capsule degrading enzymes similar to ϕNIT1. A comparative genomic analysis revealed the diversity among ϕNIT1 and Bacillus phages carrying pghP-like and levan-hydrolase genes, and provides novel understanding on the acquisition mechanism of these enzymatic genes.

  5. Influence of palmitoyl pentapeptide and Ceramide III B on the droplet size of nanoemulsion

    Science.gov (United States)

    Sondari, Dewi; Haryono, Agus; Harmami, Sri Budi; Randy, Ahmad

    2010-05-01

    The influence of the Palmitoyl Pentapeptide (PPp) and Ceramide IIIB (Cm III B) as active ingredients on the droplet size of nano-emulsion was studied using different kinds of oil (avocado oil, sweet almond oil, jojoba oil, mineral oil and squalene). The formation of nano-emulsions were prepared in water mixed non ionic surfactant/oils system using the spontaneous emulsification mechanism. The aqueous solution, which consist of water and Tween® 20 as a hydrophilic surfactant was mixed homogenously. The organic solution, which consist of oil and Span® 80 as a lipophilic surfactant was mixed homogenously in ethanol. Ethanol was used as a water miscible solvent, which can help the formation of nano-emulsion. The oil phase (containing the blend of surfactant Span® 80, ethanol, oil and active ingredient) and the aqueous phase (containing water and Tween® 20) were separately prepared at room temperatures. The oil phase was slowly added into aqueous phase under continuous mechanical agitation (18000 rpm). All samples were subsequently homogenized with Ultra-Turrax for 30 minutes. The characterizations of nano-emulsion were carried out using photo-microscope and particle size analyzer. Addition of active ingredients on the formation of nano-emulsion gave smallest droplet size compared without active ingredients addition on the formation of nano-emulsion. Squalene oil with Palmitoyl Pentapeptide (PPm) and Ceramide IIIB (Cm IIIB) gave smallest droplet size (184.0 nm) compared without Palmitoyl Pentapeptide and Ceramide IIIB (214.9 nm), however the droplets size of the emulsion prepared by the other oils still in the range of nano-emulsion (below 500 nm). The stability of nano-emulsion was observed using two methods. In one method, the stability of nano-emulsion was observed for three months at temperature of 5°C and 50°C, while in the other method, the stability nano-emulsion was observed by centrifuged at 12000 rpm for 30 minutes. Nanoemulsion with active ingredient

  6. The role of oxidative stress in EBV lytic reactivation, radioresistance and the potential preventive and therapeutic implications.

    Science.gov (United States)

    Hu, Jianmin; Li, Hongde; Luo, Xiangjian; Li, Yueshuo; Bode, Ann; Cao, Ya

    2017-11-01

    Epstein-Barr virus (EBV) is an important cancer causing virus. Cancer associated with EBV account for approximately 1.5% of all cancers, and represent 1.8% of all cancer deaths worldwide. EBV reactivation plays an important role in the development of EBV-related diseases and is closely related with patients' survival and clinical stages of EBV-related cancers. The therapy regarding to EBV-related cancers is very urgent, especially in endemic areas. Generating oxidative stress is a critical mechanism by which host cells defend against infection by virus. In addition, ROS-mediated oxidative stress plays a significant but paradoxical role acting as a "double-edged sword" to regulate cellular response to radiation, which is the main therapy strategy for EBV-related cancers, especially nasopharyngeal carcinoma. Therefore, in this review we primarily discuss the possible interplay among the oxidative stress, EBV lytic reactivation and radioresistance. Understanding the role of oxidative stress in EBV lytic reactivation and radioresistance will assist in the development of effective strategies for prevention and treatment of EBV-related cancers. © 2017 UICC.

  7. In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

    International Nuclear Information System (INIS)

    Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B.

    2007-01-01

    The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells

  8. Factors affecting the palmitoyl-coenzyme A desaturase of Saccharomyces cerevisiae

    Science.gov (United States)

    Klein, H. P.; Volkmann, C. M.

    1975-01-01

    The activity and stability of the palmitoyl-coenzyme A (CoA) desaturase complex of Saccharomyces cerevisiae was influenced by several factors. Cells, grown nonaerobically and then incubated with glucose, either in air or under N2, showed a marked increase in desaturase activity. Cycloheximide, added during such incubations, prevented the increase in activity, suggesting de novo synthesis. The stability of the desaturase from cells grown nonaerobically was affected by subsequent treatment of the cells; enzyme from freshly harvested cells, or from cells that were then shaken under nitrogen, readily lost activity upon washing or during density gradient analysis, whereas aerated cells, in the presence or absence of glucose, yielded stable enzyme preparations. The loss of activity in nonaerobic preparations could be reversed by adding soluble supernatant from these homogenates and could be prevented by growing the cells in the presence of palmitoleic acid and ergosterol, but not with several other lipids tested.

  9. Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan.

    Science.gov (United States)

    Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz Ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad

    2015-01-01

    This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.

  10. Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan

    Science.gov (United States)

    Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad

    2015-01-01

    Abstract This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract. PMID:26691463

  11. Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki.

    Directory of Open Access Journals (Sweden)

    Dann Turner

    Full Text Available Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA under the accession number LN890663.

  12. Navigating barriers: the challenge of directed secretion at the natural killer cell lytic immunological synapse.

    Science.gov (United States)

    Sanborn, Keri B; Orange, Jordan S

    2010-05-01

    Natural killer (NK) cells have an inherent ability to recognize and destroy a wide array of cells rendered abnormal by stress or disease. NK cells can kill a targeted cell by forming a tight interface-the lytic immunological synapse. This represents a dynamic molecular arrangement that over time progresses through a series of steps to ultimately deliver the contents of specialized organelles known as lytic granules. In order to mediate cytotoxicity, the NK cell faces the challenge of mobilizing the lytic granules, polarizing them to the targeted cell, facilitating their approximation to the NK cell membrane, and releasing their contents. This review is focused upon the final steps in accessing function through the lytic immunological synapse.

  13. Liposome Disruption Assay to Examine Lytic Properties of Biomolecules.

    Science.gov (United States)

    Jimah, John R; Schlesinger, Paul H; Tolia, Niraj H

    2017-08-05

    Proteins may have three dimensional structural or amino acid features that suggest a role in targeting and disrupting lipids within cell membranes. It is often necessary to experimentally investigate if these proteins and biomolecules are able to disrupt membranes in order to conclusively characterize the function of these biomolecules. Here, we describe an in vitro assay to evaluate the membrane lytic properties of proteins and biomolecules. Large unilamellar vesicles (liposomes) containing carboxyfluorescein at fluorescence-quenching concentrations are treated with the biomolecule of interest. A resulting increase in fluorescence due to leakage of the dye from liposomes and subsequent dilution in the buffer demonstrates that the biomolecule is sufficient for disrupting liposomes and membranes. Additionally, since liposome disruption may occur via pore-formation or via general solubilization of lipids similar to detergents, we provide a method to distinguish between these two mechanisms. Pore-formation can be identified and evaluated by examining the blockade of carboxyfluorescein release with dextran molecules that fit the pore. The methods described here were used to determine that the malaria vaccine candidate CelTOS and proapoptotic Bax disrupt liposomes by pore formation (Saito et al. , 2000; Jimah et al. , 2016). Since membrane lipid binding by a biomolecule precedes membrane disruption, we recommend the companion protocol: Jimah et al. , 2017.

  14. Antibacterial Efficacy of Lytic Bacteriophages against Antibiotic-Resistant Klebsiella Species

    Directory of Open Access Journals (Sweden)

    M. Khajeh Karamoddini

    2011-01-01

    Full Text Available Bacterial resistance to antibiotics is a leading and highly prevalent problem in the treatment of infectious diseases. Bacteriophages (phages appear to be effective and safe alternatives for the treatment of resistant infections because of their specificity for bacterial species and lack of infectivity in eukaryotic cells. The present study aimed to isolate bacteriophages against Klebsiella spp. and evaluate their efficacy against antibiotic-resistant species. Seventy-two antibiotic-resistant Klebsiella spp. were isolated from samples of patients who referred to the Ghaem Hospital (Mashhad, Iran. Lytic bacteriophages against Klebsiella spp. were isolated from wastewater of the septic tank of the same hospital. Bactericidal activity of phages against resistant Klebsiella spp. was tested in both liquid (tube method; after 1 and 24 h of incubation and solid (double-layer agar plate method; after 24 h of incubation phases. In each method, three different concentrations of bacteriophages (low: 107 PFU/mL were used. Bacteriophages showed promising bactericidal activity at all assessed concentrations, regardless of the test method and duration of incubation. Overall, bactericidal effects were augmented at higher concentrations. In the tube method, higher activity was observed after 24 h of incubation compared to the 1-h incubation. The bactericidal effects were also higher in the tube method compared to the double-layer agar plate method after 24 h of incubation. The findings of the present study suggest that bacteriophages possess effective bactericidal activity against resistant Klebsiella spp. These bactericidal activities are influenced by phage concentration, duration of incubation, and test method.

  15. Essential role of flotillin-1 palmitoylation in the intracellular localization and signaling function of IGF-1 receptor.

    Science.gov (United States)

    Jang, Donghwan; Kwon, Hayeong; Jeong, Kyuho; Lee, Jaewoong; Pak, Yunbae

    2015-06-01

    Here, we explored flotillin-1-mediated regulation of insulin-like growth factor-1 (IGF-1) signaling. Flotillin-1-deficient cells exhibited a reduction in the activation of IGF-1 receptor (IGF-1R), ERK1/2 and Akt pathways, and the transcriptional activation of Elk-1 and the proliferation in response to IGF-1 were reduced in these cells. We found that IGF-1-independent flotillin-1 palmitoylation at Cys34 in the endoplasmic reticulum (ER) was required for the ER exit and the plasma membrane localization of flotillin-1 and IGF-1R. IGF-1-dependent depalmitoylation and repalmitoylation of flotillin-1 sustained tyrosine kinase activation of the plasma-membrane-targeted IGF-1R. Dysfunction and blocking the turnover of flotillin-1 palmitoylation abrogated cancer cell proliferation after IGF-1R signaling activation. Our data show that flotillin-1 palmitoylation is a new mechanism by which the intracellular localization and activation of IGF-1R are controlled. © 2015. Published by The Company of Biologists Ltd.

  16. Discovery and industrial applications of lytic polysaccharide mono-oxygenases.

    Science.gov (United States)

    Johansen, Katja S

    2016-02-01

    The recent discovery of copper-dependent lytic polysaccharide mono-oxygenases (LPMOs) has opened up a vast area of research covering several fields of application. The biotech company Novozymes A/S holds patents on the use of these enzymes for the conversion of steam-pre-treated plant residues such as straw to free sugars. These patents predate the correct classification of LPMOs and the striking synergistic effect of fungal LPMOs when combined with canonical cellulases was discovered when fractions of fungal secretomes were evaluated in industrially relevant enzyme performance assays. Today, LPMOs are a central component in the Cellic CTec enzyme products which are used in several large-scale plants for the industrial production of lignocellulosic ethanol. LPMOs are characterized by an N-terminal histidine residue which, together with an internal histidine and a tyrosine residue, co-ordinates a single copper atom in a so-called histidine brace. The mechanism by which oxygen binds to the reduced copper atom has been reported and the general mechanism of copper-oxygen-mediated activation of carbon is being investigated in the light of these discoveries. LPMOs are widespread in both the fungal and the bacterial kingdoms, although the range of action of these enzymes remains to be elucidated. However, based on the high abundance of LPMOs expressed by microbes involved in the decomposition of organic matter, the importance of LPMOs in the natural carbon-cycle is predicted to be significant. In addition, it has been suggested that LPMOs play a role in the pathology of infectious diseases such as cholera and to thus be relevant in the field of medicine. © 2016 Authors; published by Portland Press Limited.

  17. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries

    Directory of Open Access Journals (Sweden)

    Anil Kumar Gupta

    2016-01-01

    Full Text Available Background: The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. Materials and Methods: 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid, ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst ( n = 3, aneurysmal bone cyst ( n = 3, giant cell tumor ( n = 9, fibrous dysplasia ( n = 12, chondromyxoid fibroma, chondroma, nonossifying fibroma ( n = 1 each, tubercular osteomyelitis ( n = 7, and chronic pyogenic osteomyelitis ( n = 5. The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Results: Quantitative assessment based on the criteria of Sethi et al. (1993 was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture. We

  18. Coordination of KSHV Latent and Lytic Gene Control by CTCF-Cohesin Mediated Chromosome Conformation

    Science.gov (United States)

    Kang, Hyojeung; Wiedmer, Andreas; Yuan, Yan; Robertson, Erle; Lieberman, Paul M.

    2011-01-01

    Herpesvirus persistence requires a dynamic balance between latent and lytic cycle gene expression, but how this balance is maintained remains enigmatic. We have previously shown that the Kaposi's Sarcoma-Associated Herpesvirus (KSHV) major latency transcripts encoding LANA, vCyclin, vFLIP, v-miRNAs, and Kaposin are regulated, in part, by a chromatin organizing element that binds CTCF and cohesins. Using viral genome-wide chromatin conformation capture (3C) methods, we now show that KSHV latency control region is physically linked to the promoter regulatory region for ORF50, which encodes the KSHV immediate early protein RTA. Other linkages were also observed, including an interaction between the 5′ and 3′ end of the latency transcription cluster. Mutation of the CTCF-cohesin binding site reduced or eliminated the chromatin conformation linkages, and deregulated viral transcription and genome copy number control. siRNA depletion of CTCF or cohesin subunits also disrupted chromosomal linkages and deregulated viral latent and lytic gene transcription. Furthermore, the linkage between the latent and lytic control region was subject to cell cycle fluctuation and disrupted during lytic cycle reactivation, suggesting that these interactions are dynamic and regulatory. Our findings indicate that KSHV genomes are organized into chromatin loops mediated by CTCF and cohesin interactions, and that these inter-chromosomal linkages coordinate latent and lytic gene control. PMID:21876668

  19. Temperate and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria.

    Science.gov (United States)

    Yosef, Ido; Manor, Miriam; Kiro, Ruth; Qimron, Udi

    2015-06-09

    The increasing threat of pathogen resistance to antibiotics requires the development of novel antimicrobial strategies. Here we present a proof of concept for a genetic strategy that aims to sensitize bacteria to antibiotics and selectively kill antibiotic-resistant bacteria. We use temperate phages to deliver a functional clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) system into the genome of antibiotic-resistant bacteria. The delivered CRISPR-Cas system destroys both antibiotic resistance-conferring plasmids and genetically modified lytic phages. This linkage between antibiotic sensitization and protection from lytic phages is a key feature of the strategy. It allows programming of lytic phages to kill only antibiotic-resistant bacteria while protecting antibiotic-sensitized bacteria. Phages designed according to this strategy may be used on hospital surfaces and hand sanitizers to facilitate replacement of antibiotic-resistant pathogens with sensitive ones.

  20. Effects of truncation of the peptide chain on the secondary structure and bioactivities of palmitoylated anoplin.

    Science.gov (United States)

    Salas, Remmer L; Garcia, Jan Kathryne D L; Miranda, Ana Carmela R; Rivera, Windell L; Nellas, Ricky B; Sabido, Portia Mahal G

    2018-06-01

    Anoplin (GLLKRIKTLL-NH 2 ) is of current interest due to its short sequence and specificity towards bacteria. Recent studies on anoplin have shown that truncation and acylation compromises its antimicrobial activity and specificity, respectively. In this study, truncated analogues (pal-ano-9 to pal-ano-5) of palmitoylated anoplin (pal-anoplin) were synthesized to determine the effects of C-truncation on its bioactivities. Moreover, secondary structure of each analogue using circular dichroism (CD) spectroscopy was determined to correlate with bioactivities. Interestingly, pal-anoplin, pal-ano-9 and pal-ano-6 were helical in water, unlike anoplin. In contrast, pal-ano-8, pal-ano-7 and pal-ano-5, with polar amino acid residues at the C-terminus, were random coil in water. Nevertheless, all the peptides folded into helical structures in 30% trifluoroethanol/water (TFE/H 2 O) except for the shortest analogue pal-ano-5. Hydrophobicity played a significant role in the enhancement of activity against bacteria E. coli and S. aureus as all lipopeptides including the random coil pal-ano-5 were more active than the parent anoplin. Meanwhile, the greatest improvement in activity against the fungus C. albicans was observed for pal-anoplin analogues (pal-ano-9 and pal-ano-6) that were helical in water. Although, hydrophobicity is a major factor in the secondary structure and antimicrobial activity, it appears that the nature of amino acids at the C-terminus also influence folding of lipopeptides in water and its antifungal activity. Moreover, the hemolytic activity of the analogues was found to correlate with hydrophobicity, except for the least hemolytic, pal-ano-5. Since most of the analogues are more potent and shorter than anoplin, they are promising drug candidates for further development. Copyright © 2018. Published by Elsevier Inc.

  1. Magnetic responsive of paclitaxel delivery system based on SPION and palmitoyl chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Mansouri, Mona [Department of Biomedical Engineering, Amirkabir University of Technology, P.O. Box: 15875/4413, Tehran 159163/4311 (Iran, Islamic Republic of); Nazarpak, Masoumeh Haghbin, E-mail: haghbin@aut.ac.ir [New Technologies Research Center (NTRC), Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of); Solouk, Atefeh [Department of Biomedical Engineering, Amirkabir University of Technology, P.O. Box: 15875/4413, Tehran 159163/4311 (Iran, Islamic Republic of); Akbari, Somaye [Department of Textile Engineering, Amirkabir University of Technology, P.O. Box: 15875/4413, Tehran 15916/34311 (Iran, Islamic Republic of); Hasani-Sadrabadi, Mohammad Mahdi [Parker H. Petit Institute for Bioengineering and Bioscience, G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0295 (United States)

    2017-01-01

    Concerns over cancer treatment have largely focused on chemotherapy and its consequent side effects. Utilizing nanocarriers is thought to be a panacea for mitigating the limitations of chemotherapy, and increasing its safety and efficacy. Magnetically driven Paclitaxel delivery systems are among the commonly investigated types of nanocarriers over the last two decades. In this context, we tried to highlight the application of an AC magnetic field and validate its consequential effects on drug delivery pattern and cell death in such nanodevices. So the aim of this study is to develop an appropriate matrix (Palmitoyl chitosan) co-encapsulated with superparamagnetic iron oxide nanoparticles (SPIONs) and anticancer drug, Paclitaxel (PTX) via the nanoprecipitation process. Synthesized nanoparticles were characterized by Dynamic Light Scattering (DLS) and their magnetic properties were investigated by Vibrating Sample Magnetometer (VSM). At initial loading of 10 wt% Paclitaxel, the maximum loading efficiency of nanoparticles with and without SPIONs was in the range of 69% and 72.3%, respectively. In addition, in vitro release data revealed that by the application of a magnetic field, release kinetic changed to the magnetic responsive pattern. Encapsulating anticancer drug in a synthesized nanosystem not only increased the amount of drug in cancer cells but also enhanced cell death (MCF-7) due to hyperthermic effects of SPIONs in the presence of an external magnetic field. In summary, these findings indicate that the resultant nanoparticles may serve as a biocompatible and biodegradable carrier for the precise delivery of powerful cytotoxic anticancer agents such as PTX. - Highlights: ●This paper focuses on using an AC magnetic field to enhance the drug entry and to increase its concentration in the cell. ●The rate of drug release is highly dependent on the amount of available pores for transporting molecules.

  2. Determination of the serine palmitoyl transferase inhibitor myriocin by electrospray and Q-trap mass spectrometry.

    Science.gov (United States)

    Campisi, Giuseppe Matteo; Signorelli, Paola; Rizzo, Jessica; Ghilardi, Claudio; Antognetti, Jacopo; Caretti, Anna; Lazarević, Jelena S; Strettoi, Enrica; Novelli, Elena; Ghidoni, Riccardo; Rubino, Federico Maria; Paroni, Rita

    2017-12-01

    Myriocin is a potent inhibitor of serine-palmitoyl-transferase, the first and rate-determining enzyme in the sphingolipids biosynthetic pathway. This study developed, validated and applied a LC-MS/MS method to measure myriocin in minute specimens of animal tissue. The chemical analog 14-OH-myriocin was used as the internal standard. The two molecules were extracted from the tissue homogenate by solid-phase extraction, separated by gradient reversed-phase liquid chromatography and measured by negative ion electrospray mass spectrometry in the triple quadrupole. Detection was accomplished by multiple reaction monitoring, employing the most representative transitions, 400@104 and 402@104 for myriocin and 14-OH-myriocin, respectively. The typical limit of detection and lower limit of quantitation of the optimized method were 0.9 pmol/mL (~0.016 pmol injected) and 2.3 pmol/mL, respectively, and the method was linear up to 250 pmol/mL range (r 2  = 0.9996). The intra- and between-day repeatability afforded a coefficient of variation ≤7.0%. Applications included quantification of myriocin in mouse lungs after 24 h from administration of ~4 nmol by intra-tracheal delivery. Measured levels ranged from 4.11 (median; 2.3-7.4 IQR, n = 4) to 11.7 (median; 7.6-22.7 interquartile range (IQR), n = 6) pmol/lung depending on the different formulations used. Myriocin was also measured in retinas of mice treated by intravitreal injection and ranged from 0.045 (less than the limit of detection) to 0.35 pmol/retina. Copyright © 2017 John Wiley & Sons, Ltd.

  3. A novel mechanism of regulating breast cancer cell migration via palmitoylation-dependent alterations in the lipid raft affiliation of CD44.

    Science.gov (United States)

    Babina, Irina S; McSherry, Elaine A; Donatello, Simona; Hill, Arnold D K; Hopkins, Ann M

    2014-02-10

    Most breast cancer-related deaths result from metastasis, a process involving dynamic regulation of tumour cell adhesion and migration. The adhesion protein CD44, a key regulator of cell migration, is enriched in cholesterol-enriched membrane microdomains termed lipid rafts. We recently reported that raft affiliation of CD44 negatively regulates interactions with its migratory binding partner ezrin. Since raft affiliation is regulated by post-translational modifications including palmitoylation, we sought to establish the contribution of CD44 palmitoylation and lipid raft affiliation to cell migration. Recovery of CD44 and its binding partners from raft versus non-raft membrane microdomains was profiled in non-migrating and migrating breast cancer cell lines. Site-directed mutagenesis was used to introduce single or double point mutations into both CD44 palmitoylation sites (Cys286 and Cys295), whereupon the implications for lipid raft recovery, phenotype, ezrin co-precipitation and migratory behaviour was assessed. Finally CD44 palmitoylation status and lipid raft affiliation was assessed in primary cultures from a small panel of breast cancer patients. CD44 raft affiliation was increased during migration of non-invasive breast cell lines, but decreased during migration of highly-invasive breast cells. The latter was paralleled by increased CD44 recovery in non-raft fractions, and exclusive non-raft recovery of its binding partners. Point mutation of CD44 palmitoylation sites reduced CD44 raft affiliation in invasive MDA-MB-231 cells, increased CD44-ezrin co-precipitation and accordingly enhanced cell migration. Expression of palmitoylation-impaired (raft-excluded) CD44 mutants in non-invasive MCF-10a cells was sufficient to reversibly induce the phenotypic appearance of epithelial-to-mesenchymal transition and to increase cell motility. Interestingly, cell migration was associated with temporal reductions in CD44 palmitoylation in wild-type breast cells. Finally

  4. Adoptive transfer of EBV specific CD8+ T cell clones can transiently control EBV infection in humanized mice.

    Directory of Open Access Journals (Sweden)

    Olga Antsiferova

    2014-08-01

    Full Text Available Epstein Barr virus (EBV infection expands CD8+ T cells specific for lytic antigens to high frequencies during symptomatic primary infection, and maintains these at significant numbers during persistence. Despite this, the protective function of these lytic EBV antigen-specific cytotoxic CD8+ T cells remains unclear. Here we demonstrate that lytic EBV replication does not significantly contribute to virus-induced B cell proliferation in vitro and in vivo in a mouse model with reconstituted human immune system components (huNSG mice. However, we report a trend to reduction of EBV-induced lymphoproliferation outside of lymphoid organs upon diminished lytic replication. Moreover, we could demonstrate that CD8+ T cells against the lytic EBV antigen BMLF1 can eliminate lytically replicating EBV-transformed B cells from lymphoblastoid cell lines (LCLs and in vivo, thereby transiently controlling high viremia after adoptive transfer into EBV infected huNSG mice. These findings suggest a protective function for lytic EBV antigen-specific CD8+ T cells against EBV infection and against virus-associated tumors in extra-lymphoid organs. These specificities should be explored for EBV-specific vaccine development.

  5. Impact of novel palmitoylated prolactin-releasing peptide analogs on metabolic changes in mice with diet-induced obesity.

    Directory of Open Access Journals (Sweden)

    Veronika Pražienková

    Full Text Available Analogs of anorexigenic neuropeptides, such as prolactin-releasing peptide (PrRP, have a potential as new anti-obesity drugs. In our previous study, palmitic acid attached to the N-terminus of PrRP enabled its central anorexigenic effects after peripheral administration. In this study, two linkers, γ-glutamic acid at Lys11 and a short, modified polyethylene glycol at the N-terminal Ser and/or Lys11, were applied for the palmitoylation of PrRP31 to improve its bioavailability. These analogs had a high affinity and activation ability to the PrRP receptor GPR10 and the neuropeptide FF2 receptor, as well as short-term anorexigenic effect similar to PrRP palmitoylated at the N-terminus. Two-week treatment with analogs that were palmitoylated through linkers to Lys11 (analogs 1 and 2, but not with analog modified both at the N-terminus and Lys11 (analog 3 decreased body and liver weights, insulin, leptin, triglyceride, cholesterol and free fatty acid plasma levels in a mouse model of diet-induced obesity. Moreover, the expression of uncoupling protein-1 was increased in brown fat suggesting an increase in energy expenditure. In addition, treatment with analogs 1 and 2 but not analog 3 significantly decreased urinary concentrations of 1-methylnicotinamide and its oxidation products N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-3-carboxamide, as shown by NMR-based metabolomics. This observation confirmed the previously reported increase in nicotinamide derivatives in obesity and type 2 diabetes mellitus and the effectiveness of analogs 1 and 2 in the treatment of these disorders.

  6. Palmitoylated claudin7 captured in glycolipid-enriched membrane microdomains promotes metastasis via associated transmembrane and cytosolic molecules

    OpenAIRE

    Thuma, Florian; Heiler, Sarah; Schn?lzer, Martina; Z?ller, Margot

    2016-01-01

    In epithelial cells claudin7 (cld7) is a major component of tight junctions, but is also recovered from glycolipid-enriched membrane microdomains (GEM). In tumor cells, too, cld7 exists in two stages. Only GEM-located cld7, which is palmitoylated, promotes metastasis. Searching for the underlying mechanism(s) revealed the following. The metastatic capacity of the rat pancreatic adenocarcinoma cell line ASML is lost by a knockdown (kd) of cld7 and is not regained by rescuing cld7 with a mutate...

  7. Cellular corepressor TLE2 inhibits replication-and-transcription- activator-mediated transactivation and lytic reactivation of Kaposi's sarcoma-associated herpesvirus.

    Science.gov (United States)

    He, Zhiheng; Liu, Yunhua; Liang, Deguang; Wang, Zhuo; Robertson, Erle S; Lan, Ke

    2010-02-01

    Replication and transcription activator (RTA) encoded by open reading frame 50 (ORF50) of Kaposi's sarcoma-associated herpesvirus (KSHV) is essential and sufficient to initiate lytic reactivation. RTA activates its target genes through direct binding with high affinity to its responsive elements or by interaction with cellular factors, such as RBP-Jkappa, Ap-1, C/EBP-alpha, and Oct-1. In this study, we identified transducin-like enhancer of split 2 (TLE2) as a novel RTA binding protein by using yeast two-hybrid screening of a human spleen cDNA library. The interaction between TLE2 and RTA was confirmed by glutathione S-transferase (GST) binding and coimmunoprecipitation assays. Immunofluorescence analysis showed that TLE2 and RTA were colocalized in the same nuclear compartment in KSHV-infected cells. This interaction recruited TLE2 to RTA bound to its recognition sites on DNA and repressed RTA auto-activation and transactivation activity. Moreover, TLE2 also inhibited the induction of lytic replication and virion production driven by RTA. We further showed that the Q (Gln-rich), SP (Ser-Pro-rich), and WDR (Trp-Asp repeat) domains of TLE2 and the Pro-rich domain of RTA were essential for this interaction. RBP-Jkappa has been shown previously to bind to the same Pro-rich domain of RTA, and this binding can be subject to competition by TLE2. In addition, TLE2 can form a complex with RTA to access the cognate DNA sequence of the RTA-responsive element at different promoters. Intriguingly, the transcription level of TLE2 could be upregulated by RTA during the lytic reactivation process. In conclusion, we identified a new RTA binding protein, TLE2, and demonstrated that TLE2 inhibited replication and transactivation mediated by RTA. This provides another potentially important mechanism for maintenance of KSHV viral latency through interaction with a host protein.

  8. Effectiveness of lytic bacteriophages in reducing E. coli O157:H7 populations introduced through cross-contamination on fresh cut lettuce

    Science.gov (United States)

    Previous research has shown that lytic bacteriophages (phages) can kill E. coli O157:H7 on produce surfaces. The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield) at 10^8 PFU/m...

  9. Freezing and post-thaw apoptotic behaviour of cells in the presence of palmitoyl nanogold particles

    International Nuclear Information System (INIS)

    Thirumala, Sreedhar; Forman, Julianne M; Monroe, W Todd; Devireddy, Ram V

    2007-01-01

    The aim of this study was to evaluate the freezing response of HeLa and Jurkat cells in the presence of commercially available nanoparticles, NPs (Palmitoyl Nanogold[reg], Nanoprobes). The cells were incubated with NPs for either 5 min or 3 h, and a calorimeter technique was then used to generate the volumetric shrinkage response during freezing at 20 deg. C min -1 . Concomitantly, we also examined the effect of a commonly used cryoprotectant, dimethylsulfoxide, DMSO (10% v/v ratio) on the freezing response of HeLa and Jurkat cells. By fitting a model of water transport to the experimentally determined volumetric shrinkage data, the reference hydraulic conductivity, L pg (μm/min-atm) and activation energy, E Lp (kcal mol -1 ) were obtained. For HeLa cells, the values of L pg ranged from 0.08 to 0.23 μm/min-atm, while E Lp ranged from 10.9 to 37.4 kcal mol -1 . For Jurkat cells these parameter values ranged from 0.05 to 0.16 μm/min-atm and 9.5 to 35.9 kcal mol -1 . A generic optimal cooling rate equation was then used to predict the optimal rates of freezing HeLa and Jurkat cells in the presence and absence of DMSO and NPs. The post-thaw viability and apoptotic response of HeLa and Jurkat cells was further investigated by cooling cells at three rates in the presence and absence of DMSO and NPs using a commercially available controlled rate freezer. Jurkat cells treated in this manner demonstrated an increase in their adhesive properties after 18 h incubation and adhered strongly to the bottom of the culture plate. This observation prevented further analysis of Jurkat apoptotic and necrotic post-thaw responses. There was no significant effect of NPs or DMSO alone on HeLa cell viability prior to freezing. The post-thaw results from HeLa cells show that the NPs increased the measured post-freeze apoptotic response when cooled at 1 deg. C min -1 , suggesting a possible therapeutic use of NPs in cryodestructive procedures

  10. Crystal structure and mechanism of the lytic transglycosylase MltA from Escherichia coli

    NARCIS (Netherlands)

    van Straaten, Karin

    2006-01-01

    This thesis describes the determination and analysis of the 3D-structure of the lytic transglycosylase MltA from Escherichia coli by X-ray crystallography. This work aims to further increase our knowledge of the molecular details of the cleaving mechanism and the typical 1,6- anhydromuropeptide

  11. Analyzing Activities of Lytic Polysaccharide Monooxygenases by Liquid Chromatography and Mass Spectrometry

    DEFF Research Database (Denmark)

    Westereng, Bjørge; Arntzen, Magnus Ø.; Wittrup Agger, Jane

    2017-01-01

    Lytic polysaccharide monooxygenases perform oxidative cleavage of glycosidic bonds in various polysaccharides. The majority of LMPOs studied so far possess activity on either cellulose or chitin and analysis of these activities is therefore the main focus of this review. Notably, however, the num...

  12. Genetic characterization of ØVC8 lytic phage for Vibrio cholerae O1.

    Science.gov (United States)

    Solís-Sánchez, Alejandro; Hernández-Chiñas, Ulises; Navarro-Ocaña, Armando; De la Mora, Javier; Xicohtencatl-Cortes, Juan; Eslava-Campos, Carlos

    2016-03-22

    Epidemics and pandemics of cholera, a diarrheal disease, are attributed to Vibrio cholera serogroups O1 and O139. In recent years, specific lytic phages of V. cholera have been proposed to be important factors in the cyclic occurrence of cholera in endemic areas. However, the role and potential participation of lytic phages during long interepidemic periods of cholera in non-endemic regions have not yet been described. The purpose of this study was to isolate and characterize specific lytic phages of V. cholera O1 strains. Sixteen phages were isolated from wastewater samples collected at the Endhó Dam in Hidalgo State, Mexico, concentrated with PEG/NaCl, and purified by density gradient. The lytic activity of the purified phages was tested using different V. cholerae O1 and O139 strains. Phage morphology was visualized by transmission electron microscopy (TEM), and phage genome sequencing was performed using the Genome Analyzer IIx System. Genome assembly and bioinformatics analysis were performed using a set of high-throughput programs. Phage structural proteins were analyzed by mass spectrometry. Sixteen phages with lytic and lysogenic activity were isolated; only phage ØVC8 showed specific lytic activity against V. cholerae O1 strains. TEM images of ØVC8 revealed a phage with a short tail and an isometric head. The ØVC8 genome comprises linear double-stranded DNA of 39,422 bp with 50.8 % G + C. Of the 48 annotated ORFs, 16 exhibit homology with sequences of known function and several conserved domains. Bioinformatics analysis showed multiple conserved domains, including an Ig domain, suggesting that ØVC8 might adhere to different mucus substrates such as the human intestinal epithelium. The results suggest that ØVC8 genome utilize the "single-stranded cohesive ends" packaging strategy of the lambda-like group. The two structural proteins sequenced and analyzed are proteins of known function. ØVC8 is a lytic phage with specific activity against V. cholerae

  13. Noninvasive evaluation of adult onset myopathy from carnitine palmitoyl transferase II deficiency using proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Videen, J S; Haseler, L J; Karpinski, N C; Terkeltaub, R A

    1999-08-01

    The adult onset metabolic myopathy of carnitine palmitoyl transferase II (CPT II) deficiency is under-recognized, in part due to variable degrees of enzyme deficiency and symptomatology, as well as limitations in means for noninvasive evaluation. We describe a proton magnetic resonance spectroscopy (MRS) technique, using a standard clinical magnetic resonance imaging scanner, to diagnose and help monitor the response to therapy in adult CPT II deficiency. A 53-year-old woman presented with a long standing history of diffuse aching and fatigue provoked by high fat intake, fasting, or prolonged exertion. Muscle biopsy revealed myopathic features and a deficiency (33% of control) of CPT II activity with elevated palmitoyl carnitine. Proton MRS of the soleus muscle was performed using a 1.5 Tesla scanner before and during dietary therapy. Proton MRS revealed shortening of the transverse relaxation time (T2), consistent with increased acetylation of the carnitine pool. The symptoms resolved completely by treatment with frequent feedings of a high carbohydrate diet low in long chain fatty acids supplemented with medium chain triglycerides and L-carnitine. Recovery of normal muscle MRS and carnitine T2 relaxation was documented by the third month of therapy. Proton MRS is a novel, potentially useful, and readily available adjunct in the diagnosis and therapeutic monitoring of muscle CPT II deficiency.

  14. Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Silvia A.; Paladino, Monica G. [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina); Affranchino, Jose L., E-mail: jose.affranchino@comunidad.ub.edu.ar [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina)

    2012-06-20

    The feline immunodeficiency virus (FIV) envelope glycoprotein (Env) possesses a short cytoplasmic domain of 53 amino acids containing four highly conserved cysteines at Env positions 804, 811, 815 and 848. Since palmitoylation of transmembrane proteins occurs at or near the membrane anchor, we investigated whether cysteines 804, 811 and 815 are acylated and analyzed the relevance of these residues for Env functions. Replacement of cysteines 804, 811 and 815 individually or in combination by serine residues resulted in Env glycoproteins that were efficiently expressed and processed. However, mutations C804S and C811S reduced Env fusogenicity by 93% and 84%, respectively, compared with wild-type Env. By contrast, mutant C815S exhibited a fusogenic capacity representing 50% of the wild-type value. Remarkably, the double mutation C804S/C811S abrogated both Env fusion activity and Env incorporation into virions. Finally, by means of Click chemistry assays we demonstrated that the four FIV Env cytoplasmic cysteines are palmitoylated.

  15. Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

    International Nuclear Information System (INIS)

    González, Silvia A.; Paladino, Mónica G.; Affranchino, José L.

    2012-01-01

    The feline immunodeficiency virus (FIV) envelope glycoprotein (Env) possesses a short cytoplasmic domain of 53 amino acids containing four highly conserved cysteines at Env positions 804, 811, 815 and 848. Since palmitoylation of transmembrane proteins occurs at or near the membrane anchor, we investigated whether cysteines 804, 811 and 815 are acylated and analyzed the relevance of these residues for Env functions. Replacement of cysteines 804, 811 and 815 individually or in combination by serine residues resulted in Env glycoproteins that were efficiently expressed and processed. However, mutations C804S and C811S reduced Env fusogenicity by 93% and 84%, respectively, compared with wild-type Env. By contrast, mutant C815S exhibited a fusogenic capacity representing 50% of the wild-type value. Remarkably, the double mutation C804S/C811S abrogated both Env fusion activity and Env incorporation into virions. Finally, by means of Click chemistry assays we demonstrated that the four FIV Env cytoplasmic cysteines are palmitoylated.

  16. A novel Pseudomonas aeruginosa bacteriophage, Ab31, a chimera formed from temperate phage PAJU2 and P. putida lytic phage AF: characteristics and mechanism of bacterial resistance.

    Directory of Open Access Journals (Sweden)

    Libera Latino

    Full Text Available A novel temperate bacteriophage of Pseudomonas aeruginosa, phage vB_PaeP_Tr60_Ab31 (alias Ab31 is described. Its genome is composed of structural genes related to those of lytic P. putida phage AF, and regulatory genes similar to those of temperate phage PAJU2. The virion structure resembles that of phage AF and other lytic Podoviridae (S. enterica Epsilon 15 and E. coli phiv10 with similar tail spikes. Ab31 was able to infect P. aeruginosa strain PA14 and two genetically related strains called Tr60 and Tr162, out of 35 diverse strains from cystic fibrosis patients. Analysis of resistant host variants revealed different phenotypes, including induction of pigment and alginate overproduction. Whole genome sequencing of resistant variants highlighted the existence of a large deletion of 234 kbp in two strains, encompassing a cluster of genes required for the production of CupA fimbriae. Stable lysogens formed by Ab31 in strain Tr60, permitted the identification of the insertion site. During colonization of the lung in cystic fibrosis patients, P. aeruginosa adapts by modifying its genome. We suggest that bacteriophages such as Ab31 may play an important role in this adaptation by selecting for bacterial characteristics that favor persistence of bacteria in the lung.

  17. Role of defective Oct-2 and OCA-B expression in immunoglobulin production and Kaposi's sarcoma-associated herpesvirus lytic reactivation in primary effusion lymphoma.

    Science.gov (United States)

    Di Bartolo, Daniel L; Hyjek, Elizabeth; Keller, Shannon; Guasparri, Ilaria; Deng, Hongyu; Sun, Ren; Chadburn, Amy; Knowles, Daniel M; Cesarman, Ethel

    2009-05-01

    Primary effusion lymphoma (PEL) is a distinct type of B-cell non-Hodgkin lymphoma characterized by the presence of Kaposi's sarcoma-associated herpesvirus (KSHV/human herpesvirus 8). Despite having a genotype and gene expression signature of highly differentiated B cells, PEL does not usually express surface or cytoplasmic immunoglobulin (Ig). We show the lack of Oct-2 and OCA-B transcription factors to be responsible, at least in part, for this defect in Ig production. Like Ig genes, ORF50, the key regulator of the switch from latency to lytic reactivation, contains an octamer motif within its promoter. We therefore examined the impact of Oct-2 and OCA-B on ORF50 activation. The binding of Oct-1 to the ORF50 promoter has been shown to significantly enhance ORF50 transactivation. We found that Oct-2, on the other hand, inhibited ORF50 expression and consequently lytic reactivation by competing with Oct-1 for the octamer motif in the ORF50 promoter. Our data suggest that Oct-2 downregulation in infected cells would be favorable to KSHV in allowing for efficient viral reactivation.

  18. Bacteriophage Infectivity Against Pseudomonas aeruginosa in Saline Conditions

    KAUST Repository

    Scarascia, Giantommaso; Yap, Scott A.; Kaksonen, Anna H.; Hong, Pei-Ying

    2018-01-01

    at different temperature, pH, and salinity. Bacteriophages showed optimal infectivity at a multiplicity of infection of 10 in saline conditions, and demonstrated lytic abilities over all tested temperature (25, 30, 37, and 45°C) and pH 6–9. Planktonic P

  19. In situ crystallization and transformation kinetics of polymorphic forms of saturated-unsaturated-unsaturated triacylglycerols: 1-palmitoyl-2,3-dioleoyl glycerol, 1-stearoyl-2,3-dioleoyl glycerol, and 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol.

    Science.gov (United States)

    Bayés-García, L; Calvet, T; Cuevas-Diarte, M A; Ueno, S

    2016-07-01

    We examined the influence of dynamic thermal treatment (variation of cooling/heating rates) on the polymorphic crystallization and transformation pathways of 1-palmitoyl-2,3-dioleoyl glycerol (POO), 1-stearoyl-2,3-dioleoyl glycerol (SOO), and 1-palmitoyl-2-oleoyl-3-linoleoyl glycerol (POL), which are major saturated-unsaturated-unsaturated (SUU) triacylglycerols (TAGs) of vegetable oils and animal fats (e.g., palm oil, olive oil, and Iberian ham fat). Using mainly a combination of differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD), we analyzed the polymorphic behavior of TAGs when high (15°Cmin -1 ), intermediate (2°Cmin -1 ), and low (0.5°Cmin -1 ) cooling and heating rates were applied. Multiple polymorphic forms were detected in POO, SOO, and POL (sub-α, α, β' 2 , and β' 1 ). Transient disordered phases, defined as kinetic liquid crystal (KLC) phases, were determined in POO and SOO for the first time. The results demonstrated that more stable forms were directly obtained from the melt by decreasing the cooling rates, whereas less stable forms predominated at high cooling rates, as confirmed in our previous work. Regarding heating rate variation, we confirmed that the nature of the polymorphic transformations observed (solid-state, transformation through KLC phase, or melt-mediation) depended largely on the heating rate. These results were discussed considering the activation energies involved in each process and compared with previous studies on TAGs with different saturated-unsaturated structures (1,3-dioleoyl-2-palmitoylglycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, trioleoyl glycerol, and 1,2-dioleoyl-3-linoleoyl glycerol). Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Infection,

    Science.gov (United States)

    1980-10-16

    characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection

  1. pUL34 binding near the human cytomegalovirus origin of lytic replication enhances DNA replication and viral growth.

    Science.gov (United States)

    Slayton, Mark; Hossain, Tanvir; Biegalke, Bonita J

    2018-05-01

    The human cytomegalovirus (HCMV) UL34 gene encodes sequence-specific DNA-binding proteins (pUL34) which are required for viral replication. Interactions of pUL34 with DNA binding sites represses transcription of two viral immune evasion genes, US3 and US9. 12 additional predicted pUL34-binding sites are present in the HCMV genome (strain AD169) with three binding sites concentrated near the HCMV origin of lytic replication (oriLyt). We used ChIP-seq analysis of pUL34-DNA interactions to confirm that pUL34 binds to the oriLyt region during infection. Mutagenesis of the UL34-binding sites in an oriLyt-containing plasmid significantly reduced viral-mediated oriLyt-dependent DNA replication. Mutagenesis of these sites in the HCMV genome reduced the replication efficiencies of the resulting viruses. Protein-protein interaction analyses demonstrated that pUL34 interacts with the viral proteins IE2, UL44, and UL84, that are essential for viral DNA replication, suggesting that pUL34-DNA interactions in the oriLyt region are involved in the DNA replication cascade. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. In vitro characterization and in vivo properties of Salmonellae lytic bacteriophages isolated from free-range layers

    Directory of Open Access Journals (Sweden)

    L Fiorentin

    2004-06-01

    Full Text Available Occurrence of food poisoning related to Salmonella-contaminated eggs and chicken meat has been frequent in humans. Salmonella Enteritidis (SE and Salmonella Typhimurium (ST are included among the most important paratyphoid salmonellae associated with chicken meat and eggs. Elimination of Salmonella at the pre-harvest stage can play a significant role in preventing the introduction of this pathogen into the food chain and consequently in the reduction of food poisoning in humans. Bactericidal bacteriophages may provide a natural, nontoxic, feasible and non-expensive component of the multi-factorial approach for a pre-harvest control of Salmonella in poultry. Five bacteriophages lytic for SE PT4 and ST were obtained from 107 samples of feces of free-range layers in Brazil. All bacteriophages were characterized in vitro and in vivo, showing head and tail morphology and dsDNA as nucleic acids. Results of "in vivo" studies suggested that bacteriophages do not remain in Salmonella-free birds longer than one day, whereas they multiply in Salmonella-infected birds for longer periods. Besides, selection for phage-resistant SE PT4 did not seem to occur in the short term. Isolated bacteriophages will be investigated for their potential for pre-harvest biocontrol of SE PT4 in poultry.

  3. The role of staphylococci in subclinical mastitis of cows and lytic phage isolation against to Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Aliye Gulmez Saglam

    2017-12-01

    Full Text Available Aim: This study was conducted to determine the role of Staphylococcus in the formation of subclinical mastitis in cows and to isolate the phage against isolated Staphylococcus aureus strains. Materials and Methods: In this study, 400 milk cows were screened by California Mastitis Test (CMT for subclinical mastitis and 235 udders of 96 cows, which were determined to be positive, were evaluated for Staphylococcus. Milk samples were evaluated using conventional and molecular methods. In addition, phage isolation studies were performed against S. aureus strains causing mastitis. Results: At the result of cultural examination, of 235 milk samples that were found as positive for mastitis by CMT, a total of 117 (49.7% Staphylococcus spp. were isolated as a distribution of 74 (63.24% coagulase-positive staphylococci and 43 (36.75% coagulase-negative staphylococci. Of these isolates, 76 (64.95% were characterized as S. aureus both conventional and molecular techniques. Lytic bacteriophages against two S. aureus strains which were isolated from mastitic milk samples were obtained from wastewater samples. Conclusion: The results of this study show that a significant portion of subclinical mastitis was formed by staphylococci. In addition, phage isolation against S. aureus strains isolated can be considered as one of the steps to be applied in the prophylaxis and treatment of such infections.

  4. Intracellular APP Domain Regulates Serine-Palmitoyl-CoA Transferase Expression and Is Affected in Alzheimer's Disease

    Science.gov (United States)

    Grimm, Marcus O. W.; Grösgen, Sven; Rothhaar, Tatjana L.; Burg, Verena K.; Hundsdörfer, Benjamin; Haupenthal, Viola J.; Friess, Petra; Müller, Ulrike; Fassbender, Klaus; Riemenschneider, Matthias; Grimm, Heike S.; Hartmann, Tobias

    2011-01-01

    Lipids play an important role as risk or protective factors in Alzheimer's disease (AD), a disease biochemically characterized by the accumulation of amyloid beta peptides (Aβ), released by proteolytic processing of the amyloid precursor protein (APP). Changes in sphingolipid metabolism have been associated to the development of AD. The key enzyme in sphingolipid de novo synthesis is serine-palmitoyl-CoA transferase (SPT). In the present study we identified a new physiological function of APP in sphingolipid synthesis. The APP intracellular domain (AICD) was found to decrease the expression of the SPT subunit SPTLC2, the catalytic subunit of the SPT heterodimer, resulting in that decreased SPT activity. AICD function was dependent on Fe65 and SPTLC2 levels are increased in APP knock-in mice missing a functional AICD domain. SPTLC2 levels are also increased in familial and sporadic AD postmortem brains, suggesting that SPT is involved in AD pathology. PMID:21660213

  5. Characteristics of a broad lytic spectrum endolysin from phage BtCS33 of Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Yuan Yihui

    2012-12-01

    Full Text Available Abstract Background Endolysins produced by bacteriophages lyse bacteria, and are thus considered a novel type of antimicrobial agent. Several endolysins from Bacillus phages or prophages have previously been characterized and used to target Bacillus strains that cause disease in animals and humans. B. thuringiensis phage BtCS33 is a Siphoviridae family phage and its genome has been sequenced and analyzed. In the BtCS33 genome, orf18 was found to encode an endolysin protein (PlyBt33. Results Bioinformatic analyses showed that endolysin PlyBt33 was composed of two functional domains, the N-terminal catalytic domain and the C-terminal cell wall binding domain. In this study, the entire endolysin PlyBt33, and both the N- and C-termini,were expressed in Escherichia coli and then purified. The lytic activities of PlyBt33 and its N-terminus were tested on bacteria. Both regions exhibited lytic activity, although PlyBt33 showed a higher lytic activity than the N-terminus. PlyBt33 exhibited activity against all Bacillus strains tested from five different species, but was not active against Gram-negative bacteria. Optimal conditions for PlyBt33 reactivity were pH 9.0 and 50°C. PlyBt33 showed high thermostability, with 40% of initial activity remaining following 1 h of treatment at 60°C. The C-terminus of PlyBt33 bound to B. thuringiensis strain HD-73 and Bacillus subtilis strain 168. This cell wall binding domain might be novel, as its amino acid sequence showed little similarity to previously reported endolysins. Conclusions PlyBt33 showed potential as a novel antimicrobial agent at a relatively high temperature and had a broad lytic spectrum within the Bacillus genus. The C-terminus of PlyBt33 might be a novel kind of cell wall binding domain.

