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  1. Prostaglandin E2 Reduces the Release and Infectivity of New Cell-Free Virions and Cell-To-Cell HIV-1 Transfer

    PubMed Central

    Serramía, María Jesús; Martínez-Bonet, Marta; Muñoz-Fernández, María Ángeles

    2014-01-01

    Background The course of human immunodeficiency virus type-1 (HIV-1) infection is influenced by a complex interplay between viral and host factors. HIV infection stimulates several proinflammatory genes, such as cyclooxigense-2 (COX-2), which leads to an increase in prostaglandin (PG) levels in the plasma of HIV-1-infected patients. These genes play an indeterminate role in HIV replication and pathogenesis. The effect of prostaglandin E2 (PGE2) on HIV infection is quite controversial and even contradictory, so we sought to determine the role of PGE2 and the signal transduction pathways involved in HIV infection to elucidate possible new targets for antiretrovirals. Results Our results suggest that PGE2 post-infection treatment acts in the late stages of the viral cycle to reduce HIV replication. Interestingly, viral protein synthesis was not affected, but a loss of progeny virus production was observed. No modulation of CD4 CXCR4 and CCR5 receptor expression, cell proliferation, or activation after PGE2 treatment was detected. Moreover, PGE2 induced an increase in intracellular cAMP (cyclic AMP) levels through the EP2/EP4 receptors. PGE2 effects were mimicked by dbcAMP and by a specific Epac (exchange protein directly activated by cyclic AMP) agonist, 8-Cpt-cAMP. Treatment with PGE2 increased Rap1 activity, decreased RhoA activity and subsequently reduced the polymerization of actin by approximately 30% compared with untreated cells. In connection with this finding, polarized viral assembly platforms enriched in Gag were disrupted, altering HIV cell-to-cell transfer and the infectivity of new virions. Conclusions Our results demonstrate that PGE2, through Epac and Rap activation, alters the transport of newly synthesized HIV-1 components to the assembly site, reducing the release and infectivity of new cell-free virions and cell-to-cell HIV-1 transfer. PMID:24586238

  2. HCV infective virions can be carried by human platelets.

    PubMed

    Pugliese, A; Gennero, L; Cutufia, M; Enrietto, M; Morra, E; Pescarmona, P; Ponzetto, A

    2004-01-01

    It has been previously demonstrated that platelets (PLTs) can bind and transport HIV-1 infectious virions. Hepatitis C virus (HCV)-HIV-1 co-infection occurs frequently among users of illicit intravenous drugs, thereby increasing the severity of HIV disease and the evolution towards chronic active hepatitis and hepatocellular carcinoma of HCV-related hepatitis. In the present study we investigated whether or not PLTs can carry HCV, and studied the binding mechanisms. Purified PLTs, obtained from healthy donors, HCV negative and HIV negative, were adsorbed with HCV-containing serum and then employed to infect a THP-1 monocytoid cell line. Replication of HCV was observed as shown by positivity for the E2 antigen within THP-1 cells, by indirect immunofluorescence; moreover, HCV-RNA was detected in supernatants of THP-1 cells at day 7 post-incubation with HCV-adsorbed PLTs. The binding of HCV to PLTs seems to involve fibronectin (FN), as already shown in the case of HIV-1. Indeed, treatment with RGD (Gly-Arg-Gly-Asp-Ser), the key oligopeptide of FN binding, inhibits the ability of HCV to be carried by PLTs in infective forms; the same phenomenon occurs with Mabs to FN. Moreover the infection of THP-1 cells seems to increase FN surface expression, as demonstrated by immunofluorescence tests.

  3. Blocking of integrins inhibits HIV-1 infection of human cervical mucosa immune cells with free and complement-opsonized virions

    PubMed Central

    Tjomsland, Veronica; Ellegård, Rada; Kjölhede, Preben; Wodlin, Ninni Borendal; Hinkula, Jorma; Lifson, Jeffrey D; Larsson, Marie

    2013-01-01

    The initial interaction between HIV-1 and the host occurs at the mucosa during sexual intercourse. In cervical mucosa, HIV-1 exists both as free and opsonized virions and this might influence initial infection. We used cervical explants to study HIV-1 transmission, the effects of opsonization on infectivity, and how infection can be prevented. Complement opsonization enhanced HIV-1 infection of dendritic cells (DCs) compared with that by free HIV-1, but this increased infection was not observed with CD4+ T cells. Blockage of the α4-, β7-, and β1-integrins significantly inhibited HIV-1 infection of both DCs and CD4+ T cells. We found a greater impairment of HIV-1 infection in DCs for complement-opsonized virions compared with that of free virions when αM/β2- and α4-integrins were blocked. Blocking the C-type lectin receptor macrophage mannose receptor (MMR) inhibited infection of emigrating DCs but had no effect on CD4+ T-cell infection. We show that blocking of integrins decreases the HIV-1 infection of both mucosal DCs and CD4+ T cells emigrating from the cervical tissues. These findings may provide the basis of novel microbicidal strategies that may help limit or prevent initial infection of the cervical mucosa, thereby reducing or averting systemic HIV-1 infection. PMID:23686382

  4. Apolipoprotein E on Hepatitis C Virion Facilitates Infection through Interaction with Low Density Lipoprotein Receptor

    PubMed Central

    Owen, David M.; Huang, Hua; Ye, Jin; Gale, Michael

    2009-01-01

    Hepatitis C virus (HCV) infection is a major cause of liver disease. HCV associates with host apolipoproteins and enters hepatocytes through complex processes involving some combination of CD81, claudin-I, occludin, and scavenger receptor BI. Here we show that infectious HCV resembles very low density lipoprotein (VLDL) and that entry involves co-receptor function of the low density lipoprotein receptor (LDL-R). Blocking experiments demonstrate that β-VLDL itself or anti-apolipoprotein E (apoE) antibody can block HCV entry. Knockdown of the LDL-R by treatment with 25-hydroxycholesterol or siRNA ablated ligand uptake and reduced HCV infection of cells, whereas infection was rescued upon cell ectopic LDL-R expression. Analyses of gradient-fractionated HCV demonstrate that apoE is associated with HCV virions exhibiting peak infectivity and dependence upon the LDL-R for cell entry. Our results define the LDL-R as a cooperative HCV co-receptor that supports viral entry and infectivity through interaction with apoE ligand present in an infectious HCV/lipoprotein complex comprising the virion. Disruption of HCV/LDL-R interactions by altering lipoprotein metabolism may therefore represent a focus for future therapy. PMID:19751943

  5. A rev1-vpu polymorphism unique to HIV-1 subtype A and C strains impairs envelope glycoprotein expression from rev-vpu-env cassettes and reduces virion infectivity in pseudotyping assays

    SciTech Connect

    Kraus, Matthias H.; Parrish, Nicholas F.; Shaw, Katharina S.; Decker, Julie M.; Keele, Brandon F.; Salazar-Gonzalez, Jesus F.; Grayson, Truman; McPherson, David T.; Ping, Li-Hua; Anderson, Jeffrey A.; Swanstrom, Ronald; Williamson, Carolyn; Shaw, George M.; Hahn, Beatrice H.

    2010-02-20

    Functional studies of HIV-1 envelope glycoproteins (Envs) commonly include the generation of pseudoviruses, which are produced by co-transfection of rev-vpu-env cassettes with an env-deficient provirus. Here, we describe six Env constructs from transmitted/founder HIV-1 that were defective in the pseudotyping assay, although two produced infectious virions when expressed from their cognate proviruses. All of these constructs exhibited an unusual gene arrangement in which the first exon of rev (rev1) and vpu were in the same reading frame without an intervening stop codon. Disruption of the rev1-vpu fusion gene by frameshift mutation, stop codon, or abrogation of the rev initiation codon restored pseudovirion infectivity. Introduction of the fusion gene into wildtype Env cassettes severely compromised their function. The defect was not due to altered env and rev transcription or a dominant negative effect of the expressed fusion protein, but seemed to be caused by inefficient translation at the env initiation codon. Although the rev1-vpu polymorphism affects Env expression only in vitro, it can cause problems in studies requiring Env complementation, such as analyses of co-receptor usage and neutralization properties, since 3% of subtype A, 20% of subtype C and 5% of CRF01{sub A}/E viruses encode the fusion gene. A solution is to eliminate the rev initiation codon when amplifying rev-vpu-env cassettes since this increases Env expression irrespective of the presence of the polymorphism.

  6. Human immunodeficiency virus type 1 protease inhibitors irreversibly block infectivity of purified virions from chronically infected cells.

    PubMed

    Lambert, D M; Petteway, S R; McDanal, C E; Hart, T K; Leary, J J; Dreyer, G B; Meek, T D; Bugelski, P J; Bolognesi, D P; Metcalf, B W

    1992-05-01

    Synthetic peptide analog inhibitors of human immunodeficiency virus type 1 (HIV-1) protease were used to study the effects of inhibition of polyprotein processing on the assembly, structure, and infectivity of virions released from a T-cell line chronically infected with HIV-1. Inhibition of proteolytic processing of both Pr55gag and Pr160gag-pol was observed in purified virions from infected T cells after treatment. Protease inhibition was evident by the accumulation of precursors and processing intermediates of Pr55gag and by corresponding decreases in mature protein products. Electron microscopy revealed that the majority of the virion particles released from inhibitor-treated cells after a 24-h treatment had an immature or aberrant capsid morphology. This morphological change correlated with the inhibition of polyprotein processing and a loss of infectivity. The infectivity of virion particles purified from these chronically infected cell cultures was assessed following treatment with the inhibitor for 1 to 3 days. Virions purified from cultures treated with inhibitor for 1 or 2 days demonstrated a 95- to 100-fold reduction in virus titers, and treatment for 3 days resulted in complete loss of detectable infectivity. The fact that virions from treated cultures were unable to establish infection over the 7- to 10-day incubation period in the titration experiments strongly suggests that particles produced by inhibitor-treated cells were unable to reactivate to an infectious form when they were purified away from exogenous protease inhibitor. Thus, a block of HIV-1 protease processing of viral polyproteins by specific inhibitors results in a potent antiviral effect characterized by the production of noninfectious virions with altered protein structures and immature morphologies.

  7. The Tripartite Virions of the Brome Mosaic Virus Have Distinct Physical Properties That Affect the Timing of the Infection Process

    PubMed Central

    Vaughan, Robert; Tragesser, Brady; Ni, Peng; Ma, Xiang; Dragnea, Bogdan

    2014-01-01

    ABSTRACT The three subsets of virions that comprise the Brome mosaic virus (BMV) were previously thought to be indistinguishable. This work tested the hypothesis that distinct capsid-RNA interactions in the BMV virions allow different rates of viral RNA release. Several results support distinct interactions between the capsid and the BMV genomic RNAs. First, the deletion of the first eight residues of the BMV coat protein (CP) resulted in the RNA1-containing particles having altered morphologies, while those containing RNA2 were unaffected. Second, subsets of the BMV particles separated by density gradients into a pool enriched for RNA1 (B1) and for RNA2 and RNA3/4 (B2.3/4) were found to have different physiochemical properties. Compared to the B2.3/4 particles, the B1 particles were more sensitive to protease digestion and had greater resistivity to nanoindentation by atomic force microscopy and increased susceptibility to nuclease digestion. Mapping studies showed that portions of the arginine-rich N-terminal tail of the CP could interact with RNA1. Mutational analysis in the putative RNA1-contacting residues severely reduced encapsidation of BMV RNA1 without affecting the encapsidation of RNA2. Finally, during infection of plants, the more easily released RNA1 accumulated to higher levels early in the infection. IMPORTANCE Viruses with genomes packaged in distinct virions could theoretically release the genomes at different times to regulate the timing of gene expression. Using an RNA virus composed of three particles, we demonstrated that the RNA in one of the virions is released more easily than the other two in vitro. The differential RNA release is due to distinct interactions between the viral capsid protein and the RNAs. The ease of RNA release is also correlated with the more rapid accumulation of that RNA in infected plants. Our study identified a novel role for capsid-RNA interactions in the regulation of a viral infection. PMID:24672042

  8. Quantitative Correlation between Infectivity and Gp120 Density on HIV-1 Virions Revealed by Optical Trapping Virometry.

    PubMed

    DeSantis, Michael C; Kim, Jin H; Song, Hanna; Klasse, Per Johan; Cheng, Wei

    2016-06-17

    The envelope glycoprotein (Env) gp120/gp41 is required for HIV-1 infection of host cells. Although in general it has been perceived that more Env gives rise to higher infectivity, the precise quantitative dependence of HIV-1 virion infectivity on Env density has remained unknown. Here we have developed a method to examine this dependence. This method involves 1) production of a set of single-cycle HIV-1 virions with varied density of Env on their surface, 2) site-specific labeling of Env-specific antibody Fab with a fluorophore at high efficiency, and 3) optical trapping virometry to measure the number of gp120 molecules on individual HIV-1 virions. The resulting gp120 density per virion is then correlated with the infectivity of the virions measured in cell culture. In the presence of DEAE-dextran, the polycation known to enhance HIV-1 infectivity in cell culture, virion infectivity follows gp120 density as a sigmoidal dependence and reaches an apparent plateau. This quantitative dependence can be described by a Hill equation, with a Hill coefficient of 2.4 ± 0.6. In contrast, in the absence of DEAE-dextran, virion infectivity increases monotonically with gp120 density and no saturation is observed under the experimental conditions. These results provide the first quantitative evidence that Env trimers cooperate on the virion surface to mediate productive infection by HIV-1. Moreover, as a result of the low number of Env trimers on individual virions, the number of additional Env trimers per virion that is required for the optimal infectivity will depend on the inclusion of facilitating agents during infection. PMID:27129237

  9. During Infection, Theiler's Virions Are Cleaved by Caspases and Disassembled into Pentamers

    PubMed Central

    Arslan, Sevim Yildiz; Son, Kyung-No

    2016-01-01

    ABSTRACT Infected macrophages in spinal cords of mice persistently infected with Theiler's murine encephalomyelitis virus (TMEV) undergo apoptosis, resulting in restricted virus yields, as do infected macrophages in culture. Apoptosis of murine macrophages in culture occurs via the intrinsic pathway later in infection (>10 h postinfection [p.i.]) after maximal virus titers (150 to 200 PFU/cell) have been reached, with loss of most infectious virus (<5 PFU/cell) by 20 to 24 h p.i. Here, we show that BeAn virus RNA replication, translation, polyprotein processing into final protein products, and assembly of protomers and pentamers in infected M1-D macrophages did not differ from those processes in TMEV-infected BHK-21 cells, which undergo necroptosis. However, the initial difference from BHK-21 cell infection was seen at 10 to 12 h p.i., where virions from the 160S peak in sucrose gradients had incompletely processed VP0 (compared to that in infected BHK-21 cells). Thereafter, there was a gradual loss of the 160S virion peak in sucrose gradients, with replacement by a 216S peak that was observed to contain pentamers among lipid debris in negatively stained grids by electron microscopy. After infection or incubation of purified virions with activated caspase-3 in vitro, 13- and 17-kDa capsid peptide fragments were observed and were predicted by algorithms to contain cleavage sites within proteins by cysteine-dependent aspartate-directed proteases. These findings suggest that caspase cleavage of sites in exposed capsid loops of assembled virions occurs contemporaneously with the onset and progression of apoptosis later in the infection. IMPORTANCE Theiler's murine encephalomyelitis virus (TMEV) infection in mice results in establishment of virus persistence in the central nervous system and chronic inflammatory demyelinating disease, providing an experimental animal model for multiple sclerosis. Virus persistence takes place primarily in macrophages recruited into the

  10. Cooperation between the Hepatitis C Virus p7 and NS5B Proteins Enhances Virion Infectivity

    PubMed Central

    Aligeti, Mounavya; Roder, Allison

    2015-01-01

    ABSTRACT The molecular mechanisms that govern hepatitis C virus (HCV) assembly, release, and infectivity are still not yet fully understood. In the present study, we sequenced a genotype 2A strain of HCV (JFH-1) that had been cell culture adapted in Huh-7.5 cells to produce nearly 100-fold-higher viral titers than the parental strain. Sequence analysis identified nine mutations in the genome, present within both the structural and nonstructural genes. The infectious clone of this virus containing all nine culture-adapted mutations had 10-fold-higher levels of RNA replication and RNA release into the supernatant but had nearly 1,000-fold-higher viral titers, resulting in an increased specific infectivity compared to wild-type JFH-1. Two mutations, identified in the p7 polypeptide and NS5B RNA-dependent RNA polymerase, were sufficient to increase the specific infectivity of JFH-1. We found that the culture-adapted mutation in p7 promoted an increase in the size of cellular lipid droplets following transfection of viral RNA. In addition, we found that the culture-adaptive mutations in p7 and NS5B acted synergistically to enhance the specific viral infectivity of JFH-1 by decreasing the level of sphingomyelin in the virion. Overall, these results reveal a genetic interaction between p7 and NS5B that contributes to virion specific infectivity. Furthermore, our results demonstrate a novel role for the RNA-dependent RNA polymerase NS5B in HCV assembly. IMPORTANCE Hepatitis C virus assembly and release depend on viral interactions with host lipid metabolic pathways. Here, we demonstrate that the viral p7 and NS5B proteins cooperate to promote virion infectivity by decreasing sphingomyelin content in the virion. Our data uncover a new role for the viral RNA-dependent RNA polymerase NS5B and p7 proteins in contributing to virion morphogenesis. Overall, these findings are significant because they reveal a genetic interaction between p7 and NS5B, as well as an interaction with

  11. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection.

    PubMed

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-07-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca(2+) influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4(+) T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis.

  12. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection

    PubMed Central

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-01-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca2+ influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4+ T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis. PMID:27383627

  13. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection.

    PubMed

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-07-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca(2+) influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4(+) T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis. PMID:27383627

  14. The phosphorylation of HIV-1 Gag by atypical protein kinase C facilitates viral infectivity by promoting Vpr incorporation into virions

    PubMed Central

    2014-01-01

    Background Human immunodeficiency virus type 1 (HIV-1) Gag is the main structural protein that mediates the assembly and release of virus-like particles (VLPs) from an infected cell membrane. The Gag C-terminal p6 domain contains short sequence motifs that facilitate virus release from the plasma membrane and mediate incorporation of the viral Vpr protein. Gag p6 has also been found to be phosphorylated during HIV-1 infection and this event may affect virus replication. However, the kinase that directs the phosphorylation of Gag p6 toward virus replication remains to be identified. In our present study, we identified this kinase using a proteomic approach and further delineate its role in HIV-1 replication. Results A proteomic approach was designed to systematically identify human protein kinases that potently interact with HIV-1 Gag and successfully identified 22 candidates. Among this panel, atypical protein kinase C (aPKC) was found to phosphorylate HIV-1 Gag p6. Subsequent LC-MS/MS and immunoblotting analysis with a phospho-specific antibody confirmed both in vitro and in vivo that aPKC phosphorylates HIV-1 Gag at Ser487. Computer-assisted structural modeling and a subsequent cell-based assay revealed that this phosphorylation event is necessary for the interaction between Gag and Vpr and results in the incorporation of Vpr into virions. Moreover, the inhibition of aPKC activity reduced the Vpr levels in virions and impaired HIV-1 infectivity of human primary macrophages. Conclusion Our current results indicate for the first time that HIV-1 Gag phosphorylation on Ser487 is mediated by aPKC and that this kinase may regulate the incorporation of Vpr into HIV-1 virions and thereby supports virus infectivity. Furthermore, aPKC inhibition efficiently suppresses HIV-1 infectivity in macrophages. aPKC may therefore be an intriguing therapeutic target for HIV-1 infection. PMID:24447338

  15. Human α-Defensins Inhibit BK Virus Infection by Aggregating Virions and Blocking Binding to Host Cells*

    PubMed Central

    Dugan, Aisling S.; Maginnis, Melissa S.; Jordan, Joslynn A.; Gasparovic, Megan L.; Manley, Kate; Page, Rebecca; Williams, Geoffrey; Porter, Edith; O'Hara, Bethany A.; Atwood, Walter J.

    2008-01-01

    BK virus (BKV) is a polyomavirus that establishes a lifelong persistence in most humans and is a major impediment to success of kidney grafts. The function of the innate immune system in BKV infection and pathology has not been investigated. Here we examine the role of antimicrobial defensins in BKV infection of Vero cells. Our data show that α-defensin human neutrophil protein 1 (HNP1) and human α-defensin 5 (HD5) inhibit BKV infection by targeting an early event in the viral lifecycle. HD5 treatment of BKV reduced viral attachment to cells, whereas cellular treatment with HD5 did not. Colocalization studies indicated that HD5 interacts directly with BKV. Ultrastructural analysis revealed HD5-induced aggregation of virions. HD5 also inhibited infection of cells by other related polyomaviruses. This is the first study to demonstrate polyomavirus sensitivity to defensins. We also show a novel mechanism whereby HD5 binds to BKV leading to aggregation of virion particles preventing normal virus binding to the cell surface and uptake into cells. PMID:18782756

  16. Cellular minichromosome maintenance complex component 5 (MCM5) is incorporated into HIV-1 virions and modulates viral replication in the newly infected cells

    PubMed Central

    Santos, Steven; Obukhov, Yuri; Nekhai, Sergei; Pushkarsky, Tatiana; Brichacek, Beda; Bukrinsky, Michael; Iordanskiy, Sergey

    2016-01-01

    The post-entry events of HIV-1 infection occur within reverse transcription complexes derived from the viral cores entering the target cell. HIV-1 cores contain host proteins incorporated from virus-producing cells. In this report, we show that MCM5, a subunit of the hexameric minichromosome maintenance (MCM) DNA helicase complex, associates with Gag polyprotein and is incorporated into HIV-1 virions. The progeny virions depleted of MCM5 demonstrated reduced reverse transcription in newly infected cells, but integration and subsequent replication steps were not affected. Interestingly, increased packaging of MCM5 into the virions also led to reduced reverse transcription, but here viral replication was impaired. Our data suggest that incorporation of physiological amounts of MCM5 promotes aberrant reverse transcription, leading to partial incapacitation of cDNA, whereas increased MCM5 abundance leads to reduced reverse transcription and infection. Therefore, MCM5 has the properties of an inhibitory factor that interferes with production of an integration-competent cDNA product. PMID:27414250

  17. Virions and intracellular nucleocapsids produced during mixed heterotypic influenza infection of MDCK cells

    SciTech Connect

    Sklyanskaya, E.I.; Varich, N.L.; Amvrosieva, T.V.; Kaverin, N.V.

    1985-02-01

    Phenotypically mixed virus yields, obtained by coinfection of MDCK cells with influenza A/WSN/33 and B/Lee/40 viruses, contained both A/WSN/33 and B/Lee/40 NP proteins, as revealed by polyacrylamide gel electrophoresis of the purified /sup 14/C-amino acids-labeled virus. Virions were lysed with 0.6 M KCl-Triton X-100 buffer, and nucleocapsids were immunoprecipitated with antibodies against NP protein of influenza A virus. Polyacrylamide gel electrophoresis of the immunoprecipitate revealed NP protein of A/WSN/33 but not of B/Lee/40 virus. However, in similar experiments with the lysates of doubly infected cells, the band of B/Lee/40 NP protein was revealed in the polyacrylamide gel electrophoresis patterns of the immunoprecipitates. In an attempt to analyze the RNA content of the immune complexes, the authors absorbed the lysates of doubly infected (/sup 3/H)uridine-labeled cells with protein A-containing Staphylococcus aureus covered with antibodies against the NP protein of influenza A virus. RNA extracted from the immune complexes contained genomic RNA segments of both A/WSN/33 and B/Lee/40 viruses. In control samples containing an artificial mixture of cell lysates separately infected with each virus, the analysis revealed homologous components (i.e., A/WSN/33 NP protein or RNA segments) in the immune complexes. The results suggest the presence of phenotypically mixed nucleocapsids in the cells doubly infected with influenza A and B viruses; in the course of the virion formation, the nucleocapsids lacking the heterologous NP protein are selected.

  18. Proteomic analysis of the herpes simplex virus 1 virion protein 16 transactivator protein in infected cells.

    PubMed

    Suk, Hyung; Knipe, David M

    2015-06-01

    The herpes simplex virus 1 virion protein 16 (VP16) tegument protein forms a transactivation complex with the cellular proteins host cell factor 1 (HCF-1) and octamer-binding transcription factor 1 (Oct-1) upon entry into the host cell. VP16 has also been shown to interact with a number of virion tegument proteins and viral glycoprotein H to promote viral assembly, but no comprehensive study of the VP16 proteome has been performed at early times postinfection. We therefore performed a proteomic analysis of VP16-interacting proteins at 3 h postinfection. We confirmed the interaction of VP16 with HCF-1 and a large number of cellular Mediator complex proteins, but most surprisingly, we found that the major viral protein associating with VP16 is the infected cell protein 4 (ICP4) immediate-early (IE) transactivator protein. These results raise the potential for a new function for VP16 in associating with the IE ICP4 and playing a role in transactivation of early and late gene expression, in addition to its well-documented function in transactivation of IE gene expression.

  19. Infection of a Single Cell Line with Distinct Strains of Human Cytomegalovirus Can Result in Large Variations in Virion Production and Facilitate Efficient Screening of Virus Protein Function

    PubMed Central

    Zavala, Anamaria G.; O'Dowd, John M.

    2015-01-01

    ABSTRACT Previously, we reported that the absence of the ataxia telangiectasia mutated (ATM) kinase, a critical DNA damage response (DDR) signaling component for double-strand breaks, caused no change in HCMV Towne virion production. Later, others reported decreased AD169 viral titers in the absence of ATM. To address this discrepancy, human foreskin fibroblasts (HFF) and three ATM− lines (GM02530, GM05823, and GM03395) were infected with both Towne and AD169. Two additional ATM− lines (GM02052 and GM03487) were infected with Towne. Remarkably, both previous studies' results were confirmed. However, the increased number of cell lines and infections with both lab-adapted strains confirmed that ATM was not necessary to produce wild-type-level titers in fibroblasts. Instead, interactions between individual virus strains and the cellular microenvironment of the individual ATM− line determined efficiency of virion production. Surprisingly, these two commonly used lab-adapted strains produced drastically different titers in one ATM− cell line, GM05823. The differences in titer suggested a rapid method for identifying genes involved in differential virion production. In silico comparison of the Towne and AD169 genomes determined a list of 28 probable candidates responsible for the difference. Using serial iterations of an experiment involving virion entry and input genome nuclear trafficking with a panel of related strains, we reduced this list to four (UL129, UL145, UL147, and UL148). As a proof of principle, reintroduction of UL148 largely rescued genome trafficking. Therefore, use of a battery of related strains offers an efficient method to narrow lists of candidate genes affecting various virus life cycle checkpoints. IMPORTANCE Human cytomegalovirus (HCMV) infection of multiple cell lines lacking ataxia telangiectasia mutated (ATM) protein produced wild-type levels of infectious virus. Interactions between virus strains and the microenvironment of individual

  20. Proteomic Analysis of the Herpes Simplex Virus 1 Virion Protein 16 Transactivator Protein in Infected Cells

    PubMed Central

    Oh, Hyung Suk; Knipe, David M.

    2015-01-01

    The herpes simplex virus 1 VP16 tegument protein forms a transactivation complex with the cellular proteins HCF-1 and Oct-1 upon entry into the host cell. VP16 has also been shown to interact with a number of virion tegument proteins and viral glycoprotein H to promote viral assembly, but no comprehensive study of the VP16 proteome has been performed at early times post-infection. We therefore performed a proteomic analysis of VP16-interacting proteins at 3 hours post-infection. We confirmed the interaction of VP16 with HCF-1 and a large number of cellular Mediator complex proteins, but most surprisingly, we found that the major viral protein associating with VP16 is the ICP4 immediate-early transactivator protein. These results raise the potential for a new function for VP16 in associating with the immediate-early ICP4 and playing a role in transactivation of early and late gene expression, in addition to its well-documented function in transactivation of immediate-early gene expression. PMID:25809282

  1. Early events in herpes simplex virus type 1 infection: photosensitivity of fluorescein isothiocyanate-treated virions

    SciTech Connect

    DeLuca, N.; Bzik, D.; Person, S.; Snipes, W.

    1981-02-01

    Herpes simplex virus type 1 is photosensitized by treatment with fluorescein isothiocyanate (FITC). The inactivation of FITC-treated virions upon subsequent exposure to light is inhibited by the presence of sodium azide, suggesting the involvement of singlet oxygen in the process. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed that treatment with FITC plus light induces crosslinks in viral envelope glycoproteins. Treatment of virions with high concentrations of FITC (50 ..mu..g/ml) plus light causes a reduction in the adsorption of the virus to monolayers of human embryonic lung cells. For lower concentrations of FITC (10 ..mu..g/ml) plus light, treated virions adsorb to the host cells, but remain sensitive to light until entry occurs. The loss of light sensitivity coincides with the development of resistance to antibodies. These results are most consistent with a mechanism of entry for herpes simplex virus involving fusion of the viral membrane with the plasma membrane of the host cell.

  2. Estimating the fraction of progeny virions that must incorporate APOBEC3G for suppression of productive HIV-1 infection

    SciTech Connect

    Thangavelu, Pulari U.; Gupta, Vipul; Dixit, Narendra M.

    2014-01-20

    The contest between the host factor APOBEC3G (A3G) and the HIV-1 protein Vif presents an attractive target of intervention. The extent to which the A3G–Vif interaction must be suppressed to tilt the balance in favor of A3G remains unknown. We employed stochastic simulations and mathematical modeling of the within-host dynamics and evolution of HIV-1 to estimate the fraction of progeny virions that must incorporate A3G to render productive infection unsustainable. Using three different approaches, we found consistently that a transition from sustained infection to suppression of productive infection occurred when the latter fraction exceeded ∼0.8. The transition was triggered by A3G-induced hypermutations that led to premature stop codons compromising viral production and was consistent with driving the basic reproductive number, R{sub 0}, below unity. The fraction identified may serve as a quantitative guideline for strategies targeting the A3G–Vif axis. - Highlights: • We perform simulations and mathematical modeling of the role of APOBEC3G in suppressing HIV-1 infection. • In three distinct ways, we estimate that when over 80% of progeny virions carry APOBEC3G, productive HIV-1 infection would be suppressed. • Our estimate of this critical fraction presents quantitative guidelines for strategies targeting the APOBEC3G–Vif axis.

  3. BST2/CD317 counteracts human coronavirus 229E productive infection by tethering virions at the cell surface

    SciTech Connect

    Wang, Shiu-Mei; Huang, Kuo-Jung; Wang, Chin-Tien

    2014-01-20

    Bone marrow stromal antigen 2 (BST2), an interferon-inducible antiviral factor, has been shown to block the release of various enveloped viruses from cells. It has also been identified as an innate immune system component. Most enveloped viruses subject to BST2 restriction bud at the plasma membrane. Here we report our findings that (a) the production of human coronavirus 229E (HCoV-229E) progeny viruses, whose budding occurs at the ER-Golgi intermediate compartment (ERGIC), markedly decreases in the presence of BST2; and (b) BST2 knockdown expression results in enhanced HCoV-229E virion production. Electron microscopy analyses indicate that HCoV-229E virions are tethered to cell surfaces or intracellular membranes by BST2. Our results suggest that BST2 exerts a broad blocking effect against enveloped virus release, regardless of whether budding occurs at the plasma membrane or intracellular compartments. - Highlights: • BST2 knockdown expression results in enhanced HCoV-229E egress. • HCoV-229E virions are tethered to cell surfaces or intracellular membranes by BST2. • HCoV-229E infection at high MOI can significantly downregulate HeLa BST2 and rescue HIV-1 egress.

  4. The virion N protein of infectious bronchitis virus is more phosphorylated than the N protein from infected cell lysates

    SciTech Connect

    Jayaram, Jyothi; Youn, Soonjeon; Collisson, Ellen W. . E-mail: ecollisson@cvm.tamu.edu

    2005-08-15

    Because phosphorylation of the infectious bronchitis virus (IBV) nucleocapsid protein (N) may regulate its multiple roles in viral replication, the dynamics of N phosphorylation were examined. {sup 32}P-orthophosphate labeling and Western blot analyses confirmed that N was the only viral protein that was phosphorylated. Pulse labeling with {sup 32}P-orthophosphate indicated that the IBV N protein was phosphorylated in the virion, as well as at all times during infection in either chicken embryo kidney cells or Vero cells. Pulse-chase analyses followed by immunoprecipitation of IBV N proteins using rabbit anti-IBV N polyclonal antibody demonstrated that the phosphate on the N protein was stable for at least 1 h. Simultaneous labeling with {sup 32}P-orthophosphate and {sup 3}H-leucine identified a 3.5-fold increase in the {sup 32}P:{sup 3}H counts per minute (cpm) ratio of N in the virion as compared to the {sup 32}P:{sup 3}H cpm ratio of N in the cell lysates from chicken embryo kidney cells, whereas in Vero cells the {sup 32}P:{sup 3}H cpm ratio of N from the virion was 10.5-fold greater than the {sup 32}P:{sup 3}H cpm ratio of N from the cell lysates. These studies are consistent with the phosphorylation of the IBV N playing a role in assembly or maturation of the viral particle.

  5. Murine Cytomegalovirus Virion-Associated Protein M45 Mediates Rapid NF-κB Activation after Infection

    PubMed Central

    Krause, Eva; de Graaf, Miranda; Fliss, Patricia M.; Dölken, Lars

    2014-01-01

    ABSTRACT Murine cytomegalovirus (MCMV) rapidly induces activation of nuclear factor κB (NF-κB) upon infection of host cells. After a transient phase of activation, the MCMV M45 protein blocks all canonical NF-κB-activating pathways by inducing the degradation of the gamma subunit of the inhibitor of κB kinase complex (IKKγ; commonly referred to as the NF-κB essential modulator [NEMO]). Here we show that the viral M45 protein also mediates rapid NF-κB activation immediately after infection. MCMV mutants lacking M45 or expressing C-terminally truncated M45 proteins induced neither NF-κB activation nor transcription of NF-κB-dependent genes within the first 3 h of infection. Rapid NF-κB activation was absent in MCMV-infected NEMO-deficient fibroblasts, indicating that activation occurs at or upstream of the IKK complex. NF-κB activation was strongly reduced in murine fibroblasts lacking receptor-interacting protein 1 (RIP1), a known M45-interacting protein, but was restored upon complementation with murine RIP1. However, the ability of M45 to interact with RIP1 and NEMO was not sufficient to induce NF-κB activation upon infection. In addition, incorporation of the M45 protein into virions was required. This was dependent on a C-terminal region of M45, which is not required for interaction with RIP1 and NEMO. We propose a model in which M45 delivered by viral particles activates NF-κB, presumably involving an interaction with RIP1 and NEMO. Later in infection, expression of M45 induces the degradation of NEMO and the shutdown of canonical NF-κB activation. IMPORTANCE Transcription factor NF-κB is an important regulator of innate and adaptive immunity. Its activation can be beneficial or detrimental for viral pathogens. Therefore, many viruses interfere with NF-κB signaling by stimulating or inhibiting the activation of this transcription factor. Cytomegaloviruses, opportunistic pathogens that cause lifelong infections in their hosts, activate NF

  6. Aberrant virion assembly and limited glycoprotein C production in varicella-zoster virus-infected neurons.

    PubMed

    Grose, Charles; Yu, Xiaoli; Cohrs, Randall J; Carpenter, John E; Bowlin, Jacqueline L; Gilden, Don

    2013-09-01

    Highly pure (>95%) terminally differentiated neurons derived from pluripotent stem cells appear healthy at 2 weeks after infection with varicella-zoster virus (VZV), and the cell culture medium contains no infectious virus. Analysis of the healthy-appearing neurons revealed VZV DNA, transcripts, and proteins corresponding to the VZV immediate early, early, and late kinetic phases of replication. Herein, we further characterized virus in these neuronal cells, focusing on (i) transcription and expression of late VZV glycoprotein C (gC) open reading frame 14 (ORF14) and (ii) ultrastructural features of virus particles in neurons. The analysis showed that gC was not expressed in most infected neurons and gC expression was markedly reduced in a minority of VZV-infected neurons. In contrast, expression of the early-late VZV gE glycoprotein (ORF68) was abundant. Transcript analysis also showed decreased gC transcription compared with gE. Examination of viral structure by high-resolution transmission electron microscopy revealed fewer viral particles than typically observed in cells productively infected with VZV. Furthermore, viral particles were more aberrant, in that most capsids in the nuclei lacked a dense core and most enveloped particles in the cytoplasm were light particles (envelopes without capsids). Together, these results suggest a considerable deficiency in late-phase replication and viral assembly during VZV infection of neurons in culture.

  7. The size and conformation of Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) DNA in infected cells and virions.

    PubMed Central

    Renne, R; Lagunoff, M; Zhong, W; Ganem, D

    1996-01-01

    The genome of a novel human herpesvirus has been detected in specimens of Kaposi's sarcoma (KS) and in several AIDS-related lymphoproliferative disorders. Here we examine the size and genomic conformation of the DNA of this virus (known as KS-associated herpesvirus or human herpesvirus 8) in latently and lytically infected cells and in virions. Pulsed-field gel electrophoresis of viral DNA shows that the viral genome is similar in size to those of other gammaherpesviruses (160 to 170 kb). As with Epstein-Barr virus, KS-associated herpesvirus DNA is stably maintained in latently infected B cells as episomal monomer circles and induction from latency is associated with the selective accumulation of linear genomic forms. PMID:8892944

  8. Differential segregation of nodaviral coat protein and RNA into progeny virions during mixed infection with FHV and NoV

    PubMed Central

    Gopal, Radhika; Venter, P. Arno; Schneemann, Anette

    2014-01-01

    Nodaviruses are icosahedral viruses with a bipartite, positive-sense RNA genome. The two RNAs are packaged into a single virion by a poorly understood mechanism. We chose two distantly related nodaviruses, Flock House virus and Nodamura virus, to explore formation of viral reassortants as a means to further understand genome recognition and encapsidation. In mixed infections, the viruses were incompatible at the level of RNA replication and their coat proteins segregated into separate populations of progeny particles. RNA packaging, on the other hand, was indiscriminate as all four viral RNAs were detectable in each progeny population. Consistent with the trans-encapsidation phenotype, fluorescence in situ hybridization of viral RNA revealed that the genomes of the two viruses co-localized throughout the cytoplasm. Our results imply that nodaviral RNAs lack rigorously defined packaging signals and that coencapsidation of the viral RNAs does not require a pair of cognate RNA1 and RNA2. PMID:24725955

  9. Estimating the fraction of progeny virions that must incorporate APOBEC3G for suppression of productive HIV-1 infection.

    PubMed

    Thangavelu, Pulari U; Gupta, Vipul; Dixit, Narendra M

    2014-01-20

    The contest between the host factor APOBEC3G (A3G) and the HIV-1 protein Vif presents an attractive target of intervention. The extent to which the A3G-Vif interaction must be suppressed to tilt the balance in favor of A3G remains unknown. We employed stochastic simulations and mathematical modeling of the within-host dynamics and evolution of HIV-1 to estimate the fraction of progeny virions that must incorporate A3G to render productive infection unsustainable. Using three different approaches, we found consistently that a transition from sustained infection to suppression of productive infection occurred when the latter fraction exceeded ~0.8. The transition was triggered by A3G-induced hypermutations that led to premature stop codons compromising viral production and was consistent with driving the basic reproductive number, R0, below unity. The fraction identified may serve as a quantitative guideline for strategies targeting the A3G-Vif axis.

  10. Comparison of effects of adjuvants on efficacy of virion envelope herpes simplex virus vaccine against labial infection of BALB/c mice.

    PubMed Central

    Thomson, T A; Hilfenhaus, J; Moser, H; Morahan, P S

    1983-01-01

    A subunit virion envelope vaccine of herpes simplex virus type 1 was evaluated for its ability to protect labially infected mice from development of the primary herpetic lesion, encephalitic death, and latent virus infection in the trigeminal ganglion. Several adjuvants, including aluminum hydroxide and polyriboinosinic acid-polyribocytidylic acid complexed with poly-L-lysine and carboxymethyl cellulose were investigated for their ability to enhance protection of the subunit vaccine and were compared in effectiveness with complete Freund adjuvant. The subunit vaccine was demonstrated to be immunogenic, as shown by development of antibody detectable by an enzyme-linked immunosorbent assay. The humoral immune response was correlated with protection from herpetic encephalitis and, at a lower degree, with prevention of the appearance of primary herpetic lesions and acceleration of lesion resolution. The efficacy of the vaccine was most apparent in protecting mice from encephalitic death. To reduce or prevent the development of latent infection was most difficult, but was achieved with some vaccine regimens. Repeated administrations of vaccine with adjuvant were required for this protection. The most effective adjuvant was complete Freund adjuvant, but several synthetic adjuvants were effective, particularly aluminum hydroxide and the polyriboinosinic-polyribocytidylic acid-poly-L-lysine-carboxymethyl cellulose immunoadjuvant. PMID:6307874

  11. Cholesterol Flux Is Required for Endosomal Progression of African Swine Fever Virions during the Initial Establishment of Infection

    PubMed Central

    Cuesta-Geijo, Miguel Ángel; Chiappi, Michele; Galindo, Inmaculada; Barrado-Gil, Lucía; Muñoz-Moreno, Raquel; Carrascosa, José L.

    2015-01-01

    ABSTRACT African swine fever virus (ASFV) is a major threat for porcine production that has been slowly spreading in Eastern Europe since its first appearance in the Caucasus in 2007. ASFV enters the cell by endocytosis and gains access to the cytosol to start replication from late endosomes and multivesicular bodies. Cholesterol associated with low-density lipoproteins entering the cell by endocytosis also follows a trafficking pathway similar to that of ASFV. Here we show that cholesterol plays an essential role in the establishment of infection as the virus traffics through the endocytic pathway. In contrast to the case for other DNA viruses, such as vaccinia virus or adenovirus 5, cholesterol efflux from endosomes is required for ASFV release/entry to the cytosol. Accumulation of cholesterol in endosomes impairs fusion, resulting in retention of virions inside endosomes. ASFV also remodels intracellular cholesterol by increasing its cellular uptake and redistributes free cholesterol to viral replication sites. Our analysis reveals that ASFV manipulates cholesterol dynamics to ensure an appropriate lipid flux to establish productive infection. IMPORTANCE Since its appearance in the Caucasus in 2007, African swine fever (ASF) has been spreading westwards to neighboring European countries, threatening porcine production. Due to the lack of an effective vaccine, ASF control relies on early diagnosis and widespread culling of infected animals. We investigated early stages of ASFV infection to identify potential cellular targets for therapeutic intervention against ASF. The virus enters the cell by endocytosis, and soon thereafter, viral decapsidation occurs in the acid pH of late endosomes. We found that ASFV infection requires and reorganizes the cellular lipid cholesterol. ASFV requires cholesterol to exit the endosome to gain access to the cytoplasm to establish productive replication. Our results indicate that there is a differential requirement for cholesterol

  12. A new avian hepadnavirus infecting snow geese (Anser caerulescens) produces a significant fraction of virions containing single-stranded DNA.

    PubMed

    Chang, S F; Netter, H J; Bruns, M; Schneider, R; Frölich, K; Will, H

    1999-09-15

    We describe the identification and functional analysis of an evolutionary distinct new avian hepadnavirus. Infection of snow geese (Anser caerulescens) with a duck hepatitis B virus (DHBV)-related virus, designated SGHBV, was demonstrated by detection of envelope proteins in sera with anti-DHBV preS and S antibodies. Comparative sequence analysis of the PCR-amplified SGHBV genomes revealed unique SGHBV sequence features compared with other avian hepadnaviruses. Unlike DHBV, SGHBV shows an open reading frame in an analogous position to orthohepadnavirus X genes. Four of five cloned genomes were competent in replication, gene expression, and virus particle secretion in chicken hepatoma cells. Primary duck hepatocytes were permissive for infection with SGHBV, suggesting a similar or identical host range. SGHBV was found to secrete a significant fraction of virion-like particles containing single-stranded viral DNA. This was observed both in cell culture medium of SGHBV DNA-transfected LMH cells and in viremic sera of several birds, suggesting that it is a stable trait of SGHBV. Taken together, SGHBV has several unique features that expand the knowledge of the functional and evolutionary diversity of hepadnaviruses and offers new experimental opportunities for studies on the life cycle of hepadnaviruses. PMID:10489339

  13. Interaction of poxvirus intracellular mature virion proteins with the TPR domain of kinesin light chain in live infected cells revealed by two-photon-induced fluorescence resonance energy transfer fluorescence lifetime imaging microscopy.

    PubMed

    Jeshtadi, Ananya; Burgos, Pierre; Stubbs, Christopher D; Parker, Anthony W; King, Linda A; Skinner, Michael A; Botchway, Stanley W

    2010-12-01

    Using two-photon-induced fluorescence lifetime imaging microscopy, we corroborate an interaction (previously demonstrated by yeast two-hybrid domain analysis) of full-length vaccinia virus (VACV; an orthopoxvirus) A36 protein with the cellular microtubule motor protein kinesin. Quenching of enhanced green fluorescent protein (EGFP), fused to the C terminus of VACV A36, by monomeric red fluorescent protein (mDsRed), fused to the tetratricopeptide repeat (TPR) domain of kinesin, was observed in live chicken embryo fibroblasts infected with either modified vaccinia virus Ankara (MVA) or wild-type fowlpox virus (FWPV; an avipoxvirus), and the excited-state fluorescence lifetime of EGFP was reduced from 2.5 ± 0.1 ns to 2.1 ± 0.1 ns due to resonance energy transfer to mDsRed. FWPV does not encode an equivalent of intracellular enveloped virion surface protein A36, yet it is likely that this virus too must interact with kinesin to facilitate intracellular virion transport. To investigate possible interactions between innate FWPV proteins and kinesin, recombinant FWPVs expressing EGFP fused to the N termini of FWPV structural proteins Fpv140, Fpv168, Fpv191, and Fpv198 (equivalent to VACV H3, A4, p4c, and A34, respectively) were generated. EGFP fusions of intracellular mature virion (IMV) surface protein Fpv140 and type II membrane protein Fpv198 were quenched by mDsRed-TPR in recombinant FWPV-infected cells, indicating that these virion proteins are found within 10 nm of mDsRed-TPR. In contrast, and as expected, EGFP fusions of the IMV core protein Fpv168 did not show any quenching. Interestingly, the p4c-like protein Fpv191, which demonstrates late association with preassembled IMV, also did not show any quenching.

  14. Epstein-Barr virus infection of CR2-transfected epithelial cells reveals the presence of MHC class II on the virion.

    PubMed

    Knox, P G; Young, L S

    1995-10-20

    Epithelial cell lines transfected with the Epstein-Barr virus (EBV) receptor CR2 are susceptible to infection by EBV. Following infection with certain EBV strains we found that these cells became positive for MHC class II. The class II was confirmed as being of viral and not target cell origin by immunostaining with HLA-specific monoclonal antibodies. Electron microscopic immunogold staining confirmed the presence of MHC class II on the surface of the virion. While some MHC class I was also found on the EB virion, other cell surface molecules were absent. Dual color immunofluorescence and confocal microscopy analysis demonstrated colocalization of class II with EBV-encoded structural proteins (MA and VCA) in infected epithelial cells. However, preincubation of EBV with antibodies against either MHC class I or MHC class II failed to affect either EBV binding or EBV infection. The presence of MHC on the surface of the EB virion may be a consequence of the intracellular pathways through which productive virus exits from the cell and may influence the target cell tropism of EBV. PMID:7483258

  15. Efficacy of a virion envelope herpes simplex virus vaccine against experimental skin infections in hairless mice.

    PubMed

    Klein, R J; Buimovici-Klein, E; Moser, H; Moucha, R; Hilfenhaus, J

    1981-01-01

    Hairless mice were immunized with herpes simplex virus type 1 (HSV-1) envelope antigen (EAG), EAG in association with polyriboinosinic . polyribocytidylic acid-poly-L-lysine complexed with carboxymethylcellulose (PICLC), and inactivated purified HSV-1 (VAG). After 2 weeks the mice were challenged by a percutaneous HSV-1 infection in the orofacial (OF) or lumbosacral (LS) skin area. Following immunization a consistent cell-mediated immune response was observed in all immunized mice, although the humoral immune response was very low, or not detectable. After challenge, a marked secondary humoral and cell-mediated immune response developed in all immunized mice, and the animals were protected against the development of skin lesions and the fatal outcome of infection. However, the establishment of latent infections in the sensory ganglia was not prevented by the immunization procedure.

  16. Effective Binding of a Phosphatidylserine-Targeting Antibody to Ebola Virus Infected Cells and Purified Virions

    PubMed Central

    Dowall, S. D.; Graham, V. A.; Corbin-Lickfett, K.; Empig, C.; Schlunegger, K.; Bruce, C. B.; Easterbrook, L.; Hewson, R.

    2015-01-01

    Ebola virus is responsible for causing severe hemorrhagic fevers, with case fatality rates of up to 90%. Currently, no antiviral or vaccine is licensed against Ebola virus. A phosphatidylserine-targeting antibody (PGN401, bavituximab) has previously been shown to have broad-spectrum antiviral activity. Here, we demonstrate that PGN401 specifically binds to Ebola virus and recognizes infected cells. Our study provides the first evidence of phosphatidylserine-targeting antibody reactivity against Ebola virus. PMID:25815346

  17. A conserved carboxy-terminal domain in the major tegument structural protein VP22 facilitates virion packaging of a chimeric protein during productive herpes simplex virus 1 infection

    SciTech Connect

    Schlegel, Elisabeth F.M.; Blaho, John A.

    2009-05-10

    Recombinant virus HSV-1(RF177) was previously generated to examine tegument protein VP22 function by inserting the GFP gene into the gene encoding VP22. During a detailed analysis of this virus, we discovered that RF177 produces a novel fusion protein between the last 15 amino acids of VP22 and GFP, termed GCT-VP22. Thus, the VP22 carboxy-terminal specific antibody 22-3 and two anti-GFP antibodies reacted with an approximately 28 kDa protein from RF177-infected Vero cells. GCT-VP22 was detected at 1 and 3 hpi. Examination of purified virions indicated that GCT-VP22 was incorporated into RF177 virus particles. These observations imply that at least a portion of the information required for virion targeting is located in this domain of VP22. Indirect immunofluorescence analyses showed that GCT-VP22 also localized to areas of marginalized chromatin during RF177 infection. These results indicate that the last fifteen amino acids of VP22 participate in virion targeting during HSV-1 infection.

  18. Zinc binding to the HCCH motif of HIV-1 virion infectivity factor induces a conformational change that mediates protein-protein interactions.

    PubMed

    Paul, Indrani; Cui, Jian; Maynard, Ernest L

    2006-12-01

    Virion infectivity factor (Vif) is an accessory protein encoded by HIV-1 and is critical for viral infection of the host CD4(+) T cell population. Vif induces ubiquitination and subsequent degradation of Apo3G, a cytosolic cytidine deaminase that otherwise targets the retroviral genome. Interaction of Vif with the cellular Cullin5-based E3 ubiquitin ligase requires a conserved BC box and upstream residues that are part of the conserved H-(Xaa)(5)-C-(Xaa)(17-18)-C-(Xaa)(3-5)-H (HCCH) motif. The HCCH motif is involved in stabilizing the Vif-Cullin 5 interaction, but the exact role of the conserved His and Cys residues remains elusive. In this report, we find that full-length HIV-1 Vif, as well as a HCCH peptide, is capable of binding to zinc with high specificity. Zinc binding induces a conformational change that leads to the formation of large protein aggregates. EDTA reversed aggregation and regenerated the apoprotein conformation. Cysteine modification studies with the HCCH peptide suggest that C114 is critical for stabilizing the fold of the apopeptide, and that C133 is located in a solvent-exposed region with no definite secondary structure. Selective alkylation of C133 reduced metal-binding specificity of the HCCH peptide, allowing cobalt to bind with rates comparable to that with zinc. This study demonstrates that the HCCH motif of HIV-1 Vif is a unique metal-binding domain capable of mediating protein-protein interactions in the presence of zinc and adds to a growing list of examples in which metal ion binding induces protein misfolding and/or aggregation.

  19. Reducing haemodialysis access infection rates.

    PubMed

    Dorman, Amanda; Dainton, Marissa

    Infections are the second most common cause of vascular access loss in the long-term haemodialysis patient, and recent years have seen an increase in healthcare-associated infections (HCAIs) associated with vascular access (Suhail, 2009). There have been a number of drivers including publication guidelines (Department of Health, 2006; 2007) and local protocols providing evidence-based recommendations that, when implemented, can reduce the risk of these infections. In England, the selection of bloodstream infections caused by methicillin resistant staphylococcus aureus (MRSA) as a significant clinical outcome has led to a vast amount of work in this area. Root cause analysis of individual infections (by the clinical teams when these occur) in many specialities identified areas where practice could be improved, including practice relating to vascular access within the renal setting. Manufacturers have also supported this work by focusing on developing products that are designed to reduce the likelihood of infections occurring. One product identified and used within the NHS is Chloraprep. PMID:21646994

  20. Resistance of a vaccinia virus A34R deletion mutant to spontaneous rupture of the outer membrane of progeny virions on the surface of infected cells

    SciTech Connect

    Husain, Matloob; Weisberg, Andrea S.; Moss, Bernard

    2007-09-30

    The extracellular form of vaccinia virus is referred to as an enveloped virion (EV) because it contains an additional lipoprotein membrane surrounding the infectious mature virion (MV) that must be discarded prior to cell fusion and entry. Most EVs adhere to the surface of the parent cell and mediate spread of the infection to adjacent cells. Here we show that some attached EVs have ruptured envelopes. Rupture was detected by fluorescence microscopy of unfixed and unpermeabilized cells using antibodies to the F13 and L1 proteins, which line the inner side of the EV membrane and the outer side of the MV membrane, respectively. The presence of ruptured EV membranes was confirmed by immunogold transmission electron microscopy. EVs with broken membranes were present on several cell lines examined including one deficient in glycosaminoglycans, which are thought to play a role in breakage of the EV membrane prior to fusion of the MV. No correlation was found between EVs with ruptured membranes and actin tail formation. Studies with several mutant viruses indicated that EV membranes lacking the A34 protein were unbroken. This result was consistent with other properties of A34R deletion mutants including resistance of the EV membrane to polyanions, small plaque formation and low infectivity that can be increased by disruption of the EV membrane by freezing and thawing.

  1. HIV-1 Infection Leads to Increased Transcription of Human Endogenous Retrovirus HERV-K (HML-2) Proviruses In Vivo but Not to Increased Virion Production

    PubMed Central

    Bhardwaj, Neeru; Maldarelli, Frank; Mellors, John

    2014-01-01

    ABSTRACT Recent studies suggest that human endogenous retrovirus group K (HERV-K) provirus expression plays a role in the pathogenesis of HIV-1 infection. In particular, RNA from the HML-2 subgroup of HERV-K proviruses has been reported to be highly expressed at the cellular level and detectable in the plasma of HIV-1-infected patients, suggestive of virion production and, perhaps, replication. In this study, we developed an HML-2-specific quantitative-PCR assay that detects 51 of the 89 known HML-2 proviruses in the human genome. Plasma and peripheral blood mononuclear cells (PBMCs) from HIV-negative controls and HIV-1-infected patients were collected for analysis of HML-2 RNA expression. Contrary to previous reports, we did not detect high levels of HML-2 RNA in the plasma of HIV-1-infected patients, but we did observe a significant increase of HML-2 RNA in total PBMCs compared to HIV-negative controls. The level of HML-2 expression in PBMCs does not appear to be related to patient use of antiretrovirals or to HIV-1 plasma RNA, cellular RNA, or cellular DNA levels. To investigate the source of HML-2 RNA expression, patient PBMCs were sorted into CD3+ CD4+, CD3+ CD8+, CD3− CD14+, and CD3− CD20+ cell subsets and then analyzed for HML-2 RNA levels. No single cell subset was enriched for HML-2 RNA expression in HIV-1-infected patients, but there appears to be substantial variability in the level of HML-2 expression depending on the cell type. IMPORTANCE Here, we report that human endogenous retrovirus group K (HERV-K) (HML-2) proviruses are expressed at significantly higher levels in peripheral blood mononuclear cells (PBMCs) from patients with HIV-1 infection than in those from uninfected individuals. However, contrary to previous reports, this expression did not lead to detectable virions in the plasma of these patients. In addition, we found that HML-2 proviruses were expressed in multiple blood cell types from HIV-1-infected individuals, and the magnitude of

  2. Virion-associated HIV-1 Vpr: variable amount in virus particles derived from cells upon virus infection or proviral DNA transfection.

    PubMed

    Singh, S P; Tungaturthi, P; Cartas, M; Tomkowicz, B; Rizvi, T A; Khan, S A; Kalyanaraman, V S; Srinivasan, A

    2001-04-25

    Human immunodeficiency virus type-1 (HIV-1) Vpr is a virion-associated protein implicated to have a role in AIDS pathogenesis. In regard to the amount of Vpr incorporated into virus particles, the published data vary widely. To address this, we quantitated Vpr in virus particles derived from diverse sources that are used to evaluate the biological effect of Vpr. Virus particles from infected cells showed only a small amount of Vpr. Interestingly, virus particles from cells cotransfected with HIV-1 proviral DNA lacking Vpr coding sequences (NLDeltaVpr) and a Vpr expression plasmid showed a drastic increase (29.4-fold) in the incorporation of Vpr. Furthermore, cotransfection involving NLDeltaVpr and different concentrations of Vpr expression plasmid resulted in virus particles containing Vpr in proportion to the Vpr expression plasmid used. The differences in virus particles with respect to Vpr as revealed by these studies should be taken into account in assessing the effect of Vpr.

  3. Cleavage of the HPV16 Minor Capsid Protein L2 during Virion Morphogenesis Ablates the Requirement for Cellular Furin during De Novo Infection

    PubMed Central

    Cruz, Linda; Biryukov, Jennifer; Conway, Michael J.; Meyers, Craig

    2015-01-01

    Infections by high-risk human papillomaviruses (HPV) are the causative agents for the development of cervical cancer. As with other non-enveloped viruses, HPVs are taken up by the cell through endocytosis following primary attachment to the host cell. Through studies using recombinant pseudovirus particles (PsV), many host cellular proteins have been implicated in the process. The proprotein convertase furin has been demonstrated to cleave the minor capsid protein, L2, post-attachment to host cells and is required for infectious entry by HPV16 PsV. In contrast, using biochemical inhibition by a furin inhibitor and furin-negative cells, we show that tissue-derived HPV16 native virus (NV) initiates infection independent of cellular furin. We show that HPV16 L2 is cleaved during virion morphogenesis in differentiated tissue. In addition, HPV45 is also not dependent on cellular furin, but two other alpha papillomaviruses, HPV18 and HPV31, are dependent on the activity of cellular furin for infection. PMID:26569287

  4. The virion host shutoff RNase plays a key role in blocking the activation of protein kinase R in cells infected with herpes simplex virus 1.

    PubMed

    Sciortino, Maria Teresa; Parisi, Tiziana; Siracusano, Gabriel; Mastino, Antonio; Taddeo, Brunella; Roizman, Bernard

    2013-03-01

    Earlier studies have shown that active MEK blocks the activation of protein kinase R (PKR), a component of antiviral innate immune responses. In this report we show that the herpes simplex virus 1 virion host shutoff (VHS) RNase protein and MEK (mitogen-activated protein kinase kinase) act cooperatively in blocking the activation of PKR. This conclusion is based on the following. (i) In contrast to viral gene expression in the parental cell line or a cell line expressing a constitutively active MEK, the replication of a VHS mutant is particularly impaired in cells expressing dominant negative MEK. In this cell line PKR is activated by phosphorylation, and the accumulation of several viral proteins is delayed. (ii) In transfected cells, wild-type VHS blocked the activation of PKR, whereas PKR was activated in cells transfected with a mutant VHS or with plasmids encoding the VHS RNase and VP16 and VP22, the two viral proteins that neutralize the RNase activity of VHS. The results suggest that early in infection the VHS RNase degrades RNAs that activate PKR. Coupled with published data, the results suggest that inhibition of activation of PKR or its effect on viral replication is staged early in infection by VHS, postsynthesis of VP16 and VP22 by the γ(1)34.5 protein, and very late in infection by the U(S)11 protein.

  5. 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

    SciTech Connect

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

    2011-01-05

    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.

  6. Elimination of contaminating cap genes in AAV vector virions reduces immune responses and improves transgene expression in a canine gene therapy model.

    PubMed

    Wang, Z; Halbert, C L; Lee, D; Butts, T; Tapscott, S J; Storb, R; Miller, A D

    2014-04-01

    Animal and human gene therapy studies utilizing AAV vectors have shown that immune responses to AAV capsid proteins can severely limit transgene expression. The main source of capsid antigen is that associated with the AAV vectors, which can be reduced by stringent vector purification. A second source of AAV capsid proteins is that expressed from cap genes aberrantly packaged into AAV virions during vector production. This antigen source can be eliminated by the use of a cap gene that is too large to be incorporated into an AAV capsid, such as a cap gene containing a large intron (captron gene). Here, we investigated the effects of elimination of cap gene transfer and of vector purification by CsCl gradient centrifugation on AAV vector immunogenicity and expression following intramuscular injection in dogs. We found that both approaches reduced vector immunogenicity and that combining the two produced the lowest immune responses and highest transgene expression. This combined approach enabled the use of a relatively mild immunosuppressive regimen to promote robust micro-dystrophin gene expression in Duchenne muscular dystrophy-affected dogs. Our study shows the importance of minimizing AAV cap gene impurities and indicates that this improvement in AAV vector production may benefit human applications.

  7. Reducing urinary tract infections in catheterised patients.

    PubMed

    Howe, Pam; Adams, John

    2015-01-20

    Urinary tract infections in catheterised patients continue to present a challenge in reducing healthcare-associated infection. In this article, an infection prevention and control team in one NHS trust reports on using audit results to focus attention on measures to reduce bacterial infections. Educational initiatives have an important role in reducing infection, but there is no single solution to the problem. Practice can be improved using a multi-targeted approach, peer review and clinical audit to allow for shared learning and experiences. These, along with informal education in the clinical area and more formal classroom lectures, can ultimately lead to improved patient outcomes.

  8. The vaccinia virus I1 protein is essential for the assembly of mature virions.

    PubMed Central

    Klemperer, N; Ward, J; Evans, E; Traktman, P

    1997-01-01

    The product of the vaccinia virus I1 gene was characterized biochemically and genetically. This 35-kDa protein is conserved in diverse members of the poxvirus family but shows no homology to nonviral proteins. We show that recombinant I1 binds to both single-stranded and double-stranded DNA in a sequence-nonspecific manner in an electrophoretic mobility shift assay. The protein is expressed at late times during infection, and approximately 700 copies are encapsidated within the virion core. To determine the role of the I1 protein during the viral life cycle, a inducible viral recombinant in which the I1 gene was placed under the regulation of the Escherichia coli lac operator/repressor was constructed. In the absence of isopropyl-beta-D-thiogalactopyranoside, plaque formation was abolished and yields of infectious, intracellular virus were dramatically reduced. Although all phases of gene expression and DNA replication proceeded normally during nonpermissive infections, no mature virions were produced. Electron microscopic analysis confirmed the absence of mature virion assembly but revealed that apparently normal immature virions accumulated. Thus, I1 is an encapsidated DNA-binding protein required for the latest stages of vaccinia virion morphogenesis. PMID:9371587

  9. Antibodies of symptomatic human immunodeficiency virus type 1-infected individuals are directed to the V3 domain of noninfectious and not of infectious virions present in autologous serum.

    PubMed Central

    Schreiber, M; Petersen, H; Wachsmuth, C; Müller, H; Hufert, F T; Schmitz, H

    1994-01-01

    The present study was designed to determine the antibody specificity for the human immunodeficiency virus type 1 (HIV-1) V3 domains of infectious and noninfectious virions present in the serum of AIDS patients. To accomplish this, HIV-1 was isolated in the presence of autologous antibodies from the serum samples of six AIDS patients in HIV-1-negative donor peripheral blood mononuclear cells by short-term cultivation. The isolated virus, defined as the infectious cell-free virus (iCFV), was characterized by sequence analysis of the proviral DNA coding for the third hypervariable (V3) region of the external glycoprotein gp120. This was carried out by amplifying and cloning the V3 region. In all six cases studied, 20 randomly selected V3 clones derived from the proviral DNA of the iCFV, 20 clones from patient cell-free virus, and 20 clones from cell-integrated virus were sequenced to study the distribution and frequency of the intrapatient virus population. The number of major virus variants in the six patients ranged from three to nine. The various V3 sequences found in the AIDS patients showed the typical amino acid pattern of the syncytium-inducing and non-syncytium-inducing viral phenotypes characteristic for the late stage of infection. However, only one patient-specific iCFV variant was detected within the 20 V3 clones analyzed per virus isolation. For the six patients a total of 34 V3-loop variants, either iCFV or non-iCFV, was observed. All 34 V3-loop sequences were expressed as glutathione-S-transferase fusion proteins (V3-GST). The autologous antibody response to the V3-GST fusion proteins was studied by Western immunoblot analysis. A strong antibody response to almost all non-iCFV V3-GST proteins was found in the sera of the six patients. In contrast, the autologous antibody response to the six iCFV V3 loops was undetectable (in four patients) or very faint (in two patients) compared with that to the non-iCFV V3 loops. Five of the six iCFV loops showed

  10. Vaccinia virus A19 protein participates in the transformation of spherical immature particles to barrel-shaped infectious virions.