  6. Transfection of mouse cytotoxic T lymphocyte with an antisense granzyme A vector reduces lytic activity.

    Science.gov (United States)

    Talento, A; Nguyen, M; Law, S; Wu, J K; Poe, M; Blake, J T; Patel, M; Wu, T J; Manyak, C L; Silberklang, M

    1992-12-15

    Murine CTL have seven serine proteases, known as granzymes, in their lytic granules. Despite considerable effort, convincing evidence that these enzymes play an obligatory role in the lytic process has not been presented. To investigate the function of one of these proteases, granzyme A (GA), we utilized an antisense expression vector to lower the level of the enzyme in the cells. An expression vector containing antisense cDNA for GA and the gene for hygromycin B resistance was constructed and electroporated into the murine CTL line, AR1. Transfectants were selected based on resistance to hygromycin B, and a number of stable lines were developed. One of the antisense lines had greatly reduced levels of GA mRNA, when compared to the parental cells or to control lines transfected with the vector lacking the antisense DNA. The message levels for two other CTL granule proteins, granzyme B and perforin, were unaffected by the antisense vector. The amount of GA, as measured by enzymatic activity, was 3- to 10-fold lower in the transfectant. Most significantly, this line also consistently showed 50 to 70% lower ability to lyse nucleated target cells and to degrade their DNA. Furthermore, it exhibited 90 to 95% lower lytic activity to anti-CD3-coated SRBC. Conjugate formation with target cells, however, was normal. These data provide strong evidence that GA plays an important role in the cytolytic cycle, and that the quantity of enzyme is a limiting factor in these cytolytic cells.

  7. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's Sarcoma-associated herpesvirus by herpes simplex virus type 1

    Directory of Open Access Journals (Sweden)

    Lv Zhigang

    2011-10-01

    Full Text Available Abstract Background Kaposi's sarcoma-associated herpesvirus (KSHV is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS, primary effusion lymphoma (PEL and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1 was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1/signal transducer and activator of transcription 3 (STAT3 or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K/protein kinase B (PKB, also called AKT pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN and glycogen synthase kinase-3β (GSK-3β. PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK mitogen-activated protein kinase (MAPK pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.

  8. Clinical Manifestations of Kaposi Sarcoma Herpesvirus Lytic Activation: Multicentric Castleman Disease (KSHV-MCD) and the KSHV Inflammatory Cytokine Syndrome.

    Science.gov (United States)

    Polizzotto, Mark N; Uldrick, Thomas S; Hu, Duosha; Yarchoan, Robert

    2012-01-01

    Soon after the discovery of Kaposi sarcoma (KS)-associated herpesvirus (KSHV), it was appreciated that this virus was associated with most cases of multicentric Castleman disease (MCD) arising in patients infected with human immunodeficiency virus. It has subsequently been recognized that KSHV-MCD is a distinct entity from other forms of MCD. Like MCD that is unrelated to KSHV, the clinical presentation of KSHV-MCD is dominated by systemic inflammatory symptoms including fevers, cachexia, and laboratory abnormalities including cytopenias, hypoalbuminemia, hyponatremia, and elevated C-reactive protein. Pathologically KSHV-MCD is characterized by polyclonal, IgM-lambda restricted plasmacytoid cells in the intrafollicular areas of affected lymph nodes. A portion of these cells are infected with KSHV and a sizable subset of these cells express KSHV lytic genes including a viral homolog of interleukin-6 (vIL-6). Patients with KSHV-MCD generally have elevated KSHV viral loads in their peripheral blood. Production of vIL-6 and induction of human (h) IL-6 both contribute to symptoms, perhaps in combination with overproduction of IL-10 and other cytokines. Until recently, the prognosis of patients with KSHV-MCD was poor. Recent therapeutic advances targeting KSHV-infected B cells with the anti-CD20 monoclonal antibody rituximab and utilizing KSHV enzymes to target KSHV-infected cells have substantially improved patient outcomes. Recently another KSHV-associated condition, the KSHV inflammatory cytokine syndrome (KICS) has been described. Its clinical manifestations resemble those of KSHV-MCD but lymphadenopathy is not prominent and the pathologic nodal changes of KSHV-MCD are absent. Patients with KICS exhibit elevated KSHV viral loads and elevation of vIL-6, homolog of human interleukin-6 and IL-10 comparable to those seen in KSHV-MCD; the cellular origin of these is a matter of investigation. KICS may contribute to the inflammatory symptoms seen in some patients with

  9. Clinical Manifestations of Kaposi Sarcoma Herpesvirus Lytic Activation: Multicentric Castleman Disease (KSHV–MCD) and the KSHV Inflammatory Cytokine Syndrome

    Science.gov (United States)

    Polizzotto, Mark N.; Uldrick, Thomas S.; Hu, Duosha; Yarchoan, Robert

    2012-01-01

    Soon after the discovery of Kaposi sarcoma (KS)-associated herpesvirus (KSHV), it was appreciated that this virus was associated with most cases of multicentric Castleman disease (MCD) arising in patients infected with human immunodeficiency virus. It has subsequently been recognized that KSHV–MCD is a distinct entity from other forms of MCD. Like MCD that is unrelated to KSHV, the clinical presentation of KSHV–MCD is dominated by systemic inflammatory symptoms including fevers, cachexia, and laboratory abnormalities including cytopenias, hypoalbuminemia, hyponatremia, and elevated C-reactive protein. Pathologically KSHV–MCD is characterized by polyclonal, IgM-lambda restricted plasmacytoid cells in the intrafollicular areas of affected lymph nodes. A portion of these cells are infected with KSHV and a sizable subset of these cells express KSHV lytic genes including a viral homolog of interleukin-6 (vIL-6). Patients with KSHV–MCD generally have elevated KSHV viral loads in their peripheral blood. Production of vIL-6 and induction of human (h) IL-6 both contribute to symptoms, perhaps in combination with overproduction of IL-10 and other cytokines. Until recently, the prognosis of patients with KSHV–MCD was poor. Recent therapeutic advances targeting KSHV-infected B cells with the anti-CD20 monoclonal antibody rituximab and utilizing KSHV enzymes to target KSHV-infected cells have substantially improved patient outcomes. Recently another KSHV-associated condition, the KSHV inflammatory cytokine syndrome (KICS) has been described. Its clinical manifestations resemble those of KSHV–MCD but lymphadenopathy is not prominent and the pathologic nodal changes of KSHV–MCD are absent. Patients with KICS exhibit elevated KSHV viral loads and elevation of vIL-6, homolog of human interleukin-6 and IL-10 comparable to those seen in KSHV–MCD; the cellular origin of these is a matter of investigation. KICS may contribute to the inflammatory symptoms seen in some

  10. Palmitoylation of the cysteine-rich endodomain of the SARS-coronavirus spike glycoprotein is important for spike-mediated cell fusion

    International Nuclear Information System (INIS)

    Petit, Chad M.; Chouljenko, Vladimir N.; Iyer, Arun; Colgrove, Robin; Farzan, Michael; Knipe, David M.; Kousoulas, K.G.

    2007-01-01

    The SARS-coronavirus (SARS-CoV) is the etiological agent of the severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. The cytoplasmic portion of the S glycoprotein contains four cysteine-rich amino acid clusters. Individual cysteine clusters were altered via cysteine-to-alanine amino acid replacement and the modified S glycoproteins were tested for their transport to cell-surfaces and ability to cause cell fusion in transient transfection assays. Mutagenesis of the cysteine cluster I, located immediately proximal to the predicted transmembrane, domain did not appreciably reduce cell-surface expression, although S-mediated cell fusion was reduced by more than 50% in comparison to the wild-type S. Similarly, mutagenesis of the cysteine cluster II located adjacent to cluster I reduced S-mediated cell fusion by more than 60% compared to the wild-type S, while cell-surface expression was reduced by less than 20%. Mutagenesis of cysteine clusters III and IV did not appreciably affect S cell-surface expression or S-mediated cell fusion. The wild-type S was palmitoylated as evidenced by the efficient incorporation of 3 H-palmitic acid in wild-type S molecules. S glycoprotein palmitoylation was significantly reduced for mutant glycoproteins having cluster I and II cysteine changes, but was largely unaffected for cysteine cluster III and IV mutants. These results show that the S cytoplasmic domain is palmitoylated and that palmitoylation of the membrane proximal cysteine clusters I and II may be important for S-mediated cell fusion

  11. Flux control analysis of mitochondrial oxidative phosphorylation in rat skeletal muscle: pyruvate and palmitoyl-carnitine as substrates give different control patterns

    DEFF Research Database (Denmark)

    Fritzen, Anette J; Grunnet, Niels; Quistorff, Bjørn

    2007-01-01

    was associated with the ADP-generating system, i.e., 0.58 +/- 0.05 with pyruvate, but significantly lower, 0.40 +/- 0.05, with palmitoyl-carnitine as substrate. The flux control coefficients of complex I, III and IV, the ATP synthase, the ATP/ADP carrier and the P(i) carrier were 0.070 +/- 0.03, 0.083 +/- 0.......04, 0.054 +/- 0.01, 0.11 +/- 0.03, 0.090 +/- 0.03 and 0.026 +/- 0.01, respectively, with pyruvate as substrate. With palmitoyl-carnitine all control coefficients were significantly different, except for the P(i) carrier (i.e., 0.024 +/- 0.001, 0.036 +/- 0.01, 0.052 +/- 0.02, 0.020 +/- 0.002, 0.034 +/- 0.......02 and 0.012 +/- 0.002, respectively), probably caused by the shift from NADH to FADH(2) oxidation. The sum of flux control coefficients was not significantly different from unity with pyruvate, while only 0.58 with palmitoyl-carnitine, indicating significant control contributions from the enzymes involved...

  12. PD-1 blocks lytic granule polarization with concomitant impairment of integrin outside-in signaling in the natural killer cell immunological synapse.

    Science.gov (United States)

    Huang, Yu; Chen, Zhiying; Jang, Joon Hee; Baig, Mirza S; Bertolet, Grant; Schroeder, Casey; Huang, Shengjian; Hu, Qian; Zhao, Yong; Lewis, Dorothy E; Qin, Lidong; Zhu, Michael Xi; Liu, Dongfang

    2018-04-18

    The inhibitory receptor programmed cell death protein 1 (PD-1) is upregulated on a variety of immune cells, including natural killer (NK) cells, during chronic viral infection and tumorigenesis. Blockade of PD-1 or its ligands produces durable clinical responses with tolerable side effects in patients with a broad spectrum of cancers. However, the underlying molecular mechanisms of how PD-1 regulates NK cell function remain poorly characterized. We sought to determine the effect of PD-1 signaling on NK cells. PD-1 was overexpressed in CD16-KHYG-1 (a human NK cell line with both antibody-dependent cellular cytotoxicity through CD16 and natural cytotoxicity through NKG2D) cells and stimulated by exposing the cells to NK-sensitive target cells expressing programmed death ligand 1 (PD-L1). PD-1 engagement by PD-L1 specifically blocked NK cell-mediated cytotoxicity without interfering with the conjugation between NK cells and target cells. Further examination showed that PD-1 signaling blocked lytic granule polarization in NK cells, which was accompanied by failure of integrin-linked kinase, a key molecule in the integrin outside-in signaling pathway, to accumulate in the immunological synapse after NK-target cell conjugation. Our results suggest that NK cell cytotoxicity is inhibited by PD-1 engagement, which blocks lytic granule polarization to the NK cell immunological synapse with concomitant impairment of integrin outside-in signaling. This study provides novel mechanistic insights into how PD-1 inhibition disrupts NK cell function. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  13. Radiation-induced focal cortical necrosis of the femur presenting as a lytic lesion

    Energy Technology Data Exchange (ETDEWEB)

    Ilaslan, Hakan; Schils, Jean [Cleveland Clinic, Musculoskeletal Radiology, Cleveland, OH (United States); Joyce, Michael [Cleveland Clinic, Orthopedic Oncology, Cleveland, OH (United States); Shah, Chirag [Cleveland Clinic, Radiation Oncology, Cleveland, OH (United States); Zhang, Yaxia [Cleveland Clinic, Pathology, Cleveland, OH (United States)

    2017-11-15

    Management of soft tissue sarcomas is often complicated, requiring radiation before and in some cases after limb-sparing surgery. Radiation necrosis is a severe complication after radiation treatment and is typically dose related and involves medullary bone. We report on two cases of hitherto unreported focal circumscribed intra-cortical lytic lesions within the radiation portal, which appeared 19 months and 31 months, respectively, after the conclusion of radiation treatment. Both patients had a history of soft tissue sarcoma treated with radiation (66 Gy) and surgical resection. Biopsy of these lesions showed necrotic bone attributed to radiation. (orig.)

  14. Percutaneous aspiration biopsy in cervical spine lytic lesions. Indications and technique

    Energy Technology Data Exchange (ETDEWEB)

    Tampieri, D; Weill, A; Melanson, D; Ethier, R [Montreal Neurological Inst. and Hospital, PQ (Canada). Dept. of Neuroradiology

    1991-02-01

    We describe the technique and the results of the percutaneous aspiration biopsy (PAB) in a series of 9 patients presenting with neck pain and different degrees of myelopathy, in whom the cervical spine X-ray demonstrated lytic lesions of unknown origin. PAB is a useful, relatively safe technique, and leads to histological diagnosis between metastatic and inflammatory processes. Furthermore, in inflammatory lesions with negative hemoculture, PAB may help in detecting the micro-organism responsible and therefore allow a better antibiotic treatment. (orig.).

  15. Palmitoylation-dependent CDKL5–PSD-95 interaction regulates synaptic targeting of CDKL5 and dendritic spine development

    Science.gov (United States)

    Zhu, Yong-Chuan; Li, Dan; Wang, Lu; Lu, Bin; Zheng, Jing; Zhao, Shi-Lin; Zeng, Rong; Xiong, Zhi-Qi

    2013-01-01

    The X-linked gene cyclin-dependent kinase-like 5 (CDKL5) is mutated in severe neurodevelopmental disorders, including some forms of atypical Rett syndrome, but the function and regulation of CDKL5 protein in neurons remain to be elucidated. Here, we show that CDKL5 binds to the scaffolding protein postsynaptic density (PSD)-95, and that this binding promotes the targeting of CDKL5 to excitatory synapses. Interestingly, this binding is not constitutive, but governed by palmitate cycling on PSD-95. Furthermore, pathogenic mutations that truncate the C-terminal tail of CDKL5 diminish its binding to PSD-95 and synaptic accumulation. Importantly, down-regulation of CDKL5 by RNA interference (RNAi) or interference with the CDKL5–PSD-95 interaction inhibits dendritic spine formation and growth. These results demonstrate a critical role of the palmitoylation-dependent CDKL5–PSD-95 interaction in localizing CDKL5 to synapses for normal spine development and suggest that disruption of this interaction by pathogenic mutations may be implicated in the pathogenesis of CDKL5-related disorders. PMID:23671101

  16. Palmitoylation-dependent CDKL5-PSD-95 interaction regulates synaptic targeting of CDKL5 and dendritic spine development.

    Science.gov (United States)

    Zhu, Yong-Chuan; Li, Dan; Wang, Lu; Lu, Bin; Zheng, Jing; Zhao, Shi-Lin; Zeng, Rong; Xiong, Zhi-Qi

    2013-05-28

    The X-linked gene cyclin-dependent kinase-like 5 (CDKL5) is mutated in severe neurodevelopmental disorders, including some forms of atypical Rett syndrome, but the function and regulation of CDKL5 protein in neurons remain to be elucidated. Here, we show that CDKL5 binds to the scaffolding protein postsynaptic density (PSD)-95, and that this binding promotes the targeting of CDKL5 to excitatory synapses. Interestingly, this binding is not constitutive, but governed by palmitate cycling on PSD-95. Furthermore, pathogenic mutations that truncate the C-terminal tail of CDKL5 diminish its binding to PSD-95 and synaptic accumulation. Importantly, down-regulation of CDKL5 by RNA interference (RNAi) or interference with the CDKL5-PSD-95 interaction inhibits dendritic spine formation and growth. These results demonstrate a critical role of the palmitoylation-dependent CDKL5-PSD-95 interaction in localizing CDKL5 to synapses for normal spine development and suggest that disruption of this interaction by pathogenic mutations may be implicated in the pathogenesis of CDKL5-related disorders.

  17. Regulation by carbohydrate and clofibric acid of palmitoyl-CoA chain elongation in the liver of rats.

    Science.gov (United States)

    Kudo, Naomi; Toyama, Tomoaki; Mitsumoto, Atsushi; Kawashima, Yoichi

    2003-05-01

    Regulation of palmitoyl-CoA chain elongation (PCE) and its contribution to oleic acid formation were investigated in rat liver in comparison with stearoyl-CoA desaturase (SCD). Hepatic PCE activity was induced by the administration of 20% wt/vol glucose or fructose in the drinking water of normal rats. In streptozotocin-induced diabetic rats, the activities of both PCE and SCD were suppressed, and fructose, but not glucose, feeding caused an increase in the activities of both enzymes. Treatment of normal rats with clofibric acid in combination with carbohydrate further increased PCE, but not SCD, activity. FA analysis of hepatic lipids revealed that the proportion of oleic acid (18:1 n-9) increased upon administration of carbohydrate or clofibric acid. The treatment of rats with clofibric acid in combination with carbohydrate greatly increased the proportion of 18:1 n-9. A significant correlation was observed between PCE activity and the hepatic proportion of 18:1 n-9 (r2 = 0.874, P 0.05). Taken together, these results suggest that carbohydrate induces PCE as well as SCD activity to increase the hepatic 18:1 content in rat liver, and the increased PCE activity seems to be responsible for the further increase in 18:1 n-9 when carbohydrate is administered in combination with clofibric acid.

  18. Protozoacidal Trojan-Horse: use of a ligand-lytic peptide for selective destruction of symbiotic protozoa within termite guts.

    Science.gov (United States)

    Sethi, Amit; Delatte, Jennifer; Foil, Lane; Husseneder, Claudia

    2014-01-01

    For novel biotechnology-based termite control, we developed a cellulose bait containing freeze-dried genetically engineered yeast which expresses a protozoacidal lytic peptide attached to a protozoa-recognizing ligand. The yeast acts as a 'Trojan-Horse' that kills the cellulose-digesting protozoa in the termite gut, which leads to the death of termites, presumably due to inefficient cellulose digestion. The ligand targets the lytic peptide specifically to protozoa, thereby increasing its protozoacidal efficiency while protecting non-target organisms. After ingestion of the bait, the yeast propagates in the termite's gut and is spread throughout the termite colony via social interactions. This novel paratransgenesis-based strategy could be a good supplement for current termite control using fortified biological control agents in addition to chemical insecticides. Moreover, this ligand-lytic peptide system could be used for drug development to selectively target disease-causing protozoa in humans or other vertebrates.

  19. The Networks of Genes Encoding Palmitoylated Proteins in Axonal and Synaptic Compartments Are Affected in PPT1 Overexpressing Neuronal-Like Cells

    Directory of Open Access Journals (Sweden)

    Francesco Pezzini

    2017-08-01

    Full Text Available CLN1 disease (OMIM #256730 is an early childhood ceroid-lipofuscinosis associated with mutated CLN1, whose product Palmitoyl-Protein Thioesterase 1 (PPT1 is a lysosomal enzyme involved in the removal of palmitate residues from S-acylated proteins. In neurons, PPT1 expression is also linked to synaptic compartments. The aim of this study was to unravel molecular signatures connected to CLN1. We utilized SH-SY5Y neuroblastoma cells overexpressing wild type CLN1 (SH-p.wtCLN1 and five selected CLN1 patients’ mutations. The cellular distribution of wtPPT1 was consistent with regular processing of endogenous protein, partially detected inside Lysosomal Associated Membrane Protein 2 (LAMP2 positive vesicles, while the mutants displayed more diffuse cytoplasmic pattern. Transcriptomic profiling revealed 802 differentially expressed genes (DEGs in SH-p.wtCLN1 (as compared to empty-vector transfected cells, whereas the number of DEGs detected in the two mutants (p.L222P and p.M57Nfs*45 was significantly lower. Bioinformatic scrutiny linked DEGs with neurite formation and neuronal transmission. Specifically, neuritogenesis and proliferation of neuronal processes were predicted to be hampered in the wtCLN1 overexpressing cell line, and these findings were corroborated by morphological investigations. Palmitoylation survey identified 113 palmitoylated protein-encoding genes in SH-p.wtCLN1, including 25 ones simultaneously assigned to axonal growth and synaptic compartments. A remarkable decrease in the expression of palmitoylated proteins, functionally related to axonal elongation (GAP43, CRMP1 and NEFM and of the synaptic marker SNAP25, specifically in SH-p.wtCLN1 cells was confirmed by immunoblotting. Subsequent, bioinformatic network survey of DEGs assigned to the synaptic annotations linked 81 DEGs, including 23 ones encoding for palmitoylated proteins. Results obtained in this experimental setting outlined two affected functional modules (connected to

  20. Epstein-Barr virus (EBV Rta-mediated EBV and Kaposi's sarcoma-associated herpesvirus lytic reactivations in 293 cells.

    Directory of Open Access Journals (Sweden)

    Yen-Ju Chen

    Full Text Available Epstein-Barr virus (EBV Rta belongs to a lytic switch gene family that is evolutionarily conserved in all gamma-herpesviruses. Emerging evidence indicates that cell cycle arrest is a common means by which herpesviral immediate-early protein hijacks the host cell to advance the virus's lytic cycle progression. To examine the role of Rta in cell cycle regulation, we recently established a doxycycline (Dox-inducible Rta system in 293 cells. In this cell background, inducible Rta modulated the levels of signature G1 arrest proteins, followed by induction of the cellular senescence marker, SA-β-Gal. To delineate the relationship between Rta-induced cell growth arrest and EBV reactivation, recombinant viral genomes were transferred into Rta-inducible 293 cells. Somewhat unexpectedly, we found that Dox-inducible Rta reactivated both EBV and Kaposi's sarcoma-associated herpesvirus (KSHV, to similar efficacy. As a consequence, the Rta-mediated EBV and KSHV lytic replication systems, designated as EREV8 and ERKV, respectively, were homogenous, robust, and concurrent with cell death likely due to permissive lytic replication. In addition, the expression kinetics of EBV lytic genes in Dox-treated EREV8 cells was similar to that of their KSHV counterparts in Dox-induced ERKV cells, suggesting that a common pathway is used to disrupt viral latency in both cell systems. When the time course was compared, cell cycle arrest was achieved between 6 and 48 h, EBV or KSHV reactivation was initiated abruptly at 48 h, and the cellular senescence marker was not detected until 120 h after Dox treatment. These results lead us to hypothesize that in 293 cells, Rta-induced G1 cell cycle arrest could provide (1 an ideal environment for virus reactivation if EBV or KSHV coexists and (2 a preparatory milieu for cell senescence if no viral genome is available. The latter is hypothetical in a transient-lytic situation.

  1. Bronchogenic adenocarcinoma presenting as a synchronous solitary lytic skull lesion with ischaemic stroke--case report and literature review.

    LENUS (Irish Health Repository)

    O'Connell, David

    2011-01-01

    The authors describe a rare case of metastatic bronchogenic adenocarcinoma in a 55-year-old man presenting with concomittant solitary lytic skull lesion and ischaemic stroke. Metastatic bronchogenic carcinoma is known to present as lytic skull lesions. Primary brain tumours are also known to cause ischaemic brain injury. An underlying stroke risk may be exagerated by cranial tumour surgery. Patients with brain tumours are well known to be predisposed to an increased risk of developing thromboembolic disease. It is unusual to see metastatic bronchogenic adenocarcinoma presenting as ischaemic stroke with a background of concomittant cerebral metastasis. The aetio-pathogenesis of this rare occurrence is discussed with a review of literature.

  2. The use of lytic bacteriophages to reduce E. coli O157:H7 on fresh cut lettuce introduced through cross-contamination

    Science.gov (United States)

    The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield) at 108 PFU/ml or a control (phosphate buffered saline, PBS) was applied to lettuce by either 1) spraying on to lettuce piec...

  3. Augmentation of failed human vertebrae with critical un-contained lytic defect restores their structural competence under functional loading: An experimental study.

    Science.gov (United States)

    Alkalay, Ron N; von Stechow, Dietrich; Hackney, David B

    2015-07-01

    Lytic spinal lesions reduce vertebral strength and may result in their fracture. Vertebral augmentation is employed clinically to provide mechanical stability and pain relief for vertebrae with lytic lesions. However, little is known about its efficacy in strengthening fractured vertebrae containing lytic metastasis. Eighteen unembalmed human lumbar vertebrae, having simulated uncontained lytic defects and tested to failure in a prior study, were augmented using a transpedicular approach and re-tested to failure using a wedge fracture model. Axial and moment based strength and stiffness parameters were used to quantify the effect of augmentation on the structural response of the failed vertebrae. Effects of cement volume, bone mineral density and vertebral geometry on the change in structural response were investigated. Augmentation increased the failed lytic vertebral strength [compression: 85% (Paugmentation is effective in bolstering the failed lytic vertebrae compressive and axial structural competence, showing strength estimates up to 50-90% of historical values of osteoporotic vertebrae without lytic defects. This modest increase suggests that lytic vertebrae undergo a high degree of structural damage at failure, with strength only partially restored by vertebral augmentation. The positive effect of cement volume is self-limiting due to extravasation. Copyright © 2015. Published by Elsevier Ltd.

  4. Regulation of palmitoyl-CoA chain elongation by clofibric acid in the liver of Zucker fa/fa rats.

    Science.gov (United States)

    Toyama, Tomoaki; Kudo, Naomi; Mitsumoto, Atsushi; Kawashima, Yoichi

    2005-05-01

    The regulation of palmitoyl-CoA chain elongation (PCE) by clofibric acid [2-(4-chlorophenoxy)-2-methylpropionic acid] was investigated in comparison with stearoyl-CoA desaturase (SCD) in the liver of obese Zucker fa/fa rats. The proportion of oleic acid in the hepatic lipids of Zucker obese rats is 2.7 times higher than that of lean littermates. The activities of PCE and SCD in the liver of Zucker obese rats were markedly higher than in lean rats, and the hepatic uptake of 2-deoxyglucose (2-DG) was also higher in Zucker obese rats compared with lean rats. The increased activities of SCD and PCE in Zucker obese rats were due to the enhanced expression of mRNA of both SCD1 and rat FA elongase 2 (rELO2), but not SCD2 or rELO1. The proportion of oleic acid in the liver was significantly increased by the administration of clofibric acid to Zucker obese rats, and the hepatic PCE activity and rELO2 mRNA expression, but not the SCD activity or SCD1 mRNA expression, were increased in response to clofibric acid treatment. By contrast, the activities of both PCE and SCD and the mRNA expression of SCD1 and rELO2 in the liver were increased by the treatment of Zucker lean rats with clofibric acid. Multiple regression analysis, which was performed to determine the relationships involving PCE activity, SCD activity, and the proportion of oleic acid, revealed that the three parameters were significantly correlated and that the standardized partial regression coefficient of PCE was higher than that of SCD. These results indicate that oleic acid is synthesized by the concerted action of PCE and SCD and that PCE plays a crucial role in the formation of oleic acid when Zucker fa/fa rats are given clofibric acid.

  5. Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

    Directory of Open Access Journals (Sweden)

    L.C. Carnevali Jr

    2012-08-01

    Full Text Available We examined the capacity of high-intensity intermittent training (HI-IT to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g were randomly distributed into 3 groups: sedentary (Sed, N = 5, HI-IT (N = 10, and moderate-intensity continuous training (MI-CT, N = 10. The trained groups were exercised for 8 weeks with a 10% (HI-IT and a 5% (MI-CT overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01, as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01 and lipoprotein lipase (LPL; P < 0.05. Lactate dehydrogenase also presented a higher maximal activity (nmol·min-1·mg protein-1 in HI-IT (around 83%. We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.

  6. Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

    Energy Technology Data Exchange (ETDEWEB)

    Carnevali, L.C. Jr. [Grupo de Biologia Molecular da Célula, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil); Centro Universitário Ítalo-Brasileiro (Unítalo), São Paulo SP (Brazil); Eder, R.; Lira, F.S. [Grupo de Biologia Molecular da Célula, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil); Lima, W.P. [Grupo de Biologia Molecular da Célula, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil); Instituto Federal de Educação,Ciência e Tecnologia de São Paulo, São Paulo SP (Brazil); Gonçalves, D.C. [Grupo de Biologia Molecular da Célula, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil); Zanchi, N.E. [Laboratorio de Nutrição e Metabolismo Aplicado à Atividade Motora, Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo SP (Brazil); Centro de Pesquisa do Genoma Humano, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil); Nicastro, H. [Laboratorio de Nutrição e Metabolismo Aplicado à Atividade Motora, Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo SP (Brazil); Lavoie, J.M. [Department of Kinesiology, University of Montreal, Montreal (Canada); Seelaender, M.C.L. [Grupo de Biologia Molecular da Célula, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo SP (Brazil)

    2012-06-29

    We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min{sup −1}·mg protein{sup −1}) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a “time-efficient” strategy inducing metabolic adaptation.

  7. Effects of high-intensity intermittent training on carnitine palmitoyl transferase activity in the gastrocnemius muscle of rats

    International Nuclear Information System (INIS)

    Carnevali, L.C. Jr.; Eder, R.; Lira, F.S.; Lima, W.P.; Gonçalves, D.C.; Zanchi, N.E.; Nicastro, H.; Lavoie, J.M.; Seelaender, M.C.L.

    2012-01-01

    We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min −1 ·mg protein −1 ) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a “time-efficient” strategy inducing metabolic adaptation

  8. Probing the structure of glucan lyases – the lytic members of GH31 - by sequence analysis, circular dichroism and proteolysis

    DEFF Research Database (Denmark)

    Ernst, Heidi; Lo Leggio, Leila; Yu, Shukun

    2005-01-01

    Glucan lyase (GL) is a polysaccharide lyase with unique characteristics. It is involved in an alternative pathway for the degradation of alpha-glucans, the anhydrofructose pathway. Sequence similarity suggests that this lytic enzyme belongs to glycoside hydrolase family 31, for which until very r...

  9. Gene Expression of Lytic Endopeptidases AlpA and AlpB from Lysobacter sp. XL1 in Pseudomonads.

    Science.gov (United States)

    Tsfasman, Irina M; Lapteva, Yulia S; Krasovskaya, Ludmila A; Kudryakova, Irina V; Vasilyeva, Natalia V; Granovsky, Igor E; Stepnaya, Olga A

    2015-01-01

    Development of an efficient expression system for (especially secreted) bacterial lytic enzymes is a complicated task due to the specificity of their action. The substrate for such enzymes is peptidoglycan, the main structural component of bacterial cell walls. For this reason, expression of recombinant lytic proteins is often accompanied with lysis of the producing bacterium. This paper presents data on the construction of an inducible system for expression of the lytic peptidases AlpA and AlpB from Lysobacter sp. XL1 in Pseudomonas fluorescens Q2-87, which provides for the successful secretion of these proteins into the culture liquid. In this system, the endopeptidase gene under control of the T7lac promoter was integrated into the bacterial chromosome, as well as the Escherichia coli lactose operon repressor protein gene. The T7 pol gene under lac promoter control, which encodes the phage T7 RNA polymerase, is maintained in Pseudomonas cells on the plasmids. Media and cultivation conditions for the recombinant strains were selected to enable the production of AlpA and AlpB by a simple purification protocol. Production of recombinant lytic enzymes should contribute to the development of new-generation antimicrobial drugs whose application will not be accompanied by selection of resistant microorganisms. © 2015 S. Karger AG, Basel.

  10. Epiphyseal involvement in Erdheim-Chester disease: radiographic and scintigraphic findings in a case with lytic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Hernandez, G.; Tajahuerce-Romera, G.M.; Latorre-Ibanez, M.D.; Lara-Pomares, A. [Servicio de Medicina Nuclear, Hospital Provincial de Castellon (Spain); Vila-Fayos, V. [Servicio de Reumatologia, Hospital Comarcal de Vinaroz (Spain)

    2000-08-01

    We reported a symmetric increase of activity in lower links secondary to Erdheim-Chester disease and demonstrated by bone scans and radiographs. An inusual scintigraphic and radiographic appearance with epiphyseal involvement and lytic lesions is described. Differential diagnosis of bone scan and radiographic findings is discussed. (orig.)

  11. Oxidative cleavage and hydrolytic boosting of cellulose in soybean spent flakes by Trichoderma reesei Cel61A lytic polysaccharide monooxygenase

    DEFF Research Database (Denmark)

    Pierce, Brian; Wittrup Agger, Jane; Wichmann, Jesper

    2017-01-01

    The auxiliary activity family 9 (AA9) copper-dependent lytic polysaccharide monooxygenase (LPMO) from Trichoderma reesei (EG4; TrCel61A) was investigated for its ability to oxidize the complex polysaccharides from soybean. The substrate specificity of the enzyme was assessed against a variety of ...

  12. Needle aspiration biopsy in the diagnosis of lytic bone lesions in histiocytosis X, Ewing's sarcoma and neuroblastoma

    International Nuclear Information System (INIS)

    Thommesen, P.; Frederiksen, P.; Loewhagen, T.; Willems, J.S.

    1978-01-01

    Cytologic smears obtained by needle aspiration biopsy of lytic bone lesions in 15 patients with histiocytosis X, Ewing's sarcoma and neuroblastoma were reviewed. After conventional staining, histiocytosis X could be diagnosed and differentiated from small cell tumours such as Ewing's sarcoma and neuroblastoma. The need for sampling material for cytochemical and ultrastructural analysis of these small cell tumours by needle aspiration is emphasized. (Auth.)

  13. Suppression of injuries caused by a lytic RNA virus (mengovirus) and their uncoupling from viral reproduction by mutual cell/virus disarmament.

    Science.gov (United States)

    Mikitas, Olga V; Ivin, Yuri Y; Golyshev, Sergey A; Povarova, Natalia V; Galkina, Svetlana I; Pletjushkina, Olga Y; Nadezhdina, Elena S; Gmyl, Anatoly P; Agol, Vadim I

    2012-05-01

    Viruses often elicit cell injury (cytopathic effect [CPE]), a major cause of viral diseases. CPE is usually considered to be a prerequisite for and/or consequence of efficient viral growth. Recently, we proposed that viral CPE may largely be due to host defensive and viral antidefensive activities. This study aimed to check the validity of this proposal by using as a model HeLa cells infected with mengovirus (MV). As we showed previously, infection of these cells with wild-type MV resulted in necrosis, whereas a mutant with incapacitated antidefensive ("security") viral leader (L) protein induced apoptosis. Here, we showed that several major morphological and biochemical signs of CPE (e.g., alterations in cellular and nuclear shape, plasma membrane, cytoskeleton, chromatin, and metabolic activity) in cells infected with L(-) mutants in the presence of an apoptosis inhibitor were strongly suppressed or delayed for long after completion of viral reproduction. These facts demonstrate that the efficient reproduction of a lytic virus may not directly require development of at least some pathological alterations normally accompanying infection. They also imply that L protein is involved in the control of many apparently unrelated functions. The results also suggest that the virus-activated program with competing necrotic and apoptotic branches is host encoded, with the choice between apoptosis and necrosis depending on a variety of intrinsic and extrinsic conditions. Implementation of this defensive suicidal program could be uncoupled from the viral reproduction. The possibility of such uncoupling has significant implications for the pathogenesis and treatment of viral diseases.

  14. Cooperation between Epstein-Barr Virus Immune Evasion Proteins Spreads Protection from CD8+ T Cell Recognition across All Three Phases of the Lytic Cycle

    Science.gov (United States)

    Quinn, Laura L.; Zuo, Jianmin; Abbott, Rachel J. M.; Shannon-Lowe, Claire; Tierney, Rosemary J.; Hislop, Andrew D.; Rowe, Martin

    2014-01-01

    CD8+ T cell responses to Epstein-Barr virus (EBV) lytic cycle expressed antigens display a hierarchy of immunodominance, in which responses to epitopes of immediate-early (IE) and some early (E) antigens are more frequently observed than responses to epitopes of late (L) expressed antigens. It has been proposed that this hierarchy, which correlates with the phase-specific efficiency of antigen presentation, may be due to the influence of viral immune-evasion genes. At least three EBV-encoded genes, BNLF2a, BGLF5 and BILF1, have the potential to inhibit processing and presentation of CD8+ T cell epitopes. Here we examined the relative contribution of these genes to modulation of CD8+ T cell recognition of EBV lytic antigens expressed at different phases of the replication cycle in EBV-transformed B-cells (LCLs) which spontaneously reactivate lytic cycle. Selective shRNA-mediated knockdown of BNLF2a expression led to more efficient recognition of immediate-early (IE)- and early (E)-derived epitopes by CD8+ T cells, while knock down of BILF1 increased recognition of epitopes from E and late (L)-expressed antigens. Contrary to what might have been predicted from previous ectopic expression studies in EBV-negative model cell lines, the shRNA-mediated inhibition of BGLF5 expression in LCLs showed only modest, if any, increase in recognition of epitopes expressed in any phase of lytic cycle. These data indicate that whilst BNLF2a interferes with antigen presentation with diminishing efficiency as lytic cycle progresses (IE>E>>L), interference by BILF1 increases with progression through lytic cycle (IEevasion functions are actually relevant in the context of lytic virus replication, and secondly identify lytic-cycle phase-specific effects that provide mechanistic insight into the immunodominance pattern seen for CD8+ T cell responses to EBV lytic antigens. PMID:25144360

  15. Activation and Repression of Epstein-Barr Virus and Kaposi's Sarcoma-Associated Herpesvirus Lytic Cycles by Short- and Medium-Chain Fatty Acids

    Science.gov (United States)

    Gorres, Kelly L.; Daigle, Derek; Mohanram, Sudharshan

    2014-01-01

    ABSTRACT The lytic cycles of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are induced in cell culture by sodium butyrate (NaB), a short-chain fatty acid (SCFA) histone deacetylase (HDAC) inhibitor. Valproic acid (VPA), another SCFA and an HDAC inhibitor, induces the lytic cycle of KSHV but blocks EBV lytic reactivation. To explore the hypothesis that structural differences between NaB and VPA account for their functional effects on the two related viruses, we investigated the capacity of 16 structurally related short- and medium-chain fatty acids to promote or prevent lytic cycle reactivation. SCFAs differentially affected EBV and KSHV reactivation. KSHV was reactivated by all SCFAs that are HDAC inhibitors, including phenylbutyrate. However, several fatty acid HDAC inhibitors, such as isobutyrate and phenylbutyrate, did not reactivate EBV. Reactivation of KSHV lytic transcripts could not be blocked completely by any fatty acid tested. In contrast, several medium-chain fatty acids inhibited lytic activation of EBV. Fatty acids that blocked EBV reactivation were more lipophilic than those that activated EBV. VPA blocked activation of the BZLF1 promoter by NaB but did not block the transcriptional function of ZEBRA. VPA also blocked activation of the DNA damage response that accompanies EBV lytic cycle activation. Properties of SCFAs in addition to their effects on chromatin are likely to explain activation or repression of EBV. We concluded that fatty acids stimulate the two related human gammaherpesviruses to enter the lytic cycle through different pathways. IMPORTANCE Lytic reactivation of EBV and KSHV is needed for persistence of these viruses and plays a role in carcinogenesis. Our direct comparison highlights the mechanistic differences in lytic reactivation between related human oncogenic gammaherpesviruses. Our findings have therapeutic implications, as fatty acids are found in the diet and produced by the human microbiota

  16. DNA Damage Signaling Is Induced in the Absence of Epstein-Barr Virus (EBV) Lytic DNA Replication and in Response to Expression of ZEBRA.

    Science.gov (United States)

    Wang'ondu, Ruth; Teal, Stuart; Park, Richard; Heston, Lee; Delecluse, Henri; Miller, George

    2015-01-01

    Epstein Barr virus (EBV), like other oncogenic viruses, modulates the activity of cellular DNA damage responses (DDR) during its life cycle. Our aim was to characterize the role of early lytic proteins and viral lytic DNA replication in activation of DNA damage signaling during the EBV lytic cycle. Our data challenge the prevalent hypothesis that activation of DDR pathways during the EBV lytic cycle occurs solely in response to large amounts of exogenous double stranded DNA products generated during lytic viral DNA replication. In immunofluorescence or immunoblot assays, DDR activation markers, specifically phosphorylated ATM (pATM), H2AX (γH2AX), or 53BP1 (p53BP1), were induced in the presence or absence of viral DNA amplification or replication compartments during the EBV lytic cycle. In assays with an ATM inhibitor and DNA damaging reagents in Burkitt lymphoma cell lines, γH2AX induction was necessary for optimal expression of early EBV genes, but not sufficient for lytic reactivation. Studies in lytically reactivated EBV-positive cells in which early EBV proteins, BGLF4, BGLF5, or BALF2, were not expressed showed that these proteins were not necessary for DDR activation during the EBV lytic cycle. Expression of ZEBRA, a viral protein that is necessary for EBV entry into the lytic phase, induced pATM foci and γH2AX independent of other EBV gene products. ZEBRA mutants deficient in DNA binding, Z(R183E) and Z(S186E), did not induce foci of pATM. ZEBRA co-localized with HP1β, a heterochromatin associated protein involved in DNA damage signaling. We propose a model of DDR activation during the EBV lytic cycle in which ZEBRA induces ATM kinase phosphorylation, in a DNA binding dependent manner, to modulate gene expression. ATM and H2AX phosphorylation induced prior to EBV replication may be critical for creating a microenvironment of viral and cellular gene expression that enables lytic cycle progression.

  17. Testing protozoacidal activity of ligand-lytic peptides against termite gut protozoa in vitro (protozoa culture) and in vivo (microinjection into termite hindgut).

    Science.gov (United States)

    Husseneder, Claudia; Sethi, Amit; Foil, Lane; Delatte, Jennifer

    2010-12-29

    We are developing a novel approach to subterranean termite control that would lead to reduced reliance on the use of chemical pesticides. Subterranean termites are dependent on protozoa in the hindguts of workers to efficiently digest wood. Lytic peptides have been shown to kill a variety of protozoan parasites (Mutwiri et al. 2000) and also protozoa in the gut of the Formosan subterranean termite, Coptotermes formosanus (Husseneder and Collier 2009). Lytic peptides are part of the nonspecific immune system of eukaryotes, and destroy the membranes of microorganisms (Leuschner and Hansel 2004). Most lytic peptides are not likely to harm higher eukaryotes, because they do not affect the electrically neutral cholesterol-containing cell membranes of higher eukaryotes (Javadpour et al. 1996). Lytic peptide action can be targeted to specific cell types by the addition of a ligand. For example, Hansel et al. (2007) reported that lytic peptides conjugated with cancer cell membrane receptor ligands could be used to destroy breast cancer cells, while lytic peptides alone or conjugated with non-specific peptides were not effective. Lytic peptides also have been conjugated to human hormones that bind to receptors on tumor cells for targeted destruction of prostate and testicular cancer cells (Leuschner and Hansel 2004). In this article we present techniques used to demonstrate the protozoacidal activity of a lytic peptide (Hecate) coupled to a heptapeptide ligand that binds to the surface membrane of protozoa from the gut of the Formosan subterranean termite. These techniques include extirpation of the gut from termite workers, anaerobic culture of gut protozoa (Pseudotrichonympha grassii, Holomastigotoides hartmanni,Spirotrichonympha leidyi), microscopic confirmation that the ligand marked with a fluorescent dye binds to the termite gut protozoa and other free-living protozoa but not to bacteria or gut tissue. We also demonstrate that the same ligand coupled to a lytic

  18. Miscibility, chain packing, and hydration of 1-palmitoyl-2-oleoyl phosphatidylcholine and other lipids in surface phases.

    Science.gov (United States)

    Smaby, J M; Brockman, H L

    1985-11-01

    The miscibility of 1-palmitoyl-2-oleoyl phosphatidylcholine with triolein, 1,2-diolein, 1,3-diolein, 1(3)-monoolein, oleyl alcohol, methyl oleate, oleic acid, and oleyl cyanide (18:1 lipids) was studied at the argon-water interface. The isothermal phase diagrams for the mixtures at 24 degrees were characterized by two compositional regions. At the limit of miscibility with lower mol fractions of 18:1 lipid, the surface pressure was composition-independent, but above a mixture-specific stoichiometry, surface pressure at the limit of miscibility was composition-dependent. From the two-dimensional phase rule, it was determined that at low mol fractions of 18:1 lipids, the surface consisted of phospholipid and a preferred packing array or complex of phospholipid and 18:1 lipid, whereas, above the stoichiometry of the complex, the surface phase consisted of complex and excess 18:1 lipids. In both regions of the phase diagram, mixing along the phase boundary was apparently ideal allowing application of an equation of state described earlier (J. M. Smaby and H. L. Brockman, 1984, Biochemistry, 23:3312-3316). From such analysis, apparent partial molecular areas and hydrations for phospholipid, complex, and 18:1 lipid were obtained. Comparison of these calculated parameters for the complexed and uncomplexed states shows that the aliphatic moieties behave independently of polar head group. The transition of each 18:1 chain to the complexed state involves the loss of about one interfacial water molecule and its corresponding area. For 18:1 lipids with more than one chain another two water molecules per additional chain are present in both states but contribute little to molecular area. In contrast to 18:1 lipids, the phospholipid area and hydration change little upon complexation. The uniformity of chain packing and hydration behavior among 18:1 lipid species contrasts with complex stoichiometries that vary from 0.04 to 0.65. This suggests that the stoichiometry of the

  19. In a model of Batten disease, palmitoyl protein thioesterase-1 deficiency is associated with brown adipose tissue and thermoregulation abnormalities.

    Directory of Open Access Journals (Sweden)

    Alfia Khaibullina

    Full Text Available Infantile neuronal ceroid lipofuscinosis (INCL is a fatal neurodegenerative disorder caused by a deficiency of palmitoyl-protein thioesterase-1 (PPT1. We have previously shown that children with INCL have increased risk of hypothermia during anesthesia and that PPT1-deficiency in mice is associated with disruption of adaptive energy metabolism, downregulation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α, and mitochondrial dysfunction. Here we hypothesized that Ppt1-knockout mice, a well-studied model of INCL that shows many of the neurologic manifestations of the disease, would recapitulate the thermoregulation impairment observed in children with INCL. We also hypothesized that when exposed to cold, Ppt1-knockout mice would be unable to maintain body temperature as in mice thermogenesis requires upregulation of Pgc-1α and uncoupling protein 1 (Ucp-1 in brown adipose tissue. We found that the Ppt1-KO mice had lower basal body temperature as they aged and developed hypothermia during cold exposure. Surprisingly, this inability to maintain body temperature during cold exposure in Ppt1-KO mice was associated with an adequate upregulation of Pgc-1α and Ucp-1 but with lower levels of sympathetic neurotransmitters in brown adipose tissue. In addition, during baseline conditions, brown adipose tissue of Ppt1-KO mice had less vacuolization (lipid droplets compared to wild-type animals. After cold stress, wild-type animals had significant decreases whereas Ppt1-KO had insignificant changes in lipid droplets compared with baseline measurements, thus suggesting that Ppt1-KO had less lipolysis in response to cold stress. These results uncover a previously unknown phenotype associated with PPT1 deficiency, that of altered thermoregulation, which is associated with impaired lipolysis and neurotransmitter release to brown adipose tissue during cold exposure. These findings suggest that INCL should be added to the list of

  20. Isolation and characterization of φkm18p, a novel lytic phage with therapeutic potential against extensively drug resistant Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Gwan-Han Shen

    Full Text Available AIMS: To isolate phages against extensively drug resistant Acinetobacter baumannii (XDRAB and characterize the highest lytic capability phage as a model to evaluate the potential on phage therapy. METHODS AND RESULTS: Eight phages were isolated from hospital sewage and showed narrow host spectrum. Phage φkm18p was able to effectively lyse the most XDRAB. It has a dsDNA genome of 45 kb in size and hexagonal head of about 59 nm in diameter and no tail. Bacterial population decreased quickly from 10(8 CFU ml(-1 to 10(3 CFU ml(-1 in 30 min by φkm18p. The 185 kDa lysis protein encoded by φkm18p genome was detected when the extracted protein did not boil before SDS-PAGE; it showed that the lysis protein is a complex rather than a monomer. Phage φkm18p improved human lung epithelial cells survival rates when they were incubated with A. baumannii. Combination of phages (φkm18p, φTZ1 and φ314 as a cocktail could lyse all genotype-varying XDRAB isolates. CONCLUSION: Infections with XDRAB are extremely difficult to treat and development of a phage cocktails therapy could be a therapeutic alternative in the future. Phage φkm18p is a good candidate for inclusion in phage cocktails.

  1. A rapid quantitative activity assay shows that the Vibrio cholerae colonization factor GbpA is an active lytic polysaccharide monooxygenase

    NARCIS (Netherlands)

    Loose, Jennifer S. M.; Forsberg, Zarah; Fraaije, Marco W.; Eijsink, Vincent G. H.; Vaaje-Kolstad, Gustav

    2014-01-01

    The discovery of the copper-dependent lytic polysaccharide monooxygenases (LPMOs) has revealed new territory for chemical and biochemical analysis. These unique mononuclear copper enzymes are abundant, suggesting functional diversity beyond their established roles in the depolymerization of biomass

  2. Unliganded and substrate bound structures of the cellooligosaccharide active lytic polysaccharide monooxygenase LsAA9A at low pH

    DEFF Research Database (Denmark)

    Frandsen, Kristian Erik Høpfner; Poulsen, Jens-Christian Navarro; Tandrup, Tobias

    2017-01-01

    Lytic polysaccharide monooxygenases (LPMOs) have been found to be key components in microbial (bacterial and fungal) degradation of biomass. They are copper metalloenzymes that degrade polysaccharides oxidatively and act in synergy with glycoside hydrolases. Recently crystallographic studies...

  3. A comparative study on the activity of fungal lytic polysaccharide monooxygenases for the depolymerization of cellulose in soybean spent flakes

    DEFF Research Database (Denmark)

    Pierce, Brian; Wittrup Agger, Jane; Zhang, Zhenghong

    2017-01-01

    Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes capable of the oxidative breakdown of polysaccharides. They are of industrial interest due to their ability to enhance the enzymatic depolymerization of recalcitrant substrates by glycoside hydrolases. In this paper, twenty......-four lytic polysaccharide monooxygenases (LPMOs) expressed in Trichoderma reesei were evaluated for their ability to oxidize the complex polysaccharides in soybean spent flakes, an abundant and industrially relevant substrate. TrCel61A, a soy-polysaccharide-active AA9 LPMO from T. reesei, was used...... as a benchmark in this evaluation. In total, seven LPMOs demonstrated activity on pretreated soy spent flakes, with the products from enzymatic treatments evaluated using mass spectrometry and high performance anion exchange chromatography. The hydrolytic boosting effect of the top-performing enzymes...

  4. Lytic bacteriophages reduce Escherichia coli O157: H7 on fresh cut lettuce introduced through cross-contamination.

    Science.gov (United States)

    Ferguson, Sean; Roberts, Cheryl; Handy, Eric; Sharma, Manan

    2013-01-01

    The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield™) or a control (phosphate buffered saline, PBS) was applied to lettuce by either; (1) immersion of lettuce in 500 ml of EcoShield™ 8.3 log PFU/ml or 9.8 log PFU/ml for up to 2 min before inoculation with E. coli O157:H7; (2) spray-application of EcoShield™ (9.3 log PFU/ml) to lettuce after inoculation with E. coli O157:H7 (4.10 CFU/cm 2 ) following exposure to 50 μg/ml chlorine for 30 sec. After immersion studies, lettuce was spot-inoculated with E. coli O157:H7 (2.38 CFU/cm 2 ). Phage-treated, inoculated lettuce pieces were stored at 4°C for and analyzed for E. coli O157:H7 populations for up to 7 d. Immersion of lettuce in 9.8 log PFU/ml EcoShield™ for 2 min significantly (p PFU/ml) resulted in the deposition of high concentrations (7.8 log log PFU/cm 2 ) of bacteriophages on the surface of fresh cut lettuce, potentially contributing to the efficacy of the lytic phages on lettuce. Spraying phages on to inoculated fresh cut lettuce after being washed in hypochlorite solution was significantly more effective in reducing E. coli O157:H7 populations (2.22 log CFU/cm 2 ) on day 0 compared with control treatments (4.10 log CFU/cm 2 ). Both immersion and spray treatments provided protection from E. coli O157:H7 contamination on lettuce, but spray application of lytic bacteriophages to lettuce was more effective in immediately reducing E. coli O157:H7 populations fresh cut lettuce.