    PubMed

    Satheshkumar, P S; Weisberg, Andrea S; Moss, Bernard

    2013-10-01

    The A19L open reading frame of vaccinia virus encodes a 9-kDa protein that is conserved in all sequenced chordopoxviruses, yet until now it has not been specifically characterized in any species. We appended an epitope tag after the start codon of the A19L open reading frame without compromising infectivity. The protein was synthesized after viral DNA replication and was phosphorylated independently of the vaccinia virus F10 kinase. The A19 protein was present in purified virions and was largely resistant to nonionic detergent extraction, suggesting a location within the core. A conditional lethal mutant virus was constructed by placing the A19 open reading frame under the control of the Escherichia coli lac repressor system. A19 synthesis and infectious virus formation were dependent on inducer. In the absence of inducer, virion morphogenesis was interrupted, and spherical dense particles that had greatly reduced amounts of the D13 scaffold accumulated in place of barrel-shaped mature virions. The infectivity of purified A19-deficient particles was more than 2 log units less than that of A19-containing virions. Nevertheless, the A19-deficient particles contained DNA, and except for the absence of A19 and decreased core protein processing, they appeared to have a similar protein composition as A19-containing virions. Thus, the A19 protein participates in the maturation of immature vaccinia virus virions to infectious particles.

  11. An Anti-Influenza Virus Antibody Inhibits Viral Infection by Reducing Nucleus Entry of Influenza Nucleoprotein.

    PubMed

    Yoon, Aerin; Yi, Kye Sook; Chang, So Young; Kim, Sung Hwan; Song, Manki; Choi, Jung Ah; Bourgeois, Melissa; Hossain, M Jaber; Chen, Li-Mei; Donis, Ruben O; Kim, Hyori; Lee, Yujean; Hwang, Do Been; Min, Ji-Young; Chang, Shin Jae; Chung, Junho

    2015-01-01

    To date, four main mechanisms mediating inhibition of influenza infection by anti-hemagglutinin antibodies have been reported. Anti-globular-head-domain antibodies block either influenza virus receptor binding to the host cell or progeny virion release from the host cell. Anti-stem region antibodies hinder the membrane fusion process or induce antibody-dependent cytotoxicity to infected cells. In this study we identified a human monoclonal IgG1 antibody (CT302), which does not inhibit both the receptor binding and the membrane fusion process but efficiently reduced the nucleus entry of viral nucleoprotein suggesting a novel inhibition mechanism of viral infection by antibody. This antibody binds to the subtype-H3 hemagglutinin globular head domain of group-2 influenza viruses circulating throughout the population between 1997 and 2007. PMID:26512723

  12. An Anti-Influenza Virus Antibody Inhibits Viral Infection by Reducing Nucleus Entry of Influenza Nucleoprotein

    PubMed Central

    Yoon, Aerin; Yi, Kye Sook; Chang, So Young; Kim, Sung Hwan; Song, Manki; Choi, Jung Ah; Bourgeois, Melissa; Hossain, M. Jaber; Chen, Li-Mei; Donis, Ruben O.; Kim, Hyori; Lee, Yujean; Hwang, Do Been; Min, Ji-Young; Chang, Shin Jae; Chung, Junho

    2015-01-01

    To date, four main mechanisms mediating inhibition of influenza infection by anti-hemagglutinin antibodies have been reported. Anti-globular-head-domain antibodies block either influenza virus receptor binding to the host cell or progeny virion release from the host cell. Anti-stem region antibodies hinder the membrane fusion process or induce antibody-dependent cytotoxicity to infected cells. In this study we identified a human monoclonal IgG1 antibody (CT302), which does not inhibit both the receptor binding and the membrane fusion process but efficiently reduced the nucleus entry of viral nucleoprotein suggesting a novel inhibition mechanism of viral infection by antibody. This antibody binds to the subtype-H3 hemagglutinin globular head domain of group-2 influenza viruses circulating throughout the population between 1997 and 2007. PMID:26512723

  13. Vaccine Reduces HPV Infections in Young Men

    Cancer.gov

    An international randomized clinical trial has shown that the vaccine Gardasil can reduce the incidence of anogenital human papillomavirus (HPV) infections in young men 16 to 26 years of age at the time of vaccination.

  14. The vaccinia virus E6 protein influences virion protein localization during virus assembly

    PubMed Central

    Condit, Richard C.; Moussatche, Nissin

    2015-01-01

    Vaccinia virus mutants in which expression of the virion core protein gene E6R is repressed are defective in virion morphogenesis. E6 deficient infections fail to properly package viroplasm into viral membranes, resulting in an accumulation of empty immature virions and large aggregates of viroplasm. We have used immunogold electron microscopy and immunofluorescence confocal microscopy to assess the intracellular localization of several virion structural proteins and enzymes during E6R mutant infections. We find that during E6R mutant infections virion membrane proteins and virion transcription enzymes maintain a normal localization within viral factories while several major core and lateral body proteins accumulate in aggregated virosomes. The results support a model in which vaccinia virions are assembled from at least three substructures, the membrane, the viroplasm and a “pre-nucleocapsid”, and that the E6 protein is essential for maintaining proper localization of the seven-protein complex and the viroplasm during assembly. PMID:25863879

  15. Wheat streak mosaic virus infects systemically despite extensive coat protein deletions: identification of virion assembly and cell-to-cell movement determinants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Viral coat proteins function in virion assembly and virus biology in a tightly coordinated manner with a role for virtually every amino acid. In this study, we demonstrated that the coat protein (CP) of Wheat streak mosaic virus (WSMV) (genus Tritimovirus; family Potyviridae) is unusually tolerant o...

  16. Using PGD to reduce surgical infection risk.

    PubMed

    Archyangelio, Annesha; Shakhon, Amritpal

    Patients with spinal injuries are at increased risk of surgical site infection due to increased numbers of comorbidities and prolonged surgical procedures. This article describes the impact of a patient group direction that was used in a pre-operative assessment clinic to provide Staphylococcus aureus decolonisation to patients with a spinal injury who required prophylaxis. A post-implementation audit revealed that, in the main, staff and patients adhered to the direction, and infection rates were reduced.

  17. Cytomegalovirus UL103 controls virion and dense body egress.

    PubMed

    Ahlqvist, Jenny; Mocarski, Edward

    2011-05-01

    Human cytomegalovirus UL103 encodes a tegument protein that is conserved across herpesvirus subgroups. Mutant viruses lacking this gene product exhibit dramatically reduced accumulation of cell-free virus progeny and poor cell-to-cell spread. Given that viral proteins and viral DNA accumulate with normal kinetics in cells infected with mutant virus, UL103 appears to function during the late phase of replication, playing a critical role in egress of capsidless dense bodies and virions. Few dense bodies were observed in the extracellular space in mutant virus-infected cells in the presence or absence of the DNA encapsidation inhibitor 2-bromo-5,6-dichloro-1-(β-d-ribofuranosyl)benzimidazole. Upon reversal of encapsidation inhibition, UL103 had a striking impact on accumulation of cell-free virus, but not on accumulation of cell-associated virus. Thus, UL103 plays a novel and important role during maturation, regulating virus particle and dense body egress from infected cells.

  18. M2BP inhibits HIV-1 virion production in a vimentin filaments-dependent manner

    PubMed Central

    Wang, Qin; Zhang, Xiaolin; Han, Yuling; Wang, Xinlu; Gao, Guangxia

    2016-01-01

    M2BP (also called 90K) is an interferon-stimulated gene product that is upregulated in HIV-1 infection. A recent study revealed that M2BP reduces the infectivity of HIV-1 by inhibiting the processing of the viral envelope protein. Here we report that in addition to reducing viral infectivity, M2BP inhibits HIV-1 virion production. We provide evidence showing that M2BP inhibits HIV-1 Gag trafficking to the plasma membrane in a vimentin-dependent manner. When vimentin filaments were collapsed by treating cells with acrylamide or by overexpression of a dominant-negative mutant of vimentin, M2BP inhibition of HIV-1 virion production was significantly relieved. We further show that M2BP interacts with both HIV-1 Gag and vimentin and thereby mediates their interactions. We propose that M2BP traps HIV-1 Gag to vimentin filaments to inhibit the transportation of HIV-1 Gag to the plasma membrane. These findings uncover a novel mechanism by which a host antiviral factor inhibits HIV-1 virion production. PMID:27604950

  19. M2BP inhibits HIV-1 virion production in a vimentin filaments-dependent manner.

    PubMed

    Wang, Qin; Zhang, Xiaolin; Han, Yuling; Wang, Xinlu; Gao, Guangxia

    2016-01-01

    M2BP (also called 90K) is an interferon-stimulated gene product that is upregulated in HIV-1 infection. A recent study revealed that M2BP reduces the infectivity of HIV-1 by inhibiting the processing of the viral envelope protein. Here we report that in addition to reducing viral infectivity, M2BP inhibits HIV-1 virion production. We provide evidence showing that M2BP inhibits HIV-1 Gag trafficking to the plasma membrane in a vimentin-dependent manner. When vimentin filaments were collapsed by treating cells with acrylamide or by overexpression of a dominant-negative mutant of vimentin, M2BP inhibition of HIV-1 virion production was significantly relieved. We further show that M2BP interacts with both HIV-1 Gag and vimentin and thereby mediates their interactions. We propose that M2BP traps HIV-1 Gag to vimentin filaments to inhibit the transportation of HIV-1 Gag to the plasma membrane. These findings uncover a novel mechanism by which a host antiviral factor inhibits HIV-1 virion production. PMID:27604950

  20. The vaccinia virus fusion inhibitor proteins SPI-3 (K2) and HA (A56) expressed by infected cells reduce the entry of superinfecting virus.

    PubMed

    Turner, Peter C; Moyer, Richard W

    2008-10-25

    The orthopoxvirus SPI-3 (K2) and A56 (hemagglutinin, HA) proteins interact and together prevent cell-cell fusion. SPI-3/A56 has been proposed to prevent the superinfection of previously infected cells by reducing virus-cell fusion. Binding of mature virions of vaccinia virus (VV) to VV-infected cells was unaffected by SPI-3 or A56 on the surface of infected cells. Entry of VV into infected cells was assessed using VV-P(T7)-luc carrying the luciferase reporter under T7 control. Cells infected with VV or cowpox virus (CPV) expressing T7 RNA polymerase and lacking SPI-3 and/or A56 were superinfected with VV-P(T7)-luc, and luciferase activity was measured. Inactivation of SPI-3 or A56 from the pre-infecting virus resulted in greater luciferase expression from the superinfecting VV-P(T7)-luc. Antibody against SPI-3 present during infection with wild-type CPV-T7 increased luciferase expression from superinfecting VV-P(T7)-luc. The SPI-3/A56 complex on the infected cell surface therefore appears to reduce the entry of virions into infected cells.

  1. The vaccinia virus fusion inhibitor proteins SPI-3 (K2) and HA (A56) expressed by infected cells reduce the entry of superinfecting virus

    SciTech Connect

    Turner, Peter C. Moyer, Richard W.

    2008-10-25

    The orthopoxvirus SPI-3 (K2) and A56 (hemagglutinin, HA) proteins interact and together prevent cell-cell fusion. SPI-3/A56 has been proposed to prevent the superinfection of previously infected cells by reducing virus-cell fusion. Binding of mature virions of vaccinia virus (VV) to VV-infected cells was unaffected by SPI-3 or A56 on the surface of infected cells. Entry of VV into infected cells was assessed using VV-P{sub T7}-luc carrying the luciferase reporter under T7 control. Cells infected with VV or cowpox virus (CPV) expressing T7 RNA polymerase and lacking SPI-3 and/or A56 were superinfected with VV-P{sub T7}-luc, and luciferase activity was measured. Inactivation of SPI-3 or A56 from the pre-infecting virus resulted in greater luciferase expression from the superinfecting VV-P{sub T7}-luc. Antibody against SPI-3 present during infection with wild-type CPV-T7 increased luciferase expression from superinfecting VV-P{sub T7}-luc. The SPI-3/A56 complex on the infected cell surface therefore appears to reduce the entry of virions into infected cells.

  2. Glutathione is required for efficient production of infectious picornavirus virions

    SciTech Connect

    Smith, Allen D. . E-mail: smitha@ba.ars.usda.gov; Dawson, Harry . E-mail: dawsonh@ba.ars.usda.gov

    2006-09-30

    Glutathione is an intracellular reducing agent that helps maintain the redox potential of the cell and is important for immune function. The drug L-buthionine sulfoximine (BSO) selectively inhibits glutathione synthesis. Glutathione has been reported to block replication of HIV, HSV-1, and influenza virus, whereas cells treated with BSO exhibit increased replication of Sendai virus. Pre-treatment of HeLa cell monolayers with BSO inhibited replication of CVB3, CVB4, and HRV14 with viral titers reduced by approximately 6, 5, and 3 log{sub 1}, respectively. The addition of glutathione ethyl ester, but not dithiothreitol or 2-mercaptoethanol, to the culture medium reversed the inhibitory effect of BSO. Viral RNA and protein synthesis were not inhibited by BSO treatment. Fractionation of lysates from CVB3-infected BSO-treated cells on cesium chloride and sucrose gradients revealed that empty capsids but not mature virions were being produced. The levels of the 5S and 14S assembly intermediates, however, were not affected by BSO treatment. These results demonstrate that glutathione is important for production of mature infectious picornavirus virions.

  3. RNAs extracted from herpes simplex virus 1 virions: apparent selectivity of viral but not cellular RNAs packaged in virions.

    PubMed

    Sciortino, M T; Suzuki, M; Taddeo, B; Roizman, B

    2001-09-01

    Following the lead of recent studies on the presence of RNA in virions of human cytomegalovirus, we investigated the presence and identity of RNAs from purified virions of herpes simple virus 1. To facilitate these studies, we designed primers for all known open reading frames (ORFs) and also constructed cDNA arrays containing probes designed to detect all known transcripts. In the first series of experiments, labeled DNA made by reverse transcription of poly(A)(+) RNA extracted from infected HEp-2 or rabbit skin cells hybridized to all but two of the probes in the cDNA array. A similar analysis of the RNA extracted from purified extracellular virions derived from infected HEp-2 cells hybridized to probes representing 24 of the ORFs. In the second series of analyses, we reverse transcribed and amplified by PCR RNAs from purified intracellular or extracellular virions derived from infected HEp-2 or Vero cell lines. The positive RNAs were retested by PCR with and without prior reverse transcription to ensure that the samples tested were free of contaminating DNA. The results were as follows. (i) Only a fraction of viral ORF transcripts were represented in virion RNA, and only nine RNAs (U(L)10, U(L)34/U(L)35, U(L)36, U(L)42, U(L)48, U(L)51, U(S)1/U(S)1.5, U(S)8.5, and U(S)10/U(S)11) were positive in all RT PCR assays. Of these, seven were positive by hybridization to cDNA arrays. (ii) RNA extracted from cells infected with a mutant virus lacking the U(S)8 to U(S)12 genes yielded results similar to those described above, indicating that U(S)11, a known RNA binding protein, does not play a role in packaging RNA in virions. (iii) Cellular RNAs detected in virions were representative of the abundant cellular RNAs. Last, RNA extracted from virions was translated in vitro and the translation products were reacted with antibody to alphaTIF (VIP16). The immune precipitate contained a labeled protein with the apparent molecular weight of alphaTIF, indicating that at least one

  4. Cytoskeletal proteins inside human immunodeficiency virus type 1 virions.

    PubMed Central

    Ott, D E; Coren, L V; Kane, B P; Busch, L K; Johnson, D G; Sowder, R C; Chertova, E N; Arthur, L O; Henderson, L E

    1996-01-01

    We have identified three types of cytoskeletal proteins inside human immunodeficiency virus type 1 (HIV-1) virions by analyzing subtilisin-digested particles. HIV-1 virions were digested with protease, and the treated particles were isolated by sucrose density centrifugation. This method removes both exterior viral proteins and proteins associated with microvesicles that contaminate virion preparations. Since the proteins inside the virion are protected from digestion by the viral lipid envelope, they can be isolated and analyzed after treatment. Experiments presented here demonstrated that this procedure removed more than 95% of the protein associated with microvesicles. Proteins in digested HIV-1(MN) particles from infected H9 and CEM(ss) cell lines were analyzed by high-pressure liquid chromatography, protein sequencing, and immunoblotting. The data revealed that three types of cytoskeletal proteins are present in virions at different concentrations relative to the molar level of Gag: actin (approximately 10 to 15%), ezrin and moesin (approximately 2%), and cofilin (approximately 2 to 10%). Our analysis of proteins within virus particles detected proteolytic fragments of alpha-smooth muscle actin and moesin that were cleaved at sites which might be recognized by HIV-1 protease. These cleavage products are not present in microvesicles from uninfected cells. Therefore, these processed proteins are most probably produced by HIV-1 protease digestion. The presence of these fragments, as well as the incorporation of a few specific cytoskeletal proteins into virions, suggests an active interaction between cytoskeletal and viral proteins. PMID:8892894

  5. Identification of binary interactions between human cytomegalovirus virion proteins.

    PubMed

    Phillips, Stacia L; Bresnahan, Wade A

    2011-01-01

    Human cytomegalovirus (HCMV) virions are composed of a DNA-containing nucleocapsid surrounded by a tegument layer and host-derived lipid envelope studded with virally encoded glycoproteins. These complex virions are estimated to be composed of more than 50 viral proteins. Assembly of HCMV virions is poorly understood, especially with respect to acquisition of the tegument; however, it is thought to involve the stepwise addition of virion components through protein-protein interactions. We sought to identify interactions among HCMV virion proteins using yeast two-hybrid analysis. Using 33 known capsid and tegument proteins, we tested 1,089 pairwise combinations for binary interaction in the two-hybrid assay. We identified 24 interactions among HCMV virion proteins, including 13 novel interactions among tegument proteins and one novel interaction between capsid proteins. Several of these novel interactions were confirmed by coimmunoprecipitation of protein complexes from transfected cells. In addition, we demonstrate three of these interactions in the context of HCMV infection. This study reveals several new protein-protein interactions among HCMV tegument proteins, some of which are likely important for HCMV replication and pathogenesis. PMID:20962080

  6. Herpes simplex virus virion host shutoff function.

    PubMed

    Kwong, A D; Kruper, J A; Frenkel, N

    1988-03-01

    Herpes simplex virus (HSV) virions contain one or more functions which mediate the shutoff of host protein synthesis and the degradation of host mRNA. HSV type 1 (HSV-1) mutants deficient in the virion shutoff of host protein synthesis (vhs mutants) were isolated and were found to be defective in their ability to degrade host mRNA. Furthermore, it was found that viral mRNAs in cells infected with the vhs 1 mutant have a significantly longer functional half-life than viral mRNAs in wild-type virus-infected cells. In the present study we have mapped the vhs1 mutation affecting the virion shutoff of host protein synthesis to a 265-base-pair NruI-XmaIII fragment spanning map coordinates 0.604 to 0.606 of the HSV-1 genome. The mutation(s) affecting the functional half-lives of host mRNA as well as the alpha (immediate-early), beta (early), and gamma (late) viral mRNAs were also mapped within this 265-base-pair fragment. Thus, the shutoff of host protein synthesis is most likely mediated by the same function which decreases the half-life of viral mRNA. The shorter half-life of infected-cell mRNAs may allow a more rapid modulation of viral gene expression in response to changes in the transcription of viral genes. Interestingly, the vhs1 mutation of HSV-1 maps within a region which overlaps the Bg/II-N sequences of HSV-2 DNA shown previously to transform cells in culture. The possible relationship between the transformation and host shutoff functions are discussed.

  7. Herpes simplex virus virion host shutoff function.

    PubMed Central

    Kwong, A D; Kruper, J A; Frenkel, N

    1988-01-01

    Herpes simplex virus (HSV) virions contain one or more functions which mediate the shutoff of host protein synthesis and the degradation of host mRNA. HSV type 1 (HSV-1) mutants deficient in the virion shutoff of host protein synthesis (vhs mutants) were isolated and were found to be defective in their ability to degrade host mRNA. Furthermore, it was found that viral mRNAs in cells infected with the vhs 1 mutant have a significantly longer functional half-life than viral mRNAs in wild-type virus-infected cells. In the present study we have mapped the vhs1 mutation affecting the virion shutoff of host protein synthesis to a 265-base-pair NruI-XmaIII fragment spanning map coordinates 0.604 to 0.606 of the HSV-1 genome. The mutation(s) affecting the functional half-lives of host mRNA as well as the alpha (immediate-early), beta (early), and gamma (late) viral mRNAs were also mapped within this 265-base-pair fragment. Thus, the shutoff of host protein synthesis is most likely mediated by the same function which decreases the half-life of viral mRNA. The shorter half-life of infected-cell mRNAs may allow a more rapid modulation of viral gene expression in response to changes in the transcription of viral genes. Interestingly, the vhs1 mutation of HSV-1 maps within a region which overlaps the Bg/II-N sequences of HSV-2 DNA shown previously to transform cells in culture. The possible relationship between the transformation and host shutoff functions are discussed. Images PMID:2828686

  8. Reducing urinary tract infections in catheterized patients.

    PubMed

    Hardyck, C; Petrinovich, L

    1998-12-01

    To compare the effectiveness of two drainage systems in controlling urinary tract infections (UTIs), 65 elderly home care patients with indwelling urinary catheters participated in a retrospective intervention study. The patients first used a Foley drainable bag (DB) system, followed by a nondrainable one (NDB). Both systems used a Foley catheter. Data were obtained from physicians, nurses, caregivers, and patients regarding the number of UTIs and hospitalizations that occurred when using each system. Using the DB, 65 patients had 1,395 UTIs, 27 of which required hospitalization. Using the NDB, 2 patients had 71 UTIs, 2 of which required hospitalization. The cost for the non-hospitalization UTIs with DBs was estimated at $1,153,665 compared to $57,890 with NDBs. The hospital costs with DBs were estimated at $274,170 and $15,540 with NDBs. Because DBs were used longer than NDBs (mean = 44.4 months and 8.8 months, respectively), patients who used each bag for the same period of time were compared. When these patients used NDBs they had significantly fewer UTIs (56, with one hospitalization for 7 days) than when they used DBs (242, with 10 hospitalizations for 37 days). Although the cost of purchasing the non-replaceable NDBs is greater, the use of NDBs drastically reduced levels of infection as well as the overall cost to maintain catheterized patients.

  9. Bacteriophage Infection of Model Metal Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Weber, K. A.; Bender, K. S.; Gandhi, K.; Coates, J. D.

    2008-12-01

    Microbially-mediated metal reduction plays a significant role controlling contaminant mobility in aqueous, soil, and sedimentary environments. From among environmentally relevant microorganisms mediating metal reduction, Geobacter spp. have been identified as predominant metal-reducing bacteria under acetate- oxidizing conditions. Due to the significance of these bacteria in environmental systems, it is necessary to understand factors influencing their metabolic physiology. Examination of the annotated finished genome sequence of G. sulfurreducens PCA, G. uraniumreducens Rf4, G. metallireduceans GS-15 as well as a draft genome sequence of Geobacter sp. FRC-32 have identified gene sequences of putative bacteriophage origin. Presence of these sequences indicates that these bacteria are susceptible to phage infection. Polymerase chain reaction (PCR) primer sets designed tested for the presence of 12 of 25 annotated phage-like sequences in G. sulfurreducens PCA and 9 of 17 phage-like sequences in FRC- 32. The following genes were successfully amplified in G. sulfurreducens PCA: prophage type transcription regulator, phage-induced endonuclease, phage tail sheath, 2 phage tail proteins, phage protein D, phage base plate protein, phage-related DNA polymerase, integrase, phage transcriptional regulator, and Cro-like transcription regulator. Nine of the following sequences were present in FRC-32: 4 separate phage- related proteins, phage-related tail component, viron core protein, phage Mu protein, phage base plate, and phage tail sheath. In addition to the bioinformatics evidence, incubation of G. sulfurreducens PCA with 1 μg mL-1 mytomycin C (mutagen stimulating prophage induction) during mid-log phase resulted in significant cell lysis relative to cultures that remained unamended. Cell lysis was concurrent with an increase in viral like particles enumerated using epifluorescent microscopy. In addition, samples collected following this lytic event (~44hours) were

  10. Bacteriophage virion-associated peptidoglycan hydrolases: potential new enzybiotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virion-associated peptidoglycan hydrolases (VAPGH) are phage-encoded lytic enzymes that locally degrade the peptidoglycan (PG) of the bacterial cell wall during infection. Their action usually generates a small hole through which the phage tail crosses the cell envelope to inject the phage genetic m...

  11. Protein in Breast Milk May Reduce Hospital Infections in Preemies

    MedlinePlus

    ... gov/news/fullstory_161498.html Protein in Breast Milk May Reduce Hospital Infections in Preemies Lactoferrin is ... 14, 2016 (HealthDay News) -- A protein in breast milk helps protect premature babies from hospital-acquired infections, ...

  12. Dissociation of polyoma virus by the chelation of calcium ions found associated with purified virions.

    PubMed

    Brady, J N; Winston, V D; Consigli, R A

    1977-09-01

    Analysis of polyoma virions by X-ray fluorometry demonstrated that calcium (Ca2+) was associated with the purified virion. Treatment of purified virions with ethyleneglycol-bis-N,N'-tetraacetic acid (EGTA), which chelates Ca2+, and the reducing agent dithiothreitol caused the virions to dissociate. Electron microscopy revealed that the virions were dissociated to the capsomere level. Incubation of polyoma virions with 150 mM NaCl, 10 mM EGTA, and 3 mM dithiothreitol was optimum for the dissociation reaction. The pH for the dissociation reaction ranged from 7.5 to 10.5. Cesium chloride density gradient centrifugation indicated that both EGTA and dithiothreitol were necessary for dissociation to occur; neither reagent alone dissociated the virus. The major protein product of the dissociated viral particles sedimented at 12S. Relationships between these experiments and the alkaline carbonate-bicarbonate dissociation of polyoma are discussed. PMID:197269

  13. Serial type-specific human papillomavirus (HPV) load measurement allows differentiation between regressing cervical lesions and serial virion productive transient infections.

    PubMed

    Depuydt, Christophe E; Jonckheere, Jef; Berth, Mario; Salembier, Geert M; Vereecken, Annie J; Bogers, Johannes J

    2015-08-01

    Persistent high-risk human papillomavirus (HPV) infection is strongly associated with the development of high-grade cervical intraepithelial neoplasia (CIN) or cancer. Not all persistent infections lead to cancer. Viral load measured at a single time-point is a poor predictor of the natural history of HPV infections. However the profile of viral load evolution over time could distinguish nonprogressive from progressive (carcinogenic) infections. A retrospective natural history study was set up using a Belgian laboratory database including more than 800,000 liquid cytology specimens. All samples were submitted to qPCR identifying E6/E7 genes of 18 HPV types. Viral load changes over time were assessed by the linear regression slope. Database search identified 261 untreated women with persistent type-specific HPV DNA detected (270 infections) in at least three of the last smears for a average period of 3.2 years. Using the coefficient of determination (R²) infections could be subdivided in a latency group (n = 143; R² < 0.85) and a regressing group (n = 127; R² ≥ 0.85). In (≥ 3) serial viral load measurements, serial transient infections with latency is characterized by a nonlinear limited difference in decrease or increase of type-specific viral load (R² < 0.85 and slopes between 2 measurements 0.0010 and -0.0010 HPV copies/cell per day) over a longer period of time (1553 days), whereas regression of a clonal cell population is characterized by a linear (R² ≥ 0.85) decrease (-0.0033 HPV copies/cell per day) over a shorter period of time (708 days; P < 0.001). Using serial HPV type-specific viral load measurements we could for the first time identify regressing CIN2 and CIN3 lesions. Evolution of the viral load is an objective measurable indicator of the natural history of HPV infections and could be used for future triage in HPV-based cervical screening programs.

  14. Human Cytomegalovirus Exploits Interferon-Induced Transmembrane Proteins To Facilitate Morphogenesis of the Virion Assembly Compartment

    PubMed Central

    Xie, Maorong; Xuan, Baoqin; Shan, Jiaoyu; Pan, Deng; Sun, Yamei; Shan, Zhao; Zhang, Jinping; Yu, Dong

    2014-01-01

    ABSTRACT Recently, interferon-induced transmembrane proteins (IFITMs) have been identified to be key effector molecules in the host type I interferon defense system. The invasion of host cells by a large range of RNA viruses is inhibited by IFITMs during the entry step. However, the roles of IFITMs in DNA virus infections have not been studied in detail. In this study, we report that human cytomegalovirus (HCMV), a large human DNA virus, exploits IFITMs to facilitate the formation of the virion assembly compartment (vAC) during infection of human fibroblasts. We found that IFITMs were expressed constitutively in human embryonic lung fibroblasts (MRC5 cells). HCMV infection inhibited IFITM protein accumulation in the later stages of infection. Overexpression of an IFITM protein in MRC5 cells slightly enhanced HCMV production and knockdown of IFITMs by RNA interference reduced the virus titer by about 100-fold on day 8 postinfection, according to the findings of a virus yield assay at a low multiplicity of infection. Virus gene expression and DNA synthesis were not affected, but the typical round structure of the vAC was not formed after the suppression of IFITMs, thereby resulting in defective virion assembly and the production of less infectious virion particles. Interestingly, the replication of herpes simplex virus, a human herpesvirus that is closely related to HCMV, was not affected by the suppression of IFITMs in MRC5 cells. These results indicate that IFITMs are involved in a specific pathway required for HCMV replication. IMPORTANCE HCMV is known to repurpose the interferon-stimulated genes (ISGs) viperin and tetherin to facilitate its replication. Our results expand the range of ISGs that can be exploited by HCMV for its replication. This is also the first report of a proviral function of IFITMs in DNA virus replication. In addition, whereas previous studies showed that IFITMs modulate virus entry, which is a very early stage in the virus life cycle, we

  15. Reduced Risk of Disease During Postsecondary Dengue Virus Infections

    PubMed Central

    Olkowski, Sandra; Forshey, Brett M.; Morrison, Amy C.; Rocha, Claudio; Vilcarromero, Stalin; Halsey, Eric S.; Kochel, Tadeusz J.; Scott, Thomas W.; Stoddard, Steven T.

    2013-01-01

    Background. Antibodies induced by infection with any 1 of 4 dengue virus (DENV) serotypes (DENV-1–4) may influence the clinical outcome of subsequent heterologous infections. To quantify potential cross-protective effects, we estimated disease risk as a function of DENV infection, using data from longitudinal studies performed from September 2006 through February 2011 in Iquitos, Peru, during periods of DENV-3 and DENV-4 transmission. Methods. DENV infections before and during the study period were determined by analysis of serial serum samples with virus neutralization tests. Third and fourth infections were classified as postsecondary infections. Dengue fever cases were detected by door-to-door surveillance for acute febrile illness. Results. Among susceptible participants, 39% (420/1077) and 53% (1595/2997) seroconverted to DENV-3 and DENV-4, respectively. Disease was detected in 7% of DENV-3 infections and 10% of DENV-4 infections. Disease during postsecondary infections was reduced by 93% for DENV-3 and 64% for DENV-4, compared with primary and secondary infections. Despite lower disease rates, postsecondary infections constituted a significant proportion of apparent infections (14% [for DENV-3 infections], 45% [for DENV-4 infections]). Conclusions. Preexisting heterotypic antibodies markedly reduced but did not eliminate the risk of disease in this study population. These results improve understanding of how preinfection history can be associated with dengue outcomes and DENV transmission dynamics. PMID:23776195

  16. Reducing infections through nanotechnology and nanoparticles

    PubMed Central

    Taylor, Erik; Webster, Thomas J

    2011-01-01

    The expansion of bacterial antibiotic resistance is a growing problem today. When medical devices are inserted into the body, it becomes especially difficult for the body to clear robustly adherent antibiotic-resistant biofilm infections. In addition, concerns about the spread of bacterial genetic tolerance to antibiotics, such as that found in multiple drug-resistant Staphylococcus aureus (MRSA), have significantly increased of late. As a growing direction in biomaterial design, nanomaterials (materials with at least one dimension less than 100 nm) may potentially prevent bacterial functions that lead to infections. As a first step in this direction, various nanoparticles have been explored for improving bacteria and biofilm penetration, generating reactive oxygen species, and killing bacteria, potentially providing a novel method for fighting infections that is nondrug related. This review article will first examine in detail the mechanisms and applications of some of these nanoparticles, then follow with some recent material designs utilizing nanotechnology that are centered on fighting medical device infections. PMID:21796248

  17. Cellular Proteins Associated with the Interior and Exterior of Vesicular Stomatitis Virus Virions

    PubMed Central

    Moerdyk-Schauwecker, Megan; Hwang, Sun-Il; Grdzelishvili, Valery Z.

    2014-01-01

    Virus particles (virions) often contain not only virus-encoded but also host-encoded proteins. Some of these host proteins are enclosed within the virion structure, while others, in the case of enveloped viruses, are embedded in the host-derived membrane. While many of these host protein incorporations are likely accidental, some may play a role in virus infectivity, replication and/or immunoreactivity in the next host. Host protein incorporations may be especially important in therapeutic applications where large numbers of virus particles are administered. Vesicular stomatitis virus (VSV) is the prototypic rhabdovirus and a candidate vaccine, gene therapy and oncolytic vector. Using mass spectrometry, we previously examined cell type dependent host protein content of VSV virions using intact (“whole”) virions purified from three cell lines originating from different species. Here we aimed to determine the localization of host proteins within the VSV virions by analyzing: i) whole VSV virions; and ii) whole VSV virions treated with Proteinase K to remove all proteins outside the viral envelope. A total of 257 proteins were identified, with 181 identified in whole virions and 183 identified in Proteinase K treated virions. Most of these proteins have not been previously shown to be associated with VSV. Functional enrichment analysis indicated the most overrepresented categories were proteins associated with vesicles, vesicle-mediated transport and protein localization. Using western blotting, the presence of several host proteins, including some not previously shown in association with VSV (such as Yes1, Prl1 and Ddx3y), was confirmed and their relative quantities in various virion fractions determined. Our study provides a valuable inventory of virion-associated host proteins for further investigation of their roles in the replication cycle, pathogenesis and immunoreactivity of VSV. PMID:25105980

  18. Cellular proteins associated with the interior and exterior of vesicular stomatitis virus virions.

    PubMed

    Moerdyk-Schauwecker, Megan; Hwang, Sun-Il; Grdzelishvili, Valery Z

    2014-01-01

    Virus particles (virions) often contain not only virus-encoded but also host-encoded proteins. Some of these host proteins are enclosed within the virion structure, while others, in the case of enveloped viruses, are embedded in the host-derived membrane. While many of these host protein incorporations are likely accidental, some may play a role in virus infectivity, replication and/or immunoreactivity in the next host. Host protein incorporations may be especially important in therapeutic applications where large numbers of virus particles are administered. Vesicular stomatitis virus (VSV) is the prototypic rhabdovirus and a candidate vaccine, gene therapy and oncolytic vector. Using mass spectrometry, we previously examined cell type dependent host protein content of VSV virions using intact ("whole") virions purified from three cell lines originating from different species. Here we aimed to determine the localization of host proteins within the VSV virions by analyzing: i) whole VSV virions; and ii) whole VSV virions treated with Proteinase K to remove all proteins outside the viral envelope. A total of 257 proteins were identified, with 181 identified in whole virions and 183 identified in Proteinase K treated virions. Most of these proteins have not been previously shown to be associated with VSV. Functional enrichment analysis indicated the most overrepresented categories were proteins associated with vesicles, vesicle-mediated transport and protein localization. Using western blotting, the presence of several host proteins, including some not previously shown in association with VSV (such as Yes1, Prl1 and Ddx3y), was confirmed and their relative quantities in various virion fractions determined. Our study provides a valuable inventory of virion-associated host proteins for further investigation of their roles in the replication cycle, pathogenesis and immunoreactivity of VSV.

  19. mRNA decay during herpes simplex virus (HSV) infections: mutations that affect translation of an mRNA influence the sites at which it is cleaved by the HSV virion host shutoff (Vhs) protein.

    PubMed

    Shiflett, Lora A; Read, G Sullivan

    2013-01-01

    During lytic infections, the herpes simplex virus (HSV) virion host shutoff (Vhs) endoribonuclease degrades many host and viral mRNAs. Within infected cells it cuts mRNAs at preferred sites, including some in regions of translation initiation. Vhs binds the translation initiation factors eIF4H, eIF4AI, and eIF4AII, suggesting that its mRNA degradative function is somehow linked to translation. To explore how Vhs is targeted to preferred sites, we examined the in vitro degradation of a target mRNA in rabbit reticulocyte lysates containing in vitro-translated Vhs. Vhs caused rapid degradation of mRNAs beginning with cleavages at sites in the first 250 nucleotides, including a number near the start codon and in the 5' untranslated region. Ligation of the ends to form a circular mRNA inhibited Vhs cleavage at the same sites at which it cuts capped linear molecules. This was not due to an inability to cut any circular RNA, since Vhs cuts circular mRNAs containing an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) at the same sites as linear molecules with the IRES. Cutting linear mRNAs at preferred sites was augmented by the presence of a 5' cap. Moreover, mutations that altered the 5' proximal AUG abolished Vhs cleavage at nearby sites, while mutations that changed sequences surrounding the AUG to improve their match to the Kozak consensus sequence enhanced Vhs cutting near the start codon. The results indicate that mutations in an mRNA that affect its translation affect the sites at which it is cut by Vhs and suggest that Vhs is directed to its preferred cut sites during translation initiation.

  20. mRNA Decay during Herpes Simplex Virus (HSV) Infections: Mutations That Affect Translation of an mRNA Influence the Sites at Which It Is Cleaved by the HSV Virion Host Shutoff (Vhs) Protein

    PubMed Central

    Shiflett, Lora A.

    2013-01-01

    During lytic infections, the herpes simplex virus (HSV) virion host shutoff (Vhs) endoribonuclease degrades many host and viral mRNAs. Within infected cells it cuts mRNAs at preferred sites, including some in regions of translation initiation. Vhs binds the translation initiation factors eIF4H, eIF4AI, and eIF4AII, suggesting that its mRNA degradative function is somehow linked to translation. To explore how Vhs is targeted to preferred sites, we examined the in vitro degradation of a target mRNA in rabbit reticulocyte lysates containing in vitro-translated Vhs. Vhs caused rapid degradation of mRNAs beginning with cleavages at sites in the first 250 nucleotides, including a number near the start codon and in the 5′ untranslated region. Ligation of the ends to form a circular mRNA inhibited Vhs cleavage at the same sites at which it cuts capped linear molecules. This was not due to an inability to cut any circular RNA, since Vhs cuts circular mRNAs containing an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) at the same sites as linear molecules with the IRES. Cutting linear mRNAs at preferred sites was augmented by the presence of a 5′ cap. Moreover, mutations that altered the 5′ proximal AUG abolished Vhs cleavage at nearby sites, while mutations that changed sequences surrounding the AUG to improve their match to the Kozak consensus sequence enhanced Vhs cutting near the start codon. The results indicate that mutations in an mRNA that affect its translation affect the sites at which it is cut by Vhs and suggest that Vhs is directed to its preferred cut sites during translation initiation. PMID:23077305

  1. The vaccinia virus E6 protein influences virion protein localization during virus assembly

    SciTech Connect

    Condit, Richard C. Moussatche, Nissin

    2015-08-15

    Vaccinia virus mutants in which expression of the virion core protein gene E6R is repressed are defective in virion morphogenesis. E6 deficient infections fail to properly package viroplasm into viral membranes, resulting in an accumulation of empty immature virions and large aggregates of viroplasm. We have used immunogold electron microscopy and immunofluorescence confocal microscopy to assess the intracellular localization of several virion structural proteins and enzymes during E6R mutant infections. We find that during E6R mutant infections virion membrane proteins and virion transcription enzymes maintain a normal localization within viral factories while several major core and lateral body proteins accumulate in aggregated virosomes. The results support a model in which vaccinia virions are assembled from at least three substructures, the membrane, the viroplasm and a “pre-nucleocapsid”, and that the E6 protein is essential for maintaining proper localization of the seven-protein complex and the viroplasm during assembly. - Highlights: • Mutation of E6 disrupts association of viral membranes with viral core proteins • Mutation of E6 does not perturb viral membrane biosynthesis • Mutation of E6 does not perturb localization of viral transcription enzymes • Mutation of E6 causes mis-localization and aggregation of viral core proteins • Vaccinia assembly uses three subassemblies: membranes, viroplasm, prenucleocapsid.

  2. GP3 is a structural component of the PRRSV type II (US) virion

    SciTech Connect

    Lima, M. de; Ansari, I.H.; Das, P.B.; Ku, B.J.; Martinez-Lobo, F.J.; Pattnaik, A.K.; Osorio, F.A.

    2009-07-20

    Glycoprotein 3 (GP3) is a highly glycosylated PRRSV envelope protein which has been reported as being present in the virions of PRRSV type I, while missing in the type II PRRSV (US) virions. We herein present evidence that GP3 is indeed incorporated in the virus particles of a North American strain of PRRSV (FL12), at a density that is consistent with the minor structural role assigned to GP3 in members of the Arterivirus genus. Two 15aa peptides corresponding to two different immunodominant linear epitopes of GP3 derived from the North American strain of PRRSV (FL12) were used as antigen to generate a rabbit monospecific antiserum to this protein. The specificity of this anti-GP3 antiserum was confirmed by radioimmunoprecipitation (RIP) assay using BHK-21 cells transfected with GP3 expressing plasmid, MARC-145 cells infected with FL12 PRRSV, as well as by confocal microscopy on PRRSV-infected MARC-145 cells. To test if GP3 is a structural component of the virion, {sup 35}S-labelled PRRSV virions were pelleted through a 30% sucrose cushion, followed by a second round of purification on a sucrose gradient (20-60%). Virions were detected in specific gradient fractions by radioactive counts and further confirmed by viral infectivity assay in MARC 145 cells. The GP3 was detected in gradient fractions containing purified virions by RIP using anti-GP3 antiserum. Predictably, the GP3 was less abundant in purified virions than other major structural envelope proteins such as GP5 and M. Further evidence of the presence of GP3 at the level of PRRSV FL12 envelope was obtained by immunogold staining of purified virions from the supernatant of infected cells with anti-GP3 antiserum. Taken together, these results indicate that GP3 is a minor structural component of the PRRSV type II (FL12 strain) virion, as had been previously described for PRRSV type I.

  3. Reducing periprosthetic joint infection: what really counts?

    PubMed Central

    SOLARINO, GIUSEPPE; ABATE, ANTONELLA; VICENTI, GIOVANNI; SPINARELLI, ANTONIO; PIAZZOLLA, ANDREA; MORETTI, BIAGIO

    2015-01-01

    Periprosthetic joint infection (PJI) remains one of the most challenging complications after joint arthroplasty. Despite improvements in surgical techniques and in the use of antibiotic prophylaxis, it remains a major cause of implant failure and need for revision. PJI is associated with both human host-related and bacterial agent-related factors that can interact in all the phases of the procedure (preoperative, intraoperative and postoperative). Prevention is the first strategy to implement in order to minimize this catastrophic complication. The present review focuses on the preoperative period, and on what to do once risk factors are fully understood and have been identified. PMID:26904527

  4. Nothing to sneeze at: a dynamic and integrative computational model of an influenza A virion.

    PubMed

    Reddy, Tyler; Shorthouse, David; Parton, Daniel L; Jefferys, Elizabeth; Fowler, Philip W; Chavent, Matthieu; Baaden, Marc; Sansom, Mark S P

    2015-03-01

    The influenza virus is surrounded by an envelope composed of a lipid bilayer and integral membrane proteins. Understanding the structural dynamics of the membrane envelope provides biophysical insights into aspects of viral function, such as the wide-ranging survival times of the virion in different environments. We have combined experimental data from X-ray crystallography, nuclear magnetic resonance spectroscopy, cryo-electron microscopy, and lipidomics to build a model of the intact influenza A virion. This is the basis of microsecond-scale coarse-grained molecular dynamics simulations of the virion, providing simulations at different temperatures and with varying lipid compositions. The presence of the Forssman glycolipid alters a number of biophysical properties of the virion, resulting in reduced mobility of bilayer lipid and protein species. Reduced mobility in the virion membrane may confer physical robustness to changes in environmental conditions. Our simulations indicate that viral spike proteins do not aggregate and thus are competent for multivalent immunoglobulin G interactions.

  5. Mutations in the catalytic core or the C-terminus of murine leukemia virus (MLV) integrase disrupt virion infectivity and exert diverse effects on reverse transcription

    SciTech Connect

    Steinrigl, Adolf; Nosek, Dagmara; Ertl, Reinhard; Guenzburg, Walter H.; Salmons, Brian; Klein, Dieter . E-mail: dieter.klein@vu-wien.ac.at

    2007-05-25

    Understanding of the structures and functions of the retroviral integrase (IN), a key enzyme in the viral replication cycle, is essential for developing antiretroviral treatments and facilitating the development of safer gene therapy vehicles. Thus, four MLV IN-mutants were constructed in the context of a retroviral vector system, harbouring either a substitution in the catalytic centre, deletions in the C-terminus, or combinations of both modifications. IN-mutants were tested for their performance in different stages of the viral replication cycle: RNA-packaging; RT-activity; transient and stable infection efficiency; dynamics of reverse transcription and nuclear entry. All mutant vectors packaged viral RNA with wild-type efficiencies and displayed only slight reductions in RT-activity. Deletion of either the IN C-terminus alone, or in addition to part of the catalytic domain exerted contrasting effects on intracellular viral DNA levels, implying that IN influences reverse transcription in more than one direction.

  6. Virus factories of cauliflower mosaic virus are virion reservoirs that engage actively in vector transmission.

    PubMed

    Bak, Aurélie; Gargani, Daniel; Macia, Jean-Luc; Malouvet, Enrick; Vernerey, Marie-Stéphanie; Blanc, Stéphane; Drucker, Martin

    2013-11-01

    Cauliflower mosaic virus (CaMV) forms two types of inclusion bodies within infected plant cells: numerous virus factories, which are the sites for viral replication and virion assembly, and a single transmission body (TB), which is specialized for virus transmission by aphid vectors. The TB reacts within seconds to aphid feeding on the host plant by total disruption and redistribution of its principal component, the viral transmission helper protein P2, onto microtubules throughout the cell. At the same time, virions also associate with microtubules. This redistribution of P2 and virions facilitates transmission and is reversible; the TB reforms within minutes after vector departure. Although some virions are present in the TB before disruption, their subsequent massive accumulation on the microtubule network suggests that they also are released from virus factories. Using drug treatments, mutant viruses, and exogenous supply of viral components to infected protoplasts, we show that virions can rapidly exit virus factories and, once in the cytoplasm, accumulate together with the helper protein P2 on the microtubule network. Moreover, we show that during reversion of this phenomenon, virions from the microtubule network can either be incorporated into the reverted TB or return to the virus factories. Our results suggest that CaMV factories are dynamic structures that participate in vector transmission by controlled release and uptake of virions during TB reaction.

  7. Virus factories of cauliflower mosaic virus are virion reservoirs that engage actively in vector transmission.

    PubMed

    Bak, Aurélie; Gargani, Daniel; Macia, Jean-Luc; Malouvet, Enrick; Vernerey, Marie-Stéphanie; Blanc, Stéphane; Drucker, Martin

    2013-11-01

    Cauliflower mosaic virus (CaMV) forms two types of inclusion bodies within infected plant cells: numerous virus factories, which are the sites for viral replication and virion assembly, and a single transmission body (TB), which is specialized for virus transmission by aphid vectors. The TB reacts within seconds to aphid feeding on the host plant by total disruption and redistribution of its principal component, the viral transmission helper protein P2, onto microtubules throughout the cell. At the same time, virions also associate with microtubules. This redistribution of P2 and virions facilitates transmission and is reversible; the TB reforms within minutes after vector departure. Although some virions are present in the TB before disruption, their subsequent massive accumulation on the microtubule network suggests that they also are released from virus factories. Using drug treatments, mutant viruses, and exogenous supply of viral components to infected protoplasts, we show that virions can rapidly exit virus factories and, once in the cytoplasm, accumulate together with the helper protein P2 on the microtubule network. Moreover, we show that during reversion of this phenomenon, virions from the microtubule network can either be incorporated into the reverted TB or return to the virus factories. Our results suggest that CaMV factories are dynamic structures that participate in vector transmission by controlled release and uptake of virions during TB reaction. PMID:24006440

  8. Getting IN on Viral RNA Condensation and Virion Maturation.

    PubMed

    Freed, Eric O

    2016-08-25

    The retroviral enzyme integrase plays an essential role in the virus replication cycle by catalyzing the covalent insertion of newly synthesized viral DNA into the host cell chromosome early after infection. Now, Kessl et al. report a second function of integrase: binding to the viral RNA genome in virion particles late in the virus replication cycle to promote particle maturation. PMID:27565339

  9. Spacecraft Environment May Reduce Resistance To Infection

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Ott, C. Mark; Castro, V. A.; Leal, Melanie; Mehta, Satish K.

    2006-01-01

    conditions. Data indicates that space flight is a unique stress environment that may produce stress-induced changes in the host-microbe relationship resulting in increased risk of infection.

  10. Reducing uncertainty in within-host parameter estimates of influenza infection by measuring both infectious and total viral load.

    PubMed

    Petrie, Stephen M; Guarnaccia, Teagan; Laurie, Karen L; Hurt, Aeron C; McVernon, Jodie; McCaw, James M

    2013-01-01

    For in vivo studies of influenza dynamics where within-host measurements are fit with a mathematical model, infectivity assays (e.g. 50% tissue culture infectious dose; TCID50) are often used to estimate the infectious virion concentration over time. Less frequently, measurements of the total (infectious and non-infectious) viral particle concentration (obtained using real-time reverse transcription-polymerase chain reaction; rRT-PCR) have been used as an alternative to infectivity assays. We investigated the degree to which measuring both infectious (via TCID50) and total (via rRT-PCR) viral load allows within-host model parameters to be estimated with greater consistency and reduced uncertainty, compared with fitting to TCID50 data alone. We applied our models to viral load data from an experimental ferret infection study. Best-fit parameter estimates for the "dual-measurement" model are similar to those from the TCID50-only model, with greater consistency in best-fit estimates across different experiments, as well as reduced uncertainty in some parameter estimates. Our results also highlight how variation in TCID50 assay sensitivity and calibration may hinder model interpretation, as some parameter estimates systematically vary with known uncontrolled variations in the assay. Our techniques may aid in drawing stronger quantitative inferences from in vivo studies of influenza virus dynamics.

  11. A phenyl-thiadiazolylidene-amine derivative ejects zinc from retroviral nucleocapsid zinc fingers and inactivates HIV virions

    PubMed Central

    2012-01-01

    Background Sexual acquisition of the human immunodeficiency virus (HIV) through mucosal transmission may be prevented by using topically applied agents that block HIV transmission from one individual to another. Therefore, virucidal agents that inactivate HIV virions may be used as a component in topical microbicides. Results Here, we have identified 2-methyl-3-phenyl-2H-[1,2,4]thiadiazol-5-ylideneamine (WDO-217) as a low-molecular-weight molecule that inactivates HIV particles. Both HIV-1 and HIV-2 virions pretreated with this compound were unable to infect permissive cells. Moreover, WDO-217 was able to inhibit infections of a wide spectrum of wild-type and drug-resistant HIV-1, including clinical isolates, HIV-2 and SIV strains. Whereas the capture of virus by DC-SIGN was unaffected by the compound, it efficiently prevented the transmission of DC-SIGN-captured virus to CD4+ T-lymphocytes. Interestingly, exposure of virions to WDO-217 reduced the amount of virion-associated genomic RNA as measured by real-time RT-qPCR. Further mechanism-of-action studies demonstrated that WDO-217 efficiently ejects zinc from the zinc fingers of the retroviral nucleocapsid protein NCp7 and inhibits the cTAR destabilization properties of this protein. Importantly, WDO-217 was able to eject zinc from both zinc fingers, even when NCp7 was bound to oligonucleotides, while no covalent interaction between NCp7 and WDO-217 could be observed. Conclusion This compound is a new lead structure that can be used for the development of a new series of NCp7 zinc ejectors as candidate topical microbicide agents. PMID:23146561

  12. Nanoparticle-based flow virometry for the analysis of individual virions.

    PubMed

    Arakelyan, Anush; Fitzgerald, Wendy; Margolis, Leonid; Grivel, Jean-Charles

    2013-09-01

    While flow cytometry has been used to analyze the antigenic composition of individual cells, the antigenic makeup of viral particles is still characterized predominantly in bulk. Here, we describe a technology, "flow virometry," that can be used for antigen detection on individual virions. The technology is based on binding magnetic nanoparticles to virions, staining the virions with monoclonal antibodies, separating the formed complexes with magnetic columns, and characterizing them with flow cytometers. We used this technology to study the distribution of two antigens (HLA-DR and LFA-1) that HIV-1 acquires from infected cells among individual HIV-1 virions. Flow virometry revealed that the antigenic makeup of virions from a single preparation is heterogeneous. This heterogeneity could not be detected with bulk analysis of viruses. Moreover, in two preparations of the same HIV-1 produced by different cells, the distribution of antigens among virions was different. In contrast, HIV-1 of two different HIV-1 genotypes replicating in the same cells became somewhat antigenically similar. This nanotechnology allows the study of virions in bodily fluids without virus propagation and in principle is not restricted to the analysis of HIV, but can be applied to the analysis of the individual surface antigenic makeup of any virus. PMID:23925291

  13. Genome-free hepatitis B virion levels in patient sera as a potential marker to monitor response to antiviral therapy.

    PubMed

    Luckenbaugh, L; Kitrinos, K M; Delaney, W E; Hu, J

    2015-06-01

    Complete virions of hepatitis B virus (HBV) contain a DNA genome that is enclosed in a capsid composed of the HBV core antigen (HBcAg), which is in turn surrounded by a lipid envelope studded with viral surface antigens (HBsAg). In addition, HBV-infected cells release subviral particles composed of HBsAg only (HBsAg 'spheres' and 'filaments') or HBsAg enveloping HBcAg but devoid of viral DNA ('empty virions'). The hepatitis B e antigen (HBeAg), a soluble antigen related to HBcAg, is also secreted in some HBV-infected patients. The goals of this study were to explore the levels of empty virions in HBV-infected patients before and during therapy with the nucleotide analog tenofovir disoproxil fumarate (TDF) that inhibits HBV DNA synthesis and the relationships of empty virions to complete virions, HBsAg and HBeAg. HBV DNA, HBcAg and HBsAg levels were determined in serum samples from 21 patients chronically infected with HBV and enrolled in clinical TDF studies. Serum levels of empty virions were found to exceed levels of DNA-containing virions, often by ≥ 100-fold. Levels of both empty and complete virions varied and were related to the HBeAg status. When HBV DNA replication was suppressed by TDF, empty virion levels remained unchanged in most but were decreased (to the limit of detection) in some patients who also experienced significant decrease or loss of serum HBsAg. In conclusion, empty virions are present in the serum of chronic hepatitis B patients at high levels and may be useful in monitoring response to antiviral therapy.

  14. Genome-free hepatitis B virion levels in patient sera as a potential marker to monitor response to antiviral therapy.

    PubMed

    Luckenbaugh, L; Kitrinos, K M; Delaney, W E; Hu, J

    2015-06-01

    Complete virions of hepatitis B virus (HBV) contain a DNA genome that is enclosed in a capsid composed of the HBV core antigen (HBcAg), which is in turn surrounded by a lipid envelope studded with viral surface antigens (HBsAg). In addition, HBV-infected cells release subviral particles composed of HBsAg only (HBsAg 'spheres' and 'filaments') or HBsAg enveloping HBcAg but devoid of viral DNA ('empty virions'). The hepatitis B e antigen (HBeAg), a soluble antigen related to HBcAg, is also secreted in some HBV-infected patients. The goals of this study were to explore the levels of empty virions in HBV-infected patients before and during therapy with the nucleotide analog tenofovir disoproxil fumarate (TDF) that inhibits HBV DNA synthesis and the relationships of empty virions to complete virions, HBsAg and HBeAg. HBV DNA, HBcAg and HBsAg levels were determined in serum samples from 21 patients chronically infected with HBV and enrolled in clinical TDF studies. Serum levels of empty virions were found to exceed levels of DNA-containing virions, often by ≥ 100-fold. Levels of both empty and complete virions varied and were related to the HBeAg status. When HBV DNA replication was suppressed by TDF, empty virion levels remained unchanged in most but were decreased (to the limit of detection) in some patients who also experienced significant decrease or loss of serum HBsAg. In conclusion, empty virions are present in the serum of chronic hepatitis B patients at high levels and may be useful in monitoring response to antiviral therapy. PMID:25395045

  15. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and parasite Trichodina are common pathogens of cultured fish. The authors conducted a study to evaluate whether treatment of Trichodina parasitized tilapia with formalin would improve fish survival and reduce F. columnare infection in fish. Tilapia parasitized by...

  16. Purification of Herpesvirus Virions and Capsids

    PubMed Central

    Dai, Xinghong; Zhou, Z. Hong

    2016-01-01

    This protocol was designed for large-scale purification of herpesvirus particles by cell culture. Virions and capsids are isolated from extracellular culture media and cell nuclei, respectively. Purity and concentration of the purified samples are usually sufficient for structural studies with cryo electron microscopy and cryo electron tomography. The protocol should also be generally suitable for purifying herpesvirus virions and capsids for other types of studies.

  17. Hydroxyapatite chromatography of phage-display virions.

    PubMed

    Smith, George P; Gingrich, Todd R

    2005-12-01

    Hydroxyapatite column chromatography can be used to purify filamentous bacteriophage--the phage most commonly used for phage display. Virions that have been partially purified from culture supernatant by two cycles of precipitation in 2% polyethylene glycol are adsorbed onto the matrix at a density of at least 7.6 x 10(13) virions (about 3 mg) per milliliter of packed bed volume in phosphate-buffered saline (PBS; 0.15 M NaCl, 5 mM NaH2PO4, pH-adjusted to 7.0 with NaOH). The matrix is washed successively with wash buffer I(150 mM NaCl, 125 mM phosphate, pH 7.0), wash buffer II (2.55 M NaCl, 125 mM phosphate, pH 7.0), and wash buffer I; after which virions are desorbed in desorption buffer (150 mM NaCl, 200 mM phosphate, pH 7.0), and the matrix is stripped with stripping buffer (150 mM NaCl, 1 Mphosphate, pH 7.0). About half of the applied virions are recovered in desorption buffer. Western blot analysis shows that they have undetectable levels of host-derived protein contaminants that are present in the input virions and in virions purified by CsCl equilibrium density gradient centrifugation--the method most commonly used to prepare virions in high purity. Hydroxyapatite chromatography is thus an attractive alternative method for purifying filamentous virions, particularly when the scale is too large for ultracentrifugation to be practical. PMID:16382907

  18. Reducing implant-related infections: active release strategies.

    PubMed

    Hetrick, Evan M; Schoenfisch, Mark H

    2006-09-01

    Despite sterilization and aseptic procedures, bacterial infection remains a major impediment to the utility of medical implants including catheters, artificial prosthetics, and subcutaneous sensors. Indwelling devices are responsible for over half of all nosocomial infections, with an estimate of 1 million cases per year (2004) in the United States alone. Device-associated infections are the result of bacterial adhesion and subsequent biofilm formation at the implantation site. Although useful for relieving associated systemic infections, conventional antibiotic therapies remain ineffective against biofilms. Unfortunately, the lack of a suitable treatment often leaves extraction of the contaminated device as the only viable option for eliminating the biofilm. Much research has focused on developing polymers that resist bacterial adhesion for use as medical device coatings. This tutorial review focuses on coatings that release antimicrobial agents (i.e., active release strategies) for reducing the incidence of implant-associated infection. Following a brief introduction to bacteria, biofilms, and infection, the development and study of coatings that slowly release antimicrobial agents such as antibiotics, silver ions, antibodies, and nitric oxide are covered. The success and limitations of these strategies are highlighted.

  19. Reducing surgical site infection in arthroplasty of the lower limb

    PubMed Central

    Johnson, R.; Jameson, S. S.; Sanders, R. D.; Sargant, N. J.; Muller, S. D.; Meek, R. M. D.; Reed, M. R.

    2013-01-01

    Objectives To review the current best surgical practice and detail a multi-disciplinary approach that could further reduce joint replacement infection. Methods Review of relevant literature indexed in PubMed. Results Surgical site infection is a major complication following arthroplasty. Despite its rarity in contemporary orthopaedic practice, it remains difficult to treat and is costly in terms of both patient morbidity and long-term health care resources. Conclusions Emphasis on education of patients and all members of the health-care team and raising awareness in how to participate in preventative efforts is imperative. PMID:23610703

  20. The herpes simplex virus virion host shutoff function.

    PubMed

    Kwong, A D; Frenkel, N

    1989-11-01

    The virion host shutoff (vhs) function of herpes simplex virus (HSV) limits the expression of genes in the infected cells by destabilizing both host and viral mRNAs. vhs function mutants have been isolated which are defective in their ability to degrade host mRNA. Furthermore, the half-life of viral mRNAs is significantly longer in cells infected with the vhs-1 mutant virus than in cells infected with the wild-type (wt) virus. Recent data have shown that the vhs-1 mutation resides within the open reading frame UL41. We have analyzed the shutoff of host protein synthesis in cells infected with a mixture of the wt HSV-1 (KOS) and the vhs-1 mutant virus. The results of these experiments revealed that (i) the wt virus shutoff activity requires a threshold level of input virions per cell and (ii) the mutant vhs-1 virus protein can irreversibly block the wt virus shutoff activity. These results are consistent with a stoichiometric model in which the wt vhs protein interacts with a cellular factor which controls the half-life of cell mRNA. This wt virus interaction results in the destabilization of both host and viral mRNAs. In contrast, the mutant vhs function interacts with the cellular factor irreversibly, resulting in the increased half-life of both host and viral mRNAs.

  1. Formation of virions is strictly required for turnip yellows virus long-distance movement in plants.

    PubMed

    Hipper, Clémence; Monsion, Baptiste; Bortolamiol-Bécet, Diane; Ziegler-Graff, Véronique; Brault, Véronique

    2014-02-01

    Viral genomic RNA of the Turnip yellows virus (TuYV; genus Polerovirus; family Luteoviridae) is protected in virions formed by the major capsid protein (CP) and the minor component, the readthrough (RT*) protein. Long-distance transport, used commonly by viruses to systemically infect host plants, occurs in phloem sieve elements and two viral forms of transport have been described: virions and ribonucleoprotein (RNP) complexes. With regard to poleroviruses, virions have always been presumed to be the long-distance transport form, but the potential role of RNP complexes has not been investigated. Here, we examined the requirement of virions for polerovirus systemic movement by analysing CP-targeted mutants that were unable to form viral particles. We confirmed that TuYV mutants that cannot encapsidate into virions are not able to reach systemic leaves. To completely discard the possibility that the introduced mutations in CP simply blocked the formation or the movement of RNP complexes, we tested in trans complementation of TuYV CP mutants by providing WT CP expressed in transgenic plants. WT CP was able to facilitate systemic movement of TuYV CP mutants and this observation was always correlated with the formation of virions. This demonstrated clearly that virus particles are essential for polerovirus systemic movement. PMID:24214396

  2. Vaccinia Virus Morphogenesis: A13 Phosphoprotein Is Required for Assembly of Mature Virions

    PubMed Central

    Unger, Bethany; Traktman, Paula

    2004-01-01

    The 70-amino-acid A13L protein is a component of the vaccinia virus membrane. We demonstrate here that the protein is expressed at late times of infection, undergoes phosphorylation at a serine residue(s), and becomes encapsidated in a monomeric form. Phosphorylation is dependent on Ser40, which lies within the proline-rich motif SPPP. Because phosphorylation of the A13 protein is only minimally affected by disruption of the viral F10 kinase or H1 phosphatase, a cellular kinase is likely to be involved. We generated an inducible recombinant in which A13 protein expression is dependent upon the inclusion of tetracycline in the culture medium. Repression of the A13L protein spares the biochemical progression of the viral life cycle but arrests virion morphogenesis. Virion assembly progresses through the formation of immature virions (IVs); however, these virions do not acquire nucleoids, and DNA crystalloids accumulate in the cytoplasm. Further development into intracellular mature virions is blocked, causing a 1,000-fold decrease in the infectious virus yield relative to that obtained in the presence of the inducer. We also determined that the temperature-sensitive phenotype of the viral mutant Cts40 is due to a nucleotide transition within the A13L gene that causes a Thr48→Ile substitution. This substitution disrupts the function of the A13 protein but does not cause thermolability of the protein; at the nonpermissive temperature, virion morphogenesis arrests at the stage of IV formation. The A13L protein, therefore, is part of a newly recognized group of membrane proteins that are dispensable for the early biogenesis of the virion membrane but are essential for virion maturation. PMID:15280497

  3. Botrytis infection warnings in strawberry: reduced enhanced chemical control.

    PubMed

    Van Laer, S; Hauke, K; Meesters, P; Creemers, P

    2005-01-01

    The fungal pathogen Botrytis cinerea is the causal agent of grey mould, the most important fungal fruit rot disease in strawberry in Europe. Currently disease control for grey mould is based on preventive spraying every five to seven days during flowering and harvest. Replacing preventive spraying with applications based on infection warnings can optimize performance and reduce the amount of sprays needed. Success of this approach will depend on the accuracy of the model used to predict disease outbreak. For this reason three infection models (BOTEM, BoWaS, DSS-Italy) were evaluated during the growth seasons of 2003 and 2004. The experiments included June bearing, retarded June bearing and ever bearing strawberries. In all experiments the use of infection models leaded to a reduced number of fungicide applications. However the efficacy of the different models towards the control of B. cinerea also decreased compared to the efficacy obtained with a standard 7 day schedule. Best results were obtained with BOTEM, developed by HRI (Horticultural Research International, East-Malling, UK): 17-60% reduction in fungicide use and an efficacy between 66-93 depending on the growth season, culture practice and the fungicides used. Compared with routine preventive spraying, the Botrytis fruit rot percentage is slightly higher. A higher efficacy with Botrytis infection warnings can only be obtained if infection warnings change from curative to preventive. A retroactive evaluation of a preventive warning system was included. Making use of the 48h weather forecasts supplied by the Royal Meteorological Institute of Belgium (KMI) based on ALADIN for the region of Haspengouw, it was possible to replace 30 up to 100% of the curative application by preventive spraying depending on the experiment and the threshold set for the preventive model.

  4. Proteomics of HCV virions reveals an essential role for the nucleoporin Nup98 in virus morphogenesis.

    PubMed

    Lussignol, Marion; Kopp, Martina; Molloy, Kelly; Vizcay-Barrena, Gema; Fleck, Roland A; Dorner, Marcus; Bell, Kierstin L; Chait, Brian T; Rice, Charles M; Catanese, Maria Teresa

    2016-03-01

    Hepatitis C virus (HCV) is a unique enveloped virus that assembles as a hybrid lipoviral particle by tightly interacting with host lipoproteins. As a result, HCV virions display a characteristic low buoyant density and a deceiving coat, with host-derived apolipoproteins masking viral epitopes. We previously described methods to produce high-titer preparations of HCV particles with tagged envelope glycoproteins that enabled ultrastructural analysis of affinity-purified virions. Here, we performed proteomics studies of HCV isolated from culture media of infected hepatoma cells to define viral and host-encoded proteins associated with mature virions. Using two different affinity purification protocols, we detected four viral and 46 human cellular proteins specifically copurifying with extracellular HCV virions. We determined the C terminus of the mature capsid protein and reproducibly detected low levels of the viral nonstructural protein, NS3. Functional characterization of virion-associated host factors by RNAi identified cellular proteins with either proviral or antiviral roles. In particular, we discovered a novel interaction between HCV capsid protein and the nucleoporin Nup98 at cytosolic lipid droplets that is important for HCV propagation. These results provide the first comprehensive view to our knowledge of the protein composition of HCV and new insights into the complex virus-host interactions underlying HCV infection. PMID:26884193

  5. Coxsackievirus B3 infection reduces female mouse fertility

    PubMed Central

    Shim, Hye Min; Hwang, Ji Young; Lee, Kyung Min; Kim, Yunhwa; Jeong, Daewon; Roh, Jaesook; Choi, Hyeonhae; Hwang, Jung Hye; Park, Hosun

    2015-01-01

    Previously we demonstrated coxsackievirus B3 (CVB3) infection during early gestation as a cause of pregnancy loss. Here, we investigated the impacts of CVB3 infection on female mouse fertility. Coxsackievirus-adenovirus receptor (CAR) expression and CVB3 replication in the ovary were evaluated by immunohistochemistry or reverse transcription-polymerase chain reaction (RT-PCR). CAR was highly expressed in granulosa cells (GCs) and CVB3 replicated in the ovary. Histological analysis showed a significant increase in the number of atretic follicles in the ovaries of CVB3-infected mice (CVBM). Estrous cycle evaluation demonstrated that a higher number of CVBM were in proestrus compared to mock mice (CVBM vs. mock; 61.5%, 28.5%, respectively). Estradiol concentration in GC culture supernatant and serum were measured by an enzyme-linked immunosorbent assay. Baseline and stimulated levels of estradiol in GC were decreased in CVBM, consistent with significantly reduced serum levels in these animals. In addition, aromatase transcript levels in GCs from CVBM were also decreased by 40% relative to the mock. Bone mineral density evaluated by micro-computed tomography was significantly decreased in the CVBM. Moreover, the fertility rate was also significantly decreased for the CVBM compared to the mock (CVBM vs. mock; 20%, 94.7%, respectively). This study suggests that CVB3 infection could interfere with reproduction by disturbing ovarian function and cyclic changes of the uterus. PMID:26062767

  6. Interaction between HeLa cells and adenovirus type 2 virions neutralized by different antisera.

    PubMed Central

    Wohlfart, C E; Svensson, U K; Everitt, E

    1985-01-01

    Three adenovirus type 2-specified immunogens elicited neutralizing antibodies when injected into rabbits; these were the fiber, the hexon, and the penton base. Adenovirus type 2 virions, neutralized by antihexon- or anti-penton base antisera, attached to HeLa cells to the same extent as untreated control virus, and after attachment, neutralized viruses also became sensitive to DNase treatment. A fraction of 75 to 80% of the attached antibody-treated virions penetrated the plasma membrane, which should be compared with an 84 to 88% penetration level in the control series. A majority of the antihexon-neutralized virions was found in intracellular vesicles, as revealed with an electron microscope, but in the case of anti-penton base neutralization, a maximum of 50% of the virions was retained within vesicles, and ca. 30% was free in the cytoplasmic compartment. A value greater than 45% was never obtained for neutralization with a monospecific anti-penton base antiserum, which could imply the existence of alternative pathways for virus penetration into HeLa cells--one of these being sensitive to treatment with anti-penton base antiserum. Antisera containing antifiber specificities efficiently aggregated virions, and the aggregation data mirrored the degree of neutralization. Antifiber-neutralized virions attached to cells to a three- to five times greater extent than untreated control virus, but the former virions had a reduced ability to become sensitive to DNase treatment. Around 15% of the attached antifiber-treated virions was found as large aggregates inside multivesicular bodies or lysosomes. Images PMID:4068145

  7. Getting to Zero: Goal Commitment to Reduce Blood Stream Infections.

    PubMed

    McAlearney, Ann Scheck; Hefner, Jennifer L

    2016-08-01

    While preventing health care-associated infections (HAIs) can save lives and reduce health care costs, efforts designed to eliminate HAIs have had mixed results. Variability in contextual factors such as work culture and management practices has been suggested as a potential explanation for inconsistent results across organizations and interventions. We examine goal-setting as a factor contributing to program outcomes in eight hospitals focused on preventing central line-associated bloodstream infections (CLABSIs). We conducted qualitative case studies to compare higher- and lower-performing hospitals, and explored differences in contextual factors that might contribute to performance variation. We present a goal commitment framework that characterizes factors associated with successful CLABSI program outcomes. Across 194 key informant interviews, internal and external moderators and characteristics of the goal itself differentiated actors' goal commitment at higher- versus lower-performing hospitals. Our findings have implications for organizations struggling to prevent HAIs, as well as informing the broader goal commitment literature.

  8. Modeling of Virion Collisions in Cervicovaginal Mucus Reveals Limits on Agglutination as the Protective Mechanism of Secretory Immunoglobulin A

    PubMed Central

    Chen, Alex; McKinley, Scott A.; Shi, Feng; Wang, Simi; Mucha, Peter J.; Harit, Dimple; Forest, M. Gregory; Lai, Samuel K.

    2015-01-01

    Secretory immunoglobulin A (sIgA), a dimeric antibody found in high quantities in the gastrointestinal mucosa, is broadly associated with mucosal immune protection. A distinguishing feature of sIgA is its ability to crosslink pathogens, thereby creating pathogen/sIgA aggregates that are too large to traverse the dense matrix of mucin fibers in mucus layers overlying epithelial cells and consequently reducing infectivity. Here, we use modeling to investigate this mechanism of “immune exclusion” based on sIgA-mediated agglutination, in particular the potential use of sIgA to agglutinate HIV in cervicovaginal mucus (CVM) and prevent HIV transmission. Utilizing reported data on HIV diffusion in CVM and semen, we simulate HIV collision kinetics in physiologically-thick mucus layers–a necessary first step for sIgA-induced aggregation. We find that even at the median HIV load in semen of acutely infected individuals possessing high viral titers, over 99% of HIV virions will penetrate CVM and reach the vaginal epithelium without colliding with another virion. These findings imply that agglutination is unlikely to be the dominant mechanism of sIgA-mediated protection against HIV or other sexually transmitted pathogens. Rather, we surmise that agglutination is most effective against pathogens either present at exceedingly high concentrations or that possess motility mechanisms other than Brownian diffusion that significantly enhance encounter rates. PMID:26132216

  9. [Sedimentation analysis of the virion RNA of Machupo virus].

    PubMed

    Lukashevich, I S; Lemeshko, N N; Golubev, V P; Stel'makh, T A; Petkevich, A S

    1983-01-01

    Pichinde and Machupo viruses labeled with 3H-uridine were concentrated and purified by different methods. The buoyant density of the viruses was for Pichinde 1.14-1.15 g/cm3 (urographimeter), 1.19 g/cm3 (sucrose), 1.25 g/cm3 (cesium chloride), for Machupo virus 1.25 g/cm3 (cesium chloride). Virion RNAs of Pichinde and Machupo viruses were divided in sucrose concentration gradient into 4 sedimentation classes: 7-10 S, 18 S, 20-22 S, and 28-30 S. Virion 28 S and 18 S RNAs cosedimented with ribosomal cellular RNAs. The RNAs isolated at late stages of infection from the infected cells labeled with 3H-uridine in the presence of actinomycin D (1 microgram/ml) contained two major sedimentation classes of virus-specific molecules: 20-22 S and 30-31 S. Like Pichinde virus, Machupo virus genome is supposed to contain two RNA fragments (30-31 S and 20-22 S) as well as admixtures of ribosomal RNAs.

  10. A Small Molecule Inhibits Virion Attachment to Heparan Sulfate- or Sialic Acid-Containing Glycans

    PubMed Central

    Colpitts, Che C.

    2014-01-01

    ABSTRACT Primary attachment to cellular glycans is a critical entry step for most human viruses. Some viruses, such as herpes simplex virus type 1 (HSV-1) and hepatitis C virus (HCV), bind to heparan sulfate, whereas others, such as influenza A virus (IAV), bind to sialic acid. Receptor mimetics that interfere with these interactions are active against viruses that bind to either heparan sulfate or to sialic acid. However, no molecule that inhibits the attachment of viruses in both groups has yet been identified. Epigallocatechin gallate (EGCG), a green tea catechin, is active against many unrelated viruses, including several that bind to heparan sulfate or to sialic acid. We sought to identify the basis for the broad-spectrum activity of EGCG. Here, we show that EGCG inhibits the infectivity of a diverse group of enveloped and nonenveloped human viruses. EGCG acts directly on the virions, without affecting the fluidity or integrity of the virion envelopes. Instead, EGCG interacts with virion surface proteins to inhibit the attachment of HSV-1, HCV, IAV, vaccinia virus, adenovirus, reovirus, and vesicular stomatitis virus (VSV) virions. We further show that EGCG competes with heparan sulfate for binding of HSV-1 and HCV virions and with sialic acid for binding of IAV virions. Therefore, EGCG inhibits unrelated viruses by a common mechanism. Most importantly, we have identified EGCG as the first broad-spectrum attachment inhibitor. Our results open the possibility for the development of small molecule broad-spectrum antivirals targeting virion attachment. IMPORTANCE This study shows that it is possible to develop a small molecule antiviral or microbicide active against the two largest groups of human viruses: those that bind to glycosaminoglycans and those that bind to sialoglycans. This group includes the vast majority of human viruses, including herpes simplex viruses, cytomegalovirus, influenza virus, poxvirus, hepatitis C virus, HIV, and many others. PMID

  11. Management strategies to reduce risk of postoperative infections

    PubMed Central

    Galor, Anat; Goldhardt, Raquel; Wellik, Sarah R.; Gregori, Ninel Z.; Flynn, Harry W.

    2013-01-01

    Postoperative infections, although rare, are still of great concern to the ophthalmologist. The incidence of post-cataract endophthalmitis is low, with a range of .28 per 1,000 to 2.99 per 1000. In addition to intraoperative considerations such as poor wound construction, vitreous loss, topical anesthesia, and prolonged surgical time, other risk factors include preoperative factors such as a diseased ocular surface and systemic immunosuppression. Potential methods of reducing risk of endophthalmitis after anterior segment surgery are discussed and available literature is summarized. PMID:24319649

  12. Structure and Assembly of TP901-1 Virion Unveiled by Mutagenesis

    PubMed Central

    Douillard, François P.; Mahony, Jennifer; Cambillau, Christian; van Sinderen, Douwe

    2015-01-01

    Bacteriophages of the Siphoviridae family represent the most abundant viral morphology in the biosphere, yet many molecular aspects of their virion structure, assembly and associated functions remain to be unveiled. In this study, we present a comprehensive mutational and molecular analysis of the temperate Lactococcus lactis-infecting phage TP901-1. Fourteen mutations located within the structural module of TP901-1 were created; twelve mutations were designed to prevent full length translation of putative proteins by non-sense mutations, while two additional mutations caused aberrant protein production. Electron microscopy and Western blot analysis of mutant virion preparations, as well as in vitro assembly of phage mutant combinations, revealed the essential nature of many of the corresponding gene products and provided information on their biological function(s). Based on the information obtained, we propose a functional and assembly model of the TP901-1 Siphoviridae virion. PMID:26147978

  13. The detection of defective interfering Rubella virions by a modified hemadsorption technique.

    PubMed

    Pope, D D; Bohn, E M; Van Alstyne, D

    1983-01-01

    Rubella virus (RV) has been titrated in murine fibroblasts in monolayer cultures using a modified hemadsorption assay. Infected monolayers were incubated in the presence of sheep erythrocytes for 24 h: after the tissue culture slides were washed, the hemadsorption foci were clearly visible on microscopic examination. When serial doubling dilutions of virus suspensions were assayed in this way the decline in the number of hemadsorbing units was proportional to the fractional power of the concn. These data suggest that this simple titration of Rubella virus may be useful in the detection of defective interfering (DI) virions in Rubella populations. The detection of DI Rubella virions by more time-consuming and expensive techniques including isopycnic centrifugation, ribonucleic acid extraction, 125I-labelling, polyacrylamide slab gel electrophoresis, and autoradiography have been described. The clinical importance of defective virions and the need for an inexpensive, rapid means of detecting them are discussed.

  14. Expression of the highly conserved vaccinia virus E6 protein is required for virion morphogenesis

    SciTech Connect

    Resch, Wolfgang; Weisberg, Andrea S.; Moss, Bernard

    2009-04-10

    The vaccinia virus E6R gene (VACVWR062) is conserved in all members of the poxvirus family and encodes a protein associated with the mature virion. We confirmed this association and provided evidence for an internal location. An inducible mutant that conditionally expresses E6 was constructed. In the absence of inducer, plaque formation and virus production were severely inhibited in several cell lines, whereas some replication occurred in others. This difference could be due to variation in the stringency of repression, since we could not isolate a stable deletion mutant even in the more 'permissive' cells. Under non-permissive conditions, viral late proteins were synthesized but processing of core proteins was inefficient, indicative of an assembly block. Transmission electron microscopy of sections of cells infected with the mutant in the absence of inducer revealed morphogenetic defects with crescents and empty immature virions adjacent to dense inclusions of viroplasm. Mature virions were infrequent and cores appeared to have lucent centers.

  15. Human cytomegalovirus tegument protein pUL71 is required for efficient virion egress.

    PubMed

    Womack, Andrew; Shenk, Thomas

    2010-01-01

    The human cytomegalovirus virion is composed of a DNA genome packaged in an icosahedral capsid, surrounded by a tegument of protein and RNA, all enclosed within a glycoprotein-studded envelope. Achieving this intricate virion architecture requires a coordinated process of assembly and egress. We show here that pUL71, a component of the virion tegument with a previously uncharacterized function, is required for the virus-induced reorganization of host cell membranes, which is necessary for efficient viral assembly and egress. A mutant that did not express pUL71 was able to efficiently accumulate viral genomes and proteins that were tested but was defective for the production and release of infectious virions. The protein localized to vesicular structures at the periphery of the viral assembly compartment, and during infection with a pUL71-deficient virus, these structures were grossly enlarged and aberrantly contained a cellular marker of late endosomes/lysosomes. Mutant virus preparations exhibited less infectivity per unit genome than wild-type virus preparations, due to aggregation of virus particles and their association with membrane fragments. Finally, mutant virus particles accumulated within the cytoplasm of infected cells and were localized to the periphery of large structures with properties of lysosomes, whose formation was kinetically favored in mutant-virus-infected cells. Together, these observations point to a role for pUL71 in the establishment and/or maintenance of a functional viral assembly compartment that is required for normal virion trafficking and egress from infected cells. PMID:21151777

  16. Culture-independent evaluation of nonenveloped-virus infectivity reduced by free-chlorine disinfection.

    PubMed

    Sano, Daisuke; Ohta, Takatomo; Nakamura, Arata; Nakagomi, Toyoko; Nakagomi, Osamu; Okabe, Satoshi

    2015-04-01

    The inability of molecular detection methods to distinguish disinfected virions from infectious ones has hampered the assessment of infectivity for enteric viruses caused by disinfection practices. In the present study, the reduction of infectivity of murine norovirus S7-PP3 and mengovirus vMC0, surrogates of human noroviruses and enteroviruses, respectively, caused by free-chlorine treatment was characterized culture independently by detecting carbonyl groups on viral capsid protein. The amount of carbonyls on viral capsid protein was evaluated by the proportion of biotinylated virions trapped by avidin-immobilized gel (percent adsorbed). This culture-independent approach demonstrated that the percent adsorbed was significantly correlated with the logarithm of the infectious titer of tested viruses. Taken together with the results of previous reports, the result obtained in this study indicates that the amount of carbonyls on viral capsid protein of four important families of waterborne pathogenic viruses, Astroviridae, Reoviridae, Caliciviridae, and Picornaviridae, is increased in proportion to the received oxidative stress of free chlorine. There was also a significant correlation between the percent adsorbed and the logarithm of the ratio of genome copy number to PFU, which enables estimation of the infectious titer of a subject virus by measuring values of the total genome copy number and the percent adsorbed. The proposed method is applicable when the validation of a 4-log reduction of viruses, a requirement in U.S. EPA guidelines for virus removal from water, is needed along with clear evidence of the oxidation of virus particles with chlorine-based disinfectants.

  17. Culture-Independent Evaluation of Nonenveloped-Virus Infectivity Reduced by Free-Chlorine Disinfection

    PubMed Central

    Ohta, Takatomo; Nakamura, Arata; Nakagomi, Toyoko; Nakagomi, Osamu; Okabe, Satoshi

    2015-01-01

    The inability of molecular detection methods to distinguish disinfected virions from infectious ones has hampered the assessment of infectivity for enteric viruses caused by disinfection practices. In the present study, the reduction of infectivity of murine norovirus S7-PP3 and mengovirus vMC0, surrogates of human noroviruses and enteroviruses, respectively, caused by free-chlorine treatment was characterized culture independently by detecting carbonyl groups on viral capsid protein. The amount of carbonyls on viral capsid protein was evaluated by the proportion of biotinylated virions trapped by avidin-immobilized gel (percent adsorbed). This culture-independent approach demonstrated that the percent adsorbed was significantly correlated with the logarithm of the infectious titer of tested viruses. Taken together with the results of previous reports, the result obtained in this study indicates that the amount of carbonyls on viral capsid protein of four important families of waterborne pathogenic viruses, Astroviridae, Reoviridae, Caliciviridae, and Picornaviridae, is increased in proportion to the received oxidative stress of free chlorine. There was also a significant correlation between the percent adsorbed and the logarithm of the ratio of genome copy number to PFU, which enables estimation of the infectious titer of a subject virus by measuring values of the total genome copy number and the percent adsorbed. The proposed method is applicable when the validation of a 4-log reduction of viruses, a requirement in U.S. EPA guidelines for virus removal from water, is needed along with clear evidence of the oxidation of virus particles with chlorine-based disinfectants. PMID:25681178

  18. Predicting First Traversal Times for Virions and Nanoparticles in Mucus with Slowed Diffusion

    PubMed Central

    Erickson, Austen M.; Henry, Bruce I.; Murray, John M.; Klasse, Per Johan; Angstmann, Christopher N.

    2015-01-01

    Particle-tracking experiments focusing on virions or nanoparticles in mucus have measured mean-square displacements and reported diffusion coefficients that are orders of magnitude smaller than the diffusion coefficients of such particles in water. Accurate description of this subdiffusion is important to properly estimate the likelihood of virions traversing the mucus boundary layer and infecting cells in the epithelium. However, there are several candidate models for diffusion that can fit experimental measurements of mean-square displacements. We show that these models yield very different estimates for the time taken for subdiffusive virions to traverse through a mucus layer. We explain why fits of subdiffusive mean-square displacements to standard diffusion models may be misleading. Relevant to human immunodeficiency virus infection, using computational methods for fractional subdiffusion, we show that subdiffusion in normal acidic mucus provides a more effective barrier against infection than previously thought. By contrast, the neutralization of the mucus by alkaline semen, after sexual intercourse, allows virions to cross the mucus layer and reach the epithelium in a short timeframe. The computed barrier protection from fractional subdiffusion is some orders of magnitude greater than that derived by fitting standard models of diffusion to subdiffusive data. PMID:26153713

  19. [In vitro and in vivo effects of ingavirin on the ultrastructure and infectivity of influenza virus].

    PubMed

    Zarubaev, V V; Beliaevskaia, S V; Sirotkin, A K; Anfimov, P M; Nebol'sin, V E; Kiselev, O I; Reĭkhart, D V

    2011-01-01

    The aim of this investigation was to study the effect of ingavirin on the structure and properties of influenza virions forming in its presence. The infectious activity of the virus and the morphology of the virions were analyzed by titration in cell culture and electron microscopy, respectively. The use of ingavirin was shown to reduce the proportion of morphologically intact virions and to increase that of filamentous and giant particles. No defects of surface glycoproteins were observed. The effect of the drug did not depend on the chosen model of virus replication and it was similarly shown in both cultured human cells and laboratory animals. In MDCK and A549 cells and in the mouse lungs, viral infectious activity was decreased by 1-2 orders of magnitude in relation to a model. The findings suggest that Ingavirin is able to impair the processes of viral morphogenesis, which in turn leads to a reduction in the infectivity of progeny virions.

  20. Ferroportin-encapsulated nanoparticles reduce infection and improve immunity in mice infected with Leishmania major.

    PubMed

    Rafiee, Aras; Riazi-Rad, Farhad; Darabi, Haiedeh; Khaze, Vahid; Javadian, Seifoddin; Ajdary, Soheila; Bahrami, Fariborz; Alimohammadian, Mohammad Hossein

    2014-05-15

    Inoculation of inbred mice by Leishmania major results in two different patterns. C57BL/6 mice display resistance against L. major but BALB/c mice show susceptibility to L. major with visceral infection, anemia and death. In this study, the effects of treatment of L. major-infected BALB/c mice with a ferroportin (Fpn)-encoding construct via nanoparticles were evaluated. A fragment encoding Fpn, a major regulator of iron homeostasis, was amplified and sub-cloned to a GFP expression vector to express Fpn-EGFP protein. This construct was incorporated in nanoparticles of alginate/chitosan polymers and orally administered to L. major-infected BALB/c mice. Blood hematocrit and iron, footpad size, parasite load and concentration of IFNG, IL4 and IL10 by ELISA were measured in the treated and untreated mice. The results indicated that the treated mice had significantly higher hematocrit and iron levels while exhibited significantly lower footpad size and parasite load measurements. Moreover, lower levels of IL4 and IL10 and higher ratios of IFNG/IL4 or IFNG/IL10 were shown in the treated, compared to the untreated mice. In conclusion, treating BALB/c mice infected with L. major with encapsulated Fpn-encoding construct in alginate/chitosan nanoparticles were shown to reduce the infection and improve anemia and immunity in the animal model of leishmaniasis.

  1. Vaccinia extracellular virions enter cells by macropinocytosis and acid-activated membrane rupture

    PubMed Central

    Schmidt, Florian Ingo; Bleck, Christopher Karl Ernst; Helenius, Ari; Mercer, Jason

    2011-01-01

    Vaccinia virus (VACV), the model poxvirus, produces two types of infectious particles: mature virions (MVs) and extracellular virions (EVs). EV particles possess two membranes and therefore require an unusual cellular entry mechanism. By a combination of fluorescence and electron microscopy as well as flow cytometry, we investigated the cellular processes that EVs required to infect HeLa cells. We found that EV particles were endocytosed, and that internalization and infection depended on actin rearrangements, activity of Na+/H+ exchangers, and signalling events typical for the macropinocytic mechanism of endocytosis. To promote their internalization, EVs were capable of actively triggering macropinocytosis. EV infection also required vacuolar acidification, and acid exposure in endocytic vacuoles was needed to disrupt the outer EV membrane. Once exposed, the underlying MV-like particle presumably fused its single membrane with the limiting vacuolar membrane. Release of the viral core into the host cell cytosol allowed for productive infection. PMID:21792173

  2. Vaccinia extracellular virions enter cells by macropinocytosis and acid-activated membrane rupture.

    PubMed

    Schmidt, Florian Ingo; Bleck, Christopher Karl Ernst; Helenius, Ari; Mercer, Jason

    2011-08-31

    Vaccinia virus (VACV), the model poxvirus, produces two types of infectious particles: mature virions (MVs) and extracellular virions (EVs). EV particles possess two membranes and therefore require an unusual cellular entry mechanism. By a combination of fluorescence and electron microscopy as well as flow cytometry, we investigated the cellular processes that EVs required to infect HeLa cells. We found that EV particles were endocytosed, and that internalization and infection depended on actin rearrangements, activity of Na(+)/H(+) exchangers, and signalling events typical for the macropinocytic mechanism of endocytosis. To promote their internalization, EVs were capable of actively triggering macropinocytosis. EV infection also required vacuolar acidification, and acid exposure in endocytic vacuoles was needed to disrupt the outer EV membrane. Once exposed, the underlying MV-like particle presumably fused its single membrane with the limiting vacuolar membrane. Release of the viral core into the host cell cytosol allowed for productive infection. PMID:21792173

  3. Reducing central line infections in pediatric and neonatal patients.

    PubMed

    Li, Simon; Faustino, Edward Vincent S; Golombek, Sergio G

    2013-06-01

    The stakes for the prevention of central line associated bloodstream infections (CLABSIs) have increased dramatically over the past decade. Over the past 10 years, the rate of CLABSI in the pediatric population has dropped markedly due to the significant investment in this initiative. Although there has been a substantial increase in studies on CLABSIs, difficulties in studying CLABSIs have limited the quality of the evidence produced. These difficulties include challenges in the sample size required to complete trials, pressure from external regulatory forces to reduce CLABSI rates, and challenges in defining CLABSIs. The definition of CLABSI is continuously being updated to improve the misclassification bias inherent in defining CLABSI. This is especially relevant given the stress placed on decreasing health-care-associated infections and the negative consequences associated if unsuccessful. In order to prevent CLABSIs, pediatric and neonatal intensive care units have formed bundles of basic evidenced-based strategies leading to effective reduction of CLABSIs. These basic bundles have been modified for spread to other nonintensive care areas, also yielding great results. However, additional therapies above the basic bundle have yielded mixed results, and more research is needed to understand the cost effectiveness of these therapies in the setting of decreasing CLABSI rates. As a goal, a "getting to zero" CLABSI rate should be set, but it may not be possible without significant resource allocation. PMID:23588892

  4. Reducing uncertainty in managing respiratory tract infections in primary care

    PubMed Central

    Stanton, Naomi; Francis, Nick A; Butler, Chris C

    2010-01-01

    Respiratory tract infections (RTIs) remain the commonest reason for acute consultations in primary care in resource-rich countries. Their spectrum and severity has changed from the time that antibiotics were discovered, largely from improvements in the socioeconomic determinants of health as well as vaccination. The benefits from antibiotic treatment for common RTIs have been shown to be largely overstated. Nevertheless, serious infections do occur. Currently, no clinical features or diagnostic test, alone or in combination, adequately determine diagnosis, aetiology, prognosis, or response to treatment. This narrative review focuses on emerging evidence aimed at helping clinicians reduce and manage uncertainty in treating RTIs. Consultation rate and prescribing rate trends are described, evidence of increasing rates of complications are discussed, and studies and the association with antibiotic prescribing are examined. Methods of improving diagnosis and identifying those patients who are at increased risk of complications from RTIs, using clinical scoring systems, biomarkers, and point of care tests are also discussed. The evidence for alternative management options for RTIs are summarised and the methods for changing public and clinicians' beliefs about antibiotics, including ways in which we can improve clinician–patient communication skills for management of RTIs, are described. PMID:21144191

  5. Herpes simplex virus virion host shutoff (vhs) activity alters periocular disease in mice.

    PubMed

    Smith, T J; Ackland-Berglund, C E; Leib, D A

    2000-04-01

    During lytic infection, the virion host shutoff (vhs) protein of herpes simplex virus (HSV) mediates the rapid degradation of RNA and shutoff of host protein synthesis. In mice, HSV type 1 (HSV-1) mutants lacking vhs activity are profoundly attenuated. HSV-2 has significantly higher vhs activity than HSV-1, eliciting a faster and more complete shutoff. To examine further the role of vhs activity in pathogenesis, we generated an intertypic recombinant virus (KOSV2) in which the vhs open reading frame of HSV-1 strain KOS was replaced with that of HSV-2 strain 333. KOSV2 and a marker-rescued virus, KOSV2R, were characterized in cell culture and tested in an in vivo mouse eye model of latency and pathogenesis. The RNA degradation kinetics of KOSV2 was identical to that of HSV-2 333, and both showed vhs activity significantly higher than that of KOS. This demonstrated that the fast vhs-mediated degradation phenotype of 333 had been conferred upon KOS. The growth of KOSV2 was comparable to that of KOS, 333, and KOSV2R in cell culture, murine corneas, and trigeminal ganglia and had a reactivation frequency similar to those of KOS and KOSV2R from explanted latently infected trigeminal ganglia. There was, however, significantly reduced blepharitis and viral replication within the periocular skin of KOSV2-infected mice compared to mice infected with either KOS or KOSV2R. Taken together, these data demonstrate that heightened vhs activity, in the context of HSV-1 infection, leads to increased viral clearance from the skin of mice and that the replication of virus in the skin is a determining factor for blepharitis. These data also suggest a role for vhs in modulating host responses to HSV infection.

  6. A complex of seven vaccinia virus proteins conserved in all chordopoxviruses is required for the association of membranes and viroplasm to form immature virions

    SciTech Connect

    Szajner, Patricia; Jaffe, Howard; Moss, Bernard . E-mail: bmoss@nih.gov

    2004-12-20

    Early events in vaccinia virus (VAC) morphogenesis, particularly the formation of viral membranes and their association with viroplasm, are poorly understood. Recently, we showed that repression of A30 or G7 expression results in the accumulation of normal viral membranes that form empty-looking immature virions (IV), which are separated from large masses of electron-dense viroplasm. In addition, A30 and G7 physically and functionally interact with each other and with the F10 protein kinase. To identify other proteins involved in early morphogenesis, proteins from cells that had been infected with vaccinia virus expressing an epitope-tagged copy of F10 were purified by immunoaffinity chromatography and analyzed by gel electrophoresis. In addition to F10, A30, and G7, viral proteins A15, D2, D3, and J1 were identified by mass spectrometry of tryptic peptides. Further evidence for the complex was obtained by immunopurification of proteins associated with epitope-tagged A15, D2, and D3. The previously unstudied A15, like other proteins in the complex, was expressed late in infection, associated with virus cores, and required for the stability and kinase activity of F10. Biochemical and electron microscopic analyses indicated that mutants in which A15 or D2 expression was regulated by the Escherichia coli lac operator system exhibited phenotypes characterized by the presence of large numbers of empty immature virions, similar to the results obtained with inducible A30 and G7 mutants. Empty immature virions were also seen by electron microscopy of cells infected with temperature-sensitive mutants of D2 or D3, though the numbers of membrane forms were reduced perhaps due to additional effects of high temperature.

  7. Retroviral proteases and their roles in virion maturation.

    PubMed

    Konvalinka, Jan; Kräusslich, Hans-Georg; Müller, Barbara

    2015-05-01

    Proteolytic processing of viral polyproteins is essential for retrovirus infectivity. Retroviral proteases (PR) become activated during or after assembly of the immature, non-infectious virion. They cleave viral polyproteins at specific sites, inducing major structural rearrangements termed maturation. Maturation converts retroviral enzymes into their functional form, transforms the immature shell into a metastable state primed for early replication events, and enhances viral entry competence. Not only cleavage at all PR recognition sites, but also an ordered sequence of cleavages is crucial. Proteolysis is tightly regulated, but the triggering mechanisms and kinetics and pathway of morphological transitions remain enigmatic. Here, we outline PR structures and substrate specificities focusing on HIV PR as a therapeutic target. We discuss design and clinical success of HIV PR inhibitors, as well as resistance development towards these drugs. Finally, we summarize data elucidating the role of proteolysis in maturation and highlight unsolved questions regarding retroviral maturation.

  8. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses

    PubMed Central

    McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T.; Dennison, S. Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S. Munir; Haynes, Barton F.; Tomaras, Georgia D.

    2016-01-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  9. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses.

    PubMed

    Tay, Matthew Zirui; Liu, Pinghuang; Williams, LaTonya D; McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T; Dennison, S Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S Munir; Moody, M Anthony; Hope, Thomas J; Haynes, Barton F; Tomaras, Georgia D

    2016-08-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  10. Removal of N-linked carbohydrates decreases the infectivity of herpes simplex virus type 1.

    PubMed

    Kühn, J E; Eing, B R; Brossmer, R; Munk, K; Braun, R W

    1988-11-01

    Purified preparations of herpes simplex virus type 1 Angelotti were digested with the exoglycosidases sialidase, beta-galactosidase, N-acetyl-beta-D-glucosaminidase and alpha-mannosidase, and with the endoglycosidases Endo-H and Endo-F. It was found that treatment of virions with Endo-F specifically decreased viral infectivity by a factor of 10. This reduction in titre was not associated with any measurable differences in virus adsorption, suggesting a role of N-linked complex type oligosaccharide chains in penetration. In contrast, a reduction in titre observed upon digestion of virions with exoglycosidases could be attributed to a proteolytic contamination in these enzyme preparations. Treatment of virions with Endo-H, demonstrated to be free of proteolytic contamination, did not reduce viral infectivity. Analysis of endoglycosidase-digested virions by monospecific antibodies and immunoblotting revealed a susceptibility of all four major glycoproteins (gC, gB, gE and gD) to Endo-F, but only gB was susceptible to Endo-H treatment. In contrast, of all the exoglycosidases used only sialidase was found to be active towards native viral glycoproteins. Upon analysis of endoglycosidase-digested virions we could not find any evidence for proteolysis, degradation or altered protein composition of viral envelopes. In contrast, vigorous inhibition of glycoprotein glycosylation by tunicamycin led to the formation of physically intact virions almost completely lacking all major glycoproteins. These data show that digestion of intact virions with glycosidases allows an analysis of the functional relevance of carbohydrate residues without any obvious alterations in the virion glycoprotein composition.

  11. Phosphorylation of Bovine Herpesvirus 1 VP8 Plays a Role in Viral DNA Encapsidation and Is Essential for Its Cytoplasmic Localization and Optimal Virion Incorporation

    PubMed Central

    Zhang, Kuan; Brownlie, Robert; Snider, Marlene

    2016-01-01

    alphaherpesviruses. Interestingly, lack of phosphorylation of VP8 by CK2 and US3 resulted in reduced incorporation of viral DNA into capsids during mutant BoHV-1 infection, as well as lower numbers of extracellular virions. Furthermore, mutant VP8 remained nuclear throughout infection, in contrast to WT VP8, which is nuclear at early stages and Golgi apparatus associated late during infection. This correlates with smaller amounts of mutant VP8 in virions and suggests for the first time that VP8 may be assembled into the virions at two stages, with the latter dependent on phosphorylation. PMID:26889039

  12. Human Immunodeficiency Virus Type 1 Nef protein modulates the lipid composition of virions and host cell membrane microdomains

    PubMed Central

    Brügger, Britta; Krautkrämer, Ellen; Tibroni, Nadine; Munte, Claudia E; Rauch, Susanne; Leibrecht, Iris; Glass, Bärbel; Breuer, Sebastian; Geyer, Matthias; Kräusslich, Hans-Georg; Kalbitzer, Hans Robert; Wieland, Felix T; Fackler, Oliver T

    2007-01-01

    Background The Nef protein of Human Immunodeficiency Viruses optimizes viral spread in the infected host by manipulating cellular transport and signal transduction machineries. Nef also boosts the infectivity of HIV particles by an unknown mechanism. Recent studies suggested a correlation between the association of Nef with lipid raft microdomains and its positive effects on virion infectivity. Furthermore, the lipidome analysis of HIV-1 particles revealed a marked enrichment of classical raft lipids and thus identified HIV-1 virions as an example for naturally occurring membrane microdomains. Since Nef modulates the protein composition and function of membrane microdomains we tested here if Nef also has the propensity to alter microdomain lipid composition. Results Quantitative mass spectrometric lipidome analysis of highly purified HIV-1 particles revealed that the presence of Nef during virus production from T lymphocytes enforced their raft character via a significant reduction of polyunsaturated phosphatidylcholine species and a specific enrichment of sphingomyelin. In contrast, Nef did not significantly affect virion levels of phosphoglycerolipids or cholesterol. The observed alterations in virion lipid composition were insufficient to mediate Nef's effect on particle infectivity and Nef augmented virion infectivity independently of whether virus entry was targeted to or excluded from membrane microdomains. However, altered lipid compositions similar to those observed in virions were also detected in detergent-resistant membrane preparations of virus producing cells. Conclusion Nef alters not only the proteome but also the lipid composition of host cell microdomains. This novel activity represents a previously unrecognized mechanism by which Nef could manipulate HIV-1 target cells to facilitate virus propagation in vivo. PMID:17908312

  13. Hepatitis C Virus Envelope Glycoprotein E1 Forms Trimers at the Surface of the Virion

    PubMed Central

    Falson, Pierre; Bartosch, Birke; Alsaleh, Khaled; Tews, Birke Andrea; Loquet, Antoine; Ciczora, Yann; Riva, Laura; Montigny, Cédric; Montpellier, Claire; Duverlie, Gilles; Pécheur, Eve-Isabelle; le Maire, Marc; Cosset, François-Loïc

    2015-01-01

    ABSTRACT In hepatitis C virus (HCV)-infected cells, the envelope glycoproteins E1 and E2 assemble as a heterodimer. To investigate potential changes in the oligomerization of virion-associated envelope proteins, we performed SDS-PAGE under reducing conditions but without thermal denaturation. This revealed the presence of SDS-resistant trimers of E1 in the context of cell-cultured HCV (HCVcc) as well as in the context of HCV pseudoparticles (HCVpp). The formation of E1 trimers was found to depend on the coexpression of E2. To further understand the origin of E1 trimer formation, we coexpressed in bacteria the transmembrane (TM) domains of E1 (TME1) and E2 (TME2) fused to reporter proteins and analyzed the fusion proteins by SDS-PAGE and Western blotting. As expected for strongly interacting TM domains, TME1–TME2 heterodimers resistant to SDS were observed. These analyses also revealed homodimers and homotrimers of TME1, indicating that such complexes are stable species. The N-terminal segment of TME1 exhibits a highly conserved GxxxG sequence, a motif that is well documented to be involved in intramembrane protein-protein interactions. Single or double mutations of the glycine residues (Gly354 and Gly358) in this motif markedly decreased or abrogated the formation of TME1 homotrimers in bacteria, as well as homotrimers of E1 in both HCVpp and HCVcc systems. A concomitant loss of infectivity was observed, indicating that the trimeric form of E1 is essential for virus infectivity. Taken together, these results indicate that E1E2 heterodimers form trimers on HCV particles, and they support the hypothesis that E1 could be a fusion protein. IMPORTANCE HCV glycoproteins E1 and E2 play an essential role in virus entry into liver cells as well as in virion morphogenesis. In infected cells, these two proteins form a complex in which E2 interacts with cellular receptors, whereas the function of E1 remains poorly understood. However, recent structural data suggest that E1

  14. Antiretroviral therapy reduces neurodegeneration in human immunodeficiency virus infection

    PubMed Central

    Bryant, Alex K.; Ellis, Ronald J.; Umlauf, Anya; Gouaux, Ben; Soontornniyomkij, Virawudh; Letendre, Scott L.; Achim, Cristian L.; Masliah, Eliezer; Grant, Igor; Moore, David J.

    2015-01-01

    Objective To determine the effect of virally-suppressive antiretroviral therapy on cortical neurodegeneration and associated neurocognitive impairment. Design Retrospective, postmortem observational study. Methods Clinical neuropsychological and postmortem neuropathology data were analyzed in 90 human immunodeficiency virus-infected volunteers from the general community who had never undergone antiretroviral therapy (n=7, “naïve”) or who had undergone antiretroviral therapy and whose plasma viral load was detectable (n = 64 “unsuppressed”) or undetectable (n = 19, “suppressed”) at the last clinical visit prior to death. Subjects were predominately male (74/90, 82%) with a mean age of 44.7 years (SD 9.8). Cortical neurodegeneration was quantified by measuring microtubule-associated protein (MAP2) and synaptophysin (SYP) density in midfrontal cortex tissue sections. Results The suppressed group had higher SYP density than the naïve group (p = 0.007) and higher MAP2 density than the unsuppressed group (p = 0.04). The suppressed group had lower odds of human immunodeficiency virus-associated neurocognitive disorders than naïve (OR 0.07, p = 0.03). Higher SYP was associated with lower likelihood of human immunodeficiency virus-associated neurocognitive disorders in univariable (OR 0.8, p=0.03) and multivariable models after controlling for antiretroviral treatment and brain human immunodeficiency virus p24 protein levels (OR 0.72, p=0.01). Conclusions We conclude that virally suppressive antiretroviral treatment protects against cortical neurodegeneration. Further, we find evidence supporting the causal chain from treatment-mediated peripheral and central nervous system viral load suppression to reduced neurodegeneration and improved neurocognitive outcomes. PMID:25686681

  15. Target-dependent enrichment of virions determines the reduction of high-throughput sequencing in virus discovery.

    PubMed

    Jensen, Randi Holm; Mollerup, Sarah; Mourier, Tobias; Hansen, Thomas Arn; Fridholm, Helena; Nielsen, Lars Peter; Willerslev, Eske; Hansen, Anders Johannes; Vinner, Lasse

    2015-01-01

    Viral infections cause many different diseases stemming both from well-characterized viral pathogens but also from emerging viruses, and the search for novel viruses continues to be of great importance. High-throughput sequencing is an important technology for this purpose. However, viral nucleic acids often constitute a minute proportion of the total genetic material in a sample from infected tissue. Techniques to enrich viral targets in high-throughput sequencing have been reported, but the sensitivity of such methods is not well established. This study compares different library preparation techniques targeting both DNA and RNA with and without virion enrichment. By optimizing the selection of intact virus particles, both by physical and enzymatic approaches, we assessed the effectiveness of the specific enrichment of viral sequences as compared to non-enriched sample preparations by selectively looking for and counting read sequences obtained from shotgun sequencing. Using shotgun sequencing of total DNA or RNA, viral targets were detected at concentrations corresponding to the predicted level, providing a foundation for estimating the effectiveness of virion enrichment. Virion enrichment typically produced a 1000-fold increase in the proportion of DNA virus sequences. For RNA virions the gain was less pronounced with a maximum 13-fold increase. This enrichment varied between the different sample concentrations, with no clear trend. Despite that less sequencing was required to identify target sequences, it was not evident from our data that a lower detection level was achieved by virion enrichment compared to shotgun sequencing.

  16. The ns12.9 Accessory Protein of Human Coronavirus OC43 Is a Viroporin Involved in Virion Morphogenesis and Pathogenesis

    PubMed Central

    Zhang, Ronghua; Wang, Kai; Ping, Xianqiang; Yu, Wenjing

    2015-01-01

    ABSTRACT An accessory gene between the S and E gene loci is contained in all coronaviruses (CoVs), and its function has been studied in some coronaviruses. This gene locus in human coronavirus OC43 (HCoV-OC43) encodes the ns12.9 accessory protein; however, its function during viral infection remains unknown. Here, we engineered a recombinant mutant virus lacking the ns12.9 protein (HCoV-OC43-Δns12.9) to characterize the contributions of ns12.9 in HCoV-OC43 replication. The ns12.9 accessory protein is a transmembrane protein and forms ion channels in both Xenopus oocytes and yeast through homo-oligomerization, suggesting that ns12.9 is a newly recognized viroporin. HCoV-OC43-Δns12.9 presented at least 10-fold reduction of viral titer in vitro and in vivo. Intriguingly, exogenous ns12.9 and heterologous viroporins with ion channel activity could compensate for the production of HCoV-OC43-Δns12.9, indicating that the ion channel activity of ns12.9 plays a significant role in the production of infectious virions. Systematic dissection of single-cycle replication revealed that ns12.9 protein had no measurable effect on virus entry, subgenomic mRNA (sgmRNA) synthesis, and protein expression. Further characterization revealed that HCoV-OC43-Δns12.9 was less efficient in virion morphogenesis than recombinant wild-type virus (HCoV-OC43-WT). Moreover, reduced viral replication, inflammatory response, and virulence in HCoV-OC43-Δns12.9-infected mice were observed compared to the levels for HCoV-OC43-WT-infected mice. Taken together, our results demonstrated that the ns12.9 accessory protein functions as a viroporin and is involved in virion morphogenesis and the pathogenesis of HCoV-OC43 infection. IMPORTANCE HCoV-OC43 was isolated in the 1960s and is a major agent of the common cold. The functions of HCoV-OC43 structural proteins have been well studied, but few studies have focused on its accessory proteins. In the present study, we demonstrated that the ns12.9 protein

  17. Characterization of the Determinants of NS2-3-Independent Virion Morphogenesis of Pestiviruses

    PubMed Central

    Klemens, O.; Dubrau, D.

    2015-01-01

    diarrhea virus, nonstructural protein NS2-3 is of critical importance to switch between these processes. While free NS3 is essential for RNA replication, uncleaved NS2-3, which accumulates over time in the infected cell, is required for virion morphogenesis. In contrast, the virion morphogenesis of the related hepatitis C virus is independent from uncleaved NS2-NS3. Here, we demonstrate that pestiviruses can adapt to virion morphogenesis in the absence of uncleaved NS2-3 by just two amino acid exchanges. While the mechanism behind this gain of function remains elusive, the fact that it can be achieved by such minor changes is in line with the assumption that an ancestral virus already used this mechanism but lost it in the course of adapting to a new host/infection strategy. PMID:26355097

  18. Quercetin reduces susceptibility to influenza infection following stressful exercise.

    PubMed

    Davis, J M; Murphy, E A; McClellan, J L; Carmichael, M D; Gangemi, J D

    2008-08-01

    Exercise stress is associated with increased risk for upper respiratory tract infection. We have shown that exercise stress can increase susceptibility to infection. Quercetin, a flavonoid present in a wide variety of fruits and vegetables, has been reported to inhibit infectivity and replication of a broad spectrum of viruses and may offset the increase in susceptibility to infection associated with stressful exercise. This study examined the effects of quercetin feedings on susceptibility to the influenza virus A/Puerto Rico/8/34 (H1N1) following stressful exercise. Mice were randomly assigned to one of four treatment groups: exercise-placebo, exercise-quercetin, control-placebo, or control-quercetin. Exercise consisted of a run to fatigue (approximately 140 min) on a treadmill for 3 consecutive days. Quercetin (12.5 mg/kg) was administered via gavage for 7 days before viral challenge. At 30 min after the last bout of exercise or rest, mice (n=23-30) were intranasally inoculated with a standardized dose of influenza virus (0.04 hemagglutinating units). Mice were monitored daily for morbidity (time to sickness), symptom severity, and mortality (time to death) for 21 days. Exercise stress was associated with an increased susceptibility to infection [morbidity, mortality, and symptom severity on days 5-7 (P<0.05)]; quercetin offset the increase in susceptibility to infection [morbidity, mortality, and symptom severity on days 5-7 (P<0.05)] that was associated with stressful exercise. These data suggest that short-term quercetin feedings may prove to be an effective strategy to lessen the impact of stressful exercise on susceptibility to respiratory infection.

  19. Virion stability is important for the circulative transmission of tomato yellow leaf curl sardinia virus by Bemisia tabaci, but virion access to salivary glands does not guarantee transmissibility.

    PubMed

    Caciagli, Piero; Medina Piles, Vicente; Marian, Daniele; Vecchiati, Manuela; Masenga, Vera; Mason, Giovanna; Falcioni, Tania; Noris, Emanuela

    2009-06-01

    The capsid protein (CP) of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV), family Geminiviridae, is indispensable for plant infection and vector transmission. A region between amino acids 129 and 152 is critical for virion assembly and insect transmissibility. Two previously described mutants, one with a double Q129P Q134H mutation (PNHD) and another with a further D152E change (PNHE), were found nontransmissible (NT). Another NT mutant with a single N130D change (QDQD) was retrieved from a new mutational analysis. In this study, these three NT mutants and the wild-type (wt) virus were compared in their relationships with the whitefly vector Bemisia tabaci and the nonvector Trialeurodes vaporariorum. Retention kinetics of NT mutants were analyzed by quantitative dot blot hybridization in whiteflies fed on infected plants. The QDQD mutant, whose virions appeared nongeminate following purification, was hardly detectable in either whitefly species at any sampling time. The PNHD mutant was acquired and circulated in both whitefly species for up to 10 days, like the wt virus, while PNHE circulated in B. tabaci only. Using immunogold labeling, both PNHD and PNHE CPs were detected in B. tabaci salivary glands (SGs) like the wt virus, while no labeling was found in any whitefly tissue with the QDQD mutant. Significant inhibition of transmission of the wt virus was observed after prior feeding of the insects on plants infected with the PNHE mutant, but not on plants infected with the other mutants. Virion stability and ability to cross the SG barrier are necessary for TYLCSV transmission, but interactions with molecular components inside the SGs are also critical for transmissibility.

  20. UV-Sensitivity of Shiga Toxin-Converting Bacteriophage Virions Φ24B, 933W, P22, P27 and P32.

    PubMed

    Bloch, Sylwia; Nejman-Faleńczyk, Bożena; Topka, Gracja; Dydecka, Aleksandra; Licznerska, Katarzyna; Narajczyk, Magdalena; Necel, Agnieszka; Węgrzyn, Alicja; Węgrzyn, Grzegorz

    2015-09-01

    Shiga toxin-converting bacteriophages (Stx phages) are present as prophages in Shiga toxin-producing Escherichia coli (STEC) strains. Theses phages can be transmitted to previously non-pathogenic E. coli cells making them potential producers of Shiga toxins, as they bear genes for these toxins in their genomes. Therefore, sensitivity of Stx phage virions to various conditions is important in both natural processes of spreading of these viruses and potential prophylactic control of appearance of novel pathogenic E. coli strains. In this report we provide evidence that virions of Stx phages are significantly more sensitive to UV irradiation than bacteriophage λ. Following UV irradiation of Stx virions at the dose of 50 J/m², their infectivity dropped by 1-3 log10, depending on the kind of phage. Under these conditions, a considerable release of phage DNA from virions was observed, and electron microscopy analyses indicated a large proportion of partially damaged virions. Infection of E. coli cells with UV-irradiated Stx phages resulted in significantly decreased levels of expression of N and cro genes, crucial for lytic development. We conclude that inactivation of Stx virions caused by relatively low dose of UV light is due to damage of capsids that prevents effective infection of the host cells.

  1. UV-Sensitivity of Shiga Toxin-Converting Bacteriophage Virions Φ24B, 933W, P22, P27 and P32

    PubMed Central

    Bloch, Sylwia; Nejman-Faleńczyk, Bożena; Topka, Gracja; Dydecka, Aleksandra; Licznerska, Katarzyna; Narajczyk, Magdalena; Necel, Agnieszka; Węgrzyn, Alicja; Węgrzyn, Grzegorz

    2015-01-01

    Shiga toxin-converting bacteriophages (Stx phages) are present as prophages in Shiga toxin-producing Escherichia coli (STEC) strains. Theses phages can be transmitted to previously non-pathogenic E. coli cells making them potential producers of Shiga toxins, as they bear genes for these toxins in their genomes. Therefore, sensitivity of Stx phage virions to various conditions is important in both natural processes of spreading of these viruses and potential prophylactic control of appearance of novel pathogenic E. coli strains. In this report we provide evidence that virions of Stx phages are significantly more sensitive to UV irradiation than bacteriophage λ. Following UV irradiation of Stx virions at the dose of 50 J/m2, their infectivity dropped by 1–3 log10, depending on the kind of phage. Under these conditions, a considerable release of phage DNA from virions was observed, and electron microscopy analyses indicated a large proportion of partially damaged virions. Infection of E. coli cells with UV-irradiated Stx phages resulted in significantly decreased levels of expression of N and cro genes, crucial for lytic development. We conclude that inactivation of Stx virions caused by relatively low dose of UV light is due to damage of capsids that prevents effective infection of the host cells. PMID:26402701

  2. Pathogenesis of herpes simplex virus type 2 virion host shutoff (vhs) mutants.

    PubMed

    Smith, Tracy J; Morrison, Lynda A; Leib, David A

    2002-03-01

    During lytic infection, the virion host shutoff (vhs) protein mediates the rapid degradation of mRNA and the shutoff of host protein synthesis. In vivo, herpes simplex virus type 1 (HSV-1) mutants lacking vhs activity are profoundly attenuated. Homologs of vhs exist in all of the neurotropic herpesviruses, and the goal of this study was to determine the virulence of HSV-2 mutants lacking vhs. Two HSV-2 recombinants were used in this study: 333-vhsB, which has a lacZ cassette inserted into the N terminus of vhs, and 333d41, which has a 939-bp deletion in vhs. As expected, both 333-vhsB and 333d41 failed to induce the cellular RNA degradation characteristic of HSV. Corneal, vaginal, and intracerebral routes of infection were used to study pathogenesis. Both viruses grew to significantly lower titers in the corneas, trigeminal ganglia, vaginas, dorsal root ganglia, spinal cords, and brains of mice than wild-type and rescue viruses, with a correspondingly reduced induction of disease. Both viruses, however, reactivated efficiently from explanted trigeminal ganglia, showing that vhs is dispensable for reactivation. The lethality of 333d41 following peripheral infection of mice, however, was significantly higher than that of 333-vhsB, suggesting that some of the attenuation of 333-vhsB may be due to the presence of a lacZ cassette in the vhs locus. Taken together, these data show that vhs represents an important determinant of HSV-2 pathogenesis and have implications for the design of HSV-2 recombinants and vaccines.

  3. From Crescent to Mature Virion: Vaccinia Virus Assembly and Maturation

    PubMed Central

    Liu, Liang; Cooper, Tamara; Howley, Paul M.; Hayball, John D.

    2014-01-01

    Vaccinia virus (VACV) has achieved unprecedented success as a live viral vaccine for smallpox which mitigated eradication of the disease. Vaccinia virus has a complex virion morphology and recent advances have been made to answer some of the key outstanding questions, in particular, the origin and biogenesis of the virion membrane, the transformation from immature virion (IV) to mature virus (MV), and the role of several novel genes, which were previously uncharacterized, but have now been shown to be essential for VACV virion formation. This new knowledge will undoubtedly contribute to the rational design of safe, immunogenic vaccine candidates, or effective antivirals in the future. This review endeavors to provide an update on our current knowledge of the VACV maturation processes with a specific focus on the initiation of VACV replication through to the formation of mature virions. PMID:25296112

  4. Bacteriophage virion-associated peptidoglycan hydrolases: potential new enzybiotics.

    PubMed

    Rodríguez-Rubio, Lorena; Martínez, Beatriz; Donovan, David M; Rodríguez, Ana; García, Pilar

    2013-11-01

    Virion-associated peptidoglycan hydrolases (VAPGH) are phage-encoded lytic enzymes that locally degrade the peptidoglycan (PG) of the bacterial cell wall during infection. In contrast to endolysins, PGHs that mediate lysis of the host bacteria at the end of the lytic cycle to release of phage progeny, the action of VAPGHs generates a small hole through which the phage tail tube crosses the cell envelope to eject the phage genetic material at the beginning to the infection cycle. The antimicrobial activity of VAPGHs was first discovered through the observation of the phenomenon of 'lysis from without', in which the disruption of the bacterial cell wall occurs prior to phage production and is caused by a high number of phages adsorbed onto the cell surface. Based on a unique combination of properties of VAPGHs such as high specificity, remarkable thermostability, and a modular organization, these proteins are potential candidates as new antibacterial agents, e.g. against antibiotic-resistant bacteria in human therapy and veterinary as well as biopreservatives in food safety, and as biocontrol agents of harmful bacteria in agriculture. This review provides an overview of the different VAPGHs discovered to date and their potential as novel antimicrobials.

  5. Adenovirus L1 52- and 55-kilodalton proteins are required for assembly of virions.

    PubMed Central

    Hasson, T B; Soloway, P D; Ornelles, D A; Doerfler, W; Shenk, T

    1989-01-01

    A variant of adenovirus type 5 that contained a mutation within the L1 52- and 55-kilodalton (52/55K) protein-coding region was isolated. The mutant, termed ts369, produced L1 52/55K proteins with a two-amino-acid substitution and was temperature sensitive. Temperature-shift experiments indicated that the ts369 defect was late in the viral growth cycle. DNA replication and synthesis of late proteins occurred normally in ts369-infected cells at the nonpermissive temperature, but mature virions were not produced. Rather, capsidlike particles associated with the left-terminal region of the viral chromosome accumulated. These incomplete particles could not be chased into mature virions when the infected cells were shifted to the permissive temperature. However, previously synthesized proteins could be assembled into virions in the presence of a protein synthesis inhibitor upon shiftdown from the nonpermissive temperature, suggesting that the inactivation of the L1 52/55K proteins was reversible. These results indicate that the adenovirus L1 52/55K proteins play a role in the assembly of infectious virus particles. Images PMID:2760976

  6. Virion Glycoprotein-Mediated Immune Evasion by Human Cytomegalovirus: a Sticky Virus Makes a Slick Getaway.

    PubMed

    Gardner, Thomas J; Tortorella, Domenico

    2016-09-01

    The prototypic herpesvirus human cytomegalovirus (CMV) exhibits the extraordinary ability to establish latency and maintain a chronic infection throughout the life of its human host. This is even more remarkable considering the robust adaptive immune response elicited by infection and reactivation from latency. In addition to the ability of CMV to exist in a quiescent latent state, its persistence is enabled by a large repertoire of viral proteins that subvert immune defense mechanisms, such as NK cell activation and major histocompatibility complex antigen presentation, within the cell. However, dissemination outside the cell presents a unique existential challenge to the CMV virion, which is studded with antigenic glycoprotein complexes targeted by a potent neutralizing antibody response. The CMV virion envelope proteins, which are critical mediators of cell attachment and entry, possess various characteristics that can mitigate the humoral immune response and prevent viral clearance. Here we review the CMV glycoprotein complexes crucial for cell attachment and entry and propose inherent properties of these proteins involved in evading the CMV humoral immune response. These include viral glycoprotein polymorphism, epitope competition, Fc receptor-mediated endocytosis, glycan shielding, and cell-to-cell spread. The consequences of CMV virion glycoprotein-mediated immune evasion have a major impact on persistence of the virus in the population, and a comprehensive understanding of these evasion strategies will assist in designing effective CMV biologics and vaccines to limit CMV-associated disease. PMID:27307580

  7. The papillomavirus virion: a machine built to hide molecular Achilles' heels.

    PubMed

    Buck, Christopher B; Trus, Benes L

    2012-01-01

    Papillomaviruses are a diverse group of DNA viruses that infect the skin and mucosal tissues of vertebrates. More than 100 distinct human papillomavirus (HPV) genotypes have so far been identified. A subset of HPVs is known to cause human cancer. Although recently developed vaccines protect vaccinated individuals from the two most carcinogenic HPV types, there is a pressing need for next-generation vaccines that might offer broad-spectrum protection against the full range of cancer-causing HPVs. The ongoing development of such vaccines will be facilitated by a deeper understanding of the mechanics of the assembly of the nonenveloped papillomavirus virion, as well as the machine-like structural changes that occur in the virion during the process of infectious entry into host cells. This chapter reviews the field's current knowledge of these two aspects of papillomavirus biology and speculates about areas where further work is needed.

  8. Virion Structure of Israeli Acute Bee Paralysis Virus

    PubMed Central

    Mullapudi, Edukondalu; Přidal, Antonín; Pálková, Lenka; de Miranda, Joachim R.

    2016-01-01

    ABSTRACT The pollination services provided by the western honeybee (Apis mellifera) are critical for agricultural production and the diversity of wild flowering plants. However, honeybees suffer from environmental pollution, habitat loss, and pathogens, including viruses that can cause fatal diseases. Israeli acute bee paralysis virus (IAPV), from the family Dicistroviridae, has been shown to cause colony collapse disorder in the United States. Here, we present the IAPV virion structure determined to a resolution of 4.0 Å and the structure of a pentamer of capsid protein protomers at a resolution of 2.7 Å. IAPV has major capsid proteins VP1 and VP3 with noncanonical jellyroll β-barrel folds composed of only seven instead of eight β-strands, as is the rule for proteins of other viruses with the same fold. The maturation of dicistroviruses is connected to the cleavage of precursor capsid protein VP0 into subunits VP3 and VP4. We show that a putative catalytic site formed by the residues Asp-Asp-Phe of VP1 is optimally positioned to perform the cleavage. Furthermore, unlike many picornaviruses, IAPV does not contain a hydrophobic pocket in capsid protein VP1 that could be targeted by capsid-binding antiviral compounds. IMPORTANCE Honeybee pollination is required for agricultural production and to sustain the biodiversity of wild flora. However, honeybee populations in Europe and North America are under pressure from pathogens, including viruses that cause colony losses. Viruses from the family Dicistroviridae can cause honeybee infections that are lethal, not only to individual honeybees, but to whole colonies. Here, we present the virion structure of an Aparavirus, Israeli acute bee paralysis virus (IAPV), a member of a complex of closely related viruses that are distributed worldwide. IAPV exhibits unique structural features not observed in other picorna-like viruses. Capsid protein VP1 of IAPV does not contain a hydrophobic pocket, implying that capsid

  9. Herpes simplex virus 1 Us3 deletion mutant is infective despite impaired capsid translocation to the cytoplasm.

    PubMed

    Wild, Peter; Leisinger, Sabine; de Oliveira, Anna Paula; Schraner, Elisabeth M; Kaech, Andres; Ackermann, Mathias; Tobler, Kurt

    2015-01-12

    Herpes simplex virus 1 (HSV-1) capsids are assembled in the nucleus bud at the inner nuclear membrane into the perinuclear space, acquiring envelope and tegument. In theory, these virions are de-enveloped by fusion of the envelope with the outer nuclear membrane and re-enveloped by Golgi membranes to become infective. Us3 enables the nucleus to cytoplasm capsid translocation. Nevertheless, Us3 is not essential for the production of infective progeny viruses. Determination of phenotype distribution by quantitative electron microscopy, and calculation per mean nuclear or cell volume revealed the following: (i) The number of R7041(∆US3) capsids budding at the inner nuclear membrane was significantly higher than that of wild type HSV-1; (ii) The mean number of R7041(∆US3) virions per mean cell volume was 2726, that of HSV-1 virions 1460 by 24 h post inoculation; (iii) 98% of R7041(∆US3) virions were in the perinuclear space; (iv) The number of R7041(∆US3) capsids in the cytoplasm, including those budding at Golgi membranes, was significantly reduced. Cell associated R7041(∆US3) yields were 2.37×10(8) and HSV-1 yields 1.57×10(8) PFU/mL by 24 h post inoculation. We thus conclude that R7041(∆US3) virions, which acquire envelope and tegument by budding at the inner nuclear membrane into the perinuclear space, are infective.