  5. AtlA Functions as a Peptidoglycan Lytic Transglycosylase in the Neisseria gonorrhoeae Type IV Secretion System▿

    OpenAIRE

    Kohler, Petra L.; Hamilton, Holly L.; Cloud-Hansen, Karen; Dillard, Joseph P.

    2007-01-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We chara...

  6. Primary intraosseous atypical inflammatory meningioma presenting as a lytic skull lesion: Case report with review of literature.

    Science.gov (United States)

    Bohara, Sangita; Agarwal, Swapnil; Khurana, Nita; Pandey, P N

    2016-01-01

    Primary extradural meningiomas of the skull comprise 1% of all meningiomas, and lytic skull meningiomas are still rarer and are said to be more aggressive. We present a case of 38-year-old male with an extradural tumor which on histopathological examination showed features of inflammatory atypical meningioma (WHO Grade II). The intense inflammatory nature of osteolytic primary intraosseous meningioma has not been reported before. This entity deserves special mention because of the need for adjuvant therapy and proper follow-up.

  7. Human Cytotoxic T Lymphocytes Form Dysfunctional Immune Synapses with B Cells Characterized by Non-Polarized Lytic Granule Release

    Directory of Open Access Journals (Sweden)

    Anna Kabanova

    2016-04-01

    Full Text Available Suppression of the cytotoxic T cell (CTL immune response has been proposed as one mechanism for immune evasion in cancer. In this study, we have explored the underlying basis for CTL suppression in the context of B cell malignancies. We document that human B cells have an intrinsic ability to resist killing by freshly isolated cytotoxic T cells (CTLs, but are susceptible to lysis by IL-2 activated CTL blasts and CTLs isolated from immunotherapy-treated patients with chronic lymphocytic leukemia (CLL. Impaired killing was associated with the formation of dysfunctional non-lytic immune synapses characterized by the presence of defective linker for activation of T cells (LAT signaling and non-polarized release of the lytic granules transported by ADP-ribosylation factor-like protein 8 (Arl8. We propose that non-lytic degranulation of CTLs are a key regulatory mechanism of evasion through which B cells may interfere with the formation of functional immune synapses by CTLs.

  8. Crystal Structures of the SpoIID Lytic Transglycosylases Essential for Bacterial Sporulation.

    Science.gov (United States)

    Nocadello, Salvatore; Minasov, George; Shuvalova, Ludmilla S; Dubrovska, Ievgeniia; Sabini, Elisabetta; Anderson, Wayne F

    2016-07-15

    Bacterial spores are the most resistant form of life known on Earth and represent a serious problem for (i) bioterrorism attack, (ii) horizontal transmission of microbial pathogens in the community, and (iii) persistence in patients and in a nosocomial environment. Stage II sporulation protein D (SpoIID) is a lytic transglycosylase (LT) essential for sporulation. The LT superfamily is a potential drug target because it is active in essential bacterial processes involving the peptidoglycan, which is unique to bacteria. However, the absence of structural information for the sporulation-specific LT enzymes has hindered mechanistic understanding of SpoIID. Here, we report the first crystal structures with and without ligands of the SpoIID family from two community relevant spore-forming pathogens, Bacillus anthracis and Clostridium difficile. The structures allow us to visualize the overall architecture, characterize the substrate recognition model, identify critical residues, and provide the structural basis for catalysis by this new family of enzymes. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Lytic phages obscure the cost of antibiotic resistance in Escherichia coli.

    Science.gov (United States)

    Tazzyman, Samuel J; Hall, Alex R

    2015-03-17

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under phage parasitism, the likelihood that antibiotic-resistant genetic backgrounds spread depends on their initial frequency, mutation rate and intrinsic growth rate relative to drug-susceptible genotypes, because these parameters determine relative rates of phage-resistance evolution on different genetic backgrounds. Moreover, the average cost of antibiotic resistance in terms of intrinsic growth in the antibiotic-free experimental environment was small relative to the benefits of an increased mutation rate in the presence of phages. This is consistent with our theoretical work indicating that, under phage selection, typical costs of antibiotic resistance can be outweighed by realistic increases in mutability if drug resistance and hypermutability are genetically linked, as is frequently observed in clinical isolates. This suggests the long-term distribution of antibiotic resistance depends on the relative rates at which different lineages adapt to other types of selection, which in the case of phage parasitism is probably extremely common, as well as costs of resistance inferred by classical in vitro methods.

  10. Innate Lymphoid Cells (ILCs) as Mediators of Inflammation, Release of Cytokines and Lytic Molecules.

    Science.gov (United States)

    Elemam, Noha Mousaad; Hannawi, Suad; Maghazachi, Azzam A

    2017-12-10

    Innate lymphoid cells (ILCs) are an emerging group of immune cells that provide the first line of defense against various pathogens as well as contributing to tissue repair and inflammation. ILCs have been classically divided into three subgroups based on their cytokine secretion and transcription factor profiles. ILC nomenclature is analogous to that of T helper cells. Group 1 ILCs composed of natural killer (NK) cells as well as IFN-γ secreting ILC1s. ILC2s have the capability to produce T H 2 cytokines while ILC3s and lymphoid tissue inducer (LTis) are subsets of cells that are able to secrete IL-17 and/or IL-22. A recent subset of ILC known as ILC4 was discovered, and the cells of this subset were designated as NK17/NK1 due to their release of IL-17 and IFN-γ. In this review, we sought to explain the subclasses of ILCs and their roles as mediators of lytic enzymes and inflammation.

  11. Innate Lymphoid Cells (ILCs as Mediators of Inflammation, Release of Cytokines and Lytic Molecules

    Directory of Open Access Journals (Sweden)

    Noha Mousaad Elemam

    2017-12-01

    Full Text Available Innate lymphoid cells (ILCs are an emerging group of immune cells that provide the first line of defense against various pathogens as well as contributing to tissue repair and inflammation. ILCs have been classically divided into three subgroups based on their cytokine secretion and transcription factor profiles. ILC nomenclature is analogous to that of T helper cells. Group 1 ILCs composed of natural killer (NK cells as well as IFN-γ secreting ILC1s. ILC2s have the capability to produce TH2 cytokines while ILC3s and lymphoid tissue inducer (LTis are subsets of cells that are able to secrete IL-17 and/or IL-22. A recent subset of ILC known as ILC4 was discovered, and the cells of this subset were designated as NK17/NK1 due to their release of IL-17 and IFN-γ. In this review, we sought to explain the subclasses of ILCs and their roles as mediators of lytic enzymes and inflammation.

  12. Tiam1-Rac1 Axis Promotes Activation of p38 MAP Kinase in the Development of Diabetic Retinopathy: Evidence for a Requisite Role for Protein Palmitoylation

    Directory of Open Access Journals (Sweden)

    Rajakrishnan Veluthakal

    2015-04-01

    Full Text Available Background/Aims: Evidence in multiple tissues, including retina, suggests generation of reactive oxygen species (ROS and the ensuing oxidative stress as triggers for mitochondrial defects and cell apoptosis. We recently reported novel roles for Tiam1-Rac1-Nox2 axis in retinal mitochondrial dysfunction and cell death leading to the development of diabetic retinopathy. Herein, we tested the hypothesis that activation of p38 MAP kinase, a stress kinase, represents the downstream signaling event to Rac1-Nox2 activation in diabetes-induced metabolic stress leading to capillary cell apoptosis. Methods: Activation of p38 MAP kinase was quantified by Western blotting in retinal endothelial cells incubated with high glucose (20 mM for up to 96 hours, a duration where mitochondrial dysfunction and capillary cell apoptosis can be observed. NSC23766 and 2-bromopalmitate (2-BP were used to assess the roles of Tiam1-Rac1 and palmitoylation pathways, respectively. Results: Activation of p38 MAP kinase was observed as early as 3 hours after high glucose exposure, and continued until 96 hours. Consistent with this, p38 MAP kinase activation was significantly higher in the retina from diabetic mice compared to age-matched normal mice. NSC23766 markedly attenuated hyperglycemia-induced activation of p38 MAP kinase. Lastly, 2-BP inhibited glucose-induced Rac1, Nox2 and p38 MAP kinase activation in endothelial cells. Conclusions: Tiam1-Rac1-mediated activation of Nox2 and p38 MAP kinase constitutes early signaling events leading to mitochondrial dysfunction and the development of diabetic retinopathy. Our findings also provide the first evidence to implicate novel roles for protein palmitoylation in this signaling cascade.

  13. Instrumental evaluation of anti-aging effects of cosmetic formulations containing palmitoyl peptides, Silybum marianum seed oil, vitamin E and other functional ingredients on aged human skin.

    Science.gov (United States)

    Hahn, Hyung Jin; Jung, Ho Jung; Schrammek-Drusios, Med Christine; Lee, Sung Nae; Kim, Ji-Hyun; Kwon, Seung Bin; An, In-Sook; An, Sungkwan; Ahn, Kyu Joong

    2016-08-01

    Anti-aging cosmetics are widely used for improving signs of aged skin such as skin wrinkles, decreased elasticity, low dermal density and yellow skin tone. The present study evaluated the effects of cosmetic formulations, eye cream and facial cream, containing palmitoyl peptides, Silybum marianum ( S. marianum ) seed oil, vitamin E and other functional ingredients on the improvement of facial wrinkles, elasticity, dermal density and skin tone after 4 weeks period of application on aged human skin. Healthy volunteers (n=20) with aged skin were recruited to apply the test materials facially twice per day for 4 weeks. Skin wrinkles, elasticity, dermal density and skin tone were measured instrumentally for assessing the improvement of skin aging. All the measurements were conducted prior to the application of test materials and at 2 and 4 weeks of treatment. Crow's feet wrinkles were decreased 5.97% after 2 weeks of test material application and 14.07% after 4 weeks of application in comparison of pre-application. Skin elasticity was increased 6.81% after 2 weeks and 8.79% after 4 weeks. Dermal density was increased 16.74% after 2 weeks and 27.63% after 4 weeks. With the L* value indicating skin brightness and the a* value indicating erythema (redness), the results showed that brightness was increased 1.70% after 2 weeks and 2.14% after 4 weeks, and erythema was decreased 10.45% after 2 weeks and 22.39% after 4 weeks. Hence, the test materials appear to exert some degree of anti-aging effects on aged human skin. There were no abnormal skin responses from the participants during the trial period. We conclude that the facial and eye cream containing palmitoyl peptides and S. marianum seed oil, vitamin E and other ingredients have effects on the improvement of facial wrinkles, elasticity, dermal density and skin tone.

  14. Anti-Inflammatory Effect of 3-O-[(6'-O-Palmitoyl-β-D-glucopyranosyl Sitosterol] from Agave angustifolia on Ear Edema in Mice

    Directory of Open Access Journals (Sweden)

    Elizabeth Hernández-Valle

    2014-09-01

    Full Text Available In Mexico Agave angustifolia has traditionally been used to treat inflammation. The aim of this study was to measure the anti-inflammatory effect of the extract of A. angustifolia, the isolation and identification of active compounds. From the acetone extract two active fractions were obtained, (AsF13 and AaF16. For the characterization of pharmacological activity, the acute inflammatory model of mouse ear edema induced with TPA was used. The tissue exposed to TPA and treatments were subjected to two analysis, cytokine quantification (IL-1β, IL-6, IL-10 and TNF-α and histopathological evaluation. The active fraction (AaF16 consisted principally of 3-O-[(6'-O-palmitoyl-β-D-glucopyranpsyl] sitosterol. In AaF13 fraction was identified β-sitosteryl glucoside (2 and stigmasterol (3. The three treatments tested showed a concentration-dependent anti-inflammatory effect (AaAc Emax = 33.10%, EC50 = 0.126 mg/ear; AaF13 Emax = 54.22%, EC50 = 0.0524 mg/ear; AaF16 Emax = 61.01%, EC50 = 0.050 mg/ear. The application of TPA caused a significant increase on level of IL-1β, IL-6 and TNFα compared with basal condition, which was countered by any of the experimental treatments. Moreover, the experimental treatments induced a significant increase in the levels of IL-4 and IL-10, compared to the level observed when stimulated with TPA. Therefore, the anti-inflammatory effect of Agave angustifolia, is associated with the presence of 3-O-[(6'-O-palmitoyl-β-D-glucopyranosyl] sitosterol.

  15. Mitigating crystallization of saturated FAMES (fatty acid methyl esters) in biodiesel: 4. The phase behavior of 1,3-dioleoyl-2-palmitoyl glycerol – Methyl stearate binary system

    International Nuclear Information System (INIS)

    Mohanan, Athira; Bouzidi, Laziz; Narine, Suresh S.

    2016-01-01

    The present study examines the phase behavior of a model binary system made of OPO (1,3-dioleoyl-2-palmitoyl glycerol); a TAG (triacylglycerol) highly effective in depressing onset of crystallization of biodiesel, and MeS (methyl stearate); a prevalent saturated FAMEs (fatty acid methyl esters) in biodiesel. The thermal behavior, crystal structure and microstructure of the OPO/MeS mixtures were investigated with DSC (differential scanning calorimetry), XRD (X-ray diffraction) and PLM (polarized light microscope). The OPO/MeS system presented a phase diagram with peritectic and eutectic transitions. A simple thermodynamic modeling of the liquidus line indicated a relatively complex mixing behavior, and highlighted the prevailing effect of the peritectic compound on solubility. Different types of microstructures that were more or less influenced by MeS, OPO or/and compound microstructures were observed in the mixtures. They are associated with the crystal phases and the thermal transitions. Furthermore, MeS, OPO and compound crystal structures (monoclinic, orthorhombic and triclinic, respectively) served as templates for the crystal forms of the coexisting phases. The singularities in the liquidus line are attributed to chain length mismatch between the palmitic acid and the FAME (fatty acid methyl ester). The phase diagram achieved for OPO/MeS system is complete and can help in designing additive formulations to improve the cold flow behavior of biodiesel. - Highlights: • 1,3-dioleoyl-2-palmitoyl glycerol/methyl stearate (OPO/MeS) studied in detail. • Phase diagram with thermal transitions, polymorphism, microstructure achieved. • Phase trajectory singularities attributed to length mismatch of linear chains. • Mechanism for disruption of crystallization of biodiesel evidenced and explained.

  16. Small lytic peptides escape the inhibitory effect of heparan sulfate on the surface of cancer cells

    Science.gov (United States)

    2011-01-01

    Background Several naturally occurring cationic antimicrobial peptides (CAPs), including bovine lactoferricin (LfcinB), display promising anticancer activities. These peptides are unaffected by multidrug resistance mechanisms and have been shown to induce a protective immune response against solid tumors, thus making them interesting candidates for developing novel lead structures for anticancer treatment. Recently, we showed that the anticancer activity by LfcinB was inhibited by the presence of heparan sulfate (HS) on the surface of tumor cells. Based on extensive structure-activity relationship studies performed on LfcinB, shorter and more potent peptides have been constructed. In the present study, we have investigated the anticancer activity of three chemically modified 9-mer peptides and the influence of HS and chondroitin sulfate (CS) on their cytotoxic activity. Methods Various cell lines and red blood cells were used to investigate the anticancer activity and selectivity of the peptides. The cytotoxic effect of the peptides against the different cell lines was measured by use of a colorimetric MTT viability assay. The influence of HS and CS on their cytotoxic activity was evaluated by using HS/CS expressing and HS/CS deficient cell lines. The ability of soluble HS and CS to inhibit the cytotoxic activity of the peptides and the peptides' affinity for HS and CS were also investigated. Results The 9-mer peptides displayed selective anticancer activity. Cells expressing HS/CS were equally or more susceptible to the peptides than cells not expressing HS/CS. The peptides displayed a higher affinity for HS compared to CS, and exogenously added HS inhibited the cytotoxic effect of the peptides. Conclusions In contrast to the previously reported inhibitory effect of HS on LfcinB, the present study shows that the cytotoxic activity of small lytic peptides was increased or not affected by cell surface HS. PMID:21453492

  17. Using lytic bacteriophages to eliminate or significantly reduce contamination of food by foodborne bacterial pathogens.

    Science.gov (United States)

    Sulakvelidze, Alexander

    2013-10-01

    Bacteriophages (also called 'phages') are viruses that kill bacteria. They are arguably the oldest (3 billion years old, by some estimates) and most ubiquitous (total number estimated to be 10(30) -10(32) ) known organisms on Earth. Phages play a key role in maintaining microbial balance in every ecosystem where bacteria exist, and they are part of the normal microflora of all fresh, unprocessed foods. Interest in various practical applications of bacteriophages has been gaining momentum recently, with perhaps the most attention focused on using them to improve food safety. That approach, called 'phage biocontrol', typically includes three main types of applications: (i) using phages to treat domesticated livestock in order to reduce their intestinal colonization with, and shedding of, specific bacterial pathogens; (ii) treatments for decontaminating inanimate surfaces in food-processing facilities and other food establishments, so that foods processed on those surfaces are not cross-contaminated with the targeted pathogens; and (iii) post-harvest treatments involving direct applications of phages onto the harvested foods. This mini-review primarily focuses on the last type of intervention, which has been gaining the most momentum recently. Indeed, the results of recent studies dealing with improving food safety, and several recent regulatory approvals of various commercial phage preparations developed for post-harvest food safety applications, strongly support the idea that lytic phages may provide a safe, environmentally-friendly, and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens. However, some important technical and nontechnical problems may need to be addressed before phage biocontrol protocols can become an integral part of routine food safety intervention strategies implemented by food industries in the USA. © 2013 Society of Chemical Industry.

  18. Small lytic peptides escape the inhibitory effect of heparan sulfate on the surface of cancer cells

    Directory of Open Access Journals (Sweden)

    Lindin Inger

    2011-03-01

    Full Text Available Abstract Background Several naturally occurring cationic antimicrobial peptides (CAPs, including bovine lactoferricin (LfcinB, display promising anticancer activities. These peptides are unaffected by multidrug resistance mechanisms and have been shown to induce a protective immune response against solid tumors, thus making them interesting candidates for developing novel lead structures for anticancer treatment. Recently, we showed that the anticancer activity by LfcinB was inhibited by the presence of heparan sulfate (HS on the surface of tumor cells. Based on extensive structure-activity relationship studies performed on LfcinB, shorter and more potent peptides have been constructed. In the present study, we have investigated the anticancer activity of three chemically modified 9-mer peptides and the influence of HS and chondroitin sulfate (CS on their cytotoxic activity. Methods Various cell lines and red blood cells were used to investigate the anticancer activity and selectivity of the peptides. The cytotoxic effect of the peptides against the different cell lines was measured by use of a colorimetric MTT viability assay. The influence of HS and CS on their cytotoxic activity was evaluated by using HS/CS expressing and HS/CS deficient cell lines. The ability of soluble HS and CS to inhibit the cytotoxic activity of the peptides and the peptides' affinity for HS and CS were also investigated. Results The 9-mer peptides displayed selective anticancer activity. Cells expressing HS/CS were equally or more susceptible to the peptides than cells not expressing HS/CS. The peptides displayed a higher affinity for HS compared to CS, and exogenously added HS inhibited the cytotoxic effect of the peptides. Conclusions In contrast to the previously reported inhibitory effect of HS on LfcinB, the present study shows that the cytotoxic activity of small lytic peptides was increased or not affected by cell surface HS.

  19. Cooperation between Epstein-Barr virus immune evasion proteins spreads protection from CD8+ T cell recognition across all three phases of the lytic cycle.

    Directory of Open Access Journals (Sweden)

    Laura L Quinn

    2014-08-01

    Full Text Available CD8+ T cell responses to Epstein-Barr virus (EBV lytic cycle expressed antigens display a hierarchy of immunodominance, in which responses to epitopes of immediate-early (IE and some early (E antigens are more frequently observed than responses to epitopes of late (L expressed antigens. It has been proposed that this hierarchy, which correlates with the phase-specific efficiency of antigen presentation, may be due to the influence of viral immune-evasion genes. At least three EBV-encoded genes, BNLF2a, BGLF5 and BILF1, have the potential to inhibit processing and presentation of CD8+ T cell epitopes. Here we examined the relative contribution of these genes to modulation of CD8+ T cell recognition of EBV lytic antigens expressed at different phases of the replication cycle in EBV-transformed B-cells (LCLs which spontaneously reactivate lytic cycle. Selective shRNA-mediated knockdown of BNLF2a expression led to more efficient recognition of immediate-early (IE- and early (E-derived epitopes by CD8+ T cells, while knock down of BILF1 increased recognition of epitopes from E and late (L-expressed antigens. Contrary to what might have been predicted from previous ectopic expression studies in EBV-negative model cell lines, the shRNA-mediated inhibition of BGLF5 expression in LCLs showed only modest, if any, increase in recognition of epitopes expressed in any phase of lytic cycle. These data indicate that whilst BNLF2a interferes with antigen presentation with diminishing efficiency as lytic cycle progresses (IE>E>>L, interference by BILF1 increases with progression through lytic cycle (IElytic virus replication, and secondly identify lytic-cycle phase-specific effects that provide mechanistic

  20. Cloning and expression analysis of genes encoding lytic endopeptidases L1 and L5 from Lysobacter sp. strain XL1.

    Science.gov (United States)

    Lapteva, Y S; Zolova, O E; Shlyapnikov, M G; Tsfasman, I M; Muranova, T A; Stepnaya, O A; Kulaev, I S; Granovsky, I E

    2012-10-01

    Lytic enzymes are the group of hydrolases that break down structural polymers of the cell walls of various microorganisms. In this work, we determined the nucleotide sequences of the Lysobacter sp. strain XL1 alpA and alpB genes, which code for, respectively, secreted lytic endopeptidases L1 (AlpA) and L5 (AlpB). In silico analysis of their amino acid sequences showed these endopeptidases to be homologous proteins synthesized as precursors similar in structural organization: the mature enzyme sequence is preceded by an N-terminal signal peptide and a pro region. On the basis of phylogenetic analysis, endopeptidases AlpA and AlpB were assigned to the S1E family [clan PA(S)] of serine peptidases. Expression of the alpA and alpB open reading frames (ORFs) in Escherichia coli confirmed that they code for functionally active lytic enzymes. Each ORF was predicted to have the Shine-Dalgarno sequence located at a canonical distance from the start codon and a potential Rho-independent transcription terminator immediately after the stop codon. The alpA and alpB mRNAs were experimentally found to be monocistronic; transcription start points were determined for both mRNAs. The synthesis of the alpA and alpB mRNAs was shown to occur predominantly in the late logarithmic growth phase. The amount of alpA mRNA in cells of Lysobacter sp. strain XL1 was much higher, which correlates with greater production of endopeptidase L1 than of L5.

  1. AtlA functions as a peptidoglycan lytic transglycosylase in the Neisseria gonorrhoeae type IV secretion system.

    Science.gov (United States)

    Kohler, Petra L; Hamilton, Holly L; Cloud-Hansen, Karen; Dillard, Joseph P

    2007-08-01

    Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We characterized the enzymatic function of AtlA in order to examine its role in the type IV secretion system. Purified AtlA was found to degrade macromolecular peptidoglycan and to produce 1,6-anhydro peptidoglycan monomers, characteristic of lytic transglycosylase activity. We found that AtlA can functionally replace the lambda endolysin to lyse Escherichia coli. In contrast, a sensitive measure of lysis demonstrated that AtlA does not lyse gonococci expressing it or gonococci cocultured with an AtlA-expressing strain. The gonococcal type IV secretion system secretes DNA during growth. A deletion of ltgX or a substitution in the putative active site of AtlA severely decreased DNA secretion. These results indicate that AtlA and LtgX are actively involved in type IV secretion and that AtlA is not involved in lysis of gonococci to release DNA. This is the first demonstration that a type IV secretion peptidoglycanase has lytic transglycosylase activity. These data show that AtlA plays a role in type IV secretion of DNA that requires peptidoglycan breakdown without cell lysis.

  2. Fungi that Infect Humans.

    Science.gov (United States)

    Köhler, Julia R; Hube, Bernhard; Puccia, Rosana; Casadevall, Arturo; Perfect, John R

    2017-06-01

    Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and resistance to immune defenses, including elevated body temperatures. Morphogenesis between small round, detachable cells and long, connected cells is the mechanism by which fungi solve problems of locomotion around or through host barriers. Secretion of lytic enzymes, and uptake systems for the released nutrients, are necessary if a fungus is to nutritionally utilize human tissue. Last, the potent human immune system evolved in the interaction with potential fungal pathogens, so few fungi meet all four conditions for a healthy human host. Paradoxically, the advances of modern medicine have made millions of people newly susceptible to fungal infections by disrupting immune defenses. This article explores how different members of four fungal phyla use different strategies to fulfill the four criteria to infect humans: the Entomophthorales, the Mucorales, the Ascomycota, and the Basidiomycota. Unique traits confer human pathogenic potential on various important members of these phyla: pathogenic Onygenales comprising thermal dimorphs such as Histoplasma and Coccidioides ; the Cryptococcus spp. that infect immunocompromised as well as healthy humans; and important pathogens of immunocompromised patients- Candida , Pneumocystis , and Aspergillus spp. Also discussed are agents of neglected tropical diseases important in global health such as mycetoma and paracoccidiomycosis and common pathogens rarely implicated in serious illness such as dermatophytes. Commensalism is considered, as well as parasitism, in shaping genomes and physiological systems of hosts and fungi during evolution.

  3. Quantitative multi-target RNA profiling in Epstein-Barr virus infected tumor cells.

    Science.gov (United States)

    Greijer, A E; Ramayanti, O; Verkuijlen, S A W M; Novalić, Z; Juwana, H; Middeldorp, J M

    2017-03-01

    Epstein-Barr virus (EBV) is etiologically linked to multiple acute, chronic and malignant diseases. Detection of EBV-RNA transcripts in tissues or biofluids besides EBV-DNA can help in diagnosing EBV related syndromes. Sensitive EBV transcription profiling yields new insights on its pathogenic role and may be useful for monitoring virus targeted therapy. Here we describe a multi-gene quantitative RT-PCR profiling method that simultaneously detects a broad spectrum (n=16) of crucial latent and lytic EBV transcripts. These transcripts include (but are not restricted to), EBNA1, EBNA2, LMP1, LMP2, BARTs, EBER1, BARF1 and ZEBRA, Rta, BGLF4 (PK), BXLF1 (TK) and BFRF3 (VCAp18) all of which have been implicated in EBV-driven oncogenesis and viral replication. With this method we determine the amount of RNA copies per infected (tumor) cell in bulk populations of various origin. While we confirm the expected RNA profiles within classic EBV latency programs, this sensitive quantitative approach revealed the presence of rare cells undergoing lytic replication. Inducing lytic replication in EBV tumor cells supports apoptosis and is considered as therapeutic approach to treat EBV-driven malignancies. This sensitive multi-primed quantitative RT-PCR approach can provide broader understanding of transcriptional activity in latent and lytic EBV infection and is suitable for monitoring virus-specific therapy responses in patients with EBV associated cancers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Production of thyrotropin receptor antibodies in acute phase of infectious mononucleosis due to Epstein-Barr virus primary infection: a case report of a child.

    Science.gov (United States)

    Nagata, Keiko; Okuno, Keisuke; Ochi, Marika; Kumata, Keisuke; Sano, Hitoshi; Yoneda, Naohiro; Ueyama, Jun-Ichi; Matsushita, Michiko; Kuwamoto, Satoshi; Kato, Masako; Murakami, Ichiro; Kanzaki, Susumu; Hayashi, Kazuhiko

    2015-01-01

    Various autoantibodies have been reported to be detected during the progression of infectious mononucleosis. We observed a case of infectious mononucleosis due to Epstein-Barr virus primary infection for 2 months, and noticed the transiently increased titer of thyrotropin receptor autoantibodies detected at the acute phase on the 3rd day after admission. At that time, real-time quantitative PCR also revealed the mRNA expressions of an immediate early lytic gene, BZLF1, and a latent gene, EBNA2. The expression of BZLF1 mRNA means that Epstein-Barr virus infects lytically, and EBNA2 protein has an important role in antibody production as well as the establishment of Epstein-Barr virus latency. These results suggest that Epstein-Barr virus lytic infection is relevant to thyrotropin receptor autoantibody production. Thyrotropin receptor autoantibodies stimulate thyroid follicular cells to produce excessive thyroid hormones and cause Graves' disease. Recently, we reported the thyrotropin receptor autoantibody production from thyrotropin receptor autoantibody-predisposed Epstein-Barr virus-infected B cells by the induction of Epstein-Barr virus lytic infection in vitro. This case showed in vivo findings consistent with our previous reports, and is important to consider the pathophysiology of Graves' disease and one of the mechanisms of autoimmunity.

  5. Deletion of Lytic Transglycosylases Increases Beta-Lactam Resistance in Shewanella oneidensis

    Science.gov (United States)

    Yin, Jianhua; Sun, Yiyang; Sun, Yijuan; Yu, Zhiliang; Qiu, Juanping; Gao, Haichun

    2018-01-01

    Production of chromosome-encoded β-lactamases confers resistance to β-lactams in many Gram-negative bacteria. Some inducible β-lactamases, especially the class C β-lactamase AmpC in Enterobacteriaceae, share a common regulatory mechanism, the ampR-ampC paradigm. Induction of ampC is intimately linked to peptidoglycan recycling, and the LysR-type transcriptional regulator AmpR plays a central role in the process. However, our previous studies have demonstrated that the expression of class D β-lactamase gene blaA in Shewanella oneidensis is distinct from the established paradigm since an AmpR homolog is absent and major peptidoglycan recycling enzymes play opposite roles in β-lactamase expression. Given that lytic transglycosylases (LTs), a class of peptidoglycan hydrolases cleaving the β-1,4 glycosidic linkage in glycan strands of peptidoglycan, can disturb peptidoglycan recycling, and thus may affect induction of blaA. In this study, we investigated impacts of such enzymes on susceptibility to β-lactams. Deletion of three LTs (SltY, MltB and MltB2) increased β-lactam resistance, while four other LTs (MltD, MltD2, MltF, and Slt2) seemed dispensable to β-lactam resistance. The double LT mutants ΔmltBΔmltB2 and ΔsltYΔmltB2 had β-lactam resistance stronger than any of the single mutants. Deletion of ampG (encoding permease AmpG) and mrcA (encoding penicillin binding protein 1a, PBP1a) from both double LT mutants further increased the resistance to β-lactams. Notably, all increased β-lactam resistance phenotypes were in accordance with enhanced blaA expression. Although significant, the increase in β-lactamase activity after inactivating LTs is much lower than that produced by PBP1a inactivation. Our data implicate that LTs play important roles in blaA expression in S. oneidensis. PMID:29403465

  6. Bacteriophage and lytic enzymes - can they help us in the war with antibiotic resistant bacteria

    International Nuclear Information System (INIS)

    Trudil, D.; Rainina, E.

    2009-01-01

    Drug-resistant pathogens are a growing menace to all people, regardless of age, or socioeconomic background. They endanger people industrial societies like the United States, as well as in less developed nations and are even causing problems in military field hospitals. From Streptococcus pneumoniae to Staphylococcus, C. difficile, and multidrug-resistant TB, the list is growing. The threat of engineered microorganisms further complicates the interaction between man and Mother Nature. Additionally, although antibiotics were specifically designed for treating human health emergencies, their use for raising livestock animals has expanded. In the US, large amounts of antibiotics are routinely mixed into feed in order to promote growth rather than combat disease and as prophylactic treatment to offset unnatural diets and unhealthy living conditions. U.S.-raised animals in the 1950s received 2 million pounds per year of antibiotics in their feed compared to 50 million pounds today-a 2,500-percent increase. A large percentage of these drugs pass into the environment. In fact, prior to 1995, when fluoroquinolones were first approved to treat poultry, very few fluoroquinolone-resistant Campylobacter were found in people with foodborne diseases in the United States. After the approval, however, many more fluoroquinolone-resistant bacteria were found in humans and in poultry from slaughter plants and retail stores. The threat to our food supply becomes a threat to security. What can be done? One approach is to treat bacterial diseases by the use of bacteriophages. Phages are very small viruses that destroy by lysing select bacteria. The idea of using phage as a therapy for infectious bacterial diseases was first proposed by d'Herelle around World War I and over 80 years bacteriophage has been a key tool of healthcare professionals within Eastern Europe. More recently professionals in the USA and Western Europe have isolated and developed specific lytic components which have

  7. Latency-Associated Expression of Human Cytomegalovirus US28 Attenuates Cell Signaling Pathways To Maintain Latent Infection

    Directory of Open Access Journals (Sweden)

    Benjamin A. Krishna

    2017-12-01

    Full Text Available Reactivation of human cytomegalovirus (HCMV latent infection from early myeloid lineage cells constitutes a threat to immunocompromised or immune-suppressed individuals. Consequently, understanding the control of latency and reactivation to allow targeting and killing of latently infected cells could have far-reaching clinical benefits. US28 is one of the few viral genes that is expressed during latency and encodes a cell surface G protein-coupled receptor (GPCR, which, during lytic infection, is a constitutive cell-signaling activator. Here we now show that in monocytes, which are recognized sites of HCMV latency in vivo, US28 attenuates multiple cell signaling pathways, including mitogen-activated protein (MAP kinase and NF-κB, and that this is required to establish a latent infection; viruses deleted for US28 initiate a lytic infection in infected monocytes. We also show that these monocytes then become potent targets for the HCMV-specific host immune response and that latently infected cells treated with an inverse agonist of US28 also reactivate lytic infection and similarly become immune targets. Consequently, we suggest that the use of inhibitors of US28 could be a novel immunotherapeutic strategy to reactivate the latent viral reservoir, allowing it to be targeted by preexisting HCMV-specific T cells.

  8. Volume of Lytic Vertebral Body Metastatic Disease Quantified Using Computed Tomography–Based Image Segmentation Predicts Fracture Risk After Spine Stereotactic Body Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thibault, Isabelle [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Centre Hospitalier de L' Universite de Québec–Université Laval, Quebec, Quebec (Canada); Whyne, Cari M. [Orthopaedic Biomechanics Laboratory, Sunnybrook Research Institute, Department of Surgery, University of Toronto, Toronto, Ontario (Canada); Zhou, Stephanie; Campbell, Mikki [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Atenafu, Eshetu G. [Department of Biostatistics, University Health Network, University of Toronto, Toronto, Ontario (Canada); Myrehaug, Sten; Soliman, Hany; Lee, Young K. [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Ebrahimi, Hamid [Orthopaedic Biomechanics Laboratory, Sunnybrook Research Institute, Department of Surgery, University of Toronto, Toronto, Ontario (Canada); Yee, Albert J.M. [Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Sahgal, Arjun, E-mail: arjun.sahgal@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)

    2017-01-01

    Purpose: To determine a threshold of vertebral body (VB) osteolytic or osteoblastic tumor involvement that would predict vertebral compression fracture (VCF) risk after stereotactic body radiation therapy (SBRT), using volumetric image-segmentation software. Methods and Materials: A computational semiautomated skeletal metastasis segmentation process refined in our laboratory was applied to the pretreatment planning CT scan of 100 vertebral segments in 55 patients treated with spine SBRT. Each VB was segmented and the percentage of lytic and/or blastic disease by volume determined. Results: The cumulative incidence of VCF at 3 and 12 months was 14.1% and 17.3%, respectively. The median follow-up was 7.3 months (range, 0.6-67.6 months). In all, 56% of segments were determined lytic, 23% blastic, and 21% mixed, according to clinical radiologic determination. Within these 3 clinical cohorts, the segmentation-determined mean percentages of lytic and blastic tumor were 8.9% and 6.0%, 0.2% and 26.9%, and 3.4% and 15.8% by volume, respectively. On the basis of the entire cohort (n=100), a significant association was observed for the osteolytic percentage measures and the occurrence of VCF (P<.001) but not for the osteoblastic measures. The most significant lytic disease threshold was observed at ≥11.6% (odds ratio 37.4, 95% confidence interval 9.4-148.9). On multivariable analysis, ≥11.6% lytic disease (P<.001), baseline VCF (P<.001), and SBRT with ≥20 Gy per fraction (P=.014) were predictive. Conclusions: Pretreatment lytic VB disease volumetric measures, independent of the blastic component, predict for SBRT-induced VCF. Larger-scale trials evaluating our software are planned to validate the results.

  9. A comparative study on the activity of fungal lytic polysaccharide monooxygenases for the depolymerization of cellulose in soybean spent flakes.

    Science.gov (United States)

    Pierce, Brian C; Agger, Jane Wittrup; Zhang, Zhenghong; Wichmann, Jesper; Meyer, Anne S

    2017-09-08

    Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes capable of the oxidative breakdown of polysaccharides. They are of industrial interest due to their ability to enhance the enzymatic depolymerization of recalcitrant substrates by glycoside hydrolases. In this paper, twenty-four lytic polysaccharide monooxygenases (LPMOs) expressed in Trichoderma reesei were evaluated for their ability to oxidize the complex polysaccharides in soybean spent flakes, an abundant and industrially relevant substrate. TrCel61A, a soy-polysaccharide-active AA9 LPMO from T. reesei, was used as a benchmark in this evaluation. In total, seven LPMOs demonstrated activity on pretreated soy spent flakes, with the products from enzymatic treatments evaluated using mass spectrometry and high performance anion exchange chromatography. The hydrolytic boosting effect of the top-performing enzymes was evaluated in combination with endoglucanase and beta-glucosidase. Two enzymes (TrCel61A and Aspte6) showed the ability to release more than 36% of the pretreated soy spent flake glucose - a greater than 75% increase over the same treatment without LPMO addition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Crystallization and preliminary X-ray diffraction analysis of the lytic transglycosylase MltE from Escherichia coli

    International Nuclear Information System (INIS)

    Artola-Recolons, Cecilia; Llarrull, Leticia I.; Lastochkin, Elena; Mobashery, Shahriar; Hermoso, Juan A.

    2010-01-01

    Crystals of the lytic transglycosylase MltE from E. coli were grown using the microbatch method and diffracted to a resolution of 2.1 Å. MltE from Escherichia coli (193 amino acids, 21 380 Da) is a lytic transglycosylase that initiates the first step of cell-wall recycling. This enzyme is responsible for the cleavage of the cell-wall peptidoglycan at the β-1,4-glycosidic bond between the N-acetylglucosamine and N-acetylmuramic acid units. At the end this reaction generates a disaccharide that is internalized and initiates the recycling process. To obtain insights into the biological functions of MltE, crystallization trials were performed and crystals of MltE protein that were suitable for X-ray diffraction analysis were obtained. The MltE protein of E. coli was crystallized using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture consisting of 28% polyethylene glycol 4000, 0.1 M Tris pH 8.4 and 0.2 M magnesium chloride. Further optimization was performed using the microbatch technique. Single crystals were obtained that belonged to the orthorhombic space group C222 1 , with unit-cell parameters a = 123.32, b = 183.93, c = 35.29 Å, and diffracted to a resolution of 2.1 Å

  11. Listeria monocytogenes has a functional chitinolytic system and an active lytic polysaccharide monooxygenase

    DEFF Research Database (Denmark)

    Paspaliari, Dafni Katerina; Loose, Jennifer S. M.; Larsen, Marianne Halberg

    2015-01-01

    Chitinases and chitin-active lytic polysaccharide monooxygenases (LPMOs) are most commonly associated with chitin metabolism, but are also reported as virulence factors in pathogenic bacteria. Listeria monocytogenes, a well-known virulent bacterium, possesses two chitinases (ChiA and ChiB) and a ......Chitinases and chitin-active lytic polysaccharide monooxygenases (LPMOs) are most commonly associated with chitin metabolism, but are also reported as virulence factors in pathogenic bacteria. Listeria monocytogenes, a well-known virulent bacterium, possesses two chitinases (ChiA and Chi...... but different product profiles depending on the substrate. In LPMO-chitinase synergy experiments, CBP21 is able to boost the activity of both ChiA and ChiB more than LmLPMO10. Product analysis of the synergy assays revealed that the chitinases were unable to efficiently hydrolyse the LPMO products...... (chitooligosaccharide aldonic acids) with a degree of polymerization below four (ChiA and SmChiC) or three (ChiB). Gene transcription and protein expression analysis showed that LmLPMO10 is neither highly transcribed, nor abundantly secreted during the growth of L. monocytogenes in a chitin-containing medium...

  12. Comparison of MGIT and Myco/F lytic liquid-based blood culture systems for recovery of Mycobacterium tuberculosis from pleural fluid.

    Science.gov (United States)

    Harausz, Elizabeth; Lusiba, John Kafuluma; Nsereko, Mary; Johnson, John L; Toossi, Zahra; Ogwang, Sam; Boom, W Henry; Joloba, Moses L

    2015-04-01

    The specificities and sensitivities of the Bactec mycobacterial growth indicator tube (MGIT) system for the recovery of Mycobacterium tuberculosis from pleural fluid are not statistically different than those of the Myco/F lytic liquid culture system. The time to positivity is shorter in the MGIT system (12.7 versus 20.7 days, respectively; P=0.007). The Myco/F lytic culture system may be an alternative to the MGIT system for diagnosing pleural tuberculosis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Phage adsorption and lytic propagation in Lactobacillus plantarum: Could host cell starvation affect them?

    OpenAIRE

    Briggiler Marc?, Mari?ngeles; Reinheimer, Jorge; Quiberoni, Andrea

    2015-01-01

    Background Bacteriophages constitute a great threat to the activity of lactic acid bacteria used in industrial processes. Several factors can influence the infection cycle of bacteriophages. That is the case of the physiological state of host cells, which could produce inhibition or delay of the phage infection process. In the present work, the influence of Lactobacillus plantarum host cell starvation on phage B1 adsorption and propagation was investigated. Result First, cell growth kinetics ...

  14. MUREIN-METABOLIZING ENZYMES FROM ESCHERICHIA-COLI - SEQUENCE-ANALYSIS AND CONTROLLED OVEREXPRESSION OF THE SLT GENE, WHICH ENCODES THE SOLUBLE LYTIC TRANSGLYCOSYLASE

    NARCIS (Netherlands)

    ENGEL, H; KAZEMIER, B; KECK, W

    The complete nucleotide sequence of the slt gene encoding the soluble lytic transglycosylase (Slt; EC 3.2.1.-) from Escherichia coli has been determined. The largest open reading frame identified on a 2.5-kb PvuII-SalI fragment indicates that the enzyme is translated as a preprotein of either 654 or

  15. Latent and lytic HHV-8 mRNA expression in PBMCs and Kaposi's sarcoma skin biopsies of AIDS Kaposi's sarcoma patients

    NARCIS (Netherlands)

    Polstra, Abeltje M.; Goudsmit, Jaap; Cornelissen, Marion

    2003-01-01

    Human herpes virus 8 (HHV-8) is associated with all clinical forms of Kaposi's sarcoma. HHV-8 DNA is present in Kaposi's sarcoma biopsies and is observed regularly in saliva and less consistently in blood of Kaposi's sarcoma patients. The expression pattern of latent (ORF 73) and lytic (vGCR,

  16. Oxidative cleavage and hydrolytic boosting of cellulose in soybean spent flakes by Trichoderma reesei Cel61A lytic polysaccharide monooxygenase.

    Science.gov (United States)

    Pierce, Brian C; Agger, Jane Wittrup; Wichmann, Jesper; Meyer, Anne S

    2017-03-01

    The auxiliary activity family 9 (AA9) copper-dependent lytic polysaccharide monooxygenase (LPMO) from Trichoderma reesei (EG4; TrCel61A) was investigated for its ability to oxidize the complex polysaccharides from soybean. The substrate specificity of the enzyme was assessed against a variety of substrates, including both soy spent flake, a by-product of the soy food industry, and soy spent flake pretreated with sodium hydroxide. Products from enzymatic treatments were analyzed using mass spectrometry and high performance anion exchange chromatography. We demonstrate that TrCel61A is capable of oxidizing cellulose from both pretreated soy spent flake and phosphoric acid swollen cellulose, oxidizing at both the C1 and C4 positions. In addition, we show that the oxidative activity of TrCel61A displays a synergistic effect capable of boosting endoglucanase activity, and thereby substrate depolymerization of soy cellulose, by 27%. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Combined Inhibition of the BMP pathway and the RANK-RANKL axis in a Mixed Lytic/blastic Prostate Cancer Lesion

    Science.gov (United States)

    Virk, Mandeep S.; Alaee, Farhang; Petrigliano, Frank A.; Sugiyama, Osamu; Chatziioannou, Arion F.; Stout, David; Dougall, William C.; Lieberman, Jay R.

    2010-01-01

    The purpose of this study was to investigate the influence of combined inhibition of RANKL (receptor activator of nuclear factor kappa-B ligand) and bone morphogenetic protein (BMP) activity in a mixed lytic/blastic prostate cancer lesion in bone. Human prostate cancer cells (C4 2b) were injected into immunocompromised mice using an intratibial injection model to create mixed lytic/blastic lesions. RANK-Fc, a recombinant RANKL antagonist, was injected subcutaneously three times a week (10mg/kg) to inhibit RANKL and subsequent formation, function and survival of osteoclasts. Inhibition of BMP activity was achieved by transducing prostate cancer cells ex vivo with a retroviral vector expressing noggin (retronoggin; RN). There were three treatment groups (RANK-Fc treatment, RN treatment and combined RN and RANK-Fc treatment) and two control groups (untreated control and empty vector control for the RN treatment group). The progression of bone lesion and tumor growth was evaluated using plain radiographs, hind limb tumor size, 18F-Fluorodeoxyglucose and 18F-fluoride micro PET-CT, histology and histomorphometry. Treatment with RANK-Fc alone inhibited osteolysis and transformed a mixed lytic/blastic lesion into an osteoblastic phenotype. Treatment with RN alone inhibited the osteoblastic component in a mixed lytic/blastic lesion and resulted in formation of smaller osteolytic bone lesion with smaller soft tissue size. The animals treated with both RN and RANK-Fc demonstrated delayed development of bone lesions, inhibition of osteolysis, small soft tissue tumors and preservation of bone architecture with less tumor induced new bone formation. This study suggests that combined inhibition of the RANKL and the BMP pathway may be an effective biologic therapy to inhibit the progression of established mixed lytic/blastic prostate cancer lesions in bone. PMID:21073986

  18. PLAG (1-Palmitoyl-2-Linoleoyl-3-Acetyl-rac-Glycerol Modulates Eosinophil Chemotaxis by Regulating CCL26 Expression from Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Jinseon Jeong

    Full Text Available Increased number of eosinophils in the circulation and sputum is associated with the severity of asthma. The respiratory epithelium produces chemokine (C-C motif ligands (CCL which recruits and activates eosinophils. A chemically synthesized monoacetyl-diglyceride, PLAG (1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol is a major constituent in the antlers of Sika deer (Cervus nippon Temminck which has been used in oriental medicine. This study was aimed to investigate the molecular mechanism of PLAG effect on the alleviation of asthma phenotypes. A549, a human alveolar basal epithelial cell, and HaCaT, a human keratinocyte, were activated by the treatment of interleukin-4 (IL-4, and the expression of chemokines, known to be effective on the induction of eosinophil migration was analyzed by RT-PCR. The expression of IL-4 induced genes was modulated by the co-treatment of PLAG. Especially, CCL26 expression from the stimulated epithelial cells was significantly blocked by PLAG, which was confirmed by ELISA. The transcriptional activity of signal transducer and activator of transcription 6 (STAT6, activated by IL-4 mediated phosphorylation and nuclear translocation, was down-regulated by PLAG in a concentration-dependent manner. In ovalbumin-induced mouse model, the infiltration of immune cells into the respiratory tract was decreased by PLAG administration. Cytological analysis of the isolated bronchoalveolar lavage fluid (BALF cells proved the infiltration of eosinophils was significantly reduced by PLAG. In addition, PLAG inhibited the migration of murine bone marrow-derived eosinophils, and human eosinophil cell line, EoL-1, which was induced by the addition of A549 culture medium.

  19. delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

    Science.gov (United States)

    Cahoon, E B; Cranmer, A M; Shanklin, J; Ohlrogge, J B

    1994-11-04

    delta 6 Hexadecenoic acid (16:1 delta 6) composes more than 80% of the seed oil of Thunbergia alata. Studies were conducted to determine the biosynthetic origin of the double bond of this unusual fatty acid. Assays of fractions of developing T. alata seed endosperm with [1-14C]palmitoyl (16:0)-acyl carrier protein (ACP) revealed the presence of a soluble delta 6 desaturase activity. This activity was greatest when 16:0-ACP was provided as a substrate, whereas no desaturation of the coenzyme A ester of this fatty acid was detected. In addition, delta 6 16:0-ACP desaturase activity in T. alata endosperm extracts was dependent on the presence of ferredoxin and molecular oxygen and was stimulated by catalase. To further characterize this enzyme, a cDNA encoding a diverged acyl-ACP desaturase was isolated from a T. alata endosperm cDNA library using polymerase chain reaction with degenerate oligonucleotides corresponding to conserved amino acid sequences in delta 9 stearoyl (18:0)- and delta 4 16:0-ACP desaturases. The primary structure of the mature peptide encoded by this cDNA shares 66% identity with the mature castor delta 9 18:0-ACP desaturase and 57% identity with the mature coriander delta 4 16:0-ACP desaturase. Extracts of Escherichia coli that express the T. alata cDNA catalyzed the delta 6 desaturation of 16:0-ACP. These results demonstrate that 16:1 delta 6 in T. alata endosperm is formed by the activity of a soluble delta 6 16:0-ACP desaturase that is structurally related to the delta 9 18:0- and delta 4 16:0-ACP desaturases. Implications of this work to an understanding of active site structures of acyl-ACP desaturases are discussed.

  20. Surface interactions, thermodynamics and topography of binary monolayers of Insulin with dipalmitoylphosphatidylcholine and 1-palmitoyl-2-oleoylphosphatidylcholine at the air/water interface.