  10. Herpes Simplex Virus 1 Us3 Deletion Mutant is Infective Despite Impaired Capsid Translocation to the Cytoplasm

    PubMed Central

    Wild, Peter; Leisinger, Sabine; de Oliveira, Anna Paula; Schraner, Elisabeth M.; Kaech, Andres; Ackermann, Mathias; Tobler, Kurt

    2015-01-01

    Herpes simplex virus 1 (HSV-1) capsids are assembled in the nucleus bud at the inner nuclear membrane into the perinuclear space, acquiring envelope and tegument. In theory, these virions are de-enveloped by fusion of the envelope with the outer nuclear membrane and re-enveloped by Golgi membranes to become infective. Us3 enables the nucleus to cytoplasm capsid translocation. Nevertheless, Us3 is not essential for the production of infective progeny viruses. Determination of phenotype distribution by quantitative electron microscopy, and calculation per mean nuclear or cell volume revealed the following: (i) The number of R7041(∆US3) capsids budding at the inner nuclear membrane was significantly higher than that of wild type HSV-1; (ii) The mean number of R7041(∆US3) virions per mean cell volume was 2726, that of HSV-1 virions 1460 by 24 h post inoculation; (iii) 98% of R7041(∆US3) virions were in the perinuclear space; (iv) The number of R7041(∆US3) capsids in the cytoplasm, including those budding at Golgi membranes, was significantly reduced. Cell associated R7041(∆US3) yields were 2.37 × 108 and HSV-1 yields 1.57 × 108 PFU/mL by 24 h post inoculation. We thus conclude that R7041(∆US3) virions, which acquire envelope and tegument by budding at the inner nuclear membrane into the perinuclear space, are infective. PMID:25588052

  11. Infection of Citrus Roots by Tylenchulus semipenetrans Reduces Root Infection by Phytophthora nicotianae

    PubMed Central

    El-Borai, F. E.; Duncan, L. W.; Graham, J. H.

    2002-01-01

    Bioassays and whole-plant experiments were conducted to investigate the interaction between Tylenchulus semipenetrans and Phytophthora nicotianae. Both organisms are parasites of the citrus fibrous root cortex. Nematode-infected and non-infected root segments were excised from naturally infected field roots and placed on water agar in close proximity to agar plugs of P. nicotianae and then transferred to a Phytophthora-selective medium. At 10 and 12 days, 50% fewer nematode-infected segments were infected by P. nicotianae than non-infected segments. In whole-plant experiments in glass test tubes, sour orange seedlings were inoculated with two densities (8,000 or 80,000 eggs and second-stage juveniles) of T. semipenetrans, and after establishment of infection were inoculated with two densities (9,000 and 90,000 zoospores) of P. nicotianae. In the first experiment, fungal protein was 53% to 65% lower in the roots infected by both organisms than in roots infected by the fungus only. Compared to plants infected only by P. nicotianae, shoot weights were 33% to 50% greater (P ≤ 0.05) in plants infected by both parasites, regardless of inoculum density. Fibrous and tap root weights were 5% to 23% and 19% to 34% greater (P ≤ 0.05), respectively, in nematode-fungus combination treatments compared to the fungus alone. A second experiment was conducted, where plants were infected by the fungus, the nematode, both organisms, or neither organism. The soil mixture pH for 50% of the plants was adjusted from 4.5 to 7.0 to favor nematode infection. A higher rate of nematode infection of plants growing at pH 7.0 compared to pH 4.5 resulted in greater suppression of fungal development and greater inhibition of fungal damage to the plant. Compared to plants infected only by P. nicotianae, shoot and root weights were 37% and 33% greater (P ≤ 0.05), respectively, in plants infected by both parasites. These experiments have revealed antagonism between T. semipenetrans and P

  12. Foodborne disease prevention and broiler chickens with reduced Campylobacter infection.

    PubMed

    Bahrndorff, Simon; Rangstrup-Christensen, Lena; Nordentoft, Steen; Hald, Birthe

    2013-03-01

    Studies have suggested that flies play a linking role in the epidemiology of Campylobacter spp. in broiler chickens and that fly screens can reduce the prevalence of Campylobacter spp. We examined the year-round and long-term effects of fly screens in 10 broiler chicken houses (99 flocks) in Denmark. Prevalence of Campylobacter spp.-positive flocks was significantly reduced, from 41.4% during 2003-2005 (before fly screens) to 10.3% in 2006-2009 (with fly screens). In fly screen houses, Campylobacter spp. prevalence did not peak during the summer. Nationally, prevalence of Campylobacter spp.-positive flocks in Denmark could have been reduced by an estimated 77% during summer had fly screens been part of biosecurity practices. These results imply that fly screens might help reduce prevalence of campylobacteriosis among humans, which is closely linked to Campylobacter spp. prevalence among broiler chicken flocks. PMID:23628089

  13. Foodborne disease prevention and broiler chickens with reduced Campylobacter infection.

    PubMed

    Bahrndorff, Simon; Rangstrup-Christensen, Lena; Nordentoft, Steen; Hald, Birthe

    2013-03-01

    Studies have suggested that flies play a linking role in the epidemiology of Campylobacter spp. in broiler chickens and that fly screens can reduce the prevalence of Campylobacter spp. We examined the year-round and long-term effects of fly screens in 10 broiler chicken houses (99 flocks) in Denmark. Prevalence of Campylobacter spp.-positive flocks was significantly reduced, from 41.4% during 2003-2005 (before fly screens) to 10.3% in 2006-2009 (with fly screens). In fly screen houses, Campylobacter spp. prevalence did not peak during the summer. Nationally, prevalence of Campylobacter spp.-positive flocks in Denmark could have been reduced by an estimated 77% during summer had fly screens been part of biosecurity practices. These results imply that fly screens might help reduce prevalence of campylobacteriosis among humans, which is closely linked to Campylobacter spp. prevalence among broiler chicken flocks.

  14. Soybean Resistance to Cercospora sojina Infection Is Reduced by Silicon.

    PubMed

    Nascimento, Kelly Juliane Telles; Debona, Daniel; França, Sueny Kelly Santos; Gonçalves, Mariana Gabriele Marcolino; DaMatta, Fábio Murilo; Rodrigues, Fabrício Ávila

    2014-11-01

    Frogeye leaf spot, caused by Cercospora sojina, is one of the most important leaf diseases of soybean worldwide. Silicon (Si) is known to increase the resistance of several plant species to pathogens. The cultivars Bossier and Conquista, which are susceptible and resistant, respectively, to frogeye leaf spot, supplied and nonsupplied with Si were examined for the activities of defense enzymes and the concentrations of total soluble phenolics (TSP) and lignin-thioglycolic acid (LTGA) derivatives at 8, 14, and 16 days after inoculation (dai) with C. sojina. The importance of cell wall degrading enzymes (CWDE) to the infection process of C. sojina and the effect of Si on their activities were also determined. Soybean plants were grown in hydroponic culture containing either 0 or 2 mM Si (-Si and +Si, respectively) and noninoculated or C. sojina inoculated. Severity of frogeye leaf spot was higher in cultivar Bossier plants than cultivar Conquista and also in the +Si plants compared with their -Si counterparts. Except for the concentrations of TSP and LTGA derivatives, activities of defense enzymes and the CWDE did not change for +Si noninoculated plants regardless of the cultivar. The activities of lipoxygenases, phenylalanine ammonia-lyases, chitinases, and polyphenoloxidases as well as the activities of CWDE decreased for the +Si inoculated plants. The results from this study demonstrated that defense enzyme activities decreased in soybean plants supplied with Si, which compromised resistance to C. sojina infection.

  15. Reducing catheter-associated urinary tract infections in a neuro-spine intensive care unit.

    PubMed

    Schelling, Kimberly; Palamone, Janet; Thomas, Kathryn; Naidech, Andrew; Silkaitis, Christina; Henry, Jennifer; Bolon, Maureen; Zembower, Teresa R

    2015-08-01

    A collaborative effort reduced catheter-associated urinary tract infections in the neuro-spine intensive care unit where the majority of infections occurred at our institution. Our stepwise approach included retrospective data review, daily rounding with clinicians, developing and implementing an action plan, conducting practice audits, and sharing of real-time data outcomes. The catheter-associated urinary tract infection rate was reduced from 8.18 to 0.93 per 1,000 catheter-days and standardized infection ratio decreased from 2.16 to 0.37.

  16. Cross-dressing the virion: the transcapsidation of adeno-associated virus serotypes functionally defines subgroups.

    PubMed

    Rabinowitz, Joseph E; Bowles, Dawn E; Faust, Susan M; Ledford, Julie G; Cunningham, Scott E; Samulski, R Jude

    2004-05-01

    For all adeno-associated virus (AAV) serotypes, 60 monomers of the Vp1, Vp2, and Vp3 structural proteins assemble via an unknown mechanism to form an intact capsid. In an effort to better understand the properties of the capsid monomers and their role in viral entry and infection, we evaluated whether monomers from distinct serotypes can be mixed to form infectious particles with unique phenotypes. This transcapsidation approach consisted of the transfection of pairwise combinations of AAV serotype 1 to 5 helper plasmids to produce mosaic capsid recombinant AAV (rAAV). All ratios (19:1, 3:1, 1:1, 1:3, and 1:19) of these mixtures were able to replicate the green fluorescent protein transgene and to produce capsid proteins. A high-titer rAAV was obtained with mixtures that included either serotype 1, 2, or 3, whereas an rAAV of intermediate titer was obtained from serotype 5 mixtures. Only mixtures containing the AAV4 capsid exhibited reduced packaging capacity. The binding profiles of the mixed-virus preparations to either heparin sulfate (HS) or mucin agarose revealed that only AAV3-AAV5 mixtures at the 3:1 ratio exhibited duality in binding. All other mixtures displayed either an abrupt shift or a gradual alteration in the binding profile to the respective ligand upon increase of a capsid component that conferred either HS or mucin binding. The transduction of cell lines was used to further evaluate the phenotypes of these transcapsidated virions. Three transduction profiles were observed: (i) small to no change regardless of ratio, (ii) a gradual increase in transduction consistent with titration of a second capsid component, or (iii) an abrupt increase in transduction (threshold effect) dependent on the specific ratios used. Interestingly, an unexpected synergistic effect in transduction was observed when AAV1 helper constructs were combined with type 2 or type 3 recipient helpers. Further studies determined that at least two components contributed to this

  17. A collaborative approach to reduce healthcare-associated infections.

    PubMed

    Su, Guizhen

    Healthcare-associated infections (HAIs) continue to be an ongoing issue for patients in acute hospital settings. Effectively preventing and controlling HAIs requires a collaborative approach compelling all healthcare staff to take up responsibilities and be involved. A surgical ward in an acute hospital aimed to implement comprehensive HAI prevention strategies by applying both Kotter's eight-step change model and the practice development principles into its current system. The project motivated staff to be involved and engaged in the assessment, implementation and evaluation of the project processes, and take ownership of the practice change. It focused on ensuring a clean environment, improving hand hygiene compliance, increasing staff's knowledge base regarding HAIs and enhancing active surveillance. The project achieved success in the reduction and prevention of HAIs as well as the development of a sustainable workplace culture. PMID:27281587

  18. Ebola Virion Attachment and Entry into Human Macrophages Profoundly Effects Early Cellular Gene Expression

    PubMed Central

    Feldmann, Friedericke; Buehler, Lukas K.; Kindrachuk, Jason; DeFilippis, Victor; da Silva Correia, Jean; Früh, Klaus; Kuhn, Jens H.; Burton, Dennis R.; Feldmann, Heinz

    2011-01-01

    Zaire ebolavirus (ZEBOV) infections are associated with high lethality in primates. ZEBOV primarily targets mononuclear phagocytes, which are activated upon infection and secrete mediators believed to trigger initial stages of pathogenesis. The characterization of the responses of target cells to ZEBOV infection may therefore not only further understanding of pathogenesis but also suggest possible points of therapeutic intervention. Gene expression profiles of primary human macrophages exposed to ZEBOV were determined using DNA microarrays and quantitative PCR to gain insight into the cellular response immediately after cell entry. Significant changes in mRNA concentrations encoding for 88 cellular proteins were observed. Most of these proteins have not yet been implicated in ZEBOV infection. Some, however, are inflammatory mediators known to be elevated during the acute phase of disease in the blood of ZEBOV-infected humans. Interestingly, the cellular response occurred within the first hour of Ebola virion exposure, i.e. prior to virus gene expression. This observation supports the hypothesis that virion binding or entry mediated by the spike glycoprotein (GP1,2) is the primary stimulus for an initial response. Indeed, ZEBOV virions, LPS, and virus-like particles consisting of only the ZEBOV matrix protein VP40 and GP1,2 (VLPVP40-GP) triggered comparable responses in macrophages, including pro-inflammatory and pro-apoptotic signals. In contrast, VLPVP40 (particles lacking GP1,2) caused an aberrant response. This suggests that GP1,2 binding to macrophages plays an important role in the immediate cellular response. PMID:22028943

  19. Mapping the Small RNA Content of Simian Immunodeficiency Virions (SIV)

    PubMed Central

    Brameier, Markus; Ibing, Wiebke; Höfer, Katharina; Montag, Judith; Stahl-Hennig, Christiane; Motzkus, Dirk

    2013-01-01

    Recent evidence indicates that regulatory small non-coding RNAs are not only components of eukaryotic cells and vesicles, but also reside within a number of different viruses including retroviral particles. Using ultra-deep sequencing we have comprehensively analyzed the content of simian immunodeficiency virions (SIV), which were compared to mock-control preparations. Our analysis revealed that more than 428,000 sequence reads matched the SIV mac239 genome sequence. Among these we could identify 12 virus-derived small RNAs (vsRNAs) that were highly abundant. Beside known retrovirus-enriched small RNAs, like 7SL-RNA, tRNALys3 and tRNALys isoacceptors, we also identified defined fragments derived from small ILF3/NF90-associated RNA snaR-A14, that were enriched more than 50 fold in SIV. We also found evidence that small nucleolar RNAs U2 and U12 were underrepresented in the SIV preparation, indicating that the relative number or the content of co-isolated exosomes was changed upon infection. Our comprehensive atlas of SIV-incorporated small RNAs provides a refined picture of the composition of retrovirions, which gives novel insights into viral packaging. PMID:24086438

  20. Mapping the small RNA content of simian immunodeficiency virions (SIV).

    PubMed

    Brameier, Markus; Ibing, Wiebke; Höfer, Katharina; Montag, Judith; Stahl-Hennig, Christiane; Motzkus, Dirk

    2013-01-01

    Recent evidence indicates that regulatory small non-coding RNAs are not only components of eukaryotic cells and vesicles, but also reside within a number of different viruses including retroviral particles. Using ultra-deep sequencing we have comprehensively analyzed the content of simian immunodeficiency virions (SIV), which were compared to mock-control preparations. Our analysis revealed that more than 428,000 sequence reads matched the SIV mac239 genome sequence. Among these we could identify 12 virus-derived small RNAs (vsRNAs) that were highly abundant. Beside known retrovirus-enriched small RNAs, like 7SL-RNA, tRNA(Lys3) and tRNA(Lys) isoacceptors, we also identified defined fragments derived from small ILF3/NF90-associated RNA snaR-A14, that were enriched more than 50 fold in SIV. We also found evidence that small nucleolar RNAs U2 and U12 were underrepresented in the SIV preparation, indicating that the relative number or the content of co-isolated exosomes was changed upon infection. Our comprehensive atlas of SIV-incorporated small RNAs provides a refined picture of the composition of retrovirions, which gives novel insights into viral packaging. PMID:24086438

  1. Efficacy of an infection control programme in reducing nosocomial bloodstream infections in a Senegalese neonatal unit.

    PubMed

    Landre-Peigne, C; Ka, A S; Peigne, V; Bougere, J; Seye, M N; Imbert, P

    2011-10-01

    Neonatal nosocomial infections are public health threats in the developing world, and successful interventions are rarely reported. A before-and-after study was conducted in the neonatal unit of the Hôpital Principal de Dakar, Senegal to assess the efficacy of a multi-faceted hospital infection control programme implemented from March to May 2005. The interventions included clustering of nursing care, a simple algorithm for empirical therapy of suspected early-onset sepsis, minimal invasive care and promotion of early discharge of neonates. Data on nosocomial bloodstream infections, mortality, bacterial resistance and antibiotic use were collected before and after implementation of the infection control programme. One hundred and twenty-five infants were admitted immediately before the programme (Period 1, January-February 2005) and 148 infants were admitted immediately after the programme (Period 2, June-July 2005). The two groups of infants were comparable in terms of reason for admission and birth weight. After implementation of the infection control programme, the overall rate of nosocomial bloodstream infections decreased from 8.8% to 2.0% (P=0.01), and the rate of nosocomial bloodstream infections/patient-day decreased from 10.9 to 2.9/1000 patient-days (P=0.03). Overall mortality rates did not differ significantly. The proportion of neonates who received antimicrobial therapy for suspected early-onset sepsis decreased significantly from 100% to 51% of at-risk infants (P<0.001). The incidence of drug-resistant bacteria was significantly lower after implementation of the programme (79% vs 12%; P<0.001), and remained low one year later. In this neonatal unit, simple, low-cost and sustainable interventions led to the control of a high incidence of bacterial nosocomial bloodstream infections, and the efficacy of these interventions was long-lasting. Such interventions could be extended to other low-income countries.

  2. Passive immunotherapies protect WRvFire and IHD-J-Luc vaccinia virus-infected mice from lethality by reducing viral loads in the upper respiratory tract and internal organs.

    PubMed

    Zaitseva, Marina; Kapnick, Senta M; Meseda, Clement A; Shotwell, Elisabeth; King, Lisa R; Manischewitz, Jody; Scott, John; Kodihalli, Shantha; Merchlinsky, Michael; Nielsen, Henriette; Lantto, Johan; Weir, Jerry P; Golding, Hana

    2011-09-01

    Whole-body bioimaging was employed to study the effects of passive immunotherapies on lethality and viral dissemination in BALB/c mice challenged with recombinant vaccinia viruses expressing luciferase. WRvFire and IHD-J-Luc vaccinia viruses induced lethality with similar times to death following intranasal infection, but WRvFire replicated at higher levels than IHD-J-Luc in the upper and lower respiratory tracts. Three types of therapies were tested: licensed human anti-vaccinia virus immunoglobulin intravenous (VIGIV); recombinant anti-vaccinia virus immunoglobulin (rVIG; Symphogen, Denmark), an investigational product containing a mixture of 26 human monoclonal antibodies (HuMAbs) against mature virion (MV) and enveloped virion (EV); and HuMAb compositions targeting subsets of MV or EV proteins. Bioluminescence recorded daily showed that pretreatment with VIGIV (30 mg) or with rVIG (100 μg) on day -2 protected mice from death but did not prevent viral replication at the site of inoculation and dissemination to internal organs. Compositions containing HuMAbs against MV or EV proteins were protective in both infection models at 100 μg per animal, but at 30 μg, only anti-EV antibodies conferred protection. Importantly, the t statistic of the mean total fluxes revealed that viral loads in surviving mice were significantly reduced in at least 3 sites for 3 consecutive days (days 3 to 5) postchallenge, while significant reduction for 1 or 2 days in any individual site did not confer protection. Our data suggest that reduction of viral replication at multiple sites, including respiratory tract, spleen, and liver, as monitored by whole-body bioluminescence can be used to predict the effectiveness of passive immunotherapies in mouse models.

  3. Proteomic Analysis of Mamestra Brassicae Nucleopolyhedrovirus Progeny Virions from Two Different Hosts

    PubMed Central

    Hou, Dianhai; Chen, Xi

    2016-01-01

    Mamestra brassicae nucleopolyhedrovirus (MabrNPV) has a wide host range replication in more than one insect species. In this study, a sequenced MabrNPV strain, MabrNPV-CTa, was used to perform proteomic analysis of both BVs and ODVs derived from two infected hosts: Helicoverpa armigera and Spodoptera exigua. A total of 82 and 39 viral proteins were identified in ODVs and BVs, respectively. And totally, 23 and 76 host proteins were identified as virion-associated with ODVs and BVs, respectively. The host proteins incorporated into the virus particles were mainly involved in cytoskeleton, signaling, vesicle trafficking, chaperone and metabolic systems. Some host proteins, such as actin, cyclophilin A and heat shock protein 70 would be important for viral replication. Several host proteins involved in immune response were also identified in BV, and a C-type lectin protein was firstly found to be associated with BV and its family members have been demonstrated to be involved in entry process of other viruses. This study facilitated the annotation of baculovirus genome, and would help us to understand baculovirus virion structure. Furthermore, the identification of host proteins associated with virions produced in vivo would facilitate investigations on the involvement of intriguing host proteins in virus replication. PMID:27058368

  4. Exocytosis of Alphaherpesvirus Virions, Light Particles, and Glycoproteins Uses Constitutive Secretory Mechanisms

    PubMed Central

    Hogue, Ian B.; Scherer, Julian

    2016-01-01

    ABSTRACT Many molecular and cell biological details of the alphaherpesvirus assembly and egress pathway remain unclear. Recently we developed a live-cell fluorescence microscopy assay of pseudorabies virus (PRV) exocytosis, based on total internal reflection fluorescence (TIRF) microscopy and a virus-encoded pH-sensitive fluorescent probe. Here, we use this assay to distinguish three classes of viral exocytosis in a nonpolarized cell type: (i) trafficking of viral glycoproteins to the plasma membrane, (ii) exocytosis of viral light particles, and (iii) exocytosis of virions. We find that viral glycoproteins traffic to the cell surface in association with constitutive secretory Rab GTPases and exhibit free diffusion into the plasma membrane after exocytosis. Similarly, both virions and light particles use these same constitutive secretory mechanisms for egress from infected cells. Furthermore, we show that viral light particles are distinct from cellular exosomes. Together, these observations shed light on viral glycoprotein trafficking steps that precede virus particle assembly and reinforce the idea that virions and light particles share a biogenesis and trafficking pathway. PMID:27273828

  5. Effectiveness and cost of failure mode and effects analysis methodology to reduce neurosurgical site infections.

    PubMed

    Hover, Alexander R; Sistrunk, William W; Cavagnol, Robert M; Scarrow, Alan; Finley, Phillip J; Kroencke, Audrey D; Walker, Judith L

    2014-01-01

    Mercy Hospital Springfield is a tertiary care facility with 32 000 discharges and 15 000 inpatient surgeries in 2011. From June 2009 through January 2011, a stable inpatient elective neurosurgery infection rate of 2.15% was observed. The failure mode and effects analysis (FMEA) methodology to reduce inpatient neurosurgery infections was utilized. Following FMEA implementation, overall elective neurosurgery infection rates were reduced to 1.51% and sustained through May 2012. Compared with baseline, the post-FMEA deep-space and organ infection rate was reduced by 41% (P = .052). Overall hospital inpatient clean surgery infection rates for the same time frame did not decrease to the same extent, suggesting a specific effect of the FMEA. The study team believes that the FMEA interventions resulted in 14 fewer expected infections, $270 270 in savings, a 168-day reduction in expected length of stay, and 22 fewer readmissions. Given the serious morbidity and cost of health care-associated infections, the study team concludes that FMEA implementation was clinically cost-effective.

  6. Exocytosis of Varicella-Zoster Virus Virions Involves a Convergence of Endosomal and Autophagy Pathways

    PubMed Central

    Buckingham, Erin M.; Jarosinski, Keith W.; Jackson, Wallen; Carpenter, John E.

    2016-01-01

    ABSTRACT Varicella-zoster virus (VZV) is an extremely cell-associated herpesvirus with limited egress of viral particles. The induction of autophagy in VZV-infected monolayers is easily detectable; inhibition of autophagy leads to decreased VZV glycoprotein biosynthesis and diminished viral titers. To explain how autophagic flux could exert a proviral effect on the VZV infectious cycle, we postulated that the VZV exocytosis pathway following secondary envelopment may converge with the autophagy pathway. This hypothesis depended on known similarities between VZV gE and autophagy-related (Atg) Atg9/Atg16L1 trafficking pathways. Investigations were carried out with highly purified fractions of VZV virions. When the virion fraction was tested for the presence of autophagy and endosomal proteins, microtubule-associated protein 1 light chain (MAP1LC3B) and Ras-like GTPase 11 (Rab11) were detected. By two-dimensional (2D) and 3D imaging after immunolabeling, both proteins also colocalized with VZV gE in a proportion of cytoplasmic vesicles. When purified VZV virions were enumerated after immunoelectron microscopy, gold beads were detected on viruses following incubation with antibodies to VZV gE (∼100%), Rab11 (50%), and LC3B (30%). Examination of numerous electron micrographs demonstrated that enveloped virions were housed in single-membraned vesicles; viral particles were not observed in autophagosomes. Taken together, our data suggested that some viral particles after secondary envelopment accumulated in a heterogeneous population of single-membraned vesicular compartments, which were decorated with components from both the endocytic pathway (Rab11) and the autophagy pathway (LC3B). The latter cytoplasmic viral vesicles resembled an amphisome. IMPORTANCE VZV infection leads to increased autophagic flux, while inhibition of autophagy leads to a marked reduction in virus spread. In this investigation of the proviral role of autophagy, we found evidence for an

  7. [Sedimentation characteristics of virion RNA of Machupo virus reproducing in the presence of actinomycin D].

    PubMed

    Golubev, V P; Scheslenok, E P; Finskaia, N N; Lukashevich, I S

    1985-06-01

    Actinomycin D treatment (0.005-05 g/ml) of Vero and BHK-21 cells infected with Machupo virus suppressed the synthesis of ribosomal RNAs but did not affect the production of infectious Machupo virus. Virion RNAs contained 3 high molecular weight RNA species: 28-31 S, 22-24 S and 18 S. In the presence of actinomycin D [3H]-uridine incorporated only in 30-31 S and 22-24 S RNA species. The data are supported by previous results which show that Machupo virus genome contains two RNA species: "large" (30-31 S) and "small" (22-24 S).

  8. The plant host can affect the encapsidation of brome mosaic virus (BMV) RNA: BMV virions are surprisingly heterogeneous.

    PubMed

    Ni, Peng; Vaughan, Robert C; Tragesser, Brady; Hoover, Haley; Kao, C Cheng

    2014-03-01

    Brome mosaic virus (BMV) packages its genomic and subgenomic RNAs into three separate viral particles. BMV purified from barley, wheat, and tobacco have distinct relative abundances of the encapsidated RNAs. We seek to identify the basis for the host-dependent differences in viral RNA encapsidation. Sequencing of the viral RNAs revealed recombination events in the 3' untranslated region of RNA1 of BMV purified from barley and wheat, but not from tobacco. However, the relative amounts of the BMV RNAs that accumulated in barley and wheat are similar and RNA accumulation is not sufficient to account for the difference in RNA encapsidation. Virions purified from barley and wheat were found to differ in their isoelectric points, resistance to proteolysis, and contacts between the capsid residues and the RNA. Mass spectrometric analyses revealed that virions from the three hosts had different post-translational modifications that should impact the physiochemical properties of the virions. Another major source of variation in RNA encapsidation was due to the purification of BMV particles to homogeneity. Highly enriched BMV present in lysates had a surprising range of sizes, buoyant densities, and distinct relative amounts of encapsidated RNAs. These results show that the encapsidated BMV RNAs reflect a combination of host effects on the physiochemical properties of the viral capsids and the enrichment of a subset of virions. The previously unexpected heterogeneity in BMV should influence the timing of the infection and also the host innate immune responses.

  9. Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques.

    PubMed

    Pandrea, Ivona; Xu, Cuiling; Stock, Jennifer L; Frank, Daniel N; Ma, Dongzhu; Policicchio, Benjamin B; He, Tianyu; Kristoff, Jan; Cornell, Elaine; Haret-Richter, George S; Trichel, Anita; Ribeiro, Ruy M; Tracy, Russell; Wilson, Cara; Landay, Alan L; Apetrei, Cristian

    2016-01-01

    Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab-infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection. PMID:26764484

  10. Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques.

    PubMed

    Pandrea, Ivona; Xu, Cuiling; Stock, Jennifer L; Frank, Daniel N; Ma, Dongzhu; Policicchio, Benjamin B; He, Tianyu; Kristoff, Jan; Cornell, Elaine; Haret-Richter, George S; Trichel, Anita; Ribeiro, Ruy M; Tracy, Russell; Wilson, Cara; Landay, Alan L; Apetrei, Cristian

    2016-01-01

    Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab-infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection.

  11. Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques

    PubMed Central

    Pandrea, Ivona; Xu, Cuiling; Stock, Jennifer L.; Frank, Daniel N.; Ma, Dongzhu; Policicchio, Benjamin B.; He, Tianyu; Kristoff, Jan; Cornell, Elaine; Haret-Richter, George S.; Trichel, Anita; Ribeiro, Ruy M.; Tracy, Russell; Wilson, Cara; Landay, Alan L.; Apetrei, Cristian

    2016-01-01

    Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab–infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection. PMID:26764484

  12. Expression of Aedes trypsin-modulating oostatic factor on the virion of TMV: A potential larvicide.

    PubMed

    Borovsky, Dov; Rabindran, Shailaja; Dawson, William O; Powell, Charles A; Iannotti, Donna A; Morris, Timothy J; Shabanowitz, Jeffry; Hunt, Donald F; DeBondt, Hendrik L; DeLoof, Arnold

    2006-12-12

    We report the engineering of the surface of the tobacco mosaic virus (TMV) virion with a mosquito decapeptide hormone, trypsin-modulating oostatic factor (TMOF). The TMV coat protein (CP) was fused to TMOF at the C terminus by using a read-through, leaky stop codon that facilitated expression of CP and chimeric CP-TMOF (20:1 ratio) that were coassembled into virus particles in infected Nicotiana tabacum. Plants that were infected with the hybrid TMV RNA accumulated TMOF to levels of 1.3% of total soluble protein. Infected tobacco leaf discs that were fed to Heliothis virescens fourth-instar larvae stunted their growth and inhibited trypsin and chymotrypsin activity in their midgut. Purified CP-TMOF virions fed to mosquito larvae stopped larval growth and caused death. Because TMV has a wide host range, expressing TMV-TMOF in plants can be used as a general method to protect them against agricultural insect pests and to control vector mosquitoes.

  13. Hypothesis: Impregnated school uniforms reduce the incidence of dengue infections in school children.

    PubMed

    Wilder-Smith, A; Lover, A; Kittayapong, P; Burnham, G

    2011-06-01

    Dengue infection causes a significant economic, social and medical burden in affected populations in over 100 countries in the tropics and sub-tropics. Current dengue control efforts have generally focused on vector control but have not shown major impact. School-aged children are especially vulnerable to infection, due to sustained human-vector-human transmission in the close proximity environments of schools. Infection in children has a higher rate of complications, including dengue hemorrhagic fever and shock syndromes, than infections in adults. There is an urgent need for integrated and complementary population-based strategies to protect vulnerable children. We hypothesize that insecticide-treated school uniforms will reduce the incidence of dengue in school-aged children. The hypothesis would need to be tested in a community based randomized trial. If proven to be true, insecticide-treated school uniforms would be a cost-effective and scalable community based strategy to reduce the burden of dengue in children.

  14. Evidence for translational regulation by the herpes simplex virus virion host shutoff protein.

    PubMed

    Saffran, Holly A; Read, G Sullivan; Smiley, James R

    2010-06-01

    The herpes simplex virus (HSV) virion host shutoff protein (vhs) encoded by gene UL41 is an mRNA-specific RNase that triggers accelerated degradation of host and viral mRNAs in infected cells. We report here that vhs is also able to modulate reporter gene expression without greatly altering the levels of the target mRNA in transient-transfection assays conducted in HeLa cells. We monitored the effects of vhs on a panel of bicistronic reporter constructs bearing a variety of internal ribosome entry sites (IRESs) located between two test cistrons. As expected, vhs inhibited the expression of the 5' cistrons of all of these constructs; however, the response of the 3' cistron varied with the IRES: expression driven from the wild-type EMCV IRES was strongly suppressed, while expression controlled by a mutant EMCV IRES and the cellular ApaF1, BiP, and DAP5 IRES elements was strongly activated. In addition, several HSV type 1 (HSV-1) 5' untranslated region (5' UTR) sequences also served as positive vhs response elements in this assay. IRES activation was also observed in 293 and HepG2 cells, but no such response was observed in Vero cells. Mutational analysis has yet to uncouple the ability of vhs to activate 3' cistron expression from its shutoff activity. Remarkably, repression of 5' cistron expression could be observed under conditions where the levels of the reporter RNA were not correspondingly reduced. These data provide strong evidence that vhs can modulate gene expression at the level of translation and that it is able to activate cap-independent translation through specific cis-acting elements.

  15. US probes: risk of cross infection and ways to reduce it--comparison of cleaning methods.

    PubMed

    Fowler, C; McCracken, D

    1999-10-01

    After their use at ultrasonography (US) in the intensive therapy unit, probes were used to directly inoculate blood agar plates before and after various cleaning procedures. The uncleaned probes transmitted large numbers of clinically important microbes. Simple cleaning methods were effective in reducing transmission among certain patients: fit patients, double paper wipe; patients at risk of contracting infection, single paper wipe followed by alcohol wipe; patients with a potential source of infection, single paper wipe followed by alcohol wipe.

  16. PD-1 blockade during chronic SIV infection reduces hyperimmune activation and microbial translocation in rhesus macaques.

    PubMed

    Dyavar Shetty, Ravi; Velu, Vijayakumar; Titanji, Kehmia; Bosinger, Steven E; Freeman, Gordon J; Silvestri, Guido; Amara, Rama Rao

    2012-05-01

    Hyperimmune activation is a strong predictor of disease progression during pathogenic immunodeficiency virus infections and is mediated in part by sustained type I IFN signaling in response to adventitious microbial infection. The immune inhibitory receptor programmed death-1 (PD-1) regulates functional exhaustion of virus-specific CD8(+) T cells during chronic infections, and in vivo PD-1 blockade has been shown to improve viral control of SIV. Here, we show that PD-1 blockade during chronic SIV infection markedly reduced the expression of transcripts associated with type I IFN signaling in the blood and colorectal tissue of rhesus macaques (RMs). The effect of PD-1 blockade on type I IFN signaling was durable and persisted even under conditions of high viremia. Reduced type I IFN signaling was associated with enhanced expression of some of the junction-associated genes in colorectal tissue and with a profound decrease in plasma LPS levels, suggesting a possible repair of gut-associated junctions and decreased microbial translocation into the blood. PD-1 blockade enhanced immunity to gut-resident pathogenic bacteria, control of gut-associated opportunistic infections, and survival of SIV-infected RMs. Our results suggest PD-1 blockade as a potential novel therapeutic approach to enhance combination antiretroviral therapy by suppressing hyperimmune activation in HIV-infected individuals. PMID:22523065

  17. Using the Pillars of Infection Prevention to Build an Effective Program for Reducing the Transmission of Emerging and Reemerging Infections.

    PubMed

    Branch-Elliman, Westyn; Savor Price, Connie; Bessesen, Mary T; Perl, Trish M

    2015-09-01

    Preventing transmission of emerging infectious diseases remains a challenge for infection prevention and occupational safety programs. The recent Ebola and measles outbreaks highlight the need for pre-epidemic planning, early identification, and appropriate isolation of infected individuals and health care personnel protection. To optimally allocate limited infection control resources, careful consideration of major modes of transmission, the relative infectiousness of the agent, and severity of the pathogen-specific disease are considered. A framework to strategically approach pathogens proposed for health care settings includes generic principles (1) elimination of potential exposure, (2) implementation of administrative controls, (3) facilitation of engineering and environmental controls, and (4) protection of the health care worker and patient using hand hygiene and personal protective equipment. Additional considerations are pre-epidemic vaccination and incremental costs and benefits of infection prevention interventions. Here, major strategies for preventing health-care-associated transmissions are reviewed, including reducing exposure; vaccination; administrative, engineering, and environmental controls; and personal protective equipment. Examples from recent outbreaks are used to highlight key infection prevention aspects and controversies. PMID:26231500

  18. Using the Pillars of Infection Prevention to Build an Effective Program for Reducing the Transmission of Emerging and Reemerging Infections.

    PubMed

    Branch-Elliman, Westyn; Savor Price, Connie; Bessesen, Mary T; Perl, Trish M

    2015-09-01

    Preventing transmission of emerging infectious diseases remains a challenge for infection prevention and occupational safety programs. The recent Ebola and measles outbreaks highlight the need for pre-epidemic planning, early identification, and appropriate isolation of infected individuals and health care personnel protection. To optimally allocate limited infection control resources, careful consideration of major modes of transmission, the relative infectiousness of the agent, and severity of the pathogen-specific disease are considered. A framework to strategically approach pathogens proposed for health care settings includes generic principles (1) elimination of potential exposure, (2) implementation of administrative controls, (3) facilitation of engineering and environmental controls, and (4) protection of the health care worker and patient using hand hygiene and personal protective equipment. Additional considerations are pre-epidemic vaccination and incremental costs and benefits of infection prevention interventions. Here, major strategies for preventing health-care-associated transmissions are reviewed, including reducing exposure; vaccination; administrative, engineering, and environmental controls; and personal protective equipment. Examples from recent outbreaks are used to highlight key infection prevention aspects and controversies.

  19. Movements of HIV-virions in human cervical mucus

    PubMed Central

    Boukari, Hacène; Brichacek, Beda; Stratton, Pamela; Mahoney, Sheila F.; Lifson, Jeffrey D.; Margolis, Leonid; Nossal, Ralph

    2009-01-01

    Time-resolved confocal microscopy and fluorescence correlation spectroscopy were used to examine the movements of fluorescently-labeled HIV virions (~100 nm) added to samples of human cervical mucus. Particle-tracking analysis indicates that the motion of most virions is decreased 200-fold compared to that in aqueous solution and is not driven by typical diffusion. Rather, the time-dependence of their ensemble-averaged mean-square displacements is proportional to τα + v2τ2, describing a combination of anomalous diffusion (α~ 0.3) and flow-like behavior, τ being the lag time. We attribute the flow-like behavior to slowly-relaxing mucus matrix that follows mechanical perturbations such as stretching and twisting of the sample. Further analysis of the tracks and displacements of individual virions indicates differences in the local movements among the virions, including constrained motion and infrequent jumps, perhaps due to abrupt changes in matrix structure. Changes in the microenvironments due to slow structural changes may facilitate movement of the virions, allowing them to reach the epithelial layer. PMID:19711976

  20. A new Hydrocephalus Clinical Research Network protocol to reduce cerebrospinal fluid shunt infection.

    PubMed

    Kestle, John R W; Holubkov, Richard; Douglas Cochrane, D; Kulkarni, Abhaya V; Limbrick, David D; Luerssen, Thomas G; Jerry Oakes, W; Riva-Cambrin, Jay; Rozzelle, Curtis; Simon, Tamara D; Walker, Marion L; Wellons, John C; Browd, Samuel R; Drake, James M; Shannon, Chevis N; Tamber, Mandeep S; Whitehead, William E

    2016-04-01

    OBJECT In a previous report by the same research group (Kestle et al., 2011), compliance with an 11-step protocol was shown to reduce CSF shunt infection at Hydrocephalus Clinical Research Network (HCRN) centers (from 8.7% to 5.7%). Antibiotic-impregnated catheters (AICs) were not part of the protocol but were used off protocol by some surgeons. The authors therefore began using a new protocol that included AICs in an effort to reduce the infection rate further. METHODS The new protocol was implemented at HCRN centers on January 1, 2012, for all shunt procedures (excluding external ventricular drains [EVDs], ventricular reservoirs, and subgaleal shunts). Procedures performed up to September 30, 2013, were included (21 months). Compliance with the protocol and outcome events up to March 30, 2014, were recorded. The definition of infection was unchanged from the authors' previous report. RESULTS A total of 1935 procedures were performed on 1670 patients at 8 HCRN centers. The overall infection rate was 6.0% (95% CI 5.1%-7.2%). Procedure-specific infection rates varied (insertion 5.0%, revision 5.4%, insertion after EVD 8.3%, and insertion after treatment of infection 12.6%). Full compliance with the protocol occurred in 77% of procedures. The infection rate was 5.0% after compliant procedures and 8.7% after noncompliant procedures (p = 0.005). The infection rate when using this new protocol (6.0%, 95% CI 5.1%-7.2%) was similar to the infection rate observed using the authors' old protocol (5.7%, 95% CI 4.6%-7.0%). CONCLUSIONS CSF shunt procedures performed in compliance with a new infection prevention protocol at HCRN centers had a lower infection rate than noncompliant procedures. Implementation of the new protocol (including AICs) was associated with a 6.0% infection rate, similar to the infection rate of 5.7% from the authors' previously reported protocol. Based on the current data, the role of AICs compared with other infection prevention measures is unclear.

  1. Drug treatment of malaria infections can reduce levels of protection transferred to offspring via maternal immunity

    PubMed Central

    Staszewski, Vincent; Reece, Sarah E.; O'Donnell, Aidan J.; Cunningham, Emma J. A.

    2012-01-01

    Maternally transferred immunity can have a fundamental effect on the ability of offspring to deal with infection. However, levels of antibodies in adults can vary both quantitatively and qualitatively between individuals and during the course of infection. How infection dynamics and their modification by drug treatment might affect the protection transferred to offspring remains poorly understood. Using the rodent malaria parasite Plasmodium chabaudi, we demonstrate that curing dams part way through infection prior to pregnancy can alter their immune response, with major consequences for offspring health and survival. In untreated maternal infections, maternally transferred protection suppressed parasitaemia and reduced pup mortality by 75 per cent compared with pups from naïve dams. However, when dams were treated with anti-malarial drugs, pups received fewer maternal antibodies, parasitaemia was only marginally suppressed, and mortality risk was 25 per cent higher than for pups from dams with full infections. We observed the same qualitative patterns across three different host strains and two parasite genotypes. This study reveals the role that within-host infection dynamics play in the fitness consequences of maternally transferred immunity. Furthermore, it highlights a potential trade-off between the health of mothers and offspring suggesting that anti-parasite treatment may significantly affect the outcome of infection in newborns. PMID:22357264

  2. Antipseudomonal Bacteriophage Reduces Infective Burden and Inflammatory Response in Murine Lung

    PubMed Central

    Pabary, Rishi; Singh, Charanjit; Morales, Sandra; Bush, Andrew; Alshafi, Khalid; Bilton, Diana; Alton, Eric W. F. W.; Smithyman, Anthony

    2015-01-01

    As antibiotic resistance increases, there is a need for new therapies to treat infection, particularly in cystic fibrosis (CF), where Pseudomonas aeruginosa is a ubiquitous pathogen associated with increased morbidity and mortality. Bacteriophages are an attractive alternative treatment, as they are specific to the target bacteria and have no documented side effects. The efficacy of phage cocktails was established in vitro. Two P. aeruginosa strains were taken forward into an acute murine infection model with bacteriophage administered either prophylactically, simultaneously, or postinfection. The infective burden and inflammation in bronchoalveolar lavage fluid (BALF) were assessed at various times. With low infective doses, both control mice and those undergoing simultaneous phage treatment cleared P. aeruginosa infection at 48 h, but there were fewer neutrophils in BALF of phage-treated mice (median, 73.2 × 104/ml [range, 35.2 to 102.1 × 104/ml] versus 174 × 104/ml [112.1 to 266.8 × 104/ml], P < 0.01 for the clinical strain; median, 122.1 × 104/ml [105.4 to 187.4 × 104/ml] versus 206 × 104/ml [160.1 to 331.6 × 104/ml], P < 0.01 for PAO1). With higher infective doses of PAO1, all phage-treated mice cleared P. aeruginosa infection at 24 h, whereas infection persisted in all control mice (median, 1,305 CFU/ml [range, 190 to 4,700 CFU/ml], P < 0.01). Bacteriophage also reduced CFU/ml in BALF when administered postinfection (24 h) and both CFU/ml and inflammatory cells in BALF when administered prophylactically. A reduction in soluble inflammatory cytokine levels in BALF was also demonstrated under different conditions. Bacteriophages are efficacious in reducing both the bacterial load and inflammation in a murine model of P. aeruginosa lung infection. This study provides proof of concept for future clinical trials in patients with CF. PMID:26574007

  3. Retroviral env glycoprotein trafficking and incorporation into virions.

    PubMed

    Murakami, Tsutomu

    2012-01-01

    Together with the Gag protein, the Env glycoprotein is a major retroviral structural protein and is essential for forming infectious virus particles. Env is synthesized, processed, and transported to certain microdomains at the plasma membrane and takes advantage of the same host machinery for its trafficking as that used by cellular glycoproteins. Incorporation of Env into progeny virions is probably mediated by the interaction between Env and Gag, in some cases with the additional involvement of certain host factors. Although several general models have been proposed to explain the incorporation of retroviral Env glycoproteins into virions, the actual mechanism for this process is still unclear, partly because structural data on the Env protein cytoplasmic tail is lacking. This paper presents the current understanding of the synthesis, trafficking, and virion incorporation of retroviral Env proteins.

  4. Incorporation of Spike and Membrane Glycoproteins into Coronavirus Virions

    PubMed Central

    Ujike, Makoto; Taguchi, Fumihiro

    2015-01-01

    The envelopes of coronaviruses (CoVs) contain primarily three proteins; the two major glycoproteins spike (S) and membrane (M), and envelope (E), a non-glycosylated protein. Unlike other enveloped viruses, CoVs bud and assemble at the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC). For efficient virion assembly, these proteins must be targeted to the budding site and to interact with each other or the ribonucleoprotein. Thus, the efficient incorporation of viral envelope proteins into CoV virions depends on protein trafficking and protein–protein interactions near the ERGIC. The goal of this review is to summarize recent findings on the mechanism of incorporation of the M and S glycoproteins into the CoV virion, focusing on protein trafficking and protein–protein interactions. PMID:25855243

  5. Selective dansylation of M protein within intact influenza virions

    SciTech Connect

    Robertson, B.H.; Bennett, J.C.; Compans, R.W.

    1982-12-01

    Exposure of purified influenza virions to (/sup 14/C)dansyl chloride resulted in the covalent attachment of the dansyl chromophore to the virion. Gel electrophoresis revealed that the dansyl chromophore was specifically coupled to the internal membrane (M) protein. Purification of the M protein by gel filtration followed by cyanogen bromide cleavage and peptide fractionation revealed that four of six peptide peaks contained dansyl label. Acid hydrolysis of the separated peptide peaks followed by thin-layer chromatography revealed that dansyl label was coupled to lysine residues present in these peptides. The results of these investigations have demonstrated that the M protein molecule is the major viral polypeptide labeled when intact virions are exposed to dansyl chloride.

  6. Inhibition of the receptor-mediated virion attachment to a lipid membrane

    NASA Astrophysics Data System (ADS)

    Zhdanov, Vladimir P.

    2012-10-01

    The forefront of the anti-viral defence is sometimes aimed at virion attachment to a host membrane. This step or, more specifically, virion contacts with cellular membrane receptors (or, e.g., glycolipids) can be inhibited by antibodies (or specially chosen or designed compounds) via their association with virions. In this case, the full-scale attachment of virions to a host membrane occurs via a subtle interplay of the formation and rupture of multiple virion-inhibitor and virion-receptor bonds. We present a kinetic model describing this interplay and illustrating general trends in the process under consideration.

  7. CagA-Positive Helicobacter pylori Infection and Reduced Sperm Motility, Vitality, and Normal Morphology

    PubMed Central

    Moretti, E.; Collodel, G.; Mazzi, L.; Campagna, M. S.; Figura, N.

    2013-01-01

    Helicobacter pylori (HP) infection, particularly when caused by strains expressing CagA, may be considered a concomitant cause of male and female reduced fertility. This study explored, in 87 HP-infected males, the relationship between infection by CagA-positive HP strains and sperm parameters. HP infection and CagA status were determined by ELISA and Western blotting; semen analysis was performed following WHO guidelines. The amino acid sequence of human enzymes involved in glycolysis and oxidative metabolism were “blasted” with peptides expressed by HP J99. Thirty-seven patients (42.5%) were seropositive for CagA. Sperm motility (18% versus 32%; P < 0.01), sperm vitality (35% versus 48%; P < 0.01) and the percentage of sperm with normal forms (18% versus 22%; P < 0.05) in the CagA-positive group were significantly reduced versus those in the CagA-negative group. All the considered enzymes showed partial linear homology with HP peptides, but four enzymes aligned with four different segments of the same cag island protein. We hypothesize a relationship between infection by strains expressing CagA and decreased sperm quality. Potentially increased systemic levels of inflammatory cytokines that occur in infection by CagA-positive strains and autoimmune phenomena that involve molecular mimicry could explain the pathogenetic mechanism of alterations observed. PMID:24167371

  8. Kinetics of Incorporation of Structural Proteins into Sindbis Virions

    PubMed Central

    Scheele, Christina M.; Pfefferkorn, E. R.

    1969-01-01

    The morphogenesis of Sindbis virus was studied by determining the kinetics with which newly synthesized nucleocapsid and envelope proteins appeared in virions released into the extracellular medium. Assembly of the nucleocapsid was more rapid than modification of the cellular membrane by the addition of the viral envelope protein. However, both viral structural proteins were efficiently incorporated into virions; a 0.5-hr pulse-labeling period resulted in the release of maximally labeled virus during the next hour. When protein synthesis was inhibited, release of virus soon declined even though large amounts of both viral structural proteins were present within the cell and ribonucleic acid replication was unaffected. PMID:5771964

  9. Ultrafast Tracking of a Single Live Virion During the Invagination of a Cell Membrane.

    PubMed

    Pan, Yangang; Wang, Shaowen; Shan, Yuping; Zhang, Dinglin; Gao, Jing; Zhang, Min; Liu, Shuheng; Cai, Mingjun; Xu, Haijiao; Li, Guohui; Qin, Qiwei; Wang, Hongda

    2015-06-01

    The first step in most viral infections is the penetration of the cell membrane via endocytosis. However, the underlying mechanism of this important process has not been quantitatively characterized; for example, the velocity and force of a single virion during invagination remain unknown. Here, the endocytosis of a single live virion (Singapore grouper iridovirus, SGIV) through the apical membranes of a host cell is monitored by developing and using a novel ultrafast (at the microsecond level) tracking technique: force tracing. For the first time, these results unambiguously reveal that the maximum velocity during the cell entry of a single SGIV by membrane invagination is approximately 200 nm s(-1), the endocytic force is approximately 60.8 ± 18.5 pN, and the binding energy density increases with the engulfment depth. This report utilizing high temporospatial resolution (subnanometer and microsecond levels) approaches provides new insight into the dynamic process of viral infection via endocytosis and the mechanism of membrane invagination at the single-particle level.

  10. Current Evidence for the Use of Laminar Flow in Reducing Infection Rates in Total Joint Arthroplasty

    PubMed Central

    James, M; Khan, W.S; Nannaparaju, M.R; Bhamra, J.S; Morgan-Jones, R

    2015-01-01

    Since the introduction of laminar air flow in orthopaedic theatres by Sir John Charnley, it has widely become accepted as the standard during orthopaedic procedures such as joint arthroplasty. We present a review of available current literature for the use of laminar flow operating theatre ventilation during total joint arthroplasty and examines the effectiveness of laminar flow ventilated operating theatres in preventing post-operative wound infection. Results of our findings suggest that while bacterial and air particulate is reduced by laminar air flow systems, there is no conclusive effect on the reduction of post-operative wound infections following total joint arthroplasty. We conclude that a combination of strict aseptic technique, prophylactic antibiotics and good anaesthetic control during surgery remains crucial to reduce post-operative surgical infections. PMID:26587068

  11. Vaccinia virus A17L gene product is essential for an early step in virion morphogenesis.

    PubMed

    Rodríguez, D; Esteban, M; Rodríguez, J R

    1995-08-01

    Vaccinia virus (VV) A17L gene encodes a 23-kDa protein that is proteolytically cleaved to generate a 21-kDa product that is incorporated into the viral particles. We have previously shown that the 21-kDa protein forms a stable complex with the VV 14-kDa envelope protein and suggested that the 21-kDa protein may serve to anchor the 14-kDa protein to the envelope of the virion (D. Rodríguez, J. R. Rodríguez, and M. Esteban, J. Virol. 67:3435-3440, 1993). To study the role of the 21-kDa protein in virion assembly, in this investigation we generated a VV recombinant, VVindA17L, that contains an inducible A17L gene regulated by the E. coli repressor/operator system. In the absence of the inducer, shutoff of the A17L gene was complete, and this shutoff correlated with a reduction in virus yields of about 3 log units. Although early and late viral polypeptides are normally synthesized in the absence of the A17L gene product, proteolytic processing of the major p4a and p4b core proteins was clearly impaired under these conditions. Electron microscopy examination of cells infected in the absence of isopropylthiogalactopyranoside (IPTG) revealed that virion morphogenesis was completely arrested at a very early stage, even prior to the formation of crescent-shaped membranes, which are the first distinguishable viral structures. Only electron-dense structures similar to rifampin bodies, but devoid of membranes, could be observed in the cytoplasm of cells infected with VVindA17L under nonpermissive conditions. Considering the most recent assembly model presented by Sodeik et al. (B. Sodeik, R. W. Doms, M. Ericsson, G. Hiller, C. E. Machamer, W. van't Hof, G. van Meer, B. Moss, and G. Griffiths, J. Cell Biol. 121:521-541, 1993), we propose that this protein is targeted to the intermediate compartment and is involved in the recruitment of these membranes to the viral factories, where it forms the characteristic crescent structures that subsequently result in the formation of

  12. Nuclear Export of the Nonenveloped Parvovirus Virion Is Directed by an Unordered Protein Signal Exposed on the Capsid Surface

    PubMed Central

    Maroto, Beatriz; Valle, Noelia; Saffrich, Rainer; Almendral, José M.

    2004-01-01

    It is uncertain whether nonenveloped karyophilic virus particles may actively traffic from the nucleus outward. The unordered amino-terminal domain of the VP2 major structural protein (2Nt) of the icosahedral parvovirus minute virus of mice (MVM) is internal in empty capsids, but it is exposed outside of the shell through the fivefold axis of symmetry in virions with an encapsidated single-stranded DNA genome, as well as in empty capsids subjected to a heat-induced structural transition. In productive infections of transformed and normal fibroblasts, mature MVM virions were found to efficiently exit from the nucleus prior to cell lysis, in contrast to the extended nuclear accumulation of empty capsids. Newly formed mutant viruses lacking the three phosphorylated serine residues of 2Nt were hampered in their exit from the human transformed NB324K nucleus, in correspondence with the capacity of 2Nt to drive microinjected phosphorylated heated capsids out of the nucleus. However, in normal mouse A9 fibroblasts, in which the MVM capsid was phosphorylated at similar sites but with a much lower rate, the nuclear exit of virions and microinjected capsids harboring exposed 2Nt required the infection process and was highly sensitive to inhibition of the exportin CRM1 in the absence of a demonstrable interaction. Thus, the MVM virion exits the nucleus by accessing nonconventional export pathways relying on cell physiology that can be intensified by infection but in which the exposure of 2Nt remains essential for transport. The flexible 2Nt nuclear transport signal may illustrate a common structural solution used by nonenveloped spherical viruses to propagate in undamaged host tissues. PMID:15367635

  13. Hand hygiene in the dental setting: reducing the risk of infection.

    PubMed

    Fluent, Marie T

    2013-09-01

    Hand hygiene remains the single most important measure for reducing the risk of healthcare-associated infections. In the past 20 years, hand-washing recommendations and guidelines have become increasingly complex, and a plethora of products have become available. This article aims to discuss and clarify the fundamentals of appropriate hand hygiene in dentistry. PMID:24564616

  14. A viable simian virus 40 variant with a deletion in the overlapping genes for virion proteins VP1, VP2 and VP3.

    PubMed

    Norkin, L C; Piatak, M

    1982-12-01

    Nucleotide sequence analysis was used to determine the exact location of a deletion in the late region of the SP2 mutant of simian virus 40 (SV40), a viable small-plaque variant isolated from a persistent infection of rhesus monkey kidney cells. The results indicate that six base pairs are deleted from that part of the SV40 genome in which the coding regions for the three virion proteins, VP1, VP2 and VP3, overlap. This implies that all three virion proteins are affected by the deletion. This finding is discussed with respect to the viability of SP2.

  15. Role of the virion host shutoff (vhs) of herpes simplex virus type 1 in latency and pathogenesis.

    PubMed

    Strelow, L I; Leib, D A

    1995-11-01

    The herpes simplex virus type 1 (HSV-1) UL41 gene product, virion host shutoff (vhs), has homologs among five alphaherpesviruses (HSV-1, HSV-2, pseudorabies virus, varicella-zoster virus, and equine herpesvirus 1), suggesting a role for this protein in neurotropism. A mutant virus, termed UL41NHB, which carries a nonsense linker in the UL41 open reading frame at amino acid position 238 was generated. UL41NHB and a marker-rescued virus, UL41NHB-R, were characterized in vitro and tested for their ability to replicate in vitro and in vivo and to establish and reactivate from latency in a mouse eye model. As demonstrated by Western blotting (immunoblotting) and Northern (RNA) blotting procedures, UL41NHB encodes an appropriately truncated vhs protein and, as expected for a vhs null mutant, fails to induce the degradation of cellular glyceraldehyde-3-phosphate dehydrogenase mRNA. The growth of UL41NHB was not significantly altered in one-step growth curves in Vero or mouse C3H/10T1/2 cells but was impaired in corneas, in trigeminal ganglia, and in brains of mice compared with the growth of KOS and UL41NHB-R. As a measure of establishment of latency, quantitative DNA PCR showed that the amount of viral DNA within trigeminal ganglia latently infected with UL41NHB was reduced by approximately 30-fold compared with that in KOS-infected ganglia and by 50-fold compared with that in UL41NHB-R-infected ganglia. Explant cocultivation studies revealed a low reactivation frequency for UL41NHB (1 of 28 ganglia, or 4%) compared with that for KOS (56 of 76, or 74%) or UL41NHB-R (13 of 20 or 65%). Taken together, these results demonstrate that vhs represents a determinant of viral pathogenesis.

  16. Reducing infection risk in implant-based breast-reconstruction surgery: challenges and solutions

    PubMed Central

    Ooi, Adrian SH; Song, David H

    2016-01-01

    Implant-based procedures are the most commonly performed method for postmastectomy breast reconstruction. While donor-site morbidity is low, these procedures are associated with a higher risk of reconstructive loss. Many of these are related to infection of the implant, which can lead to prolonged antibiotic treatment, undesired additional surgical procedures, and unsatisfactory results. This review combines a summary of the recent literature regarding implant-related breast-reconstruction infections and combines this with a practical approach to the patient and surgery aimed at reducing this risk. Prevention of infection begins with appropriate reconstructive choice based on an assessment and optimization of risk factors. These include patient and disease characteristics, such as smoking, obesity, large breast size, and immediate reconstructive procedures, as well as adjuvant therapy, such as radiotherapy and chemotherapy. For implant-based breast reconstruction, preoperative planning and organization is key to reducing infection. A logical and consistent intraoperative and postoperative surgical protocol, including appropriate antibiotic choice, mastectomy-pocket creation, implant handling, and considered acellular dermal matrix use contribute toward the reduction of breast-implant infections. PMID:27621667

  17. Caspase inhibition reduces lymphocyte apoptosis and improves host immune responses to Trypanosoma cruzi infection.

    PubMed

    Silva, Elisabeth M; Guillermo, Landi V C; Ribeiro-Gomes, Flávia L; De Meis, Juliana; Nunes, Marise P; Senra, Juliana F V; Soares, Milena B P; DosReis, George A; Lopes, Marcela F

    2007-03-01

    In experimental Chagas' disease, lymphocytes from mice infected with Trypanosoma cruzi show increased apoptosis in vivo and in vitro. Treatment with a pan-caspase blocker peptide inhibited expression of the active form of effector caspase-3 in vitro and rescued both B and T cells from cell death. Injection of the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethyl ketone, but not a control peptide, reduced parasitemia and lymphocyte apoptosis in T. cruzi-infected mice. Moreover, treatment with caspase inhibitor throughout acute infection increased the absolute numbers of B and T cells in the spleen and lymph nodes, without affecting cell infiltrates in the heart. Following treatment, we found increased accumulation of memory/activated CD4 and CD8 T cells, and secretion of IFN-gamma by splenocytes stimulated with T. cruzi antigens. Caspase inhibition in the course of infection reduced the intracellular load of parasites in peritoneal macrophages, and increased the production of TNF-alpha and nitric oxide upon activation in vitro. Our results indicate that inhibition of caspases with a pan-caspase blocker peptide improves protective type-1 immune responses to T. cruzi infection. We suggest that mechanisms of apoptosis are potential therapeutic targets in Chagas' disease.

  18. Reducing infection risk in implant-based breast-reconstruction surgery: challenges and solutions

    PubMed Central

    Ooi, Adrian SH; Song, David H

    2016-01-01

    Implant-based procedures are the most commonly performed method for postmastectomy breast reconstruction. While donor-site morbidity is low, these procedures are associated with a higher risk of reconstructive loss. Many of these are related to infection of the implant, which can lead to prolonged antibiotic treatment, undesired additional surgical procedures, and unsatisfactory results. This review combines a summary of the recent literature regarding implant-related breast-reconstruction infections and combines this with a practical approach to the patient and surgery aimed at reducing this risk. Prevention of infection begins with appropriate reconstructive choice based on an assessment and optimization of risk factors. These include patient and disease characteristics, such as smoking, obesity, large breast size, and immediate reconstructive procedures, as well as adjuvant therapy, such as radiotherapy and chemotherapy. For implant-based breast reconstruction, preoperative planning and organization is key to reducing infection. A logical and consistent intraoperative and postoperative surgical protocol, including appropriate antibiotic choice, mastectomy-pocket creation, implant handling, and considered acellular dermal matrix use contribute toward the reduction of breast-implant infections.

  19. Reducing infection risk in implant-based breast-reconstruction surgery: challenges and solutions.

    PubMed

    Ooi, Adrian Sh; Song, David H

    2016-01-01

    Implant-based procedures are the most commonly performed method for postmastectomy breast reconstruction. While donor-site morbidity is low, these procedures are associated with a higher risk of reconstructive loss. Many of these are related to infection of the implant, which can lead to prolonged antibiotic treatment, undesired additional surgical procedures, and unsatisfactory results. This review combines a summary of the recent literature regarding implant-related breast-reconstruction infections and combines this with a practical approach to the patient and surgery aimed at reducing this risk. Prevention of infection begins with appropriate reconstructive choice based on an assessment and optimization of risk factors. These include patient and disease characteristics, such as smoking, obesity, large breast size, and immediate reconstructive procedures, as well as adjuvant therapy, such as radiotherapy and chemotherapy. For implant-based breast reconstruction, preoperative planning and organization is key to reducing infection. A logical and consistent intraoperative and postoperative surgical protocol, including appropriate antibiotic choice, mastectomy-pocket creation, implant handling, and considered acellular dermal matrix use contribute toward the reduction of breast-implant infections. PMID:27621667

  20. Using reduced personal protective equipment in an endemically infected mouse colony.

    PubMed

    Baker, Samuel W; Prestia, Kevin A; Karolewski, Brian

    2014-05-01

    Personal protective equipment (PPE) frequently is used to reduce the risk of spreading adventitial diseases in rodent colonies. The PPE worn often reflects the historic practices of the research institution rather than published performance data. Standard PPE for a rodent facility typically consists of a disposable hair bonnet, gown, face mask, shoe covers, and gloves, which are donned on facility entry and removed on exiting. This study evaluated the effect of a reduced PPE protocol on disease spread within an endemically infected mouse colony. In the reduced protocol, only the parts of the wearer that came in direct contact with the mice or their environment were covered with PPE. To test the reduced PPE protocol, proven naïve mice were housed in a facility endemically infected with murine norovirus and mouse hepatitis virus for 12 wk. During that time, routine husbandry operations were conducted by using either the standard or reduced PPE protocols. All study mice remained free of virus antibody when reduced PPE was implemented. These results indicate that reduced PPE is adequate for disease containment when correct techniques for handling microisolation caging are used. Reducing the amount of PPE used in an animal facility affords considerable cost savings yet limits the risk of disease spread. PMID:24827569

  1. Using Reduced Personal Protective Equipment in an Endemically Infected Mouse Colony

    PubMed Central

    Baker, Samuel W; Prestia, Kevin A; Karolewski, Brian

    2014-01-01

    Personal protective equipment (PPE) frequently is used to reduce the risk of spreading adventitial diseases in rodent colonies. The PPE worn often reflects the historic practices of the research institution rather than published performance data. Standard PPE for a rodent facility typically consists of a disposable hair bonnet, gown, face mask, shoe covers, and gloves, which are donned on facility entry and removed on exiting. This study evaluated the effect of a reduced PPE protocol on disease spread within an endemically infected mouse colony. In the reduced protocol, only the parts of the wearer that came in direct contact with the mice or their environment were covered with PPE. To test the reduced PPE protocol, proven naïve mice were housed in a facility endemically infected with murine norovirus and mouse hepatitis virus for 12 wk. During that time, routine husbandry operations were conducted by using either the standard or reduced PPE protocols. All study mice remained free of virus antibody when reduced PPE was implemented. These results indicate that reduced PPE is adequate for disease containment when correct techniques for handling microisolation caging are used. Reducing the amount of PPE used in an animal facility affords considerable cost savings yet limits the risk of disease spread. PMID:24827569

  2. Role of herpes simplex virus ICP27 in the degradation of mRNA by virion host shutoff RNase.

    PubMed

    Taddeo, Brunella; Zhang, Weiran; Roizman, Bernard

    2010-10-01

    The virion host shutoff (VHS) RNase tegument protein released into cells by infecting virus has two effects. Preexisting stable mRNAs (e.g., GAPDH [glyceraldehyde-3-phosphate dehydrogenase]) are rapidly degraded. Stress response RNAs containing AU-rich elements (AREs) in the 3' untranslated region (3'UTR) are deadenylated and cleaved, but the cleavage products persist for hours, in contrast to the short half-lives of ARE-containing mRNAs in uninfected cells. At late times, the VHS RNase is neutralized by the viral structural proteins VP16 and VP22. A recent study (J. A. Corcoran, W. L. Hsu, and J. R. Smiley, J. Virol. 80:9720-9729, 2006) reported that, at relatively late times after infection, ARE RNAs are rapidly degraded in cells infected with DeltaICP27 mutant virus and concluded that ICP27 "stabilizes" ARE mRNAs. We report the following. (i) The rates of degradation of ARE mRNA at early times (3 h) after infection with the wild type or the DeltaICP27 mutant virus are virtually identical, and hence ICP27 plays no role in this process. (ii) In noncomplementing cells, VHS RNase or VP22 is not synthesized. Therefore, the only VHS that is active is brought into cells by the DeltaICP27 mutant. (ii) The VHS RNase brought into the cells by the DeltaICP27 virus is reduced in potency relative to that of wild-type virus. Hence the rapid degradation of ARE mRNAs noted in DeltaICP27 mutant-infected cells at late times is similar to that taking place in mock-infected or in DeltaVHS RNase mutant-virus-infected cells and does not by itself support the hypothesis that ICP27 stabilizes ARE mRNAs. (iii) Concurrently, we present the first evidence that VHS RNase interacts with ICP27 most likely when bound to cap- and poly(A)-binding proteins, respectively.

  3. Filter-feeding bivalves can remove avian influenza viruses from water and reduce infectivity

    PubMed Central

    Faust, Christina; Stallknecht, David; Swayne, David; Brown, Justin

    2009-01-01

    Avian influenza (AI) viruses are believed to be transmitted within wild aquatic bird populations through an indirect faecal–oral route involving contaminated water. This study examined the influence of filter-feeding bivalves, Corbicula fluminea, on the infectivity of AI virus in water. Clams were placed into individual flasks with distilled water inoculated 1:100 with a low pathogenic (LP) AI virus (A/Mallard/MN/190/99 (H3N8)). Viral titres in water with clams were significantly lower at 24 and 48 h post-inoculation compared to LPAI-infected water without clams. To determine whether clams affected the infectivity of AI viruses, 18 wood ducks (Aix sponsa) were divided into test groups and inoculated with a variety of treatments of clam supernatants, whole clams and water exposed to a high pathogenic (HP) AI (A/whooper swan/Mongolia/244/05 (H5N1)). None of the wood ducks inoculated with HPAI-infected water that was filtered by clams or that was inoculated with or fed tissue from these clams exhibited morbidity or mortality. All wood ducks exposed to either HPAI-infected water without clams or the original viral inoculum died. These results indicate that filter-feeding bivalves can remove and reduce the infectivity of AI viruses in water and demonstrate the need to examine biotic environmental factors that can influence AI virus transmission. PMID:19656788

  4. So Near and Yet So Far: Harmonic Radar Reveals Reduced Homing Ability of Nosema Infected Honeybees

    PubMed Central

    Wolf, Stephan; McMahon, Dino P.; Lim, Ka S.; Pull, Christopher D.; Clark, Suzanne J.; Paxton, Robert J.; Osborne, Juliet L.

    2014-01-01

    Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen - Nosema ceranae (Microsporidia) - on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed. PMID:25098331

  5. So near and yet so far: harmonic radar reveals reduced homing ability of Nosema infected honeybees.

    PubMed

    Wolf, Stephan; McMahon, Dino P; Lim, Ka S; Pull, Christopher D; Clark, Suzanne J; Paxton, Robert J; Osborne, Juliet L

    2014-01-01

    Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen--Nosema ceranae (Microsporidia)--on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed.

  6. ANTIBODY FUSIONS REDUCE ONSET OF EXPERIMENTAL CRYPTOSPORIDIUM PARVUM INFECTION IN CALVES

    PubMed Central

    Imboden, Michael; Schaefer, Deborah A.; Bremel, Robert D.; Homan, E. Jane; Riggs, Michael W.

    2012-01-01

    Cryptosporidium parvum is one of the main causes of diarrhea in neonatal calves resulting in significant morbidity and economic losses for producers worldwide. We have previously demonstrated efficacy of a new class of antimicrobial antibody fusions in a neonatal mouse model for C. parvum infection. Here, we extend efficacy testing of these products to experimental infection in calves, the principal target species. Neonatal calves were challenged with C. parvum oocysts and concomitantly treated with antibody-biocide fusion 4H9-G1-LL37 over the course of four days. This resulted in reduced severity of the disease when compared to control animals. Overall clinical health parameters showed significant improvement in treated animals. Oocyst shedding was reduced in treated when compared to control animals. Control of oocyst shedding is a prerequisite for breaking the cycle of re-infection on dairy farms. Antibody-biocide fusion products thus have the potential to reduce the impact of the infection in both individual animals and in the herd. PMID:22455725

  7. Colorimetric Focus-Forming Assay with Automated Focus Counting by Image Analysis for Quantification of Infectious Hepatitis C Virions

    PubMed Central

    Kang, Wonseok; Shin, Eui-Cheol

    2012-01-01

    Hepatitis C virus (HCV) infection is the leading cause of liver transplantation in Western countries. Studies of HCV infection using cell culture-produced HCV (HCVcc) in vitro systems require quantification of infectious HCV virions, which has conventionally been performed by immunofluorescence-based focus-forming assay with manual foci counting; however, this is a laborious and time-consuming procedure with potentially biased results. In the present study, we established and optimized a method for convenient and objective quantification of HCV virions by colorimetric focus-forming assay with automated focus counting by image analysis. In testing different enzymes and chromogenic substrates, we obtained superior foci development using alkaline phosphatase-conjugated secondary antibody with BCIP/NBT chromogenic substrate. We additionally found that type I collagen coating minimized cell detachment during vigorous washing of the assay plate. After the colorimetric focus-forming assay, the foci number was determined using an ELISpot reader and image analysis software. The foci number and the calculated viral titer determined by this method strongly correlated with those determined by immunofluorescence-based focus-forming assay and manual foci counting. These results indicate that colorimetric focus-forming assay with automated focus counting by image analysis is applicable as a more-efficient and objective method for quantification of infectious HCV virions. PMID:22937136

  8. Targeting α4β7 integrin reduces mucosal transmission of SIV and protects GALT from infection

    PubMed Central

    Byrareddy, Siddappa N.; Kallam, Brianne; Arthos, James; Cicala, Claudia; Nawaz, Fatima; Hiatt, Joseph; Kersh, Ellen N.; McNicholl, Janet M.; Hanson, Debra; Reimann, Keith A.; Brameier, Markus; Walter, Lutz; Rogers, Kenneth; Mayne, Ann E.; Dunbar, Paul; Villinger, Tara; Little, Dawn; Parslow, Tristram G.; Santangelo, Philip J.; Villinger, Francois; Fauci, Anthony S.; Ansari, Aftab A.

    2014-01-01

    α4β7 integrin expressing CD4+ T cells preferentially traffic to gut-associated lymphoid tissues (GALT) and play a key role in HIV/SIV pathogenesis. The administration of an anti-α4β7 monoclonal antibody during acute infection protects macaques from transmission following repeated low-dose intra-vaginal challenges with SIVmac251. In treated animals that became infected the GALT was significantly protected and CD4+ T–cell numbers were maintained. Thus, targeting α4β7 reduces mucosal transmission of SIV in macaques. PMID:25419708

  9. α1-Antitrypsin reduces rhinovirus infection in primary human airway epithelial cells exposed to cigarette smoke

    PubMed Central

    Berman, Reena; Jiang, Di; Wu, Qun; Chu, Hong Wei

    2016-01-01

    Human rhinovirus (HRV) infections target airway epithelium and are the leading cause of acute exacerbations of COPD. Cigarette smoke (CS) increases the severity of viral infections, but there is no effective therapy for HRV infection. We determined whether α1-antitrypsin (A1AT) reduces HRV-16 infection in CS-exposed primary human airway epithelial cells. Brushed bronchial epithelial cells from normal subjects and patients diagnosed with COPD were cultured at air–liquid interface to induce mucociliary differentiation. These cells were treated with A1AT or bovine serum albumin for 2 hours and then exposed to air or whole cigarette smoke (WCS) with or without HRV-16 (5×104 50% Tissue Culture Infective Dose [TCID50]/transwell) infection for 24 hours. WCS exposure significantly increased viral load by an average of fivefold and decreased the expression of antiviral genes interferon-λ1, OAS1, and MX1. When A1AT was added to WCS-exposed cells, viral load significantly decreased by an average of 29-fold. HRV-16 infection significantly increased HRV-16 receptor intercellular adhesion molecule-1 messenger RNA expression in air-exposed cells, which was decreased by A1AT. A1AT-mediated reduction of viral load was not accompanied by increased epithelial antiviral gene expression or by inhibiting the activity of 3C protease involved in viral replication or maturation. Our findings demonstrate that A1AT treatment prevents a WCS-induced increase in viral load and for the first time suggest a therapeutic effect of A1AT on HRV infection. PMID:27354786

  10. Large-scale preparation of UV-inactivated SARS coronavirus virions for vaccine antigen.

    PubMed

    Tsunetsugu-Yokota, Yasuko

    2008-01-01

    In general, a whole virion serves as a simple vaccine antigen and often essential material for the analysis of immune responses against virus infection. However, to work with highly contagious pathogens, it is necessary to take precautions against laboratory-acquired infection. We have learned many lessons from the recent outbreak of severe acute respiratory syndrome (SARS). In order to develop an effective vaccine and diagnostic tools, we prepared UV-inactivated SARS coronavirus on a large scale under the strict Biosafety Level 3 (BSL3) regulation. Our protocol for large-scale preparation of UV-inactivated SARS-CoV including virus expansion, titration, inactivation, and ultracentrifugation is applicable to any newly emerging virus we might encounter in the future.

  11. Enhancement of the Musca domestica hytrosavirus infection with orally delivered reducing agents.

    PubMed

    Boucias, D; Baniszewski, J; Prompiboon, P; Lietze, V; Geden, C

    2015-01-01

    House flies (Musca domestica L.) throughout the world are infected with the salivary gland hypertrophy virus MdSGHV (Hytrosaviridae). Although the primary route of infection is thought to be via ingestion, flies that are old enough to feed normally are resistant to infection per os, suggesting that the peritrophic matrix (PM) is a barrier to virus transmission. Histological examination of the peritrophic matrix of healthy flies revealed a multilaminate structure produced by midgut cells located near the proventriculus. SEM revealed the PM to form a confluent sheet surrounding the food bolus with pores/openings less than 10nm in diameter. TEM revealed the PM to be multilayered, varying in width from 350 to 900 nm, and generally thinner in male than in female flies. When flies were fed on the reducing agents dithiothetriol (DTT) or tris (2-caboxyethyl)phosphine hydrochloride (TCEP) for 48 h before per os exposure to the virus, infection rates increased 10- to 20-fold compared with flies that did not receive the reducing agent treatments. PM's from flies treated with DTT and TCEP displayed varying degrees of disruption, particularly in the outer layer, and lacked the electron-dense inner layer facing the ectoperitrophic space. Both drugs were somewhat toxic to the flies, resulting in>40% mortality at doses greater than 10mM (DTT) or 5 mM (TCEP). DTT increased male fly susceptibility (55.1% infected) more than that of females (7.8%), whereas TCEP increased susceptibility of females (42.9%) more than that of males (26.2%). The cause for the sex differences in response to oral exposure the reducing agents is unclear. Exposing flies to food treated with virus and the reducing agents at the same time, rather than pretreating flies with the drugs, had no effect on susceptibility to the virus. Presumably, the reducing agent disrupted the enveloped virus and acted as a viricidal agent. In summary, it is proposed that the reducing agents influence integrity of the PM barrier

  12. Tomato spotted wilt virus infection reduces the fitness of a nonvector herbivore on pepper.

    PubMed

    Pan, Huipeng; Chen, Gong; Li, Fei; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Liu, Baiming; Xu, Baoyun; Zhang, Youjun

    2013-04-01

    Plant pathogens and insect herbivores often share hosts under natural conditions. Hence, pathogen-induced changes in a host plant can affect the herbivore and vice versa. Even though plant viruses are ubiquitous in the field, little is known about plant-mediated interactions between viruses and nonvector herbivores. Here we tested whether the performance of the sweet potato whitefly, Bemisia tabaci (Gennadius) biotype Q, was altered when raised on pepper infected with Tomato spotted wilt virus (TSWV). TSWV infection reduced B. tabaci fecundity and longevity and increased B. tabaci developmental time but did not affect the insect's survival or female body lengths. Our results demonstrate that TSWV infection can decrease the fitness of B. tabaci biotype Q on pepper plants.

  13. AcMNPV Core Gene ac109 Is Required for Budded Virion Transport to the Nucleus and for Occlusion of Viral Progeny

    PubMed Central

    Alfonso, Victoria; Maroniche, Guillermo A.; Reca, Sol R.; López, María Gabriela; del Vas, Mariana; Taboga, Oscar

    2012-01-01

    The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 core gene has been previously characterized as an essential late gene. Our results showed that budded virions could be detected in supernatants of infected Sf-9 cells, even when ac109 knockout viruses displayed a single-cell infection phenotype. Moreover, confocal microscopy analysis revealed that budded virions can enter the cytoplasm but are unable to enter the cell nucleus. This defect could be repaired by complementing ac109 in trans. In addition, polyhedra of normal size could be detected in Sf-9 nuclei infected with ac109 knockout viruses. However, electron microscopy demonstrated that these occlusion bodies were empty. Altogether, these results indicate that ac109 is required for infectivity of both phenotypes of virus. PMID:23049963

  14. Cucumber Mosaic Virus as a carotenoid inhibitor reducing Phelipanche aegyptiaca infection in tobacco plants.

    PubMed

    Ibdah, Mwafaq; Dubey, Neeraj Kumar; Eizenberg, Hanan; Dabour, Ziad; Abu-Nassar, Jacklin; Gal-On, Amit; Aly, Radi

    2014-01-01

    Cucumber Mosaic Virus (CMV) is a highly infectious cucumovirus, which infects more than 800 plant species and causes major diseases in greenhouse and field crops worldwide. Parasitic weeds such as Phelipanche aegyptiaca are a major constraint to the production of many crops in the world and the parasite's lifestyle makes control extremely difficult. The parasite seeds can germinate after conditioning and perceiving strigolactones secreted by the host roots. Strigolactones are rhizosphere signaling molecules in plants that are biosynthesized through carotenoid cleavage. In the present study we investigated the possibility of reducing β-carotene and then strigolactone production in the host roots by blocking carotenoid biosynthesis using CMV-infected tobacco. It was found that CMV downregulated the enzyme phytoene desaturase(PDS) and reduced significantly both carotenoid production and Phelipanche infection in tobacco host roots infected with both CMV and P. aegyptiaca. Based on our results (decrease of β-carotene and repression of PDS transcripts in tobacco roots), we hypothesized that the reduction of Phelipanche tubercles and shoots occurred due to an effect of CMV on secondary metabolite stimulators such as strigolacetones. Our study indicated that mass production of the host roots was not affected by CMV; however, most inflorescences of Phelipanche grown on CMV-infected tobacco developed abnormally (deformed shoots and short nodes). Carotenoid biosynthesis inhibitors such as CMV can be used to reduce the production of strigolactones, which will lead to decreased Phelipanche attachment. Interestingly, attenuated CMV strains may provide a safe means for enhancing crop resistance against parasitic weeds in a future plan.

  15. Cucumber Mosaic Virus as a carotenoid inhibitor reducing Phelipanche aegyptiaca infection in tobacco plants

    PubMed Central

    Ibdah, Mwafaq; Dubey, Neeraj Kumar; Eizenberg, Hanan; Dabour, Ziad; Abu-Nassar, Jacklin; Gal-On, Amit; Aly, Radi

    2014-01-01

    Cucumber Mosaic Virus (CMV) is a highly infectious cucumovirus, which infects more than 800 plant species and causes major diseases in greenhouse and field crops worldwide. Parasitic weeds such as Phelipanche aegyptiaca are a major constraint to the production of many crops in the world and the parasite's lifestyle makes control extremely difficult. The parasite seeds can germinate after conditioning and perceiving strigolactones secreted by the host roots. Strigolactones are rhizosphere signaling molecules in plants that are biosynthesized through carotenoid cleavage. In the present study we investigated the possibility of reducing β-carotene and then strigolactone production in the host roots by blocking carotenoid biosynthesis using CMV-infected tobacco. It was found that CMV downregulated the enzyme phytoene desaturase(PDS) and reduced significantly both carotenoid production and Phelipanche infection in tobacco host roots infected with both CMV and P. aegyptiaca. Based on our results (decrease of β-carotene and repression of PDS transcripts in tobacco roots), we hypothesized that the reduction of Phelipanche tubercles and shoots occurred due to an effect of CMV on secondary metabolite stimulators such as strigolacetones. Our study indicated that mass production of the host roots was not affected by CMV; however, most inflorescences of Phelipanche grown on CMV-infected tobacco developed abnormally (deformed shoots and short nodes). Carotenoid biosynthesis inhibitors such as CMV can be used to reduce the production of strigolactones, which will lead to decreased Phelipanche attachment. Interestingly, attenuated CMV strains may provide a safe means for enhancing crop resistance against parasitic weeds in a future plan. PMID:25482816

  16. Drug Treatment Combined with BCG Vaccination Reduces Disease Reactivation in Guinea Pigs Infected with Mycobacterium tuberculosis

    PubMed Central

    Shang, Shaobin; Shanley, Crystal A.; Caraway, Megan L.; Orme, Eileen A.; Henao-Tamayo, Marcela; Hascall-Dove, Laurel; Ackart, David; Orme, Ian M.; Ordway, Diane J.; Basaraba, Randall J.

    2012-01-01

    Bacillus-Calmette-Guerin (BCG), the only human tuberculosis vaccine, primes a partially protective immune response against M. tuberculosis infection in humans and animals. In guinea pigs, BCG vaccination slows the progression of disease and reduces the severity of necrotic granulomas, which harbor a population of drug-tolerant bacilli. The objective of this study was to determine if reducing disease severity by BCG vaccination of guinea pigs prior to M. tuberculosis challenge enhanced the efficacy of combination drug therapy. At 20 days of infection, treatment of vaccinated and non-vaccinated animals with rifampin, isoniazid, and pyrizinamide (RHZ) was initiated for 4 or 8 weeks. On days 50, 80 and 190 of infection (10 weeks after drug were withdrawn), treatment efficacy was evaluated by quantifying clinical condition, bacterial loads, lesion severity, and dynamic changes in peripheral blood and lung leukocyte numbers by flow cytometry. In a separate, long-term survival study, treatment efficacy was evaluated by determining disease reactivation frequency post-mortem. BCG vaccination alone delayed pulmonary and extra-pulmonary disease progression, but failed to prevent dissemination of bacilli and the formation of necrotic granulomas. Drug therapy either alone or in combination with BCG, was more effective at lessening clinical disease and lesion severity compared to control animals or those receiving BCG alone. Fewer residual lesions in BCG vaccinated and drug treated animals, equated to a reduced frequency of reactivation disease and improvement in survival even out to 500 days of infection. The combining of BCG vaccination and drug therapy was more effective at resolving granulomas such that fewer animals had evidence of residual infection and thus less reactivation disease. PMID:22244979

  17. Reduced immune responsiveness and lymphoid depletion in mice infected with Ehrlichia risticii.

    PubMed Central

    Rikihisa, Y; Johnson, G C; Burger, C J

    1987-01-01

    The histopathology of the thymus and spleen and the response of spleen cells to mitogenic stimuli were evaluated in Sprague-Dawley CF-1 mice infected with Ehrlichia risticii. Intraperitoneal injection of 10(4) or 10(6) E. risticii-infected U-937 cells into mice resulted in 100% morbidity and partial mortality. Thymic atrophy became significant between 1 and 2 weeks postinfection and remained for the duration of the study. The atrophy appeared associated with antecedent destruction and rarefaction of lymphocytes, resulting in the loss of corticomedullary demarcation. Splenomegaly was prominent; significantly increased weights were detected 7 days postinfection. Histopathologic examination revealed rarefaction of lymphocytes around central arteries, the presence of necrotic debris in histiocytes, and replacement of erythropoiesis by granulopoiesis in the red pulp. Marked and acute reduction of in vitro proliferative responses of spleen cells to concanavalin A (ConA) and phytohemagglutinin were observed in mice infected with 10(4) or 10(6) E. risticii-infected U-937 cells. Interleukin-2 activity in the supernatant of ConA-stimulated spleen cells was also severely reduced. Both changes were time- and dose-dependent and were not associated with decreased spleen cell viability. Neither morbidity nor mortality occurred in mice infected with 10(2) E. risticii-infected U-937 cells. Although there was temporal reduction in phytohemagglutinin-driven lymphocyte proliferation, reduction in neither ConA-driven lymphocyte proliferation nor interleukin-2 activity was observed with this dosage. All E. risticii-inoculated mice seroconverted between days 18 and 25, as detected by the indirect fluorescent-antibody procedure. The findings indicate for the first time the hypoimmune responsiveness and histopathologic changes in lymphoid organs associated with E. risticii infection. Images PMID:3497879

  18. In vivo treatment of Helicobacter pylori infection with liposomal linolenic acid reduces colonization and ameliorates inflammation

    PubMed Central

    Thamphiwatana, Soracha; Gao, Weiwei; Obonyo, Marygorret; Zhang, Liangfang

    2014-01-01

    Helicobacter pylori infection is marked by a vast prevalence and strong association with various gastric diseases, including gastritis, peptic ulcers, and gastric cancer. Because of the rapid emergence of H. pylori strains resistant to existing antibiotics, current treatment regimens show a rapid decline of their eradication rates. Clearly, novel antibacterial strategies against H. pylori are urgently needed. Here, we investigated the in vivo therapeutic potential of liposomal linolenic acid (LipoLLA) for the treatment of H. pylori infection. The LipoLLA formulation with a size of ∼100 nm was prone to fusion with bacterial membrane, thereby directly releasing a high dose of linolenic acids into the bacterial membrane. LipoLLA penetrated the mucus layer of mouse stomach, and a significant portion of the administered LipoLLA was retained in the stomach lining up to 24 h after the oral administration. In vivo tests further confirmed that LipoLLA was able to kill H. pylori and reduce bacterial load in the mouse stomach. LipoLLA treatment was also shown to reduce the levels of proinflammatory cytokines including interleukin 1β, interleukin 6, and tumor necrosis factor alpha, which were otherwise elevated because of the H. pylori infection. Finally, a toxicity test demonstrated excellent biocompatibility of LipoLLA to normal mouse stomach. Collectively, results from this study indicate that LipoLLA is a promising, effective, and safe therapeutic agent for the treatment of H. pylori infection. PMID:25422427

  19. Adoptive transfer of macrophages from adult mice reduces mortality in mice infected with human enterovirus 71.

    PubMed

    Liu, Jiangning; Li, Xiaoying; Fan, Xiaoxu; Ma, Chunmei; Qin, Chuan; Zhang, Lianfeng

    2013-02-01

    Human enterovirus 71 (EV71) causes hand, foot and mouth disease in children under 6 years of age, and the neurological complications of this virus can lead to death. Until now, no vaccines or drugs have been available for the clinical control of this epidemic. Macrophages can engulf pathogens and mediate a series of host immune responses that play a role in the defence against infectious diseases. Using immunohistochemistry, we observed the localizations of virus in muscle tissues of EV71-infected mice. The macrophages isolated from the adult mice could kill the virus gradually in vitro, as shown using quantitative real-time PCR (qRT-PCR) and virus titration. Co-localisation of lysosomes and virus within macrophages suggested that the lysosomes were possibly responsible for the phagocytosis of EV71. Activation of the macrophages in the peritoneal cavity of mice four days pre-infection reduced the mortality of mice upon lethal EV71 infection. The adoptive transfer of macrophages from adult mice inhibited virus replication in the muscle tissues of infected mice, and this was followed by a relief of symptoms and a significant reduction of mortality, which suggested that the adoptive transfer of macrophages from adult humans represents a potential strategy to treat EV71-infected patients.

  20. Early antibiotics and debridement independently reduce infection in an open fracture model.

    PubMed

    Penn-Barwell, J G; Murray, C K; Wenke, J C

    2012-01-01

    Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment. We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis. No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm.

  1. An Ensemble Method to Distinguish Bacteriophage Virion from Non-Virion Proteins Based on Protein Sequence Characteristics.

    PubMed

    Zhang, Lina; Zhang, Chengjin; Gao, Rui; Yang, Runtao

    2015-01-01

    Bacteriophage virion proteins and non-virion proteins have distinct functions in biological processes, such as specificity determination for host bacteria, bacteriophage replication and transcription. Accurate identification of bacteriophage virion proteins from bacteriophage protein sequences is significant to understand the complex virulence mechanism in host bacteria and the influence of bacteriophages on the development of antibacterial drugs. In this study, an ensemble method for bacteriophage virion protein prediction from bacteriophage protein sequences is put forward with hybrid feature spaces incorporating CTD (composition, transition and distribution), bi-profile Bayes, PseAAC (pseudo-amino acid composition) and PSSM (position-specific scoring matrix). When performing on the training dataset 10-fold cross-validation, the presented method achieves a satisfactory prediction result with a sensitivity of 0.870, a specificity of 0.830, an accuracy of 0.850 and Matthew's correlation coefficient (MCC) of 0.701, respectively. To evaluate the prediction performance objectively, an independent testing dataset is used to evaluate the proposed method. Encouragingly, our proposed method performs better than previous studies with a sensitivity of 0.853, a specificity of 0.815, an accuracy of 0.831 and MCC of 0.662 on the independent testing dataset. These results suggest that the proposed method can be a potential candidate for bacteriophage virion protein prediction, which may provide a useful tool to find novel antibacterial drugs and to understand the relationship between bacteriophage and host bacteria. For the convenience of the vast majority of experimental Int. J. Mol. Sci. 2015, 16,21735 scientists, a user-friendly and publicly-accessible web-server for the proposed ensemble method is established.

  2. An Ensemble Method to Distinguish Bacteriophage Virion from Non-Virion Proteins Based on Protein Sequence Characteristics

    PubMed Central

    Zhang, Lina; Zhang, Chengjin; Gao, Rui; Yang, Runtao

    2015-01-01

    Bacteriophage virion proteins and non-virion proteins have distinct functions in biological processes, such as specificity determination for host bacteria, bacteriophage replication and transcription. Accurate identification of bacteriophage virion proteins from bacteriophage protein sequences is significant to understand the complex virulence mechanism in host bacteria and the influence of bacteriophages on the development of antibacterial drugs. In this study, an ensemble method for bacteriophage virion protein prediction from bacteriophage protein sequences is put forward with hybrid feature spaces incorporating CTD (composition, transition and distribution), bi-profile Bayes, PseAAC (pseudo-amino acid composition) and PSSM (position-specific scoring matrix). When performing on the training dataset 10-fold cross-validation, the presented method achieves a satisfactory prediction result with a sensitivity of 0.870, a specificity of 0.830, an accuracy of 0.850 and Matthew’s correlation coefficient (MCC) of 0.701, respectively. To evaluate the prediction performance objectively, an independent testing dataset is used to evaluate the proposed method. Encouragingly, our proposed method performs better than previous studies with a sensitivity of 0.853, a specificity of 0.815, an accuracy of 0.831 and MCC of 0.662 on the independent testing dataset. These results suggest that the proposed method can be a potential candidate for bacteriophage virion protein prediction, which may provide a useful tool to find novel antibacterial drugs and to understand the relationship between bacteriophage and host bacteria. For the convenience of the vast majority of experimental scientists, a user-friendly and publicly-accessible web-server for the proposed ensemble method is established. PMID:26370987

  3. Orsay virus utilizes ribosomal frameshifting to express a novel protein that is incorporated into virions

    SciTech Connect

    Jiang, Hongbing; Franz, Carl J.; Wu, Guang; Renshaw, Hilary; Zhao, Guoyan; Firth, Andrew E.; Wang, David

    2014-02-15

    Orsay virus is the first identified virus that is capable of naturally infecting Caenorhabditis elegans. Although it is most closely related to nodaviruses, Orsay virus differs from nodaviruses in its genome organization. In particular, the Orsay virus RNA2 segment encodes a putative novel protein of unknown function, termed delta, which is absent from all known nodaviruses. Here we present evidence that Orsay virus utilizes a ribosomal frameshifting strategy to express a novel fusion protein from the viral capsid (alpha) and delta ORFs. Moreover, the fusion protein was detected in purified virus fractions, demonstrating that it is most likely incorporated into Orsay virions. Furthermore, N-terminal sequencing of both the fusion protein and the capsid protein demonstrated that these proteins must be translated from a non-canonical initiation site. While the function of the alpha–delta fusion remains cryptic, these studies provide novel insights into the fundamental properties of this new clade of viruses. - Highlights: • Orsay virus encodes a novel fusion protein by a ribosomal frameshifting mechanism. • Orsay capsid and fusion protein is translated from a non-canonical initiation site. • The fusion protein is likely incorporated into Orsay virions.

  4. Immunogenicity studies of bivalent inactivated virions of EV71/CVA16 formulated with submicron emulsion systems.

    PubMed

    Lin, Chih-Wei; Liu, Chia-Chyi; Lu, Tsung-Chun; Liu, Shih-Jen; Chow, Yen-Hung; Chong, Pele; Huang, Ming-Hsi

    2014-01-01

    We assessed two strategies for preparing candidate vaccines against hand, foot, and mouth disease (HFMD) caused mainly by infections of enterovirus (EV) 71 and coxsackievirus (CV) A16. We firstly design and optimize the potency of adjuvant combinations of emulsion-based delivery systems, using EV71 candidate vaccine as a model. We then perform immunogenicity studies in mice of EV71/CVA16 antigen combinations formulated with PELC/CpG. A single dose of inactivated EV71 virion (0.2 μg) emulsified in submicron particles was found (i) to induce potent antigen-specific neutralizing antibody responses and (ii) consistently to elicit broad antibody responses against EV71 neutralization epitopes. A single dose immunogenicity study of bivalent activated EV71/CVA16 virion formulated with either Alum or PELC/CpG adjuvant showed that CVA16 antigen failed to elicit CVA16 neutralizing antibody responses and did not affect EV71-specific neutralizing antibody responses. A boosting dose of emulsified EV71/CVA16 bivalent vaccine candidate was found to be necessary to achieve high seroconversion of CVA16-specific neutralizing antibody responses. The current results are important for the design and development of prophylactic vaccines against HFMD and other emerging infectious diseases.

  5. Growing steers grazing high versus low endophyte (Neotyphodium coenophialum)-infected tall fescue have reduced serum enzymes increased hepatic glucogenic enzymes and reduced liver and carcass mass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is well established that grazing Neotyphodium coenophialum-infected forages results in reduced weight gain and serum prolactin levels of cattle. The objective of this study was to determine the potential effects of toxic endophyte-infected tall fescue consumption on carcass characteristics, bloo...

  6. Upregulation of Cellular Bcl-2 by the KSHV Encoded RTA Promotes Virion Production

    PubMed Central

    Gao, Jianming; Cai, Qiliang; Lu, Jie; Jha, Hem Chandra; Robertson, Erle S.

    2011-01-01

    Apoptosis of virus infected cells can restrict or dampen full blown virus propagation and this can serve as a protective mechanism against virus infection. Consequently, viruses can also delay programmed cell death by enhancing the expression of anti-apoptotic proteins. Human Bcl-2 is expressed on the surface of the mitochondrial membrane and functions as the regulator of the delicate balance between cell survival and apoptosis. In this report, we showed that the replication and transcription activator (RTA) encoded by KSHV ORF 50, a key regulator for KSHV reactivation from latent to lytic infection, upregulates the mRNA and protein levels of Bcl-2 in 293 cells, and TPA-induced KSHV-infected cells. Further analysis revealed that upregulation of the cellular Bcl-2 promoter by RTA is dose-dependent and acts through targeting of the CCN9GG motifs within the Bcl-2 promoter. The Bcl-2 P2 but not the P1 promoter is primarily responsive to RTA. The results of ChIP confirmed the direct interaction of RTA protein with the CCN9GG motifs. Knockdown of cellular Bcl-2 by lentivirus-delivered small hairpin RNA (shRNA) resulted in increased cell apoptosis and decreased virion production in KSHV-infected cells. These findings provide an insight into another mechanism by which KSHV utilizes the intrinsic apoptosis signaling pathways for prolonging the survival of lytically infected host cells to allow for maximum production of virus progeny. PMID:21901143

  7. Enhancing Patient Safety by Reducing Healthcare-Associated Infections: The Role of Discovery and Dissemination

    PubMed Central

    2010-01-01

    Healthcare-associated infections (HAIs) take a major human toll on society and reduce public confidence in the healthcare system. The current convergence of scientific, public, and legislative interest in reducing rates of HAI can provide the necessary momentum to address and answer important questions in HAI research. This position paper outlines priorities for a national approach to HAIs: scrutinizing the science base, developing a prioritized research agenda, conducting studies that address the questions that have been identified, creating and deploying guidelines that are based on the outcomes of these studies, and then initiating new studies that assess the efficacy of the interventions. PMID:20038249

  8. [The correct use of the condom reduces the risk of HIV infection].

    PubMed

    Scala, E; Luzi, G; Aiuti, F

    1989-12-01

    In recent years the use of the condom has increased rapidly because of its potential to protect against AIDS. It has been particularly effective in combination with nonoxynol-9 (NP-9), which stopped the reproduction of HIV virus in 60 seconds in vitro. Benzalkonium chloride in .0% concentration also killed HIV in vaginal secretions. Epidemiological studies confirmed the efficacy of the condom to stop HIV infection. In an experiment involving 263 prostitutes in Nairobi, Kenya, 80% of them used condoms, and seroconversion diminished in direct relationship with the frequency of use. HIV infection was absent in 14 partners using the condom regularly for 2 years among 31 seropositive hemophiliacs, while 3 women (17%) of 17 couples not using it regularly got infected. In a study of 43 heterosexual couples (13 women and 30 men) where 1 partner was infected, 6 men and 16 women became seropositive after 4 years. Only 35% of the women used the condom. Heterosexual AIDS increased from 1% in 1985 to 6.8% in 1989, and a 60-year-old man became seropositive after repeated episodes of oral sex with a female seropositive prostitute. In Italy, seropositive inmates make up 15-18% of the prison population. The risk of transmission after sex with an infected person is .01%, but the condom can reduce this risk by 90%. A public education campaign in the US has boosted the sale of condoms by 22%. The risk of infection is 1 in 5 billion after a single sexual act with a low risk person; however, the risk of transmission was an extremely high 2 infections/3 cases when the condom was not used in 500 sexual acts with a seropositive person. 100 acts with a single seropositive person using the condom poses a much higher risk of infection than a single unprotected act with 100 partners who have a 1% risk of having the disease. Although the public campaign extolling the virtues of the condom may generate a sense of false security, the available evidence suggests that the condom provides a unique

  9. [Pathogenic Machupo and Lassa arenaviruses: the biochemical properties of virion RNA and proteins].

    PubMed

    Lukashevich, I S; Lemeshko, N N; Stel'makh, T A; Golubev, V P

    1987-01-01

    Lassa virus purified in the isodensity sucrose concentration gradient had the following buoyant densities: 1.17 g/cm3 (sucrose), 1.19 g/cm3 (cesium chloride), 1.16 g/cm3 (urografin). Similar parameters were obtained for Machupo virus. Virion RNAs of these viruses contained 5 sedimentation classes of molecules: 30-31S, 28S, 22-24S, 18S, and 4-6S. Experiments on hybridization of individual sedimentation classes of RNA with an excess of poly(A)-containing RNA from the infected cells as well as inhibition of synthesis of 28S and 18S virion RNAs with low concentrations (0.005-0.5 micrograms/ml) of actinomycin D showed the genetic information for virus proteins to be coded for in two segments: 30-31S and 22-24S. The method of self-annealing demonstrated molecules with complementary sequence ("plus" and "minus" strands) in genome RNAs. In addition to previously described major proteins (78K, 64K, 37K), high performance liquid gel-penetrating chromatography of Machupo virus structural proteins revealed a minor protein with molecular weight of 50 kilodaltons. Pulse-chase experiments demonstrated in the infected cells a precursor-product metabolic bond between glycosylated proteins 78K and 37K. Lassa virus contained 3 structural major proteins with molecular weights 60, 48, and 34 kilodaltons (K). The 60K protein was detected in the nucleocapsid fraction, and 48 K protein in the soluble subvirion fraction. Proteins 60K and 34K were immunoprecipitated in greatest amounts in the infected cells.

  10. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity.

    PubMed

    Eiri, Daren M; Suwannapong, Guntima; Endler, Matthew; Nieh, James C

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study.

  11. Moderate physical exercise reduces parasitaemia and protects colonic myenteric neurons in mice infected with Trypanosoma cruzi

    PubMed Central

    Moreira, Neide M; Santos, Franciele d N; Toledo, Max Jean d O; Moraes, Solange M F d; Araujo, Eduardo J d A; Sant'Ana, Debora d M G; Araujo, Silvana M d

    2013-01-01

    This study evaluated the influence of moderate physical exercise on the myenteric neurons in the colonic intestinal wall of mice that had been infected with Trypanosoma cruzi. Parasitology and immunological aspects of the mice were considered. Forty-day-old male Swiss mice were divided into four groups: Trained Infected (TI), Sedentary Infected (SI), Trained Control (TC), and Sedentary Control (SC). The TC and TI were subjected to a moderate physical exercise program on a treadmill for 8 weeks. Three days after finishing exercise, the TI and SI groups were inoculated with 1,300 blood trypomastigotes of the Y strain-T. cruzi. After 75 days of infection results were obtained. Kruskal-Wallis or Analyze of variance (Tukey post hoc test) at 5% level of significance was performed. Moderate physical exercise reduced both the parasite peak (day 8 of infection) and total parasitemia compared with the sedentary groups (P < 0.05). This activity also contributed to neuronal survival (P < 0.05). Exercise caused neuronal hypertrophy (P < 0.05) and an increase in the total thickness of the intestinal wall (P < 0.05). The TI group exhibited an increase in the number of intraepithelial lymphocytes (P > 0.05). In trained animals, the number of goblet cells was reduced compared with sedentary animals (P < 0.05). Physical exercise prevented the formation of inflammatory foci in the TI group (P < 0.05) and increased the synthesis of TNF-α (P < 0.05) and TGF-β (P > 0.05). The present results demonstrated the benefits of moderate physical exercise, and reaffirmed the possibility of that it may contribute to improving clinical treatment in Chagas' disease patients. PMID:24205797

  12. Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity

    PubMed Central

    Eiri, Daren M.; Suwannapong, Guntima; Endler, Matthew; Nieh, James C.

    2015-01-01

    Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage. We reared honey bee (Apis mellifera) larvae in vitro and provide the first demonstration that N. ceranae can infect larvae and decrease subsequent adult longevity. We exposed three-day-old larvae to a single dose of 40,000 (40K), 10,000 (10K), zero (control), or 40K autoclaved (control) N. ceranae spores in larval food. Spores developed intracellularly in midgut cells at the pre-pupal stage (8 days after egg hatching) of 41% of bees exposed as larvae. We counted the number of N. ceranae spores in dissected bee midguts of pre-pupae and, in a separate group, upon adult death. Pre-pupae exposed to the 10K or 40K spore treatments as larvae had significantly elevated spore counts as compared to controls. Adults exposed as larvae had significantly elevated spore counts as compared to controls. Larval spore exposure decreased longevity: a 40K treatment decreased the age by which 75% of adult bees died by 28%. Unexpectedly, the low dose (10K) led to significantly greater infection (1.3 fold more spores and 1.5 fold more infected bees) than the high dose (40K) upon adult death. Differential immune activation may be involved if the higher dose triggered a stronger larval immune response that resulted in fewer adult spores but imposed a cost, reducing lifespan. The impact of N. ceranae on honey bee larval development and the larvae of naturally infected colonies therefore deserve further study. PMID:26018139

  13. Does Heparin Coating Improve Patency or Reduce Infection of Tunneled Dialysis Catheters?

    PubMed Central

    Jain, Gaurav; Allon, Michael; Saddekni, Souheil; Barker, Jill-Finkel

    2009-01-01

    Background and objectives: Tunneled dialysis catheters are prone to frequent malfunction and infection. Catheter thrombosis occurs despite prophylactic anticoagulant locks. Catheter thrombi may also serve as a nidus for catheter infection, thereby increasing the risk of bacteremia. Thus, heparin coating of catheters may reduce thrombosis and infection. This study evaluated whether heparin-coated hemodialysis catheters have fewer infections or greater cumulative survival than noncoated catheters. Design, setting, participants, & measurements: We retrospectively queried a prospective access database to analyze the outcomes of 175 tunneled dialysis catheters placed in the internal jugular vein, including 89 heparin-coated catheters and 86 noncoated catheters. The primary outcome was cumulative catheter survival, and the secondary outcome was infection-free catheter survival. Results: The two patient groups were similar in demographics and clinical and catheter features. Catheter-related bacteremia occurred less frequently with heparin-coated catheters than with noncoated catheters (34 versus 60%, P < 0.001). Cumulative catheter survival was similar in heparin-coated and noncoated catheters (hazard ratio, 0.87; 95% confidence interval, 0.55 to 1.36; P = 0.53). On multiple variable survival analysis including catheter type, age, sex, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, catheter location, and previous catheter, only catheter location predicted cumulative catheter survival (hazard ratio, 2.03; 95% CI, 1.27 to 3.25, with the right internal jugular location being the reference group, P = 0.003). The frequency of thrombolytic instillation was 1.8 per 1000 catheter-days in both groups. Conclusions: Heparin coating decreases the frequency of catheter-related bacteremia but does not reduce the frequency of catheter malfunction. PMID:19729425

  14. Reduced central line infection rates in children with leukemia following caregiver training

    PubMed Central

    Lo Vecchio, Andrea; Schaffzin, Joshua K.; Ruberto, Eliana; Caiazzo, Maria Angela; Saggiomo, Loredana; Mambretti, Daniela; Russo, Danila; Crispo, Sara; Continisio, Grazia Isabella; Dello Iacovo, Rossano; Poggi, Vincenzo; Guarino, Alfredo

    2016-01-01

    Abstract Infections are a leading cause of morbidity and mortality in children with acute leukemia. Central-line (CL) devices increase this population's risk of serious infections. Within the context of a quality improvement (QI) project, we tested the effect of caregiver education on CL management on the CL-associated bloodstream infection (CLABSI) rate among children with acute leukemia seen at a large referral center in Italy. The intervention consisted of 9 in-person sessions for education and practice using mannequins and children. One hundred and twenty caregivers agreed to participate in the initiative. One hundred and five (87.5%) completed the training, 5 (4.1%) withdrew after the first session, and 10 (8.3%) withdrew during practical sessions. After educational intervention, the overall CLABSI rate was reduced by 46% (from 6.86 to 3.70/1000 CL-days). CLABSI rate was lower in children whose caregivers completed the training (1.74/1000 CL-days, 95% CI 0.43–6.94) compared with those who did not receive any training (12.2/1000 CL-days, 95% CI 7.08–21.0, P < 0.05) or were in-training (3.96/1000 CL-days, 95% CI 1.98–7.91) at the time of infection. Caregiver training in CL management, applied within a multifaceted QI approach, reduced the rate of CLABSI in children with acute leukemia. Specific training and active involvement of caregivers in CL management may be effective to reduce CLABSI in high-risk children. PMID:27336888

  15. Vaccinia virions deficient in transcription enzymes lack a nucleocapsid

    SciTech Connect

    McFadden, Baron D.H.; Moussatche, Nissin; Kelley, Karen; Kang, Byung-Ho; Condit, Richard C.

    2012-12-05

    The poxvirus virion contains an inner tubular nucleocapsid structure. The nucleocapsid is apparently labile to conventional electron microscopy fixation procedures and has therefore been largely ignored for decades. Advancements in electron microscopy sample preparation, notably high pressure freezing, better preserve the nucleocapsid structure. Using high pressure freezing and electron microscopy, we have compared the virion structures of wt virus and mutant viruses known to be deficient in packaging of viral transcription enzymes. We show that the mutant viruses lack a defined nucleocapsid. These results support the hypothesis that the nucleocapsid contains the viral DNA genome complexed with viral transcription enzymes and structural proteins. The studies open the door to further investigation of the composition and ultrastructure of the poxvirus nucleocapsid.

  16. Nurse-driven quality improvement interventions to reduce hospital-acquired infection in the NICU.

    PubMed

    Ceballos, Kirtley; Waterman, Kari; Hulett, Teresa; Makic, Mary Beth Flynn

    2013-06-01

    Hospital-acquired infections are a leading cause of morbidity and mortality in neonatal intensive care units. Central line-associated blood stream infection (CLABSI) and ventilator-associated pneumonia (VAP) are costly, preventable infections targeted for eradication by the Centers for Disease Control and Prevention. After evaluation of current practice and areas for improvement, neonatal-specific CLABSI and VAP bundles were developed and implemented on the basis of available best evidence. The overall goal was to reduce infection rates at or below benchmarks set by National Healthcare Safety Network. All neonates with central lines (umbilical or percutaneous) and/or patients who were endotracheally intubated were included. All patients were risk stratified on the basis of weight per National Healthcare Safety Network reporting requirements: less than 750 g, 751-1000 g, 1001-1500 g, 1501-2500 g, and greater than 2500 g. The research was conducted as a quality improvement study. Neonatal-specific educational modules were developed by neonatal nurse leaders for CLABSI and VAP. Bundle development entailed combining select interventions, mainly from the adult literature, that the nurse leaders believed would reduce infection rates. Nursing practice guidelines and supply carts were updated to ensure understanding, compliance, and convenience. A CLABSI checklist was initiated and used at the time of line insertion by the nurse to ensure standardized infection control practices. Compliance audits were performed by nurse leaders weekly on intubated patients to validate VAP bundle implementation. CLABSI and VAP bundle compliance was audited and infection rates were measured before and after both bundle implementations following strict National Healthcare Safety Network inclusion criteria for CLABSI and VAP determination. The reduction in CLABSI elicited 84 fewer hospital days, estimated cost savings of $348,000, a 92% reduction in CLABSI (preintervention to postintervention

  17. Symptomatic and Asymptomatic Campylobacter Infections Associated with Reduced Growth in Peruvian Children

    PubMed Central

    Lee, Gwenyth; Pan, William; Peñataro Yori, Pablo; Paredes Olortegui, Maribel; Tilley, Drake; Gregory, Michael; Oberhelman, Richard; Burga, Rosa; Chavez, Cesar Banda; Kosek, Margaret

    2013-01-01

    Background Although diarrheal illnesses are recognized as both a cause and effect of undernutrition, evidence for the effect of specific enteropathogens on early childhood growth remains limited. We estimated the effects of undernutrition as a risk factor for campylobacteriosis, as well as associations between symptomatic and asymptomatic Campylobacter infections and growth. Methodology/Principal Findings Using data from a prospective cohort of 442 children aged 0–72 months, the effect of nutritional status on the incidence of Campylobacter infection was estimated using uni- and multivariate Poisson models. Multivariate regression models were developed to evaluate the effect of Campylobacter infection on weight gain and linear growth. Overall, 8.3% of diarrheal episodes were associated with Campylobacter (crude incidence rate = 0.37 episodes/year) and 4.9% of quarterly asymptomatic samples were Campylobacter positive. In univariate models, the incidence of Campylobacter infection was marginally higher in stunted than non-stunted children (IRR 1.270, 95% CI (0.960, 1.681)(p = 0.095). When recent diarrheal burdens were included in the analysis, there was no difference in risk between stunted and unstunted children. Asymptomatic and symptomatic Campylobacter infections were associated with reduced weight gain over a three-month period (65.5 g (95% CI: −128.0, −3.0)(p = 0.040) and 43.9 g (95% CI:−87.6, −1.0)(p = 0.049) less weight gain, respectively). Symptomatic Campylobacter infections were only marginally associated with reduced linear growth over a nine month period (−0.059 cm per episode, 95% CI: −0.118, 0.001)(p = 0.054), however relatively severe episodes were associated with reduced linear growth (−0.169 cm/episode, 95% CI −0.310, −0.028)(p = 0.019). Conclusions/Significance Our findings suggest that Campylobacter is not as benign as commonly assumed, and that there is evidence to support expanding the indications for

  18. Interactions of peptide triazole thiols with Env gp120 induce irreversible breakdown and inactivation of HIV-1 virions

    PubMed Central

    2013-01-01

    Background We examined the underlying mechanism of action of the peptide triazole thiol, KR13 that has been shown previously to specifically bind gp120, block cell receptor site interactions and potently inhibit HIV-1 infectivity. Results KR13, the sulfhydryl blocked KR13b and its parent non-sulfhydryl peptide triazole, HNG156, induced gp120 shedding but only KR13 induced p24 capsid protein release. The resulting virion post virolysis had an altered morphology, contained no gp120, but retained gp41 that bound to neutralizing gp41 antibodies. Remarkably, HIV-1 p24 release by KR13 was inhibited by enfuvirtide, which blocks formation of the gp41 6-helix bundle during membrane fusion, while no inhibition of p24 release occurred for enfuvirtide-resistant virus. KR13 thus appears to induce structural changes in gp41 normally associated with membrane fusion and cell entry. The HIV-1 p24 release induced by KR13 was observed in several clades of HIV-1 as well as in fully infectious HIV-1 virions. Conclusions The antiviral activity of KR13 and its ability to inactivate virions prior to target cell engagement suggest that peptide triazole thiols could be highly effective in inhibiting HIV transmission across mucosal barriers and provide a novel probe to understand biochemical signals within envelope that are involved in membrane fusion. PMID:24330857

  19. Extraintestinal helminth infection reduces the development of colitis-associated tumorigenesis.

    PubMed

    León-Cabrera, Sonia; Callejas, Blanca E; Ledesma-Soto, Yadira; Coronel, Jossimar; Pérez-Plasencia, Carlos; Gutiérrez-Cirlos, Emma B; Ávila-Moreno, Federico; Rodríguez-Sosa, Miriam; Hernández-Pando, Rogelio; Marquina-Castillo, Brenda; Chirino, Yolanda I; Terrazas, Luis I

    2014-01-01

    Colitis-associated colorectal cancer (CAC) is one of the most common cancers and is closely related to chronic or deregulated inflammation. Helminthic infections can modulate inflammatory responses in some diseases, but their immunomodulatory role during cancer development remains completely unknown. We have analyzed the role of Taenia crassiceps-induced anti-inflammatory response in determining the outcome of CAC. We show that extraintestinal T. crassiceps infection in CAC mice inhibited colonic inflammatory responses and tumor formation and prevented goblet cell loss. There was also increased expression of IL-4 and alternatively activated macrophages markers in colonic tissue and negative immunomodulation of pro-inflammatory cytokine expression. In addition, T. crassiceps infection prevented the upregulation of β-catenin and CXCR2 expression observed in the CAC mice, which are both markers associated with CAC-tumorigenesis, and reduced the numbers of circulating and colonic CD11b(+)Ly6C(hi)CCR2(+) monocytes. Thus, immunomodulatory activities induced by helminth infections may have a role in the progression of CAC.

  20. Treatment outcomes for serious infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility.

    PubMed

    Howden, Benjamin P; Ward, Peter B; Charles, Patrick G P; Korman, Tony M; Fuller, Andrew; du Cros, Philipp; Grabsch, Elizabeth A; Roberts, Sally A; Robson, Jenny; Read, Kerry; Bak, Narin; Hurley, James; Johnson, Paul D R; Morris, Arthur J; Mayall, Barrie C; Grayson, M Lindsay

    2004-02-15

    Although infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility (SA-RVS) have been reported from a number of countries, including Australia, the optimal therapy is unknown. We reviewed the clinical features, therapy, and outcome of 25 patients with serious infections due to SA-RVS in Australia and New Zealand. Eight patients had endocarditis, 9 had bacteremia associated with deep-seated infection, 6 had osteomyelitis or septic arthritis, and 2 had empyema. All patients had received vancomycin before the isolation of SA-RVS, and glycopeptide treatment had failed for 19 patients (76%). Twenty-one patients subsequently received active treatment, which was effective for 16 patients (76%). Eighteen patients received linezolid, which was effective in 14 (78%), including 4 patients with endocarditis. Twelve patients received a combination of rifampicin and fusidic acid. Surgical intervention was required for 15 patients (60%). Antibiotic therapy, especially linezolid with or without rifampicin and fusidic acid, in conjunction with surgical debulking is effective therapy for the majority of patients with serious infections (including endocarditis) caused by SA-RVS.

  1. Toxoplasma gondii infection induces dendritic retraction in basolateral amygdala accompanied by reduced corticosterone secretion

    PubMed Central

    Mitra, Rupshi; Sapolsky, Robert Morris; Vyas, Ajai

    2013-01-01

    SUMMARY Pathological anxiety is thought to reflect a maladaptive state characterized by exaggerated fear. Naturally occurring perturbations that reduce fear can be crucial in the search for new treatments. The protozoan parasite Toxoplasma gondii invades rat brain and removes the fear that rats have of cat odors, a change believed to be parasitic manipulation of host behavior aimed at increasing parasite transmission. It is likely that mechanisms employed by T. gondii can be used as a heuristic tool to understand possible means of fear reduction in clinical settings. Male Long-Evans rats were infected with T. gondii and compared with sham-infected animals 8 weeks after infection. The amount of circulating plasma corticosterone and dendritic arborization of basolateral amygdala principal neurons were quantified. Previous studies have shown that corticosterone, acting within the basolateral amygdala, enhances the fear response to environmental stimuli. Here we show that T. gondii infection causes a dendritic retraction in basolateral amygdala neurons. Such dendritic retraction is accompanied by lower amounts of circulating corticosterone, both at baseline and when induced by an aversive cat odor. The concerted effects of parasitism on two pivotal physiological nodes of the fear response provide an animal model relevant to interactions between stress hormones and amygdalar plasticity. PMID:23104989

  2. Ultraviolet-ozone treatment reduces levels of disease-associated prion protein and prion infectivity

    USGS Publications Warehouse

    Johnson, C.J.; Gilbert, P.; McKenzie, D.; Pedersen, J.A.; Aiken, Judd M.

    2009-01-01

    Background. Transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative diseases caused by novel infectious agents referred to as prions. Prions appear to be composed primarily, if not exclusively, of a misfolded isoform of the cellular prion protein. TSE infectivity is remarkably stable and can resist many aggressive decontamination procedures, increasing human, livestock and wildlife exposure to TSEs. Findings. We tested the hypothesis that UV-ozone treatment reduces levels of the pathogenic prion protein and inactivates the infectious agent. We found that UV-ozone treatment decreased the carbon and prion protein content in infected brain homogenate to levels undetectable by dry-ashing carbon analysis or immunoblotting, respectively. After 8 weeks of ashing, UV-ozone treatment reduced the infectious titer of treated material by a factor of at least 105. A small amount of infectivity, however, persisted despite UV-ozone treatment. When bound to either montmorillonite clay or quartz surfaces, PrPTSE was still susceptible to degradation by UV-ozone. Conclusion. Our findings strongly suggest that UV-ozone treatment can degrade pathogenic prion protein and inactivate prions, even when the agent is associated with surfaces. Using larger UV-ozone doses or combining UV-ozone treatment with other decontaminant methods may allow the sterilization of TSE-contaminated materials. ?? 2009 Aiken et al; licensee BioMed Central Ltd.

  3. Protein Composition of the Vaccinia Virus Mature Virion

    SciTech Connect

    Resch, Wolfgang; Hixson, Kim K.; Moore, Ronald J.; Lipton, Mary S.; Moss, Bernard

    2007-02-05

    The protein content of vaccinia virus mature virions, purified by rate zonal and isopycnic centrifugation and solubilized by SDS or a solution of urea and thiourea, was determined by the accurate mass and time tag technology which uses both tandem mass spectrometry and Fourier transform-ion cyclotron resonance mass spectrometry to detect tryptic peptides separated by high-resolution liquid chromatography. Eighty vaccinia virus-encoded proteins representing 37% of the 218 genes annotated in the complete genome sequence were detected in at least three analyses. Ten proteins accounted for approximately 80% of the mass, while the least abundant proteins made up 1% or less of the mass. Thirteen identified proteins were not previously reported as components of virions. On the other hand, 8 previously described virion proteins were not detected here, presumably due to technical reasons including small size and hydrophobicity. In addition to vaccinia virus-encoded proteins, 24 host proteins omitting isoforms were detected. The most abundant of these were cytoskeletal proteins, heat shock proteins, and proteins involved in translation.

  4. Topical Nanoemulsion Therapy Reduces Bacterial Wound Infection and Inflammation Following Burn Injury

    PubMed Central

    Hemmila, Mark R.; Mattar, Aladdein; Taddonio, Michael A.; Arbabi, Saman; Hamouda, Tarek; Ward, Peter A.; Wang, Stewart C.; Baker, James R.

    2010-01-01

    Background Nanoemulsions are broadly antimicrobial oil-in-water emulsions containing nanometer-sized droplets stabilized with surfactants. We hypothesize that topical application of a nanoemulsion compound (NB-201) can attenuate burn wound infection. In addition to reducing infection, nanoemulsion therapy may modulate dermal inflammatory signaling and thereby lessen inflammation following thermal injury. Methods Male Sprague-Dawley rats underwent a 20% total body surface area (TBSA) scald burn to create a partial thickness burn injury. Animals were resuscitated with Ringer’s lactate and the wound covered with an occlusive dressing. Eight hours after injury, the burn wound was inoculated with 1×106 CFU of Pseudomonas aeruginosa. NB-201, NB-201 placebo, 5% mafenide acetate solution or 0.9% saline (control) was applied onto the wound at 16 and 24 hrs following burn injury. Skin was harvested 32 hrs post-burn for quantitative wound culture and determination of inflammatory mediators in tissue homogenates. Results NB-201 reduced mean bacterial growth in the burn wound by a thousand fold, with only 11% animals having P. aeruginosa counts greater than 105 CFU/g tissue versus 91% in the control group (p<0.0001). Treatment with NB-201 attenuated neutrophil sequestration in the treatment group as measured by myeloperoxidase assay and by histology. It also, significantly reduced levels of pro-inflammatory cytokines (IL-1β and IL-6) and the degree of hair follicle cell apoptosis in skin when compared to saline-treated controls. Conclusions Topical NB-201 substantially reduced bacterial growth in a partial thickness burn model. This reduction in the level of wound infection was associated with an attenuation of the local dermal inflammatory response and diminished neutrophil sequestration. NB-201 represents a novel potent antimicrobial and antiinflammatory treatment for use in burn wounds. PMID:20189619

  5. Reducing infection in chronic leg ulcers with an activated carbon cloth dressing.

    PubMed

    Murphy, Nina

    2016-06-23

    Zorflex is a new type of antimicrobial dressing composed of 100% activated carbon cloth. It attracts and binds bacteria to its surface, enabling them to be safely removed at dressing change. It has no reported toxic effects and can be used on either a short-or long-term basis. This article describes 4 case studies in which patients with recalcitrant chronic venous leg ulcers that were prone to recurrent infection were treated with the activated carbon cloth dressing. All of the wounds had failed to respond to antimicrobial dressings containing silver, iodine or polyhexamethylene biguanide (PHMB), and were heavily exuding and painful. In all cases, the signs of infection reduced significantly within 4 weeks, resulting in good patient outcomes. PMID:27345081

  6. Honey and green/black tea consumption may reduce the risk of Helicobacter pylori infection.

    PubMed

    Boyanova, Lyudmila; Ilieva, Juliana; Gergova, Galina; Vladimirov, Borislav; Nikolov, Rossen; Mitov, Ivan

    2015-05-01

    The aim of the study was to evaluate the influence of dietary and demographic factors and some habits on the prevalence of Helicobacter pylori infection in 150 dyspeptic patients examined endoscopically and by the urea breath test. Positivity rate was lower (50.6%) in patients consuming honey ≥1 day weekly compared with the remainder (70.8%) and in those consuming green/black tea ≥1 day weekly (45.2%) compared with the other patients (64.8%). Logistic regression confirmed that the factors associated with significantly lower H. pylori positivity rate were the consumption of honey (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.19-0.78) and green/black tea (OR, 0.45; 95% CI, 0.21-0.95). In conclusion, honey and green/black tea intake is associated with reduced prevalence of H. pylori infection.

  7. Immunotherapy of HIV-infected patients with Gc protein-derived macrophage activating factor (GcMAF).

    PubMed

    Yamamoto, Nobuto; Ushijima, Naofumi; Koga, Yoshihiko

    2009-01-01

    Serum Gc protein (known as vitamin D3-binding protein) is the precursor for the principal macrophage activating factor (MAF). The MAF precursor activity of serum Gc protein of HIV-infected patients was lost or reduced because Gc protein is deglycosylated by alpha-N-acetylgalactosaminidase (Nagalase) secreted from HIV-infected cells. Therefore, macrophages of HIV-infected patients having deglycosylated Gc protein cannot be activated, leading to immunosuppression. Since Nagalase is the intrinsic component of the envelope protein gp120, serum Nagalase activity is the sum of enzyme activities carried by both HIV virions and envelope proteins. These Nagalase carriers were already complexed with anti-HIV immunoglobulin G (IgG) but retained Nagalase activity that is required for infectivity. Stepwise treatment of purified Gc protein with immobilized beta-galactosidase and sialidase generated the most potent macrophage activating factor (termed GcMAF), which produces no side effects in humans. Macrophages activated by administration of 100 ng GcMAF develop a large amount of Fc-receptors as well as an enormous variation of receptors that recognize IgG-bound and unbound HIV virions. Since latently HIV-infected cells are unstable and constantly release HIV virions, the activated macrophages rapidly intercept the released HIV virions to prevent reinfection resulting in exhaustion of infected cells. After less than 18 weekly administrations of 100 ng GcMAF for nonanemic patients, they exhibited low serum Nagalase activities equivalent to healthy controls, indicating eradication of HIV-infection, which was also confirmed by no infectious center formation by provirus inducing agent-treated patient PBMCs. No recurrence occurred and their healthy CD + cell counts were maintained for 7 years. PMID:19031451

  8. Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae

    PubMed Central

    da Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Uriostegui, Miguel Angel Mercado; Reyes, Manuela; Soares, Filippe Elias de Freitas; de Carvalho, Lorendane Millena; Rodrigues, Francielle Bosi; de Araújo, Jackson Victor

    2015-01-01

    The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 106. Group 4 received the combination of 5 × 106 D. flagrans chlamydospores + 5 × 106 C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species. PMID:26504809

  9. Efficacy of Clonostachys rosea and Duddingtonia flagrans in Reducing the Haemonchus contortus Infective Larvae.

    PubMed

    da Silva, Manoel Eduardo; Braga, Fabio Ribeiro; de Gives, Pedro Mendoza; Uriostegui, Miguel Angel Mercado; Reyes, Manuela; Soares, Filippe Elias de Freitas; de Carvalho, Lorendane Millena; Rodrigues, Francielle Bosi; de Araújo, Jackson Victor

    2015-01-01

    The biocontrol is proven effective in reducing in vitro and in situ free-living stages of major gastrointestinal helminths, allowing progress in reducing losses by parasitism, maximizing production, and productivity. This study aimed at evaluating the predatory activity of fungal isolates of Duddingtonia flagrans and Clonostachys rosea species and its association on infective larvae (L3) of H. contortus in microplots formed by grasses and maintained in a protected environment. All groups were added with 10 mL of an aqueous suspension with 618 H. contortus L3 approximately. Group 1 was used as control and only received the infective larvae. Groups 2 and 3 received D. flagrans chlamydospores and C. rosea conidia at doses of 5 × 10(6). Group 4 received the combination of 5 × 10(6) D. flagrans chlamydospores + 5 × 10(6) C. rosea conidia. D. flagrans and C. rosea showed nematicidal effectiveness reducing by 91.5 and 88.9%, respectively, the population of H. contortus L3. However, when used in combination efficiency decreased to 74.5% predation of H. contortus L3. These results demonstrate the need for further studies to determine the existence of additive effects, synergistic or antagonistic, between these species.

  10. PPARγ Agonists as an Anti-Inflammatory Treatment Inhibiting Rotavirus Infection of Small Intestinal Villi

    PubMed Central

    Gómez, Dory; Muñoz, Natalia; Guerrero, Rafael; Acosta, Orlando; Guerrero, Carlos A.