    Science.gov (United States)

    Grasso, E J; Oliveira, R G; Maggio, B

    2016-02-15

    The molecular packing, thermodynamics and surface topography of binary Langmuir monolayers of Insulin and DPPC (dipalmitoylphosphatidylcholine) or POCP (1-palmitoyl-2-oleoylphosphatidylcholine) at the air/water interface on Zn(2+) containing solutions were studied. Miscibility and interactions were ascertained by the variation of surface pressure-mean molecular area isotherms, surface compressional modulus and surface (dipole) potential with the film composition. Brewster Angle Microscopy was used to visualize the surface topography of the monolayers. Below 20mN/m Insulin forms stable homogenous films with DPPC and POPC at all mole fractions studied (except for films with XINS=0.05 at 10mN/m where domain coexistence was observed). Above 20mN/m, a segregation process between mixed phases occurred in all monolayers without squeezing out of individual components. Under compression the films exhibit formation of a viscoelastic or kinetically trapped organization leading to considerable composition-dependent hysteresis under expansion that occurs with entropic-enthalpic compensation. The spontaneously unfavorable interactions of Insulin with DPPC are driven by favorable enthalpy that is overcome by unfavorable entropic ordering; in films with POPC both the enthalpic and entropic effects are unfavorable. The surface topography reveals domain coexistence at relatively high pressure showing a striped appearance. The interactions of Insulin with two major membrane phospholipids induces composition-dependent and long-range changes of the surface organization that ought to be considered in the context of the information-transducing capabilities of the hormone for cell functioning. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Early events associated with infection of Epstein-Barr virus infection of primary B-cells.

    Directory of Open Access Journals (Sweden)

    Sabyasachi Halder

    2009-09-01

    Full Text Available Epstein Barr virus (EBV is closely associated with the development of a vast number of human cancers. To develop a system for monitoring early cellular and viral events associated with EBV infection a self-recombining BAC containing 172-kb of the Epstein Barr virus genome BAC-EBV designated as MD1 BAC (Chen et al., 2005, J.Virology was used to introduce an expression cassette of green fluorescent protein (GFP by homologous recombination, and the resultant BAC clone, BAC-GFP-EBV was transfected into the HEK 293T epithelial cell line. The resulting recombinant GFP EBV was induced to produce progeny virus by chemical inducer from the stable HEK 293T BAC GFP EBV cell line and the virus was used to immortalize human primary B-cell as monitored by green fluorescence and outgrowth of the primary B cells. The infection, B-cell activation and cell proliferation due to GFP EBV was monitored by the expression of the B-cell surface antigens CD5, CD10, CD19, CD23, CD39, CD40 , CD44 and the intercellular proliferation marker Ki-67 using Flow cytometry. The results show a dramatic increase in Ki-67 which continues to increase by 6-7 days post-infection. Likewise, CD40 signals showed a gradual increase, whereas CD23 signals were increased by 6-12 hours, maximally by 3 days and then decreased. Monitoring the viral gene expression pattern showed an early burst of lytic gene expression. This up-regulation of lytic gene expression prior to latent genes during early infection strongly suggests that EBV infects primary B-cell with an initial burst of lytic gene expression and the resulting progeny virus is competent for infecting new primary B-cells. This process may be critical for establishment of latency prior to cellular transformation. The newly infected primary B-cells can be further analyzed for investigating B cell activation due to EBV infection.

  2. The Epstein-Barr virus DNA load in the peripheral blood of transplant recipients does not accurately reflect the burden of infected cells.

    Science.gov (United States)

    Fink, Susanne; Tsai, Ming-Han; Schnitzler, Paul; Zeier, Martin; Dreger, Peter; Wuchter, Patrick; Bulut, Olcay C; Behrends, Uta; Delecluse, Henri-Jacques

    2017-01-01

    Transplant recipients frequently exhibit an increased Epstein-Barr virus (EBV) load in the peripheral blood. Here, we quantitated the EBV-infected cells in the peripheral blood of these patients and defined the mode of viral infection, latent or lytic. These data indicated that there is no strong correlation between the number of infected cells and the EBV load (EBVL). This can be explained by a highly variable number of EBV copies per infected cell and by lytic replication in some cells. The plasma of these patients did not contain any free infectious viruses, but contained nevertheless EBV DNA, sometimes in large amounts, that probably originates from cell debris and contributed to the total EBVL. Some of the investigated samples carried a highly variable number of infected cells in active latency, characterized by an expression of the Epstein-Barr nuclear antigens (EBNA2) protein. However, a third of the samples expressed neither EBNA2 nor lytic proteins. Patients with an increased EBVL represent a heterogeneous group of patients whose infection cannot be characterized by this method alone. Precise characterization of the origin of an increased EBVL, in particular, in terms of the number of EBV-infected cells, requires additional investigations including the number of EBV-encoded small RNA-positive cells. © 2016 Steunstichting ESOT.

  3. Differential infection properties of three inducible prophages from an epidemic strain of Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    James Chloe E

    2012-09-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is the most common bacterial pathogen infecting the lungs of patients with cystic fibrosis (CF. The Liverpool Epidemic Strain (LES is transmissible, capable of superseding other P. aeruginosa populations and is associated with increased morbidity. Previously, multiple inducible prophages have been found to coexist in the LES chromosome and to constitute a major component of the accessory genome not found in other sequenced P. aerugionosa strains. LES phages confer a competitive advantage in a rat model of chronic lung infection and may, therefore underpin LES prevalence. Here the infective properties of three LES phages were characterised. Results This study focuses on three of the five active prophages (LESφ2, LESφ3 and LESφ4 that are members of the Siphoviridae. All were induced from LESB58 by norfloxacin. Lytic production of LESφ2 was considerably higher than that of LESφ3 and LESφ4. Each phage was capable of both lytic and lysogenic infection of the susceptible P. aeruginosa host, PAO1, producing phage-specific plaque morphologies. In the PAO1 host background, the LESφ2 prophage conferred immunity against LESφ3 infection and reduced susceptibility to LESφ4 infection. Each prophage was less stable in the PAO1 chromosome with substantially higher rates of spontaneous phage production than when residing in the native LESB58 host. We show that LES phages are capable of horizontal gene transfer by infecting P. aeruginosa strains from different sources and that type IV pili are required for infection by all three phages. Conclusions Multiple inducible prophages with diverse infection properties have been maintained in the LES genome. Our data suggest that LESφ2 is more sensitive to induction into the lytic cycle or has a more efficient replicative cycle than the other LES phages.

  4. Isolation and Characterization of Two Lytic Bacteriophages, φSt2 and φGrn1; Phage Therapy Application for Biological Control of Vibrio alginolyticus in Aquaculture Live Feeds.

    Directory of Open Access Journals (Sweden)

    Panos G Kalatzis

    Full Text Available Bacterial infections are a serious problem in aquaculture since they can result in massive mortalities in farmed fish and invertebrates. Vibriosis is one of the most common diseases in marine aquaculture hatcheries and its causative agents are bacteria of the genus Vibrio mostly entering larval rearing water through live feeds, such as Artemia and rotifers. The pathogenic Vibrio alginolyticus strain V1, isolated during a vibriosis outbreak in cultured seabream, Sparus aurata, was used as host to isolate and characterize the two novel bacteriophages φSt2 and φGrn1 for phage therapy application. In vitro cell lysis experiments were performed against the bacterial host V. alginolyticus strain V1 but also against 12 presumptive Vibrio strains originating from live prey Artemia salina cultures indicating the strong lytic efficacy of the 2 phages. In vivo administration of the phage cocktail, φSt2 and φGrn1, at MOI = 100 directly on live prey A. salina cultures, led to a 93% decrease of presumptive Vibrio population after 4 h of treatment. Current study suggests that administration of φSt2 and φGrn1 to live preys could selectively reduce Vibrio load in fish hatcheries. Innovative and environmental friendly solutions against bacterial diseases are more than necessary and phage therapy is one of them.

  5. Dynamics of a viral infection model with delayed CTL response and immune circadian rhythm

    International Nuclear Information System (INIS)

    Bai Zhenguo; Zhou Yicang

    2012-01-01

    This paper studies the global dynamics of a viral infection model that takes into account circadian rhythm and time delay in the CTL response. It is shown that the basic reproduction numbers, R 0 and R 1 , determine the outcome of viral infection. Numerical simulations demonstrate that the changes in the amplitude of lytic component can generate a variety of dynamical patterns, ranging from simple daily oscillation to multi-day dynamics and eventually chaos, whereas time delay can alter the period of oscillation for the larger level of periodic forcing. These results can help to explain the viral oscillation behaviors, which were observed in chronic HBV and HCV infection patients.

  6. Integrative transcriptome and proteome analyses define marked differences between Neospora caninum isolates throughout the tachyzoite lytic cycle.

    Science.gov (United States)

    Horcajo, P; Xia, D; Randle, N; Collantes-Fernández, E; Wastling, J; Ortega-Mora, L M; Regidor-Cerrillo, J

    2017-11-14

    Neospora caninum is one of the main causes of transmissible abortion in cattle. Intraspecific variations in virulence have been widely shown among N. caninum isolates. However, the molecular basis governing such variability have not been elucidated to date. In this study label free LC-MS/MS was used to investigate proteome differences between the high virulence isolate Nc-Spain7 and the low virulence isolate Nc-Spain1H throughout the tachyzoite lytic cycle. The results showed greater differences in the abundance of proteins at invasion and egress with 77 and 62 proteins, respectively. During parasite replication, only 19 proteins were differentially abundant between isolates. The microneme protein repertoire involved in parasite invasion and egress was more abundant in the Nc-Spain1H isolate, which displays a lower invasion rate. Rhoptry and dense granule proteins, proteins related to metabolism and stress responses also showed differential abundances between isolates. Comparative RNA-Seq analyses during tachyzoite egress were also performed, revealing an expression profile of genes associated with the bradyzoite stage in the low virulence Nc-Spain1H isolate. The differences in proteome and RNA expression profiles between these two isolates reveal interesting insights into likely mechanisms involved in specific phenotypic traits and virulence in N. caninum. The molecular basis that governs biological variability in N. caninum and the pathogenesis of neosporosis has not been well-established yet. This is the first study in which high throughput technology of LC-MS/MS and RNA-Seq is used to investigate differences in the proteome and transcriptome between two well-characterized isolates. Both isolates displayed different proteomes throughout the lytic cycle and the transcriptomes also showed marked variations but were inconsistent with the proteome results. However, both datasets identified a pre-bradyzoite status of the low virulence isolate Nc-Spain1H. This study

  7. Comparative genome analysis of novel Podoviruses lytic for hypermucoviscous Klebsiella pneumoniae of K1, K2, and K57 capsular types.

    Science.gov (United States)

    Solovieva, Ekaterina V; Myakinina, Vera P; Kislichkina, Angelina A; Krasilnikova, Valentina M; Verevkin, Vladimir V; Mochalov, Vladimir V; Lev, Anastasia I; Fursova, Nadezhda K; Volozhantsev, Nikolay V

    2018-01-02

    Hypermucoviscous (HV) strains of capsular types K1, K2 and K57 are the most virulent representatives of the Klebsiella pneumoniae species. Eight novel bacteriophages lytic for HV K. pneumoniae were isolated and characterized. Three bacteriophages, KpV41, KpV475, and KpV71 were found to have a lytic activity against mainly K. pneumoniae of capsular type K1. Two phages, KpV74, and KpV763 were lytic for K2 capsular type K. pneumoniae, and the phage KpV767 was specific to K57-type K. pneumoniae only. Two more phages, KpV766, and KpV48 had no capsular specificity. The phage genomes consist of a linear double-stranded DNA of 40,395-44,623bp including direct terminal repeats of 180-246 bp. The G + C contents are 52.3-54.2 % that is slightly lower than that of genomes of K. pneumoniae strains being used for phage propagation. According to the genome structures, sequence similarity and phylogenetic data, the phages are classified within the genus Kp32virus and Kp34virus of subfamily Autographivirinae, family Podoviridae. In the phage genomes, genes encoding proteins with putative motifs of polysaccharide depolymerase were identified. Depolymerase genes of phages KpV71 and KpV74 lytic for hypermucoviscous K. pneumoniae of K1 and K2 capsular type, respectively, were cloned and expressed in Escherichia coli, and the recombinant gene products were purified. The specificity and polysaccharide-degrading activity of the recombinant depolymerases were demonstrated. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A study by nitrogen-15 nuclear magnetic resonance spectroscopy of the state of histidine in the catalytic triad of α-lytic protease

    International Nuclear Information System (INIS)

    Bachovchin, W.W.; Roberts, J.D.

    1978-01-01

    The ionization behaviour of the histidine of the catalytic triad of α-lytic protease using N-15 NMR spectroscopy is studied. This technique is especially informative about the protonation, hydrogen-bond formation, and tautomeric equilibrium of imidazole rings. The efficient and specific incorporation of N-15 labelled histidine into α-lytic protease was achieved by inducing and isolating an auxotroph of myxobacter 495 for which histidine is an essential amino acid. The results show that histidine of the catalytic triad of α-lytic protease appears to have a base strength which is essentially normal for an imidazole derivative but, in the pH range where the enzymatic activity is high, the histidine tautomer is favoured with the hydrogen located on N3 (π), as the result of hydrogen bonding to the asparate anion and possible the serine hydroxyl. Thus, the N-15 NMR shifts support the general geometry postulated for the ''charge-relay'' mechanism but not the idea of an unusually weakly basic histidine or an unusually strongly basic asparate carboxylate anion. (A.G.)

  9. Expression of Pseudomonas aeruginosa transposable phages in Pseudomonas putida cells. I. Establishment of lysogeny and lytic growth efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunova, S.A.; Yanenko, A.S.; Akhverdyan, V.Z.; Reulets, M.A.; Krylov, V.N.

    1986-03-01

    Expression of the genomes of Pseudomonas aeruginosa transposable phages (TP) in the cells of a heterologous host, P. putida PpGl, was studied. A high efficiency of TP lytic growth in PpGl cells was obtained both after zygotic induction following RP4::TP plasmid transfer and after thermoinduction of PpGl cells lysogenic for thermoinducible prophage D3112cts15. Characteristic for PpGl cells was a high TP yield (20-25 phage D3112cts15 particles per cell), which was evidence of a high level of TP transposition in cells of this species. The frequency of RP4::TP transfer into PpGl and PA01 cells was equal, but the lysogeny detection rat was somewhat lower in PpGl. Pseudomonas aeruginosa TP can integrate into the PpGl chromosome, producing inducible lysogens. The presence of RP4 is not necessary for the expression of the TP genome in PpGl cells. The D3112cts15 TP may be used for interspecific transduction of plasmids and chromosomal markers.

  10. Functional Elucidation of Nemopilema nomurai and Cyanea nozakii Nematocyst Venoms' Lytic Activity Using Mass Spectrometry and Zymography.

    Science.gov (United States)

    Yue, Yang; Yu, Huahua; Li, Rongfeng; Xing, Ronge; Liu, Song; Li, Kecheng; Wang, Xueqin; Chen, Xiaolin; Li, Pengcheng

    2017-01-26

    Medusozoans utilize explosively discharging penetrant nematocysts to inject venom into prey. These venoms are composed of highly complex proteins and peptides with extensive bioactivities, as observed in vitro. Diverse enzymatic toxins have been putatively identified in the venom of jellyfish, Nemopilema nomurai and Cyanea nozakii , through examination of their proteomes and transcriptomes. However, functional examination of putative enzymatic components identified in proteomic approaches to elucidate potential bioactivities is critically needed. In this study, enzymatic toxins were functionally identified using a combined approach consisting of in gel zymography and liquid chromatography tandem mass spectrometry (LC-MS/MS). The potential roles of metalloproteinases and lipases in hemolytic activity were explored using specific inhibitors. Zymography indicated that nematocyst venom possessed protease-, lipase- and hyaluronidase-class activities. Further, proteomic approaches using LC-MS/MS indicated sequence homology of proteolytic bands observed in zymography to extant zinc metalloproteinase-disintegrins and astacin metalloproteinases. Moreover, pre-incubation of the metalloproteinase inhibitor batimastat with N . nomurai nematocyst venom resulted in an approximate 62% reduction of hemolysis compared to venom exposed sheep erythrocytes, suggesting that metalloproteinases contribute to hemolytic activity. Additionally, species within the molecular mass range of 14-18 kDa exhibited both egg yolk and erythrocyte lytic activities in gel overlay assays. For the first time, our findings demonstrate the contribution of jellyfish venom metalloproteinase and suggest the involvement of lipase species to hemolytic activity. Investigations of this relationship will facilitate a better understanding of the constituents and toxicity of jellyfish venom.

  11. Expression of Pseudomonas aeruginosa transposable phages in Pseudomonas putida cells. I. Establishment of lysogeny and lytic growth efficiency

    International Nuclear Information System (INIS)

    Gorbunova, S.A.; Yanenko, A.S.; Akhverdyan, V.Z.; Reulets, M.A.; Krylov, V.N.

    1986-01-01

    Expression of the genomes of Pseudomonas aeruginosa transposable phages (TP) in the cells of a heterologous host, P. putida PpGl, was studied. A high efficiency of TP lytic growth in PpGl cells was obtained both after zygotic induction following RP4::TP plasmid transfer and after thermoinduction of PpGl cells lysogenic for thermoinducible prophage D3112cts15. Characteristic for PpGl cells was a high TP yield (20-25 phage D3112cts15 particles per cell), which was evidence of a high level of TP transposition in cells of this species. The frequency of RP4::TP transfer into PpGl and PA01 cells was equal, but the lysogeny detection rat was somewhat lower in PpGl. Pseudomonas aeruginosa TP can integrate into the PpGl chromosome, producing inducible lysogens. The presence of RP4 is not necessary for the expression of the TP genome in PpGl cells. The D3112cts15 TP may be used for interspecific transduction of plasmids and chromosomal markers

  12. Poliovirus mutants excreted by a chronically infected hypogammaglobulinemic patient establish persistent infections in human intestinal cells

    International Nuclear Information System (INIS)

    Labadie, Karine; Pelletier, Isabelle; Saulnier, Aure; Martin, Javier; Colbere-Garapin, Florence

    2004-01-01

    Immunodeficient patients whose gut is chronically infected by vaccine-derived poliovirus (VDPV) may excrete large amounts of virus for years. To investigate how poliovirus (PV) establishes chronic infections in the gut, we tested whether it is possible to establish persistent VDPV infections in human intestinal Caco-2 cells. Four type 3 VDPV mutants, representative of the viral evolution in the gut of a hypogammaglobulinemic patient over almost 2 years [J. Virol. 74 (2000) 3001], were used to infect both undifferentiated, dividing cells, and differentiated, polarized enterocytes. A VDPV mutant excreted 36 days postvaccination by the patient was lytic in both types of intestinal cell cultures, like the parental Sabin 3 (S3) strain. In contrast, three VDPVs excreted 136, 442, and 637 days postvaccination, established persistent infections both in undifferentiated cells and in enterocytes. Thus, viral determinants selected between day 36 and 136 conferred on VDPV mutants the capacity to infect intestinal cells persistently. The percentage of persistently VDPV-infected cultures was higher in enterocytes than in undifferentiated cells, implicating cellular determinants involved in the differentiation of enterocytes in persistent VDPV infections. The establishment of persistent infections in enterocytes was not due to poor replication of VDPVs in these cells, but was associated with reduced viral adsorption to the cell surface

  13. Epstein-Barr Virus MicroRNA miR-BART20-5p Suppresses Lytic Induction by Inhibiting BAD-Mediated caspase-3-Dependent Apoptosis.

    Science.gov (United States)

    Kim, Hyoji; Choi, Hoyun; Lee, Suk Kyeong

    2016-02-01

    Epstein-Barr virus (EBV) is a human gammaherpesvirus associated with a variety of tumor types. EBV can establish latency or undergo lytic replication in host cells. In general, EBV remains latent in tumors and expresses a limited repertoire of latent proteins to avoid host immune surveillance. When the lytic cycle is triggered by some as-yet-unknown form of stimulation, lytic gene expression and progeny virus production commence. Thus far, the exact mechanism of EBV latency maintenance and the in vivo triggering signal for lytic induction have yet to be elucidated. Previously, we have shown that the EBV microRNA miR-BART20-5p directly targets the immediate early genes BRLF1 and BZLF1 as well as Bcl-2-associated death promoter (BAD) in EBV-associated gastric carcinoma. In this study, we found that both mRNA and protein levels of BRLF1 and BZLF1 were suppressed in cells following BAD knockdown and increased after BAD overexpression. Progeny virus production was also downregulated by specific knockdown of BAD. Our results demonstrated that caspase-3-dependent apoptosis is a prerequisite for BAD-mediated EBV lytic cycle induction. Therefore, our data suggest that miR-BART20-5p plays an important role in latency maintenance and tumor persistence of EBV-associated gastric carcinoma by inhibiting BAD-mediated caspase-3-dependent apoptosis, which would trigger immediate early gene expression. EBV has an ability to remain latent in host cells, including EBV-associated tumor cells hiding from immune surveillance. However, the exact molecular mechanisms of EBV latency maintenance remain poorly understood. Here, we demonstrated that miR-BART20-5p inhibited the expression of EBV immediate early genes indirectly, by suppressing BAD-induced caspase-3-dependent apoptosis, in addition to directly, as we previously reported. Our study suggests that EBV-associated tumor cells might endure apoptotic stress to some extent and remain latent with the aid of miR-BART20-5p. Blocking the

  14. Modeling of the Ebola Virus Delta Peptide Reveals a Potential Lytic Sequence Motif

    Directory of Open Access Journals (Sweden)

    William R. Gallaher

    2015-01-01

    Full Text Available Filoviruses, such as Ebola and Marburg viruses, cause severe outbreaks of human infection, including the extensive epidemic of Ebola virus disease (EVD in West Africa in 2014. In the course of examining mutations in the glycoprotein gene associated with 2014 Ebola virus (EBOV sequences, a differential level of conservation was noted between the soluble form of glycoprotein (sGP and the full length glycoprotein (GP, which are both encoded by the GP gene via RNA editing. In the region of the proteins encoded after the RNA editing site sGP was more conserved than the overlapping region of GP when compared to a distant outlier species, Tai Forest ebolavirus. Half of the amino acids comprising the “delta peptide”, a 40 amino acid carboxy-terminal fragment of sGP, were identical between otherwise widely divergent species. A lysine-rich amphipathic peptide motif was noted at the carboxyl terminus of delta peptide with high structural relatedness to the cytolytic peptide of the non-structural protein 4 (NSP4 of rotavirus. EBOV delta peptide is a candidate viroporin, a cationic pore-forming peptide, and may contribute to EBOV pathogenesis.

  15. TLR3 deficiency renders astrocytes permissive to herpes simplex virus infection and facilitates establishment of CNS infection in mice

    DEFF Research Database (Denmark)

    Reinert, Line; Harder, Louis Andreas; Holm, Christian

    2012-01-01

    Herpes simplex viruses (HSVs) are highly prevalent neurotropic viruses. While they can replicate lytically in cells of the epithelial lineage, causing lesions on mucocutaneous surfaces, HSVs also establish latent infections in neurons, which act as reservoirs of virus for subsequent reactivation......, it is not known what cell type mediates the role of TLR3 in the immunological control of HSV, and it is not known whether TLR3 sensing occurs prior to or after CNS entry. Here, we show that in mice TLR3 provides early control of HSV-2 infection immediately after entry into the CNS by mediating type I IFN...... responses in astrocytes. Tlr3-/- mice were hypersusceptible to HSV-2 infection in the CNS after vaginal inoculation. HSV-2 exhibited broader neurotropism in Tlr3-/- mice than it did in WT mice, with astrocytes being most abundantly infected. Tlr3-/- mice did not exhibit a global defect in innate immune...

  16. Vaginal Infections

    Science.gov (United States)

    ... gov/ Home Body Your reproductive health Vaginal infections Vaginal infections Help for infections If you have pain, ... infections and how to prevent them. Types of vaginal infections top Two common vaginal infections are bacterial ...

  17. Infective Endocarditis

    Science.gov (United States)

    ... Center > Infective Endocarditis Menu Topics Topics FAQs Infective Endocarditis En español Infective endocarditis is an infection of ... time, congestive heart failure (CHF). What causes infective endocarditis? The infection that leads to endocarditis can be ...

  18. Reduction of Salmonella on chicken meat and chicken skin by combined or sequential application of lytic bacteriophage with chemical antimicrobials.

    Science.gov (United States)

    Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

    2015-08-17

    The effectiveness of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella in vitro and on chicken breast fillets was examined in combination with lauric arginate (LAE) or cetylpyridinium chloride (CPC). In another experiment, a sequential spray application of this bacteriophage (phage) solution on Salmonella inoculated chicken skin after a 20s dip in chemical antimicrobials (LAE, CPC, peracetic acid, or chlorine) was also examined in reducing Salmonella counts on chicken skin. The application of phage in combination with CPC or LAE reduced S. Typhimurium, S. Heidelberg, and S. Enteritidis up to 5 log units in vitro at 4 °C. On chicken breast fillets, phage in combination with CPC or LAE resulted in significant (p<0.05) reductions of Salmonella ranging from 0.5 to 1.3 log CFU/g as compared to control up to 7 days of refrigerated storage. When phage was applied sequentially with chemical antimicrobials, all the treatments resulted in significant reductions of Salmonella. The application of chlorine (30 ppm) and PAA (400 ppm) followed by phage spray (10(9)PFU/ml) resulted in highest Salmonella reductions of 1.6-1.7 and 2.2-2.5l og CFU/cm(2), respectively. In conclusion, the surface applications of phage in combination with LAE or CPC significantly reduced Salmonella counts on chicken breast fillets. However, higher reductions in Salmonella counts were achieved on chicken skin by the sequential application of chemical antimicrobials followed by phage spray. The sequential application of chlorine, PAA, and phage can provide additional hurdles to reduce Salmonella on fresh poultry carcasses or cut up parts. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Functional Elucidation of Nemopilema nomurai and Cyanea nozakii Nematocyst Venoms’ Lytic Activity Using Mass Spectrometry and Zymography

    Science.gov (United States)

    Yue, Yang; Yu, Huahua; Li, Rongfeng; Xing, Ronge; Liu, Song; Li, Kecheng; Wang, Xueqin; Chen, Xiaolin; Li, Pengcheng

    2017-01-01

    Background: Medusozoans utilize explosively discharging penetrant nematocysts to inject venom into prey. These venoms are composed of highly complex proteins and peptides with extensive bioactivities, as observed in vitro. Diverse enzymatic toxins have been putatively identified in the venom of jellyfish, Nemopilema nomurai and Cyanea nozakii, through examination of their proteomes and transcriptomes. However, functional examination of putative enzymatic components identified in proteomic approaches to elucidate potential bioactivities is critically needed. Methods: In this study, enzymatic toxins were functionally identified using a combined approach consisting of in gel zymography and liquid chromatography tandem mass spectrometry (LC-MS/MS). The potential roles of metalloproteinases and lipases in hemolytic activity were explored using specific inhibitors. Results: Zymography indicated that nematocyst venom possessed protease-, lipase- and hyaluronidase-class activities. Further, proteomic approaches using LC-MS/MS indicated sequence homology of proteolytic bands observed in zymography to extant zinc metalloproteinase-disintegrins and astacin metalloproteinases. Moreover, pre-incubation of the metalloproteinase inhibitor batimastat with N. nomurai nematocyst venom resulted in an approximate 62% reduction of hemolysis compared to venom exposed sheep erythrocytes, suggesting that metalloproteinases contribute to hemolytic activity. Additionally, species within the molecular mass range of 14–18 kDa exhibited both egg yolk and erythrocyte lytic activities in gel overlay assays. Conclusion: For the first time, our findings demonstrate the contribution of jellyfish venom metalloproteinase and suggest the involvement of lipase species to hemolytic activity. Investigations of this relationship will facilitate a better understanding of the constituents and toxicity of jellyfish venom. PMID:28134758

  20. Functional Elucidation of Nemopilema nomurai and Cyanea nozakii Nematocyst Venoms’ Lytic Activity Using Mass Spectrometry and Zymography

    Directory of Open Access Journals (Sweden)

    Yang Yue

    2017-01-01

    Full Text Available Background: Medusozoans utilize explosively discharging penetrant nematocysts to inject venom into prey. These venoms are composed of highly complex proteins and peptides with extensive bioactivities, as observed in vitro. Diverse enzymatic toxins have been putatively identified in the venom of jellyfish, Nemopilema nomurai and Cyanea nozakii, through examination of their proteomes and transcriptomes. However, functional examination of putative enzymatic components identified in proteomic approaches to elucidate potential bioactivities is critically needed. Methods: In this study, enzymatic toxins were functionally identified using a combined approach consisting of in gel zymography and liquid chromatography tandem mass spectrometry (LC-MS/MS. The potential roles of metalloproteinases and lipases in hemolytic activity were explored using specific inhibitors. Results: Zymography indicated that nematocyst venom possessed protease-, lipase- and hyaluronidase-class activities. Further, proteomic approaches using LC-MS/MS indicated sequence homology of proteolytic bands observed in zymography to extant zinc metalloproteinase-disintegrins and astacin metalloproteinases. Moreover, pre-incubation of the metalloproteinase inhibitor batimastat with N. nomurai nematocyst venom resulted in an approximate 62% reduction of hemolysis compared to venom exposed sheep erythrocytes, suggesting that metalloproteinases contribute to hemolytic activity. Additionally, species within the molecular mass range of 14–18 kDa exhibited both egg yolk and erythrocyte lytic activities in gel overlay assays. Conclusion: For the first time, our findings demonstrate the contribution of jellyfish venom metalloproteinase and suggest the involvement of lipase species to hemolytic activity. Investigations of this relationship will facilitate a better understanding of the constituents and toxicity of jellyfish venom.

  1. Mutations Inactivating Herpes Simplex Virus 1 MicroRNA miR-H2 Do Not Detectably Increase ICP0 Gene Expression in Infected Cultured Cells or Mouse Trigeminal Ganglia.

    Science.gov (United States)

    Pan, Dongli; Pesola, Jean M; Li, Gang; McCarron, Seamus; Coen, Donald M

    2017-01-15

    Herpes simplex virus 1 (HSV-1) latency entails the repression of productive ("lytic") gene expression. An attractive hypothesis to explain some of this repression involves inhibition of the expression of ICP0, a lytic gene activator, by a viral microRNA, miR-H2, which is completely complementary to ICP0 mRNA. To test this hypothesis, we engineered mutations that disrupt miR-H2 without affecting ICP0 in HSV-1. The mutant virus exhibited drastically reduced expression of miR-H2 but showed wild-type levels of infectious virus production and no increase in ICP0 expression in lytically infected cells, which is consistent with the weak expression of miR-H2 relative to the level of ICP0 mRNA in that setting. Following corneal inoculation of mice, the mutant was not significantly different from wild-type virus in terms of infectious virus production in the trigeminal ganglia during acute infection, mouse mortality, or the rate of reactivation from explanted latently infected ganglia. Critically, the mutant was indistinguishable from wild-type virus for the expression of ICP0 and other lytic genes in acutely and latently infected mouse trigeminal ganglia. The latter result may be related to miR-H2 being less effective in inhibiting ICP0 expression in transfection assays than a host microRNA, miR-138, which has previously been shown to inhibit lytic gene expression in infected ganglia by targeting ICP0 mRNA. Additionally, transfected miR-138 reduced lytic gene expression in infected cells more effectively than miR-H2. While this study provides little support for the hypothesis that miR-H2 promotes latency by inhibiting ICP0 expression, the possibility remains that miR-H2 might target other genes during latency. Herpes simplex virus 1 (HSV-1), which causes a variety of diseases, can establish lifelong latent infections from which virus can reactivate to cause recurrent disease. Latency is the most biologically interesting and clinically vexing feature of the virus. Ever since

  2. Bone marrow edema pattern identification in patients with lytic bone lesions using digital subtraction angiography-like bone subtraction on large-area detector computed tomography.

    Science.gov (United States)

    Gondim Teixeira, Pedro Augusto; Hossu, Gabriela; Lecocq, Sophie; Razeto, Marco; Louis, Matthias; Blum, Alain

    2014-03-01

    The objective of this study was to evaluate the performance of digital subtraction angiography (DSA)-like bone subtraction with 2 different registration methods for the identification of bone marrow edema pattern (BMEP) in patients with lytic bone lesions, using magnetic resonance imaging as the criterion standard. Fifty-five patients with a lytic bone lesion were included in this prospective study with approval from the ethics committee. All patients underwent magnetic resonance imaging and low-dose computed tomographic (CT) perfusion after signing an informed consent. Two CT volumes were used for bone subtraction, which was performed with 2 different algorithms (rigid and nonrigid). Enhancement at the nonlytic bone marrow was considered as a sign of BMEP. Two readers evaluated the images blindly. The presence of BMEP on bone-subtracted CT images was evaluated subjectively and quantitatively. Image quality was assessed. Magnetic resonance imaging was used as the criterion standard. Using a rigid registration method, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT with DSA-like bone subtraction BMEP was 77%, 100%, 100%, 68%, and 85%, respectively. The interobserver agreement was good (κ, 0.782). Image quality was better using a nonrigid registration. With this algorithm, artifacts interfered with image interpretation in only 5% of cases. However, there was a noticeable drop in sensitivity and negative predictive value when a nonrigid algorithm was used: 56% and 52%, respectively. The interobserver agreement was average with a nonrigid subtraction algorithm. Computed tomography with DSA-like bone subtraction is sensitive and highly specific for the identification of BMEP associated with lytic bone lesions. Rigid registering should be preferred, but nonrigid algorithms can be used as a second option when artifacts interfere with image interpretation.

  3. Radiation-induced Epstein-Barr virus reactivation in gastric cancer cells with latent EBV infection.

    Science.gov (United States)

    Nandakumar, Athira; Uwatoko, Futoshi; Yamamoto, Megumi; Tomita, Kazuo; Majima, Hideyuki J; Akiba, Suminori; Koriyama, Chihaya

    2017-07-01

    Epstein-Barr virus, a ubiquitous human herpes virus with oncogenic activity, can be found in 6%-16% of gastric carcinomas worldwide. In Epstein-Barr virus-associated gastric carcinoma, only a few latent genes of the virus are expressed. Ionizing irradiation was shown to induce lytic Epstein-Barr virus infection in lymphoblastoid cell lines with latent Epstein-Barr virus infection. In this study, we examined the effect of ionizing radiation on the Epstein-Barr virus reactivation in a gastric epithelial cancer cell line (SNU-719, an Epstein-Barr virus-associated gastric carcinoma cell line). Irradiation with X-ray (dose = 5 and 10 Gy; dose rate = 0.5398 Gy/min) killed approximately 25% and 50% of cultured SNU-719 cells, respectively, in 48 h. Ionizing radiation increased the messenger RNA expression of immediate early Epstein-Barr virus lytic genes (BZLF1 and BRLF1), determined by real-time reverse transcription polymerase chain reaction, in a dose-dependent manner at 48 h and, to a slightly lesser extent, at 72 h after irradiation. Similar findings were observed for other Epstein-Barr virus lytic genes (BMRF1, BLLF1, and BcLF1). After radiation, the expression of transforming growth factor beta 1 messenger RNA increased and reached a peak in 12-24 h, and the high-level expression of the Epstein-Barr virus immediate early genes can convert latent Epstein-Barr virus infection into the lytic form and result in the release of infectious Epstein-Barr virus. To conclude, Ionizing radiation activates lytic Epstein-Barr virus gene expression in the SNU-719 cell line mainly through nuclear factor kappaB activation. We made a brief review of literature to explore underlying mechanism involved in transforming growth factor beta-induced Epstein-Barr virus reactivation. A possible involvement of nuclear factor kappaB was hypothesized.

  4. Produção, purificação, clonagem e aplicação de enzimas líticas Production, purification, cloning and application of lytic enzymes

    Directory of Open Access Journals (Sweden)

    Luciana Francisco Fleuri

    2005-10-01

    Full Text Available Lytic enzymes such as beta-1,3 glucanases, proteases and chitinases are able to hydrolyse, respectively, beta-1,3 glucans, mannoproteins and chitin, as well as the cell walls of many yeast species. Lytic enzymes are useful in a great variety of applications including the preparation of protoplasts; the extraction of proteins, enzymes, pigments and functional carbohydrates; pre-treatment for the mechanical rupture of cells; degradation of residual yeast cell mass for the preparation of animal feed; analysis of the yeast cell wall structure and composition; study of the yeast cell wall synthesis and the control of pathogenic fungi. This review presents the most important aspects with respect to lytic enzymes, especially their production, purification, cloning and application.

  5. Bacteriophage Infectivity Against Pseudomonas aeruginosa in Saline Conditions

    KAUST Repository

    Scarascia, Giantommaso

    2018-05-02

    Pseudomonas aeruginosa is a ubiquitous member of marine biofilm, and reduces thiosulfate to produce toxic hydrogen sulfide gas. In this study, lytic bacteriophages were isolated and applied to inhibit the growth of P. aeruginosa in planktonic mode at different temperature, pH, and salinity. Bacteriophages showed optimal infectivity at a multiplicity of infection of 10 in saline conditions, and demonstrated lytic abilities over all tested temperature (25, 30, 37, and 45°C) and pH 6–9. Planktonic P. aeruginosa exhibited significantly longer lag phase and lower specific growth rates upon exposure to bacteriophages. Bacteriophages were subsequently applied to P. aeruginosa-enriched biofilm and were determined to lower the relative abundance of Pseudomonas-related taxa from 0.17 to 5.58% in controls to 0.01–0.61% in treated microbial communities. The relative abundance of Alphaproteobacteria, Pseudoalteromonas, and Planococcaceae decreased, possibly due to the phage-induced disruption of the biofilm matrix. Lastly, when applied to mitigate biofouling of ultrafiltration membranes, bacteriophages were determined to reduce the transmembrane pressure increase by 18% when utilized alone, and by 49% when used in combination with citric acid. The combined treatment was more effective compared with the citric acid treatment alone, which reported ca. 30% transmembrane pressure reduction. Collectively, the findings demonstrated that bacteriophages can be used as a biocidal agent to mitigate undesirable P. aeruginosa-associated problems in seawater applications.

  6. Epstein-Barr virus infection and nasopharyngeal carcinoma.

    Science.gov (United States)

    Tsao, Sai Wah; Tsang, Chi Man; Lo, Kwok Wai

    2017-10-19

    Epstein-Barr virus (EBV) is associated with multiple types of human cancer, including lymphoid and epithelial cancers. The closest association with EBV infection is seen in undifferentiated nasopharyngeal carcinoma (NPC), which is endemic in the southern Chinese population. A strong association between NPC risk and the HLA locus at chromosome 6p has been identified, indicating a link between the presentation of EBV antigens to host immune cells and NPC risk. EBV infection in NPC is clonal in origin, strongly suggesting that NPC develops from the clonal expansion of a single EBV-infected cell. In epithelial cells, the default program of EBV infection is lytic replication. However, latent infection is the predominant mode of EBV infection in NPC. The establishment of latent EBV infection in pre-invasive nasopharyngeal epithelium is believed to be an early stage of NPC pathogenesis. Recent genomic study of NPC has identified multiple somatic mutations in the upstream negative regulators of NF-κB signalling. Dysregulated NF-κB signalling may contribute to the establishment of latent EBV infection in NPC. Stable EBV infection and the expression of latent EBV genes are postulated to drive the transformation of pre-invasive nasopharyngeal epithelial cells to cancer cells through multiple pathways.This article is part of the themed issue 'Human oncogenic viruses'. © 2017 The Author(s).

  7. Genetically Engineered Yeast Expressing a Lytic Peptide from Bee Venom (Melittin) Kills Symbiotic Protozoa in the Gut of Formosan Subterranean Termites.

    Science.gov (United States)

    Husseneder, Claudia; Donaldson, Jennifer R; Foil, Lane D

    2016-01-01

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is a costly invasive urban pest in warm and humid regions around the world. Feeding workers of the Formosan subterranean termite genetically engineered yeast strains that express synthetic protozoacidal lytic peptides has been shown to kill the cellulose digesting termite gut protozoa, which results in death of the termite colony. In this study, we tested if Melittin, a natural lytic peptide from bee venom, could be delivered into the termite gut via genetically engineered yeast and if the expressed Melittin killed termites via lysis of symbiotic protozoa in the gut of termite workers and/or destruction of the gut tissue itself. Melittin expressing yeast did kill protozoa in the termite gut within 56 days of exposure. The expressed Melittin weakened the gut but did not add a synergistic effect to the protozoacidal action by gut necrosis. While Melittin could be applied for termite control via killing the cellulose-digesting protozoa in the termite gut, it is unlikely to be useful as a standalone product to control insects that do not rely on symbiotic protozoa for survival.

  8. Rapid Assessment of Resistance to Antibiotic Inhibitors of Protein Synthesis in the Gram-Positive Pathogens, Enterococcus faecalis and Streptococcus pneumoniae, Based on Evaluation of the Lytic Response.

    Science.gov (United States)

    Otero, Fátima; Tamayo, María; Santiso, Rebeca; Gosálvez, Jaime; Bou, Germán; Fernández, José Luis

    2017-04-01

    A novel assay for rapid determination of resistance to antibiotic inhibitors of protein synthesis was developed for the gram-positive pathogens, Enterococcus faecalis and Streptococcus pneumoniae. To this purpose, a lytic response was obtained by a brief incubation with lysozyme or a mixture of lysozyme, Triton X-100, and EDTA for E. faecalis (n = 82) and S. pneumoniae (n = 51), respectively. Lysis was quantified by visualizing the released nucleoids. Antibiotic-susceptible bacteria treated with Clinical and Laboratory Standards Institute (CLSI) breakpoint doses of erythromycin, azithromycin, or doxycycline that inhibited protein synthesis demonstrated a large reduction of lysed cells with respect to the control, that is, without antibiotics. However, cell lysis prevention was much lower in nonsusceptible strains, with unsuccessful inhibition of protein synthesis. ROC analysis showed that a reduction value of ≥35.6% and ≥40.4% discriminates susceptible and nonsusceptible strains for erythromycin and for doxycycline, respectively, in E. faecalis, whereas ≥20.0% is adequate for both macrolides and doxycycline in S. pneumoniae. Resistant stains were identified in 90-120 min with sensitivity and specificity between 91.7% and 100%. This is a proof of concept that evaluation of the lytic response may be a rapid and efficient test for determination of resistance to antibiotic inhibitors of protein synthesis.

  9. Time-resolved Global and Chromatin Proteomics during Herpes Simplex Virus Type 1 (HSV-1) Infection.

    Science.gov (United States)

    Kulej, Katarzyna; Avgousti, Daphne C; Sidoli, Simone; Herrmann, Christin; Della Fera, Ashley N; Kim, Eui Tae; Garcia, Benjamin A; Weitzman, Matthew D

    2017-04-01

    Herpes simplex virus (HSV-1) lytic infection results in global changes to the host cell proteome and the proteins associated with host chromatin. We present a system level characterization of proteome dynamics during infection by performing a multi-dimensional analysis during HSV-1 lytic infection of human foreskin fibroblast (HFF) cells. Our study includes identification and quantification of the host and viral proteomes, phosphoproteomes, chromatin bound proteomes and post-translational modifications (PTMs) on cellular histones during infection. We analyzed proteomes across six time points of virus infection (0, 3, 6, 9, 12 and 15 h post-infection) and clustered trends in abundance using fuzzy c-means. Globally, we accurately quantified more than 4000 proteins, 200 differently modified histone peptides and 9000 phosphorylation sites on cellular proteins. In addition, we identified 67 viral proteins and quantified 571 phosphorylation events (465 with high confidence site localization) on viral proteins, which is currently the most comprehensive map of HSV-1 phosphoproteome. We investigated chromatin bound proteins by proteomic analysis of the high-salt chromatin fraction and identified 510 proteins that were significantly different in abundance during infection. We found 53 histone marks significantly regulated during virus infection, including a steady increase of histone H3 acetylation (H3K9ac and H3K14ac). Our data provide a resource of unprecedented depth for human and viral proteome dynamics during infection. Collectively, our results indicate that the proteome composition of the chromatin of HFF cells is highly affected during HSV-1 infection, and that phosphorylation events are abundant on viral proteins. We propose that our epi-proteomics approach will prove to be important in the characterization of other model infectious systems that involve changes to chromatin composition. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Effects of Lytic Polysaccharide Monooxygenase Oxidation on Cellulose Structure and Binding of Oxidized Cellulose Oligomers to Cellulases

    Energy Technology Data Exchange (ETDEWEB)

    Vermaas, Josh V.; Crowley, Michael F.; Beckham, Gregg T.; Payne, Christina M.

    2015-05-21

    In nature, polysaccharide glycosidic bonds are cleaved by hydrolytic enzymes for a vast array of biological functions. Recently, a new class of enzymes that utilize an oxidative mechanism to cleave glycosidic linkages was discovered; these enzymes are called lytic polysaccharide monooxygenases (LPMO). These oxidative enzymes are synergistic with cocktails of hydrolytic enzymes and are thought to act primarily on crystalline regions, in turn providing new sites of productive attachment and detachment for processive hydrolytic enzymes. In the case of cellulose, the homopolymer of ..beta..-1,4-d-glucose, enzymatic oxidation occurs at either the reducing end or the nonreducing end of glucose, depending on enzymatic specificity, and results in the generation of oxidized chemical substituents at polymer chain ends. LPMO oxidation of cellulose is thought to produce either a lactone at the reducing end of glucose that can spontaneously or enzymatically convert to aldonic acid or 4-keto-aldose at the nonreducing end that may further oxidize to a geminal diol. Here, we use molecular simulation to examine the effect of oxidation on the structure of crystalline cellulose. The simulations highlight variations in behaviors depending on the chemical identity of the oxidized species and its location within the cellulose fibril, as different oxidized species introduce steric effects that disrupt local crystallinity and in some cases reduce the work needed for polymer decrystallization. Reducing-end oxidations are easiest to decrystallize when located at the end of the fibril, whereas nonreducing end oxidations readily decrystallize from internal cleavage sites despite their lower solvent accessibility. The differential in decrystallization free energy suggests a molecular mechanism consistent with experimentally observed LPMO/cellobiohydrolase synergy. Additionally, the soluble oxidized cellobiose products released by hydrolytic cellulases may bind to the active sites of cellulases

  11. Zebra Alphaherpesviruses (EHV-1 and EHV-9: Genetic Diversity, Latency and Co-Infections

    Directory of Open Access Journals (Sweden)

    Azza Abdelgawad

    2016-09-01

    Full Text Available Alphaherpesviruses are highly prevalent in equine populations and co-infections with more than one of these viruses’ strains frequently diagnosed. Lytic replication and latency with subsequent reactivation, along with new episodes of disease, can be influenced by genetic diversity generated by spontaneous mutation and recombination. Latency enhances virus survival by providing an epidemiological strategy for long-term maintenance of divergent strains in animal populations. The alphaherpesviruses equine herpesvirus 1 (EHV-1 and 9 (EHV-9 have recently been shown to cross species barriers, including a recombinant EHV-1 observed in fatal infections of a polar bear and Asian rhinoceros. Little is known about the latency and genetic diversity of EHV-1 and EHV-9, especially among zoo and wild equids. Here, we report evidence of limited genetic diversity in EHV-9 in zebras, whereas there is substantial genetic variability in EHV-1. We demonstrate that zebras can be lytically and latently infected with both viruses concurrently. Such a co-occurrence of infection in zebras suggests that even relatively slow-evolving viruses such as equine herpesviruses have the potential to diversify rapidly by recombination. This has potential consequences for the diagnosis of these viruses and their management in wild and captive equid populations.

  12. Coccidiomycosis infection of the patella mimicking a neoplasm – two case reports

    International Nuclear Information System (INIS)

    Li, Yi-Chen; Calvert, George; Hanrahan, Christopher J; Jones, Kevin B; Randall, Robert Lor

    2014-01-01

    Coccidioidomycosis is an endemic fungal infection in the southwestern of United States. Most infections are asymptomatic or manifest with mild respiratory complaints. Rare cases may cause extrapulmonary or disseminated disease. We report two cases of knee involvement that presented as isolated lytic lesions of the patella mimicking neoplasms. The first case, a 27 year-old immunocompetent male had progressive left anterior knee pain for four months. The second case was a 78 year-old male had left anterior knee pain for three months. Both of them had visited general physicians without conclusive diagnosis. A low attenuation lytic lesion in the patella was demonstrated on their image studies, and the initial radiologist’s interpretation was suggestive of a primary bony neoplasm. The patients were referred for orthopaedic oncology consultation. The first case had a past episode of pulmonary coccioidomycosis 2 years prior, while the second case had no previous coccioidal infection history but lived in an endemic area, the central valley of California. Surgical biopsy was performed in both cases due to diagnostic uncertainty. Final pathologic examination revealed large thick walled spherules filled with endospores establishing the final diagnosis of extrapulmonary coccidioidomycosis. Though history and laboratory findings are supportive, definitive diagnosis still depends on growth in culture or endospores identified on histology. We suggest that orthopaedic surgeons and radiologists keep in mind that chronic fungal infections can mimic osseous neoplasm by imaging

  13. The CD8 and CD4 T-cell response against Kaposi's sarcoma-associated herpesvirus is skewed towards early and late lytic antigens.

    Directory of Open Access Journals (Sweden)

    Rebecca C Robey

    Full Text Available Kaposi's sarcoma-associated herpesvirus (KSHV is causally related to Kaposi's sarcoma (KS, the most common malignancy in untreated individuals with HIV/AIDS. The adaptive T-cell immune response against KSHV has not been fully characterized. To achieve a better understanding of the antigenic repertoire of the CD8 and CD4 T-cell responses against KSHV, we constructed a library of lentiviral expression vectors each coding for one of 31 individual KSHV open reading frames (ORFs. We used these to transduce monocyte-derived dendritic cells (moDCs isolated from 14 KSHV-seropositive (12 HIV-positive and 7 KSHV-seronegative (4 HIV-positive individuals. moDCs were transduced with up to 3 KSHV ORFs simultaneously (ORFs grouped according to their expression during the viral life cycle. Transduced moDCs naturally process the KSHV genes and present the resulting antigens in the context of MHC class I and II. Transduced moDCs were cultured with purified autologous T cells and the CD8 and CD4 T-cell proliferative responses to each KSHV ORF (or group was assessed using a CFSE dye-based assay. Two pools of early lytic KSHV genes ([ORF8/ORF49/ORF61] and [ORF59/ORF65/K4.1] were frequently-recognized targets of both CD8 and CD4 T cells from KSHV seropositive individuals. One pool of late lytic KSHV genes ([ORF28/ORF36/ORF37] was a frequently-recognized CD8 target and another pool of late genes ([ORF33/K1/K8.1] was a frequently-recognized CD4 target. We report that both the CD8 and CD4 T-cell responses against KSHV are skewed towards genes expressed in the early and late phases of the viral lytic cycle, and identify some previously unknown targets of these responses. This knowledge will be important to future immunological investigations into KSHV and may eventually lead to the development of better immunotherapies for KSHV-related diseases.

  14. The Performance of the Four Anaerobic Blood Culture Bottles BacT/ALERT-FN, -FN Plus, BACTEC-Plus and -Lytic in Detection of Anaerobic Bacteria and Identification by Direct MALDI-TOF MS.