    2016-01-01

    Rotavirus infection has been reported to induce an inflammatory response in the host cell accompanied by the increased expression or activation of some cellular molecules including ROS, NF-κB, and COX-2. PPARγ stimulation and N-acetylcysteine (NAC) treatment have been found to interfere with viral infections including rotavirus infection. Small intestinal villi isolated from in vivo infected mice with rotavirus ECwt were analyzed for the percentage of ECwt-infected cells, the presence of rotavirus antigens, and infectious virion yield following treatment with pioglitazone. Isolated villi were also infected in vitro and treated with PPARγ agonists (PGZ, TZD, RGZ, DHA, and ALA), all-trans retinoic acid (ATRA), and NAC. After treatments, the expression of cellular proteins including PPARγ, NF-κB, PDI, Hsc70, and COX-2 was analyzed using immunochemistry, ELISA, immunofluorescence, and Western blotting. The results showed that rotavirus infection led to an increased accumulation of the cellular proteins studied and ROS. The virus infection-induced accumulation of the cellular proteins studied and ROS was reduced upon pioglitazone treatment, causing also a concomitant reduction of the infectious virion yield. We hypothesized that rotavirus infection is benefiting from the induction of a host cell proinflammatory response and that the interference of the inflammatory pathways involved leads to decreased infection. PMID:27382365

  11. PPARγ Agonists as an Anti-Inflammatory Treatment Inhibiting Rotavirus Infection of Small Intestinal Villi.

    PubMed

    Gómez, Dory; Muñoz, Natalia; Guerrero, Rafael; Acosta, Orlando; Guerrero, Carlos A

    2016-01-01

    Rotavirus infection has been reported to induce an inflammatory response in the host cell accompanied by the increased expression or activation of some cellular molecules including ROS, NF-κB, and COX-2. PPARγ stimulation and N-acetylcysteine (NAC) treatment have been found to interfere with viral infections including rotavirus infection. Small intestinal villi isolated from in vivo infected mice with rotavirus ECwt were analyzed for the percentage of ECwt-infected cells, the presence of rotavirus antigens, and infectious virion yield following treatment with pioglitazone. Isolated villi were also infected in vitro and treated with PPARγ agonists (PGZ, TZD, RGZ, DHA, and ALA), all-trans retinoic acid (ATRA), and NAC. After treatments, the expression of cellular proteins including PPARγ, NF-κB, PDI, Hsc70, and COX-2 was analyzed using immunochemistry, ELISA, immunofluorescence, and Western blotting. The results showed that rotavirus infection led to an increased accumulation of the cellular proteins studied and ROS. The virus infection-induced accumulation of the cellular proteins studied and ROS was reduced upon pioglitazone treatment, causing also a concomitant reduction of the infectious virion yield. We hypothesized that rotavirus infection is benefiting from the induction of a host cell proinflammatory response and that the interference of the inflammatory pathways involved leads to decreased infection. PMID:27382365

  12. High Dietary Folate in Mice Alters Immune Response and Reduces Survival after Malarial Infection

    PubMed Central

    Meadows, Danielle N.; Bahous, Renata H.; Best, Ana F.; Rozen, Rima

    2015-01-01

    Malaria is a significant global health issue, with nearly 200 million cases in 2013 alone. Parasites obtain folate from the host or synthesize it de novo. Folate consumption has increased in many populations, prompting concerns regarding potential deleterious consequences of higher intake. The impact of high dietary folate on the host’s immune function and response to malaria has not been examined. Our goal was to determine whether high dietary folate would affect response to malarial infection in a murine model of cerebral malaria. Mice were fed control diets (CD, recommended folate level for rodents) or folic acid-supplemented diets (FASD, 10x recommended level) for 5 weeks before infection with Plasmodium berghei ANKA. Survival, parasitemia, numbers of immune cells and other infection parameters were assessed. FASD mice had reduced survival (p<0.01, Cox proportional hazards) and higher parasitemia (p< 0.01, joint model of parasitemia and survival) compared with CD mice. FASD mice had lower numbers of splenocytes, total T cells, and lower numbers of specific T and NK cell sub-populations, compared with CD mice (p<0.05, linear mixed effects). Increased brain TNFα immunoreactive protein (p<0.01, t-test) and increased liver Abca1 mRNA (p<0.01, t-test), a modulator of TNFα, were observed in FASD mice; these variables correlated positively (rs = 0.63, p = 0.01). Bcl-xl/Bak mRNA was increased in liver of FASD mice (p<0.01, t-test), suggesting reduced apoptotic potential. We conclude that high dietary folate increases parasite replication, disturbs the immune response and reduces resistance to malaria in mice. These findings have relevance for malaria-endemic regions, when considering anti-folate anti-malarials, food fortification or vitamin supplementation programs. PMID:26599510

  13. BCG vaccination reduces risk of tuberculosis infection in vaccinated badgers and unvaccinated badger cubs.

    PubMed

    Carter, Stephen P; Chambers, Mark A; Rushton, Stephen P; Shirley, Mark D F; Schuchert, Pia; Pietravalle, Stéphane; Murray, Alistair; Rogers, Fiona; Gettinby, George; Smith, Graham C; Delahay, Richard J; Hewinson, R Glyn; McDonald, Robbie A

    2012-01-01

    Wildlife is a global source of endemic and emerging infectious diseases. The control of tuberculosis (TB) in cattle in Britain and Ireland is hindered by persistent infection in wild badgers (Meles meles). Vaccination with Bacillus Calmette-Guérin (BCG) has been shown to reduce the severity and progression of experimentally induced TB in captive badgers. Analysis of data from a four-year clinical field study, conducted at the social group level, suggested a similar, direct protective effect of BCG in a wild badger population. Here we present new evidence from the same study identifying both a direct beneficial effect of vaccination in individual badgers and an indirect protective effect in unvaccinated cubs. We show that intramuscular injection of BCG reduced by 76% (Odds ratio = 0.24, 95% confidence interval (CI) 0.11-0.52) the risk of free-living vaccinated individuals testing positive to a diagnostic test combination to detect progressive infection. A more sensitive panel of tests for the detection of infection per se identified a reduction of 54% (Odds ratio = 0.46, 95% CI 0.26-0.88) in the risk of a positive result following vaccination. In addition, we show the risk of unvaccinated badger cubs, but not adults, testing positive to an even more sensitive panel of diagnostic tests decreased significantly as the proportion of vaccinated individuals in their social group increased (Odds ratio = 0.08, 95% CI 0.01-0.76; P = 0.03). When more than a third of their social group had been vaccinated, the risk to unvaccinated cubs was reduced by 79% (Odds ratio = 0.21, 95% CI 0.05-0.81; P = 0.02).

  14. Immunisation against a serine protease inhibitor reduces intensity of Plasmodium berghei infection in mosquitoes.

    PubMed

    Williams, Andrew R; Zakutansky, Sara E; Miura, Kazutoyo; Dicks, Matthew D J; Churcher, Thomas S; Jewell, Kerry E; Vaughan, Aisling M; Turner, Alison V; Kapulu, Melissa C; Michel, Kristin; Long, Carole A; Sinden, Robert E; Hill, Adrian V S; Draper, Simon J; Biswas, Sumi

    2013-10-01

    The mosquito innate immune response is able to clear the majority of Plasmodium parasites. This immune clearance is controlled by a number of regulatory molecules including serine protease inhibitors (serpins). To determine whether such molecules could represent a novel target for a malaria transmission-blocking vaccine, we vaccinated mice with Anopheles gambiae serpin-2. Antibodies against Anopheles gambiae serpin-2 significantly reduced the infection of a heterologous Anopheles species (Anopheles stephensi) by Plasmodium berghei, however this effect was not observed with Plasmodium falciparum. Therefore, this approach of targeting regulatory molecules of the mosquito immune system may represent a novel approach to transmission-blocking malaria vaccines.

  15. Effectiveness of interventions in reducing antibiotic use for upper respiratory infections in ambulatory care practices.

    PubMed

    Vinnard, Christopher; Linkin, Darren R; Localio, A Russell; Leonard, Charles E; Teal, Valerie L; Fishman, Neil O; Hennessy, Sean

    2013-02-01

    The objective was to evaluate the effect of separate interventions on antimicrobial prescribing for uncomplicated upper respiratory tract infections. The authors conducted a quasi-experimental pre-post study with concurrent control groups for each intervention. Academic detailing led to a significant reduction in unnecessary antibiotic prescribing. However, there was no significant change in antibiotic prescribing in response to educational mailings to providers or to provider involvement in patient mailings. Organizations that seek to reduce inappropriate use of antibiotics should use proven approaches, even when they are more expensive.

  16. Development of a hybrid simulation course to reduce central line infections.

    PubMed

    Clapper, Timothy

    2012-05-01

    Clinical educators are continually looking at ways to effectively deliver large amounts of information to their learners. Whether as a part of pre-course work or as a separate phase of training, there are numerous benefits to making information available to learners before conducting sessions that allow the learners to practice the skills. Hybrid courses consist of a mixture of online and on-site instruction and offer a viable option for clinical educators to consider, especially when their intended audience consists of thousands of learners. This article describes the experiences of a medical simulation center and the use of a hybrid curriculum technique to reduce central line infections.

  17. Enterovirus 71 Virion-Associated Galectin-1 Facilitates Viral Replication and Stability

    PubMed Central

    Lee, Pei-Huan; Liu, Chia-Ming; Ho, Tzong-Shiann; Tsai, Yi-Che; Lin, Chi-Cheng; Wang, Ya-Fang; Chen, Yuh-Ling; Yu, Chun-Keung; Wang, Shih-Min; Liu, Ching-Chuan; Shiau, Ai-Li; Lei, Huan-Yao; Chang, Chih-Peng

    2015-01-01

    Enterovirus 71 (EV71) infection causes a myriad of diseases from mild hand-foot-and-mouth disease or herpangina to fatal brain stem encephalitis complicated with pulmonary edema. Several severe EV71 endemics have occurred in Asia-Pacific region, including Taiwan, and have become a serious threat to children’s health. EV71 infection is initiated by the attachment of the virion to the target cell surface. Although this process relies primarily upon interaction between viruses and cell surface receptors, soluble factors may also influence the binding of EV71 to host cells.Galectin-1 has been reported to participate in several virus infections, but is not addressed in EV71. In this study, we found that the serum levels of galectin-1 in EV71-infected children were higher than those in non-infected people. In EV71 infected cells, galectin-1 was found to be associated with the EV71 VP1 and VP3 via carbohydrate residues and subsequently released and bound to another cell surface along with the virus. EV71 propagated from galectin-1 knockdown SK-N-SH cells exhibited lower infectivity in cultured cells and less pathogenicity in mice than the virus propagated from parental cells. In addition, this galectin-1-free EV71 virus was sensitive to high temperature and lost its viability after long-term storage, which could be restored following supplement of recombinant galectin-1. Taken together, our findings uncover a new role of galectin-1 in facilitating EV71 virus infection. PMID:25706563

  18. Carotenoid-dependent coloration of male American kestrels predicts ability to reduce parasitic infections

    NASA Astrophysics Data System (ADS)

    Dawson, Russell D.; Bortolotti, Gary R.

    2006-12-01

    The signaling function of sexually selected traits, such as carotenoid-dependent avian plumage coloration, has received a great deal of recent attention especially with respect to parasitism and immunocompetence. We argue that parasite-mediated models of sexual selection may have an implicit temporal component that many researchers have ignored. For example, previous studies have demonstrated that carotenoid-dependent traits can signal past parasite exposure, current levels of parasitism, or the ability of individuals to manage parasitic infections in the future. We examined repeated measures of carotenoid-dependent skin color and blood parasitism in American kestrels ( Falco sparverius) to distinguish whether coloration might signal current parasitism or the potential to deal with infections in the future. We found no evidence that coloration was related to current levels of parasitism in either sex. However, coloration of males significantly predicted their response to parasitism; males with bright orange coloration during prelaying, when mate choice is occurring, were more likely than dull yellow males to reduce their levels of infection by the time incubation began. Coloration during prelaying may advertise a male’s health later in the breeding season. For kestrels, the ability to predict future health would be highly beneficial given the male’s role in providing food to his mate and offspring. Coloration of females was not a significant predictor of parasitism in the future, and we provide several possible explanations for this result.

  19. Secondary Defense Chemicals in Milkweed Reduce Parasite Infection in Monarch Butterflies, Danaus plexippus.

    PubMed

    Gowler, Camden D; Leon, Kristoffer E; Hunter, Mark D; de Roode, Jacobus C

    2015-06-01

    In tri-trophic systems, herbivores may benefit from their host plants in fighting parasitic infections. Plants can provide parasite resistance in two contrasting ways: either directly, by interfering with the parasite, or indirectly, by increasing herbivore immunity or health. In monarch butterflies, the larval diet of milkweed strongly influences the fitness of a common protozoan parasite. Toxic secondary plant chemicals known as cardenolides correlate strongly with parasite resistance of the host, with greater cardenolide concentrations in the larval diet leading to lower parasite growth. However, milkweed cardenolides may covary with other indices of plant quality including nutrients, and a direct experimental link between cardenolides and parasite performance has not been established. To determine if the anti-parasitic activity of milkweeds is indeed due to secondary chemicals, as opposed to nutrition, we supplemented the diet of infected and uninfected monarch larvae with milkweed latex, which contains cardenolides but no nutrients. Across three experiments, increased dietary cardenolide concentrations reduced parasite growth in infected monarchs, which consequently had longer lifespans. However, uninfected monarchs showed no differences in lifespan across treatments, confirming that cardenolide-containing latex does not increase general health. Our results suggest that cardenolides are a driving force behind plant-derived resistance in this system. PMID:25953502

  20. Secondary Defense Chemicals in Milkweed Reduce Parasite Infection in Monarch Butterflies, Danaus plexippus.

    PubMed

    Gowler, Camden D; Leon, Kristoffer E; Hunter, Mark D; de Roode, Jacobus C

    2015-06-01

    In tri-trophic systems, herbivores may benefit from their host plants in fighting parasitic infections. Plants can provide parasite resistance in two contrasting ways: either directly, by interfering with the parasite, or indirectly, by increasing herbivore immunity or health. In monarch butterflies, the larval diet of milkweed strongly influences the fitness of a common protozoan parasite. Toxic secondary plant chemicals known as cardenolides correlate strongly with parasite resistance of the host, with greater cardenolide concentrations in the larval diet leading to lower parasite growth. However, milkweed cardenolides may covary with other indices of plant quality including nutrients, and a direct experimental link between cardenolides and parasite performance has not been established. To determine if the anti-parasitic activity of milkweeds is indeed due to secondary chemicals, as opposed to nutrition, we supplemented the diet of infected and uninfected monarch larvae with milkweed latex, which contains cardenolides but no nutrients. Across three experiments, increased dietary cardenolide concentrations reduced parasite growth in infected monarchs, which consequently had longer lifespans. However, uninfected monarchs showed no differences in lifespan across treatments, confirming that cardenolide-containing latex does not increase general health. Our results suggest that cardenolides are a driving force behind plant-derived resistance in this system.

  1. Antibodies Fused to Innate Immune Molecules Reduce Initiation of Cryptosporidium parvum Infection in Mice▿

    PubMed Central

    Imboden, Michael; Riggs, Michael W.; Schaefer, Deborah A.; Homan, E. Jane; Bremel, Robert D.

    2010-01-01

    At present no completely effective treatments are available for Cryptosporidium parvum infections in humans and livestock. Based on previous data showing the neutralizing potential of a panel of monoclonal antibodies developed against C. parvum, and based on the fact that innate immune peptides and enzymes have anticryptosporidial activity, we engineered several of these antibodies into antibody-biocide fusion proteins. We hypothesized that the combination of high-affinity antibody targeting with innate immune molecule-mediated killing would result in a highly effective new antiprotozoal agent. To test this hypothesis, we expressed antibody-biocide fusion proteins in a mammalian cell culture system and used the resulting products for in vitro and in vivo efficacy experiments. Antibody-biocide fusion proteins efficiently bound to, and destroyed, C. parvum sporozoites in vitro through a membrane-disruptive mechanism. When antibody-biocide fusion proteins were administered orally to neonatal mice in a prophylactic model of cryptosporidiosis, the induction of infection was reduced by as much as 81% in the mucosal epithelium of the gut, as determined on the basis of histopathological scoring of infectious stages. Several versions of antibody fusion proteins that differed in antigen specificity and in the biocide used had strong inhibitory effects on the initiation of infection. The results lay the groundwork for the development of a new class of antimicrobials effective against Cryptosporidium. PMID:20086143

  2. Improving awareness of best practices to reduce surgical site infection: a multistakeholder approach.

    PubMed

    Skoufalos, Alexandria; Clarke, Janice L; Napp, Marc; Abrams, Kenneth J; Berman, Bettina; Armellino, Donna; Schilling, Mary Ellen; Pracilio, Valerie

    2012-01-01

    Surgical site infection (SSI) is recognized as a focus area by the Centers for Medicare and Medicaid Services, the Joint Commission, the Institute for Healthcare Improvement, and the Institute of Medicine. An estimated 47% to 84% of SSIs present after discharge from the hospital or ambulatory care facility and, as a result, go undetected by standard SSI surveillance programs. Evidence-based processes and practices that are known to reduce the incidence of SSIs tend to be underused in routine practice. This article describes a multistakeholder process used to develop an educational initiative to raise awareness of best practices to reduce SSIs. The goal was to create a patient-centric educational initiative that involved an active partnership among all stakeholders-medical professional organizations, hospitals/health systems, health insurers, employers and other purchasers, and consumers/patients-to provide the climate necessary to create and sustain a culture of safety.

  3. The Impact of Implementation of Bundle to Reduce Catheter-Related Bloodstream Infection Rates

    PubMed Central

    Menegueti, Mayra Goncalves; Ardison, Kym Marcel Martins; Bellissimo-Rodrigues, Fernando; Gaspar, Gilberto Gambero; Martins-Filho, Olindo Assis; Puga, Marcelo Lourencini; Laus, Ana Maria; Basile-Filho, Anibal; Auxiliadora-Martins, Maria

    2015-01-01

    Background The aim of the study was to investigate how control bundles reduce the rate of central venous catheter-associated bloodstream infections (CVC-BSIs) rates in critically ill patients. Methods This is a prospective before-and-after study designed to evaluate whether a set of control measures (bundle) can help prevent CVC-BSI. The bundles included a checklist that aimed to correct practices related to CVC insertion, manipulation, and maintenance based on guidelines of the Center for Disease Control and Prevention (CDC). Results We examined 123 checklists before and 155 checklists after implementation of the training program. Compared with the pre-intervention period, CVC-BSI rates decreased. Hand hygiene techniques were used correctly. CVC-BSI incidence was 9.3 and 5.1 per 1,000 catheter-days before and after the training program, respectively. Conclusions The implementation of a bundle and training program effectively reduces CVC-BSI rates. PMID:26491498

  4. Reducing fungal infections and testing tag loss in juvenile Pacific lampreys implanted with passive integrated transponders.

    USGS Publications Warehouse

    Christiansen, H.E.; Gee, L.P.; Mesa, M.G.

    2012-01-01

    Pacific lamprey Entosphenus tridentatus are facing severe population declines, yet little is known about juvenile lamprey passage, life history, or adult return rates because until now, these small fish could not be tagged for unique identification of live individuals. Previously, we developed a simple and effective method for tagging juvenile lampreys with passive integrated transponder (PIT) tags and showed that tagging per se did not affect survival. Mortality in tagged and untagged control fish, however, was frequently associated with fungal infection. In this study, we addressed two outstanding issues related to handling and tagging juvenile lampreys. First, we tried to mitigate freshwater fungal infections by reducing irritation and stress from anesthesia and by treating tagged fish briefly with a prophylactic immediately after tagging. We tested four anesthetics at three concentrations each and determined that 100 mg/L MS-222 and 60 mg/L BENZOAK® (benzocaine) were the most effective for anesthetizing juvenile lampreys to handleable while minimizing irritation. We also showed that fish anesthetized with BENZOAK® may have lower rates of fungal infection than those anesthetized with MS-222 or AQUI-S® 20E (eugenol). When fish anesthetized with MS-222 or BENZOAK® were given a 30 min prophylactic treatment with Stress Coat®, hydrogen peroxide, or salt immediately after tagging, few fish presented with fungal infections. However, untreated, tagged control fish also showed few fungal infections, making it difficult to determine if the prophylactic treatments were successful. The second question we addressed was whether activity would increase tag loss in PIT-tagged lampreys. We found that active swimming did not cause tag loss if fish were first held for 20–24 h after tagging. Therefore, we recommend anesthesia with MS-222 or BENZOAK® and then tagging with a 20–24 h recovery period followed by immediate release. If field studies show that lampreys are not

  5. The UL13 and US3 Protein Kinases of Herpes Simplex Virus 1 Cooperate to Promote the Assembly and Release of Mature, Infectious Virions.

    PubMed

    Gershburg, Svetlana; Geltz, Joshua; Peterson, Karin E; Halford, William P; Gershburg, Edward

    2015-01-01

    Herpes simplex virus type 1 (HSV-1) encodes two bona fide serine/threonine protein kinases, the US3 and UL13 gene products. HSV-1 ΔUS3 mutants replicate with wild-type efficiency in cultured cells, and HSV-1 ΔUL13 mutants exhibit <10-fold reduction in infectious viral titers. Given these modest phenotypes, it remains unclear how the US3 and UL13 protein kinases contribute to HSV-1 replication. In the current study, we designed a panel of HSV-1 mutants, in which portions of UL13 and US3 genes were replaced by expression cassettes encoding mCherry protein or green fluorescent protein (GFP), respectively, and analyzed DNA replication, protein expression, and spread of these mutants in several cell types. Loss of US3 function alone had largely negligible effect on viral DNA accumulation, gene expression, virion release, and spread. Loss of UL13 function alone also had no appreciable effects on viral DNA levels. However, loss of UL13 function did result in a measurable decrease in the steady-state levels of two viral glycoproteins (gC and gD), release of total and infectious virions, and viral spread. Disruption of both genes did not affect the accumulation of viral DNA, but resulted in further reduction in gC and gD steady-state levels, and attenuation of viral spread and infectious virion release. These data show that the UL13 kinase plays an important role in the late phase of HSV-1 infection, likely by affecting virion assembly and/or release. Moreover, the data suggest that the combined activities of the US3 and UL13 protein kinases are critical to the efficient assembly and release of infectious virions from HSV-1-infected cells.

  6. Reduced Itraconazole Concentration and Durations Are Successful in Treating Batrachochytrium dendrobatidis Infection in Amphibians

    PubMed Central

    Brannelly, Laura A.

    2014-01-01

    Amphibians are experiencing the greatest decline of any vertebrate class and a leading cause of these declines is a fungal pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Captive assurance colonies are important worldwide for threatened amphibian species and may be the only lifeline for those in critical threat of extinction. Maintaining disease free colonies is a priority of captive managers, yet safe and effective treatments for all species and across life stages have not been identified. The most widely used chemotherapeutic treatment is itraconazole, although the dosage commonly used can be harmful to some individuals and species. We performed a clinical treatment trial to assess whether a lower and safer but effective dose of itraconazole could be found to cure Bd infections. We found that by reducing the treatment concentration from 0.01-0.0025% and reducing the treatment duration from 11-6 days of 5 min baths, frogs could be cured of Bd infection with fewer side effects and less treatment-associated mortality. PMID:24686573

  7. Reduced itraconazole concentration and durations are successful in treating Batrachochytrium dendrobatidis infection in amphibians.

    PubMed

    Brannelly, Laura A

    2014-03-14

    Amphibians are experiencing the greatest decline of any vertebrate class and a leading cause of these declines is a fungal pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Captive assurance colonies are important worldwide for threatened amphibian species and may be the only lifeline for those in critical threat of extinction. Maintaining disease free colonies is a priority of captive managers, yet safe and effective treatments for all species and across life stages have not been identified. The most widely used chemotherapeutic treatment is itraconazole, although the dosage commonly used can be harmful to some individuals and species. We performed a clinical treatment trial to assess whether a lower and safer but effective dose of itraconazole could be found to cure Bd infections. We found that by reducing the treatment concentration from 0.01-0.0025% and reducing the treatment duration from 11-6 days of 5 min baths, frogs could be cured of Bd infection with fewer side effects and less treatment-associated mortality.

  8. Propofol Increases Host Susceptibility to Microbial Infection by Reducing Subpopulations of Mature Immune Effector Cells at Sites of Infection

    PubMed Central

    Visvabharathy, Lavanya; Xayarath, Bobbi; Weinberg, Guy; Shilling, Rebecca A.; Freitag, Nancy E.

    2015-01-01

    Anesthetics are known to modulate host immune responses, but separating the variables of surgery from anesthesia when analyzing hospital acquired infections is often difficult. Here, the bacterial pathogen Listeria monocytogenes (Lm) was used to assess the impact of the common anesthetic propofol on host susceptibility to infection. Brief sedation of mice with physiologically relevant concentrations of propofol increased bacterial burdens in target organs by more than 10,000-fold relative to infected control animals. The adverse effects of propofol sedation on immune clearance of Lm persisted after recovery from sedation, as animals given the drug remained susceptible to infection for days following anesthesia. In contrast to propofol, sedation with alternative anesthetics such as ketamine/xylazine or pentobarbital did not increase susceptibility to systemic Lm infection. Propofol altered systemic cytokine and chemokine expression during infection, and prevented effective bacterial clearance by inhibiting the recruitment and/or activity of immune effector cells at sites of infection. Propofol exposure induced a marked reduction in marginal zone macrophages in the spleens of Lm infected mice, resulting in bacterial dissemination into deep tissue. Propofol also significantly increased mouse kidney abscess formation following infection with the common nosocomial pathogen Staphylococcus aureus. Taken together, these data indicate that even brief exposure to propofol severely compromises host resistance to microbial infection for days after recovery from sedation. PMID:26381144

  9. Prophylactic, therapeutic and neutralizing effects of zinc oxide tetrapod structures against herpes simplex virus type-2 infection

    PubMed Central

    Antoine, Thessicar; Mishra, Yogendra K.; Trigilio, James; Tiwari, Vaibhav; Adelung, Rainer; Shukla, Deepak

    2012-01-01

    The attachment of Herpes simplex virus type-2 (HSV-2) to a target cell requires ionic interactions between negatively charged cell surface co-receptor heparan sulfate (HS) and positively charged residues on viral envelop glycoproteins, gB and gC. Effective blocking of this first step of HSV-2 pathogenesis demonstrates significant prophylactic effects against the viral disease; any in vitro therapeutic effects of blocking this interaction, however, are not clear. Here, we provide new evidence that zinc oxide tetrapod micro-nanostructures synthesized by flame transport approach significantly block HSV-2 entry into target cells and, in addition, demonstrate the potential to stop the spread of the virus among already infected cells. The zinc oxide tetrapods (ZnOTs) also exhibit the ability to neutralize HSV-2 virions. Natural target cells such as human vaginal epithelial and HeLa cells showed highly reduced infectivity when infected with HSV-2 virions that were pre-incubated with the ZnOTs. The mechanism behind the ability of ZnOTs to prevent, neutralize or reduce HSV-2 infection relies on their ability to bind the HSV-2 virions. We used fluorescently labeled ZnOTs and GFP-expressing HSV-2 virions to demonstrate the binding of the ZnOTs with HSV-2. We also show that the binding and hence, the anti-viral effects of ZnOTs can be enhanced by illuminating the ZnOTs with UV light. Our results provide new insights into the anti-HSV-2 effects of ZnOT and rationalize their development as a HSV-2 trapping agent for the prevention and/or treatment of infection. The observed results also demonstrate that blocking HSV-2 attachment can have prophylactic as well as therapeutic applications. PMID:23047013

  10. Prophylactic, therapeutic and neutralizing effects of zinc oxide tetrapod structures against herpes simplex virus type-2 infection.

    PubMed

    Antoine, Thessicar E; Mishra, Yogendra K; Trigilio, James; Tiwari, Vaibhav; Adelung, Rainer; Shukla, Deepak

    2012-12-01

    The attachment of Herpes simplex virus type-2 (HSV-2) to a target cell requires ionic interactions between negatively charged cell surface co-receptor heparan sulfate (HS) and positively charged residues on viral envelop glycoproteins, gB and gC. Effective blocking of this first step of HSV-2 pathogenesis demonstrates significant prophylactic effects against the viral disease; any in vitro therapeutic effects of blocking this interaction, however, are not clear. Here, we provide new evidence that zinc oxide tetrapod micro-nanostructures synthesized by flame transport approach significantly block HSV-2 entry into target cells and, in addition, demonstrate the potential to stop the spread of the virus among already infected cells. The zinc oxide tetrapods (ZnOTs) also exhibit the ability to neutralize HSV-2 virions. Natural target cells such as human vaginal epithelial and HeLa cells showed highly reduced infectivity when infected with HSV-2 virions that were pre-incubated with the ZnOTs. The mechanism behind the ability of ZnOTs to prevent, neutralize or reduce HSV-2 infection relies on their ability to bind the HSV-2 virions. We used fluorescently labeled ZnOTs and GFP-expressing HSV-2 virions to demonstrate the binding of the ZnOTs with HSV-2. We also show that the binding and hence, the antiviral effects of ZnOTs can be enhanced by illuminating the ZnOTs with UV light. Our results provide new insights into the anti-HSV-2 effects of ZnOT and rationalize their development as a HSV-2 trapping agent for the prevention and/or treatment of infection. The observed results also demonstrate that blocking HSV-2 attachment can have prophylactic as well as therapeutic applications. PMID:23047013

  11. Herpes simplex virus VP16 rescues viral mRNA from destruction by the virion host shutoff function.

    PubMed

    Lam, Q; Smibert, C A; Koop, K E; Lavery, C; Capone, J P; Weinheimer, S P; Smiley, J R

    1996-05-15

    Herpes simplex virus (HSV) virions contain two regulatory proteins that facilitate the onset of the lytic cycle: VP16 activates transcription of the viral immediate-early genes, and vhs triggers shutoff of host protein synthesis and accelerated turnover of cellular and viral mRNAs. VP16 and vhs form a complex in infected cells, raising the possibility of a regulatory link between them. Here we show that viral protein synthesis and mRNA levels undergo a severe decline at intermediate times after infection with a VP16 null mutant, culminating in virtually complete translational arrest. This phenotype was rescued by a transcriptionally incompetent derivative of VP16 that retains vhs binding activity, and was eliminated by inactivating the vhs gene. These results indicate that VP16 dampens vhs activity, allowing HSV mRNAs to persist in infected cells. Further evidence supporting this hypothesis came from the demonstration that a stably transfected cell line expressing VP16 was resistant to host shutoff induced by superinfecting HSV virions. Thus, in addition to its well known function as a transcriptional activator, VP16 stimulates viral gene expression at a post-transcriptional level, by sparing viral mRNAs from degradation by one of the virus-induced host shutoff mechanisms.

  12. Abortive replication of Bombyx mori nucleopolyhedrovirus in Sf9 and High Five cells: Defective nuclear transport of the virions

    SciTech Connect

    Katou, Yasuhiro; Ikeda, Motoko; Kobayashi, Michihiro . E-mail: michihir@agr.nagoya-u.ac.jp

    2006-04-10

    Despite close genetic relationship, Bombyx mori nucleopolyhedrovirus (BmNPV) and Autographa californica multicapsid NPV (AcMNPV) display a distinct host range property. Here, BmNPV replication was examined in Sf9 and High Five cells that were nonproductive for BmNPV infection but supported high titers of AcMNPV replication. Recombinant BmNPV, vBm/gfp/lac, containing bm-ie1 promoter-driven egfp showed that few Sf9 and High Five cells infected with vBm/gfp/lac expressed EGFP, while large proportion of EGFP-expressing cells was observed when transfected with vBm/gfp/lac DNA. Immunocytochemical analysis showed that BmNPV was not imported into the nucleus of these two cell lines, while recombinant BmNPV, vBm{delta}64/ac-gp64 possessing AcMNPV gp64 was imported into the nucleus, yielding progeny virions in High Five cells, but not Sf9 cells. These results indicate that the defective nuclear import of infected virions due to insufficient BmNPV GP64 function is involved in the restricted BmNPV replication in Sf9 and High Five cells.

  13. An Aptamer against the Matrix Binding Domain on the Hepatitis B Virus Capsid Impairs Virion Formation

    PubMed Central

    Orabi, Ahmed; Bieringer, Maria; Geerlof, Arie

    2015-01-01

    ABSTRACT The hepatitis B virus (HBV) particle is an icosahedral nucleocapsid surrounded by a lipid envelope containing viral surface proteins. A small domain (matrix domain [MD]) in the large surface protein L and a narrow region (matrix binding domain [MBD]) including isoleucine 126 on the capsid surface have been mapped, in which point mutations such as core I126A specifically blocked nucleocapsid envelopment. It is possible that the two domains interact with each other during virion morphogenesis. By the systematic evolution of ligands by exponential enrichment (SELEX) method, we evolved DNA aptamers from an oligonucleotide library binding to purified recombinant capsids but not binding to the corresponding I126A mutant capsids. Aptamers bound to capsids were separated from unbound molecules by filtration. After 13 rounds of selections and amplifications, 16 different aptamers were found among 73 clones. The four most frequent aptamers represented more than 50% of the clones. The main aptamer, AO-01 (13 clones, 18%), showed the lowest dissociation constant (Kd) of 180 ± 82 nM for capsid binding among the four molecules. Its Kd for I126A capsids was 1,306 ± 503 nM. Cotransfection of Huh7 cells with AO-01 and an HBV genomic construct resulted in 47% inhibition of virion production at 3 days posttransfection, but there was no inhibition by cotransfection of an aptamer with a random sequence. The half-life of AO-01 in cells was 2 h, which might explain the incomplete inhibition. The results support the importance of the MBD for nucleocapsid envelopment. Inhibiting the MD-MBD interaction with a low-molecular-weight substance might represent a new approach for an antiviral therapy. IMPORTANCE Approximately 240 million people are persistently infected with HBV. To date, antiviral therapies depend on a single target, the viral reverse transcriptase. Future additional targets could be viral protein-protein interactions. We selected a 55-base-long single-stranded DNA

  14. Capillarity-induced disassembly of virions in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Fan, Xiaobin; Barclay, J. Elaine; Peng, Wenchao; Li, Yang; Li, Xianyu; Zhang, Guoliang; Evans, David J.; Zhang, Fengbao

    2008-04-01

    Studying the transport and fate of viruses through nanochannels is of great importance. By using the nanochannel of a carbon nanotube (CNT) as an ideal model, we evaluated the possibility of capillarity-induced viral transport through a closely fitting nanochannel and explored the mechanisms involved. It is shown both experimentally and theoretically that Cowpea mosaic virus can enter CNTs by capillarity. However, when introduced into a nanotube the protein capsid may disassemble. During the initial capillary filling stage, anomalous needle-shaped high pressure exists in the centre of the nanotube's entrance. This high pressure, combining with the significant negative pressure within the nanotube, may account for the disassembly of the virions.

  15. Stoichiometry of the antiviral protein APOBEC3G in HIV-1 virions.

    PubMed

    Xu, Hongzhan; Chertova, Elena; Chen, Jianbo; Ott, David E; Roser, James D; Hu, Wei-Shau; Pathak, Vinay K

    2007-04-10

    A host cytidine deaminase, APOBEC3G (A3G), inhibits replication of human immunodeficiency virus type 1 (HIV-1) by incorporating into virions in the absence of the virally encoded Vif protein (Deltavif virions), at least in part by causing G-to-A hypermutation. To gain insight into the antiretroviral function of A3G, we determined the quantities of A3G molecules that are incorporated in Deltavif virions. We combined three experimental approaches-reversed-phase high-pressure liquid chromatography (HPLC), scintillation proximity assay (SPA), and quantitative immunoblotting-to determine the molar ratio of A3G to HIV-1 capsid protein in Deltavif virions. Our studies revealed that the amount of the A3G incorporated into Deltavif virions was proportional to the level of its expression in the viral producing cells, and the ratio of the A3G to Gag in the Deltavif virions produced from activated human peripheral blood mononuclear cells (PBMC) was approximately 1:439. Based on previous estimates of the stoichiometry of HIV-1 Gag in virions (1400-5000), we conclude that approximately 7 (+/-4) molecules of A3G are incorporated into Deltavif virions produced from human PBMCs. These results indicate that virion incorporation of only a few molecules of A3G is sufficient to inhibit HIV-1 replication. PMID:17126871

  16. Cell Biological and Functional Characterization of the Vaccinia Virus F10 Kinase: Implications for the Mechanism of Virion Morphogenesis

    PubMed Central

    Punjabi, Almira; Traktman, Paula

    2005-01-01

    The vaccinia virus F10 protein is one of two virally encoded protein kinases. A phenotypic analysis of infections involving a tetracycline-inducible recombinant (vΔiF10) indicated that F10 is involved in the early stages of virion morphogenesis, as previously reported for the mutants ts28 and ts15. The proteins encoded by ts28 and ts15 have primary defects in enzymatic activity and thermostability, respectively. Using a transient complementation assay, we demonstrated that the enzymatic activity of F10 is essential for its biological function and that both its enzymatic and biological functions depend upon N-terminal sequences that precede the catalytic domain. An execution point analysis indicated that in addition to its role at the onset of morphogenesis, F10 is also required at later stages, when membrane crescents surround virosomal contents and develop into immature virions. The F10 protein is phosphorylated in vivo, appears to be tightly associated with intracellular membranes, and can bind to specific phosphoinositides in vitro. When F10 is repressed or impaired, the phosphorylation of several cellular and viral proteins appears to increase in intensity, suggesting that F10 may normally intersect with cellular signaling cascades via the activation of a phosphatase or the inhibition of another kinase. These cascades may drive the F10-induced remodeling of membranes that accompanies virion biogenesis. Upon the release of ts28-infected cultures from a 40°C-induced block, a synchronous resumption of morphogenesis that culminates in the production of infectious virus can be observed. The pharmacological agents H89 and cerulenin, which are inhibitors of endoplasmic reticulum exit site formation and de novo lipid synthesis, respectively, block this recovery. PMID:15681420

  17. Localization of the Houdinisome (Ejection Proteins) inside the Bacteriophage P22 Virion by Bubblegram Imaging

    PubMed Central

    Wu, Weimin; Leavitt, Justin C.; Cheng, Naiqian; Gilcrease, Eddie B.; Motwani, Tina; Teschke, Carolyn M.; Casjens, Sherwood R.

    2016-01-01

    ABSTRACT The P22 capsid is a T=7 icosahedrally symmetric protein shell with a portal protein dodecamer at one 5-fold vertex. Extending outwards from that vertex is a short tail, and putatively extending inwards is a 15-nm-long α-helical barrel formed by the C-terminal domains of portal protein subunits. In addition to the densely packed genome, the capsid contains three “ejection proteins” (E-proteins [gp7, gp16, and gp20]) destined to exit from the tightly sealed capsid during the process of DNA delivery into target cells. We estimated their copy numbers by quantitative SDS-PAGE as approximately 12 molecules per virion of gp16 and gp7 and 30 copies of gp20. To localize them, we used bubblegram imaging, an adaptation of cryo-electron microscopy in which gaseous bubbles induced in proteins by prolonged irradiation are used to map the proteins’ locations. We applied this technique to wild-type P22, a triple mutant lacking all three E-proteins, and three mutants each lacking one E-protein. We conclude that all three E-proteins are loosely clustered around the portal axis, in the region displaced radially inwards from the portal crown. The bubblegram data imply that approximately half of the α-helical barrel seen in the portal crystal structure is disordered in the mature virion, and parts of the disordered region present binding sites for E-proteins. Thus positioned, the E-proteins are strategically placed to pass down the shortened barrel and through the portal ring and the tail, as they exit from the capsid during an infection. PMID:27507825

  18. Down-regulated Th17 Responses Are Associated with Reduced Gastritis in Helicobacter pylori-infected Children

    PubMed Central

    Bimczok, Diane; Shaffer, Carrie L.; Cover, Timothy L.; Venegas, Alejandro; Salazar, Maria G.; Smythies, Lesley E.; Harris, Paul R.; Smith, Phillip D.

    2013-01-01

    Helicobacter pylori induces less gastric inflammation in children than adults. Here we investigated whether this reduced inflammation involves dysregulated Th17 responses. H. pylori-infected children and adults in Santiago, Chile had similar levels of H. pylori colonization, proportions of bacteria containing cagA and s1/s2 vacA markers of virulence and strain genotypes (predominantly hpEurope), but the children had significantly reduced levels of gastric inflammation and neutrophil infiltration. The reduced neutrophil accumulation in infected children was accompanied by significantly fewer gastric Th17 cells and significantly lower levels of IL-17-specific mRNA and protein compared to infected adults. The gastric mucosa of H. pylori-infected children also contained higher numbers of IL-10+ cells and increased levels of both IL-10 and Foxp3 mRNA compared to that of infected adults. Thus, reduced gastric inflammation, including diminished neutrophil accumulation, in H. pylori-infected children compared with infected adults is likely due to down-regulated gastric Th17/IL-17 responses as a consequence of enhanced mucosal regulatory T cell activity in the children. PMID:23299619

  19. Prednisolone reduces experimental arthritis, and inflammatory tissue destruction in SCID mice infected with Borrelia burgdorferi.

    PubMed

    Hurtenbach, U; Böggemeyer, E; Stehle, T; Museteanu, C; Del Pozo, E; Simon, M M

    1996-05-01

    Glucocorticosteroids (GC) are widely used as anti-inflammatory agents. The effects of Prednisolone on the development of Borrelia (B.) burgdorferi-induced clinical arthritis and organ inflammation was studied in severe combined immunodeficiency (SCID) mice. The drug was administered orally at a dose of 3, 10 and 30 mg/kg, starting shortly before experimental infection of the mice. A dose dependent inhibition of arthritic joint swelling was observed. Full protection was obtained with 30 mg/kg until 21 days after infection, subsequently, mild joint swelling developed but progression and severity of the disease was considerably less than in the other treated as well as in the untreated mice. Inhibition of clinical arthritis coincided with reduction of inflammatory cell infiltration in the joints, liver and muscle. Prednisolone was ineffective when application was initiated after arthritis was fully developed, i.e., 22 days after infection. Since the activated endothelium plays a critical role in development of inflammatory lesions, the expression of the cellular adhesion molecules (CAMs) E-selectin, P-selectin, ICAM-1 and VCAM-1 was determined in vitro using the bEnd3 endothelial cell line. Stimulation with a sonicated B. burgdorferi preparation in the presence of the water-soluble compound Prednisolone-21-hemisuccinate considerably reduced expression of ICAM-1, and marginally also of E-selectin, whereas the level of P-selectin and VCAM-1 remained unaltered. Thus, downregulation of ICAM-1 might be a critical factor in Prednisolone-mediated inhibition of B. burgdorferi-induced inflammation; the flare up of the disease after the initial protection indicates that additional therapy, e.g. with antibiotics, is necessary.

  20. Prednisolone reduces experimental arthritis, and inflammatory tissue destruction in SCID mice infected with Borrelia burgdorferi.

    PubMed

    Hurtenbach, U; Böggemeyer, E; Stehle, T; Museteanu, C; Del Pozo, E; Simon, M M

    1996-05-01

    Glucocorticosteroids (GC) are widely used as anti-inflammatory agents. The effects of Prednisolone on the development of Borrelia (B.) burgdorferi-induced clinical arthritis and organ inflammation was studied in severe combined immunodeficiency (SCID) mice. The drug was administered orally at a dose of 3, 10 and 30 mg/kg, starting shortly before experimental infection of the mice. A dose dependent inhibition of arthritic joint swelling was observed. Full protection was obtained with 30 mg/kg until 21 days after infection, subsequently, mild joint swelling developed but progression and severity of the disease was considerably less than in the other treated as well as in the untreated mice. Inhibition of clinical arthritis coincided with reduction of inflammatory cell infiltration in the joints, liver and muscle. Prednisolone was ineffective when application was initiated after arthritis was fully developed, i.e., 22 days after infection. Since the activated endothelium plays a critical role in development of inflammatory lesions, the expression of the cellular adhesion molecules (CAMs) E-selectin, P-selectin, ICAM-1 and VCAM-1 was determined in vitro using the bEnd3 endothelial cell line. Stimulation with a sonicated B. burgdorferi preparation in the presence of the water-soluble compound Prednisolone-21-hemisuccinate considerably reduced expression of ICAM-1, and marginally also of E-selectin, whereas the level of P-selectin and VCAM-1 remained unaltered. Thus, downregulation of ICAM-1 might be a critical factor in Prednisolone-mediated inhibition of B. burgdorferi-induced inflammation; the flare up of the disease after the initial protection indicates that additional therapy, e.g. with antibiotics, is necessary. PMID:8933206

  1. Reduced Immunocompetent B Cells and Increased Secondary Infection in Elderly Patients With Severe Sepsis.

    PubMed

    Suzuki, Kodai; Inoue, Shigeaki; Kametani, Yoshie; Komori, Yukako; Chiba, Sayuri; Sato, Takehito; Inokuchi, Sadaki; Ogura, Shinji

    2016-09-01

    Lymphocyte exhaustion was recently recognized as a mechanism of immunosuppression in sepsis. While B cells are known to play pivotal roles in bacterial infection and sepsis, changes in B-cell-mediated humoral immunity have not been evaluated in critically ill septic patients. We aimed to investigate changes in humoral immunity caused by defective B-cell function during severe sepsis. Thirty-three severe sepsis patients and 44 healthy subjects were prospectively enrolled. Blood was collected from patients within 72 h of and 8 to 11 h after sepsis onset to measure B-cell subtypes, serum immunoglobulin M concentration, and CpG-B oligodeoxynucleotide-induced immunoglobulin M (IgM) production ex vivo. Participants were divided into two age groups: adults (18-64 years) and elderly (≥65 years). The fraction of CD21 exhausted B cells in acute sepsis patients (3.18%) was higher than that observed in healthy donors (0.77%, respectively, P <0.01). Significantly, serum IgM in elderly septic patients (≥65 years) was negatively correlated with acute physiology and chronic health evaluation II score (r = -0.57, P <0.05). Consistently, in B cells stimulated ex vivo, both aging and sepsis induced significant reductions in supernatant IgM (P <0.01). This finding was clinically relevant, as elderly patients with decreased IgM production might be more susceptible to infection by Gram-negative bacteria and fungi. Reduced immunocompetent B cells may be related to increased secondary infection after sepsis, especially in the elderly. Finally, impaired humoral immunity with increased CD21 exhausted B cells and insufficient immunoglobulin M production may be a critical immunological change in sepsis. PMID:27172158

  2. Loss of Glycosaminoglycan Receptor Binding after Mosquito Cell Passage Reduces Chikungunya Virus Infectivity

    PubMed Central

    Acharya, Dhiraj; Paul, Amber M.; Anderson, John F.; Huang, Faqing; Bai, Fengwei

    2015-01-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that can cause fever and chronic arthritis in humans. CHIKV that is generated in mosquito or mammalian cells differs in glycosylation patterns of viral proteins, which may affect its replication and virulence. Herein, we compare replication, pathogenicity, and receptor binding of CHIKV generated in Vero cells (mammal) or C6/36 cells (mosquito) through a single passage. We demonstrate that mosquito cell-derived CHIKV (CHIKVmos) has slower replication than mammalian cell-derived CHIKV (CHIKVvero), when tested in both human and murine cell lines. Consistent with this, CHIKVmos infection in both cell lines produce less cytopathic effects and reduced antiviral responses. In addition, infection in mice show that CHIKVmos produces a lower level of viremia and less severe footpad swelling when compared with CHIKVvero. Interestingly, CHIKVmos has impaired ability to bind to glycosaminoglycan (GAG) receptors on mammalian cells. However, sequencing analysis shows that this impairment is not due to a mutation in the CHIKV E2 gene, which encodes for the viral receptor binding protein. Moreover, CHIKVmos progenies can regain GAG receptor binding capability and can replicate similarly to CHIKVvero after a single passage in mammalian cells. Furthermore, CHIKVvero and CHIKVmos no longer differ in replication when N-glycosylation of viral proteins was inhibited by growing these viruses in the presence of tunicamycin. Collectively, these results suggest that N-glycosylation of viral proteins within mosquito cells can result in loss of GAG receptor binding capability of CHIKV and reduction of its infectivity in mammalian cells. PMID:26484530

  3. Antibodies elicited by yeast glycoproteins recognize HIV-1 virions and potently neutralize virions with high mannose N-glycans.

    PubMed

    Zhang, Hong; Fu, Hu; Luallen, Robert J; Liu, Bingfen; Lee, Fang-Hua; Doms, Robert W; Geng, Yu

    2015-09-22

    The glycan shield on the human immunodeficiency virus 1 (HIV-1) envelope (Env) glycoprotein has drawn attention as a target for HIV-1 vaccine design given that an increasing number of potent and broadly neutralizing antibodies (bNAbs) recognize epitopes entirely or partially comprised of high mannose type N-linked glycans. In an attempt to generate immunogens that target the glycan shield of HIV-1, we previously engineered a triple mutant (TM) strain of Saccharomyces cerevisiae that results in exclusive presentation of high mannose type N-glycans, and identified five TM yeast glycoproteins that support strong binding of 2G12, a bNAb that targets a cluster of high mannose glycans on the gp120 subunit of Env. Here, we further analyzed the antigenicity and immunogenicity of these proteins in inducing anti-HIV responses. Our study demonstrated that the 2G12-reactive TM yeast glycoproteins efficiently bound to recently identified bNAbs including PGT125-130 and PGT135 that recognize high mannose glycan-dependent epitopes. Immunization of rabbits with a single TM yeast glycoprotein (Gp38 or Pst1), when conjugated to a promiscuous T-cell epitope peptide and coadministered with a Toll-like receptor 2 agonist, induced glycan-specific HIV-1 Env cross-reactive antibodies. The immune sera bound to both synthetic mannose oligosaccharides and gp120 proteins from a broad range of HIV-1 strains. The purified antibodies recognized and captured virions that contain both complex- and high mannose-type of N-glycans, and potently neutralized virions from different HIV-1 clades but only when the virions were enforced to retain high mannose N-glycans. This study provides insights into the elicitation of anti-carbohydrate, HIV-1 Env-cross reactive antibodies with a heterologous glycoprotein and may have applications in the design and administration of immunogens that target the viral glycan shield for development of an effective HIV-1 vaccine. PMID:26277072

  4. Reducing the risk of surgical site infections: does chlorhexidine gluconate provide a risk reduction benefit?

    PubMed

    Edmiston, Charles E; Bruden, Benjamin; Rucinski, Maria C; Henen, Cindy; Graham, Mary Beth; Lewis, Brian L

    2013-05-01

    Chlorhexidine gluconate (CHG) has been available as a topical antiseptic for over 50 years, having broad clinical application throughout the health care environment. Evidence-based clinical studies have shown chlorhexidine gluconate to be a safe and effective perioperative skin-prepping agent. Renewed interest has emerged for use of the antiseptic bath/shower to reduce the microbial skin burden prior to hospital admission. Recent clinical studies have documented that multiple applications of 2% or 4% CHG using a standardized protocol results in high skin surface concentrations sufficient to inhibit/kill skin colonizing flora, including methicillin-resistant Staphylococcus aureus. A new focus for the use of CHG in surgical patients involves irrigation of the wound prior to closure with 0.05% CHG followed by saline rinse. Recent laboratory studies suggest that, following a 1-minute exposure, 0.05% CHG produces a >5-log reduction against selective health care-associated pathogens and reduces microbial adherence to the surface of implantable biomedical devices. General, orthopedic, cardiothoracic, and obstetrical surgical studies have documented the safety of selective CHG formulations in elective surgical procedures. The following discussion will address both the evidence-based literature and preliminary findings suggesting that CHG has a broad and safe range of applications when used as an adjunctive interventional strategy for reducing the risk of postoperative surgical site infections (SSI). PMID:23622749

  5. Host response to various treatments to reduce Salmonella infections in swine.

    PubMed Central

    Letellier, A; Messier, S; Lessard, L; Chénier, S; Quessy, S

    2001-01-01

    Host response was evaluated following the administration of various treatments, such as probiotics, prebiotics, and vaccination, to reduce Salmonella in swine. Response to the treatments were studied by the evaluation of phagocytosis rates by flow cytometry, by studying the activation of whole-blood phagocytes by bioluminescence, the production of IgA against S. Typhimurium, and by histopathology. Significant differences were observed in the activation of whole-blood phagocytes in all groups of treated pigs (P = 0.0001). In SC54 vaccinated pigs, a significant reduction of Salmonella in the ileum was observed (P < 0.05) and the production of IgA against S. Typhimurium was higher in this group in comparison to uninfected control pigs (P = 0.0007). Furthermore, significant histopathological (P < 0.05) changes were observed in SC54 vaccinated pigs. Villus height and mucus and goblet cells density in the small intestine were reduced in vaccinated pigs in comparison to infected control pigs. Taken together, these findings suggest that SC54 vaccine can stimulate local immunity and reduce the presence of Salmonella in the ileum in swine. Use of SC54 vaccine should thus be considered in further field experiments. PMID:11480522

  6. Maraviroc Reduces Arterial Stiffness in PI-Treated HIV-infected Patients

    PubMed Central

    Piconi, Stefania; Pocaterra, Daria; Rainone, Veronica; Cossu, Maria; Masetti, Michela; Rizzardini, Giuliano; Clerici, Mario; Trabattoni, Daria

    2016-01-01

    The Δ32-CCR5 deletion of the CCR5 receptor is protective toward coronary artery pathology and myocardial infarction. Maraviroc (MVC), a CCR5 antagonist, was recently introduced in the therapy of HIV infection; we evaluated whether this drug could modulate the atherosclerotic burden in aviremic PI-treated HIV-positive individuals who underwent MVC intensification. Thus, the effect of MVC on intima media thickness, arterial stiffness, metabolic parameters, pro-inflammatory cytokines, endothelial dysfunction, and microbial traslocation markers was analyzed in 6 aviremic PI-treated HIV-positive individuals and were compared to those obtained in 9 additional aviremic PI-treated subjects that were enrolled retrospectively from our outpatients cohort. MVC intensification resulted in a significant reduction in intima media thickness, pulse wave velocity and triglycerides compared to baseline. Notably, MVC was also associated with a significant reduction of IL-6, microbial translocation indexes, sICAM and sVCAM; these changes were maintained throughout the 6 months of MVC intensification. No significant modifications were observed in CD4 counts, HIV viral load, and cholesterolemia. Results herein support a role of CCR5 antagonists in reducing the cardiovascular risk in HIV-infection. The hampering of inflammation, microbial translocation and the improvement of endothelial function could justify the protective role of CCR5 antagonists on atherosclerotic burden. PMID:27352838

  7. Drug-eluting Ti wires with titania nanotube arrays for bone fixation and reduced bone infection

    NASA Astrophysics Data System (ADS)

    Gulati, Karan; Aw, Moom Sinn; Losic, Dusan

    2011-10-01

    Current bone fixation technology which uses stainless steel wires known as Kirschner wires for fracture fixing often causes infection and reduced skeletal load resulting in implant failure. Creating new wires with drug-eluting properties to locally deliver drugs is an appealing approach to address some of these problems. This study presents the use of titanium [Ti] wires with titania nanotube [TNT] arrays formed with a drug delivery capability to design alternative bone fixation tools for orthopaedic applications. A titania layer with an array of nanotube structures was synthesised on the surface of a Ti wire by electrochemical anodisation and loaded with antibiotic (gentamicin) used as a model of bone anti-bacterial drug. Successful fabrication of TNT structures with pore diameters of approximately 170 nm and length of 70 μm is demonstrated for the first time in the form of wires. The drug release characteristics of TNT-Ti wires were evaluated, showing a two-phase release, with a burst release (37%) and a slow release with zero-order kinetics over 11 days. These results confirmed our system's ability to be applied as a drug-eluting tool for orthopaedic applications. The established biocompatibility of TNT structures, closer modulus of elasticity to natural bones and possible inclusion of desired drugs, proteins or growth factors make this system a promising alternative to replace conventional bone implants to prevent bone infection and to be used for targeted treatment of bone cancer, osteomyelitis and other orthopaedic diseases.

  8. Disrupting protein expression with Peptide Nucleic Acids reduces infection by obligate intracellular Rickettsia.

    PubMed

    Pelc, Rebecca S; McClure, Jennifer C; Kaur, Simran J; Sears, Khandra T; Rahman, M Sayeedur; Ceraul, Shane M

    2015-01-01

    Peptide Nucleic Acids (PNAs) are single-stranded synthetic nucleic acids with a pseudopeptide backbone in lieu of the phosphodiester linked sugar and phosphate found in traditional oligos. PNA designed complementary to the bacterial Shine-Dalgarno or start codon regions of mRNA disrupts translation resulting in the transient reduction in protein expression. This study examines the use of PNA technology to interrupt protein expression in obligate intracellular Rickettsia sp. Their historically intractable genetic system limits characterization of protein function. We designed PNA targeting mRNA for rOmpB from Rickettsia typhi and rickA from Rickettsia montanensis, ubiquitous factors important for infection. Using an in vitro translation system and competitive binding assays, we determined that our PNAs bind target regions. Electroporation of R. typhi and R. montanensis with PNA specific to rOmpB and rickA, respectively, reduced the bacteria's ability to infect host cells. These studies open the possibility of using PNA to suppress protein synthesis in obligate intracellular bacteria.

  9. Tail-interacting protein TIP47 is a connector between Gag and Env and is required for Env incorporation into HIV-1 virions

    PubMed Central

    Lopez-Vergès, Sandra; Camus, Grégory; Blot, Guillaume; Beauvoir, Roxane; Benarous, Richard; Berlioz-Torrent, Clarisse

    2006-01-01

    The presence of the envelope glycoprotein Env in HIV-1 virions is essential for infectivity. To date, the molecular mechanism by which Env is packaged into virions has been largely unknown. Here, we show that TIP47 (tail-interacting protein of 47 kDa), which has been shown to interact with Env, also binds the MA (matrix) domain of HIV-1 Gag protein and that these three proteins form a ternary complex. Mutations in Gag that abrogate interaction with TIP47 inhibit Env incorporation and virion infectivity as well as colocalization between Gag and Env. We also show that TIP47 silencing impairs Env incorporation and infectivity and abolishes coimmunoprecipitation of Gag with Env. In contrast, overexpression of TIP47 increases Env packaging. Last, we demonstrate that TIP47 can interact simultaneously with Env and Gag. Taken together, our results show that TIP47 is a cellular cofactor that plays an essential role in Env incorporation, allowing the encounter and the physical association between HIV-1 Gag and Env proteins during the viral assembly process. PMID:17003132

  10. Tail-interacting protein TIP47 is a connector between Gag and Env and is required for Env incorporation into HIV-1 virions.

    PubMed

    Lopez-Vergès, Sandra; Camus, Grégory; Blot, Guillaume; Beauvoir, Roxane; Benarous, Richard; Berlioz-Torrent, Clarisse

    2006-10-01

    The presence of the envelope glycoprotein Env in HIV-1 virions is essential for infectivity. To date, the molecular mechanism by which Env is packaged into virions has been largely unknown. Here, we show that TIP47 (tail-interacting protein of 47 kDa), which has been shown to interact with Env, also binds the MA (matrix) domain of HIV-1 Gag protein and that these three proteins form a ternary complex. Mutations in Gag that abrogate interaction with TIP47 inhibit Env incorporation and virion infectivity as well as colocalization between Gag and Env. We also show that TIP47 silencing impairs Env incorporation and infectivity and abolishes coimmunoprecipitation of Gag with Env. In contrast, overexpression of TIP47 increases Env packaging. Last, we demonstrate that TIP47 can interact simultaneously with Env and Gag. Taken together, our results show that TIP47 is a cellular cofactor that plays an essential role in Env incorporation, allowing the encounter and the physical association between HIV-1 Gag and Env proteins during the viral assembly process.

  11. Herpesvirus gB-induced fusion between the virion envelope and outer nuclear membrane during virus egress is regulated by the viral US3 kinase.

    PubMed

    Wisner, Todd W; Wright, Catherine C; Kato, Akihisa; Kawaguchi, Yasushi; Mou, Fan; Baines, Joel D; Roller, Richard J; Johnson, David C

    2009-04-01

    Herpesvirus capsids collect along the inner surface of the nuclear envelope and bud into the perinuclear space. Enveloped virions then fuse with the outer nuclear membrane (NM). We previously showed that herpes simplex virus (HSV) glycoproteins gB and gH act in a redundant fashion to promote fusion between the virion envelope and the outer NM. HSV mutants lacking both gB and gH accumulate enveloped virions in herniations, vesicles that bulge into the nucleoplasm. Earlier studies had shown that HSV mutants lacking the viral serine/threonine kinase US3 also accumulate herniations. Here, we demonstrate that HSV gB is phosphorylated in a US3-dependent manner in HSV-infected cells, especially in a crude nuclear fraction. Moreover, US3 directly phosphorylated the gB cytoplasmic (CT) domain in in vitro assays. Deletion of gB in the context of a US3-null virus did not add substantially to defects in nuclear egress. The majority of the US3-dependent phosphorylation of gB involved the CT domain and amino acid T887, a residue present in a motif similar to that recognized by US3 in other proteins. HSV recombinants lacking gH and expressing either gB substitution mutation T887A or a gB truncated at residue 886 displayed substantial defects in nuclear egress. We concluded that phosphorylation of the gB CT domain is important for gB-mediated fusion with the outer NM. This suggested a model in which the US3 kinase is incorporated into the tegument layer (between the capsid and envelope) in HSV virions present in the perinuclear space. By this packaging, US3 might be brought close to the gB CT tail, leading to phosphorylation and triggering fusion between the virion envelope and the outer NM.

  12. Quantitation of HLA Class II Protein Incorporated into Human Immunodeficiency Type 1 Virions Purified by Anti-CD45 Immunoaffinity Depletion of Microvesicles

    PubMed Central

    Trubey, Charles M.; Chertova, Elena; Coren, Lori V.; Hilburn, Joanne M.; Hixson, Catherine V.; Nagashima, Kunio; Lifson, Jeffrey D.; Ott, David E.

    2003-01-01

    Among the many host cell-derived proteins found in human immunodeficiency virus type 1 (HIV-1), HLA class II (HLA-II) appears to be selectively incorporated onto virions and may contribute to mechanisms of indirect imunopathogenesis in HIV infection and AIDS. However, the amount of HLA-II on the surface of HIV-1 particles has not been reliably determined due to contamination of virus preparations by microvesicles containing host cell proteins, including HLA-II. Even rigorous sucrose density centrifugation is unable to completely separate HIV-1 from microvesicles. CD45, a leukocyte integral membrane protein, is found on microvesicles, yet appears to be excluded from HIV-1 particles. Exploiting this observation, we have developed a CD45-based immunoaffinity depletion method for removing CD45-containing microvesicles that yields highly purified preparations of virions. Examination of CD45-depleted HIV-1MN by high-pressure liquid chromatography, protein sequencing, and amino acid analyses determined a molar ratio of HLA-II to Gag of 0.04 to 0.05 in the purified virions, corresponding to an estimated average of 50 to 63 native HLA-II complexes (i.e., a dimer of α and β heterodimers) per virion. These values are approximately 5- to 10-fold lower than those previously determined for other virion preparations that contained microvesicles. Our observations demonstrate the utility of CD45 immunoaffinity-based approaches for producing highly purified retrovirus preparations for applications that would benefit from the use of virus that is essentially free of microvesicles. PMID:14610192

  13. Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response.

    PubMed

    Garza-Cuartero, L; O'Sullivan, J; Blanco, A; McNair, J; Welsh, M; Flynn, R J; Williams, D; Diggle, P; Cassidy, J; Mulcahy, G

    2016-07-01

    Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long-standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co-infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis-specific Th1 immune response. We hypothesized that these changes in co-infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co-infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte-derived macrophages (MDM) from F. hepatica-infected cattle which is associated with suppression of pro-inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica-infected cattle is increased. These findings reflecting the bystander effect of helminth-induced downregulation of pro-inflammatory responses provide insights to understand host-pathogen interactions in co-infection.

  14. Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response.

    PubMed

    Garza-Cuartero, L; O'Sullivan, J; Blanco, A; McNair, J; Welsh, M; Flynn, R J; Williams, D; Diggle, P; Cassidy, J; Mulcahy, G

    2016-07-01

    Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long-standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co-infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis-specific Th1 immune response. We hypothesized that these changes in co-infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co-infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte-derived macrophages (MDM) from F. hepatica-infected cattle which is associated with suppression of pro-inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica-infected cattle is increased. These findings reflecting the bystander effect of helminth-induced downregulation of pro-inflammatory responses provide insights to understand host-pathogen interactions in co-infection. PMID:27108767

  15. The Surprising Role of Amyloid Fibrils in HIV Infection.

    PubMed

    Castellano, Laura M; Shorter, James

    2012-01-01

    Despite its discovery over 30 years ago, human immunodeficiency virus (HIV) continues to threaten public health worldwide. Semen is the principal vehicle for the transmission of this retrovirus and several endogenous peptides in semen, including fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120) and semenogelins (SEM1 and SEM2), assemble into amyloid fibrils that promote HIV infection. For example, PAP248-286 fibrils, termed SEVI (Semen derived Enhancer of Viral Infection), potentiate HIV infection by up to 105-fold. Fibrils enhance infectivity by facilitating virion attachment and fusion to target cells, whereas soluble peptides have no effect. Importantly, the stimulatory effect is greatest at low viral titers, which mimics mucosal transmission of HIV, where relatively few virions traverse the mucosal barrier. Devising a method to rapidly reverse fibril formation (rather than simply inhibit it) would provide an innovative and urgently needed preventative strategy for reducing HIV infection via the sexual route. Targeting a host-encoded protein conformer represents a departure from traditional microbicidal approaches that target the viral machinery, and could synergize with direct antiviral approaches. Here, we review the identification of these amyloidogenic peptides, their mechanism of action, and various strategies for inhibiting their HIV-enhancing effects.

  16. Fine structure of the vaccinia virion determined by controlled degradation and immunolocalization

    PubMed Central

    Moussatche, Nissin; Condit, Richard C.

    2014-01-01

    The vaccinia virion is a membraned, slightly flattened, barrel-shaped particle, with a complex internal structure featuring a biconcave core flanked by lateral bodies. Although the architecture of the purified mature virion has been intensely characterized by electron microscopy, the distribution of the proteins within the virion has been examined primarily using biochemical procedures. Thus, it has been shown that non-ionic and ionic detergents combined or not with a sulfhydryl reagent can be used to disrupt virions and, to a limited degree, separate the constituent proteins in different fractions. Applying a controlled degradation technique to virions adsorbed on EM grids, we were able to immuno-localize viral proteins within the virion particle. Our results show after NP40 and DTT treatment, membrane proteins are removed from the virion surface revealing proteins that are associated with the lateral bodies and the outer layer of the core wall. Combined treatment using high salt and high DTT removed lateral body proteins and exposed proteins of the internal core wall. Cores treated with proteases could be disrupted and the internal components were exposed. Cts8, a mutant in the A3 protein, produces aberrant virus that, when treated with NP-40 and DTT, release to the exterior the virus DNA associated with other internal core proteins. With these results, we are able to propose a model for the structure the vaccinia virion. PMID:25486587

  17. Fine structure of the vaccinia virion determined by controlled degradation and immunolocalization

    SciTech Connect

    Moussatche, Nissin Condit, Richard C.

    2015-01-15

    The vaccinia virion is a membraned, slightly flattened, barrel-shaped particle, with a complex internal structure featuring a biconcave core flanked by lateral bodies. Although the architecture of the purified mature virion has been intensely characterized by electron microscopy, the distribution of the proteins within the virion has been examined primarily using biochemical procedures. Thus, it has been shown that non-ionic and ionic detergents combined or not with a sulfhydryl reagent can be used to disrupt virions and, to a limited degree, separate the constituent proteins in different fractions. Applying a controlled degradation technique to virions adsorbed on EM grids, we were able to immuno-localize viral proteins within the virion particle. Our results show after NP40 and DTT treatment, membrane proteins are removed from the virion surface revealing proteins that are associated with the lateral bodies and the outer layer of the core wall. Combined treatment using high salt and high DTT removed lateral body proteins and exposed proteins of the internal core wall. Cores treated with proteases could be disrupted and the internal components were exposed. Cts8, a mutant in the A3 protein, produces aberrant virus that, when treated with NP-40 and DTT, releases to the exterior the virus DNA associated with other internal core proteins. With these results, we are able to propose a model for the structure the vaccinia virion.

  18. Infection of vascular endothelial cells with herpes simplex virus enhances tissue factor activity and reduces thrombomodulin expression.

    PubMed Central

    Key, N S; Vercellotti, G M; Winkelmann, J C; Moldow, C F; Goodman, J L; Esmon, N L; Esmon, C T; Jacob, H S

    1990-01-01

    Latent infection of vascular cells with herpes-viruses may play a pathogenic role in the development of human atherosclerosis. In a previous study, we found that cultured human umbilical vein endothelial cells (HUVECs) infected with herpes simplex virus 1 (HSV-1) became procoagulant, exemplified both by their enhanced assembly of the prothrombinase complex and by their inability to reduce adhesion of platelets. We now report two further procoagulant consequences of endothelial HSV infection: loss of surface thrombomodulin (TM) activity and induction of synthesis of tissue factor. Within 4 hr of infection of HUVECs, TM activity measured by thrombin-dependent protein C activation declined 21 +/- 3% (P less than 0.05) and by 18 hr, 48 +/- 5% (P less than 0.001). Similar significant TM decrements accompanied infection of bovine aortic endothelial cells. Identical TM loss was induced with HSV-2 infection but not with adenovirus infection. Decreased surface expression of TM antigen (measured by the specific binding of a polyclonal antibody to bovine TM) closely paralleled the loss of TM activity. As examined by Northern blotting, these losses apparently reflected rapid onset (within 4 hr of HSV infection) loss of mRNA for TM. In contrast, HSV infection induced a viral-dose-dependent increase in synthesis of tissue factor protein, adding to the procoagulant state. The results indicate that loss of endothelial protein-synthetic capacity is not a universal effect of HSV infection. We suggest that the procoagulant state induced by reduction in TM activity and amplified tissue factor activity accompanying HSV infection of endothelium could contribute to deposition of thrombi on atherosclerotic plaques and to the "coagulant-necrosis" state that characterizes HSV-infected mucocutaneous lesions. Images PMID:2169619

  19. Public perceptions of non-pharmaceutical interventions for reducing transmission of respiratory infection: systematic review and synthesis of qualitative studies

    PubMed Central

    2014-01-01

    Background Non-pharmaceutical public health interventions may provide simple, low-cost, effective ways of minimising the transmission and impact of acute respiratory infections in pandemic and non-pandemic contexts. Understanding what influences the uptake of non-pharmaceutical interventions such as hand and respiratory hygiene, mask wearing and social distancing could help to inform the development of effective public health advice messages. The aim of this synthesis was to explore public perceptions of non-pharmaceutical interventions that aim to reduce the transmission of acute respiratory infections. Methods Five online databases (MEDLINE, PsycINFO, CINAHL, EMBASE and Web of Science) were systematically searched. Reference lists of articles were also examined. We selected papers that used a qualitative research design to explore perceptions and beliefs about non-pharmaceutical interventions to reduce transmission of acute respiratory infections. We excluded papers that only explored how health professionals or children viewed non-pharmaceutical respiratory infection control. Three authors performed data extraction and assessment of study quality. Thematic analysis and components of meta-ethnography were adopted to synthesise findings. Results Seventeen articles from 16 studies in 9 countries were identified and reviewed. Seven key themes were identified: perceived benefits of non-pharmaceutical interventions, perceived disadvantages of non-pharmaceutical interventions, personal and cultural beliefs about infection transmission, diagnostic uncertainty in emerging respiratory infections, perceived vulnerability to infection, anxiety about emerging respiratory infections and communications about emerging respiratory infections. The synthesis showed that some aspects of non-pharmaceutical respiratory infection control (particularly hand and respiratory hygiene) were viewed as familiar and socially responsible actions to take. There was ambivalence about adopting

  20. Inosine-containing RNA is a novel innate immune recognition element and reduces RSV infection.

    PubMed

    Liao, Jie-ying; Thakur, Sheetal A; Zalinger, Zachary B; Gerrish, Kevin E; Imani, Farhad

    2011-01-01

    During viral infections, single- and double-stranded RNA (ssRNA and dsRNA) are recognized by the host and induce innate immune responses. The cellular enzyme ADAR-1 (adenosine deaminase acting on RNA-1) activation in virally infected cells leads to presence of inosine-containing RNA (Ino-RNA). Here we report that ss-Ino-RNA is a novel viral recognition element. We synthesized unmodified ssRNA and ssRNA that had 6% to16% inosine residues. The results showed that in primary human cells, or in mice, 10% ss-Ino-RNA rapidly and potently induced a significant increase in inflammatory cytokines, such as interferon (IFN)-β (35 fold), tumor necrosis factor (TNF)-α (9.7 fold), and interleukin (IL)-6 (11.3 fold) (p<0.01). Flow cytometry data revealed a corresponding 4-fold increase in influx of neutrophils into the lungs by ss-Ino-RNA treatment. In our in vitro experiments, treatment of epithelial cells with ss-Ino-RNA reduced replication of respiratory syncytial virus (RSV). Interestingly, RNA structural analysis showed that ss-Ino-RNA had increased formation of secondary structures. Our data further revealed that extracellular ss-Ino-RNA was taken up by scavenger receptor class-A (SR-A) which activated downstream MAP Kinase pathways through Toll-like receptor 3 (TLR3) and dsRNA-activated protein kinase (PKR). Our data suggests that ss-Ino-RNA is an as yet undescribed virus-associated innate immune stimulus.

  1. HIV-1 Integrase Binds the Viral RNA Genome and Is Essential during Virion Morphogenesis.

    PubMed

    Kessl, Jacques J; Kutluay, Sebla B; Townsend, Dana; Rebensburg, Stephanie; Slaughter, Alison; Larue, Ross C; Shkriabai, Nikoloz; Bakouche, Nordine; Fuchs, James R; Bieniasz, Paul D; Kvaratskhelia, Mamuka

    2016-08-25

    While an essential role of HIV-1 integrase (IN) for integration of viral cDNA into human chromosome is established, studies with IN mutants and allosteric IN inhibitors (ALLINIs) have suggested that IN can also influence viral particle maturation. However, it has remained enigmatic as to how IN contributes to virion morphogenesis. Here, we demonstrate that IN directly binds the viral RNA genome in virions. These interactions have specificity, as IN exhibits distinct preference for select viral RNA structural elements. We show that IN substitutions that selectively impair its binding to viral RNA result in eccentric, non-infectious virions without affecting nucleocapsid-RNA interactions. Likewise, ALLINIs impair IN binding to viral RNA in virions of wild-type, but not escape mutant, virus. These results reveal an unexpected biological role of IN binding to the viral RNA genome during virion morphogenesis and elucidate the mode of action of ALLINIs. PMID:27565348

  2. The Role of the Membrane in the Structure and Biophysical Robustness of the Dengue Virion Envelope

    PubMed Central

    Reddy, Tyler; Sansom, Mark S.P.

    2016-01-01

    Summary The dengue virion is surrounded by an envelope of membrane proteins surrounding a lipid bilayer. We have combined the cryoelectron microscopy structures of the membrane proteins (PDB: 3J27) with a lipid bilayer whose composition is based on lipidomics data for insect cell membranes, to obtain a near-atomic resolution computational model of the envelope of the dengue virion. A coarse-grained molecular dynamics simulation on the microsecond timescale enables analysis of key biophysical properties of the dengue outer envelope. Properties analyzed include area per lipid values (for a spherical virion with a mixed lipid composition), bilayer thickness, and lipid diffusion coefficients. Despite the absence of cholesterol from the lipid bilayer, the virion exhibits biophysical robustness (slow lipid diffusion alongside stable bilayer thickness, virion diameter, and shape) that matches the cholesterol-rich membrane of influenza A, with similarly anomalous diffusion of lipids. Biophysical robustness of the envelope may confer resilience to environmental perturbations. PMID:26833387

  3. The Role of the Membrane in the Structure and Biophysical Robustness of the Dengue Virion Envelope.

    PubMed

    Reddy, Tyler; Sansom, Mark S P

    2016-03-01

    The dengue virion is surrounded by an envelope of membrane proteins surrounding a lipid bilayer. We have combined the cryoelectron microscopy structures of the membrane proteins (PDB: 3J27) with a lipid bilayer whose composition is based on lipidomics data for insect cell membranes, to obtain a near-atomic resolution computational model of the envelope of the dengue virion. A coarse-grained molecular dynamics simulation on the microsecond timescale enables analysis of key biophysical properties of the dengue outer envelope. Properties analyzed include area per lipid values (for a spherical virion with a mixed lipid composition), bilayer thickness, and lipid diffusion coefficients. Despite the absence of cholesterol from the lipid bilayer, the virion exhibits biophysical robustness (slow lipid diffusion alongside stable bilayer thickness, virion diameter, and shape) that matches the cholesterol-rich membrane of influenza A, with similarly anomalous diffusion of lipids. Biophysical robustness of the envelope may confer resilience to environmental perturbations.

  4. Global changes in the RNA binding specificity of HIV-1 Gag regulate virion genesis

    PubMed Central

    Kutluay, Sebla B.; Zang, Trinity; Blanco-Melo, Daniel; Powell, Chelsea; Jannain, David; Errando, Manel; Bieniasz, Paul D.

    2014-01-01

    Summary The HIV-1 Gag protein orchestrates all steps of virion genesis, including membrane targeting and RNA recruitment into virions. Using crosslinking-immunoprecipitation (CLIP) sequencing, we uncover several dramatic changes in the RNA binding properties of Gag that occur during virion genesis, coincident with membrane binding, multimerization and proteolytic maturation. Prior to assembly, and after virion assembly and maturation, the nucleocapsid domain of Gag preferentially binds to psi and Rev Response elements in the viral genome, and GU-rich mRNA sequences. However, during virion genesis, this specificity transiently changes in a manner that facilitates genome packaging; nucleocapsid binds to many sites on the HIV-1 genome and to mRNA sequences with a HIV-1-like, A-rich nucleotide composition. Additionally, we find that the matrix domain of Gag binds almost exclusively to specific tRNAs in the cytosol, and this association regulates Gag binding to cellular membranes. PMID:25416948

  5. Global changes in the RNA binding specificity of HIV-1 gag regulate virion genesis.

    PubMed

    Kutluay, Sebla B; Zang, Trinity; Blanco-Melo, Daniel; Powell, Chelsea; Jannain, David; Errando, Manel; Bieniasz, Paul D

    2014-11-20

    The HIV-1 Gag protein orchestrates all steps of virion genesis, including membrane targeting and RNA recruitment into virions. Using crosslinking-immunoprecipitation (CLIP) sequencing, we uncover several dramatic changes in the RNA-binding properties of Gag that occur during virion genesis, coincident with membrane binding, multimerization, and proteolytic maturation. Prior to assembly, and after virion assembly and maturation, the nucleocapsid domain of Gag preferentially binds to psi and Rev Response elements in the viral genome, and GU-rich mRNA sequences. However, during virion genesis, this specificity transiently changes in a manner that facilitates genome packaging; nucleocapsid binds to many sites on the HIV-1 genome and to mRNA sequences with a HIV-1-like, A-rich nucleotide composition. Additionally, we find that the matrix domain of Gag binds almost exclusively to specific tRNAs in the cytosol, and this association regulates Gag binding to cellular membranes.

  6. Retrograde Trafficking Inhibitor of Shiga Toxins Reduces Morbidity and Mortality of Mice Infected with Enterohemorrhagic Escherichia coli

    PubMed Central

    Secher, T.; Shima, A.; Hinsinger, K.; Cintrat, J. C.; Johannes, L.; Barbier, J.; Gillet, D.

    2015-01-01

    The most deadly outbreak of Escherichia coli O104:H4 occurred in Europe in 2011. Here, we evaluated the effects of the retrograde trafficking inhibitor Retro-2cycl in a murine model of E. coli O104:H4 infection. Systemic treatment with Retro-2cycl significantly reduced body weight loss and improved clinical scores and survival rates for O104:H4-infected mice. The present data established that Retro-2cycl contributes to the protection of mice against O104:H4 infection and may represent a novel approach to limit Shiga toxin-producing Escherichia coli (STEC)-induced toxicity. PMID:25987610

  7. Quantitative real-time single particle analysis of virions.

    PubMed

    Heider, Susanne; Metzner, Christoph

    2014-08-01

    Providing information about single virus particles has for a long time been mainly the domain of electron microscopy. More recently, technologies have been developed-or adapted from other fields, such as nanotechnology-to allow for the real-time quantification of physical virion particles, while supplying additional information such as particle diameter concomitantly. These technologies have progressed to the stage of commercialization increasing the speed of viral titer measurements from hours to minutes, thus providing a significant advantage for many aspects of virology research and biotechnology applications. Additional advantages lie in the broad spectrum of virus species that may be measured and the possibility to determine the ratio of infectious to total particles. A series of disadvantages remain associated with these technologies, such as a low specificity for viral particles. In this review we will discuss these technologies by comparing four systems for real-time single virus particle analysis and quantification.

  8. Reducing stillbirths: prevention and management of medical disorders and infections during pregnancy

    PubMed Central

    Menezes, Esme V; Yakoob, Mohammad Yawar; Soomro, Tanya; Haws, Rachel A; Darmstadt, Gary L; Bhutta, Zulfiqar A

    2009-01-01

    Background An estimated two-thirds of the world's 3.2 million stillbirths occur antenatally, prior to labour, and are often overlooked in policy and programs. Poorly recognised, untreated or inadequately treated maternal infections such as syphilis and malaria, and maternal conditions including hypertensive disorders, are known risk factors for stillbirth. Methods We undertook a systematic review of the evidence for 16 antenatal interventions with the potential to prevent stillbirths. We searched a range of sources including PubMed and the Cochrane Library. For interventions with prior Cochrane reviews, we conducted additional meta-analyses including eligible newer randomised controlled trials following the Cochrane protocol. We focused on interventions deliverable at the community level in low-/middle-income countries, where the burden of stillbirths is greatest. Results Few of the studies we included reported stillbirth as an outcome; most that did were underpowered to assess this outcome. While Cochrane reviews or meta-analyses were available for many interventions, few focused on stillbirth or perinatal mortality as outcomes, and evidence was frequently conflicting. Several interventions showed clear evidence of impact on stillbirths, including heparin therapy for certain maternal indications; syphilis screening and treatment; and insecticide-treated bed nets for prevention of malaria. Other interventions, such as management of obstetric intrahepatic cholestasis, maternal anti-helminthic treatment, and intermittent preventive treatment of malaria, showed promising impact on stillbirth rates but require confirmatory studies. Several interventions reduced known risk factors for stillbirth (e.g., anti-hypertensive drugs for chronic hypertension), yet failed to show statistically significant impact on stillbirth or perinatal mortality rates. Periodontal disease emerged as a clear risk factor for stillbirth but no interventions have reduced stillbirth rates

  9. Carotenoid inhibitors reduce strigolactone production and Striga hermonthica infection in rice.

    PubMed

    Jamil, Muhammad; Charnikhova, Tatsiana; Verstappen, Francel; Bouwmeester, Harro

    2010-12-01

    The strigolactones are internal and rhizosphere signalling molecules in plants that are biosynthesised through carotenoid cleavage. They are secreted by host roots into the rhizosphere where they signal host-presence to the symbiotic arbuscular mycrorrhizal (AM) fungi and the parasitic plants of the Orobanche, Phelipanche and Striga genera. The seeds of these parasitic plants germinate after perceiving these signalling molecules. After attachment to the host root, the parasite negatively affects the host plant by withdrawing water, nutrients and assimilates through a direct connection with the host xylem. In many areas of the world these parasites are a threat to agriculture but so far very limited success has been achieved to minimize losses due to these parasitic weeds. Considering the carotenoid origin of the strigolactones, in the present study we investigated the possibilities to reduce strigolactone production in the roots of plants by blocking carotenoid biosynthesis using carotenoid inhibitors. Hereto the carotenoid inhibitors fluridone, norflurazon, clomazone and amitrole were applied to rice either through irrigation or through foliar spray. Irrigation application of all carotenoid inhibitors and spray application of amitrole significantly decreased strigolactone production, Striga hermonthica germination and Striga infection, also in concentrations too low to affect growth and development of the host plant. Hence, we demonstrate that the application of carotenoid inhibitors to plants can affect S. hermonthica germination and attachment indirectly by reducing the strigolactone concentration in the rhizosphere. This finding is useful for further studies on the relevance of the strigolactones in rhizosphere signalling. Since these inhibitors are available and accessible, they may represent an efficient technology for farmers, including poor subsistence farmers in the African continent, to control these harmful parasitic weeds.

  10. Is more better? Higher sterilization of infected hosts need not result in reduced pest population size.

    PubMed

    Maxin, Daniel; Berec, Luděk; Bingham, Adrienna; Molitor, Denali; Pattyson, Julie

    2015-05-01

    We analyze the effect of sterilization in the infected hosts in several epidemiological models involving infectious diseases that can be transmitted both vertically and horizontally. Sterilizing pathogens can be used as pest control agents by intentionally inoculating the target population, with the goal of reducing or eliminating it completely. Contrary to previous models that did not include vertical transmission we found that the population size at the endemic equilibrium may actually increase with higher levels of sterility. This effect is proved to exist for low to high efficiencies of vertical transmission. On the other hand, if the disease is sexually transmitted and the host reproduction and disease transmission are both consistently mediated by mating, we do not observe such a counter-intuitive effect and the population size in the stable endemic equilibrium is decreasing with higher levels of sterility. We suggest that models of the pest control techniques involving the release of sterilizing pathogens have to carefully consider the routes such pathogens use for transmission.

  11. The Use of Gentamicin-Impregnated Collagen Sponge for Reducing Surgical Site Infection after Spine Surgery

    PubMed Central

    Han, Jin-Sol; Jin, Sung-Won; Lee, Seung-Hwan; Kim, Bum-Joon; Kim, Sang-Dae; Lim, Dong-Jun

    2016-01-01

    Objective Surgical site infection (SSI) is the one of the most frequent complications in hospitalized patients, and it extends hospital stays and causes extra morbidities. To reduce SSI after spine surgery, we applied the gentamicin-impregnated collagen sponge (Collatamp G) during the operation and analyzed the results retrospectively. Methods Between October 2012 and December 2015, we collected data who applied the Collatamp G in spine surgery at a single institution. Demographic data of patients and another possible risk factors of SSI were also included, and we assessed the correlation between the risk factors and the developing of SSI by reviewing electronic medical records retrospectively. Results Three percent of all patients (10 of 280) developed the SSI and only 0.8% of patients who applied Collatamp G developed SSI (1 of 119). Otherwise, 5% of patients who did not apply Collatamp G developed SSI (9 of 161) (p=0.034). We also analyzed the correlation between SSI and other potential risk factors but nothings showed statistical correlation with SSI. Conclusion In this study, there were statistically significant results that SSI rate was decreased in the group of patients using Collatamp G in spine surgery generally. However, further studies are required to resolve some limitations in the future. PMID:27799992

  12. Enhancing Resident Safety by Preventing Healthcare-Associated Infection: A National Initiative to Reduce Catheter-Associated Urinary Tract Infections in Nursing Homes.

    PubMed

    Mody, Lona; Meddings, Jennifer; Edson, Barbara S; McNamara, Sara E; Trautner, Barbara W; Stone, Nimalie D; Krein, Sarah L; Saint, Sanjay

    2015-07-01

    Preventing healthcare-associated infection (HAI) is a key contributor to enhancing resident safety in nursing homes. In 2013, the U.S. Department of Health and Human Services approved a plan to enhance resident safety by reducing HAIs in nursing homes, with particular emphasis on reducing indwelling catheter use and catheter-associated urinary tract infection (CAUTI). Lessons learned from a recent multimodal Targeted Infection Prevention program in a group of nursing homes as well as a national initiative to prevent CAUTI in over 950 acute care hospitals called "On the CUSP: STOP CAUTI" will now be implemented in nearly 500 nursing homes in all 50 states through a project funded by the Agency for Healthcare Research and Quality (AHRQ). This "AHRQ Safety Program in Long-Term Care: HAIs/CAUTI" will emphasize professional development in catheter utilization, catheter care and maintenance, and antimicrobial stewardship as well as promoting patient safety culture, team building, and leadership engagement. We anticipate that an approach integrating technical and socio-adaptive principles will serve as a model for future initiatives to reduce other infections, multidrug resistant organisms, and noninfectious adverse events among nursing home residents. PMID:25814630

  13. Mutational analysis of the herpes simplex virus virion host shutoff protein: evidence that vhs functions in the absence of other viral proteins.

    PubMed

    Jones, F E; Smibert, C A; Smiley, J R

    1995-08-01

    Herpes simplex virus (HSV) virions contain one or more factors that trigger rapid shutoff of host protein synthesis and accelerated decay of cellular and viral mRNAs in infected cells. HSV isolates bearing mutations at the virion host shutoff (vhs) locus (gene UL41) are defective for both processes, indicating that the vhs protein is required; however, it is not clear whether the role of vhs in shutoff is direct or indirect and if other virion components are also necessary. We therefore used a transient-cotransfection assay to determine if the vhs protein displays activity in the absence of other viral gene products. We found that a vhs expression vector strongly suppressed expression of a cotransfected lacZ reporter gene and that this effect was eliminated by the vhs1 point mutation that abolishes virion-induced host shutoff during HSV infection. Further evidence for the biological relevance of the transfection assay came from the demonstration that five vhs in-frame linker insertion mutations yielded concordant results when assayed in cotransfected cells and following transfer into the viral genome: three mutations eliminated activity in both assays, while two had no effect. On the basis of these results, we conclude that the vhs protein can trigger host shutoff in the absence of other HSV proteins. The cotransfection assay was used to rapidly assess the activities of a panel of linker insertion mutants spanning the vhs polypeptide. All mutations that mapped to regions conserved among the vhs homologs of alphaherpesvirus inactivated function; in contrast, four of five mutations that mapped to regions that are absent from several vhs homologs had no effect. These results further support the biological relevance of the transfection assay and begin to delineate functional domains of the vhs polypeptide.

  14. Corneal replication is an interferon response-independent bottleneck for virulence of herpes simplex virus 1 in the absence of virion host shutoff.

    PubMed

    Pasieka, Tracy Jo; Menachery, Vineet D; Rosato, Pamela C; Leib, David A

    2012-07-01

    Herpes simplex viruses lacking the virion host shutoff function (Δvhs) are avirulent and hypersensitive to type I and type II interferon (IFN). In this study, we demonstrate that even in the absence of IFN responses in AG129 (IFN-αβγR(-/-)) mice, Δvhs remains highly attenuated via corneal infection but is fully virulent via intracranial infection. The data demonstrate that the interferon-independent inherent replication defect of Δvhs has a significant impact upon peripheral replication and neuroinvasion.

  15. Efficacy of Tenofovir 1% Vaginal Gel in Reducing the Risk of HIV-1 and HSV-2 Infection

    PubMed Central

    McConville, Christopher; Boyd, Peter; Major, Ian

    2014-01-01

    Human Immunodeficiency Virus (HIV) is a retrovirus that can result in rare opportunistic infections occurring in humans. The onset of these infections is known as Acquired Immune Deficiency Syndrome (AIDS). Sexual transmission is responsible for the majority of infections 1, resulting in transmission of HIV due to infected semen or vaginal and cervical secretions containing infected lymphocytes. HIV microbicides are formulations of chemical or biological agents that can be applied to the vagina or rectum with the intention of reducing the acquisition of HIV. Tenofovir is an NRTI that is phosphorylated by adenylate kinase to tenofovir diphosphate, which in turn competes with deoxyadeosine 5’-triphosphate for incorporation into newly synthesized HIV DNA. Once incorporated, tenofovir diphosphate results in chain termination, thus inhibiting viral replication. Tenofovir has been formulated into a range of vaginal formulations, such as rings, tablets gels and films. It has been shown to safe and effective in numerous animal models, while demonstrating safety and acceptability in numerous human trials. The most encouraging results came from the CAPRISA 004 clinical trial which demonstrated that a 1% Tenofovir vaginal gel reduced HIV infection by approximately 39%. PMID:24741339

  16. Cytomegalovirus Infection May Contribute to the Reduced Immune Function, Growth, Development, and Health of HIV-Exposed, Uninfected African Children

    PubMed Central

    Filteau, Suzanne; Rowland-Jones, Sarah

    2016-01-01

    With increasing access to antiretroviral therapy (ART) in Africa, most children born to HIV-infected mothers are not themselves HIV-infected. These HIV-exposed, uninfected (HEU) children are at increased risk of mortality and have immune, growth, development, and health deficits compared to HIV-unexposed children. HEU children are known to be at higher risk than HIV-unexposed children of acquiring cytomegalovirus (CMV) infection in early life. This risk is largely unaffected by ART and is increased by breastfeeding, which itself is critically important for child health and survival. Early CMV infection, namely in utero or during early infancy, may contribute to reduced growth, altered or impaired immune functions, and sensory and cognitive deficits. We review the evidence that CMV may be responsible for the health impairments of HEU children. There are currently no ideal safe and effective interventions to reduce postnatal CMV infection. If a clinical trial showed proof of the principle that decreasing early CMV infection improved health and development of HEU children, this could provide the impetus needed for the development of better interventions to improve the health of this vulnerable population. PMID:27446087

  17. Cytomegalovirus Infection May Contribute to the Reduced Immune Function, Growth, Development, and Health of HIV-Exposed, Uninfected African Children.

    PubMed

    Filteau, Suzanne; Rowland-Jones, Sarah

    2016-01-01

    With increasing access to antiretroviral therapy (ART) in Africa, most children born to HIV-infected mothers are not themselves HIV-infected. These HIV-exposed, uninfected (HEU) children are at increased risk of mortality and have immune, growth, development, and health deficits compared to HIV-unexposed children. HEU children are known to be at higher risk than HIV-unexposed children of acquiring cytomegalovirus (CMV) infection in early life. This risk is largely unaffected by ART and is increased by breastfeeding, which itself is critically important for child health and survival. Early CMV infection, namely in utero or during early infancy, may contribute to reduced growth, altered or impaired immune functions, and sensory and cognitive deficits. We review the evidence that CMV may be responsible for the health impairments of HEU children. There are currently no ideal safe and effective interventions to reduce postnatal CMV infection. If a clinical trial showed proof of the principle that decreasing early CMV infection improved health and development of HEU children, this could provide the impetus needed for the development of better interventions to improve the health of this vulnerable population. PMID:27446087

  18. Generation of transgenic cattle expressing human β-defensin 3 as an approach to reducing susceptibility to Mycobacterium bovis infection.

    PubMed

    Su, Feng; Wang, Yongsheng; Liu, Guanghui; Ru, Kun; Liu, Xin; Yu, Yuan; Liu, Jun; Wu, Yongyan; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2016-03-01

    Bovine tuberculosis results from infection with Mycobacterium bovis, a member of the Mycobacterium tuberculosis family. Worldwide, M. bovis infections result in economic losses in the livestock industry; cattle production is especially hard-hit by this disease. Generating M. bovis-resistant cattle may potentially mitigate the impact of this disease by reducing M. bovis infections. In this study, we used transgenic somatic cell nuclear transfer to generate cattle expressing the gene encoding human β-defensin 3 (HBD3), which confers resistance to mycobacteria in vitro. We first generated alveolar epithelial cells expressing HBD3 under the control of the bovine MUC1 promoter, and confirmed that these cells secreted HBD3 and possessed anti-mycobacterial capacity. We then generated and identified transgenic cattle by somatic cell nuclear transfer. The cleavage and blastocyst formation rates of genetically modified embryos provided evidence that monoclonal transgenic bovine fetal fibroblast cells have an integral reprogramming ability that is similar to that of normal cells. Five genetically modified cows were generated, and their anti-mycobacterial capacities were evaluated. Alveolar epithelial cells and macrophages from these cattle expressed higher levels of HBD3 protein compared with non-transgenic cells and possessed effective anti-mycobacterial capacity. These results suggest that the overall risk of M. bovis infection in transgenic cattle is efficiently reduced, and support the development of genetically modified animals as an effective tool to reduce M. bovis infection.

  19. Impact of reducing and oxidizing agents on the infectivity of Qβ phage and the overall structure of its capsid.

    PubMed

    Loison, Pauline; Majou, Didier; Gelhaye, Eric; Boudaud, Nicolas; Gantzer, Christophe

    2016-11-01

    Qβ phages infect Escherichia coli in the human gut by recognizing F-pili as receptors. Infection therefore occurs under reducing conditions induced by physiological agents (e.g. glutathione) or the intestinal bacterial flora. After excretion in the environment, phage particles are exposed to oxidizing conditions and sometimes disinfection. If inactivation does not occur, the phage may infect new hosts in the human gut through the oral route. During such a life cycle, we demonstrated that, outside the human gut, cysteines of the major protein capsid of Qβ phage form disulfide bonds. Disinfection with NaClO does not allow overoxidation to occur. Such oxidation induces inactivation rather by irreversible damage to the minor proteins. In the presence of glutathione, most disulfide bonds are reduced, which slightly increases the capacity of the phage to infect E. coli in vitro Such reduction is reversible and barely alters infectivity of the phage. Reduction of all disulfide bonds by dithiothreitol leads to complete capsid destabilization. These data provide new insights into how the phages are impacted by oxidizing-reducing conditions outside their host cell and raises the possibility of the intervention of the redox during life cycle of the phage. PMID:27402711

  20. Identification of bacteriophage virion proteins by the ANOVA feature selection and analysis.

    PubMed

    Ding, Hui; Feng, Peng-Mian; Chen, Wei; Lin, Hao

    2014-08-01

    The bacteriophage virion proteins play extremely important roles in the fate of host bacterial cells. Accurate identification of bacteriophage virion proteins is very important for understanding their functions and clarifying the lysis mechanism of bacterial cells. In this study, a new sequence-based method was developed to identify phage virion proteins. In the new method, the protein sequences were initially formulated by the g-gap dipeptide compositions. Subsequently, the analysis of variance (ANOVA) with incremental feature selection (IFS) was used to search for the optimal feature set. It was observed that, in jackknife cross-validation, the optimal feature set including 160 optimized features can produce the maximum accuracy of 85.02%. By performing feature analysis, we found that the correlation between two amino acids with one gap was more important than other correlations for phage virion protein prediction and that some of the 1-gap dipeptides were important and mainly contributed to the virion protein prediction. This analysis will provide novel insights into the function of phage virion proteins. On the basis of the proposed method, an online web-server, PVPred, was established and can be freely accessed from the website (http://lin.uestc.edu.cn/server/PVPred). We believe that the PVPred will become a powerful tool to study phage virion proteins and to guide the related experimental validations.

  1. Baicalin from Scutellaria baicalensis blocks respiratory syncytial virus (RSV) infection and reduces inflammatory cell infiltration and lung injury in mice

    PubMed Central

    Shi, Hengfei; Ren, Ke; Lv, Baojie; Zhang, Wei; Zhao, Ying; Tan, Ren Xiang; Li, Erguang

    2016-01-01

    The roots of Scutellaria baicalensis has been used as a remedy for inflammatory and infective diseases for thousands of years. We evaluated the antiviral activity against respiratory syncytial virus (RSV) infection, the leading cause of childhood infection and hospitalization. By fractionation and chromatographic analysis, we determined that baicalin was responsible for the antiviral activity of S. baicalensis against RSV infection. The concentration for 50% inhibition (IC50) of RSV infection was determined at 19.9 ± 1.8 μM, while the 50% cytotoxic concentration (CC50) was measured at 370 ± 10 μM. We then used a mouse model of RSV infection to further demonstrate baicalin antiviral effect. RSV infection caused significant lung injury and proinflammatory response, including CD4 and CD8 T lymphocyte infiltration. Baicalin treatment resulted in reduction of T lymphocyte infiltration and gene expression of proinflammatory factors, while the treatment moderately reduced RSV titers recovered from the lung tissues. T lymphocyte infiltration and cytotoxic T lymphocyte modulated tissue damage has been identified critical factors of RSV disease. The study therefore demonstrates that baicalin subjugates RSV disease through antiviral and anti-inflammatory effect. PMID:27767097

  2. Drought reduces chytrid fungus (Batrachochytrium dendrobatidis) infection intensity and mortality but not prevalence in adult crawfish frogs (Lithobates areolatus).

    PubMed

    Terrell, Vanessa C K; Engbrecht, Nathan J; Pessier, Allan P; Lannoo, Michael J

    2014-01-01

    To fully understand the impacts of the chytrid fungus Batrachochytrium dendrobatidis (Bd) on amphibians it is necessary to examine the interactions between populations and their environment. Ecologic variables can exacerbate or ameliorate Bd prevalence and infection intensity, factors that are positively related when Bd is acting on naive amphibian populations as an epidemic disease. In crawfish frogs (Lithobates areolatus), a North American species with a complex life history, we have shown that Bd acts as an endemic disease with impacts that vary seasonally; the highest infection prevalences and intensities and highest frog mortality occurred during late spring in postbreeding individuals. In this study, conducted between 28 February and 23 August 2011 in southwestern Indiana on the same population, we report an uncoupling of the previously observed relationship between Bd prevalence and intensity following an extreme drought. Specifically, there was a postdrought reduction in Bd infection intensity and mortality, but not in infection prevalence. This result suggests that the relationship between prevalence and intensity observed in Bd epidemics can be uncoupled in populations harboring endemic infections. Further, constant prevalence rates suggest either that crawfish frogs are being exposed to Bd sources independent of ambient moisture or that low-level infections below detection thresholds persist from year to year. Drought has several ecologically beneficial effects for amphibians with complex life histories, including eliminating fish and invertebrate populations that feed on larvae. To these ecologic benefits we suggest another, that drought can reduce the incidence of the severe skin disease (chytridiomycosis) due to Bd infection.

  3. A virus-encoded potassium ion channel is a structural protein in the chlorovirus Paramecium bursaria chlorella virus 1 virion

    PubMed Central

    Romani, Giulia; Piotrowski, Adrianna; Hillmer, Stefan; Gurnon, James; Van Etten, James L.; Moroni, Anna; Thiel, Gerhard

    2013-01-01

    Most chloroviruses encode small K+ channels, which are functional in electrophysiological assays. The experimental finding that initial steps in viral infection exhibit the same sensitivity to channel inhibitors as the viral K+ channels has led to the hypothesis that the channels are structural proteins located in the internal membrane of the virus particles. This hypothesis was questioned recently because proteomic studies failed to detect the channel protein in virions of the prototype chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1). Here, we used a mAb raised against the functional K+ channel from chlorovirus MA-1D to search for the viral K+ channel in the virus particle. The results showed that the antibody was specific and bound to the tetrameric channel on the extracellular side. The antibody reacted in a virus-specific manner with protein extracts from chloroviruses that encoded channels similar to that from MA-1D. There was no cross-reactivity with chloroviruses that encoded more diverse channels or with a chlorovirus that lacked a K+ channel gene. Together with electron microscopic imaging, which revealed labelling of individual virus particles with the channel antibody, these results establish that the viral particles contain an active K+ channel, presumably located in the lipid membrane that surrounds the DNA in the mature virions. PMID:23918407

  4. Incorporation of Hepatitis C Virus E1 and E2 Glycoproteins: The Keystones on a Peculiar Virion

    PubMed Central

    Vieyres, Gabrielle; Dubuisson, Jean; Pietschmann, Thomas

    2014-01-01

    Hepatitis C virus (HCV) encodes two envelope glycoproteins, E1 and E2. Their structure and mode of fusion remain unknown, and so does the virion architecture. The organization of the HCV envelope shell in particular is subject to discussion as it incorporates or associates with host-derived lipoproteins, to an extent that the biophysical properties of the virion resemble more very-low-density lipoproteins than of any virus known so far. The recent development of novel cell culture systems for HCV has provided new insights on the assembly of this atypical viral particle. Hence, the extensive E1E2 characterization accomplished for the last two decades in heterologous expression systems can now be brought into the context of a productive HCV infection. This review describes the biogenesis and maturation of HCV envelope glycoproteins, as well as the interplay between viral and host factors required for their incorporation in the viral envelope, in a way that allows efficient entry into target cells and evasion of the host immune response. PMID:24618856

  5. A virus-encoded potassium ion channel is a structural protein in the chlorovirus Paramecium bursaria chlorella virus 1 virion.

    PubMed

    Romani, Giulia; Piotrowski, Adrianna; Hillmer, Stefan; Gurnon, James; Van Etten, James L; Moroni, Anna; Thiel, Gerhard; Hertel, Brigitte

    2013-11-01

    Most chloroviruses encode small K(+) channels, which are functional in electrophysiological assays. The experimental finding that initial steps in viral infection exhibit the same sensitivity to channel inhibitors as the viral K(+) channels has led to the hypothesis that the channels are structural proteins located in the internal membrane of the virus particles. This hypothesis was questioned recently because proteomic studies failed to detect the channel protein in virions of the prototype chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1). Here, we used a mAb raised against the functional K(+) channel from chlorovirus MA-1D to search for the viral K(+) channel in the virus particle. The results showed that the antibody was specific and bound to the tetrameric channel on the extracellular side. The antibody reacted in a virus-specific manner with protein extracts from chloroviruses that encoded channels similar to that from MA-1D. There was no cross-reactivity with chloroviruses that encoded more diverse channels or with a chlorovirus that lacked a K(+) channel gene. Together with electron microscopic imaging, which revealed labelling of individual virus particles with the channel antibody, these results establish that the viral particles contain an active K(+) channel, presumably located in the lipid membrane that surrounds the DNA in the mature virions.

  6. Suboptimal inhibition of protease activity in human immunodeficiency virus type 1: Effects on virion morphogenesis and RNA maturation

    SciTech Connect

    Moore, Michael D.; Fu, William; Soheilian, Ferri; Nagashima, Kunio; Ptak, Roger G.; Pathak, Vinay K.; Hu, Wei-Shau

    2008-09-15

    Protease activity within nascently released human immunodeficiency virus type 1 (HIV-1) particles is responsible for the cleavage of the viral polyproteins Gag and Gag-Pol into their constituent parts, which results in the subsequent condensation of the mature conical core surrounding the viral genomic RNA. Concomitant with viral maturation is a conformational change in the packaged viral RNA from a loosely associated dimer into a more thermodynamically stable form. In this study we used suboptimal concentrations of two protease inhibitors, lopinavir and atazanavir, to study their effects on Gag polyprotein processing and on the properties of the RNA in treated virions. Analysis of the treated virions demonstrated that even with high levels of inhibition of viral infectivity (IC{sub 90}), most of the Gag and Gag-Pol polyproteins were processed, although slight but significant increases in processing intermediates of Gag were detected. Drug treatments also caused a significant increase in the proportion of viruses displaying either immature or aberrant mature morphologies. The aberrant mature particles were characterized by an electron-dense region at the viral periphery and an electron-lucent core structure in the viral center, possibly indicating exclusion of the genomic RNA from these viral cores. Intriguingly, drug treatments caused only a slight decrease in overall thermodynamic stability of the viral RNA dimer, suggesting that the dimeric viral RNA was able to mature in the absence of correct core condensation.

  7. Granulocyte colony-stimulating factor administration to HIV-infected subjects augments reduced leukotriene synthesis and anticryptococcal activity in neutrophils.

    PubMed Central

    Coffey, M J; Phare, S M; George, S; Peters-Golden, M; Kazanjian, P H

    1998-01-01

    Neutrophil (PMN) dysfunction occurs in HIV infection. Leukotrienes (LT) are mediators derived from the 5-lipoxygenase (5-LO) pathway that play a role in host defense and are synthesized by PMN. We investigated the synthesis of LT by PMN from HIV-infected subjects. There was a reduction (4.0+/-1.3% of control) in LT synthesis in PMN from HIV-infected compared with normal subjects. This was associated with reduced expression of 5-LO-activating protein (31.2+/-9.6% of normal), but not of 5-LO itself. Since HIV does not directly infect PMN, we considered that these effects were due to reduced release of cytokines, such as granulocyte colony-stimulating factor (G-CSF). We examined the effect of G-CSF treatment (300 microgram daily for 5 d) on eight HIV-infected subjects. PMN were studied in vitro before therapy (day 1) and on days 4 and 7. LTB4 synthesis was increased on day 4 of G-CSF treatment, and returned toward day 1 levels on day 7. 5-LO and 5-LO-activating protein expression were increased in parallel. As a functional correlate to this increase in PMN LT synthesis by G-CSF, we examined the effects on killing of Cryptococcus neoformans. Anticryptococcal activity of PMN from HIV-infected subjects was less than that of PMN from normal subjects. G-CSF treatment improved fungistatic activity of PMN. This increase in antifungal activity was attenuated by in vitro treatment with the LT synthesis inhibitor, MK-886. In conclusion, PMN from HIV-infected subjects demonstrate reduced 5-LO metabolism and antifungal activity in vitro, which was reversed by in vivo G-CSF therapy. PMID:9710433

  8. Effect of chlorhexidine bathing in preventing infections and reducing skin burden and environmental contamination: A review of the literature.

    PubMed

    Donskey, Curtis J; Deshpande, Abhishek

    2016-05-01

    Chlorhexidine bathing is effective in reducing levels of pathogens on skin. In this review, we examine the evidence that chlorhexidine bathing can prevent colonization and infection with health care-associated pathogens and reduce dissemination to the environment and the hands of personnel. The importance of education and monitoring of compliance with bathing procedures is emphasized in order to optimize chlorhexidine bathing in clinical practice.

  9. Supplemental Intravenous Crystalloid Administration Does Not Reduce the Risk of Surgical Wound Infection

    PubMed Central

    Kabon, Barbara; Akça, Ozan; Taguchi, Akiko; Nagele, Angelika; Jebadurai, Ratnaraj; Arkilic, Cem F.; Sharma, Neeru; Ahluwalia, Arundhathi; Galandiuk, Susan; Fleshman, James; Sessler, Daniel I.; Kurz, Andrea

    2005-01-01

    Wound perfusion and oxygenation are important determinants of the development of postoperative wound infections. Supplemental fluid administration significantly increases tissue oxygenation in surrogate wounds in the subcutaneous tissue of the upper arm in perioperative surgical patients. We tested the hypothesis that supplemental fluid administration during and after elective colon resections decreases the incidence of postoperative wound infections. Patients undergoing open colon resection were randomly assigned to small (n=124, 8 mL·kg-1·h-1) or large volume (n=129, 16-18 mL·kg-1·h-1) fluid management. Our major outcomes were two distinct criteria for diagnosis of surgical wound infections: 1) purulent exudate combined with a culture positive for pathogenic bacteria and 2) Center for Disease Control criteria for diagnosis of surgical wound infections. All wound infections diagnosed using either criterion by a blinded observer in the 15 days following surgery were considered in the analysis. Wound healing was evaluated with the ASEPSIS scoring system. Of the patients given small fluid administration, 14 had surgical wound infections; 11 given large fluid therapy had infections, P=0.46. ASEPSIS wound healing scores were similar in both groups: 7±16 (small volume) vs. 8±14 (large volume), P=0.70. Our results suggest that supplemental hydration in the range tested does not impact wound infection rate. PMID:16244030

  10. Phage therapy to reduce pre-proccessing Salmonella infections in market-weight swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of meat and meat products with foodborne pathogens is usually the result of the carcass coming in contact with the feces of an infected animal during processing. In the case of Salmonella, several recent studies have reported that pigs become rapidly infected with the organism during p...

  11. Lack of effect of feeding citrus by-products in reducing Salmonella in experimentally infected weanling pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the current research was to determine if feeding citrus by-products D’Limonene (DL) and citrus molasses (MOL) would reduce the concentration and prevalence of Salmonella in weanling pigs experimentally infected with Salmonella Typhimurium. Twenty crossbred weanling pigs (avg. BW = ...

  12. Uukuniemi Phlebovirus Assembly and Secretion Leave a Functional Imprint on the Virion Glycome

    PubMed Central

    Harvey, David J.; Bitto, David; Halldorsson, Steinar; Bonomelli, Camille; Edgeworth, Matthew; Scrivens, James H.; Huiskonen, Juha T.

    2014-01-01

    Uukuniemi virus (UUKV) is a model system for investigating the genus Phlebovirus of the Bunyaviridae. We report the UUKV glycome, revealing differential processing of the Gn and Gc virion glycoproteins. Both glycoproteins display poly-N-acetyllactosamines, consistent with virion assembly in the medial Golgi apparatus, whereas oligomannose-type glycans required for DC-SIGN-dependent cellular attachment are predominant on Gc. Local virion structure and the route of viral egress from the cell leave a functional imprint on the phleboviral glycome. PMID:24942574

  13. Didanosine reduces atevirdine absorption in subjects with human immunodeficiency virus infections.

    PubMed Central

    Morse, G D; Fischl, M A; Shelton, M J; Borin, M T; Driver, M R; DeRemer, M; Lee, K; Wajszczuk, C P

    1996-01-01

    Atevirdine is a nonnucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type 1 and is currently in phase II clinical trials. Atevirdine is most soluble at a pH of < 2, and therefore, normal gastric acidity is most likely necessary for optimal bioavailability. Because of the rapid development of resistance in vitro, atevirdine is being evaluated in combination with didanosine and/or zidovudine in both two- and three-drug combination regimens. To examine the influence of concurrent didanosine (buffered tablet formulation) on the disposition of atevirdine, 12 human immunodeficiency virus type 1-infected subjects (mean CD4+ cell count, 199 cells per mm3; range, 13 to 447 cells/mm3) participated in a three-way, partially randomized, crossover, single-dose study to evaluate the pharmacokinetics of didanosine and atevirdine when each drug was given alone (treatments A and B, respectively) versus concurrently (treatment C). Concurrent administration of didanosine and atevirdine significantly reduced the maximum concentration of atevirdine in serum from 3.45 +/- 2.8 to 0.854 +/- 0.33 microM (P = 0.004). Likewise, the mean atevirdine area under the concentration-time curve from 0 to 24 h after administration of the combination was reduced to 6.47 +/- 2.2 microM.h (P = 0.004) relative to a value of 11.3 +/- 4.8 microM.h for atevirdine alone. Atevirdine had no statistically significant effect on the pharmacokinetic parameters of didanosine. Concurrent administration of single doses of atevirdine and didanosine resulted in a markedly lower maximum concentration of atevirdine in serum and area under the concentration-time curve, with a minimal effect on the disposition of didanosine. It is unknown whether an interaction of similar magnitude would occur under steady-state conditions; thus, combination regimens which include both atevirdine and didanosine should be designed so that their administration times are separated. Since

  14. Which One Is Better to Reduce the Infection Rate, Early or Late Cranioplasty?

    PubMed Central

    Lee, Kyeong-Seok; Shim, Jai-Joon; Yoon, Seok-Mann; Doh, Jae-Won; Bae, Hack-Gun

    2016-01-01

    Objective Decompressive craniectomy is an effective therapy to relieve high intracranial pressure after acute brain damage. However, the optimal timing for cranioplasty after decompression is still controversial. Many authors reported that early cranioplasty may contribute to improve the cerebral blood flow and brain metabolism. However, despite all the advantages, there always remains a concern that early cranioplasty may increase the chance of infection. The purpose of this retrospective study is to investigate whether the early cranioplasty increase the infection rate. We also evaluated the risk factors of infection following cranioplasty. Methods We retrospectively examined the results of 131 patients who underwent cranioplasty in our institution between January 2008 and June 2015. We divided them into early (≤90 days) and late (>90 days after craniectomy) groups. We examined the risk factors of infection after cranioplasty. We analyzed the infection rate between two groups. Results There were more male patients (62%) than female (38%). The mean age was 49 years. Infection occurred in 17 patients (13%) after cranioplasty. The infection rate of early cranioplasty was lower than that of late cranioplasty (7% vs. 20%; p=0.02). Early cranioplasty, non-metal allograft materials, re-operation before cranioplasty and younger age were the significant factors in the infection rate after cranioplasty (p<0.05). Especially allograft was a significant risk factor of infection (odds ratio, 12.4; 95% confidence interval, 3.24–47.33; p<0.01). Younger age was also a significant risk factor of infection after cranioplasty by multivariable analysis (odds ratio, 0.96; 95% confidence interval, 0.96–0.99; p=0.02). Conclusion Early cranioplasty did not increase the infection rate in this study. The use of non-metal allograft materials influenced a more important role in infection in cranioplasty. Actually, timing itself was not a significant risk factor in multivariate analysis

  15. Which One Is Better to Reduce the Infection Rate, Early or Late Cranioplasty?

    PubMed Central

    Lee, Kyeong-Seok; Shim, Jai-Joon; Yoon, Seok-Mann; Doh, Jae-Won; Bae, Hack-Gun

    2016-01-01

    Objective Decompressive craniectomy is an effective therapy to relieve high intracranial pressure after acute brain damage. However, the optimal timing for cranioplasty after decompression is still controversial. Many authors reported that early cranioplasty may contribute to improve the cerebral blood flow and brain metabolism. However, despite all the advantages, there always remains a concern that early cranioplasty may increase the chance of infection. The purpose of this retrospective study is to investigate whether the early cranioplasty increase the infection rate. We also evaluated the risk factors of infection following cranioplasty. Methods We retrospectively examined the results of 131 patients who underwent cranioplasty in our institution between January 2008 and June 2015. We divided them into early (≤90 days) and late (>90 days after craniectomy) groups. We examined the risk factors of infection after cranioplasty. We analyzed the infection rate between two groups. Results There were more male patients (62%) than female (38%). The mean age was 49 years. Infection occurred in 17 patients (13%) after cranioplasty. The infection rate of early cranioplasty was lower than that of late cranioplasty (7% vs. 20%; p=0.02). Early cranioplasty, non-metal allograft materials, re-operation before cranioplasty and younger age were the significant factors in the infection rate after cranioplasty (p<0.05). Especially allograft was a significant risk factor of infection (odds ratio, 12.4; 95% confidence interval, 3.24–47.33; p<0.01). Younger age was also a significant risk factor of infection after cranioplasty by multivariable analysis (odds ratio, 0.96; 95% confidence interval, 0.96–0.99; p=0.02). Conclusion Early cranioplasty did not increase the infection rate in this study. The use of non-metal allograft materials influenced a more important role in infection in cranioplasty. Actually, timing itself was not a significant risk factor in multivariate analysis

  16. Herpes simplex virus 1 counteracts tetherin restriction via its virion host shutoff activity.

    PubMed

    Zenner, Helen L; Mauricio, Rui; Banting, George; Crump, Colin M

    2013-12-01

    The interferon-inducible membrane protein tetherin (Bst-2, or CD317) is an antiviral factor that inhibits enveloped virus release by cross-linking newly formed virus particles to the producing cell. The majority of viruses that are sensitive to tetherin restriction appear to be those that acquire their envelopes at the plasma membrane, although many viruses, including herpesviruses, envelope at intracellular membranes, and the effect of tetherin on such viruses has been less well studied. We investigated the tetherin sensitivity and possible countermeasures of herpes simplex virus 1 (HSV-1). We found that overexpression of tetherin inhibits HSV-1 release and that HSV-1 efficiently depletes tetherin from infected cells. We further show that the virion host shutoff protein (Vhs) is important for depletion of tetherin mRNA and protein and that removal of tetherin compensates for defects in replication and release of a Vhs-null virus. Vhs is known to be important for HSV-1 to evade the innate immune response in vivo. Taken together, our data suggest that tetherin has antiviral activity toward HSV-1 and that the removal of tetherin by Vhs is important for the efficient replication and dissemination of HSV-1.

  17. Herpes Simplex Virus 1 Counteracts Tetherin Restriction via Its Virion Host Shutoff Activity

    PubMed Central

    Zenner, Helen L.; Mauricio, Rui; Banting, George

    2013-01-01

    The interferon-inducible membrane protein tetherin (Bst-2, or CD317) is an antiviral factor that inhibits enveloped virus release by cross-linking newly formed virus particles to the producing cell. The majority of viruses that are sensitive to tetherin restriction appear to be those that acquire their envelopes at the plasma membrane, although many viruses, including herpesviruses, envelope at intracellular membranes, and the effect of tetherin on such viruses has been less well studied. We investigated the tetherin sensitivity and possible countermeasures of herpes simplex virus 1 (HSV-1). We found that overexpression of tetherin inhibits HSV-1 release and that HSV-1 efficiently depletes tetherin from infected cells. We further show that the virion host shutoff protein (Vhs) is important for depletion of tetherin mRNA and protein and that removal of tetherin compensates for defects in replication and release of a Vhs-null virus. Vhs is known to be important for HSV-1 to evade the innate immune response in vivo. Taken together, our data suggest that tetherin has antiviral activity toward HSV-1 and that the removal of tetherin by Vhs is important for the efficient replication and dissemination of HSV-1. PMID:24067977

  18. Epitope mapping of Aleutian mink disease parvovirus virion protein VP1 and 2.

    PubMed

    Costello, F; Steenfos, N; Jensen, K T; Christensen, J; Gottschalck, E; Holm, A; Aasted, B

    1999-04-01

    Six overlapping fragments of the Aleutian Mink Disease parvoVirus (AMDV) virion protein VP1 and 2 (VP1/2) gene were inserted into the expression vector pMAL-c2. Four of the clones carried large overlapping fragments covering the entire VP1/2 gene. The remaining two clones covered specifically chosen regions within the VP1/2 gene. Using a Western blotting detection system, sera from AMDV-infected mink were tested against the recombinant polypeptides. These studies showed reactions primarily directed against the two AMDV polypeptides ranging from amino acids 297 to 518. Weaker reactions against other regions of the VP1/2 were also observed. The small fusion protein designed to cover the presumed AMDV VP1/2 loop 4 was purified by affinity chromatography and used to develop solid-phase immunoassays. Twelve small synthetic peptides were constructed and used as inhibitors. A peptide covering amino acids S428 to T448 was shown to block the reactivity of a pool of positive mink sera, indicating the presence of one dominant linear epitope. PMID:10219758

  19. Oligomerization within virions and subcellular localization of human immunodeficiency virus type 1 integrase.

    PubMed

    Petit, C; Schwartz, O; Mammano, F

    1999-06-01

    Previous biochemical and genetic evidence indicated that the functional form of retroviral integrase protein (IN) is a multimer. A direct demonstration of IN oligomerization during the infectious cycle was, however, missing, due to the absence of a sensitive detection method. We describe here the generation of infectious human immunodeficiency virus type 1 (HIV-1) viral clones carrying IN protein tagged with highly antigenic epitopes. In this setting, we could readily visualize IN both in producer cells and in viral particles. More interestingly, we detected IN oligomers, the formation of which was dependent on disulfide bridges and took place inside virions. Additionally, expression of a tagged HIV-1 IN in the absence of other viral components resulted in almost exclusive nuclear accumulation of the protein. Mutation of a conserved cysteine in the proposed dimer interface determined the loss of viral infectivity, associated with a reduction of IN oligomer formation and the redistribution of the mutated protein in the nucleus and cytoplasm. Epitope tagging of HIV-1 IN expressed alone or in the context of a replication-competent viral clone provides powerful tools to validate debated issues on the implication of this enzyme in different steps of the viral cycle.

  20. Altering the motility of Trypanosoma cruzi with rabbit polyclonal anti-peptide antibodies reduces infection to susceptible mammalian cells.

    PubMed

    Finkelsztein, Eli J; Diaz-Soto, Juan C; Vargas-Zambrano, Juan C; Suesca, Elizabeth; Guzmán, Fanny; López, Manuel C; Thomas, M Carmen; Forero-Shelton, Manu; Cuellar, Adriana; Puerta, Concepción J; González, John M

    2015-03-01

    Trypanosoma cruzi's trypomastigotes are highly active and their incessant motility seems to be important for mammalian host cell infection. The kinetoplastid membrane protein-11 (KMP-11) is a protein expressed in all parasite stages, which induces a cellular and humoral immune response in the infected host, and is hypothesized to participate in the parasite's motility. An N-terminal peptide from KMP-11, termed K1 or TcTLE, induced polyclonal antibodies that inhibit parasitic invasion of Vero cells. The goal of this study was to evaluate the motility and infectivity of T. cruzi when exposed to polyclonal anti-TcTLE antibodies. Rabbits were immunized with TcTLE peptide along with FIS peptide as an immunomodulator. ELISA assay results showed that post-immunization sera contained high titers of polyclonal anti-TcTLE antibodies, which were also reactive against the native KMP-11 protein and live parasites as detected by immunofluorescence and flow cytometry assays. Trypomastigotes of T. cruzi were incubated with pre- or post-immunization sera, and infectivity to human astrocytes was assessed by Giemsa staining/light microscope and flow cytometry using carboxyfluorescein diacetate succinimidyl ester (CFSE) labeled parasites. T. cruzi infection in astrocytes decreased approximately by 30% upon incubation with post-immunization sera compared with pre-immunization sera. Furthermore, trypomastigotes were recorded by video microscopy and the parasite's flagellar speed was calculated by tracking the flagella. Trypomastigotes exposed to post-immunization sera had qualitative alterations in motility and significantly slower flagella (45.5 µm/s), compared with those exposed to pre-immunization sera (69.2 µm/s). In summary, polyclonal anti-TcTLE serum significantly reduced the parasite's flagellar speed and cell infectivity. These findings support that KMP-11 could be important for parasite motility, and that by targeting its N-terminal peptide infectivity can be reduced.

  1. Lipoxin Inhibits Fungal Uptake by Macrophages and Reduces the Severity of Acute Pulmonary Infection Caused by Paracoccidioides brasiliensis.

    PubMed

    Ribeiro, Laura R R; Loures, Flávio V; de Araújo, Eliseu F; Feriotti, Cláudia; Costa, Tânia A; Serezani, Carlos Henrique; Jancar, Sonia; Calich, Vera L G

    2015-01-01

    Cysteinyl leukotrienes (CysLTs) and lipoxins (LXs) are lipid mediators that control inflammation, with the former inducing and the latter inhibiting this process. Because the role played by these mediators in paracoccidioidomycosis was not investigated, we aimed to characterize the role of CysLT in the pulmonary infection developed by resistant (A/J) and susceptible (B10.A) mice. 48 h after infection, elevated levels of pulmonary LTC4 and LXA4 were produced by both mouse strains, but higher levels were found in the lungs of susceptible mice. Blocking the CysLTs receptor by MTL reduced fungal loads in B10.A, but not in A/J mice. In susceptible mice, MLT treatment led to reduced influx of PMN leukocytes, increased recruitment of monocytes, predominant synthesis of anti-inflammatory cytokines, and augmented expression of 5- and 15-lipoxygenase mRNA, suggesting a prevalent LXA4 activity. In agreement, MTL-treated macrophages showed reduced fungal burdens associated with decreased ingestion of fungal cells. Furthermore, the addition of exogenous LX reduced, and the specific blockade of the LX receptor increased the fungal loads of B10.A macrophages. This study showed for the first time that inhibition of CysLTs signaling results in less severe pulmonary paracoccidioidomycosis that occurs in parallel with elevated LX activity and reduced infection of macrophages.

  2. Lipoxin Inhibits Fungal Uptake by Macrophages and Reduces the Severity of Acute Pulmonary Infection Caused by Paracoccidioides brasiliensis

    PubMed Central

    Ribeiro, Laura R. R.; Loures, Flávio V.; de Araújo, Eliseu F.; Feriotti, Cláudia; Costa, Tânia A.; Serezani, Carlos Henrique; Jancar, Sonia; Calich, Vera L. G.

    2015-01-01

    Cysteinyl leukotrienes (CysLTs) and lipoxins (LXs) are lipid mediators that control inflammation, with the former inducing and the latter inhibiting this process. Because the role played by these mediators in paracoccidioidomycosis was not investigated, we aimed to characterize the role of CysLT in the pulmonary infection developed by resistant (A/J) and susceptible (B10.A) mice. 48 h after infection, elevated levels of pulmonary LTC4 and LXA4 were produced by both mouse strains, but higher levels were found in the lungs of susceptible mice. Blocking the CysLTs receptor by MTL reduced fungal loads in B10.A, but not in A/J mice. In susceptible mice, MLT treatment led to reduced influx of PMN leukocytes, increased recruitment of monocytes, predominant synthesis of anti-inflammatory cytokines, and augmented expression of 5- and 15-lipoxygenase mRNA, suggesting a prevalent LXA4 activity. In agreement, MTL-treated macrophages showed reduced fungal burdens associated with decreased ingestion of fungal cells. Furthermore, the addition of exogenous LX reduced, and the specific blockade of the LX receptor increased the fungal loads of B10.A macrophages. This study showed for the first time that inhibition of CysLTs signaling results in less severe pulmonary paracoccidioidomycosis that occurs in parallel with elevated LX activity and reduced infection of macrophages. PMID:26635449

  3. Bacterial Infection of Fly Ovaries Reduces Egg Production and Induces Local Hemocyte Activation

    PubMed Central

    Brandt, Stephanie M.; Schneider, David S.

    2009-01-01

    Summary Morbidity, the state of being diseased, is an important aspect of pathogenesis that has gone relatively unstudied in fruit flies. Our interest is in characterizing how bacterial pathogenesis affects various physiologies of the fly. We chose to examine the fly ovary because we found bacterial infection had a striking effect on fly reproduction. We observed decreased egg laying after bacterial infection that correlated with increased bacterial virulence. We also found that bacteria colonized the ovary in a previously undescribed manner; bacteria were found in the posterior of the ovary, adjacent to the lateral oviduct. This local infection in the ovary resulted in melanization and activation of the cellular immune response at the site of infection. PMID:17400292

  4. Formalin treatment of Trichondina sp. reduced Flavobacterium columnare infection in tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and protozoan Trichodina spp. are common pathogens of cultured fish. Recent studies on parasite-bacterium interaction show evidence that concurrent infections increase severity of some infectious diseases, especially bacterial diseases. The effect of parasite treat...

  5. DNA Polymerase in Virions of a Reptilian Type C Virus

    PubMed Central

    Twardzik, Daniel R.; Papas, Takis S.; Portugal, Frank H.