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    Mohammed Almuhayawi

    Full Text Available Detection and identification of anaerobic bacteria in blood cultures (BC is a well-recognized challenge in clinical microbiology. We studied 100 clinical anaerobic BC isolates to evaluate the performance of BacT/ALERT-FN, -FN Plus (BioMérieux, BACTEC-Plus and -Lytic (Becton Dickinson BioSciences BC bottles in detection and time to detection (TTD of anaerobic bacteria. BACTEC Lytic had higher detection rate (94/100, 94% than BacT/ALERT FN Plus (80/100, 80% (p<0.01 in the studied material. There was no significant difference in detection of anaerobic bacteria among the remaining bottle types. The 67 anaerobic bacteria that signalled positive in all four bottle types were analyzed to compare the time to detection (TTD and isolates were directly identified by MALDI-TOF MS. There was a significant difference in TTD among the four bottle types (p<0.0001. The shortest median TTD was 18 h in BACTEC Lytic followed by BacT/ALERT FN (23.5 h, BACTEC Plus (27 h and finally BacT/ALERT FN Plus (38 h bottles. In contrast, MALDI-TOF MS performed similarly in all bottle types with accurate identification in 51/67 (76% BacT/ALERT FN, 51/67 (76% BacT/ALERT FN Plus, 53/67 (79% BACTEC Plus and 50/67 (75% BACTEC Lytic bottles. In conclusion, BACTEC Lytic bottles have significantly better detection rates and shorter TTD compared to the three other bottle types. The anaerobic BC bottles are equally suitable for direct MALDI-TOF MS for rapid and reliable identification of common anaerobic bacteria. Further clinical studies are warranted to investigate the performance of anaerobic BC bottles in detection of anaerobic bacteria and identification by direct MALDI-TOF MS.

  15. Analysis of nanomechanical properties of Borrelia burgdorferi spirochetes under the influence of lytic factors in an in vitro model using atomic force microscopy

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    Małgorzata Tokarska-Rodak

    2015-11-01

    Full Text Available Background: Atomic force microscopy (AFM is an experimental technique which recently has been used in biology, microbiology, and medicine to investigate the topography of surfaces and in the evaluation of mechanical properties of cells. The aim of this study was to evaluate the influence of the complement system and specific anti-Borrelia antibodies in in vitro conditions on the modification of nanomechanical features of B. burgdorferi B31 cells. Material and methods: In order to assess the influence of the complement system and anti-Borrelia antibodies on B. burgdorferi s.s. B31 spirochetes, the bacteria were incubated together with plasma of identified status. The samples were applied on the surface of mica disks. Young’s modulus and adhesive forces were analyzed with a NanoScope V, MultiMode 8 AFM microscope (Bruker by the PeakForce QNM technique in air using NanoScope Analysis 1.40 software (Bruker.Results/Conclusion: The average value of flexibility of spirochetes’ surface expressed by Young’s modulus was 10185.32 MPa, whereas the adhesion force was 3.68 nN. AFM is a modern tool with a broad spectrum of observational and measurement abilities. Young’s modulus and the adhesion force can be treated as parameters in the evaluation of intensity and changes which take place in pathogenic microorganisms under the influence of various lytic factors. The visualization of the changes in association with nanomechanical features provides a realistic portrayal of the lytic abilities of the elements of the innate and adaptive human immune system.

  16. Relationships between molecular structure and kinetic and thermodynamic controls in lipid systems. Part III. Crystallization and phase behavior of 1-palmitoyl-2,3-stearoyl-sn-glycerol (PSS) and tristearoylglycerol (SSS) binary system.

    Science.gov (United States)

    Bouzidi, Laziz; Narine, Suresh S

    2012-01-01

    The phase behavior of 1-palmitoyl-2,3-distearoyl-sn-glycerol (PSS)/tristearoylglycerol (SSS) binary system was investigated in terms of polymorphism, crystallization and melting behavior, microstructure and solid fat content (SFC) using widely different constant cooling rates. Kinetic phase diagrams were experimentally determined from the DSC heating thermograms and analyzed using a thermodynamic model to account for non-ideality of mixing. The kinetic phase diagram presented a typical eutectic behavior with a eutectic point at the 0.5(PSS) mixture with a probable precipitation line from 0.5(PSS) to 1.0(PSS), regardless of the rate at which the sample was cooled. The eutectic temperature decreased only slightly with increasing cooling rate. PSS has a strong effect on the physical properties of the PSS-SSS mixtures. In fact, the overall phase behavior of the PSS-SSS binary system was determined, for a very large part, by the asymmetrical TAG. Moreover, PSS is a key driver of the high stability observed in crystal growth, polymorphism and phase development. Levels as low as 10% PSS, when cooled slowly, and 30% when cooled rapidly, were found to be sufficient to suppress the effect of thermal processing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Nuclear sensing of viral DNA, epigenetic regulation of herpes simplex virus infection, and innate immunity

    International Nuclear Information System (INIS)

    Knipe, David M.

    2015-01-01

    Herpes simplex virus (HSV) undergoes a lytic infection in epithelial cells and a latent infection in neuronal cells, and epigenetic mechanisms play a major role in the differential gene expression under the two conditions. HSV viron DNA is not associated with histones but is rapidly loaded with heterochromatin upon entry into the cell. Viral proteins promote reversal of the epigenetic silencing in epithelial cells while the viral latency-associated transcript promotes additional heterochromatin in neuronal cells. The cellular sensors that initiate the chromatinization of foreign DNA have not been fully defined. IFI16 and cGAS are both essential for innate sensing of HSV DNA, and new evidence shows how they work together to initiate innate signaling. IFI16 also plays a role in the heterochromatinization of HSV DNA, and this review will examine how IFI16 integrates epigenetic regulation and innate sensing of foreign viral DNA to show how these two responses are related. - Highlights: • HSV lytic and latent gene expression is regulated differentially by epigenetic processes. • The sensors of foreign DNA have not been defined fully. • IFI16 and cGAS cooperate to sense viral DNA in HSV-infected cells. • IFI16 plays a role in both innate sensing of HSV DNA and in restricting its expression

  18. Nuclear sensing of viral DNA, epigenetic regulation of herpes simplex virus infection, and innate immunity

    Energy Technology Data Exchange (ETDEWEB)

    Knipe, David M., E-mail: david_knipe@hms.harvard.edu

    2015-05-15

    Herpes simplex virus (HSV) undergoes a lytic infection in epithelial cells and a latent infection in neuronal cells, and epigenetic mechanisms play a major role in the differential gene expression under the two conditions. HSV viron DNA is not associated with histones but is rapidly loaded with heterochromatin upon entry into the cell. Viral proteins promote reversal of the epigenetic silencing in epithelial cells while the viral latency-associated transcript promotes additional heterochromatin in neuronal cells. The cellular sensors that initiate the chromatinization of foreign DNA have not been fully defined. IFI16 and cGAS are both essential for innate sensing of HSV DNA, and new evidence shows how they work together to initiate innate signaling. IFI16 also plays a role in the heterochromatinization of HSV DNA, and this review will examine how IFI16 integrates epigenetic regulation and innate sensing of foreign viral DNA to show how these two responses are related. - Highlights: • HSV lytic and latent gene expression is regulated differentially by epigenetic processes. • The sensors of foreign DNA have not been defined fully. • IFI16 and cGAS cooperate to sense viral DNA in HSV-infected cells. • IFI16 plays a role in both innate sensing of HSV DNA and in restricting its expression.

  19. EBV infection is common in gingival epithelial cells of the periodontium and worsens during chronic periodontitis.

    Directory of Open Access Journals (Sweden)

    Séverine Vincent-Bugnas

    Full Text Available An amplifying role for oral epithelial cells (ECs in Epstein-Barr Virus (EBV infection has been postulated to explain oral viral shedding. However, while lytic or latent EBV infections of oro/nasopharyngeal ECs are commonly detected under pathological conditions, detection of EBV-infected ECs in healthy conditions is very rare. In this study, a simple non-surgical tissue sampling procedure was used to investigate EBV infection in the periodontal epithelium that surrounds and attaches teeth to the gingiva. Surprisingly, we observed that the gingival ECs of the periodontium (pECs are commonly infected with EBV and may serve as an important oral reservoir of latently EBV-infected cells. We also found that the basal level of epithelial EBV-infection is significantly increased in chronic periodontitis, a common inflammatory disease that undermines the integrity of tooth-supporting tissues. Moreover, the level of EBV infection was found to correlate with disease severity. In inflamed tissues, EBV-infected pECs appear to be prone to apoptosis and to produce larger amounts of CCL20, a pivotal inflammatory chemokine that controls tissue infiltration by immune cells. Our discovery that the periodontal epithelium is a major site of latent EBV infection sheds a new light on EBV persistence in healthy carriers and on the role of this ubiquitous virus in periodontitis. Moreover, the identification of this easily accessible site of latent infection may encourage new approaches to investigate and monitor other EBV-associated disorders.

  20. Bioactive activities of natural products against herpesvirus infection.

    Science.gov (United States)

    Son, Myoungki; Lee, Minjung; Sung, Gi-Ho; Lee, Taeho; Shin, Yu Su; Cho, Hyosun; Lieberman, Paul M; Kang, Hyojeung

    2013-10-01

    More than 90% of adults have been infected with at least one human herpesvirus, which establish long-term latent infection for the life of the host. While anti-viral drugs exist that limit herpesvirus replication, many of these are ineffective against latent infection. Moreover, drug-resistant strains of herpesvirus emerge following chemotherapeutic treatment. For example, resistance to acyclovir and related nucleoside analogues can occur when mutations arise in either HSV thymidine kinase or DNA polymerases. Thus, there exists an unmet medical need to develop new anti-herpesvirus agents with different mechanisms of action. In this Review, we discuss the promise of anti-herpetic substances derived from natural products including extracts and pure compounds from potential herbal medicines. One example is Glycyrrhizic acid isolated from licorice that shows promising antiviral activity towards human gammaherpesviruses. Secondly, we discuss anti-herpetic mechanisms utilized by several natural products in molecular level. While nucleoside analogues inhibit replicating herpesviruses in lytic replication, some natural products can disrupt the herpesvirus latent infection in the host cell. In addition, natural products can stimulate immune responses against herpesviral infection. These findings suggest that natural products could be one of the best choices for development of new treatments for latent herpesvirus infection, and may provide synergistic anti-viral activity when supplemented with nucleoside analogues. Therefore, it is important to identify which natural products are more efficacious anti-herpetic agents, and to understand the molecular mechanism in detail for further advance in the anti-viral therapies.

  1. Pinworm Infection

    Science.gov (United States)

    Pinworm infection Overview Pinworm infection is the most common type of intestinal worm infection in the United States and one of the most common worldwide. Pinworms are thin and white, measuring about 1/4 ...

  2. HHV-8 infection in patients with AIDS-related Kaposi's sarcoma in Brazil

    Directory of Open Access Journals (Sweden)

    Keller R.

    2001-01-01

    Full Text Available The aims of the present study were to determine the prevalence of human herpesvirus type 8 (HHV-8 in HIV-positive Brazilian patients with (HIV+/KS+ and without Kaposi's sarcoma (HIV+/KS- using PCR and immunofluorescence assays, to assess its association with KS disease, to evaluate the performance of these tests in detecting HHV-8 infection, and to investigate the association between anti-HHV-8 antibody titers, CD4 counts and staging of KS disease. Blood samples from 66 patients, 39 HIV+/KS+ and 27 HIV+/KS-, were analyzed for HHV-8 viremia in peripheral blood mononuclear cells by PCR and HHV-8 antigenemia for latent and lytic infection by immunofluorescence assay. Positive samples for latent nuclear HHV-8 antigen (LNA antibodies were titrated out from 1/100 to 1/409,600 dilution. Clinical information was collected from medical records and risk behavior was assessed through an interview. HHV-8 DNA sequences were detected by PCR in 74.3% of KS+ patients and in 3.7% of KS- patients. Serological assays were similar in detecting anti-LNA antibodies and anti-lytic antigens in sera from KS+ patients (79.5% and KS- patients (18.5%. HHV-8 was associated with KS whatever the method used, i.e., PCR (odds ratio (OR = 7.4, 95% confidence interval (CI = 2.16-25.61 or anti-LNA and anti-lytic antibodies (OR = 17.0, 95%CI = 4.91-59.14. Among KS+ patients, HHV-8 titration levels correlated positively with CD4 counts (rho 0.48, P = 0.02, but not with KS staging. HHV-8 is involved in the development of KS in different geographic areas worldwide, as it is in Brazil, where HHV-8 is more frequent among HIV+ patients. KS severity was associated with immunodeficiency, but no correlation was found between HHV-8 antibody titers and KS staging.

  3. Transcriptome Analysis of a Bloom-Forming Cyanobacterium Microcystis aeruginosa during Ma-LMM01 Phage Infection

    Directory of Open Access Journals (Sweden)

    Daichi Morimoto

    2018-01-01

    Full Text Available Microcystis aeruginosa forms massive blooms in eutrophic freshwaters, where it is constantly exposed to lytic cyanophages. Unlike other marine cyanobacteria, M. aeruginosa possess remarkably abundant and diverse potential antiviral defense genes. Interestingly, T4-like cyanophage Ma-LMM01, which is the sole cultured lytic cyanophage infecting M. aeruginosa, lacks the host-derived genes involved in maintaining host photosynthesis and directing host metabolism that are abundant in other marine cyanophages. Based on genomic comparisons with closely related cyanobacteria and their phages, Ma-LMM01 is predicted to employ a novel infection program that differs from that of other marine cyanophages. Here, we used RNA-seq technology and in silico analysis to examine transcriptional dynamics during Ma-LMM01 infection to reveal host transcriptional responses to phage infection, and to elucidate the infection program used by Ma-LMM01 to avoid the highly abundant host defense systems. Phage-derived reads increased only slightly at 1 h post-infection, but significantly increased from 16% of total cellular reads at 3 h post-infection to 33% of all reads by 6 h post-infection. Strikingly, almost none of the host genes (0.17% showed a significant change in expression during infection. However, like other lytic dsDNA phages, including marine cyanophages, phage gene dynamics revealed three expression classes: early (host-takeover, middle (replication, and late (virion morphogenesis. The early genes were concentrated in a single ∼5.8-kb window spanning 10 open reading frames (gp054–gp063 on the phage genome. None of the early genes showed homology to the early genes of other T4-like phages, including known marine cyanophages. Bacterial RNA polymerase (σ70 recognition sequences were also found in the upstream region of middle and late genes, whereas phage-specific motifs were not found. Our findings suggest that unlike other known T4-like phages, Ma-LMM01

  4. A novel solid self-nanoemulsifying drug delivery system (S-SNEDDS) for improved stability and oral bioavailability of an oily drug, 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol.

    Science.gov (United States)

    Kim, Kyeong Soo; Yang, Eun Su; Kim, Dong Shik; Kim, Dong Wuk; Yoo, Hye Hyun; Yong, Chul Soon; Youn, Yu Seok; Oh, Kyung Taek; Jee, Jun-Pil; Kim, Jong Oh; Jin, Sung Giu; Choi, Han Gon

    2017-11-01

    To develop a novel solid self-nanoemulsifying drug delivery system (S-SNEDDS) for a water-insoluble oily drug, 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) with improved stability and oral bioavailability, numerous S-SNEDDS were prepared with surfactant, hydrophilic polymer, antioxidant, and calcium silicate (porous carrier) using the spray-drying method. Their physicochemical properties were evaluated using emulsion droplet size analysis, SEM and PXRD. Moreover, the solubility, dissolution, stability, and pharmacokinetics of the selected S-SNEDDS were assessed compared with the drug and a commercial soft capsule. Sodium lauryl sulfate (SLS) and hydroxypropyl methylcellulose (HPMC) with the highest drug solubility were selected as surfactant and hydrophilic polymer, respectively. Among the antioxidants tested, only butylated hydroxyanisole (BHA) could completely protect the drug from oxidative degradation. The S-SNEDDS composed of PLAG/SLS/HPMC/BHA/calcium silicate at a weight ratio of 1: 0.25: 0.1: 0.0002: 0.5 provided an emulsion droplet size of less than 300 nm. In this S-SNEDDS, the drug and other ingredients might exist in the pores of carrier and attach onto its surface. It considerably improved the drug stability (about 100 vs. 70%, 60 °C for 5 d) and dissolution (about 80 vs. 20% in 60 min) compared to the commercial soft capsule. Moreover, the S-SNEDDS gave higher AUC, C max , and T max values than the commercial soft capsule; in particular, the former improved the oral bioavailability of PLAG by about 3-fold. Our results suggested that this S-SNEDDS provided excellent stability and oral bioavailability of PLAG. Thus, this S-SNEDDS would be recommended as a powerful oral drug delivery system for an oily drug, PLAG.

  5. Exo-exo synergy between Cel6A and Cel7A from Hypocrea jecorina: Role of carbohydrate binding module and the endo-lytic character of the enzymes.

    Science.gov (United States)

    Badino, Silke F; Christensen, Stefan J; Kari, Jeppe; Windahl, Michael S; Hvidt, Søren; Borch, Kim; Westh, Peter

    2017-08-01

    Synergy between cellulolytic enzymes is essential in both natural and industrial breakdown of biomass. In addition to synergy between endo- and exo-lytic enzymes, a lesser known but equally conspicuous synergy occurs among exo-acting, processive cellobiohydrolases (CBHs) such as Cel7A and Cel6A from Hypocrea jecorina. We studied this system using microcrystalline cellulose as substrate and found a degree of synergy between 1.3 and 2.2 depending on the experimental conditions. Synergy between enzyme variants without the carbohydrate binding module (CBM) and its linker was strongly reduced compared to the wild types. One plausible interpretation of this is that exo-exo synergy depends on the targeting role of the CBM. Many earlier works have proposed that exo-exo synergy was caused by an auxiliary endo-lytic activity of Cel6A. However, biochemical data from different assays suggested that the endo-lytic activity of both Cel6A and Cel7A were 10 3 -10 4 times lower than the common endoglucanase, Cel7B, from the same organism. Moreover, the endo-lytic activity of Cel7A was 2-3-fold higher than for Cel6A, and we suggest that endo-like activity of Cel6A cannot be the main cause for the observed synergy. Rather, we suggest the exo-exo synergy found here depends on different specificities of the enzymes possibly governed by their CBMs. Biotechnol. Bioeng. 2017;114: 1639-1647. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Deficient incorporation of spike protein into virions contributes to the lack of infectivity following establishment of a persistent, non-productive infection in oligodendroglial cell culture by murine coronavirus

    International Nuclear Information System (INIS)

    Liu Yin; Herbst, Werner; Cao Jianzhong; Zhang Xuming

    2011-01-01

    Infection of mouse oligodendrocytes with a recombinant mouse hepatitis virus (MHV) expressing a green fluorescence protein facilitated specific selection of virus-infected cells and subsequent establishment of persistence. Interestingly, while viral genomic RNAs persisted in infected cells over 14 subsequent passages with concomitant synthesis of viral subgenomic mRNAs and structural proteins, no infectious virus was isolated beyond passage 2. Further biochemical and electron microscopic analyses revealed that virions, while assembled, contained little spike in the envelope, indicating that lack of infectivity during persistence was likely due to deficiency in spike incorporation. This type of non-lytic, non-productive persistence in oligodendrocytes is unique among animal viruses and resembles MHV persistence previously observed in the mouse central nervous system. Thus, establishment of such a culture system that can recapitulate the in vivo phenomenon will provide a powerful approach for elucidating the mechanisms of coronavirus persistence in glial cells at the cellular and molecular levels.

  7. The homeostasis of Plasmodium falciparum-infected red blood cells.

    Directory of Open Access Journals (Sweden)

    Jakob M A Mauritz

    2009-04-01

    Full Text Available The asexual reproduction cycle of Plasmodium falciparum, the parasite responsible for severe malaria, occurs within red blood cells. A merozoite invades a red cell in the circulation, develops and multiplies, and after about 48 hours ruptures the host cell, releasing 15-32 merozoites ready to invade new red blood cells. During this cycle, the parasite increases the host cell permeability so much that when similar permeabilization was simulated on uninfected red cells, lysis occurred before approximately 48 h. So how could infected cells, with a growing parasite inside, prevent lysis before the parasite has completed its developmental cycle? A mathematical model of the homeostasis of infected red cells suggested that it is the wasteful consumption of host cell hemoglobin that prevents early lysis by the progressive reduction in the colloid-osmotic pressure within the host (the colloid-osmotic hypothesis. However, two critical model predictions, that infected cells would swell to near prelytic sphericity and that the hemoglobin concentration would become progressively reduced, remained controversial. In this paper, we are able for the first time to correlate model predictions with recent experimental data in the literature and explore the fine details of the homeostasis of infected red blood cells during five model-defined periods of parasite development. The conclusions suggest that infected red cells do reach proximity to lytic rupture regardless of their actual volume, thus requiring a progressive reduction in their hemoglobin concentration to prevent premature lysis.

  8. Genomic library screening for viruses from the human dental plaque revealed pathogen-specific lytic phage sequences.

    Science.gov (United States)

    Al-Jarbou, Ahmed Nasser

    2012-01-01

    Bacterial pathogenesis presents an astounding arsenal of virulence factors that allow them to conquer many different niches throughout the course of infection. Principally fascinating is the fact that some bacterial species are able to induce different diseases by expression of different combinations of virulence factors. Nevertheless, studies aiming at screening for the presence of bacteriophages in humans have been limited. Such screening procedures would eventually lead to identification of phage-encoded properties that impart increased bacterial fitness and/or virulence in a particular niche, and hence, would potentially be used to reverse the course of bacterial infections. As the human oral cavity represents a rich and dynamic ecosystem for several upper respiratory tract pathogens. However, little is known about virus diversity in human dental plaque which is an important reservoir. We applied the culture-independent approach to characterize virus diversity in human dental plaque making a library from a virus DNA fraction amplified using a multiple displacement method and sequenced 80 clones. The resulting sequence showed 44% significant identities to GenBank databases by TBLASTX analysis. TBLAST homology comparisons showed that 66% was viral; 18% eukarya; 10% bacterial; 6% mobile elements. These sequences were sorted into 6 contigs and 45 single sequences in which 4 contigs and a single sequence showed significant identity to a small region of a putative prophage in the Corynebacterium diphtheria genome. These findings interestingly highlight the uniqueness of over half of the sequences, whilst the dominance of a pathogen-specific prophage sequences imply their role in virulence.

  9. Technological application of an extracellular cell lytic enzyme in xanthan gum clarification Aplicação tecnológica de uma enzima celulolítica para clarificação de goma xantana

    Directory of Open Access Journals (Sweden)

    Suresh Shastry

    2005-03-01

    Full Text Available An extracellular cell lytic enzyme from Pseudomonas sp. was active on heat killed cells of Xanthomonas campestris. The lytic activity caused enzymatic digestion of X.campestris xanthan gum. Digestion was effective for highly viscous native xanthan 2.0% (w/v and 2.5% (w/v commercial Sigma xanthan. Scanning electron microscopy and SDS-PAGE observations confirmed the cell lytic action on X.campestris cells.Uma enzima extracelular celulolítica produzida por Pseudomonas sp. foi ativa sobre células de Xanthomonas campestris mortas pelo calor. A atividade lítica causou a digestão enzimática de goma xantana de X. campestris. A digestão foi eficiente tanto para xantana nativa altamante viscosa (2,0% w/v como para xantana comercial Sigma (2,5% w/v. Observações por microscopia eletrônica de varredura demonstraram a ação celulolítica sobre células de X. campestris.

  10. Lytic process studies on anaerobic digestion of organic wastes. Etude des activites lytiques intervenant au cours de la digestion anaerobie des dechets organiques; Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Durecu, S.; Thauront, J. (PEC Engineering, 95 - Cergy Pontoise (France). Service de Recherche et Developpement); Festino, C.; Aubart, C.; Reisinger, O. (Nancy-1 Univ., 54 - Vandoeuvre-les-Nancy (France). Lab. d' Ecologie Microbienne)

    1990-01-01

    To improve anaerobic digestion of pig manure, solubilization of the solid fraction was studied as the rate limiting step in the biomethanation process in an experimental completely mixed digester. The performance of conventional digesters should anaerobic microflora were inefficient in degrading complex biopolymers such as plant fibers. For pectin or cellulose, the use of digestible co-substrates accelerated methanation by increasing the yield of methane and a doubling of the apparent first order solubilization rate constant (Kp = 0.090/d). Lignin should methanation by decreasing methane yield and reducing the rate constant (Kp = 0.035/d). This inhibition was unrelated to volatile fatty acid accumulation. Nine strains of pectinolytic and/or cellulolytic bacteria were isolated. Chitin, a structural constituent of many final species, was effectively solubilized dining anaerobic digestion of pig manure. Seven strains of chitinolytic bacteria were isolated by high chitnese activity. The mycolytic power of fermenting manure processes acting through lytic microflora has been shown to be an effective antagonist of soil borne phytopathogenic fungi, as well as a fertilizer. In greenhouse trails, this compiled fraction demonstrated its ability to control flux unit. Keratin enhanced methane production, and increased H{sub 2}S nearly six-fold. Bacterial strains able to solubilize keratin were also used in autoclawed feather meal to extract the amino acids. (KJD)

  11. Crystallization of a fungal lytic polysaccharide monooxygenase expressed from glycoengineered Pichia pastoris for X-ray and neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    O; Dell, William B.; Swartz, Paul D.; Weiss, Kevin L.; Meilleur, Flora (ORNL); (NCSU)

    2017-01-19

    Lytic polysaccharide monooxygenases (LPMOs) are carbohydrate-disrupting enzymes secreted by bacteria and fungi that break glycosidic bondsviaan oxidative mechanism. Fungal LPMOs typically act on cellulose and can enhance the efficiency of cellulose-hydrolyzing enzymes that release soluble sugars for bioethanol production or other industrial uses. The enzyme PMO-2 fromNeurospora crassa(NcPMO-2) was heterologously expressed inPichia pastoristo facilitate crystallographic studies of the fungal LPMO mechanism. Diffraction resolution and crystal morphology were improved by expressingNcPMO-2 from a glycoengineered strain ofP. pastorisand by the use of crystal seeding methods, respectively. These improvements resulted in high-resolution (1.20 Å) X-ray diffraction data collection at 100 K and the production of a largeNcPMO-2 crystal suitable for room-temperature neutron diffraction data collection to 2.12 Å resolution.

  12. Biocontrol ability of Lysobacter antibioticus HS124 against Phytophthora blight is mediated by the production of 4-hydroxyphenylacetic acid and several lytic enzymes.

    Science.gov (United States)

    Ko, Hyun-Sun; Jin, Rong-De; Krishnan, Hari B; Lee, Sang-Bog; Kim, Kil-Yong

    2009-12-01

    Several rhizobacteria play a vital role in plant protection, plant growth promotion and the improvement of soil health. In this study, we have isolated a strain of Lysobacter antibioticus HS124 from rhizosphere and demonstrate its antifungal activity against various pathogens including Phytophthora capsici, a destructive pathogen of pepper plants. L. antibioticus HS124 produced lytic enzymes such as chitinase, beta-1,3-glucanase, lipase, protease, and an antibiotic compound. This antibiotic compound was purified by diaion HP-20, silica gel, sephadex LH-20 column chromatography and high performance liquid chromatography. The purified compound was identified as 4-hydroxyphenylacetic acid by gas chromatography-electron ionization (GC-EI) and gas chromatography-chemical ionization (GC-CI) mass spectrometry. This antibiotic exhibited destructive activity toward P. capsici hyphae. In vivo experiments utilizing green house grown pepper plants demonstrated the protective effect of L. antibioticus HS124 against P. capsici. The growth of pepper plants treated with L. antibioticus culture was enhanced, resulting in greater protection from fungal disease. Optimum growth and protection was found when cultures were grown in presence of Fe(III). Additionally, the activities of pathogenesis-related proteins such as chitinase and beta-1,3-glucanase decreased in roots, but increased in leaves with time after treatment compared to controls. Our results demonstrate L. antibioticus HS124 as a promising candidate for biocontrol of P. capsici in pepper plants.

  13. Mathematical Modeling Predicts that Increased HSV-2 Shedding in HIV-1 Infected Persons Is Due to Poor Immunologic Control in Ganglia and Genital Mucosa.

    Directory of Open Access Journals (Sweden)

    Joshua T Schiffer

    Full Text Available A signature feature of HIV infection is poor control of herpes virus infections, which reactivate from latency and cause opportunistic infections. While the general mechanism underlying this observation is deficient CD4+T-cell function, it is unknown whether increased severity of herpes virus infections is due primarily to poor immune control in latent or lytic sites of infection, or whether CD4+ immunodeficiency leads to more critical downstream deficits in humoral or cell-mediated immunologic responses. Here we compare genital shedding patterns of herpes simplex virus-2 (HSV-2 in 98 HIV infected and 98 HIV uninfected men matched on length of infection, HSV-1 serostatus and nationality. We demonstrate that high copy HSV-2 shedding is more frequent in HIV positive men, particularly in participants with CD4+ T-cell count <200/μL. Genital shedding is more frequent due to higher rate of shedding episodes, as well as a higher proportion of prolonged shedding episodes. Peak episode viral load was not found to differ between HIV infected and uninfected participants regardless of CD4+ T-cell count. We simulate a mathematical model which recapitulates these findings and identifies that rate of HSV-2 release from neural tissue increases, duration of mucosal cytolytic immune protection decreases, and cell-free viral lifespan increases in HIV infected participants. These results suggest that increased HSV-2 shedding in HIV infected persons may be caused by impaired immune function in both latent and lytic tissue compartments, with deficits in clearance of HSV-2 infected cells and extracellular virus.

  14. Lytic cell death induced by melittin bypasses pyroptosis but induces NLRP3 inflammasome activation and IL-1β release.

    Science.gov (United States)

    Martín-Sánchez, Fátima; Martínez-García, Juan José; Muñoz-García, María; Martínez-Villanueva, Miriam; Noguera-Velasco, José A; Andreu, David; Rivas, Luís; Pelegrín, Pablo

    2017-08-10

    The nucleotide-binding domain and leucine-rich repeat-containing receptor with a pyrin domain 3 (NLRP3) inflammasome is a sensor for different types of infections and alterations of homeostatic parameters, including abnormally high levels of the extracellular nucleotide ATP or crystallization of different metabolites. All NLRP3 activators trigger a similar intracellular pathway, where a decrease in intracellular K + concentration and permeabilization of plasma membrane are key steps. Cationic amphipathic antimicrobial peptides and peptide toxins permeabilize the plasma membrane. In fact, some of them have been described to activate the NLRP3 inflammasome. Among them, the bee venom antimicrobial toxin peptide melittin is known to elicit an inflammatory reaction via the NLRP3 inflammasome in response to bee venom. Our study found that melittin induces canonical NLRP3 inflammasome activation by plasma membrane permeabilization and a reduction in the intracellular K + concentration. Following melittin treatment, the apoptosis-associated speck-like protein, an adaptor protein with a caspase recruitment domain (ASC), was necessary to activate caspase-1 and induce IL-1β release. However, cell death induced by melittin prevented the formation of large ASC aggregates, amplification of caspase-1 activation, IL-18 release and execution of pyroptosis. Therefore, melittin-induced activation of the NLRP3 inflammasome results in an attenuated inflammasome response that does not result in caspase-1 dependent cell death.

  15. Productively infected murine Kaposi's sarcoma-like tumors define new animal models for studying and targeting KSHV oncogenesis and replication.

    Directory of Open Access Journals (Sweden)

    Brittany M Ashlock

    Full Text Available Kaposi's sarcoma (KS is an AIDS-defining cancer caused by the KS-associated herpesvirus (KSHV. KS tumors are composed of KSHV-infected spindle cells of vascular origin with aberrant neovascularization and erythrocyte extravasation. KSHV genes expressed during both latent and lytic replicative cycles play important roles in viral oncogenesis. Animal models able to recapitulate both viral and host biological characteristics of KS are needed to elucidate oncogenic mechanisms, for developing targeted therapies, and to trace cellular components of KS ontogeny. Herein, we describe two new murine models of Kaposi's sarcoma. We found that murine bone marrow-derived cells, whether established in culture or isolated from fresh murine bone marrow, were infectable with rKSHV.219, formed KS-like tumors in immunocompromised mice and produced mature herpesvirus-like virions in vivo. Further, we show in vivo that the histone deacetylase (HDAC inhibitor suberoylanilide hydroxamic acid (SAHA/Vorinostat enhanced viral lytic reactivation. We propose that these novel models are ideal for studying both viral and host contributions to KSHV-induced oncogenesis as well as for testing virally-targeted antitumor strategies for the treatment of Kaposi's sarcoma. Furthermore, our isolation of bone marrow-derived cell populations containing a cell type that, when infected with KSHV, renders a tumorigenic KS-like spindle cell, should facilitate systematic identification of KS progenitor cells.

  16. Infective Endocarditis

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Infective Endocarditis Updated:Mar 29,2018 View an illustration of endocarditis Infective ... procedure. Web Booklets on Congenital Heart Defects These online publications describe many defects and the procedures used ...

  17. MRSA Infection

    Science.gov (United States)

    ... to spread and sometimes become life-threatening. MRSA infections may affect your: Bloodstream Lungs Heart Bones Joints Prevention Preventing HA-MRSA In the hospital, people who are infected or colonized with MRSA ...

  18. Campylobacter Infections

    Science.gov (United States)

    Campylobacter infection is a common foodborne illness. You usually get it from eating contaminated food, especially raw ... You can also get it from drinking contaminated water or raw milk, or handling infected animal feces ( ...

  19. Staph Infections

    Science.gov (United States)

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... infection. People with skin problems like burns or eczema may be more likely to get staph skin ...

  20. Rotavirus Infections

    Science.gov (United States)

    Rotavirus is a virus that causes gastroenteritis. Symptoms include severe diarrhea, vomiting, fever, and dehydration. Almost all ... the U.S. are likely to be infected with rotavirus before their 5th birthday. Infections happen most often ...

  1. Shigella Infections

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Shigella Infections KidsHealth / For Parents / Shigella Infections What's in ... Doctor Print en español Infecciones por Shigella About Shigella Shigella are bacteria that can infect the digestive ...

  2. UV irradiation of Shigella Dysenteriae induced the transformation and excision of a presumed integrated lysogenic prophage Shd-4L10 into a lytic phase

    International Nuclear Information System (INIS)

    Rodrigues, F. K.; Addy, B.; Armah, G.; Fobil, J.; Steiner-Asiedu, M.; Efavi, J.

    2012-01-01

    Repeated exposures of Shigella dysenteriae strain A to ultra-violet radiation (253.7 nm) with intervening outgrowth of survivors gave rise to clear bacteriophage plaques. Isolation, propagation and partial purification of the new Shd-4LI0 phages showed that they are similar in morphology to the Myxobacteriaphage Mx-4 described earlier. The new phages retained the general characteristics of S. dystenteriae phageShd-4L3, including serological properties and phage typing. It is suggested that ultra-violet irradiation may have played a role in the transformation and excision of the presumed lysogen of S. dysenteriaestrain A into a lytic phase. PhageShd-4LI0 was subsequently partially characterized. It has a density of 1.61, a DNA: protein ratio of 0.42 and thus a cryptogram of D/2:54.3/32.5:X/X: B/O. The phage was further characterised by fractionation of its protein using SDS-polyacrilamide gel electrophoresis. DNA extracted from phages was hydrolysed with restriction endonuclease R., EcoR1. The restriction fragments were catalogued and their apparent molecular weights calculated from electrophoresis gels calibrated with fragments from DNA of coliphageλ λ. From the total fragments obtained with nuclease R., EcoR1, the apparent minimum molecular weight of phage Shd-4LI0DNA was found to be 54.3 x 10 6 Daltons. The molecular weight of the phage DNA was also calculated from measurements of contour length of purified DNA samples, using the formula MW = 1.97 x 10 10 1/(magnification), where 1 is the measured length of DNA in centimetres). The very close relatedness with phage Shd-4L3 was confirmed by these techniques. (au)

  3. Structural and molecular dynamics studies of a C1-oxidizing lytic polysaccharide monooxygenase from Heterobasidion irregulare reveal amino acids important for substrate recognition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing [Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala Sweden; Kognole, Abhishek A. [Department of Chemical and Materials Engineering, University of Kentucky, Lexington KY USA; Wu, Miao [Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala Sweden; Westereng, Bjørge [Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, Ås Norway; Crowley, Michael F. [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Kim, Seonah [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Dimarogona, Maria [Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala Sweden; Department of Chemical Engineering, University of Patras, Greece; Payne, Christina M. [Department of Chemical and Materials Engineering, University of Kentucky, Lexington KY USA; Directorate of Engineering, Division of Chemical, Bioengineering, Environmental, and Transport Systems, National Science Foundation, Alexandria VA USA; Sandgren, Mats [Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala Sweden

    2018-04-24

    Lytic polysaccharide monooxygenases (LPMOs) are a group of recently discovered enzymes that play important roles in the decomposition of recalcitrant polysaccharides. Here, we report the biochemical, structural, and computational characterization of an LPMO from the white-rot fungus Heterobasidion irregulare (HiLPMO9B). This enzyme oxidizes cellulose at the C1 carbon of glycosidic linkages. The crystal structure of HiLPMO9B was determined at 2.1 A resolution using X-ray crystallography. Unlike the majority of the currently available C1-specific LPMO structures, the HiLPMO9B structure contains an extended L2 loop, connecting ..beta..-strands ..beta..2 and ..beta..3 of the ..beta..-sandwich structure. Molecular dynamics (MD) simulations suggest roles for both aromatic and acidic residues in the substrate binding of HiLPMO9B, with the main contribution from the residues located on the extended region of the L2 loop (Tyr20) and the LC loop (Asp205, Tyr207, and Glu210). Asp205 and Glu210 were found to be involved in the hydrogen bonding with the hydroxyl group of the C6 carbon of glucose moieties directly or via a water molecule. Two different binding orientations were observed over the course of the MD simulations. In each orientation, the active-site copper of this LPMO preferentially skewed toward the pyranose C1 of the glycosidic linkage over the targeted glycosidic bond. This study provides additional insight into cellulose binding by C1-specific LPMOs, giving a molecular-level picture of active site substrate interactions.

  4. Fighting Viral Infections and Virus-Driven Tumors with Cytotoxic CD4+ T Cells

    Science.gov (United States)

    Muraro, Elena; Merlo, Anna; Martorelli, Debora; Cangemi, Michela; Dalla Santa, Silvia; Dolcetti, Riccardo; Rosato, Antonio

    2017-01-01

    CD4+ T cells have been and are still largely regarded as the orchestrators of immune responses, being able to differentiate into distinct T helper cell populations based on differentiation signals, transcription factor expression, cytokine secretion, and specific functions. Nonetheless, a growing body of evidence indicates that CD4+ T cells can also exert a direct effector activity, which depends on intrinsic cytotoxic properties acquired and carried out along with the evolution of several pathogenic infections. The relevant role of CD4+ T cell lytic features in the control of such infectious conditions also leads to their exploitation as a new immunotherapeutic approach. This review aims at summarizing currently available data about functional and therapeutic relevance of cytotoxic CD4+ T cells in the context of viral infections and virus-driven tumors. PMID:28289418

  5. Infection and upregulation of proinflammatory cytokines in human brain vascular pericytes by human cytomegalovirus

    Directory of Open Access Journals (Sweden)

    Alcendor Donald J

    2012-05-01

    Full Text Available Abstract Background Congenital human cytomegalovirus (HCMV infections can result in CNS abnormalities in newborn babies including vision loss, mental retardation, motor deficits, seizures, and hearing loss. Brain pericytes play an essential role in the development and function of the blood–brain barrier yet their unique role in HCMV dissemination and neuropathlogy has not been reported. Methods Primary human brain vascular pericytes were exposed to a primary clinical isolate of HCMV designated ‘SBCMV’. Infectivity was analyzed by microscopy, immunofluorescence, Western blot, and qRT-PCR. Microarrays were performed to identify proinflammatory cytokines upregulated after SBCMV exposure, and the results validated by real-time quantitative polymerase chain reaction (qPCR methodology. In situ cytokine expression of pericytes after exposure to HCMV was examined by ELISA and in vivo evidence of HCMV infection of brain pericytes was shown by dual-labeled immunohistochemistry. Results HCMV-infected human brain vascular pericytes as evidenced by several markers. Using a clinical isolate of HCMV (SBCMV, microscopy of infected pericytes showed virion production and typical cytomegalic cytopathology. This finding was confirmed by the expression of major immediate early and late virion proteins and by the presence of HCMV mRNA. Brain pericytes were fully permissive for CMV lytic replication after 72 to 96 hours in culture compared to human astrocytes or human brain microvascular endothelial cells (BMVEC. However, temporal transcriptional expression of pp65 virion protein after SBCMV infection was lower than that seen with the HCMV Towne laboratory strain. Using RT-PCR and dual-labeled immunofluorescence, proinflammatory cytokines CXCL8/IL-8, CXCL11/ITAC, and CCL5/Rantes were upregulated in SBCMV-infected cells, as were tumor necrosis factor-alpha (TNF-alpha, interleukin-1 beta (IL-1beta, and interleukin-6 (IL-6. Pericytes exposed to SBCMV elicited

  6. Unusually severe cases of Kingella kingae osteoarticular infections in children.

    Science.gov (United States)

    Mallet, Cindy; Ceroni, Dimitri; Litzelmann, Estelle; Dubois-Ferriere, Victor; Lorrot, Mathie; Bonacorsi, Stéphane; Mazda, Keyvan; Ilharreborde, Brice

    2014-01-01

    With the development of molecular biology and specific polymerase chain reaction, Kingella kingae has become the primary diagnosis of osteoarticular infections in young children. Clinical features of these osteoarticular infections are typically mild, and outcome is almost always favorable. We report a series of unusually severe cases of K. kingae osteoarticular infections. All patients with severe osteoarticular infections at presentation were reviewed retrospectively in 2 European pediatric centers. K. kingae was identified using real-time polymerase chain reaction in blood, fluid joint or osseous samples. Clinical, laboratory tests and radiographic data during hospitalization and follow-up were analyzed. Ten children (mean age 21 ± 12 months) with severe osteoarticular infections caused by K. kingae were identified between 2008 and 2011. Diagnostic delay averaged 13.2 ± 8 days. Only 1 patient was febrile at admission, and 50% children had normal C-reactive protein values (≤10 mg/dL) at presentation. Surgical treatment was performed in all cases. Intravenous antibiotic therapy by cephalosporins for an average of 8 ± 6 days was followed by oral treatment for 27 ± 6 days. Mean follow-up was 24.8 ± 9 months, and satisfactory outcomes were reported in all cases. Two patients (20%) developed a central epiphysiodesis of the proximal humerus during follow-up, but without significant clinical consequence for the moment. Because of their mild clinical features at onset, diagnosis of K. kingae osteoarticular infections can be delayed. Care should be taken for early detection and treatment of these infections because bony lytic lesions and potentially definitive growth cartilage damage can occur.

  7. Isolation and characterization of polyvalent bacteriophages infecting multi drug resistant Salmonella serovars isolated from broilers in Egypt.

    Science.gov (United States)

    Mahmoud, Mayada; Askora, Ahmed; Barakat, Ahmed Barakat; Rabie, Omar El-Farouk; Hassan, Sayed Emam

    2018-02-02

    In this study, we isolated and characterized three phages named as Salmacey1, Salmacey2 and Salmacey3, infecting multi drug resistant Salmonella serovars isolated from broilers in Egypt. The most prevalent Salmonella serovars were S. typhimurium, S. enteritidis, and S. kentucky. All these Salmonella serovars were found to be resistant to more than two of the ten antimicrobial agents tested. Only S. kentucky was found to be resistant to seven antimicrobial agents. Examination of these phage particles by transmission electron microscopy (TEM), demonstrated that two phages (Salmacey1, Salmacey2) were found to belong to family Siphoviridae, and Salmacey3 was assigned to the family Myoviridae. The results of host range assay revealed that these bacteriophages were polyvalent and thus capable of infecting four strains of Salmonella serovars and Citrobacter freundii. Moreover, the two phages (Salmacey1, Salmacey2) had a lytic effect on Enterobacter cloacae and Salmacey3 was able to infect E. coli. All phages could not infect S. para Typhi, Staphylococus aureus and Bacillus cereus. One-step growth curves of bacteriophages revealed that siphovirus phages (Salmacey1, Salmacey2) have burst size (80 and 90pfu per infected cell with latent period 35min and 40min respectively), and for the myovirus Salmacey3 had a burst size 110pfu per infected cell with latent period 60min. Molecular analyses indicated that these phages contained double-stranded DNA genomes. The lytic activity of the phages against the most multidrug resistant serovars S. kentucky as host strain was evaluated. The result showed that these bacteriophages were able to completely stop the growth of S. kentucky in vitro. These results suggest that phages have a high potential for phage application to control Salmonella serovars isolated from broilers in Egypt. Copyright © 2017. Published by Elsevier B.V.

  8. RNA Sequencing Reveals that Kaposi Sarcoma-Associated Herpesvirus Infection Mimics Hypoxia Gene Expression Signature

    Science.gov (United States)

    Viollet, Coralie; Davis, David A.; Tekeste, Shewit S.; Reczko, Martin; Pezzella, Francesco; Ragoussis, Jiannis

    2017-01-01

    Kaposi sarcoma-associated herpesvirus (KSHV) causes several tumors and hyperproliferative disorders. Hypoxia and hypoxia-inducible factors (HIFs) activate latent and lytic KSHV genes, and several KSHV proteins increase the cellular levels of HIF. Here, we used RNA sequencing, qRT-PCR, Taqman assays, and pathway analysis to explore the miRNA and mRNA response of uninfected and KSHV-infected cells to hypoxia, to compare this with the genetic changes seen in chronic latent KSHV infection, and to explore the degree to which hypoxia and KSHV infection interact in modulating mRNA and miRNA expression. We found that the gene expression signatures for KSHV infection and hypoxia have a 34% overlap. Moreover, there were considerable similarities between the genes up-regulated by hypoxia in uninfected (SLK) and in KSHV-infected (SLKK) cells. hsa-miR-210, a HIF-target known to have pro-angiogenic and anti-apoptotic properties, was significantly up-regulated by both KSHV infection and hypoxia using Taqman assays. Interestingly, expression of KSHV-encoded miRNAs was not affected by hypoxia. These results demonstrate that KSHV harnesses a part of the hypoxic cellular response and that a substantial portion of hypoxia-induced changes in cellular gene expression are induced by KSHV infection. Therefore, targeting hypoxic pathways may be a useful way to develop therapeutic strategies for KSHV-related diseases. PMID:28046107

  9. Isolation and characterization of a virus infecting the freshwater algae Chrysochromulina parva

    International Nuclear Information System (INIS)

    Mirza, S.F.; Staniewski, M.A.; Short, C.M.; Long, A.M.; Chaban, Y.V.; Short, S.M.

    2015-01-01

    Water samples from Lake Ontario, Canada were tested for lytic activity against the freshwater haptophyte algae Chrysochromulina parva. A filterable lytic agent was isolated and identified as a virus via transmission electron microscopy and molecular methods. The virus, CpV-BQ1, is icosahedral, ca. 145 nm in diameter, assembled within the cytoplasm, and has a genome size of ca. 485 kb. Sequences obtained through PCR-amplification of DNA polymerase (polB) genes clustered among sequences from the family Phycodnaviridae, whereas major capsid protein (MCP) sequences clustered among sequences from either the Phycodnaviridae or Mimiviridae. Based on quantitative molecular assays, C. parva's abundance in Lake Ontario was relatively stable, yet CpV-BQ1's abundance was variable suggesting complex virus-host dynamics. This study demonstrates that CpV-BQ1 is a member of the proposed order Megavirales with characteristics of both phycodnaviruses and mimiviruses indicating that, in addition to its complex ecological dynamics, it also has a complex evolutionary history. - Highlights: • A virus infecting the algae C. parva was isolated from Lake Ontario. • Virus characteristics demonstrated that this novel virus is an NCLDV. • The virus's polB sequence suggests taxonomic affiliation with the Phycodnaviridae. • The virus's capsid protein sequences also suggest Mimiviridae ancestry. • Surveys of host and virus natural abundances revealed complex host–virus dynamics.

  10. Isolation and characterization of a virus infecting the freshwater algae Chrysochromulina parva

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, S.F. [Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, Canada L5L 1C6 (Canada); Staniewski, M.A. [Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2 (Canada); Short, C.M. [Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, Canada L5L 1C6 (Canada); Long, A.M. [Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2 (Canada); Chaban, Y.V. [Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, Canada L5L 1C6 (Canada); Short, S.M., E-mail: steven.short@utoronto.ca [Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, Canada L5L 1C6 (Canada); Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2 (Canada)

    2015-12-15

    Water samples from Lake Ontario, Canada were tested for lytic activity against the freshwater haptophyte algae Chrysochromulina parva. A filterable lytic agent was isolated and identified as a virus via transmission electron microscopy and molecular methods. The virus, CpV-BQ1, is icosahedral, ca. 145 nm in diameter, assembled within the cytoplasm, and has a genome size of ca. 485 kb. Sequences obtained through PCR-amplification of DNA polymerase (polB) genes clustered among sequences from the family Phycodnaviridae, whereas major capsid protein (MCP) sequences clustered among sequences from either the Phycodnaviridae or Mimiviridae. Based on quantitative molecular assays, C. parva's abundance in Lake Ontario was relatively stable, yet CpV-BQ1's abundance was variable suggesting complex virus-host dynamics. This study demonstrates that CpV-BQ1 is a member of the proposed order Megavirales with characteristics of both phycodnaviruses and mimiviruses indicating that, in addition to its complex ecological dynamics, it also has a complex evolutionary history. - Highlights: • A virus infecting the algae C. parva was isolated from Lake Ontario. • Virus characteristics demonstrated that this novel virus is an NCLDV. • The virus's polB sequence suggests taxonomic affiliation with the Phycodnaviridae. • The virus's capsid protein sequences also suggest Mimiviridae ancestry. • Surveys of host and virus natural abundances revealed complex host–virus dynamics.

  11. CUX1/Wnt signaling regulates Epithelial Mesenchymal Transition in EBV infected epithelial cells

    International Nuclear Information System (INIS)

    Malizia, Andrea P.; Lacey, Noreen; Walls, Dermot; Egan, Jim J.; Doran, Peter P.

    2009-01-01

    Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGFβ1-mediated lytic phase. EBV lytic reactivation by TGFβ1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM 1 81552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.

  12. CUX1/Wnt signaling regulates Epithelial Mesenchymal Transition in EBV infected epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Malizia, Andrea P.; Lacey, Noreen [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland); Walls, Dermot [School of Biotechnology, Dublin City University. Dublin, 9. Ireland (Ireland); Egan, Jim J. [Advanced Lung Disease and Lung Transplant Program, Mater Misericordiae University Hospital. 44, Eccles Street. Dublin, 7. Ireland (Ireland); Doran, Peter P., E-mail: peter.doran@ucd.ie [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland)

    2009-07-01

    Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGF{beta}1-mediated lytic phase. EBV lytic reactivation by TGF{beta}1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM{sub 1}81552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.

  13. The lytic origin of herpesvirus papio is highly homologous to Epstein-Barr virus ori-Lyt: evolutionary conservation of transcriptional activation and replication signals.

    Science.gov (United States)

    Ryon, J J; Fixman, E D; Houchens, C; Zong, J; Lieberman, P M; Chang, Y N; Hayward, G S; Hayward, S D

    1993-01-01

    Herpesvirus papio (HVP) is a B-lymphotropic baboon virus with an estimated 40% homology to Epstein-Barr virus (EBV). We have cloned and sequenced ori-Lyt of herpesvirus papio and found a striking degree of nucleotide homology (89%) with ori-Lyt of EBV. Transcriptional elements form an integral part of EBV ori-Lyt. The promoter and enhancer domains of EBV ori-Lyt are conserved in herpesvirus papio. The EBV ori-Lyt promoter contains four binding sites for the EBV lytic cycle transactivator Zta, and the enhancer includes one Zta and two Rta response elements. All five of the Zta response elements and one of the Rta motifs are conserved in HVP ori-Lyt, and the HVP DS-L leftward promoter and the enhancer were activated in transient transfection assays by the EBV Zta and Rta transactivators. The EBV ori-Lyt enhancer contains a palindromic sequence, GGTCAGCTGACC, centered on a PvuII restriction site. This sequence, with a single base change, is also present in the HVP ori-Lyt enhancer. DNase I footprinting demonstrated that the PvuII sequence was bound by a protein present in a Raji nuclear extract. Mobility shift and competition assays using oligonucleotide probes identified this sequence as a binding site for the cellular transcription factor MLTF. Mutagenesis of the binding site indicated that MLTF contributes significantly to the constitutive activity of the ori-Lyt enhancer. The high degree of conservation of cis-acting signal sequences in HVP ori-Lyt was further emphasized by the finding that an HVP ori-Lyt-containing plasmid was replicated in Vero cells by a set of cotransfected EBV replication genes. The central domain of EBV ori-Lyt contains two related AT-rich palindromes, one of which is partially duplicated in the HVP sequence. The AT-rich palindromes are functionally important cis-acting motifs. Deletion of these palindromes severely diminished replication of an ori-Lyt target plasmid. Images PMID:8389916

  14. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Arcangeletti, Maria-Cristina, E-mail: mariacristina.arcangeletti@unipr.it [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Germini, Diego; Rodighiero, Isabella [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Mirandola, Prisco [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); De Conto, Flora; Medici, Maria-Cristina [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Gatti, Rita [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); Chezzi, Carlo; Calderaro, Adriana [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy)

    2013-05-25

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

  15. Phage therapy is effective against infection by Mycobacterium ulcerans in a murine footpad model.

    Directory of Open Access Journals (Sweden)

    Gabriela Trigo

    Full Text Available BACKGROUND: Buruli Ulcer (BU is a neglected, necrotizing skin disease caused by Mycobacterium ulcerans. Currently, there is no vaccine against M. ulcerans infection. Although the World Health Organization recommends a combination of rifampicin and streptomycin for the treatment of BU, clinical management of advanced stages is still based on the surgical resection of infected skin. The use of bacteriophages for the control of bacterial infections has been considered as an alternative or to be used in association with antibiotherapy. Additionally, the mycobacteriophage D29 has previously been shown to display lytic activity against M. ulcerans isolates. METHODOLOGY/PRINCIPAL FINDINGS: We used the mouse footpad model of M. ulcerans infection to evaluate the therapeutic efficacy of treatment with mycobacteriophage D29. Analyses of macroscopic lesions, bacterial burdens, histology and cytokine production were performed in both M. ulcerans-infected footpads and draining lymph nodes (DLN. We have demonstrated that a single subcutaneous injection of the mycobacteriophage D29, administered 33 days after bacterial challenge, was sufficient to decrease pathology and to prevent ulceration. This protection resulted in a significant reduction of M. ulcerans numbers accompanied by an increase of cytokine levels (including IFN-γ, both in footpads and DLN. Additionally, mycobacteriophage D29 treatment induced a cellular infiltrate of a lymphocytic/macrophagic profile. CONCLUSIONS/SIGNIFICANCE: Our observations demonstrate the potential of phage therapy against M. ulcerans infection, paving the way for future studies aiming at the development of novel phage-related therapeutic approaches against BU.

  16. Rotavirus infection

    Science.gov (United States)

    Crawford, Sue E.; Ramani, Sasirekha; Tate, Jacqueline E.; Parashar, Umesh D.; Svensson, Lennart; Hagbom, Marie; Franco, Manuel A.; Greenberg, Harry B.; O’Ryan, Miguel; Kang, Gagandeep; Desselberger, Ulrich; Estes, Mary K.

    2017-01-01

    Rotavirus infections are a leading cause of severe, dehydrating gastroenteritis in children rotavirus over a decade ago, rotavirus infections still result in >200,000 deaths annually, mostly in low-income countries. Rotavirus primarily infects enterocytes and induces diarrhoea through the destruction of absorptive enterocytes (leading to malabsorption), intestinal secretion stimulated by rotavirus non-structural protein 4 and activation of the enteric nervous system. In addition, rotavirus infections can lead to antigenaemia (which is associated with more severe manifestations of acute gastroenteritis) and viraemia, and rotavirus can replicate in systemic sites, although this is limited. Reinfections with rotavirus are common throughout life, although the disease severity is reduced with repeat infections. The immune correlates of protection against rotavirus reinfection and recovery from infection are poorly understood, although rotavirus-specific immunoglobulin A has a role in both aspects. The management of rotavirus infection focuses on the prevention and treatment of dehydration, although the use of antiviral and anti-emetic drugs can be indicated in some cases. PMID:29119972

  17. The Performance of the Four Anaerobic Blood Culture Bottles BacT/ALERT-FN, -FN Plus, BACTEC-Plus and -Lytic in Detection of Anaerobic Bacteria and Identification by Direct MALDI-TOF MS.

    Science.gov (United States)

    Almuhayawi, Mohammed; Altun, Osman; Abdulmajeed, Adam Dilshad; Ullberg, Måns; Özenci, Volkan

    2015-01-01

    Detection and identification of anaerobic bacteria in blood cultures (BC) is a well-recognized challenge in clinical microbiology. We studied 100 clinical anaerobic BC isolates to evaluate the performance of BacT/ALERT-FN, -FN Plus (BioMérieux), BACTEC-Plus and -Lytic (Becton Dickinson BioSciences) BC bottles in detection and time to detection (TTD) of anaerobic bacteria. BACTEC Lytic had higher detection rate (94/100, 94%) than BacT/ALERT FN Plus (80/100, 80%) (panaerobic bacteria among the remaining bottle types. The 67 anaerobic bacteria that signalled positive in all four bottle types were analyzed to compare the time to detection (TTD) and isolates were directly identified by MALDI-TOF MS. There was a significant difference in TTD among the four bottle types (panaerobic BC bottles are equally suitable for direct MALDI-TOF MS for rapid and reliable identification of common anaerobic bacteria. Further clinical studies are warranted to investigate the performance of anaerobic BC bottles in detection of anaerobic bacteria and identification by direct MALDI-TOF MS.

  18. Initial stage of transformation of permissive cells by simian virus 40: development of resistance to productive infection.

    Science.gov (United States)

    Hahn, E C; Sauer, G

    1971-07-01

    A quantitative assay has been used to determine the conditions leading to acquisition of resistance of permissive cells to lytic infection. The number of cell colonies surviving infection depends on the occurrence of several cell divisions after infection. High yields of resistant colonies were obtained when infected, confluent cultures were released from contact inhibition 10 to 14 hr after infection. Infection of actively growing cells produced similar results, but halting further division by seeding these growing cells on confluent monolayers prevented the development of colonies. Colony formation was a direct function of multiplicities lower than 5. An inverse killing response was observed with higher multiplicities, yet colonies were produced at a multiplicity of infection as high as 50. Brief exposure of input simian virus 40 to ultraviolet light stimulated colony formation. Irradiation of the virus for longer periods of time led to reduction of colony formation at a rate slower than the rate of inactivation of viral infectivity. It was concluded that resistance is induced by simian virus 40 and that this alteration represents one of the earliest detectable characteristics of the transformation of permissive cells.

  19. Hookworm infection

    Science.gov (United States)

    ... intestinal wall and suck blood, which results in iron deficiency anemia and protein loss. Adult worms and larvae are ... problems that may result from hookworm infection include: Iron deficiency anemia , caused by loss of blood Nutritional deficiencies Severe ...

  20. Breast infection

    Science.gov (United States)

    Mastitis; Infection - breast tissue; Breast abscess ... must continue to breastfeed or pump to relieve breast swelling from milk production. In case if the abscess does not go away, needle aspiration under ultrasound ...

  1. Biofilm Infections

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Jensen, Peter Østrup; Moser, Claus Ernst

    A still increasing interest and emphasis on the sessile bacterial lifestyle biofilms has been seen since it was realized that the vast majority of the total microbial biomass exists as biofilms. Aggregation of bacteria was first described by Leeuwenhoek in 1677, but only recently recognized...... as being important in chronic infection. In 1993 the American Society for Microbiology (ASM) recognized that the biofilm mode of growth was relevant to microbiology. This book covers both the evidence for biofilms in many chronic bacterial infections as well as the problems facing these infections...... such as diagnostics, pathogenesis, treatment regimes and in vitro and in vivo models for studying biofilms. This is the first scientific book on biofilm infections, chapters written by the world leading scientist and clinicians. The intended audience of this book is scientists, teachers at university level as well...

  2. Spinal Infections

    Science.gov (United States)

    ... the wound and re-closing to more extensive debridements and removal of infected tissues. In some cases ... will want to obtain cultures to determine the type of bacteria or fungus that is causing the ...

  3. Neonatal Infections

    Science.gov (United States)

    ... can cause serious problems such as heart disease, brain damage, deafness, visual impairment, or even miscarriage. Infection later in the pregnancy may lead to less severe effects on the fetus but can still cause problems ...

  4. Anaerobic Infections

    Science.gov (United States)

    ... a dental infection or procedure such as a tooth extraction or oral surgery or after trauma to the ... diagnosed, your doctor may treat it with intravenous antibiotics (eg, penicillin, ampicillin) for 4 to 6 weeks, ...

  5. Staph Infections

    Science.gov (United States)

    ... within your body, to produce infections affecting: Internal organs, such as your brain, heart or lungs Bones and muscles Surgically implanted devices, such as artificial joints or cardiac pacemakers Toxic shock syndrome This ...

  6. Campylobacter infection

    Science.gov (United States)

    ... Stool sample testing for white blood cells Stool culture for Campylobacter jejuni Treatment The infection almost always ... some salty foods, such as pretzels, soup, and sports drinks. Eat some high-potassium foods, such as ...

  7. Puerperal infections.

    Science.gov (United States)

    Eschenbach, D A; Wager, G P

    1980-12-01

    This comprehensive review on puerperal infections covers risk factors, causative bacteria, pathophysiology, diagnosis, therapy of specific entities, and prevention. Puerperal infection is problematic to define especially with antibiotics that change the course of fever. I may present as endometritis (most common), myometritis, parametritis, pelvic abscess, salpingitis, septic pelvic thrombophlebitis or septicemia, and also includes infections of the urinary tract, episiotomy, surgical wounds, lacerations or breast. Each of these is discussed in terms of contributing factors, microbiology, clinical findings, diagnosis, treatment, prevention and complications. Risk factors in general are cesarean section, premature rupture of the membranes, internal fetal monitoring, general anesthesia, pelvic examinations. The most common bacterial involved are group B and other streptococci, E. coli, Gardnerella vaginalis, Gram positive anaerobic cocci, Mycoplasma and pre-existing Chlamydial infections. Diagnosis of the causative organism is difficult because of polyinfection and difficulty of getting a sterile endometrial swab. Diagnosis of the infection is equally difficult because of the wide variety of symptoms: fever, abnormal lochia, tachycardia, tenderness, mass and abnormal bowel sounds are common. Therapy depends of the responsible microorganism, although 3 empirical tactics are suggested while awaiting results of culture: 1) choose an antibiotic for the most common aerobic bacteria; 2) an antibiotic effective against B. fragilis and one for aerobic bacteria, e.g. clindamycin and an aminoglycoside; 3) a nontoxic antibiotic active against most aerobic and anaerobic organisms, e.g. doxycycline or cefoxitin. An example of an infection recently described is pudendal-paracervical block infection, often signaled by severe hip pain. It is associated with vaginal bacteria, is usually complicated by abscess even with antibiotic coverage, and may end in paraplegia or fatal sepsis

  8. Spinal infections

    International Nuclear Information System (INIS)

    Tali, E. Turgut; Gueltekin, Serap

    2005-01-01

    Spinal infections have an increasing prevalence among the general population. Definitive diagnosis based solely on clinical grounds is usually not possible and radiological imaging is used in almost all patients. The primary aim of the authors is to present an overview of spinal infections located in epidural, intradural and intramedullary compartments and to provide diagnostic clues regarding different imaging modalities, particularly MRI, to the practicing physicians and radiologists. (orig.)

  9. Isolation and Characterization of a Double Stranded DNA Megavirus Infecting the Toxin-Producing Haptophyte Prymnesium parvum

    Directory of Open Access Journals (Sweden)

    Ben A. Wagstaff

    2017-03-01

    Full Text Available Prymnesium parvum is a toxin-producing haptophyte that causes harmful algal blooms globally, leading to large-scale fish kills that have severe ecological and economic implications. For the model haptophyte, Emiliania huxleyi, it has been shown that large dsDNA viruses play an important role in regulating blooms and therefore biogeochemical cycling, but much less work has been done looking at viruses that infect P. parvum, or the role that these viruses may play in regulating harmful algal blooms. In this study, we report the isolation and characterization of a lytic nucleo-cytoplasmic large DNA virus (NCLDV collected from the site of a harmful P. parvum bloom. In subsequent experiments, this virus was shown to infect cultures of Prymnesium sp. and showed phylogenetic similarity to the extended Megaviridae family of algal viruses.

  10. Infection-Induced Retrotransposon-Derived Noncoding RNAs Enhance Herpesviral Gene Expression via the NF-κB Pathway.

    Directory of Open Access Journals (Sweden)

    John Karijolich

    Full Text Available Short interspersed nuclear elements (SINEs are highly abundant, RNA polymerase III-transcribed noncoding retrotransposons that are silenced in somatic cells but activated during certain stresses including viral infection. How these induced SINE RNAs impact the host-pathogen interaction is unknown. Here we reveal that during murine gammaherpesvirus 68 (MHV68 infection, rapidly induced SINE RNAs activate the antiviral NF-κB signaling pathway through both mitochondrial antiviral-signaling protein (MAVS-dependent and independent mechanisms. However, SINE RNA-based signaling is hijacked by the virus to enhance viral gene expression and replication. B2 RNA expression stimulates IKKβ-dependent phosphorylation of the major viral lytic cycle transactivator protein RTA, thereby enhancing its activity and increasing progeny virion production. Collectively, these findings suggest that SINE RNAs participate in the innate pathogen response mechanism, but that herpesviruses have evolved to co-opt retrotransposon activation for viral benefit.

  11. The Differentiation and Protective Function of Cytolytic CD4 T Cells in Influenza Infection

    Directory of Open Access Journals (Sweden)

    Deborah M. Brown

    2016-03-01

    Full Text Available CD4 T cells that recognize peptide antigen in the context of Class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity (CD4 CTL play a role in chronic, as well as, acute infections such as influenza A virus (IAV infection. In the last couple of decades, techniques to measure the frequency and activity of these cytolytic cells has demonstrated their abundance in infections such as HIV, mouse pox, murine gamma herpes virus, CMV, EBV and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and anti-tumor immunity through their ability to acquire perforin mediated cytolytic activity and contribution to lysis of virally infected targets or tumors. As early as the 1980s, CD4 T cell clones with cytolytic potential were identified after influenza virus infection, yet much of this early work was dependent on in vitro culture and little was known about the physiological relevance of CD4 CTL. Here, we discuss the direct role CD4 CTL play in protection against lethal IAV infection and the factors that drive the generation of perforin mediated lytic activity in CD4 cells in vivo during IAV infection. While focusing on CD4 CTL generated during IAV infection, we pull comparisons from the literature in other anti-viral and anti-tumor systems. Further, we highlight what is currently known about CD4 CTL secondary and memory responses, as well as vaccination strategies to induce these potent killer cells that provide an extra layer of cell mediated immune protection against heterosubtypic IAV infection.

  12. Massive activation of archaeal defense genes during viral infection.

    Science.gov (United States)

    Quax, Tessa E F; Voet, Marleen; Sismeiro, Odile; Dillies, Marie-Agnes; Jagla, Bernd; Coppée, Jean-Yves; Sezonov, Guennadi; Forterre, Patrick; van der Oost, John; Lavigne, Rob; Prangishvili, David

    2013-08-01

    Archaeal viruses display unusually high genetic and morphological diversity. Studies of these viruses proved to be instrumental for the expansion of knowledge on viral diversity and evolution. The Sulfolobus islandicus rod-shaped virus 2 (SIRV2) is a model to study virus-host interactions in Archaea. It is a lytic virus that exploits a unique egress mechanism based on the formation of remarkable pyramidal structures on the host cell envelope. Using whole-transcriptome sequencing, we present here a global map defining host and viral gene expression during the infection cycle of SIRV2 in its hyperthermophilic host S. islandicus LAL14/1. This information was used, in combination with a yeast two-hybrid analysis of SIRV2 protein interactions, to advance current understanding of viral gene functions. As a consequence of SIRV2 infection, transcription of more than one-third of S. islandicus genes was differentially regulated. While expression of genes involved in cell division decreased, those genes playing a role in antiviral defense were activated on a large scale. Expression of genes belonging to toxin-antitoxin and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems was specifically pronounced. The observed different degree of activation of various CRISPR-Cas systems highlights the specialized functions they perform. The information on individual gene expression and activation of antiviral defense systems is expected to aid future studies aimed at detailed understanding of the functions and interplay of these systems in vivo.

  13. Urinary Tract Infection (UTI)

    Science.gov (United States)

    ... Home A-Z Health Topics Urinary tract infections Urinary tract infections > A-Z Health Topics Urinary tract infections (PDF, ... Embed Subscribe To receive Publications email updates Submit Urinary tract infections Urinary tract infections (UTIs) are most often caused ...

  14. Cytoarchitecture of Zika virus infection in human neuroblastoma and Aedes albopictus cell lines

    International Nuclear Information System (INIS)

    Offerdahl, Danielle K.; Dorward, David W.; Hansen, Bryan T.; Bloom, Marshall E.

    2017-01-01

    The Zika virus (ZIKV) pandemic is a global concern due to its role in the development of congenital anomalies of the central nervous system. This mosquito-borne flavivirus alternates between mammalian and mosquito hosts, but information about the biogenesis of ZIKV is limited. Using a human neuroblastoma cell line (SK-N-SH) and an Aedes albopictus mosquito cell line (C6/36), we characterized ZIKV infection by immunofluorescence, transmission electron microscopy (TEM), and electron tomography (ET) to better understand infection in these disparate host cells. ZIKV replicated well in both cell lines, but infected SK-N-SH cells suffered a lytic crisis. Flaviviruses scavenge host cell membranes to serve as replication platforms and ZIKV showed the hallmarks of this process. Via TEM, we identified virus particles and 60–100 nm spherular vesicles. ET revealed these vesicular replication compartments contain smaller 20–30 nm spherular structures. Our studies indicate that SK-N-SH and C6/36 cells are relevant models for viral cytoarchitecture study. - Highlights: •First electron tomography of Zika virus cytoarchitecture. •Comparison of Zika virus infection in human neuroblastoma and mosquito cells. •Ultrastructure of Zika virus infection in human neuroblastoma and mosquito cells.

  15. Cytoarchitecture of Zika virus infection in human neuroblastoma and Aedes albopictus cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Offerdahl, Danielle K. [Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT (United States); Dorward, David W.; Hansen, Bryan T. [Microscopy Unit, Research Technology Branch, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT (United States); Bloom, Marshall E., E-mail: mbloom@nih.gov [Laboratory of Virology, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT (United States)

    2017-01-15

    The Zika virus (ZIKV) pandemic is a global concern due to its role in the development of congenital anomalies of the central nervous system. This mosquito-borne flavivirus alternates between mammalian and mosquito hosts, but information about the biogenesis of ZIKV is limited. Using a human neuroblastoma cell line (SK-N-SH) and an Aedes albopictus mosquito cell line (C6/36), we characterized ZIKV infection by immunofluorescence, transmission electron microscopy (TEM), and electron tomography (ET) to better understand infection in these disparate host cells. ZIKV replicated well in both cell lines, but infected SK-N-SH cells suffered a lytic crisis. Flaviviruses scavenge host cell membranes to serve as replication platforms and ZIKV showed the hallmarks of this process. Via TEM, we identified virus particles and 60–100 nm spherular vesicles. ET revealed these vesicular replication compartments contain smaller 20–30 nm spherular structures. Our studies indicate that SK-N-SH and C6/36 cells are relevant models for viral cytoarchitecture study. - Highlights: •First electron tomography of Zika virus cytoarchitecture. •Comparison of Zika virus infection in human neuroblastoma and mosquito cells. •Ultrastructure of Zika virus infection in human neuroblastoma and mosquito cells.

  16. Cerebral infections

    Energy Technology Data Exchange (ETDEWEB)

    Karampekios, Spyros [University of Crete, Department of Radiology, Heraklion, Crete (Greece); Hesselink, John [UCSD, Department of Radiology, San Diego, CA (United States)

    2005-03-01

    Despite the development of many effective antibiotic therapies and the general improvement in hygiene and health care systems all over the world, the incidence of central nervous system (CNS) infection has increased significantly in the past 15 years. This can be attributed primarily to the acquired immunodeficiency syndrome (AIDS) epidemic and its devastating effect on the immune system and secondarily to various immunosuppressive agents that are being used in aggressive cancer treatment and in organ transplantations. The brain particularly is protected from infection by the calvarium, meninges and blood brain barrier. However, different types of pathogens, including bacteria, viruses, fungi and parasites, can reach the brain hematogenously or, less likely, by direct extension from an adjacent infected focus. The early detection and specific diagnosis of infection are of great importance, since brain infections are potentially treatable diseases. Imaging studies play a crucial role in the diagnostic process, along with the history (exposure to infectious agents), host factors (open head trauma, CSF leak, sinusitis, otitis, immune status), physical examination and laboratory analysis of CSF. (orig.)

  17. Cerebral infections

    International Nuclear Information System (INIS)

    Karampekios, Spyros; Hesselink, John

    2005-01-01

    Despite the development of many effective antibiotic therapies and the general improvement in hygiene and health care systems all over the world, the incidence of central nervous system (CNS) infection has increased significantly in the past 15 years. This can be attributed primarily to the acquired immunodeficiency syndrome (AIDS) epidemic and its devastating effect on the immune system and secondarily to various immunosuppressive agents that are being used in aggressive cancer treatment and in organ transplantations. The brain particularly is protected from infection by the calvarium, meninges and blood brain barrier. However, different types of pathogens, including bacteria, viruses, fungi and parasites, can reach the brain hematogenously or, less likely, by direct extension from an adjacent infected focus. The early detection and specific diagnosis of infection are of great importance, since brain infections are potentially treatable diseases. Imaging studies play a crucial role in the diagnostic process, along with the history (exposure to infectious agents), host factors (open head trauma, CSF leak, sinusitis, otitis, immune status), physical examination and laboratory analysis of CSF. (orig.)

  18. Epidemiological markers of Serratia marcescens isolates causing nosocomial infections in Spain (1981-1991).

    Science.gov (United States)

    Boquete, T; Vindel, A; Martin-Bourgon, C; Azañedo, L; Sáez-Nieto, J A

    1996-12-01

    The distribution of epidemiological markers (serotyping and phage-typing) of Serratia marcescens isolates from nosocomial episodes (63 nosocomial cutbreaks with 475 isolates, and 1208 sporadic cases) received in our laboratory during the period 1981-1991 was studied. The records for 1683 isolates from Spanish hospitals have been analyzed. In relation with the sporadic cases, the predominant types were serotype O6 (13.4%) and serotype O14 (11.4%); polyagglutinable strains accounted for 15.6%; in outbreaks, type O14 is clearly predominant (27.4%). Phage-typing was a good secondary marker, with a 87.9% of typability; the number of lytic patterns was very high, extended patterns (six or more phages) being the most frequent. We have studied the characteristics of S. marcescens isolates causing infections in the nosocomial environment in Spain.

  19. Translational profiling of B cells infected with the Epstein-Barr virus reveals 5' leader ribosome recruitment through upstream open reading frames.

    Science.gov (United States)

    Bencun, Maja; Klinke, Olaf; Hotz-Wagenblatt, Agnes; Klaus, Severina; Tsai, Ming-Han; Poirey, Remy; Delecluse, Henri-Jacques

    2018-04-06

    The Epstein-Barr virus (EBV) genome encodes several hundred transcripts. We have used ribosome profiling to characterize viral translation in infected cells and map new translation initiation sites. We show here that EBV transcripts are translated with highly variable efficiency, owing to variable transcription and translation rates, variable ribosome recruitment to the leader region and coverage by monosomes versus polysomes. Some transcripts were hardly translated, others mainly carried monosomes, showed ribosome accumulation in leader regions and most likely represent non-coding RNAs. A similar process was visible for a subset of lytic genes including the key transactivators BZLF1 and BRLF1 in cells infected with weakly replicating EBV strains. This suggests that ribosome trapping, particularly in the leader region, represents a new checkpoint for the repression of lytic replication. We could identify 25 upstream open reading frames (uORFs) located upstream of coding transcripts that displayed 5' leader ribosome trapping, six of which were located in the leader region shared by many latent transcripts. These uORFs repressed viral translation and are likely to play an important role in the regulation of EBV translation.

  20. The Translesion Polymerase Pol η Is Required for Efficient Epstein-Barr Virus Infectivity and Is Regulated by the Viral Deubiquitinating Enzyme BPLF1.

    Science.gov (United States)

    Dyson, Ossie F; Pagano, Joseph S; Whitehurst, Christopher B

    2017-10-01

    Epstein-Barr virus (EBV) infection and lytic replication are known to induce a cellular DNA damage response. We previously showed that the virally encoded BPLF1 protein interacts with and regulates several members of the translesion synthesis (TLS) pathway, a DNA damage tolerance pathway, and that these cellular factors enhance viral infectivity. BPLF1 is a late lytic cycle gene, but the protein is also packaged in the viral tegument, indicating that BPLF1 may function both early and late during infection. The BPLF1 protein expresses deubiquitinating activity that is strictly conserved across the Herpesviridae ; mutation of the active site cysteine results in a loss of enzymatic activity. Infection with an EBV BPLF1 knockout virus results in decreased EBV infectivity. Polymerase eta (Pol η), a specialized DNA repair polymerase, functions in TLS and allows for DNA replication complexes to bypass lesions in DNA. Here we report that BPLF1 interacts with Pol η and that Pol η protein levels are increased in the presence of functional BPLF1. BPLF1 promotes a nuclear relocalization of Pol η molecules which are focus-like in appearance, consistent with the localization observed when Pol η is recruited to sites of DNA damage. Knockdown of Pol η resulted in decreased production of infectious virus, and further, Pol η was found to bind to EBV DNA, suggesting that it may allow for bypass of damaged viral DNA during its replication. The results suggest a mechanism by which EBV recruits cellular repair factors, such as Pol η, to sites of viral DNA damage via BPLF1, thereby allowing for efficient viral DNA replication. IMPORTANCE Epstein-Barr virus is the causative agent of infectious mononucleosis and infects approximately 90% of the world's population. It causes lymphomas in individuals with acquired and innate immune disorders and is strongly associated with Hodgkin's lymphoma, Burkitt's lymphoma, diffuse large B-cell lymphomas, nasopharyngeal carcinoma (NPC), and

  1. Lysis-deficient phages as novel therapeutic agents for controlling bacterial infection

    Directory of Open Access Journals (Sweden)

    Kempashanaiah Nanjundappa

    2011-08-01

    Full Text Available Abstract Background Interest in phage therapy has grown over the past decade due to the rapid emergence of antibiotic resistance in bacterial pathogens. However, the use of bacteriophages for therapeutic purposes has raised concerns over the potential for immune response, rapid toxin release by the lytic action of phages, and difficulty in dose determination in clinical situations. A phage that kills the target cell but is incapable of host cell lysis would alleviate these concerns without compromising efficacy. Results We developed a recombinant lysis-deficient Staphylococcus aureus phage P954, in which the endolysin gene was rendered nonfunctional by insertional inactivation. P954, a temperate phage, was lysogenized in S. aureus strain RN4220. The native endolysin gene on the prophage was replaced with an endolysin gene disrupted by the chloramphenicol acetyl transferase (cat gene through homologous recombination using a plasmid construct. Lysogens carrying the recombinant phage were detected by growth in presence of chloramphenicol. Induction of the recombinant prophage did not result in host cell lysis, and the phage progeny were released by cell lysis with glass beads. The recombinant phage retained the endolysin-deficient genotype and formed plaques only when endolysin was supplemented. The host range of the recombinant phage was the same as that of the parent phage. To test the in vivo efficacy of the recombinant endolysin-deficient phage, immunocompromised mice were challenged with pathogenic S. aureus at a dose that results in 80% mortality (LD80. Treatment with the endolysin-deficient phage rescued mice from the fatal S. aureus infection. Conclusions A recombinant endolysin-deficient staphylococcal phage has been developed that is lethal to methicillin-resistant S. aureus without causing bacterial cell lysis. The phage was able to multiply in lytic mode utilizing a heterologous endolysin expressed from a plasmid in the propagation host

  2. De novo fatty acid biosynthesis contributes significantly to establishment of a bioenergetically favorable environment for vaccinia virus infection.

    Directory of Open Access Journals (Sweden)

    Matthew D Greseth

    2014-03-01

    Full Text Available The poxvirus life cycle, although physically autonomous from the host nucleus, is nevertheless dependent upon cellular functions. A requirement for de novo fatty acid biosynthesis was implied by our previous demonstration that cerulenin, a fatty acid synthase inhibitor, impaired vaccinia virus production. Here we show that additional inhibitors of this pathway, TOFA and C75, reduce viral yield significantly, with partial rescue provided by exogenous palmitate, the pathway's end-product. Palmitate's major role during infection is not for phospholipid synthesis or protein palmitoylation. Instead, the mitochondrial import and β-oxidation of palmitate are essential, as shown by the impact of etomoxir and trimetazidine, which target these two processes respectively. Moreover, the impact of these inhibitors is exacerbated in the absence of exogenous glucose, which is otherwise dispensable for infection. In contrast to glucose, glutamine is essential for productive viral infection, providing intermediates that sustain the TCA cycle (anaplerosis. Cumulatively, these data suggest that productive infection requires the mitochondrial β-oxidation of palmitate which drives the TCA cycle and energy production. Additionally, infection causes a significant rise in the cellular oxygen consumption rate (ATP synthesis that is ablated by etomoxir. The biochemical progression of the vaccinia life cycle is not impaired in the presence of TOFA, C75, or etomoxir, although the levels of viral DNA and proteins synthesized are somewhat diminished. However, by reversibly arresting infections at the onset of morphogenesis, and then monitoring virus production after release of the block, we determined that virion assembly is highly sensitive to TOFA and C75. Electron microscopic analysis of cells released into C75 revealed fragmented aggregates of viroplasm which failed to be enclosed by developing virion membranes. Taken together, these data indicate that vaccinia

  3. De novo fatty acid biosynthesis contributes significantly to establishment of a bioenergetically favorable environment for vaccinia virus infection.

    Science.gov (United States)

    Greseth, Matthew D; Traktman, Paula

    2014-03-01

    The poxvirus life cycle, although physically autonomous from the host nucleus, is nevertheless dependent upon cellular functions. A requirement for de novo fatty acid biosynthesis was implied by our previous demonstration that cerulenin, a fatty acid synthase inhibitor, impaired vaccinia virus production. Here we show that additional inhibitors of this pathway, TOFA and C75, reduce viral yield significantly, with partial rescue provided by exogenous palmitate, the pathway's end-product. Palmitate's major role during infection is not for phospholipid synthesis or protein palmitoylation. Instead, the mitochondrial import and β-oxidation of palmitate are essential, as shown by the impact of etomoxir and trimetazidine, which target these two processes respectively. Moreover, the impact of these inhibitors is exacerbated in the absence of exogenous glucose, which is otherwise dispensable for infection. In contrast to glucose, glutamine is essential for productive viral infection, providing intermediates that sustain the TCA cycle (anaplerosis). Cumulatively, these data suggest that productive infection requires the mitochondrial β-oxidation of palmitate which drives the TCA cycle and energy production. Additionally, infection causes a significant rise in the cellular oxygen consumption rate (ATP synthesis) that is ablated by etomoxir. The biochemical progression of the vaccinia life cycle is not impaired in the presence of TOFA, C75, or etomoxir, although the levels of viral DNA and proteins synthesized are somewhat diminished. However, by reversibly arresting infections at the onset of morphogenesis, and then monitoring virus production after release of the block, we determined that virion assembly is highly sensitive to TOFA and C75. Electron microscopic analysis of cells released into C75 revealed fragmented aggregates of viroplasm which failed to be enclosed by developing virion membranes. Taken together, these data indicate that vaccinia infection, and in

  4. Campylobacter Infections

    Science.gov (United States)

    ... contact with fecal matter (poop) from an infected person (especially a child in diapers). Household pets can carry and spread the bacteria to people. ... preparing food. Clean and disinfect toilets after the person with diarrhea uses them. Also, if a pet dog or cat has diarrhea, wash your hands ...

  5. Baylisascaris Infection

    Centers for Disease Control (CDC) Podcasts

    2012-08-27

    This podcast will educate health care providers on diagnosing baylisascariasis and on providing patients at risk of Baylisascaris infection with prevention messages.  Created: 8/27/2012 by Center for Global Health, Division of Parasitic Diseases and Malaria.   Date Released: 8/28/2012.

  6. Hand Infections

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Hand Infections Email to a friend * required fields ...

  7. Metapneumovirus infections

    Science.gov (United States)

    Avian metapneumovirus (aMPV) causes turkey rhinotracheitis (TRT), an acute upper respiratory tract infection of turkeys, and is also associated with swollen head syndrome (SHS) in chickens and egg production losses in layers. Since the first TRT reported in the late 1970s in South Africa, the virus...

  8. Characterization of free lytic bacteriophages isolated from compost against O145 Shiga toxin-producing Escherichia coli (STEC) as a potential biocontrol agent

    Science.gov (United States)

    Shiga toxin-producing E. coli (STEC), one of the most prevalent foodborne pathogens, are notorious for hemolytic uremic syndrome (HUS) and causing high mortality among children and the elder population after infection. Besides O157 STEC, non-O157 STEC—particularly serogroup O145—is commonly associat...

  9. Rational site-directed mutations of the LLP-1 and LLP-2 lentivirus lytic peptide domains in the intracytoplasmic tail of human immunodeficiency virus type 1 gp41 indicate common functions in cell-cell fusion but distinct roles in virion envelope incorporation.

    Science.gov (United States)

    Kalia, Vandana; Sarkar, Surojit; Gupta, Phalguni; Montelaro, Ronald C

    2003-03-01

    Two highly conserved cationic amphipathic alpha-helical motifs, designated lentivirus lytic peptides 1 and 2 (LLP-1 and LLP-2), have been characterized in the carboxyl terminus of the transmembrane (TM) envelope glycoprotein (Env) of lentiviruses. Although various properties have been attributed to these domains, their structural and functional significance is not clearly understood. To determine the specific contributions of the Env LLP domains to Env expression, processing, and incorporation and to viral replication and syncytium induction, site-directed LLP mutants of a primary dualtropic infectious human immunodeficiency virus type 1 (HIV-1) isolate (ME46) were examined. Substitutions were made for highly conserved arginine residues in either the LLP-1 or LLP-2 domain (MX1 or MX2, respectively) or in both domains (MX4). The HIV-1 mutants with altered LLP domains demonstrated distinct phenotypes. The LLP-1 mutants (MX1 and MX4) were replication defective and showed an average of 85% decrease in infectivity, which was associated with an evident decrease in gp41 incorporation into virions without a significant decrease in Env expression or processing in transfected 293T cells. In contrast, MX2 virus was replication competent and incorporated a full complement of Env into its virions, indicating a differential role for the LLP-1 domain in Env incorporation. Interestingly, the replication-competent MX2 virus was impaired in its ability to induce syncytia in T-cell lines. This defect in cell-cell fusion did not correlate with apparent defects in the levels of cell surface Env expression, oligomerization, or conformation. The lack of syncytium formation, however, correlated with a decrease of about 90% in MX2 Env fusogenicity compared to that of wild-type Env in quantitative luciferase-based cell-cell fusion assays. The LLP-1 mutant MX1 and MX4 Envs also exhibited an average of 80% decrease in fusogenicity. Altogether, these results demonstrate for the first time that

  10. Fish tapeworm infection

    Science.gov (United States)

    Fish tapeworm infection is an intestinal infection with a parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

  11. Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

    Directory of Open Access Journals (Sweden)

    Kyle C Jensen

    Full Text Available Staphylococcus aureus (SA is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

  12. Telomerase Activity Impacts on Epstein-Barr Virus Infection of AGS Cells

    Science.gov (United States)

    Rac, Jürgen; Haas, Florian; Schumacher, Andrina; Middeldorp, Jaap M.; Delecluse, Henri-Jacques; Speck, Roberto F.

    2015-01-01

    The Epstein-Barr virus (EBV) is transmitted from host-to-host via saliva and is associated with epithelial malignancies including nasopharyngeal carcinoma (NPC) and some forms of gastric carcinoma (GC). Nevertheless, EBV does not transform epithelial cells in vitro where it is rapidly lost from infected primary epithelial cells or epithelial tumor cells. Long-term infection by EBV, however, can be established in hTERT-immortalized nasopharyngeal epithelial cells. Here, we hypothesized that increased telomerase activity in epithelial cells enhances their susceptibility to infection by EBV. Using HONE-1, AGS and HEK293 cells we generated epithelial model cell lines with increased or suppressed telomerase activity by stable ectopic expression of hTERT or of a catalytically inactive, dominant negative hTERT mutant. Infection experiments with recombinant prototypic EBV (rB95.8), recombinant NPC EBV (rM81) with increased epithelial cell tropism compared to B95.8, or recombinant B95.8 EBV with BZLF1-knockout that is not able to undergo lytic replication, revealed that infection frequencies positively correlate with telomerase activity in AGS cells but also partly depend on the cellular background. AGS cells with increased telomerase activity showed increased expression mainly of latent EBV genes, suggesting that increased telomerase activity directly acts on the EBV infection of epithelial cells by facilitating latent EBV gene expression early upon virus inoculation. Thus, our results indicate that infection of epithelial cells by EBV is a very selective process involving, among others, telomerase activity and cellular background to allow for optimized host-to-host transmission via saliva. PMID:25856387

  13. A novel Cre recombinase imaging system for tracking lymphotropic virus infection in vivo.

    Directory of Open Access Journals (Sweden)

    Bernadette M Dutia

    2009-08-01

    Full Text Available Detection, isolation, and identification of individual virus infected cells during long term infection are critical to advance our understanding of mechanisms of pathogenesis for latent/persistent viruses. However, current approaches to study these viruses in vivo have been hampered by low sensitivity and effects of cell-type on expression of viral encoded reporter genes. We have designed a novel Cre recombinase (Cre-based murine system to overcome these problems, and thereby enable tracking and isolation of individual in vivo infected cells.Murine gammaherpesvirus 68 (MHV-68 was used as a prototypic persistent model virus. A Cre expressing recombinant virus was constructed and characterised. The virus is attenuated both in lytic virus replication, producing ten-fold lower lung virus titres than wild type virus, and in the establishment of latency. However, despite this limitation, when the sEGFP7 mouse line containing a Cre-activated enhanced green fluorescent protein (EGFP was infected with the Cre expressing virus, sites of latent and persistent virus infection could be identified within B cells and macrophages of the lymphoid system on the basis of EGFP expression. Importantly, the use of the sEGFP7 mouse line which expresses high levels of EGFP allowed individual virus positive cells to be purified by FACSorting. Virus gene expression could be detected in these cells. Low numbers of EGFP positive cells could also be detected in the bone marrow.The use of this novel Cre-based virus/mouse system allowed identification of individual latently infected cells in vivo and may be useful for the study and long-term monitoring of other latent/persistent virus infections.

  14. Isolation and in vitro evaluation of bacteriophages against MDR-bacterial isolates from septic wound infections.

    Directory of Open Access Journals (Sweden)

    Roja Rani Pallavali

    Full Text Available Multi-drug resistance has become a major problem for the treatment of pathogenic bacterial infections. The use of bacteriophages is an attractive approach to overcome the problem of drug resistance in several pathogens that cause fatal diseases. Our study aimed to isolate multi drug resistant bacteria from patients with septic wounds and then isolate and apply bacteriophages in vitro as alternative therapeutic agents. Pus samples were aseptically collected from Rajiv Gandhi Institute of Medical Science (RIMS, Kadapa, A.P., and samples were analyzed by gram staining, evaluating morphological characteristics, and biochemical methods. MDR-bacterial strains were collected using the Kirby-Bauer disk diffusion method against a variety of antibiotics. Bacteriophages were collected and tested in vitro for lytic activity against MDR-bacterial isolates. Analysis of the pus swab samples revealed that the most of the isolates detected had Pseudomonas aeruginosa as the predominant bacterium, followed by Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Our results suggested that gram-negative bacteria were more predominant than gram-positive bacteria in septic wounds; most of these isolates were resistant to ampicillin, amoxicillin, penicillin, vancomycin and tetracycline. All the gram-positive isolates (100% were multi-drug resistant, whereas 86% of the gram-negative isolates had a drug resistant nature. Further bacteriophages isolated from sewage demonstrated perfect lytic activity against the multi-drug resistant bacteria causing septic wounds. In vitro analysis of the isolated bacteriophages demonstrated perfect lysis against the corresponding MDR-bacteria, and these isolated phages may be promising as a first choice for prophylaxis against wound sepsis, Moreover, phage therapy does not enhance multi-drug resistance in bacteria and could work simultaneously on a wide variety of MDR-bacteria when used in a bacteriophage cocktail. Hence

  15. Bacteriophage ΦSA012 Has a Broad Host Range against Staphylococcus aureus and Effective Lytic Capacity in a Mouse Mastitis Model

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    Hidetomo Iwano

    2018-01-01

    Full Text Available Bovine mastitis is an inflammation of the mammary gland caused by bacterial infection in dairy cattle. It is the most costly disease in the dairy industry because of the high use of antibiotics. Staphylococcus aureus is one of the major causative agents of bovine mastitis and antimicrobial resistance. Therefore, new strategies to control bacterial infection are required in the dairy industry. One potential strategy is bacteriophage (phage therapy. In the present study, we examined the host range of previously isolated S. aureus phages ΦSA012 and ΦSA039 against S. aureus strains isolated from mastitic cows. These phages could kill all S. aureus (93 strains from 40 genotypes and methicillin-resistant S. aureus (six strains from six genotypes strains tested. Using a mouse mastitis model, we demonstrated that ΦSA012 reduced proliferation of S. aureus and inflammation in the mammary gland. Furthermore, intravenous or intraperitoneal phage administration reduced proliferation of S. aureus in the mammary glands. These results suggest that broad host range phages ΦSA012 is potential antibacterial agents for dairy production medicine.

  16. Infective endocarditis

    Directory of Open Access Journals (Sweden)

    Sénior, Juan Manuel

    2015-10-01

    Full Text Available Infective endocarditis is a disease caused by colonization and proliferation of infectious agents on the endothelial surface of the heart. Its clinical presentation is variable, depending upon conditions of the patient, such as immunosuppression, presence of prosthetic material, intravenous drug use, and the etiologic agent. Diagnosis is usually established through the addition of elements such as medical history, physical examination, results of blood cultures, echocardiography and other aids. We present the case of an adult male who came to the hospital with fever and symptoms and signs of acute heart failure. The presence of a systolic murmur was documented in the aortic area, and the echocardiogram revealed severe valve regurgitation and a vegetating lesion on the bicuspid aortic valve. He required valve replacement and completed antibiotic treatment based on the sensitivity of the Streptococcus mitis strain that was demonstrated in the blood cultures.

  17. Combined Effects of Elevated pCO2 and Warming Facilitate Cyanophage Infections

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    Kai Cheng

    2017-06-01

    Full Text Available Elevated pCO2 and warming are generally expected to influence cyanobacterial growth, and may promote the formation of blooms. Yet, both climate change factors may also influence cyanobacterial mortality by favoring pathogens, such as viruses, which will depend on the ability of the host to adapt. To test this hypothesis, we grew Plectonema boryanum IU597 under two temperature (25 and 29°C and two pCO2 (400 and 800 μatm conditions for 1 year, after which all treatments were re-exposed to control conditions for a period of 3 weeks. At several time points during the 1 year period, and upon re-exposure, we measured various infection characteristics of it associated cyanophage PP, including the burst size, latent period, lytic cycle and the efficiency of plaquing (EOP. As expected, elevated pCO2 promoted growth of P. boryanum equally over the 1 year period, but warming did not. Burst size increased in the warm treatment, but decreased in both the elevated pCO2 and combined treatment. The latent period and lytic cycle both became shorter in the elevated pCO2 and higher temperature treatment, and were further reduced by the combined effect of both factors. Efficiency of plaquing (EOP decreased in the elevated pCO2 treatment, increased in the warm treatment, and increased even stronger in the combined treatment. These findings indicate that elevated pCO2 enhanced the effect of warming, thereby further promoting the virus infection rate. The re-exposure experiments demonstrate adaptation of the host leading to higher biomass build-up with elevated pCO2 over the experimental period, and lower performance upon re-exposure to control conditions. Similarly, virus burst size and EOP increased when given warm adapted host, but were lower as compared to the control when the host was re-exposed to control conditions. Our results demonstrate that adaptation but particularly physiological acclimation to climate change conditions favored viral infections, while

  18. Arenavirus Infections

    Directory of Open Access Journals (Sweden)

    Salim Mattar V

    2017-05-01

    Full Text Available The infectious syndromes associated with arenaviruses in South America are four: febrile syndrome of viral origin; Haemorrhagic fevers with or without neurological involvement; Aseptic meningitis and meningo-encephalitis. Among the Arenavirus of the new world is the Tacaribe complex where the viruses are found: Junín (Argentina, Guanarito (Venezuela, Machupo (Bolivia and Sabiá (Brazil, which are characterized by hemorrhagic fevers. In Colombia the arenavirus Pichindé was isolated in 1965, from the rodent Oryzomys albigularis, in the valley of Pichindé (Valle del Cauca. This arenavirus produces a persistent infection in its host and is not pathogenic for the man. There is evidence of the circulation of the Guanarito virus in rodents from Córdoba, but there are no cases diagnosed in humans; In Colombia, the genome of the lymphocytic choriomeningitis virus was detected in the brains of rodents Mus musculus. The diagnosis is based on the knowledge of local epidemiology and the suspicion of a patient with fever in endemic areas, where infections such as malaria, dengue and leptospirosis, sepsis of bacterial origin and rickectomy have been excluded. Virus isolation in the feverish period is the gold standart, but it implies contact with the virus that is highly infectious, which represents a public health problem. Serology has been used for diagnosis, but there is no commercial evidence and only research groups and large public health laboratories have these tests. Most of the patients present a moderate severity, which needs adequate hydration, antipyretics and anti-inflammatories. All patients with severe signs should be aggressively treated. The use of drugs has not demonstrated a decrease in mortality but a significant reduction in viremia.

  19. A possible link between the Epstein-Barr virus infection and autoimmune thyroid disorders

    Science.gov (United States)

    Gwizdek, Katarzyna; Michalski, Marek; Wojnicz, Romuald

    2016-01-01

    The Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a member of the Herpesviridae virus family. EBV infection can cause infectious mononucleosis (IM) in the lytic phase of EBV’s life cycle. Past EBV infection is associated with lymphomas, and may also result in certain allergic and autoimmune diseases. Although potential mechanisms of autoimmune diseases have not been clearly elucidated, both genetic and environmental factors, such as infectious agents, are considered to be responsible for their development. In addition, EBV modifies the host immune response. The worldwide prevalence of autoimmune diseases shows how common this pathogen is. Normally, the virus stays in the body and remains dormant throughout life. However, this is not always the case, and a serious EBV-related illness may develop later in life. This explains the chronic course of autoimmune diseases that is often accompanied by exacerbations of symptoms. Based on the present studies, EBV infection can cause autoimmune diseases, such as systemic lupus erythematosus (SLE), multiple sclerosis (MS), rheumatoid arthritis (RA), Sjögren’s syndrome, and autoimmune hepatitis. The EBV has also been reported in patients with autoimmune thyroid disorders. Although EBV is not the only agent responsible for the development of autoimmune thyroid diseases, it can be considered a contributory factor. PMID:27833448

  20. Unveiling the transcriptional features associated with coccolithovirus infection of natural Emiliania huxleyi blooms.

    Science.gov (United States)

    Pagarete, António; Le Corguillé, Gildas; Tiwari, Bela; Ogata, Hiroyuki; de Vargas, Colomban; Wilson, William H; Allen, Michael J

    2011-12-01

    Lytic viruses have been implicated in the massive cellular lysis observed during algal blooms, through which they assume a prominent role in oceanic carbon and nutrient flows. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. Here, we employ an oligonucleotide microarray to monitor host (Emiliania huxleyi) and virus (coccolithovirus) transcriptomic features during the course of E. huxleyi blooms induced in seawater-based mesocosm enclosures. Host bloom development and subsequent coccolithovirus infection was associated with a major shift in transcriptional profile. In addition to the expected metabolic requirements typically associated with viral infection (amino acid and nucleotide metabolism, as well as transcription- and replication-associated functions), the results strongly suggest that the manipulation of lipid metabolism plays a fundamental role during host-virus interaction. The results herein reveal the scale, so far massively underestimated, of the transcriptional domination that occurs during coccolithovirus infection in the natural environment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  1. Characterization of Toxoplasma DegP, a rhoptry serine protease crucial for lethal infection in mice.

    Directory of Open Access Journals (Sweden)

    Gaelle Lentini

    Full Text Available During the infection process, Apicomplexa discharge their secretory organelles called micronemes, rhoptries and dense granules to sustain host cell invasion, intracellular replication and to modulate host cell pathways and immune responses. Herein, we describe the Toxoplasma gondii Deg-like serine protein (TgDegP, a rhoptry protein homologous to High temperature requirement A (HtrA or Deg-like family of serine proteases. TgDegP undergoes processing in both types I and II strains as most of the rhoptries proteins. We show that genetic disruption of the degP gene does not impact the parasite lytic cycle in vitro but affects virulence in mice. While in a type I strain DegPI appears dispensable for the establishment of an infection, removal of DegPII in a type II strain dramatically impairs the virulence. Finally, we show that KO-DegPII parasites kill immunodeficient mice as efficiently as the wild-type strain indicating that the protease might be involved in the complex crosstalk that the parasite engaged with the host immune response. Thus, this study unravels a novel rhoptry protein in T. gondii important for the establishment of lethal infection.

  2. Cytoarchitecture of Zika virus infection in human neuroblastoma and Aedes albopictus cell lines.

    Science.gov (United States)

    Offerdahl, Danielle K; Dorward, David W; Hansen, Bryan T; Bloom, Marshall E

    2017-01-15

    The Zika virus (ZIKV) pandemic is a global concern due to its role in the development of congenital anomalies of the central nervous system. This mosquito-borne flavivirus alternates between mammalian and mosquito hosts, but information about the biogenesis of ZIKV is limited. Using a human neuroblastoma cell line (SK-N-SH) and an Aedes albopictus mosquito cell line (C6/36), we characterized ZIKV infection by immunofluorescence, transmission electron microscopy (TEM), and electron tomography (ET) to better understand infection in these disparate host cells. ZIKV replicated well in both cell lines, but infected SK-N-SH cells suffered a lytic crisis. Flaviviruses scavenge host cell membranes to serve as replication platforms and ZIKV showed the hallmarks of this process. Via TEM, we identified virus particles and 60-100nm spherular vesicles. ET revealed these vesicular replication compartments contain smaller 20-30nm spherular structures. Our studies indicate that SK-N-SH and C6/36 cells are relevant models for viral cytoarchitecture study. Published by Elsevier Inc.

  3. Epstein-Barr Virus Lytic Reactivation Activates B Cells Polyclonally and Induces Activation-Induced Cytidine Deaminase Expression: A Mechanism Underlying Autoimmunity and Its Contribution to Graves' Disease.

    Science.gov (United States)

    Nagata, Keiko; Kumata, Keisuke; Nakayama, Yuji; Satoh, Yukio; Sugihara, Hirotsugu; Hara, Sayuri; Matsushita, Michiko; Kuwamoto, Satoshi; Kato, Masako; Murakami, Ichiro; Hayashi, Kazuhiko

    2017-04-01

    Graves' disease is an autoimmune disease that results in and is the most common cause of hyperthyroidism, and the reactivation of persisting Epstein-Barr virus (EBV) in B lymphocytes induces the differentiation of host B cells into plasma cells. We previously reported that some EBV-infected B cells had thyrotropin receptor antibodies (TRAbs) as surface immunoglobulins (Igs), and EBV reactivation induced these TRAb+EBV+ cells to produce TRAbs. EBV reactivation induces Ig production from host B cells. The purpose of the present study was to examine total Ig productions from B cell culture fluids and to detect activation-induced cytidine deaminase (AID), nuclear factor kappa B (NF-κB), and EBV latent membrane protein (LMP) 1 in culture B cells during EBV reactivation induction and then we discussed the mechanisms of EBV reactivation-induced Ig production in relation to autoimmunity. We showed that the EBV reactivation induces the production of every isotype of Ig and suggested that the Ig production was catalyzed by AID through LMP1 and NF-κB. The results that the amount of IgM was significantly larger compared with IgG suggested the polyclonal B cell activation due to LMP1. We proposed the pathway of EBV reactivation induced Ig production; B cells newly infected with EBV are activated by polyclonal B cell activation and produce Igs through plasma cell differentiation induced by EBV reactivation. LMP1-induced AID enabled B cells to undergo class-switch recombination to produce every isotype of Ig. According to this mechanism, EBV rescues autoreactive B cells to produce autoantibodies, which contribute to the development and exacerbation of autoimmune diseases.

  4. Amplification of the Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 lytic origin of DNA replication is dependent upon a cis-acting AT-rich region and an ORF50 response element and the trans-acting factors ORF50 (K-Rta) and K8 (K-bZIP)

    International Nuclear Information System (INIS)

    AuCoin, David P.; Colletti, Kelly S.; Cei, Sylvia A.; Papouskova, Iva; Tarrant, Margaret; Pari, Gregory S.

    2004-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), has significant sequence homology to Epstein-Barr virus (EBV). In cell culture, HHV8 is primarily latent, and viral genes associated with lytic replication are not expressed. Two lytic origins of DNA replication (oriLyt) are present within the HHV8 genome and are composed of an AT-rich region adjacent to GC-rich DNA sequences. We have now identified essential cis- and trans-acting elements required for oriLyt-dependent DNA replication. The transient replication assay was used to show that two AT-rich elements, three consensus AP1 transcription factor-binding sites, an ORF50 response element (RE), and a consensus TATA box motif are essential for efficient origin-dependent DNA replication. Transient transfection of luciferase reporter constructs indicated that the downstream region of the HHV8 oriLyt responds to ORF50 and suggests that part of the oriLyt may be an enhancer/promoter. In addition, a transient cotransfection-replication assay elucidated the set of trans-acting factors required for lytic DNA replication. These factors consist of homologues to the core replication proteins: ORF6 (ssDNA binding protein), ORF9 (DNA polymerase), ORF40-41 (primase-associated factor), ORF44 (helicase), ORF56 (primase), and ORF59 (polymerase processivity factor) common to all herpesviruses along with ORF50 (K-Rta) and K8 (K-bZIP)

  5. The Contribution of Cytomegalovirus Infection to Immune Senescence Is Set by the Infectious Dose

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    Anke Redeker

    2018-01-01

    Full Text Available The relationship between human cytomegalovirus (HCMV infections and accelerated immune senescence is controversial. Whereas some studies reported a CMV-associated impaired capacity to control heterologous infections at old age, other studies could not confirm this. We hypothesized that these discrepancies might relate to the variability in the infectious dose of CMV occurring in real life. Here, we investigated the influence of persistent CMV infection on immune perturbations and specifically addressed the role of the infectious dose on the contribution of CMV to accelerated immune senescence. We show in experimental mouse models that the degree of mouse CMV (MCMV-specific memory CD8+ T cell accumulation and the phenotypic T cell profile are directly influenced by the infectious dose, and data on HCMV-specific T cells indicate a similar connection. Detailed cluster analysis of the memory CD8+ T cell development showed that high-dose infection causes a differentiation pathway that progresses faster throughout the life span of the host, suggesting a virus–host balance that is influenced by aging and infectious dose. Importantly, short-term MCMV infection in adult mice is not disadvantageous for heterologous superinfection with lymphocytic choriomeningitis virus (LCMV. However, following long-term CMV infection the strength of the CD8+ T cell immunity to LCMV superinfection was affected by the initial CMV infectious dose, wherein a high infectious dose was found to be a prerequisite for impaired heterologous immunity. Altogether our results underscore the importance of stratification based on the size and differentiation of the CMV-specific memory T cell pools for the impact on immune senescence, and indicate that reduction of the latent/lytic viral load can be beneficial to diminish CMV-associated immune senescence.

  6. Liposome Entrapment of Bacteriophages Improves Wound Healing in a Diabetic Mouse MRSA Infection

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    Sanjay Chhibber

    2018-03-01

    Full Text Available Diabetic populations are more prone to developing wound infections which results in poor and delayed wound healing. Infection with drug resistant organisms further worsen the situation, driving searches for alternative treatment approaches such as phage therapy. Major drawback of phage therapy, however, is low phage persistence in situ, suggesting further refinement of the approach. In the present work we address this issue by employing liposomes as delivery vehicles. A liposome entrapped phage cocktail was evaluated for its ability to resolve a Staphylococcus aureus-induced diabetic excission wound infection. Two characterized S. aureus specific lytic phages, MR-5 and MR-10 alone, in combination (cocktail, or entrapped in liposomes (versus as free phages were assesed for their therapeutic efficacy in resolving diabetic wound infection. Mice treated with free phage cocktail showed significant reduction in wound bioburden, greater wound contraction and faster tissue healing than with free monophage therapy. However, to further enhance the availability of viable phages the encapsulation of phage cocktail in the liposomes was done. Results of in vitro stability studies and in vivo phage titer determination, suggests that liposomal entrapment of phage cocktail can lead to better phage persistence at the wound site. A 2 log increase in phage titre, however, was observed at the wound site with liposome entrapped as compared to the free phage cocktail, and this was associaed with increased rates of infection resolution and wound healing. Entrapment of phage cocktails within liposomes thus could represent an attractive approach for treatment of bacterial infections, not responding to antibiotis as increased phage persistence in vitro and in vivo at the wound site was observed.

  7. L Particles Transmit Viral Proteins from Herpes Simplex Virus 1-Infected Mature Dendritic Cells to Uninfected Bystander Cells, Inducing CD83 Downmodulation.

    Science.gov (United States)

    Heilingloh, Christiane S; Kummer, Mirko; Mühl-Zürbes, Petra; Drassner, Christina; Daniel, Christoph; Klewer, Monika; Steinkasserer, Alexander

    2015-11-01

    Mature dendritic cells (mDCs) are known as the most potent antigen-presenting cells (APCs) since they are also able to prime/induce naive T cells. Thus, mDCs play a pivotal role during the induction of antiviral immune responses. Remarkably, the cell surface molecule CD83, which was shown to have costimulatory properties, is targeted by herpes simplex virus 1 (HSV-1) for viral immune escape. Infection of mDCs with HSV-1 results in downmodulation of CD83, resulting in reduced T cell stimulation. In this study, we report that not only infected mDCs but also uninfected bystander cells in an infected culture show a significant CD83 reduction. We demonstrate that this effect is independent of phagocytosis and transmissible from infected to uninfected mDCs. The presence of specific viral proteins found in these uninfected bystander cells led to the hypothesis that viral proteins are transferred from infected to uninfected cells via L particles. These L particles are generated during lytic replication in parallel with full virions, called H particles. L particles contain viral proteins but lack the viral capsid and DNA. Therefore, these particles are not infectious but are able to transfer several viral proteins. Incubation of mDCs with L particles indeed reduced CD83 expression on uninfected bystander DCs, providing for the first time evidence that functional viral proteins are transmitted via L particles from infected mDCs to uninfected bystander cells, thereby inducing CD83 downmodulation. HSV-1 has evolved a number of strategies to evade the host's immune system. Among others, HSV-1 infection of mDCs results in an inhibited T cell activation caused by degradation of CD83. Interestingly, CD83 is lost not only from HSV-1-infected mDCs but also from uninfected bystander cells. The release of so-called L particles, which contain several viral proteins but lack capsid and DNA, during infection is a common phenomenon observed among several viruses, such as human

  8. Hantavirus Infections

    Directory of Open Access Journals (Sweden)

    Camilo Guzmán T

    2017-05-01

    Full Text Available Hantaviruses are the causative agents of hantavirus pulmonary syndrome in humans in the Americas; The primary reservoirs are in the rodents of the subfamily Sigmodontinae. In South America, cases of hantavirus pulmonary syndrome caused by numerous viral genotypes have been diagnosed. In Colombia, different serological studies have reported the circulation of hantavirus in humans and rodents. These viruses act in an intimate association with a rodent species that serves as a reservoir and have a distribution around the wild rodent, being limited to a specific geographic region. In South America, the first HPS-associated hantavirus was described in 1993 in Brazil and was called Juquitiva and from 1993 to 2012, more than 1400 cases had been identified in Brazil. This syndrome should be suspected in all patients with respiratory distress syndrome of unclear etiology, in areas endemic for the disease, especially if accompanied by fever, marked leukocytosis and thrombocytopenia and bilateral interstitial infiltrates. Hemorrhagic febrile syndrome has not yet been described in the Americas. There are no clinical or laboratory signs that are pathognomonic of hantavirus infection. The treatment is based on adequate hydration, use of antipyretics and anti-inflammatories and patients with signs of severity should establish a more aggressive management. Triage is indispensable, patients with co-morbidities have a higher mortality risk and therefore should be hospitalized. Future research in Colombia should be directed to multidisciplinary studies that include viral isolation, different clinical forms of case presentation, epidemiological differences, risk factors, and taxonomy of viruses and rodents.

  9. Urinary tract infection - children

    Science.gov (United States)

    UTI - children; Cystitis - children; Bladder infection - children; Kidney infection - children; Pyelonephritis - children ... Craig JC. Long-term antibiotics for preventing recurrent urinary tract infection in children. Cochrane Database Syst Rev . 2011;(3):CD001534. PMID: ...

  10. Infections and Pregnancy

    Science.gov (United States)

    During pregnancy, some common infections like the common cold or a skin infection do not usually cause serious problems. ... of the infections that can be dangerous during pregnancy include Bacterial vaginosis (BV) Group B strep (GBS) ...

  11. Enterobiasis (Pinworm Infection): Treatment

    Science.gov (United States)

    ... The CDC Cancel Submit Search The CDC Parasites - Enterobiasis (also known as Pinworm Infection) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Pinworm Infection General Information Pinworm Infection FAQs Epidemiology & Risk ...

  12. Enterobiasis (Pinworm Infection): Diagnosis

    Science.gov (United States)

    ... The CDC Cancel Submit Search The CDC Parasites - Enterobiasis (also known as Pinworm Infection) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Pinworm Infection General Information Pinworm Infection FAQs Epidemiology & Risk ...

  13. Arcanobacterium Haemolyticum Infections

    Science.gov (United States)

    ... Head Neck & Nervous System Heart Infections Learning Disabilities Obesity ... ) haemolyticum is an organism that most often causes infections and illnesses in teenagers and young adults. The infection is spread from person to person, ...

  14. Viral infection of the marine alga Emiliania huxleyi triggers lipidome remodeling and induces the production of highly saturated triacylglycerol.

    Science.gov (United States)

    Malitsky, Sergey; Ziv, Carmit; Rosenwasser, Shilo; Zheng, Shuning; Schatz, Daniella; Porat, Ziv; Ben-Dor, Shifra; Aharoni, Asaph; Vardi, Assaf

    2016-04-01

    Viruses that infect marine photosynthetic microorganisms are major ecological and evolutionary drivers of microbial food webs, estimated to turn over more than a quarter of the total photosynthetically fixed carbon. Viral infection of the bloom-forming microalga Emiliania huxleyi induces the rapid remodeling of host primary metabolism, targeted towards fatty acid metabolism. We applied a liquid chromatography-mass spectrometry (LC-MS)-based lipidomics approach combined with imaging flow cytometry and gene expression profiling to explore the impact of viral-induced metabolic reprogramming on lipid composition. Lytic viral infection led to remodeling of the cellular lipidome, by predominantly inducing the biosynthesis of highly saturated triacylglycerols (TAGs), coupled with a significant accumulation of neutral lipids within lipid droplets. Furthermore, TAGs were found to be a major component (77%) of the lipidome of isolated virions. Interestingly, viral-induced TAGs were significantly more saturated than TAGs produced under nitrogen starvation. This study highlights TAGs as major products of the viral-induced metabolic reprogramming during the host-virus interaction and indicates a selective mode of membrane recruitment during viral assembly, possibly by budding of the virus from specialized subcellular compartments. These findings provide novel insights into the role of viruses infecting microalgae in regulating metabolism and energy transfer in the marine environment and suggest their possible biotechnological application in biofuel production. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  15. Putative prophages related to lytic tailless marine dsDNA phage PM2 are widespread in the genomes of aquatic bacteria

    Directory of Open Access Journals (Sweden)

    Bamford Dennis H

    2007-07-01

    Full Text Available Abstract Background The origin and evolution of viruses is currently a heavily discussed issue. One element in this discussion is the innate viral "self" concept, which suggests that viral structures and functions can be divided into two categories. The first category consists of genetic determinants that are inherited from a viral ancestor and encode the viral "self". The second group consists of another set of structures and functions, the "nonself", which is interchangeable between different viruses and can be obtained via lateral gene transfer. Comparing the structures and sequences of the "self" elements, we have proposed that viruses can be grouped into lineages regardless of which domain of life (bacteria, archaea, eukarya they infect. It has also been suggested that viruses are ancient and possibly predate modern cells. Results Here we identified thirteen putative prophages (viral genomes integrated into bacterial chromosome closely related to the virulent icosahedral tailless lipid-containing bacteriophage PM2. Using the comparative genomics approach, we present evidence to support the viral "self" hypothesis and divide genes of the bacteriophage PM2 and related prophages into "self" and "nonself" categories. Conclusion We show here that the previously proposed most conserved viral "self" determinants, the major coat protein and the packaging ATPase, were the only proteins that could be recognized in all detected corticoviral elements. We also argue here that the genes needed for viral genome replication, as well as for host cell lysis, belong to the "nonself" category of genes. Furthermore, we suggest that abundance of PM2-like viruses in the aquatic environment as well as their importance in the ecology of aquatic microorganisms might have been underestimated.

  16. Sphingosine kinase-2 maintains viral latency and survival for KSHV-infected endothelial cells.

    Directory of Open Access Journals (Sweden)

    Lu Dai

    Full Text Available Phosphorylation of sphingosine by sphingosine kinases (SphK1 and SphK2 generates sphingosine-1-phosphate (S1P, a bioactive sphingolipid which promotes cancer cell survival and tumor progression in vivo. We have recently reported that targeting SphK2 induces apoptosis for human primary effusion lymphoma (PEL cell lines infected by the Kaposi's sarcoma-associated herpesvirus (KSHV, and this occurs in part through inhibition of canonical NF-κB activation. In contrast, pharmacologic inhibition of SphK2 has minimal impact for uninfected B-cell lines or circulating human B cells from healthy donors. Therefore, we designed additional studies employing primary human endothelial cells to explore mechanisms responsible for the selective death observed for KSHV-infected cells during SphK2 targeting. Using RNA interference and a clinically relevant pharmacologic approach, we have found that targeting SphK2 induces apoptosis selectively for KSHV-infected endothelial cells through induction of viral lytic gene expression. Moreover, this effect occurs through repression of KSHV-microRNAs regulating viral latency and signal transduction, including miR-K12-1 which targets IκBα to facilitate activation of NF-κB, and ectopic expression of miR-K12-1 restores NF-κB activation and viability for KSHV-infected endothelial cells during SphK2 inhibition. These data illuminate a novel survival mechanism and potential therapeutic target for KSHV-infected endothelial cells: SphK2-associated maintenance of viral latency.

  17. What Is Infective Endocarditis?

    Science.gov (United States)

    ANSWERS by heart Cardiovascular Conditions What Is Infective Endocarditis? Infective (bacterial) endocarditis (IE) is an infection of either the heart’s inner lining (endocardium) or the heart valves. Infective endocarditis is a serious — and sometimes fatal — illness. Two ...

  18. Gonococcal Prosthetic Joint Infection.

    Science.gov (United States)

    Gassiep, Ian; Gilpin, Bradley; Douglas, Joel; Siebert, David

    2017-01-01

    Neisseria gonorrhoea is a common sexually transmitted infection worldwide. Disseminated gonococcal infection is an infrequent presentation and rarely can be associated with septic arthritis. Incidence of this infection is rising, both internationally and in older age groups. We present the first documented case of N. gonorrhoea prosthetic joint infection which was successfully treated with laparoscopic debridement and antimicrobial therapy.

  19. Pseudomonal breast infection

    Science.gov (United States)

    Rastall, S; Catchpole, C; Bright-Thomas, R; Thrush, S

    2010-01-01

    Breast infection and breast sepsis secondary to Pseudomonas aeruginosa is uncommon. We report two cases of pseudomonal breast infection leading to septic shock and abscess formation in women with non-responding breast infection. The management of breast infection is broad-spectrum antibiotics and ultrasound with aspiration of any collection. To treat breast infection effectively, the causative organism must be isolated to enable appropriate antibiotic therapy. PMID:20412664

  20. Musculoskeletal infections: ultrasound appearances

    Energy Technology Data Exchange (ETDEWEB)

    Chau, C.L.F. [Department of Radiology, North District Hospital, NTEC, Fanling, NT, Hong Kong (China)]. E-mail: c8681@yahoo.com; Griffith, J.F. [Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, NTEC, Shatin, NT, Hong Kong (China)

    2005-02-01

    Musculoskeletal infections are commonly encountered in clinical practice. This review will discuss the ultrasound appearances of a variety of musculoskeletal infections such as cellulitis, infective tenosynovitis, pyomyositis, soft-tissue abscesses, septic arthritis, acute and chronic osteomyelitis, and post-operative infection. The peculiar sonographic features of less common musculoskeletal infections, such as necrotizing fasciitis, and rice body formation in atypical mycobacterial tenosynovitis, and bursitis will also be presented.

  1. Musculoskeletal infections: ultrasound appearances

    International Nuclear Information System (INIS)

    Chau, C.L.F.; Griffith, J.F.

    2005-01-01

    Musculoskeletal infections are commonly encountered in clinical practice. This review will discuss the ultrasound appearances of a variety of musculoskeletal infections such as cellulitis, infective tenosynovitis, pyomyositis, soft-tissue abscesses, septic arthritis, acute and chronic osteomyelitis, and post-operative infection. The peculiar sonographic features of less common musculoskeletal infections, such as necrotizing fasciitis, and rice body formation in atypical mycobacterial tenosynovitis, and bursitis will also be presented

  2. Shewanella putrefaciens infective endocarditis

    Directory of Open Access Journals (Sweden)

    Jonathan Constant

    2014-11-01

    Full Text Available Shewanella putrefaciens rarely causes infection in humans. In the last few decades a growing number of cases have been described. The following report outlines the case of a 40-year-old immunocompetent white man with S. putrefaciens infective endocarditis. This is the first known case of infective endocarditis due to an apparently monomicrobial S. putrefaciens infection, and the second known case of S. putrefaciens-related infective endocarditis worldwide.

  3. Prosthetic Joint Infections

    Science.gov (United States)

    Aslam, Saima; Darouiche, Rabih O.

    2012-01-01

    Prosthetic joint infections represent a major therapeutic challenge for both healthcare providers and patients. This paper reviews the predisposing factors, pathogenesis, microbiology, diagnosis, treatment and prophylaxis of prosthetic joint infection. The most optimal management strategy should be identified based on a number of considerations including type and duration of infection, antimicrobial susceptibility of the infecting pathogen, condition of infected tissues and bone stock, patient wishes and functional status. PMID:22847032

  4. Seroprevalence and determinants of Kaposi sarcoma-associated human herpesvirus 8 in Indian HIV-infected males.

    Science.gov (United States)

    Munawwar, Arshi; Sharma, Surendra K; Gupta, Somesh; Singh, Sarman

    2014-12-01

    In India Kaposi's sarcoma is rarely seen in AIDS patients. Hence the current belief is that the incidence of human herpesvirus-8 (HHV-8) is very low in this subcontinent, most probably due to the heterosexual route of HIV transmission. However, there is a scarcity of data on the prevalence of HHV-8 in India. In India the primary mode of HIV transmission is the heterosexual route. Therefore we aimed to determine the prevalence of antibodies against HHV-8 in North Indian HIV-infected men naive of antiretroviral therapy (ART). In a prospective study, 165 Indian adult males were recruited from an ART clinic. Blood samples were collected before administering any antiretroviral drug. The sera were tested for antibodies against HHV-8 using a commercial enzyme-linked immunosorbent assay (ELISA) kit, which detects IgG antibodies to lytic antigens of HHV-8. All positive samples were confirmed for the presence of anti-HHV-8 antibodies using an indirect immunofluorescence assay (IFA). The IFA kit is intended to detect primary, latent, persistent, or reactivated infection of HHV-8. Of the 165 males, 43 (26.06%) were positive by ELISA while 26 (15.8%) were also positive by IFA. Seroprevalence decreased with increasing age (p<0.05). Factors independently associated with HHV-8 infection were younger age group and alcohol consumption. These findings suggest that even in a heterosexual population, HHV-8 can be transmitted frequently.

  5. Characterization and complete genome sequence of a novel N4-like bacteriophage, pSb-1 infecting Shigella boydii.

    Science.gov (United States)

    Jun, Jin Woo; Yun, Sae Kil; Kim, Hyoun Joong; Chai, Ji Young; Park, Se Chang

    2014-10-01

    Shigellosis is one of major foodborne pathogens in both developed and developing countries. Although antibiotic therapy is considered an effective treatment for shigellosis, the imprudent use of antibiotics has led to the increase of multiple-antibiotic-resistant Shigella species globally. In this study, we isolated a virulent Podoviridae bacteriophage (phage), pSb-1, that infects Shigella boydii. One-step growth analysis revealed that this phage has a short latent period (15 min) and a large burst size (152.63 PFU/cell), indicating that pSb-1 has good host infectivity and effective lytic activity. The double-stranded DNA genome of pSb-1 is composed of 71,629 bp with a G + C content of 42.74%. The genome encodes 103 putative ORFs, 9 putative promoters, 21 transcriptional terminators, and one tRNA region. Genome sequence analysis of pSb-1 and comparative analysis with the homologous phage EC1-UPM, N4-like phage revealed that there is a high degree of similarity (94%, nucleotide sequence identity) between pSb-1 and EC1-UPM in 73 of the 103 ORFs of pSb-1. The results of this investigation indicate that pSb-1 is a novel virulent N4-like phage infecting S. boydii and that this phage might have potential uses against shigellosis. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. The Role of microRNAs in the Pathogenesis of Herpesvirus Infection.

    Science.gov (United States)

    Piedade, Diogo; Azevedo-Pereira, José Miguel

    2016-06-02

    MicroRNAs (miRNAs) are small non-coding RNAs important in gene regulation. They are able to regulate mRNA translation through base-pair complementarity. Cellular miRNAs have been involved in the regulation of nearly all cellular pathways, and their deregulation has been associated with several diseases such as cancer. Given the importance of microRNAs to cell homeostasis, it is no surprise that viruses have evolved to take advantage of this cellular pathway. Viruses have been reported to be able to encode and express functional viral microRNAs that target both viral and cellular transcripts. Moreover, viral inhibition of key proteins from the microRNA pathway and important changes in cellular microRNA pool have been reported upon viral infection. In addition, viruses have developed multiple mechanisms to avoid being targeted by cellular microRNAs. This complex interaction between host and viruses to control the microRNA pathway usually favors viral infection and persistence by either reducing immune detection, avoiding apoptosis, promoting cell growth, or promoting lytic or latent infection. One of the best examples of this virus-host-microRNA interplay emanates from members of the Herperviridae family, namely the herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2), human cytomegalovirus (HCMV), human herpesvirus 8 (HHV-8), and the Epstein-Barr virus (EBV). In this review, we will focus on the general functions of microRNAs and the interactions between herpesviruses, human hosts, and microRNAs and will delve into the related mechanisms that contribute to infection and pathogenesis.

  7. Vaginal yeast infection

    Science.gov (United States)

    Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts ...

  8. Salmonella Infections - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Salmonella Infections URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Salmonella Infections - Multiple Languages To use the sharing features ...

  9. Blastocytosis hominis Infection

    Science.gov (United States)

    ... increases in places with inadequate sanitation and poor personal hygiene. Risk factors Blastocystis is common, and anyone can ... you have blastocystis or another gastrointestinal infection, good personal hygiene can help keep you from spreading the infection ...

  10. Cancer treatment - preventing infection

    Science.gov (United States)

    ... Radiation - preventing infection; Bone marrow transplant - preventing infection; Cancer treatment - immunosuppression ... this is a short-lived side effect of cancer treatment. Your provider may give you medicines to help ...

  11. Fungal Skin Infections

    Science.gov (United States)

    ... Abbreviations Weights & Measures ENGLISH View Professional English Deutsch Japanese Espaniol Find information on medical topics, symptoms, drugs, ... touching the infected area. Diagnosis Skin scrapings or cultures Doctors may suspect a fungal infection when they ...

  12. Infection After Hysterectomy

    Directory of Open Access Journals (Sweden)

    David L. Hemsell

    1997-01-01

    Full Text Available Antibiotic prophylaxis and advances in technology have reduced operative site infections after hysterectomy to a minimum. Pelvic infections are the most common infection type and respond promptly to a variety of parenteral single-agent and combination antibiotic regimens. Oral antibiotic regimens following parenteral therapy are unnecessary. Abdominal incision infections are less common than pelvic infections, less common than seromas or hematomas, and usually do not require antimicrobial therapy. Abscesses or infected hematomas require parenteral antimicrobial therapy, and drainage of those located above the cuff will predictably shorten therapy time. With early discharge from the hospital, many infections will not become evident until after the patient is home. For that reason, it is important that the patient's discharge instructions outline symptoms and signs associated with these infections so she can present for care at the earliest possible time.

  13. Ear Infection and Vaccines

    Science.gov (United States)

    ... an ENT Doctor Near You Ear Infection and Vaccines Ear Infection and Vaccines Patient Health Information News ... or may need reinsertion over time. What about vaccines? A vaccine is a preparation administered to stimulate ...

  14. C. difficile Infection

    Science.gov (United States)

    ... Patients Home / Digestive Health Topic / C. Difficile Infection C. Difficile Infection Basics Overview Diarrhea is a frequent ... that change the normal colon bacteria allowing the C. difficile bacteria to grow and produce its toxins. ...

  15. Rotavirus Infections - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Rotavirus Infections URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Rotavirus Infections - Multiple Languages To use the sharing features ...

  16. Urinary tract infection - adults

    Science.gov (United States)

    Bladder infection - adults; UTI - adults; Cystitis - bacterial - adults; Pyelonephritis - adults; Kidney infection - adults ... control. Menopause also increases the risk of a UTI. The following also increase your chances of developing ...

  17. Enterococcus faecalis infective endocarditis

    DEFF Research Database (Denmark)

    Dahl, Anders; Bruun, Niels Eske

    2013-01-01

    Enterococcus faecalis infective endocarditis (IE) is a disease of increasing importance, with more patients infected, increasing frequency of health-care associated infections and increasing incidence of antimicrobial resistances. The typical clinical presentation is a subacute course with fever...... or ceftriaxone. E. faecalis infective endocarditis continues to be a very serious disease with considerable percentages of high-level gentamicin resistant strains and in-hospital mortality around 20%. Strategies to prevent E. faecalis IE, improve diagnostics, optimize treatment and reduce morbidity...

  18. Infections following epidural catheterization

    DEFF Research Database (Denmark)

    Holt, MS; Andersen, SS; Andersen, Ove

    1995-01-01

    of central nervous system infection of at least 0.7% at Odense University Hospital. This degree of infection is of the same magnitude as that reported for intravascular devices. We found that the patients with generalized symptoms of infection had been catheterized for a longer time, and were older than...

  19. Enterococcus faecalis infective endocarditis

    DEFF Research Database (Denmark)

    Dahl, Anders; Rasmussen, Rasmus V; Bundgaard, Henning

    2013-01-01

    Because of the nephrotoxic effects of aminoglycosides, the Danish guidelines on infective endocarditis were changed in January 2007, reducing gentamicin treatment in enterococcal infective endocarditis from 4 to 6 weeks to only 2 weeks. In this pilot study, we compare outcomes in patients...... with Enterococcus faecalis infective endocarditis treated in the years before and after endorsement of these new recommendations....

  20. Brucella Infection in HIV Infected Patients

    Directory of Open Access Journals (Sweden)

    SeyedAhmad SeyedAlinaghi

    2011-12-01

    Full Text Available The purpose of this study was to assess the possible correlation between Brucella and HIV infections. Iran is a country where HIV infection is expanding and Brucellosis is prevalent. In the present study, 184 HIV infected patients were assigned and for all of them HIV infection was confirmed by western blot test. In order to identify the prevalence rate of Brucella infection and systemic brucellosis in these subjects, sera samples were obtained and Brucella specific serological tests were performed to reveal antibody titers. Detailed history was taken and physical examination was carried out for all of patients. 11 (6% subjects had high titers but only 3 of them were symptomatic. Most of these subjects were injection drug user (IDU men and one was a rural woman. Considering both prevalence rates of Brucella infection (3% and symptomatic brucellosis (0.1% in Iran, our HIV positive patients show higher rates of Brucella infection and systemic brucellosis. Preserved cellular immunity of participants and retention of granulocytes activity may explain this poor association; whereas other explanations such as immunological state difference and non-overlapping geographical distribution of the 2 pathogens have been mentioned by various authors.

  1. Bacteriophage T4 Infection of Stationary Phase E. coli: Life after Log from a Phage Perspective

    Directory of Open Access Journals (Sweden)

    Elizabeth Martin Kutter

    2016-09-01

    Full Text Available Virtually all studies of phage infections investigate bacteria growing exponentially in rich media. In nature, however, phages largely encounter non-growing cells. Bacteria entering stationary phase often activate well-studied stress defense mechanisms that drastically alter the cell, facilitating its long-term survival. An understanding of phage-host interactions in such conditions is of major importance from both an ecological and therapeutic standpoint. Here, we show that bacteriophage T4 can efficiently bind to, infect and kill E. coli in stationary phase, both in the presence and absence of a functional stationary-phase sigma factor, and explore the response of T4-infected stationary phase cells to the addition of fresh nutrients 5 or 24 hours after that infection. An unexpected new mode of response has been identified. Hibernation mode is a persistent but reversible dormant state in which the infected cells make at least some phage enzymes, but halt phage development until appropriate nutrients become available before producing phage particles. Our evidence indicates that the block in hibernation mode occurs after the middle-mode stage of phage development; host DNA breakdown and the incorporation of the released nucleotides into phage DNA indicate that the enzymes of the nucleotide synthesizing complex, under middle-mode control, have been made and assembled into a functional state. Once fresh glucose and amino acids become available, the standard lytic infection process rapidly resumes and concentrations of up to 1011 progeny phage (an average of about 40 phage per initially-present cell are produced. All evidence is consistent with the hibernation-mode control point lying between middle mode and late mode T4 gene expression. We have also observed a scavenger response, where the infecting phage takes advantage of whatever few nutrients are available to produce small quantities of progeny within 2 to 5 hours after infection. The scavenger

  2. Cytomegalovirus infection in pregnancy.

    Science.gov (United States)

    Kagan, Karl Oliver; Hamprecht, Klaus

    2017-07-01

    Due to the severe risk of long-term sequelae, prenatal cytomegalovirus infection is of particular importance amongst intrauterine viral infections. This review summarizes the current knowledge about CMV infection in pregnancy. A search of the Medline and Embase database was done for articles about CMV infection in pregnany. We performed a detailed review of the literature in view of diagnosis, epidemiology and management of CMV infection in pregnancy. The maternal course of the infection is predominantly asymptomatic; the infection often remains unrecognized until the actual fetal manifestation. Typical ultrasound signs that should arouse suspicion of intrauterine CMV infection can be distinguished into CNS signs such as ventriculomegaly or microcephaly and extracerebral infection signs such as hepatosplenomegaly or hyperechogenic bowel. Current treatment strategies focus on hygienic measures to prevent a maternal CMV infection during pregnancy, on maternal application of hyperimmunoglobulines to avoid materno-fetal transmission in case of a maternal seroconversion, and on an antiviral therapy in case the materno-fetal transmission have occurred. CMV infection in pregnancy may result in a severe developmental disorder of the newborn. This should be taken into account in the treatment of affected and non-affected pregnant women.

  3. Zika virus infection of cellular components of the blood-retinal barriers: implications for viral associated congenital ocular disease.

    Science.gov (United States)

    Roach, Tracoyia; Alcendor, Donald J

    2017-03-03

    1), and vascular cell adhesion molecule 1 (VCAM-1) and higher levels of regulated upon activation, normal T cell expressed and presumably secreted (RANTES) but lower levels of interleukin-4 (IL-4) compared to controls. Retinal endothelial cells, retinal pericytes, and retinal pigmented epithelial cells are fully permissive for ZIKV lytic replication and are primary target cells in the retinal barriers for infection. ZIKV infection of retinal endothelial cells and retinal pericytes induces significantly higher levels of RANTES that likely contributes to ocular inflammation.

  4. Twenty putative palmitoyl-acyl transferase genes with distinct ...

    African Journals Online (AJOL)

    There are 20 genes containing DHHC domain predicted to encode putative palmitoyltransferase in Arabidopsis thaliana genome. However, little is known about their characteristics such as genetic relationship and expression profile. Here, we present an overview of the putative PAT genes in A. thaliana focusing on their ...

  5. Fenofibrate Therapy in Carnitine Palmitoyl Transferase Type 2 Deficiency

    Directory of Open Access Journals (Sweden)

    I. Hamilton-Craig

    2012-01-01

    Full Text Available Bezafibrate therapy has been shown to improve beta-oxidation of fatty acids and to reduce episodes of rhabdomyolysis in patients with carnitine palmitoyltransferase type-2 (CPT2 deficiency. We report the efficacy of fenofibrate in a patient with CPT2 deficiency, in whom beta-oxidation was improved but an episode of rhabdomyolysis nevertheless occurred. This suggests additional methods to avoid rhabdomyolysis in patients with CPT2 deficiency should accompany fibrate therapy, including avoidance of muscular overexertion, dehydration, and heat exposure.

  6. Imaging of hepatic infections

    International Nuclear Information System (INIS)

    Doyle, D.J.; Hanbidge, A.E.; O'Malley, M.E.

    2006-01-01

    Imaging plays a significant role in the detection, characterization and treatment of hepatic infections. Infectious diseases of the liver include pyogenic and amoebic abscesses and parasitic, fungal, viral and granulomatous infections. With increases in worldwide travel, immunosuppression and changing population demographics, identification of cases of hepatic infection is becoming more common in daily practice. Knowledge of the imaging features seen with hepatic infections can assist in early diagnosis and timely initiation of appropriate therapy. This review presents the imaging appearances of hepatic infections, emphasizing specific features that may contribute to the diagnosis. Examples of the imaging findings seen with pyogenic and amoebic abscesses, infection with Echinococcus granulosus (Hydatid), schistosomiasis, candidiasis and tuberculosis (TB) are presented

  7. Imaging of hepatic infections

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, D.J. [Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ont. (Canada)]. E-mail: doyledj@hotmail.com; Hanbidge, A.E. [Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ont. (Canada); O' Malley, M.E. [Department of Medical Imaging, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Ont. (Canada)

    2006-09-15

    Imaging plays a significant role in the detection, characterization and treatment of hepatic infections. Infectious diseases of the liver include pyogenic and amoebic abscesses and parasitic, fungal, viral and granulomatous infections. With increases in worldwide travel, immunosuppression and changing population demographics, identification of cases of hepatic infection is becoming more common in daily practice. Knowledge of the imaging features seen with hepatic infections can assist in early diagnosis and timely initiation of appropriate therapy. This review presents the imaging appearances of hepatic infections, emphasizing specific features that may contribute to the diagnosis. Examples of the imaging findings seen with pyogenic and amoebic abscesses, infection with Echinococcus granulosus (Hydatid), schistosomiasis, candidiasis and tuberculosis (TB) are presented.

  8. Prevalence of antibodies to human herpesvirus-8 in populations with and without risk for infection in São Paulo State

    Directory of Open Access Journals (Sweden)

    Souza V.A.U.F.

    2004-01-01

    Full Text Available Human herpesvirus 8 (HHV-8 is a newly described herpesvirus that is etiologically associated with all forms of Kaposi's sarcoma (KS. Seroepidemiological studies have shown high prevalence rates of HHV-8 antibodies among men who have sex with men (MSM and AIDS patients, African children, Brazilian Amerindians, and elderly individuals in certain regions of Europe. The aim of the present study was to determine the prevalence of HHV-8 antibodies in healthy children and young adults from different cities in São Paulo State, and in a population at high risk for HHV-8 infection: HIV-negative MSM, and AIDS patients with and without KS. Antibodies to HHV-8 latency-associated nuclear antigen and lytic-phase antigens were detected by immunofluorescence assays. In 643 healthy children and young adults from the general population attending a vaccination program for yellow fever in ten different cities in São Paulo State, the prevalence of HHV-8 antibodies detected by the presence of latent or lytic antigens ranged from 1.0 to 4.1% in the different age groups (mean = 2.5%. In the MSM group, the prevalence was 31/95 (32.6%. In the group of patients with AIDS, the prevalence was 39.2% (51/130 for non-KS patients and 98.7% (77/78 for AIDS patients with the diagnosis of KS confirmed by histopathological examination. We conclude that HHV-8 has a restricted circulation among healthy children and young adults in the general population of São Paulo State and a high prevalence among MSM and AIDS patients.

  9. Pregnancy and HIV infection

    OpenAIRE

    Mete Sucu; Cihan Cetin; Mehmet Ozsurmeli; Ghanim Khatib; Ceren Cetin; Cuneyt Evruke

    2016-01-01

    The management of Human Immunodeficiency Virus (HIV) infection is progressing rapidly. In developed countries, the perinatal transmission rates have decreased from 20-30% to 1-2% with the use of antiretroviral therapy and cesarean section. Interventions for the prevention of prenatal transmission has made the prenatal care of pregnant patients with HIV infection more complex. Rapid development of standard care and continuing increase in the distribution of HIV infection has required clinician...

  10. Paediatric HIV infection.

    Science.gov (United States)

    Scarlatti, G

    1996-09-28

    By the year 2000 there will be six million pregnant women and five to ten million children infected with HIV-1. Intervention strategies have been planned and in some instances already started. A timely and cost-effective strategy needs to take into account that most HIV-1 infected individuals reside in developing countries. Further studies are needed on immunological and virological factors affecting HIV-1 transmission from mother to child, on differential disease progression in affected children, and on transient infection.

  11. Imaging of Periprosthetic Infection.

    LENUS (Irish Health Repository)

    Carty, Fiona

    2013-05-22

    Periprosthetic infection is one of the most challenging and difficult complications in orthopaedics. It can result in significant patient distress and disability, with repeated surgeries, increased cost and utilization of medical resources, and in rare cases even mortality. The biggest challenge to date is the correct diagnosis of periprosthetic infection and implementation of effective treatment regimens capable of eradicating the organism. This article reviews the various modalities used in the imaging of periprosthetic and post-arthroplasty infection.

  12. Freshwater Fungal Infections

    Directory of Open Access Journals (Sweden)

    Dennis J. Baumgardner

    2017-01-01

    Full Text Available Fungal infections as a result of freshwater exposure or trauma are fortunately rare. Etiologic agents are varied, but commonly include filamentous fungi and Candida. This narrative review describes various sources of potential freshwater fungal exposure and the diseases that may result, including fungal keratitis, acute otitis externa and tinea pedis, as well as rare deep soft tissue or bone infections and pulmonary or central nervous system infections following traumatic freshwater exposure during natural disasters or near-drowning episodes. Fungal etiology should be suspected in appropriate scenarios when bacterial cultures or molecular tests are normal or when the infection worsens or fails to resolve with appropriate antibacterial therapy.

  13. Congenital cytomegalovirus infection

    Directory of Open Access Journals (Sweden)

    Katarina Rednak-Paradiž

    2006-11-01

    Full Text Available Background: CMV is the most common agent that causes congenital virus infection. Only 10 % of infected children have symptomatic infection immediately after birth. Signs of central nervous system damage, neurosensory deafness and delayed psychomotor development may manifest as a result of asimptomatic congenital infection later in childhood. In the article we present basic properties of CMV; we describe clinical picture of the congenital infection and possibilities of diagnose and its treatment. We present five children with symptomatic congenital CMV infection that were hospitalized for the period 1992–2002 at the Neonatal department in the University Children’s Hospital in Ljubljana.Conclusions: Identification of infected neonates, especially those with asimptomatic congenital CMV infection, is difficult. Latest incidence of infection in Slovenia is unknown. With new investigations the efficiency of antiviral therapy was discovered but exact indications for therapy are not yet known. CMV vaccine, once available, may ultimately be the best control strategy for this important public health problem. Proper educating women in childbearing age about the risks of CMV and how to avoid disease transmission during pregnancy (hand washing, avoiding mouth-to-mouth contact with preschool children, usage of gloves especially when handling dipers or respiratory secretions are the only control strategies available.

  14. Pets and Pasteurella Infections

    Science.gov (United States)

    ... present in some children, including an infection of the joints ( arthritis ), bones (osteomyelitis), and tendons (tenosynovitis). Less frequently, youngsters may have pneumonia , urinary tract ...

  15. [ZIKA--VIRUS INFECTION].

    Science.gov (United States)

    Velev, V

    2016-01-01

    This review summarizes the knowledge of the scientific community for Zika-virus infection. It became popular because of severe congenital damage causes of CNS in newborns whose mothers are infected during pregnancy, as well as the risk of pandemic distribution. Discusses the peculiarities of the biology and ecology of vectors--blood-sucking mosquitoes Aedes; stages in the spread of infection and practical problems which caused during pregnancy. Attention is paid to the recommendations that allow leading national and international medical organizations to deal with the threat Zika-virus infection.

  16. Who Gets Fungal Infections?

    Science.gov (United States)

    ... Testing Treatment & Outcomes Health Professionals Statistics More Resources Candidiasis Candida infections of the mouth, throat, and esophagus Vaginal candidiasis Invasive candidiasis Definition Symptoms Risk & Prevention Sources Diagnosis ...

  17. Lower expression of CADM1 and higher expression of MAL in Merkel cell carcinomas are associated with Merkel cell polyomavirus infection and better prognosis.

    Science.gov (United States)

    Iwasaki, Takeshi; Matsushita, Michiko; Nonaka, Daisuke; Nagata, Keiko; Kato, Masako; Kuwamoto, Satoshi; Murakami, Ichiro; Hayashi, Kazuhiko

    2016-02-01

    Merkel cell carcinoma (MCC) is a clinically aggressive neuroendocrine skin cancer; 80% of the cases are associated with the Merkel cell polyomavirus (MCPyV). We previously reported that MCPyV-negative MCCs have more irregular nuclei with abundant cytoplasm and significantly unfavorable outcomes than do MCPyV-positive MCCs. These results suggest that some cell adhesion or structural stabilization molecules are differently expressed depending on MCPyV infection status. Thus, we investigated the association of prognosis or MCPyV infection status in MCCs with cell adhesion molecule 1 (CADM1)/differentially expressed in adenocarcinoma of the lung protein 1 (DAL-1)/membrane protein, palmitoylated 3 (MPP3) tripartite complex and mal T-cell differentiation protein (MAL) expression, which play important roles in cell adhesion and oncogenesis and are related to cancer outcomes in various malignancies, to elucidate the role of these molecules. We analyzed the pathological and molecular characteristics of 26 MCPyV-positive and 15 MCPyV-negative MCCs. Univariate Cox regression analysis showed that advanced age (hazard ratio [HR], 8.249; P = .007) and high CADM1 expression (HR, 5.214; P = .012) were significantly unfavorable overall survival parameters, whereas MCPyV infection (HR, 0.043, P Merkel cells expressed DAL-1 and MAL but not CADM1. This study revealed that MCPyV-negative MCCs significantly expressed higher CADM1 and lower MAL than MCPyV-positive MCCs; these expression levels were markedly related to unfavorable outcomes. These data will give us important insights to develop novel molecular target therapies for MCCs. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A naturally derived gastric cancer cell line shows latency I Epstein-Barr virus infection closely resembling EBV-associated gastric cancer

    International Nuclear Information System (INIS)

    Oh, Sang Taek; Seo, Jung Seon; Moon, Uk Yeol; Kang, Kyeong Hee; Shin, Dong-Jik; Yoon, Sungjoo Kim; Kim, Woo Ho; Park, Jae-Gahb; Lee, Suk Kyeong

    2004-01-01

    In a process seeking out a good model cell line for Epstein-Barr virus (EBV)-associated gastric cancer, we found that one previously established gastric adenocarcinoma cell line is infected with type 1 EBV. This SNU-719 cell line from a Korean patient expressed cytokeratin without CD19 or CD21 expression. In SNU-719, EBNA1 and LMP2A were expressed, while LMP1 and EBNA2 were not. None of the tested lytic EBV proteins were detected in this cell line unless stimulated with phorbol ester. EBV infection was also shown in the original carcinoma tissue of SNU-719 cell line. Our results support the possibility of a CD21-independent EBV infection of gastric epithelial cells in vivo. As the latent EBV gene expression pattern of SNU-719 closely resembles that of the EBV-associated gastric cancer, this naturally derived cell line may serve as a valuable model system to clarify the precise role of EBV in gastric carcinogenesis

  19. JC polyomavirus infection is strongly controlled by human leucocyte antigen class II variants.

    Directory of Open Access Journals (Sweden)

    Emilie Sundqvist

    2014-04-01

    Full Text Available JC polyomavirus (JCV carriers with a compromised immune system, such as in HIV, or subjects on immune-modulating therapies, such as anti VLA-4 therapy may develop progressive multifocal leukoencephalopathy (PML which is a lytic infection of oligodendrocytes in the brain. Serum antibodies to JCV mark infection occur only in 50-60% of infected individuals, and high JCV-antibody titers seem to increase the risk of developing PML. We here investigated the role of human leukocyte antigen (HLA, instrumental in immune defense in JCV antibody response. Anti-JCV antibody status, as a surrogate for JCV infection, were compared to HLA class I and II alleles in 1621 Scandinavian persons with MS and 1064 population-based Swedish controls and associations were replicated in 718 German persons with MS. HLA-alleles were determined by SNP imputation, sequence specific (SSP kits and a reverse PCR sequence-specific oligonucleotide (PCR-SSO method. An initial GWAS screen displayed a strong HLA class II region signal. The HLA-DRB1*15 haplotype was strongly negatively associated to JCV sero-status in Scandinavian MS cases (OR = 0.42, p = 7×10(-15 and controls (OR = 0.53, p = 2×10(-5. In contrast, the DQB1*06:03 haplotype was positively associated with JCV sero-status, in Scandinavian MS cases (OR = 1.63, p = 0.006, and controls (OR = 2.69, p = 1×10(-5. The German dataset confirmed these findings (OR = 0.54, p = 1×10(-4 and OR = 1.58, p = 0.03 respectively for these haplotypes. HLA class II restricted immune responses, and hence CD4+ T cell immunity is pivotal for JCV infection control. Alleles within the HLA-DR1*15 haplotype are associated with a protective effect on JCV infection. Alleles within the DQB1*06:03 haplotype show an opposite association. These associations between JC virus antibody response and human leucocyte antigens supports the notion that CD4+ T cells are crucial in the immune defence to JCV and

  20. [Emergent viral infections

    NARCIS (Netherlands)

    Galama, J.M.D.

    2001-01-01

    The emergence and re-emergence of viral infections is an ongoing process. Large-scale vaccination programmes led to the eradication or control of some viral infections in the last century, but new viruses are always emerging. Increased travel is leading to a rise in the importation of exotic

  1. Surgical infections with Mycoplasma

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Prag, Jørgen Brorson; Jensen, J S

    1997-01-01

    Mycoplasma hominis and Ureaplasma urealyticum are common inhabitants of the human genital tract. Evidence for an aetiological role in pyelonephritis, pelvic inflammatory disease, post-abortion and post-partum fever has been presented. There are sporadic reports of Mycoplasma causing serious...... extragenital infection such as septicemia, septic arthritis, neonatal meningitis and encephalitis. We review 38 cases of surgical infections with Mycoplasma....

  2. Neglected Parasitic Infections: Toxocariasis

    Centers for Disease Control (CDC) Podcasts

    This podcast is an overview of the Clinician Outreach and Communication Activity (COCA) Call: Neglected Parasitic Infections in the United States. Neglected Parasitic Infections are a group of diseases that afflict vulnerable populations and are often not well studied or diagnosed. A subject matter expert from CDC's Division of Parasitic Diseases and Malaria describes the epidemiology, diagnosis, and treatment of toxocariasis.

  3. Nocardia infection following phacoemulsification

    Directory of Open Access Journals (Sweden)

    Gokhale Nikhil

    2007-01-01

    Full Text Available Infection of a self-sealing tunnel incision is a rare but vision-threatening complication of cataract surgery. We describe two cases of side port infection following an uneventful phacoemulsification. Nocardia was isolated in one case. Both the cases were worsening on medical treatment and were successfully treated by therapeutic keratoplasty.

  4. Pulmonary infections after tuberculosis

    Directory of Open Access Journals (Sweden)

    Kauser Jabeen

    2016-01-01

    Conclusion: Limited diagnostic and therapeutic capacities compounded by nonavailability of essential antimicrobials in most high-TB-burden countries pose great challenges to physicians involved in the management of these infections. These infections affect the overall outcome and lead to high cost for public health systems.

  5. Human Adenovirus Infection Causes Cellular E3 Ubiquitin Ligase MKRN1 Degradation Involving the Viral Core Protein pVII.

    Science.gov (United States)

    Inturi, Raviteja; Mun, Kwangchol; Singethan, Katrin; Schreiner, Sabrina; Punga, Tanel

    2018-02-01

    Human adenoviruses (HAdVs) are common human pathogens encoding a highly abundant histone-like core protein, VII, which is involved in nuclear delivery and protection of viral DNA as well as in sequestering immune danger signals in infected cells. The molecular details of how protein VII acts as a multifunctional protein have remained to a large extent enigmatic. Here we report the identification of several cellular proteins interacting with the precursor pVII protein. We show that the cellular E3 ubiquitin ligase MKRN1 is a novel precursor pVII-interacting protein in HAdV-C5-infected cells. Surprisingly, the endogenous MKRN1 protein underwent proteasomal degradation during the late phase of HAdV-C5 infection in various human cell lines. MKRN1 protein degradation occurred independently of the HAdV E1B55K and E4orf6 proteins. We provide experimental evidence that the precursor pVII protein binding enhances MKRN1 self-ubiquitination, whereas the processed mature VII protein is deficient in this function. Based on these data, we propose that the pVII protein binding promotes MKRN1 self-ubiquitination, followed by proteasomal degradation of the MKRN1 protein, in HAdV-C5-infected cells. In addition, we show that measles virus and vesicular stomatitis virus infections reduce the MKRN1 protein accumulation in the recipient cells. Taken together, our results expand the functional repertoire of the HAdV-C5 precursor pVII protein in lytic virus infection and highlight MKRN1 as a potential common target during different virus infections. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing a wide range of diseases. To achieve pathogenicity, HAdVs have to counteract a variety of host cell antiviral defense systems, which would otherwise hamper virus replication. In this study, we show that the HAdV-C5 histone-like core protein pVII binds to and promotes self-ubiquitination of a cellular E3 ubiquitin ligase named MKRN1. This mutual interaction between the pVII and

  6. Association of GATA2 Deficiency With Severe Primary Epstein-Barr Virus (EBV) Infection and EBV-associated Cancers.

    Science.gov (United States)

    Cohen, Jeffrey I; Dropulic, Lesia; Hsu, Amy P; Zerbe, Christa S; Krogmann, Tammy; Dowdell, Kennichi; Hornung, Ronald L; Lovell, Jana; Hardy, Nancy; Hickstein, Dennis; Cowen, Edward W; Calvo, Katherine R; Pittaluga, Stefania; Holland, Steven M

    2016-07-01

    Most patients infected with Epstein-Barr virus (EBV) are asymptomatic, have nonspecific symptoms, or have self-limiting infectious mononucleosis. EBV, however, may result in severe primary disease or cancer. We report EBV diseases associated with GATA2 deficiency at one institution and describe the hematology, virology, and cytokine findings. Seven patients with GATA2 deficiency developed severe EBV disease. Three presented with EBV infectious mononucleosis requiring hospitalization, 1 had chronic active EBV disease (B-cell type), 1 had EBV-associated hydroa vacciniforme-like lymphoma with hemophagocytic lymphohistiocytosis, and 2 had EBV-positive smooth muscle tumors. Four of the 7 patients had severe warts and 3 had disseminated nontuberculous mycobacterial infections. All of the patients had low numbers of monocytes, B cells, CD4 T cells, and natural killer cells. All had elevated levels of EBV in the blood; 2 of 3 patients tested had expression of the EBV major immediate-early gene in the blood indicative of active EBV lytic infection. Mean plasma levels of tumor necrosis factor α, interferon γ, and interferon gamma-induced protein 10 were higher in patients with GATA2 deficiency than in controls. GATA2 is the first gene associated with EBV hydroa vacciniforme-like lymphoma. GATA2 deficiency should be considered in patients with severe primary EBV infection or EBV-associated cancer, especially in those with disseminated nontuberculous mycobacterial disease and warts. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  7. Key aspects congenital infection

    Directory of Open Access Journals (Sweden)

    Yu. V. Lobzin

    2014-01-01

    Full Text Available The key questions to solve the problem of congenital infection in the Russian Federation are: using in national practice over world accepted terminology adapted to the recommendations of the World Health Organization; representation of the modern concepts of an infectious process in the classification of congenital infections; scientific development and introducing in clinical practice the «standard case definitions», applied to different congenital infections; optimization of protocols and clinical guidelines for diagnosis, treatment and prevention of congenital infections; improvement a knowledge in the infectious disease for all  pecialists involved in the risk assessment of congenital infections, manage pregnancy and children. Based on our experience and analysis of publications, the authors suggest possible solutions.

  8. Bladder Infection (Urinary Tract Infection - UTI) in Adults

    Science.gov (United States)

    ... The Urinary Tract & How It Works Bladder Infection (Urinary Tract Infection—UTI) in Adults View or Print All ... Bladder infections are the most common type of urinary tract infection (UTI), but any part of your urinary ...

  9. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA Mediated Orthopaedic Device Related Infections.

    Directory of Open Access Journals (Sweden)

    Sandeep Kaur

    Full Text Available Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA, treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA. Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection.

  10. Enhancement of innate immunity with granulocyte colony-stimulating factor did not mitigate disease in pigs infected with a highly pathogenic Chinese PRRSV strain.

    Science.gov (United States)

    Schlink, Sarah N; Lager, Kelly M; Brockmeier, Susan L; Loving, Crystal L; Miller, Laura C; Vorwald, Ann C; Yang, Han-Chun; Kehrli, Marcus E; Faaberg, Kay S

    2016-10-15

    Porcine reproductive and respiratory syndrome virus (PRRSV) is responsible for one of the most economically important diseases in swine worldwide. It causes reproductive failure in sows and pneumonia in pigs that predisposes them to secondary bacterial infections. Methods to control PRRSV and/or limit secondary bacterial infections are desired to reduce the impact of this virus on animal health. Neutrophils play a major role in combatting infection; they can act as phagocytes as well as produce and release lytic enzymes that have potent antimicrobial effects leading to the destruction and clearance of bacterial pathogens. Granulocyte-colony stimulating factor (G-CSF) is a cytokine that controls the production, differentiation and function of granulocytes (including neutrophils) from the bone marrow. Recent work from our laboratory has shown that encoding porcine G-CSF in a replication-defective adenovirus (Ad5-G-CSF) and delivering a single dose to pigs induced a neutrophilia lasting more than two weeks. As secondary bacterial infection is a common occurrence following PRRSV infection, particularly following challenge with highly pathogenic (HP)-PRRSV, the aim of the current study was to evaluate the effectiveness of a single prophylactic dose of adenovirus-encoded G-CSF to mitigate secondary bacterial disease associated with HP-PRRSV infection. Administration of Ad5-G-CSF induced a significant neutrophilia as expected. However, between 1 and 2days following HP-PRRSV challenge the number of circulating neutrophils decreased dramatically in the HP-PRRSV infected group, but not the non-infected Ad5-G-CSF group. Ad5-G-CSF administration induced monocytosis as well, which was also reduced by HP-PRRSV challenge. There was no difference in the progression of disease between the Ad5-G-CSF and Ad5-empty groups following HP-PRRSV challenge, with pneumonia and systemic bacterial infection occurring in both treatment groups. Given the impact of HP-PRRSV infection on the

  11. Candida infection of the skin

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000880.htm Candida infection of the skin To use the sharing features on this page, please enable JavaScript. Candida infection of the skin is a yeast infection ...

  12. HPV Infection in Men

    Directory of Open Access Journals (Sweden)

    Joel M. Palefsky

    2007-01-01

    Full Text Available While much is known about the natural history of cervical human papillomavirus (HPV infection and its consequences, including cervical intraepithelial neoplasia and cervical cancer, relatively little is known about the natural history of anogenital HPV infection and diseases in men. In part this reflects difficulties in penile sampling and visual assessment of penile lesions. Anal HPV infection and disease also remain poorly understood. Although HPV is transmitted sexually and infects the genitals of both sexes, the cervix remains biologically more vulnerable to malignant transformation than does the penis or anus in men. An understanding of male HPV infection is therefore important in terms of reducing transmission of HPV to women and improving women's health. However, it is also important due to the burden of disease in men, who may develop both penile and anal cancer, particularly among HIV-positive men who have sex with men. Improved sampling techniques of the male genitalia and cohort studies in progress should provide important information on the natural history of anogenital HPV infection and disease in men, including risk factors for HPV acquisition and transmission. The impact of HPV vaccination in women on male anogenital HPV infection will also need to be assessed.

  13. Pregnancy and Toxoplasma Infection

    Directory of Open Access Journals (Sweden)

    Cihan Cetin

    2016-12-01

    Full Text Available Toxoplasmosis is an infectious disease caused by a protozoa named Toxoplasma gondii. It is a very important disease because it is related to fetal anomalies and poor perinatal outcomes like abortus and stillbirth. It spreads via uncooked meat and contaminated food. Timely and appropriate treatment and management of this infection prenatally reduces the risk of serious neurological sequelae. Therefore it is crucial that clinician who takes care of pregnant women know this infection deeply. In this review we aimed to summarize the prenatal diagnosis, complications and treatment of toxoplasma infection. [Archives Medical Review Journal 2016; 25(4.000: 457-466

  14. Prosthetic Joint Infection

    Science.gov (United States)

    Tande, Aaron J.

    2014-01-01

    SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

  15. Imaging infection and inflammation

    International Nuclear Information System (INIS)

    Buscombe, John

    1997-01-01

    Full text. The use of nuclear medicine techniques to image infection has been with us for over 20 years, indeed this year sees the 20th anniversary of the publication of Matthew Thakur's paper of the use of In-111 oxime labelled leukocytes in imaging infection. Without doubt this technique has stood the test of time and has been used to save many lives in infected patients worldwide. As we approach the 21st century we are faced with new problems which will need new solutions. Infections themselves have changed their very nature, HIV a benign virus which only infected monkeys in central Africa in 1977 has now spread throughout the globe and unfortunately few societies have remained free of its ravages. In its wake tuberculosis continues to infect both the poor and weak but also has started to re-infect more affluent societies. In its wake tuberculosis continues to infect both both the poor and weak but also has started to re-infect more affluent societies. The use of immuno suppressive therapy in many patients with transplants or cancer has lead to new infections in a wider group of patients. The wide spread use of antibiotics has lead to the emergence of antibiotic resistant organisms. The old approach of widespread antibiotic treatment in patients with suspected infection is not acceptable. If possible organisms must be isolated. Normally imaging is required to localize infection and it is important to realize that a combination or anatomical imaging with CT, ultrasound or MRI and nuclear medicine is often the only way to determine the site of infection. Allied to this a new educated public has demanded that diagnostic tests be accurate and non-invasive, particularly in non-fatal inflammatory disease. All these challenges has lead us to a new frontier in nuclear medicine. In some ways we have had to rediscover the old. For example the use of Ga-67 citrate in imaging tuberculosis or infection in patients with Aids. The use of Tc-99 m HMPAO labelled leukocytes in

  16. Urinary Tract Infections (For Kids)

    Medline Plus

    Full Text Available ... Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & ... & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert ...

  17. Coxsackievirus Infections (For Parents)

    Science.gov (United States)

    ... hospital, including: viral meningitis , an infection of the meninges (membranes that surround the brain and spinal cord) ... and meningoencephalitis (an inflammation of the brain and meninges). In newborns, symptoms can develop within 2 weeks ...

  18. Pseudomonas aeruginosa Biofilm Infections

    DEFF Research Database (Denmark)

    Rybtke, Morten; Hultqvist, Louise Dahl; Givskov, Michael

    2015-01-01

    Studies of biopsies from infectious sites, explanted tissue and medical devises have provided evidence that biofilms are the underlying cause of a variety of tissue-associated and implant-associated recalcitrant human infections. With a need for novel anti-biofilm treatment strategies, research...... in biofilm infection microbiology, biofilm formation mechanisms and biofilm-associated antimicrobial tolerance has become an important area in microbiology. Substantial knowledge about biofilm formation mechanisms, biofilm-associated antimicrobial tolerance and immune evasion mechanisms has been obtained...... through work with biofilms grown in in vitro experimental setups, and the relevance of this information in the context of chronic infections is being investigated by the use of animal models of infection. Because our current in vitro experimental setups and animal models have limitations, new advanced...

  19. Sexually transmitted infections

    African Journals Online (AJOL)

    AJRH Managing Editor

    Sexually transmitted infections constitute economic burden for developing countries, exposure to causative agents is an occupational hazard ... In Nigeria, the deteriorating economic situation has led to ..... female sex workers from Mexico City.

  20. Urinary Tract Infection

    Science.gov (United States)

    ... discomfort Frequent, painful urination Blood in urine Urethra (urethritis) Burning with urination Discharge When to see a ... opening to the bladder. Infection of the urethra (urethritis). This type of UTI can occur when GI ...

  1. Pediatric Urinary Tract Infection

    Science.gov (United States)

    SBA National Resource Center: 800-621-3141 Pediatric Urinary Tract Infections and Catheterization in Children with Neurogenic Bladder and Bowel Why is it important to begin urologic care in infancy and ...

  2. Immunity to parasitic infection

    National Research Council Canada - National Science Library

    Lamb, Tracey J

    2012-01-01

    ... may be manipulated to develop therapeutic interventions against parasitic infection. For easy reference, the most commonly studied parasites are examined in individual chapters written by investigators at the forefront of their field...

  3. Surgical site infections

    African Journals Online (AJOL)

    Decrease the inflammatory response Vasodilatation leads to better perfusion and ... Must NOT be allowed to come in contact with brain, meninges, eyes or .... project (SCIP): Evolution of National Quality Measure. Surgical. Infection 2008 ...

  4. Helicobacter pylori infection

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007715.htm Helicobacter pylori infection To use the sharing features on this page, please enable JavaScript. Helicobacter pylori ( H pylori ) is a type of bacteria that ...

  5. Staph infections - hospital

    Science.gov (United States)

    ... to treat ordinary staph germs. What are Risk Factors for Staph Infection? Many healthy people normally have ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  6. Asymptomatic HIV infection

    Science.gov (United States)

    ... of HIV/AIDS during which there are no symptoms of HIV infection. During this phase, the immune system in someone with HIV slowly weakens, but the person has no symptoms. How long this phase lasts depends on how ...

  7. INFECTIVE ENDOCARDITIS: MODERN COURSE

    Directory of Open Access Journals (Sweden)

    T. L. Vinogradova

    2014-07-01

    Full Text Available The paper presents the characteristic features of the modern course of infective endocarditis. Unresolved questions of classification of diseaseand drug therapy are discussed. Clearly defined indications for surgical treatment of endocarditis.

  8. SURGICAL SITE INFECTION: REVIEW

    Directory of Open Access Journals (Sweden)

    P. H. M. Bonai

    2016-07-01

    Full Text Available Nosocomial infection or nosocomial infection (NI is one of the factors that increase the cost of maintaining patients in the health system, even in processes that should safely occur, such as hospital patients and performing simple and routine surgical procedures surgical centers and clinics leading to complications resulting from these infections that prolong hospital stay and promote pain and suffering to the patient, resulting in the defense of the quality of services and influencing negatively the hospitals. Therefore, the aim of this study was to review the factors that result in surgical site infection, with the purpose of better understanding of the subject and the possibility of preventive actions to better treatment outcome of the patient.

  9. Ear Infections in Children

    Science.gov (United States)

    ... ear infections may get better without antibiotics. Using antibiotics cautiously and with good reason helps prevent the development of bacteria that become resistant to antibiotics. If your doctor prescribes an antibiotic, it’s important ...

  10. Viruses infecting reptiles.

    Science.gov (United States)

    Marschang, Rachel E

    2011-11-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch's postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  11. Surgical site infections

    African Journals Online (AJOL)

    Surgical site infections (SSIs) are a worldwide problem that has ... deep tissue is found on clinical examination, re-opening, histopathological or radiological investigation ..... Esposito S, Immune system and SSI, Journal of Chemotherapy, 2001.

  12. Chlamydial infections - male

    Science.gov (United States)

    ... Swelling and tenderness of the testicles Chlamydia and gonorrhea often occur together. The symptoms of chlamydia infection may be similar to symptoms of gonorrhea, but they continue even after treatment for gonorrhea ...

  13. Viruses Infecting Reptiles

    Directory of Open Access Journals (Sweden)

    Rachel E. Marschang

    2011-11-01

    Full Text Available A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  14. Small Intestinal Infections.

    Science.gov (United States)

    Munot, Khushboo; Kotler, Donald P

    2016-06-01

    Small intestinal infections are extremely common worldwide. They may be bacterial, viral, or parasitic in etiology. Most are foodborne or waterborne, with specific etiologies differing by region and with diverse pathophysiologies. Very young, very old, and immune-deficient individuals are the most vulnerable to morbidity or mortality from small intestinal infections. There have been significant advances in diagnostic sophistication with the development and early application of molecular diagnostic assays, though these tests have not become mainstream. The lack of rapid diagnoses combined with the self-limited nature of small intestinal infections has hampered the development of specific and effective treatments other than oral rehydration. Antibiotics are not indicated in the absence of an etiologic diagnosis, and not at all in the case of some infections.

  15. Prevent Infections During Chemotherapy

    Centers for Disease Control (CDC) Podcasts

    This podcast discusses the importance of preventing infections in cancer patients who are undergoing chemotherapy. Dr. Lisa Richardson, CDC oncologist, talks about a new Web site for cancer patients and their caregivers.

  16. Healthcare Associated Infections - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Healthcare-Associated Infections (HAI) measures - national data. These measures are developed by Centers for Disease Control and Prevention (CDC) and collected...

  17. Healthcare Associated Infections - Hospital

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Healthcare-Associated Infection (HAI) measures - provider data. These measures are developed by Centers for Disease Control and Prevention (CDC) and collected...

  18. Toxoplasmosis (Toxoplasma infection) Treatment

    Science.gov (United States)

    ... Form Controls Cancel Submit Search the CDC Parasites - Toxoplasmosis (Toxoplasma infection) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Toxoplasmosis General Information Toxoplasmosis FAQs Toxoplasmosis & Pregnancy FAQs Epidemiology & ...

  19. Gastrointestinal Infections and Diarrhea

    Science.gov (United States)

    ... parasite, Cryptosporidium , is a common culprit behind diarrhea epidemics in childcare centers and other public places. Cryptosporidium ... take prescription antibiotics to prevent the infection from spreading throughout the body. What Can I Do to ...

  20. [Transplantation-associated infections].

    Science.gov (United States)

    Würzner, R

    2004-01-01

    Transplantation-associated infections are caused by an infected transplanted organ or the endogenic or exogenic environment of the recipient in a state of induced immunodeficiency. The best therapy would be to reconstitute the immunodeficiency, but this is usually impossible as it endangers the transplanted organ. Thus, a specific, standardised anti-infectious therapy is needed even in the absence of clearly identified micro-organisms [bacteria (in two thirds gram-positive rods), parasites (in central Europe predominantly Toxoplasma), fungi (especially Candida spp. or Aspergillus spp.) or viruses (such as Parvovirus B19 and Cytomegalovirus)]. Origins of infection (e.g., hygiene), types of infection (e.g., reactivation), typical localisations, diagnostic tools (e.g., blood cultures, antigenic tests, PCR, CT, advantages and disadvantages of antibody assays) and possible therapies are briefly discussed. The take home messages are to avoid economy measures in microbial diagnostics and to use CMV-seronegative donors whenever possible.

  1. Healthcare Associated Infections - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Healthcare-Associated Infections (HAI) measures - state data. These measures are developed by Centers for Disease Control and Prevention (CDC) and collected...

  2. NOROVIRUS INFECTION (SYSTEMATIC REVIEW

    Directory of Open Access Journals (Sweden)

    N. I. Khokhlova

    2018-01-01

    Full Text Available The share of norovirus infection is 17–20% of all cases of acute gastroenteritis in the world. The dominant II genogroup of noroviruses is characterized by rapid variability. The new recombinant norovirus GII.P16-GII.2 caused a sharp increase in the incidence of gastroenteritis in Asian and European countries during the winter season 2016–2017. The epidemiological features of norovirus infection are long-term excretion of the pathogen from the body of patients and carriers of viruses, especially in persons with immunosuppression; the implementation of various transmission routes (food, water, contact, aerosol, high contagiosity, winter seasonality in the countries of the northern hemisphere. In recent years, two human systems for the cultivation of noroviruses in vitro have been created, a double tropism of noroviruses has been established for immune cells and epithelial cells of the intestine, and the life cycle of noroviruses has been studied. The microbiota and its members can be either protective or stimulating for norovirus infection. Lactobacillus may play a protective role against norovirus infection. The existence of chronic norovirus infection lasting from several months to several years is proved, especially in patients with immunodeficiency. Severe form of norovirus infection and deaths are more often recorded in young children, the elderly, patients with comorbidity and immunocompromised individuals. The clinical picture of norovirus gastroenteritis is similar in many respects to other viral gastroenteritis, which determines the need for laboratory verification of the diagnosis. The polymerase chain reaction method with reverse transcription is the most widely used in the world for diagnosing infection in patients and for detecting the virus in food and environmental objects. There are still no approved vaccines and antiviral drugs against this infection. Recommended therapeutic interventions include, along with rehydration with

  3. [Bacterial biofilms and infection].

    Science.gov (United States)

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  4. [Saccharomyces cerevisiae infections].

    Science.gov (United States)

    Souza Goebel, Cristine; de Mattos Oliveira, Flávio; Severo, Luiz Carlos

    2013-01-01

    Saccharomyces cerevisiae is an ubiquitous yeast widely used in industry and it is also a common colonizer of the human mucosae. However, the incidence of invasive infection by these fungi has significantly increased in the last decades. To evaluate the infection by S. cerevisiae in a hospital in southern Brazil during a period of 10 years (2000-2010). Review of medical records of patients infected by this fungus. In this period, 6 patients were found to be infected by S. cerevisiae. The age range of the patients was from 10 years to 84. Urine, blood, ascitic fluid, peritoneal dialysis fluid, and esophageal biopsy samples were analyzed. The predisposing factors were cancer, transplant, surgical procedures, renal failure, use of venous catheters, mechanical ventilation, hospitalization in Intensive Care Unit, diabetes mellitus, chemotherapy, corticosteroid use, and parenteral nutrition. Amphotericin B and fluconazole were the treatments of choice. Three of the patients died and the other 3 were discharged from hospital. We must take special precautions in emerging infections, especially when there are predisposing conditions such as immunosuppression or patients with serious illnesses. The rapid and specific diagnosis of S. cerevisiae infections is important for therapeutic decision. Furthermore, epidemiological and efficacy studies of antifungal agents are necessary for a better therapeutic approach. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  5. Immunotherapy of Cryptococcus infections.

    Science.gov (United States)

    Antachopoulos, C; Walsh, T J

    2012-02-01

    Despite appropriate antifungal treatment, the management of cryptococcal disease remains challenging, especially in immunocompromised patients, such as human immunodeficiency virus-infected individuals and solid organ transplant recipients. During the past two decades, our knowledge of host immune responses against Cryptococcus spp. has been greatly advanced, and the role of immunomodulation in augmenting the response to infection has been investigated. In particular, the role of 'protective' Th1 (tumour necrosis factor-α, interferon (IFN)-γ, interleukin (IL)-12, and IL-18) and Th17 (IL-23 and IL-17) and 'non-protective' Th2 (IL-4, IL-10, and IL-13) cytokines has been extensively studied in vitro and in animal models of cryptococcal infection. Immunomodulation with monoclonal antibodies against the capsular polysaccharide glucuronoxylomannan, glucosylceramides, melanin and β-glucan and, lately, with radioimmunotherapy has also yielded promising results in animal models. As a balance between sufficiently protective Th1 responses and excessive inflammation is important for optimal outcome, the effect of immunotherapy may range from beneficial to deleterious, depending on factors related to the host, the infecting organism, and the immunomodulatory regimen. Clinical evidence supporting immunomodulation in patients with cryptococcal infection remains too limited to allow firm recommendations. Limited human data suggest a role for IFN-γ. Identification of surrogate markers characterizing patients' immunological status could possibly suggest candidate patients for immunotherapy and the type of immunomodulation to be administered. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  6. [Nosocomial virus infections].

    Science.gov (United States)

    Eggers, H J

    1986-12-01

    Enveloped viruses, e.g. influenza- or varicella viruses may cause highly contagious airborne infections. Their spread is difficult to control, also in hospitals. In the case of influenza and varicella immune prophylaxis and chemotherapy/chemoprophylaxis are possible. This is of particular significance, since varicella and zoster are of increasing importance for immunocompromized patients. Diarrhea is caused to a large extent by viruses. Rotavirus infections play an important role in infancy, and are frequently acquired in the hospital. In a study on infectious gastroenteritis of infants in a hospital we were able to show that 30 percent of all rotavirus infections were of nosocomial origin. Admission of a rotavirus-excreting patient (or personnel) may start a long chain of rotavirus infections on pediatric wards. Even careful hygienic measures in the hospital can hardly prevent the spread of enterovirus infections. Such infections may be severe and lethal for newborns, as shown by us in a study on an outbreak of echovirus 11 disease on a maternity ward. We have recently obtained data on the "stickiness" of enteroviruses on human skin. This could explain essential features of the spread of enteroviruses in the population.

  7. Postoperative spine infections

    Directory of Open Access Journals (Sweden)

    Paolo Domenico Parchi

    2015-09-01

    Full Text Available Postoperative spinal wound infection is a potentially devastating complication after operative spinal procedures. Despite the utilization of perioperative prophylactic antibiotics in recent years and improvements in surgical technique and postoperative care, wound infection continues to compromise patients’ outcome after spinal surgery. In the modern era of pending health care reform with increasing financial constraints, the financial burden of post-operative spinal infections also deserves consideration. The aim of our work is to give to the reader an updated review of the latest achievements in prevention, risk factors, diagnosis, microbiology and treatment of post-operative spinal wound infections. A review of the scientific literature was carried out using electronic medical databases Pubmed, Google Scholar, Web of Science and Scopus for the years 1973-2012 to obtain access to all publications involving the incidence, risk factors, prevention, diagnosis, treatment of postoperative spinal wound infections. We initially identified 119 studies; of these 60 were selected. Despite all the measures intended to reduce the incidence of surgical site infections in spine surgery, these remain a common and potentially dangerous complication.

  8. Necrotizing soft tissue infections - a multicentre, prospective observational study (INFECT)

    NARCIS (Netherlands)

    Madsen, M.B.; Skrede, S.; Bruun, T.; Arnell, P.; Rosén, A.; Nekludov, M.; Karlsson, Y.; Bergey, F.; Saccenti, E.; Martins dos Santos, V.A.P.; Perner, A.; Norrby-Teglund, A.; Hyldegaard, O.

    2018-01-01

    Background: The INFECT project aims to advance our understanding of the pathophysiological mechanisms in necrotizing soft tissue infections (NSTIs). The INFECT observational study is part of the INFECT project with the aim of studying the clinical profile of patients with NSTIs and correlating

  9. Detection and Characterization of Infections and Infection Susceptibility

    Science.gov (United States)

    2018-03-27

    Immune Disorders; Chronic Granulomatous Disease; Genetic Immunological Deficiencies; Hyperimmunoglobulin-E Recurrent Infection Syndrome; Recurrent Infections; Unknown Immune Deficiency; GATA2 Deficiency (MonoMAC); Nontuberculous Mycobacterial Infections; Hyper IgE (Job s) Syndrome; Leukocyte Adhesion Deficiency; Susceptibility to Disseminated Infections; Primary Immune Deficiency Disease (PIDD)

  10. Current management of fungal infections.

    NARCIS (Netherlands)

    Meis, J.F.G.M.; Verweij, P.E.

    2001-01-01

    The management of superficial fungal infections differs significantly from the management of systemic fungal infections. Most superficial infections are treated with topical antifungal agents, the choice of agent being determined by the site and extent of the infection and by the causative organism,

  11. Urinary Tract Infections (For Teens)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Urinary Tract Infections KidsHealth / For Teens / Urinary Tract Infections What's ... especially girls — visit a doctor. What Is a Urinary Tract Infection? A bacterial urinary tract infection (UTI) is ...

  12. A viral transcriptional activator of Kaposi's sarcoma-associated herpesvirus (KSHV) induces apoptosis, which is blocked in KSHV-infected cells

    International Nuclear Information System (INIS)

    Nishimura, Ken; Ueda, Keiji; Sakakibara, Shuhei; Do, Eunju; Ohsaki, Eriko; Okuno, Toshiomi; Yamanishi, Koichi

    2003-01-01

    Replication and transcription activator (RTA), mostly encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 50, is expressed in the immediate-early phase of reactivation and plays a critical role in inducing the viral lytic cycle in KSHV-infected cells. We established cell clones from BJAB cells and replication-deficient BCBL-1 cells in which KSHV RTA expression was controlled by an inducible promoter of the tetracycline-based Tet-Off expression system. In RTA-inducible BJAB cells, tetracycline removal induced the synthesis of RTA, resulting in cell death. DNA fragmentation, structural changes in the cell membrane, and poly(ADP-ribose) polymerase (PARP) cleavage were observed in the RTA-induced BJAB cells, indicating that RTA expression induced caspase activation and cell death by apoptosis. However, expression of RTA in RTA-inducible BCBL-1 cells did not undergo apoptosis and cell death. These results suggested that KSHV RTA is an apoptosis inducer that is opposed by an antiapoptotic pathway in infected cells

  13. Infected nonunion of tibia

    Directory of Open Access Journals (Sweden)

    Milind Madhav Chaudhary

    2017-01-01

    Full Text Available Infected nonunions of tibia pose many challenges to the treating surgeon and the patient. Challenges include recalcitrant infection, complex deformities, sclerotic bone ends, large bone gaps, shortening, and joint stiffness. They are easy to diagnose and difficult to treat. The ASAMI classification helps decide treatment. The nonunion severity score proposed by Calori measures many parameters to give a prognosis. The infection severity score uses simple clinical signs to grade severity of infection. This determines number of surgeries and allows choice of hardware, either external or internal for definitive treatment. Co-morbid factors such as smoking, diabetes, nonsteroidal anti-inflammatory drug use, and hypovitaminosis D influence the choice and duration of treatment. Thorough debridement is the mainstay of treatment. Removal of all necrotic bone and soft tissue is needed. Care is exercised in shaping bone ends. Internal fixation can help achieve union if infection was mild. Severe infections need external fixation use in a second stage. Compression at nonunion site achieves union. It can be combined with a corticotomy lengthening at a distant site for equalization. Soft tissue deficit has to be covered by flaps, either local or microvascular. Bone gaps are best filled with the reliable technique of bone transport. Regenerate bone may be formed proximally, distally, or at both sites. Acute compression can fill bone gaps and may need a fibular resection. Gradual reduction of bone gap happens with bone transport, without need for fibulectomy. When bone ends dock, union may be achieved by vertical or horizontal compression. Biological stimulus from iliac crest bone grafts, bone marrow aspirate injections, and platelet concentrates hasten union. Bone graft substitutes add volume to graft and help fill defects. Addition of rh-BMP-7 may help in healing albeit at a much higher cost. Regeneration may need stimulation and augmentation. Induced

  14. Chlamydiaceae infections in pig

    Directory of Open Access Journals (Sweden)

    Schautteet Katelijn

    2011-02-01

    Full Text Available Abstract Chlamydiaceae are Gram-negative obligate intracellular bacteria. They are responsible for a broad range of diseases in animals and humans. In pigs, Chlamydia suis, Chlamydia abortus, Chlamydia pecorum and Chlamydia psittaci have been isolated. Chlamydiaceae infections in pigs are associated with different pathologies such as conjunctivitis, pneumonia, pericarditis, polyarthritis, polyserositis, pseudo-membranous or necrotizing enteritis, periparturient dysgalactiae syndrome, vaginal discharge, return to oestrus, abortion, mummification, delivery of weak piglets, increased perinatal and neonatal mortality and inferior semen quality, orchitis, epididymitis and urethritis in boars. However, Chlamydiaceae are still considered as non-important pathogens because reports of porcine chlamydiosis are rare. Furthermore, Chlamydiaceae infections are often unnoticed because tests for Chlamydiaceae are not routinely performed in all veterinary diagnostic laboratories and Chlamydiaceae are often found in association with other pathogens, which are sometimes more easily to detect. However, recent studies have demonstrated that Chlamydiaceae infections in breeding sows, boars and piglets occur more often than thought and are economically important. This paper presents an overview on: the taxonomy of Chlamydiaceae occurring in pigs, diagnostic considerations, epidemiology and pathology of infections with Chlamydiaceae in pigs, public health significance and finally on prevention and treatment of Chlamydiaceae infections in pigs.

  15. Dengue viral infections

    Directory of Open Access Journals (Sweden)

    Gurugama Padmalal

    2010-01-01

    Full Text Available Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host, different serotypes, and favorable conditions for vector breeding have led to the virulence and spread of the infections. The manifestations of dengue infections are protean from being asymptomatic to undifferentiated fever, severe dengue infections, and unusual complications. Early recognition and prompt initiation of appropriate supportive treatment are often delayed resulting in unnecessarily high morbidity and mortality. Attempts are underway for the development of a vaccine for preventing the burden of this neglected disease. This review outlines the epidemiology, clinical features, pathophysiologic mechanisms, management, and control of dengue infections.

  16. HPV Infections in Adolescents

    Directory of Open Access Journals (Sweden)

    Anna-Barbara Moscicki

    2007-01-01

    Full Text Available Adolescents who are sexually active have the highest rates of prevalent and incident HPV infection rates with over 50–80% having infections within 2–3 years of initiating intercourse. These high rates reflect sexual behavior and biologic vulnerability. Most infections are transient in nature and cause no cytologic abnormality. However, a small number of adolescents will not clear the infection. Persistence of HPV is strongly linked to the development of high-grade squamous intra-epithelial lesions (HSIL and invasive cancer. The HSIL detected, however, does not appear to progress rapidly to invasive cancer. Understanding the natural history of HPV in adolescents has shed light into optional treatment strategies which include watchful observation of atypical squamous cells of undetermined significance (ASCUS and low grade (LSIL. The association between age of first intercourse and invasive cancer cannot be ignored. Consequently, initiating screening at appropriate times in this vulnerable group is essential. In addition, with the advent of the HPV vaccine, vaccination prior to the onset of sexual activity is critical since most infections occur within a short time frame post initiation.

  17. Pediatric spinal infections

    Directory of Open Access Journals (Sweden)

    Raj Kumar

    2014-01-01

    Full Text Available The infections of the spinal axis in children are rare when compared with adults. They encompass a large spectrum of diseases ranging from relatively benign diskitis to spinal osteomyleitis and to the rapidly progressive, rare, and potentially devastating spinal epidural, subdural, and intramedullary spinal cord infections. We present a comprehensive review of the literature pertaining to these uncommon entities, in light of our experience from northern India. The most prevalent pediatric spinal infection in Indian scenario is tuberculosis, where an extradural involvement is more common than intradural. The craniovertebral junction is not an uncommon site of involvement in children of our milieu. The majority of pyogenic infections of pediatric spine are associated with congenital neuro-ectodermal defects such as congenital dermal sinus. The clinico-radiological findings of various spinal infections commonly overlap. Hence the endemicity of certain pathogens should be given due consideration, while considering the differential diagnosis. However, early suspicion, rapid diagnosis, and prompt treatment are the key factors in avoiding neurological morbidity and deformity in a growing child.

  18. Infective Causes of Epilepsy.

    Science.gov (United States)

    Bonello, M; Michael, B D; Solomon, T

    2015-06-01

    A wide range of infections of the central nervous system are responsible for both acute seizures and epilepsy. The pathogenesis and clinical semiology of the seizure disorders vary widely between the infective pathogens. The exact mechanisms underlying this are poorly understood, but appear, at least in part, to relate to the pathogen; the degree of cortical involvement; delays in treatment; and the host inflammatory response. The treatment of infective causes of seizures involves both symptomatic treatment with antiepileptic drugs and direct treatment of the underlying condition. In many cases, early treatment of the infection may affect the prognosis of the epilepsy syndrome. The greatest burden of acute and long-term infection-related seizures occurs in resource-poor settings, where both clinical and research facilities are often lacking to manage such patients adequately. Nevertheless, education programs may go a long way toward addressing the stigma, leading to improved diagnosis, management, and ultimately to better quality of life. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  19. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display...... a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because...... the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially...

  20. Pregnancy and HIV infection

    Directory of Open Access Journals (Sweden)

    Mete Sucu

    2016-12-01

    Full Text Available The management of Human Immunodeficiency Virus (HIV infection is progressing rapidly. In developed countries, the perinatal transmission rates have decreased from 20-30% to 1-2% with the use of antiretroviral therapy and cesarean section. Interventions for the prevention of prenatal transmission has made the prenatal care of pregnant patients with HIV infection more complex. Rapid development of standard care and continuing increase in the distribution of HIV infection has required clinicians taking care of pregnants to have current information. Therefore, in our review we aimed to summarize the prenatal course, treatment and preventive methods for perinatal transmission of HIV. [Archives Medical Review Journal 2016; 25(4.000: 522-535

  1. Apoptosis in Pneumovirus Infection

    Directory of Open Access Journals (Sweden)

    Reinout A. Bem

    2013-01-01

    Full Text Available Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages during pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.

  2. Genital infections mycoplasma

    Directory of Open Access Journals (Sweden)

    Urošević R.

    2014-01-01

    Full Text Available During the retrospective study, which was conducted in the period from 01.01. to 31.12.2012, we have examined 1035 samples of vaginal secretions, cervical swabs and urethral swab the UU and Mh. The main objective of the study was to determine the incidence of mycoplasma infections, the distribution by sex, age of patients, the clinical diagnosis for which it was conducted microbiological testing of patients and determine the sensitivity of the isolated pathogens to antibiotics. From a total of 1035 samples tested positive findings were in 331 patients, of which 316 (95.5% women and 15 (4.5% males. The difference was statistically significant. There were no statistically significant differences in average age among women (29 years and women (30. Infection with a UU was statistically significantly higher (70.1% compared to the MH (5.4% and a mixed infection (24.5%. The incidence of infections caused by UU in females was 70% and 80% in males. Males and females do not differ significantly according to the frequency of infections caused by UU. The highest incidence of female patients, was diagnosed with vulvovaginitis 34% Colpitis had 22%; Colpitis and cervicitis-17%, while only Cervicitis was diagnosed in 10% of patients. The difference in the incidence of clinical diagnosis was statistically significant. The difference in the incidence of clinical diagnosis was statistically significant. All pathogens isolated showed significantly greater osteljivost three or more antibiotics. The sensitivity of the three or more antibiotics is not significantly associated with the cause of the infection.

  3. Infections, inflammation and epilepsy

    Science.gov (United States)

    Vezzani, Annamaria; Fujinami, Robert S.; White, H. Steve; Preux, Pierre-Marie; Blümcke, Ingmar; Sander, Josemir W.; Löscher, Wolfgang

    2016-01-01

    Epilepsy is the tendency to have unprovoked epileptic seizures. Anything causing structural or functional derangement of brain physiology may lead to seizures, and different conditions may express themselves solely by recurrent seizures and thus be labelled “epilepsy.” Worldwide, epilepsy is the most common serious neurological condition. The range of risk factors for the development of epilepsy varies with age and geographic location. Congenital, developmental and genetic conditions are mostly associated with the development of epilepsy in childhood, adolescence and early adulthood. Head trauma, infections of the central nervous system (CNS) and tumours may occur at any age and may lead to the development of epilepsy. Infections of the CNS are a major risk factor for epilepsy. The reported risk of unprovoked seizures in population-based cohorts of survivors of CNS infections from developed countries is between 6.8 and 8.3 %, and is much higher in resource-poor countries. In this review, the various viral, bacterial, fungal and parasitic infectious diseases of the CNS which result in seizures and epilepsy are discussed. The pathogenesis of epilepsy due to brain infections, as well as the role of experimental models to study mechanisms of epileptogenesis induced by infectious agents, is reviewed. The sterile (non-infectious) inflammatory response that occurs following brain insults is also discussed, as well as its overlap with inflammation due to infections, and the potential role in epileptogenesis. Furthermore, autoimmune encephalitis as a cause of seizures is reviewed. Potential strategies to prevent epilepsy resulting from brain infections and non-infectious inflammation are also considered. PMID:26423537

  4. Dipylidium caninum infection.

    Science.gov (United States)

    Cabello, Raúl Romero; Ruiz, Aurora Candil; Feregrino, Raul Romero; Romero, Leticia Calderón; Feregrino, Rodrigo Romero; Zavala, Jorge Tay

    2011-11-15

    Dipylidium caninum is a cestode that requires from the participation of an arthropod in its life cycle. This parasitosis occurs in dogs and cats, and occasionally in human beings. Human cases of D caninum infection have been reported in Europe, Philippines, China, Japan, Latin America and the United States; mostly children, one third of them being infants under 6 months old. The diagnosis of this disease is done by the parasitological study of the feces, observing the characteristics of the gravid proglottids. The treatment is performed by administering broad-spectrum anthelmintics. The authors report a case of a rare infection in a Mexican child.

  5. Neglected Parasitic Infections: Toxocariasis

    Centers for Disease Control (CDC) Podcasts

    2012-01-05

    This podcast is an overview of the Clinician Outreach and Communication Activity (COCA) Call: Neglected Parasitic Infections in the United States. Neglected Parasitic Infections are a group of diseases that afflict vulnerable populations and are often not well studied or diagnosed. A subject matter expert from CDC's Division of Parasitic Diseases and Malaria describes the epidemiology, diagnosis, and treatment of toxocariasis.  Created: 1/5/2012 by Center for Global Health, Division of Parasitic Diseases and Malaria (DPDM); Emergency Risk Communication Branch (ERCB)/Joint Information Center (JIC), Office of Public Health Preparedness and Response (OPHPR).   Date Released: 1/9/2012.

  6. Role of bacteriophages in STEC infections: new implications for the design of prophylactic and treatment approaches [v2; ref status: indexed, http://f1000r.es/437

    Directory of Open Access Journals (Sweden)

    Jaime H. Amorim

    2014-08-01

    Full Text Available Shiga toxin (Stx is considered the main virulence factor in Shiga toxin-producing Escherichia coli (STEC infections. Previously we reported the expression of biologically active Stx by eukaryotic cells in vitro and in vivo following transfection with plasmids encoding Stx under control of the native bacterial promoter1,2. Since stx genes are present in the genome of lysogenic bacteriophages, here we evaluated the relevance of bacteriophages during STEC infection. We used the non-pathogenic E. coli C600 strain carrying a lysogenic 933W mutant bacteriophage in which the stx operon was replaced by a gene encoding the green fluorescent protein (GFP. Tracking GFP expression using an In Vivo Imaging System (IVIS, we detected fluorescence in liver, kidney, and intestine of mice infected with the recombinant E. coli strain after treatment with ciprofloxacin, which induces the lytic replication and release of bacteriophages. In addition, we showed that chitosan, a linear polysaccharide composed of d-glucosamine residues and with a number of commercial and biomedical uses, had strong anti-bacteriophage effects, as demonstrated at in vitro and in vivo conditions. These findings bring promising perspectives for the prevention and treatment of haemolytic uremic syndrome (HUS cases.

  7. Giardia Infection (Giardiasis)

    Science.gov (United States)

    ... one of the most common causes of waterborne disease in the United States. The parasites are found in backcountry streams and lakes but also in municipal water supplies, swimming pools, whirlpool spas and wells. Giardia infection can be transmitted through food and person-to-person contact. Giardia ...

  8. Investigating Shigella sonnei Infections

    Centers for Disease Control (CDC) Podcasts

    2011-11-17

    Dr. Nancy Strockbine, Chief of the Escherichia and Shigella Reference Unit at CDC, discusses Shigella sonnei infections.  Created: 11/17/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/21/2011.

  9. Vitamin C and Infections.

    Science.gov (United States)

    Hemilä, Harri

    2017-03-29

    In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

  10. Vitamin C and Infections

    Directory of Open Access Journals (Sweden)

    Harri Hemilä

    2017-03-01

    Full Text Available In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose–response, for the duration of common cold symptoms, with up to 6–8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3–4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

  11. Mycoplasma genitalium Infections

    Centers for Disease Control (CDC) Podcasts

    2018-02-08

    Dr. Lisa Manhart, a professor of Epidemiology and Global Health with the Center for AIDS and STD at the University of Washington, discusses Mycoplasma genitalium Infections.  Created: 2/8/2018 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/8/2018.

  12. Wound Infections PSA (:30)

    Centers for Disease Control (CDC) Podcasts

    2017-10-25

    This 30 second public service announcement is about how to avoid a wound infection after a disaster.  Created: 10/25/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 10/25/2017.

  13. Candida infective endocarditis

    NARCIS (Netherlands)

    Baddley, J. W.; Benjamin, D. K.; Patel, M.; Miró, J.; Athan, E.; Barsic, B.; Bouza, E.; Clara, L.; Elliott, T.; Kanafani, Z.; Klein, J.; Lerakis, S.; Levine, D.; Spelman, D.; Rubinstein, E.; Tornos, P.; Morris, A. J.; Pappas, P.; Fowler, V. G.; Chu, V. H.; Cabell, C.; DraGordon, David; Devi, Uma; Spelman, Denis; van der Meer, Jan T. M.; Kauffman, Carol; Bradley, Suzanne; Armstrong, William; Giannitsioti, Efthymia; Giamarellou, Helen; Lerakis, Stamatios; del Rio, Ana; Moreno, Asuncio; Mestres, Carlos A.; Pare, Carlos; Garcia de la Maria, Cristina; de Lazzario, Elisa; Marco, Francesc; Gatell, Jose M.; Miro, Jose M.; Almela, Manel; Azqueta, Manuel; Jimenez-Exposito, Maria Jesus; de Benito, Natividad; Perez, Noel; Almirante, Benito; Fernandez-Hidalgo, Nuria; de Vera, Pablo Rodriguez; Tornos, Pilar; Falco, Vicente

    2008-01-01

    Candida infective endocarditis (IE) is uncommon but often fatal. Most epidemiologic data are derived from small case series or case reports. This study was conducted to explore the epidemiology, treatment patterns, and outcomes of patients with Candida IE. We compared 33 Candida IE cases to 2,716

  14. Group B Strep Infection

    Science.gov (United States)

    ... IV) to kill the germs. If you take antibiotics while you’re in labor, the chances are very good that your baby won’t get this infection. What if my baby has group B strep? If your baby gets group B strep, he or she will be treated with IV antibiotics to kill the bacteria. Your baby will stay ...

  15. Healing stone ... by infection

    OpenAIRE

    Micallef, Roderick

    2014-01-01

    Roderick Micallef has a long family history within the construction industry. He coupled this passion with a fascination with science when reading for an undergraduate degree in Biology and Chemistry (University of Malta). http://www.um.edu.mt/think/healing-stone-by-infection/

  16. Biophysics of biofilm infection.

    Science.gov (United States)

    Stewart, Philip S

    2014-04-01

    This article examines a likely basis of the tenacity of biofilm infections that has received relatively little attention: the resistance of biofilms to mechanical clearance. One way that a biofilm infection persists is by withstanding the flow of fluid or other mechanical forces that work to wash or sweep microorganisms out of the body. The fundamental criterion for mechanical persistence is that the biofilm failure strength exceeds the external applied stress. Mechanical failure of the biofilm and release of planktonic microbial cells is also important in vivo because it can result in dissemination of infection. The fundamental criterion for detachment and dissemination is that the applied stress exceeds the biofilm failure strength. The apparent contradiction for a biofilm to both persist and disseminate is resolved by recognizing that biofilm material properties are inherently heterogeneous. There are also mechanical aspects to the ways that infectious biofilms evade leukocyte phagocytosis. The possibility of alternative therapies for treating biofilm infections that work by reducing biofilm cohesion could (1) allow prevailing hydrodynamic shear to remove biofilm, (2) increase the efficacy of designed interventions for removing biofilms, (3) enable phagocytic engulfment of softened biofilm aggregates, and (4) improve phagocyte mobility and access to biofilm. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. Preventing infections when visiting

    Science.gov (United States)

    ... need.) When you visit a patient in the hospital, keep your hands away from your face. Cough or sneeze into a tissue or into the crease of your elbow, not into the air. References Calfee DP. Prevention and control of health care-associated infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  18. Yeast Infection during Pregnancy

    Science.gov (United States)

    ... disrupt the pH balance of the vagina. Common yeast infection symptoms include vaginal itching and a white, thick discharge that looks ... and Prevention. http://www.cdc.gov/std/tg2015/candidiasis.htm. Accessed Aug. 27, ... Vagina, Cervix, Toxic Shock Syndrome, Endometritis, and Salpingitis. In: ...

  19. Psychogenic "HIV infection"

    NARCIS (Netherlands)

    Sno, H. N.; Storosum, J. G.; Wortel, C. H.

    1991-01-01

    The case of a man who falsely represented himself as being HIV positive is reported. In less than one year he was admitted twice with symptoms suggestive of HIV infection. The diagnoses malingering and factitious disorder were consecutively made. Early recognition of Factitious Disorder is essential

  20. Bacteremic infection in hemodialysis.

    Science.gov (United States)

    Nsouli, K A; Lazarus, M; Schoenbaum, S C; Gottlieb, M N; Lowrie, E G; Shocair, M

    1979-11-01

    This is a retrospective study of 133 episodes of bacteremic infection in 112 hemodialysis patients. The frequency of bacteremic infection was 9.5% in patients with chronic renal failure and 10.9% in patients with acute renal failure. In patients with acute renal failure, pneumonia and intra-abdominal abscess were the most frequent sources of septicemia. Sepsis was usually due to Gram-negative organisms and mortality was high. In patients with chronic renal failure, infection of the shunt or fistula was the most common cause, was frequently due to Staphylococcus organism, and had a more favorable survival rate. Gram-negative septicemia from a nonaccess source in patients with chronic renal failure was associated with a higher mortality. Bacterial endocarditis and septic pulmonary emboli occurred in 3.6% of septic episodes and 0.35% of patients at risk and had very low mortality. A low threshold for obtaining blood cultures and early antibiotic treatment are believed to be important in the treatment of bacteremic infections in patients undergoing long-term hemodialysis.