    1974-01-01

    A study was made of the DNA polymerase of reptilian type C virus isolated from Russell's viper spleen cells. Simultaneous detection experiments demonstrated the presence of 70S RNA and RNA-dependent DNA polymerase activity in reptilian type C virions. The endogenous activity was dependent on the addition of all four deoxynucleotide triphosphates and demonstrated an absolute requirement for a divalent cation. The reptilian viral DNA polymerase elutes from phosphocellulose at 0.22 M salt. In this respect, it is similar to the avian (avian myeloblastosis virus; AMV) viral enzyme but is different from the mammalian (Rauscher leukemia virus; RLV) viral enzyme which elutes at 0.4 M salt. The molecular weight of the viper DNA polymerase as estimated from glycerol gradient centrifugation is 109,000. It is a smaller enzyme than the AMV DNA polymerase (180,000 daltons) and somewhat larger than the RLV enzyme (70,000 daltons). A comparison of other properties of the type C reptilian DNA polymerase with the enzyme found in other type C oncogenic viruses is made. PMID:4129837

  6. Quantitative real-time single particle analysis of virions

    SciTech Connect

    Heider, Susanne; Metzner, Christoph

    2014-08-15

    Providing information about single virus particles has for a long time been mainly the domain of electron microscopy. More recently, technologies have been developed—or adapted from other fields, such as nanotechnology—to allow for the real-time quantification of physical virion particles, while supplying additional information such as particle diameter concomitantly. These technologies have progressed to the stage of commercialization increasing the speed of viral titer measurements from hours to minutes, thus providing a significant advantage for many aspects of virology research and biotechnology applications. Additional advantages lie in the broad spectrum of virus species that may be measured and the possibility to determine the ratio of infectious to total particles. A series of disadvantages remain associated with these technologies, such as a low specificity for viral particles. In this review we will discuss these technologies by comparing four systems for real-time single virus particle analysis and quantification. - Highlights: • We introduce four methods for virus particle-based quantification of viruses. • They allow for quantification of a wide range of samples in under an hour time. • The additional measurement of size and zeta potential is possible for some.

  7. Impaired immune responses following spinal cord injury lead to reduced ability to control viral infection

    PubMed Central

    Held, Katherine S.; Steward, Oswald; Blanc, Caroline; Lane, Thomas E.

    2016-01-01

    Spinal cord injuries disrupt central autonomic pathways that regulate immune function, and increasing evidence suggests that this may cause deficiencies in immune responses in people with spinal cord injuries. Here we analyze the consequences of spinal cord injury (SCI) on immune responses following experimental viral infection of mice. Female C57BL/6 mice received complete crush injuries at either thoracic level 3 (T3) or 9 (T9), and 1 week post-injury, injured mice and un-injured controls were infected with different dosages of mouse hepatitis virus (MHV, a positive-strand RNA virus). Following MHV infection, T3- and T9-injured mice exhibited increased mortality in comparison to un-injured and laminectomy controls. Infection at all dosages resulted in significantly higher viral titer in both T3- and T9-injured mice compared to un-injured controls. Investigation of anti-viral immune responses revealed impairment of cellular infiltration and effector functions in mice with SCI. Specifically, cell-mediated responses were diminished in T3-injured mice, as seen by reduction in virus-specific CD4+ T lymphocyte proliferation and IFN-γ production and decreased numbers of activated antigen presenting cells compared to infected un-injured mice. Collectively, these data indicate that the inability to control viral replication following SCI is not level dependent and that increased susceptibility to infection is due to suppression of both innate and adaptive immune responses. PMID:20832407

  8. Disease in a dynamic landscape: host behavior and wildfire reduce amphibian chytrid infection

    USGS Publications Warehouse

    Hossack, Blake R.; Lowe, Winsor H.; Ware, Joy L.; Corn, Paul Stephen

    2013-01-01

    Disturbances are often expected to magnify effects of disease, but these effects may depend on the ecology, behavior, and life history of both hosts and pathogens. In many ecosystems, wildfire is the dominant natural disturbance and thus could directly or indirectly affect dynamics of many diseases. To determine how probability of infection by the aquatic fungus Batrachochytrium dendrobatidis (Bd) varies relative to habitat use by individuals, wildfire, and host characteristics, we sampled 404 boreal toads (Anaxyrus boreas boreas) across Glacier National Park, Montana (USA). Bd causes chytridiomycosis, an emerging infectious disease linked with widespread amphibian declines, including the boreal toad. Probability of infection was similar for females and the combined group of males and juveniles. However, only 9% of terrestrial toads were infected compared to >30% of aquatic toads, and toads captured in recently burned areas were half as likely to be infected as toads in unburned areas. We suspect these large differences in infection reflect habitat choices by individuals that affect pathogen exposure and persistence, especially in burned forests where warm, arid conditions could limit Bd growth. Our results show that natural disturbances such as wildfire and the resulting diverse habitats can influence infection across large landscapes, potentially maintaining local refuges and host behaviors that facilitate evolution of disease resistance.

  9. Vaccinia virus temperature-sensitive mutants in the A28 gene produce non-infectious virions that bind to cells but are defective in entry

    SciTech Connect

    Turner, Peter C. Dilling, Bradley P.; Prins, Cindy; Cresawn, Steven G.; Moyer, Richard W.; Condit, Richard C.

    2007-09-15

    The vaccinia virus temperature-sensitive mutations Cts6 and Cts9 were mapped by marker rescue and DNA sequencing to the A28 gene. Cts6 and Cts9 contain an identical 2-bp deletion truncating the A28 protein and removing the fourth conserved cysteine near the C-terminus. Cts9 mutant virions produced at 40 deg. C were non-infectious and unable to cause cytopathic effect. However, the mutant A28 protein localized to purified mature virions (MV) at 31 deg. C and 40 deg. C. MV of Cts9 produced at 40 deg. C bound to cells but did not enter cells. Low pH treatment of Cts9-infected cells at 18 h p.i. failed to produce fusion from within at 40 deg. C, but gave fusion at 31 deg. C. Adsorption of Cts9 mutant virions to cells followed by low pH treatment showed a defect in fusion from without. The Cts9 phenotype suggests that the A28 protein is involved in both virus entry and cell-cell fusion, and supports the linkage between the two processes.

  10. A standardized protocol to reduce cerebrospinal fluid shunt infection: The Hydrocephalus Clinical Research Network Quality Improvement Initiative

    PubMed Central

    Kestle, John R. W.; Riva-Cambrin, Jay; Wellons, John C.; Kulkarni, Abhaya V.; Whitehead, William E.; Walker, Marion L.; Oakes, W. Jerry; Drake, James M.; Luerssen, Thomas G.; Simon, Tamara D.; Holubkov, Richard

    2011-01-01

    Object Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN). Methods The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation. Results Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19–3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43–14.41; p = 0.01) were associated with an increased risk of infection. Conclusions The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will

  11. Multi-Faceted Proteomic Characterization of Host Protein Complement of Rift Valley Fever Virus Virions and Identification of Specific Heat Shock Proteins, Including HSP90, as Important Viral Host Factors

    PubMed Central

    Nuss, Jonathan E.; Kehn-Hall, Kylene; Benedict, Ashwini; Costantino, Julie; Ward, Michael; Peyser, Brian D.; Retterer, Cary J.; Tressler, Lyal E.; Wanner, Laura M.; McGovern, Hugh F.; Zaidi, Anum; Anthony, Scott M.; Kota, Krishna P.; Bavari, Sina; Hakami, Ramin M.

    2014-01-01

    Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF. PMID:24809507

  12. Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

    PubMed

    Nuss, Jonathan E; Kehn-Hall, Kylene; Benedict, Ashwini; Costantino, Julie; Ward, Michael; Peyser, Brian D; Retterer, Cary J; Tressler, Lyal E; Wanner, Laura M; McGovern, Hugh F; Zaidi, Anum; Anthony, Scott M; Kota, Krishna P; Bavari, Sina; Hakami, Ramin M

    2014-01-01

    Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

  13. Fusion between perinuclear virions and the outer nuclear membrane requires the fusogenic activity of herpes simplex virus gB.

    PubMed

    Wright, Catherine C; Wisner, Todd W; Hannah, Brian P; Eisenberg, Roselyn J; Cohen, Gary H; Johnson, David C

    2009-11-01

    Herpesviruses cross nuclear membranes (NMs) in two steps, as follows: (i) capsids assemble and bud through the inner NM into the perinuclear space, producing enveloped virus particles, and (ii) the envelopes of these virus particles fuse with the outer NM. Two herpes simplex virus (HSV) glycoproteins, gB and gH (the latter, likely complexed as a heterodimer with gL), are necessary for the second step of this process. Mutants lacking both gB and gH accumulate in the perinuclear space or in herniations (membrane vesicles derived from the inner NM). Both gB and gH/gL are also known to act directly in fusing the virion envelope with host cell membranes during HSV entry into cells, i.e., both glycoproteins appear to function directly in different aspects of the membrane fusion process. We hypothesized that HSV gB and gH/gL also act directly in the membrane fusion that occurs during virus egress from the nucleus. Previous studies of the role of gB and gH/gL in nuclear egress involved HSV gB and gH null mutants that could potentially also possess gross defects in the virion envelope. Here, we produced recombinant HSV-expressing mutant forms of gB with single amino acid substitutions in the hydrophobic "fusion loops." These fusion loops are thought to play a direct role in membrane fusion by insertion into cellular membranes. HSV recombinants expressing gB with any one of four fusion loop mutations (W174R, W174Y, Y179K, and A261D) were unable to enter cells. Moreover, two of the mutants, W174Y and Y179K, displayed reduced abilities to mediate HSV cell-to-cell spread, and W174R and A261D exhibited no spread. All mutant viruses exhibited defects in nuclear egress, enveloped virions accumulated in herniations and in the perinuclear space, and fewer enveloped virions were detected on cell surfaces. These results support the hypothesis that gB functions directly to mediate the fusion between perinuclear virus particles and the outer NM.

  14. Species diversity reduces parasite infection through cross-generational effects on host abundance.

    PubMed

    Johnson, Pieter T J; Preston, Daniel L; Hoverman, Jason T; Henderson, Jeremy S; Paull, Sara H; Richgels, Katherine L D; Redmond, Miranda D

    2012-01-01

    With growing interest in the effects of biodiversity on disease, there is a critical need for studies that empirically identify the mechanisms underlying the diversity-disease relationship. Here, we combined wetland surveys of host community structure with mechanistic experiments involving a multi-host parasite to evaluate competing explanations for the dilution effect. Sampling of 320 wetlands in California indicated that snail host communities were strongly nested, with competent hosts for the trematode Ribeiroia ondatrae predominating in low-richness assemblages and unsuitable hosts increasingly present in more diverse communities. Moreover, competent host density was negatively associated with increases in snail species richness. These patterns in host community assembly support a key prerequisite underlying the dilution effect. Results of multigenerational mesocosm experiments designed to mimic field-observed community assemblages allowed us to evaluate the relative importance of host density and diversity in influencing parasite infection success. Increases in snail species richness (from one to four species) had sharply negative effects on the density of infected hosts (-90% reduction). However, this effect was indirect; competition associated with non-host species led to a 95% reduction in host density (susceptible host regulation), owing primarily to a reduction in host reproduction. Among susceptible hosts, there were no differences in infection prevalence as a function of community structure, indicating a lack of support for a direct effect of diversity on infection (encounter reduction). In monospecific conditions, higher initial host densities increased infection among adult hosts; however, compensatory reproduction in the low-density treatments equalized the final number of infected hosts by the next generation, underscoring the relevance of multigenerational studies in understanding the dilution effect. These findings highlight the role of

  15. ISG15 Is Upregulated in Respiratory Syncytial Virus Infection and Reduces Virus Growth through Protein ISGylation

    PubMed Central

    González-Sanz, Rubén; Mata, Manuel; Bermejo-Martín, Jesús; Álvarez, Amparo; Cortijo, Julio; Melero, José A.

    2016-01-01

    ABSTRACT Human respiratory syncytial virus (RSV), for which neither a vaccine nor an effective therapeutic treatment is currently available, is the leading cause of severe lower respiratory tract infections in children. Interferon-stimulated gene 15 (ISG15) is a ubiquitin-like protein that is highly increased during viral infections and has been reported to have an antiviral or a proviral activity, depending on the virus. Previous studies from our laboratory demonstrated strong ISG15 upregulation during RSV infection in vitro. In this study, an in-depth analysis of the role of ISG15 in RSV infection is presented. ISG15 overexpression and small interfering RNA (siRNA)-silencing experiments, along with ISG15 knockout (ISG15−/−) cells, revealed an anti-RSV effect of the molecule. Conjugation inhibition assays demonstrated that ISG15 exerts its antiviral activity via protein ISGylation. This antiviral activity requires high levels of ISG15 to be present in the cells before RSV infection. Finally, ISG15 is also upregulated in human respiratory pseudostratified epithelia and in nasopharyngeal washes from infants infected with RSV, pointing to a possible antiviral role of the molecule in vivo. These results advance our understanding of the innate immune response elicited by RSV and open new possibilities to control infections by the virus. IMPORTANCE At present, no vaccine or effective treatment for human respiratory syncytial virus (RSV) is available. This study shows that interferon-stimulated gene 15 (ISG15) lowers RSV growth through protein ISGylation. In addition, ISG15 accumulation highly correlates with the RSV load in nasopharyngeal washes from children, indicating that ISG15 may also have an antiviral role in vivo. These results improve our understanding of the innate immune response to RSV and identify ISG15 as a potential target for virus control. PMID:26763998

  16. Human CD8+ herpes simplex virus-specific cytotoxic T-lymphocyte clones recognize diverse virion protein antigens.

    PubMed Central

    Tigges, M A; Koelle, D; Hartog, K; Sekulovich, R E; Corey, L; Burke, R L

    1992-01-01

    The role of the HLA class I-restricted, CD8+, herpes simplex virus (HSV)-specific cytotoxic T lymphocytes (CTL) in the control of human HSV infections is controversial because previous reports suggest that a substantial portion of the antigen-specific lytic response is mediated by CD4+ cells. To address this question directly, we isolated HSV-specific CD8+ CTL clones from a patient with recurrent genital herpes. These CTL were cloned by coculturing responder peripheral blood mononuclear cells (PBMC) with phytohemagglutinin-stimulated PBMC that had been infected with live HSV-2 and then irradiated prior to the addition of responder cells. After 1 week, CTL were cloned by limiting dilution using phytohemagglutinin stimulation and allogeneic feeder PBMC. Seven clones were isolated; all seven clones were CD8+ CD4- CD3+ DRbright, six lysed only HSV-2-infected targets, and one lysed both HSV-1- and HSV-2-infected targets. Antigen presentation was restricted by two to three different HLA class I loci. To determine the antigens recognized by these HSV-specific CTL, target cells were infected with HSV in the presence of acyclovir, 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, or cycloheximide in a series of drug block/release protocols to limit the repertoire of viral gene expression to select transcriptional classes. Five of the clones exhibited a different pattern of cytotoxicity, suggesting that each recognized a distinct HSV antigen. One of the clones appears to be directed against an immediate-early antigen; six of the clones recognize virion proteins. Five of these clones recognized internal virion proteins that could be introduced into target cells by HSV infection in the absence of virus gene expression. Antigen specificity was further tested by using vaccinia virus vectors that express glycoproteins gD2 and gB2 or the tegument protein VP16. One clone lysed vaccinia virus/gD2-infected target cells; the remaining clones did not recognize any of these gene

  17. Vaccination with a Live Attenuated Cytomegalovirus Devoid of a Protein Kinase R Inhibitory Gene Results in Reduced Maternal Viremia and Improved Pregnancy Outcome in a Guinea Pig Congenital Infection Model

    PubMed Central

    Bierle, Craig J.; Swanson, Elizabeth C.; McVoy, Michael A.; Wang, Jian Ben; Al-Mahdi, Zainab; Geballe, Adam P.

    2015-01-01

    vaccination against virion proteins but have yielded disappointing results. The advent of bacterial artificial chromosome technologies has enabled engineering of recombinant cytomegaloviruses (CMVs) from which virus genome-encoded immune modulation genes have been deleted, toward the goal of developing a safe and potentially more efficacious live attenuated vaccine. Here we report the findings of studies of such a vaccine against congenital CMV infection based on a virus with a targeted deletion in gp145, a virus genome-encoded inhibitor of protein kinase R, using the guinea pig model of vertical CMV transmission. The deletion virus was attenuated for dissemination in immunocompromised guinea pigs but elicited ELISA and neutralizing responses. The vaccine conferred protection against maternal DNAemia and congenital transmission and resulted in reduced viral loads in newborn guinea pigs. These results provide support for future studies of attenuated CMV vaccines. PMID:26178990

  18. Highly diluted medication reduces parasitemia and improves experimental infection evolution by Trypanosoma cruzi

    PubMed Central

    2012-01-01

    Background There is no published information about the use of different protocols to administer a highly diluted medication. Evaluate the effect of different protocols for treatment with biotherapic T. cruzi 17 dH (BIOTTc17dH) on clinical/parasitological evolution of mice infected with T. cruzi-Y strain. Methods A blind, randomized controlled trial was performed twice, using 60 28-day-old male Swiss mice infected with T. cruzi-Y strain, in five treatment groups: CI - treated with a 7% ethanol-water solution, diluted in water (10 μL/mL) ad libitum; BIOTPI - treated with BIOTTc17dH in water (10 μL/mL) ad libitum during a period that started on the day of infection; BIOT4DI - treated with BIOTTc17dH in water (10 μL/mL) ad libitum beginning on the 4th day of infection; BIOT4-5–6 - treated with BIOTTc17dH by gavage (0.2 mL/ animal/day) on the 4th, 5th and 6th days after infection; BIOT7-8–9 - treated with BIOTTc17dH by gavage (0.2 mL/ animal/day) on the 7th, 8th and 9th days after infection. We evaluated: parasitemia; total parasitemia (Ptotal); maximum peak of parasites; prepatent period (PPP) - time from infection to detection of the parasite in blood; patent period (PP) - period when the parasitemia can be detected in blood; clinical aspects; and mortality. Results Parasitological parameters in the BIOTPI and mainly in the BIOT4PI group showed better evolution of the infection compared to the control group (CI), with lower Ptotal, lower maximum peak of parasites, higher PPP, lower PP and longer survival times. These animals showed stable body temperature and higher weight gain and water consumption, with more animals having normal-appearing fur for longer periods. In contrast, groups BIOT4-5–6 and BIOT7-8–9 showed worse evolution of the infection compared to the control group, considering both parasitological and clinical parameters. The correlation analysis combined with the other data from this study indicated that the prepatent period is the best

  19. Systemic resistance induced by Bacillus lipopeptides in Beta vulgaris reduces infection by the rhizomania disease vector Polymyxa betae.

    PubMed

    Desoignies, Nicolas; Schramme, Florence; Ongena, Marc; Legrève, Anne

    2013-05-01

    The control of rhizomania, one of the most important diseases of sugar beet caused by the Beet necrotic yellow vein virus, remains limited to varietal resistance. In this study, we investigated the putative action of Bacillus amylolequifaciens lipopeptides in achieving rhizomania biocontrol through the control of the virus vector Polymyxa betae. Some lipopeptides that are produced by bacteria, especially by plant growth-promoting rhizobacteria, have been found to induce systemic resistance in plants. We tested the impact of the elicitation of systemic resistance in sugar beet through lipopeptides on infection by P. betae. Lipopeptides were shown to effectively induce systemic resistance in both the roots and leaves of sugar beet, resulting in a significant reduction in P. betae infection. This article provides the first evidence that induced systemic resistance can reduce infection of sugar beet by P. betae.

  20. Evaluation of the maturation of individual Dengue virions with flow virometry.

    PubMed

    Zicari, Sonia; Arakelyan, Anush; Fitzgerald, Wendy; Zaitseva, Elena; Chernomordik, Leonid V; Margolis, Leonid; Grivel, Jean-Charles

    2016-01-15

    High-throughput techniques are needed to analyze individual virions to understand how viral heterogeneity translates into pathogenesis since in bulk analysis the individual characteristics of virions are lost. Individual Dengue virions (DENV) undergo a maturation that involves a proteolytic cleavage of prM precursor into virion-associated M protein. Here, using a new nanoparticle-based technology, "flow virometry", we compared the maturation of individual DENV produced by BHK-21 and LoVo cells. The latter lacks the furin-protease that mediates prM cleavage. We found that prM is present on about 50% of DENV particles produced in BHK-21 cells and about 85% of DENV virions produced in LoVo, indicating an increase in the fraction of not fully matured virions. Flow virometry allows us to quantify the number of fully mature particles in DENV preparations and proves to be a useful method for studying heterogeneity of the surface proteins of various viruses.

  1. Dextran Sulfate Suppression of Viruses in the HIV Family: Inhibition of Virion Binding to CD4+ Cells

    NASA Astrophysics Data System (ADS)

    Mitsuya, Hiroaki; Looney, David J.; Kuno, Sachiko; Ueno, Ryuji; Wong-Staal, Flossie; Broder, Samuel

    1988-04-01

    The first step in the infection of human T lymphocytes by human immunodeficiency virus type 1 (HIV-1) is attachment to the target cell receptor, the CD4 antigen. This step may be vulnerable to attack by antibodies, chemicals, or small peptides. Dextran sulfate (molecular weight approximately 8000), which has been given to patients as an anticoagulant or antilipemic agent for more than two decades, was found to block the binding of virions to various target T lymphocytes, inhibit syncytia formation, and exert a potent inhibitory effect against HIV-1 in vitro at concentrations that may be clinically attainable in human beings. This drug also suppressed the replication of HIV-2 in vitro. These observations could have theoretical and clinical implications in the strategy to develop drugs against HIV types 1 and 2.

  2. A Single-Nucleotide Synonymous Mutation in the gag Gene Controlling Human Immunodeficiency Virus Type 1 Virion Production▿

    PubMed Central

    Hamano, Takaichi; Matsuo, Kazuhiro; Hibi, Yurina; Victoriano, Ann Florence B.; Takahashi, Naoko; Mabuchi, Yosio; Soji, Tsuyoshi; Irie, Shinji; Sawanpanyalert, Pathom; Yanai, Hideki; Hara, Takashi; Yamazaki, Shudo; Yamamoto, Naoki; Okamoto, Takashi

    2007-01-01

    Viral factors as well as host ones play major roles in the disease progression of human immunodeficiency virus type 1 (HIV-1) infection. We have examined cytotoxic T-lymphocyte activity and HIV-1 DNA PCR results of 312 high-risk seronegative drug users in northern Thailand and identified four seronegative cases positive for both assays. Furthermore, we have identified a synonymous mutation in nucleotide position 75 of the gag p17 gene (A426G) of HIV-1 that belongs to the CRF01_AE virus circulating in Thailand. The replication-competent HIV-1 clone containing the A426G mutation demonstrated a dramatic reduction of virion production and perturbation of viral morphogenesis without affecting viral protein synthesis in cells. PMID:17121798

  3. Intrapatient sequence variation of the gag gene of human immunodeficiency virus type 1 plasma virions.

    PubMed Central

    Yoshimura, F K; Diem, K; Learn, G H; Riddell, S; Corey, L

    1996-01-01

    Because certain regions of the gag gene, such as p24, are highly conserved among human immunodeficiency virus (HIV) isolates, many therapeutic strategies have been directed at gag gene targets. Although intrapatient variation of segments of gag have been determined, little is known about the variability of the full-length gag gene for HIV isolated from a single individual. To evaluate intrapatient full-length gag variability, we derived the nucleotide sequences of at least 10 cDNA gag clones of virion RNA isolated from plasma for each of four asymptomatic HIV type 1-infected patients with relatively high CD4+ T-cell counts (300 to 450 cells per mm3). Mean values of intrapatient gag nucleotide variation obtained by pairwise comparisons ranged from 0.55 to 2.86%. For three subjects, this value was equivalent to that reported for intrapatient full-length env variation. The greatest range of intrapatient mean nucleotide variation for individual protein-coding regions was observed for p7. We did not detect any G-to-A hypermutation, as A-to-G and G-to-A transitions occurred at similar frequencies, accounting for 29 and 25%, respectively, of the changes. Mean variation values and phylogenetic analysis suggested that the extent of nucleotide variation correlated with the length of viral infection. Furthermore, no distinct subpopulations of quasispecies were detectable within an individual. The predicted amino acid sequences indicated that there were no regions within a gag protein that were comprised of clustered changes. PMID:8971017

  4. HIV Virions as Nanoscopic Test Tubes for Probing Oligomerization of the Integrase Enzyme

    PubMed Central

    2015-01-01

    Employing viruses as nanoscopic lipid-enveloped test tubes allows the miniaturization of protein–protein interaction (PPI) assays while preserving the physiological environment necessary for particular biological processes. Applied to the study of the human immunodeficiency virus type 1 (HIV-1), viral biology and pathology can also be investigated in novel ways, both in vitro as well as in infected cells. In this work we report on an experimental strategy that makes use of engineered HIV-1 viral particles, to allow for probing PPIs of the HIV-1 integrase (IN) inside viruses with single-molecule Förster resonance energy transfer (FRET) using fluorescent proteins (FP). We show that infectious fluorescently labeled viruses can be obtained and that the quantity of labels can be accurately measured and controlled inside individual viral particles. We demonstrate, with proper control experiments, the formation of IN oligomers in single viral particles and inside viral complexes in infected cells. Finally, we show a clear effect on IN oligomerization of small molecule inhibitors of interactions of IN with its natural human cofactor LEDGF/p75, corroborating that IN oligomer enhancing drugs are active already at the level of the virus and strongly suggesting the presence of a dynamic, enhanceable equilibrium between the IN dimer and tetramer in viral particles. Although applied to the HIV-1 IN enzyme, our methodology for utilizing HIV virions as nanoscopic test tubes for probing PPIs is generic, i.e., other PPIs targeted into the HIV-1, or PPIs targeted into other viruses, can potentially be studied with a similar strategy. PMID:24654558

  5. Noninfectious X4 but not R5 human immunodeficiency virus type 1 virions inhibit humoral immune responses in human lymphoid tissue ex vivo

    NASA Technical Reports Server (NTRS)

    Fitzgerald, Wendy; Sylwester, Andrew W.; Grivel, Jean-Charles; Lifson, Jeffrey D.; Margolis, Leonid B.

    2004-01-01

    Ex vivo human immunodeficiency virus type 1 (HIV-1) infection of human lymphoid tissue recapitulates some aspects of in vivo HIV-1 infection, including a severe depletion of CD4(+) T cells and suppression of humoral immune responses to recall antigens or to polyclonal stimuli. These effects are induced by infection with X4 HIV-1 variants, whereas infection with R5 variants results in only mild depletion of CD4(+) T cells and no suppression of immune responses. To study the mechanisms of suppression of immune responses in this ex vivo system, we used aldrithiol-2 (AT-2)-inactivated virions that have functional envelope glycoproteins but are not infectious and do not deplete CD4(+) T cells in human lymphoid tissues ex vivo. Nevertheless, AT-2-inactivated X4 (but not R5) HIV-1 virions, even with only a brief exposure, inhibit antibody responses in human lymphoid tissue ex vivo, similarly to infectious virus. This phenomenon is mediated by soluble immunosuppressive factor(s) secreted by tissue exposed to virus.

  6. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen

    PubMed Central

    Savage, Anna E.; Terrell, Kimberly A.; Gratwicke, Brian; Mattheus, Nichole M.; Augustine, Lauren; Fleischer, Robert C.

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1–15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29–55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations. PMID:27293759

  7. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen.

    PubMed

    Savage, Anna E; Terrell, Kimberly A; Gratwicke, Brian; Mattheus, Nichole M; Augustine, Lauren; Fleischer, Robert C

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1-15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29-55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations.

  8. Reduced immune function predicts disease susceptibility in frogs infected with a deadly fungal pathogen.

    PubMed

    Savage, Anna E; Terrell, Kimberly A; Gratwicke, Brian; Mattheus, Nichole M; Augustine, Lauren; Fleischer, Robert C

    2016-01-01

    The relationship between amphibian immune function and disease susceptibility is of primary concern given current worldwide declines linked to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We experimentally infected lowland leopard frogs (Lithobates yavapaiensis) with Bd to test the hypothesis that infection causes physiological stress and stimulates humoral and cell-mediated immune function in the blood. We measured body mass, the ratio of circulating neutrophils to lymphocytes (a known indicator of physiological stress) and plasma bacterial killing ability (BKA; a measure of innate immune function). In early exposure (1-15 days post-infection), stress was elevated in Bd-positive vs. Bd-negative frogs, whereas other metrics were similar between the groups. At later stages (29-55 days post-infection), stress was increased in Bd-positive frogs with signs of chytridiomycosis compared with both Bd-positive frogs without disease signs and uninfected control frogs, which were similar to each other. Infection decreased growth during the same period, demonstrating that sustained resistance to Bd is energetically costly. Importantly, BKA was lower in Bd-positive frogs with disease than in those without signs of chytridiomycosis. However, neither group differed from Bd-negative control frogs. The low BKA values in dying frogs compared with infected individuals without disease signs suggests that complement activity might signify different immunogenetic backgrounds or gene-by-environment interactions between the host, Bd and abiotic factors. We conclude that protein complement activity might be a useful predictor of Bd susceptibility and might help to explain differential disease outcomes in natural amphibian populations. PMID:27293759

  9. Ivermectin Treatment and Sanitation Effectively Reduce Strongyloides stercoralis Infection Risk in Rural Communities in Cambodia

    PubMed Central

    Forrer, Armelle; Khieu, Virak; Schindler, Christian; Schär, Fabian; Marti, Hanspeter; Char, Meng Chuor; Muth, Sinuon; Odermatt, Peter

    2016-01-01

    Background Strongyloides stercoralis is the only soil-transmitted helminth with the ability to replicate within its host, leading to long-lasting and potentially fatal infections. It is ubiquitous and its worldwide prevalence has recently been estimated to be at least half that of hookworm. Information on the epidemiology of S. stercoralis remains scarce and modalities for its large-scale control are yet to be determined. Methodology/Principal Findings A community-based two-year cohort study was conducted among the general population in a rural province in North Cambodia. At each survey, participants infected with S. stercoralis were treated with a single oral dose of ivermectin (200μg/kg BW). Diagnosis was performed using a combination of the Baermann method and Koga agar plate culture on two stool samples. The cohort included participants from eight villages who were either positive or negative for S. stercoralis at baseline. Mixed logistic regression models were employed to assess risk factors for S. stercoralis infection at baseline and re-infection at follow-up. A total of 3,096 participants were examined at baseline, revealing a S. stercoralis prevalence of 33.1%. Of these participants, 1,269 were followed-up over two years. Re-infection and infection rates among positive and negative participants at baseline were 14.4% and 9.6% at the first and 11.0% and 11.5% at the second follow-up, respectively. At follow-up, all age groups were at similar risk of acquiring an infection, while infection risk significantly decreased with increasing village sanitation coverage. Conclusions/Significance Chemotherapy-based control of S. stercoralis is feasible and highly beneficial, particularly in combination with improved sanitation. The impact of community-based ivermectin treatment on S. stercoralis was high, with over 85% of villagers remaining negative one year after treatment. The integration of S. stercoralis into existing STH control programs should be considered

  10. Enalapril in Combination with Benznidazole Reduces Cardiac Inflammation and Creatine Kinases in Mice Chronically Infected with Trypanosoma cruzi.

    PubMed

    Penitente, Arlete Rita; Leite, Ana Luísa Junqueira; de Paula Costa, Guilherme; Shrestha, Deena; Horta, Aline Luciano; Natali, Antônio J; Neves, Clóvis A; Talvani, Andre

    2015-11-01

    The protozoan Trypanosoma cruzi triggers an inflammatory process in mammalian heart causing events such as fibrosis, changes in the architecture and functionality in this organ. Enalapril, an angiotensin II-converting enzyme inhibitor, is a drug prescribed to ameliorate this heart dysfunction, and appears to exert a potential role in immune system regulation. Our aim was to evaluate the chronic cardiac inflammatory parameters after therapeutic treatment with enalapril and benznidazole in C57BL/6 mice infected with the VL-10 strain of T. cruzi. After infection, animals were treated with oral doses of enalapril (25 mg/kg), benznidazole (100 mg/kg), or both during 30 days. Morphometric parameters and levels of chemokines (CCL2, CCL5), IL-10, creatine kinases (CKs), and C-reactive protein were evaluated in the heart and serum at the 120th day of infection. Enalapril alone or in combination with benznidazole did not change the number of circulating parasites, but reduced cardiac leukocyte recruitment and total collagen in the cardiac tissue. Interestingly, the combination therapy (enalapril/benznidazole) also reduced the levels of chemokines, CK and CK-MB, and C-reactive proteins in chronic phase. In conclusion, during the chronic experimental T. cruzi infection, the combination therapy using enalapril plus benznidazole potentiated their immunomodulatory effects, resulting in a low production of biomarkers of cardiac lesions. PMID:26350447

  11. Outcomes of a Pilot Hand Hygiene Randomized Cluster Trial to Reduce Communicable Infections Among US Office-Based Employees

    PubMed Central

    DuBois, Cathy L.Z.; Grey, Scott F.; Kingsbury, Diana M.; Shakya, Sunita; Scofield, Jennifer; Slenkovich, Ken

    2015-01-01

    Objective: To determine the effectiveness of an office-based multimodal hand hygiene improvement intervention in reducing self-reported communicable infections and work-related absence. Methods: A randomized cluster trial including an electronic training video, hand sanitizer, and educational posters (n = 131, intervention; n = 193, control). Primary outcomes include (1) self-reported acute respiratory infections (ARIs)/influenza-like illness (ILI) and/or gastrointestinal (GI) infections during the prior 30 days; and (2) related lost work days. Incidence rate ratios calculated using generalized linear mixed models with a Poisson distribution, adjusted for confounders and random cluster effects. Results: A 31% relative reduction in self-reported combined ARI-ILI/GI infections (incidence rate ratio: 0.69; 95% confidence interval, 0.49 to 0.98). A 21% nonsignificant relative reduction in lost work days. Conclusions: An office-based multimodal hand hygiene improvement intervention demonstrated a substantive reduction in self-reported combined ARI-ILI/GI infections. PMID:25719534

  12. Ciprofloxacin-loaded keratin hydrogels reduce infection and support healing in a porcine partial-thickness thermal burn.

    PubMed

    Roy, Daniel C; Tomblyn, Seth; Isaac, Kameel M; Kowalczewski, Christine J; Burmeister, David M; Burnett, Luke R; Christy, Robert J

    2016-07-01

    Infection is a leading cause of morbidity and mortality in burn patients. Current therapies include silver-based creams and dressings, which display limited antimicrobial effectiveness and impair healing. The need exists for a topical, point-of-injury antibiotic treatment that provides sustained antimicrobial activity without impeding wound repair. Fitting this description are keratin-based hydrogels, which are fully biocompatible and support the slow-release of antibiotics. Here we develop a porcine model of an infected partial-thickness burn to test the effects of ciprofloxacin-loaded keratin hydrogels on infection and wound healing. Partial-thickness burns were inoculated with either Pseudomonas aeruginosa or Methicillin-resistant Staphylococcus aureus, resulting in infections that persisted for >2 weeks that exceeded 10(5) and 10(6) cfu per gram of tissue, respectively. Compared to silver sulfadiazine, ciprofloxacin-loaded keratin hydrogel treatment significantly reduced the amount of P. aeruginosa and S. aureus in the burn by >99% on days 4, 7, 11, and 15 postinjury. Further, burns treated with ciprofloxacin-loaded keratin hydrogels exhibited similar healing patterns as uninfected burns with regards to reepithelialization, macrophage recruitment, and collagen deposition and remodeling. The ability of keratin hydrogels to deliver antibiotics to fight infection and support healing of partial-thickness burns make them a strong candidate as a first-line burn therapy. PMID:27238250

  13. IL-13 is associated with reduced illness and replication in primary respiratory syncytial virus infection in the mouse

    PubMed Central

    Zhou, Weisong; Hashimoto, Koichi; Moore, Martin L.; Elias, Jack A.; Zhu, Zhou; Durbin, Joan; Colasurdo, Giuseppe; Rutigliano, John A.; Chiappetta, Constance L.; Goleniewska, Kasia; O’Neal, Jamye F.; Graham, Barney S.; Peebles, R. Stokes

    2007-01-01

    The role of IL-13 in respiratory syncytial virus (RSV) immunopathogenesis is incompletely described. To assess the effect of IL-13 on primary RSV infection, transgenic mice which either overexpress IL-13 in the lung (IL-13 OE) or nontransgenic littermates (IL-13 NT) were challenged intranasally with RSV. IL-13 OE mice had significantly decreased peak viral titers four days after infection compared to non-transgenic littermates. In addition, the IL-13 OE mice had significantly lower RSV-induced weight loss and reduced lung IFN-γ protein expression compared with IL-13 NT mice. In contrast, primary RSV challenge of IL-13 deficient mice resulted in a small, but statistically significant increase in viral titers on day four after infection, no difference in RSV-induced weight loss compared to wild type mice, and augmented IFN-γ production on day 6 after infection. In STAT1-deficient (STAT1 KO) mice, where primary RSV challenge produced high levels of IL-13 production in the lungs, treatment with an IL-13 neutralizing protein resulted in greater peak viral titers both four and six days after RSV and greater RSV-induced weight loss compared to mice treated with a control protein. These results suggest that IL-13 modulates illness from RSV-infection. PMID:17110149

  14. Inhibition of caspase-8 activity reduces IFN-gamma expression by T cells from Leishmania major infection.

    PubMed

    Pereira, Wânia F; Guillermo, Landi V C; Ribeiro-Gomes, Flávia L; Lopes, Marcela F

    2008-03-01

    Following infection with Leishmania major, T cell activation and apoptosis can be detected in draining lymph nodes of C57BL/6-infected mice. We investigated the mechanisms involved in apoptosis and cytokine expression following T cell activation. After two weeks of infection, apoptotic T cells were not detected in draining lymph nodes but activation with anti-CD3 induced apoptosis in both CD4 and CD8 T cells. Treatment with anti-Fas Ligand, caspase-8 or caspase- 9 inhibitors did not block activation-induced T-cell death. We also investigated whether the blockade of caspase-8 activity would affect the expression of type-1 or type-2 cytokines. At early stages of infection, both CD4 and CD8 T cells expressed IFN-gamma upon activation. Treatment with the caspase-8 inhibitor zIETD-fmk (benzyl-oxycarbonyl-Ile- Glu(OMe)-Thr-Asp(OMe)-fluoromethyl ketone) reduced the proportion of CD8 T cells and IFN-gamma expression in both CD4 and CD8 T cells. We conclude that a non apoptotic role of caspase-8 activity may be required for T cell-mediated type-1 responses during L. major infection.

  15. A practical online tool to estimate antiretroviral coverage for HIV infected and susceptible populations needed to reduce local HIV epidemics

    PubMed Central

    Chaillon, Antoine; Hoenigl, Martin; Mehta, Sanjay R.; Weibel, Nadir; Little, Susan J.; Smith, Davey M.

    2016-01-01

    It remains unclear what proportions of HIV-infected and uninfected people should receive effective antiretroviral therapy (ART) to control local HIV epidemics. We developed a flexible model to evaluate the impact of treatment as prevention (TasP) and pre-exposure prophylaxis (PrEP) on HIV incidence in local communities. We evaluated this tool for determining what TasP and PrEP targets are needed to substantially reduce the HIV epidemic in San Diego, which is predominately comprised of men who have sex with men. By increasing the proportion of HIV-infected individuals on ART from 30% to 50%, 686 new infections would be prevented over five years in San Diego. By providing PrEP to 30% of MSM to the age group that account for 90% of local HIV incident cases (21–52 years), we could prevent 433 infections over five years. When combining these initiatives, a PrEP coverage rate of 40% and TasP coverage rate of 34% would be expected to decrease the number of new infections by over half in one year. This online tool is designed to help local public health planners and policy makers to estimate program outcomes and costs that may lead to better control of their local HIV epidemics. PMID:27337983

  16. Purification of Theiler's murine encephalomyelitis virus and analysis of the structural virion polypeptides: correlation of the polypeptide profile with virulence.

    PubMed

    Lipton, H L; Friedmann, A

    1980-03-01

    Theiler's murine encephalomyelitis viruses (TMEV) are separable into two groups based on their biological behavior: those highly virulent isolates which are unable to cause persistent infection and the less virulent isolates which regularly produce persistent central nervous system infection in mice. Two highly virulent and five less virulent TMEV were found to have the same buoyant density (1.34 g/ml) on isopycnic centrifugation and virion structure by electron microscopy. Negatively stained virus particles purified in Cs(2)SO(4) gradients appeared to have icosahedral symmetry and measured 28 nm in diameter. Mature virions were found to possess three major structural polypeptides, VP1, VP2 and VP3, in the range of 25,000 to 35,000 daltons, and a smaller fourth major polypeptide, VP4, of 6,000 daltons on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The precursor of VP2 and VP4, VP0, which is a minor polypeptide of mature picornavirus particles, was also identified. However, a slight but consistent difference in several of the capsid polypeptides between the highly virulent and less virulent TMEV was found. VP1 was slightly larger (34,000 versus 33,500 daltons) and VP2 was slightly smaller (31,000 versus 32,000 daltons) for the highly virulent strains compared to the same polypeptide species in the less virulent viruses. VP0 was also slightly smaller (35,500 versus 36,000 daltons) for the highly virulent isolates compared to their less virulent counterparts. Finally, trypsin which was used initially in our purification procedure resulted in preferential cleavage of a 2,000-molecular-weight fragment or fragments from VP1 of only the less virulent isolates.

  17. Purification of Theiler's Murine Encephalomyelitis Virus and Analysis of the Structural Virion Polypeptides: Correlation of the Polypeptide Profile with Virulence

    PubMed Central

    Lipton, Howard L.; Friedmann, Adam

    1980-01-01

    Theiler's murine encephalomyelitis viruses (TMEV) are separable into two groups based on their biological behavior: those highly virulent isolates which are unable to cause persistent infection and the less virulent isolates which regularly produce persistent central nervous system infection in mice. Two highly virulent and five less virulent TMEV were found to have the same buoyant density (1.34 g/ml) on isopycnic centrifugation and virion structure by electron microscopy. Negatively stained virus particles purified in Cs2SO4 gradients appeared to have icosahedral symmetry and measured 28 nm in diameter. Mature virions were found to possess three major structural polypeptides, VP1, VP2 and VP3, in the range of 25,000 to 35,000 daltons, and a smaller fourth major polypeptide, VP4, of 6,000 daltons on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The precursor of VP2 and VP4, VP0, which is a minor polypeptide of mature picornavirus particles, was also identified. However, a slight but consistent difference in several of the capsid polypeptides between the highly virulent and less virulent TMEV was found. VP1 was slightly larger (34,000 versus 33,500 daltons) and VP2 was slightly smaller (31,000 versus 32,000 daltons) for the highly virulent strains compared to the same polypeptide species in the less virulent viruses. VP0 was also slightly smaller (35,500 versus 36,000 daltons) for the highly virulent isolates compared to their less virulent counterparts. Finally, trypsin which was used initially in our purification procedure resulted in preferential cleavage of a 2,000-molecular-weight fragment or fragments from VP1 of only the less virulent isolates. Images PMID:6245266

  18. Acyclovir Prophylaxis Reduces the Incidence of Herpes Zoster Among HIV-Infected Individuals: Results of a Randomized Clinical Trial.

    PubMed

    Barnabas, Ruanne V; Baeten, Jared M; Lingappa, Jairam R; Thomas, Katherine K; Hughes, James P; Mugo, Nelly R; Delany-Moretlwe, Sinead; Gray, Glenda; Rees, Helen; Mujugira, Andrew; Ronald, Allan; Stevens, Wendy; Kapiga, Saidi; Wald, Anna; Celum, Connie

    2016-02-15

    Human immunodeficiency virus (HIV)-infected persons have higher rates of herpes zoster than HIV-uninfected individuals. We assessed whether twice daily treatment with 400 mg of oral acyclovir reduces the incidence of herpes zoster in a randomized, double-blind, placebo-controlled trial among 3408 persons coinfected with HIV and herpes simplex virus type 2. During 5175 person-years of follow-up, 26 cases of herpes zoster occurred among those assigned acyclovir, compared with 69 cases among those assigned placebo (rates, 1.00 and 2.68/100 person-years, respectively), a relative decrease of 62% (hazard ratio, 0.38; 95% confidence interval, .24-.67; P < .001). Daily acyclovir prophylaxis significantly reduced herpes zoster incidence among HIV-infected persons.

  19. Infection.

    PubMed

    Miclau, Theodore; Schmidt, Andrew H; Wenke, Joseph C; Webb, Lawrence X; Harro, Janette M; Prabhakara, Ranjani; Shirtliff, Mark E

    2010-09-01

    Musculoskeletal infection is a clinical problem with significant direct healthcare costs. The prevalence of infection after closed, elective surgery is frequently estimated to be less than 2%, but in severe injuries, posttraumatic infection rates have been reported as 10% or greater. Although clinical infections are found outside the realm of medical devices, it is clear that the enormous increase of infections associated with the use of implants presents a major challenge worldwide. This review summarizes recent advances in the understanding, diagnosis, and treatment of musculoskeletal infections.

  20. Ha-VP39 binding to actin and the influence of F-actin on assembly of progeny virions.

    PubMed

    Lu, S; Ge, G; Qi, Y

    2004-11-01

    We present evidence that actin is necessary for the successful assembly of HaNPV virions. Purified nucleocapsid protein Ha-VP39 of Heliothis armigera nuclear polyhedrosis virus (HaNPV) was found to be able to bind to actin in vitro without assistance, as demonstrated by Western blot and isothermal titration calorimeter. DeltaH and binding constants (K) detected by isothermal titration calorimeter strongly suggested that Ha-VP39 first binds actin to seed the formation of hexamer complex of actin, and the hexamers then link to each other to form filaments, and the filaments finally twist into cable structures. The proliferation of HaNPV was completely inhibited in Hz-AM1 cells cultivated in the medium containing 0.5 microg/ml cytochalasin D (CD) to prevent polymerization of actin, while its yield was reduced to 10(-4) in the presence of 0.1 microg/ml CD. Actin concentration and the viral DNA synthesis were not significantly affected by CD even though the progeny virions assembled in the CD treated cells were morphologically different from normal ones and resulted in fewer plaques in plaque assay.

  1. Filter-feeding bivalves can remove avian influenza viruses from water and reduce infectivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) viruses are transmitted within wild aquatic bird populations through an indirect fecal-oral route involving fecal-contaminated water. In this study, the influence of filter-feeding bivalves, Corbicula fluminea, on the infectivity of AI virus in water was examined. A single cla...

  2. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections.

    PubMed

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-06-24

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  3. Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

    PubMed Central

    Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

    2014-01-01

    Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor. PMID:25032095

  4. A Systematic Review of Interventions to Reduce Maternal Mortality among HIV-Infected Pregnant and Postpartum Women

    PubMed Central

    Holtz, Sara A.; Thetard, Rudi; Konopka, Sarah N.; Albertini, Jennifer; Amzel, Anouk; Fogg, Karen P.

    2015-01-01

    Background: In high-prevalence populations, HIV-related maternal mortality is high with increased mortality found among HIV-infected pregnant and postpartum women compared to their uninfected peers. The scale-up of HIV-related treatment options and broader reach of programming for HIV-infected pregnant and postpartum women is likely to have decreased maternal mortality. This systematic review synthesized evidence on interventions that have directly reduced mortality among this population. Methods: Studies published between January 1, 2003 and November 30, 2014 were searched using PubMed. Of the 1,373 records screened, 19 were included in the analysis. Results: Interventions identified through the review include antiretroviral therapy (ART), micronutrients (multivitamins, vitamin A, and selenium), and antibiotics. ART during pregnancy was shown to reduce mortality. Timing of ART initiation, duration of treatment, HIV disease status, and ART discontinuation after pregnancy influence mortality reduction. Incident pregnancy in women already on ART for their health appears not to have adverse consequences for the mother. Multivitamin use was shown to reduce disease progression while other micronutrients and antibiotics had no beneficial effect on maternal mortality. Conclusions: ART was the only intervention identified that decreased death in HIV-infected pregnant and postpartum women. The findings support global trends in encouraging initiation of lifelong ART for all HIV-infected pregnant and breastfeeding women (Option B+), regardless of their CD4+ count, as an important step in ensuring appropriate care and treatment. Global Health Implications: Maternal mortality is a rare event that highlights challenges in measuring the impact of interventions on mortality. Developing effective patient-centered interventions to reduce maternal morbidity and mortality, as well as corresponding evaluation measures of their impact, requires further attention by policy makers

  5. A Systematic Review of Interventions to Reduce Maternal Mortality among HIV-Infected Pregnant and Postpartum Women

    PubMed Central

    Holtz, Sara A.; Thetard, Rudi; Konopka, Sarah N.; Albertini, Jennifer; Amzel, Anouk; Fogg, Karen P.

    2015-01-01

    Background: In high-prevalence populations, HIV-related maternal mortality is high with increased mortality found among HIV-infected pregnant and postpartum women compared to their uninfected peers. The scale-up of HIV-related treatment options and broader reach of programming for HIV-infected pregnant and postpartum women is likely to have decreased maternal mortality. This systematic review synthesized evidence on interventions that have directly reduced mortality among this population. Methods: Studies published between January 1, 2003 and November 30, 2014 were searched using PubMed. Of the 1,373 records screened, 19 were included in the analysis. Results: Interventions identified through the review include antiretroviral therapy (ART), micronutrients (multivitamins, vitamin A, and selenium), and antibiotics. ART during pregnancy was shown to reduce mortality. Timing of ART initiation, duration of treatment, HIV disease status, and ART discontinuation after pregnancy influence mortality reduction. Incident pregnancy in women already on ART for their health appears not to have adverse consequences for the mother. Multivitamin use was shown to reduce disease progression while other micronutrients and antibiotics had no beneficial effect on maternal mortality. Conclusions: ART was the only intervention identified that decreased death in HIV-infected pregnant and postpartum women. The findings support global trends in encouraging initiation of lifelong ART for all HIV-infected pregnant and breastfeeding women (Option B+), regardless of their CD4+ count, as an important step in ensuring appropriate care and treatment. Global Health Implications: Maternal mortality is a rare event that highlights challenges in measuring the impact of interventions on mortality. Developing effective patient-centered interventions to reduce maternal morbidity and mortality, as well as corresponding evaluation measures of their impact, requires further attention by policy makers

  6. Vaccination with recombinant oncosphere antigens reduces the susceptibility of sheep to infection with Taenia multiceps☆

    PubMed Central

    Gauci, Charles; Vural, Gulay; Öncel, Taraneh; Varcasia, Antonio; Damian, Veronica; Kyngdon, Craig T.; Craig, Philip S.; Anderson, Garry A.; Lightowlers, Marshall W.

    2008-01-01

    Taenia multiceps is a cestode parasite, the larval stage of which encysts in the brain of sheep, goats and cattle causing an often fatal condition. The parasite also causes zoonotic infections in humans. Homologues of the recombinant oncosphere vaccine antigens from Taenia ovis and other Taenia species were identified in T. multiceps. Sequencing of the associated T. multiceps genes and cloning of the encoding mRNA has revealed conserved features in the genes and proteins. The T. multiceps oncosphere proteins, designated Tm16 and Tm18, contain a predicted secretory signal and fibronectin type III domain. The recombinant Tm16 and Tm18 proteins were successfully expressed in Escherichia coli as fusion proteins with GST. The antigens, formulated with Quil A adjuvant, were tested in a vaccine trial in sheep. The antigens stimulated immunity in sheep against challenge infection with T. multiceps eggs. Five of nine control sheep died due to a challenge infection with T. multiceps whereas none of 20 vaccinated animals died as a result of the parasite challenge (P = 0.001). In addition, vaccination with the Tm16 protein, or Tm16 plus Tm18, induced significant protection against the number of parasites encysting in the brain as a result of the challenge infection (P = 0.023, P = 0.015, respectively). No clear relationship was apparent between the level of specific serum antibody in vaccinated animals and either the presence or absence of parasites or the number of parasites that occurred in some of the vaccinated animals. We believe this study is the first description of recombinant vaccine-related investigations for T. multiceps. The recombinant oncosphere antigens identified may allow development of effective vaccination strategies against T. multiceps infection in sheep. They raise the potential for the development of a combined vaccine with the Echinococcus granulosus EG95 antigen for prevention of T. multiceps as well as preventing the transmission of cystic

  7. Vaccination of pigs reduces Torque teno sus virus viremia during natural infection.

    PubMed

    Jiménez-Melsió, Alexandra; Rodriguez, Fernando; Darji, Ayub; Segalés, Joaquim; Cornelissen-Keijsers, Vivian; van den Born, Erwin; Kekarainen, Tuija

    2015-07-01

    Anelloviruses are a group of single-stranded circular DNA viruses infecting several vertebrate species. Four species have been found to infect swine, namely Torque teno sus virus (TTSuV) 1a and 1b (TTSuV1a, TTSuV1b; genus Iotatorquevirus), TTSuVk2a and TTSuVk2b (genus Kappatorquevirus). TTSuV infection in pigs is distributed worldwide, and is characterized by a persistent viremia. However, the real impact, if any, on the pig health is still under debate. In the present study, the impact of pig immunization on TTSuVk2a loads was evaluated. For this, three-week old conventional pigs were primed with DNA vaccines encoding the ORF2 gene and the ORF1-A, ORF1-B, and ORF1-C splicing variants and boosted with purified ORF1-A and ORF2 Escherichia coli proteins, while another group served as unvaccinated control animals, and the viral load dynamics during natural infection was observed. Immunization led to delayed onset of TTSuVk2a infection and at the end of the study when the animals were 15 weeks of age, a number of animals in the immunized group had cleared the TTSuVk2a viremia, which was not the case in the control group. This study demonstrated for the first time that TTSuV viremia can be controlled by a combined DNA and protein immunization, especially apparent two weeks after the first DNA immunization before seroconversion was observed. Further studies are needed to understand the mechanisms behind this and its impact for pig producers.

  8. Nanoencapsulated curcumin and praziquantel treatment reduces periductal fibrosis and attenuates bile canalicular abnormalities in Opisthorchis viverrini-infected hamsters.

    PubMed

    Charoensuk, Lakhanawan; Pinlaor, Porntip; Wanichwecharungruang, Supason; Intuyod, Kitti; Vaeteewoottacharn, Kulthida; Chaidee, Apisit; Yongvanit, Puangrat; Pairojkul, Chawalit; Suwannateep, Natthakitta; Pinlaor, Somchai

    2016-01-01

    This study investigated the effects of nanoencapsulated curcumin (NEC) and praziquantel (PZQ) treatment on the resolution of periductal fibrosis (PDF) and bile canalicular (BC) abnormalities in Opisthorchis viverrini infected hamsters. Chronic O. viverrini infection (OV) was initially treated with either PZQ (OP) and subsequently treated with NEC (OP+NEC), curcumin (OP+Cur) or unloaded carriers (OP+carrier) daily for one month. OP+NEC treatment reduced the PDF by suppression of fibrotic markers (hydroxyproline content, α-SMA, CTGF, fibronectin, collagen I and III), cytokines (TGF-β and TNF-α) and TIMP-1, 2, 3 expression and upregulation of MMP-7, 13 genes. Higher activity of NEC in reducing fibrosis compared to curcumin was also demonstrated in in vitro studies. Moreover, OP+NEC also prevented BC abnormalities and upregulated several genes involved in bile acid metabolism. These results demonstrate that NEC and PZQ treatment reduces PDF and attenuates BC defect in experimental opisthorchiasis. From the Clinical Editor: Infection by Opisthorchis viverrini leads to liver fibrosis and affects population in SE Asia. Currently, praziquantel (PZQ) is the drug of choice but this drug has significant side effects. In this study, the authors combined curcumin (NEC) and praziquantel in a nanocarrier to test the anti-oxidative effect of curcumin in an animal model. The encouraging results may pave a way for better treatment in the future.

  9. Curcumin reduces oxidative and nitrative DNA damage through balancing of oxidant-antioxidant status in hamsters infected with Opisthorchis viverrini.

    PubMed

    Pinlaor, Somchai; Yongvanit, Puangrat; Prakobwong, Suksanti; Kaewsamut, Butsara; Khoontawad, Jarinya; Pinlaor, Porntip; Hiraku, Yusuke

    2009-10-01

    Opisthorchis viverrini (OV) infection is endemic in northeastern Thailand. We have previously reported that OV infection induces oxidative and nitrative DNA damage via chronic inflammation, which contributes to the disease and cholangiocarcinogenesis. Here, we examined the effect of curcumin, an antioxidant, on pathogenesis in OV-infected hamsters. DNA lesions were detected by double immunofluorescence and the hepatic expression of oxidant-generating and antioxidant genes was assessed by quantitative RT-PCR analysis. Dietary 1.0% curcumin significantly decreased OV-induced accumulation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an oxidative DNA lesion, and 8-nitroguanine, a nitrative DNA lesion, in the nucleus of bile duct epithelial and inflammatory cells. Expression of oxidant-generating genes (inducible nitric oxide synthase; iNOS, its nuclear transcriptional factor, NF-kappaB, and cyclooxygenase-2), and plasma levels of nitrate, malondialdehyde, and alanine aminotransferase, were also decreased in curcumin-treated group. In contrast, curcumin increased the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase and catalase), and ferric-reducing anti-oxidant power in the plasma. In conclusion, curcumin reduced oxidative and nitrative DNA damage by suppression of oxidant-generating genes and enhancement of antioxidant genes, leading to inhibition of oxidative and nitrative stress. Therefore, curcumin may be used as a chemopreventive agent to reduce the severity of OV-associated diseases and the risk of cholangiocarcinoma (CCA).

  10. Dietary sulforaphane-rich broccoli sprouts reduce colonization and attenuate gastritis in Helicobacter pylori-infected mice and humans.

    PubMed

    Yanaka, Akinori; Fahey, Jed W; Fukumoto, Atsushi; Nakayama, Mari; Inoue, Souta; Zhang, Songhua; Tauchi, Masafumi; Suzuki, Hideo; Hyodo, Ichinosuke; Yamamoto, Masayuki

    2009-04-01

    The isothiocyanate sulforaphane [SF; 1-isothiocyanato-4(R)-methylsulfinylbutane] is abundant in broccoli sprouts in the form of its glucosinolate precursor (glucoraphanin). SF is powerfully bactericidal against Helicobacter pylori infections, which are strongly associated with the worldwide pandemic of gastric cancer. Oral treatment with SF-rich broccoli sprouts of C57BL/6 female mice infected with H. pylori Sydney strain 1 and maintained on a high-salt (7.5% NaCl) diet reduced gastric bacterial colonization, attenuated mucosal expression of tumor necrosis factor-alpha and interleukin-1beta, mitigated corpus inflammation, and prevented expression of high salt-induced gastric corpus atrophy. This therapeutic effect was not observed in mice in which the nrf2 gene was deleted, strongly implicating the important role of Nrf2-dependent antioxidant and anti-inflammatory proteins in SF-dependent protection. Forty-eight H. pylori-infected patients were randomly assigned to feeding of broccoli sprouts (70 g/d; containing 420 micromol of SF precursor) for 8 weeks or to consumption of an equal weight of alfalfa sprouts (not containing SF) as placebo. Intervention with broccoli sprouts, but not with placebo, decreased the levels of urease measured by the urea breath test and H. pylori stool antigen (both biomarkers of H. pylori colonization) and serum pepsinogens I and II (biomarkers of gastric inflammation). Values recovered to their original levels 2 months after treatment was discontinued. Daily intake of sulforaphane-rich broccoli sprouts for 2 months reduces H. pylori colonization in mice and improves the sequelae of infection in infected mice and in humans. This treatment seems to enhance chemoprotection of the gastric mucosa against H. pylori-induced oxidative stress.

  11. Arginine decarboxylase inhibitors reduce the capacity of Trypanosoma cruzi to infect and multiply in mammalian host cells.

    PubMed Central

    Kierszenbaum, F; Wirth, J J; McCann, P P; Sjoerdsma, A

    1987-01-01

    The capacity of blood (trypomastigote) forms of Trypanosoma cruzi to infect mouse peritoneal macrophages or rat heart myoblasts in vitro was inhibited by treatment of the trypomastigotes with DL-alpha-difluoromethylarginine (F2Me Arg), monofluoromethylagmatine, or (E)-alpha-monofluoromethyl-3-4-dehydroarginine--all irreversible inhibitors of arginine decarboxylase. Similar results were obtained when F2MeArg-treated parasites were incubated with rat heart myoblasts. The inhibitory effects were characterized by marked reductions in both the proportion of infected cells and the number of parasites per 100 host cells. The concentrations of the arginine decarboxylase inhibitors that affected infectivity had no detectable effect on either the concentration or motility of the parasite and, therefore, could not have affected the collision frequency. F2MeArg appeared to inhibit the ability of T. cruzi to penetrate the host cells since the drug had no significant effect on the extent of parasite binding to the surface of the host cells. The inhibitory effect of F2MeArg was markedly reduced or abrogated in the presence of either agmatine or putrescine, as would have been expected if F2MeArg acted by inhibiting arginine decarboxylase. Addition of F2MeArg to macrophage or myoblast cultures immediately after infection or at a time when virtually all of the intracellular parasites had transformed into the multiplicative amastigote form, resulted in a markedly reduced parasite growth rate. This effect was also prevented by exogenous agmatine. These results indicate the importance of polyamines and polyamine biosynthesis in the following two important functions of T. cruzi: invasion of host cells and intracellular multiplication. Furthermore, concentrations of the inhibitors tested that affected the parasite did not alter the viability of the host cells, the cellular density of the cultures, or the ability of uninfected myoblasts to grow. Thus, arginine decarboxylase inhibitors may

  12. Effects of reduced mucus oxygen concentration in airway Pseudomonas infections of cystic fibrosis patients

    PubMed Central

    Worlitzsch, Dieter; Tarran, Robert; Ulrich, Martina; Schwab, Ute; Cekici, Aynur; Meyer, Keith C.; Birrer, Peter; Bellon, Gabriel; Berger, Jürgen; Weiss, Tilo; Botzenhart, Konrad; Yankaskas, James R.; Randell, Scott; Boucher, Richard C.; Döring, Gerd

    2002-01-01

    Current theories of CF pathogenesis predict different predisposing “local environmental” conditions and sites of bacterial infection within CF airways. Here we show that, in CF patients with established lung disease, Psuedomonas aeruginosa was located within hypoxic mucopurulent masses in airway lumens. In vitro studies revealed that CF-specific increases in epithelial O2 consumption, linked to increased airway surface liquid (ASL) volume absorption and mucus stasis, generated steep hypoxic gradients within thickened mucus on CF epithelial surfaces prior to infection. Motile P. aeruginosa deposited on CF airway surfaces penetrated into hypoxic mucus zones and responded to this environment with increased alginate production. With P. aeruginosa growth in oxygen restricted environments, local hypoxia was exacerbated and frank anaerobiosis, as detected in vivo, resulted. These studies indicate that novel therapies for CF include removal of hypoxic mucus plaques and antibiotics effective against P. aeruginosa adapted to anaerobic environments. PMID:11827991

  13. The augmented neutrophil respiratory burst in response to Escherichia coli is reduced in liver cirrhosis during infection.

    PubMed

    Bruns, T; Peter, J; Hagel, S; Herrmann, A; Stallmach, A

    2011-06-01

    Several functional abnormalities in phagocytes from patients with liver cirrhosis contribute to an increased risk of infection. An increased resting respiratory burst has been observed in neutrophils from cirrhotic patients. We investigated whether an infection in cirrhosis affects the respiratory burst capacity of neutrophils and monocytes in response to Escherichia coli. This study included 45 hospitalized patients with liver cirrhosis and clinical signs of infection, 39 patients with liver cirrhosis in the absence of infection and 29 healthy subjects. Respiratory burst, lipopolysaccharide-binding protein (LBP), and immunoglobulin (Ig)G-autoantibodies against oxidized low-density lipoproteins (ab-oxLDL) were measured. The fraction of neutrophils spontaneously producing reactive oxygen species (ROS) was elevated in liver cirrhosis (P < 0·01). The neutrophil resting burst increased with Child-Pugh stage (P = 0·02) and correlated with augmented ROS release in response to opsonized E. coli (P < 0·05). Although LBP was increased in patients with cirrhosis (P < 0·01), higher LBP levels correlated with a lower resting burst in neutrophils (r(s)  = -0·395; P < 0·01). In the presence of infection, the resting burst was unaltered. However, neutrophil ROS release in response to E. coli was reduced markedly (P = 0·01), and it decreased as serum C-reactive protein (CRP) concentration rose (r(s)  = -0·437; P < 0·01), indicating the development of a sepsis-like immune paralysis. A positive correlation between ab-oxLDL and ROS release was observed (P < 0·01). In conclusion, the respiratory burst increases with severity of liver cirrhosis but is restrained by increasing LBP levels. Augmented ROS release in response to E. coli is accompanied by elevated markers of oxidative damage and becomes exhausted in the presence of infection.

  14. Mayo Clinic Reduces Catheter-Associated Urinary Tract Infections Through a Bundled 6-C Approach.

    PubMed

    Sampathkumar, Priya; Barth, Jean Wentink; Johnson, Maureen; Marosek, Nick; Johnson, Maren; Worden, Wendy; Lembke, Jill; Twing, Heather; Buechler, Tamara; Dhanorker, Sarah; Keigley, Danielle; Thompson, Rodney

    2016-06-01

    The primary CAUTI reduction strategies of ensuring aseptic technique during catheter placement and reducing urinary catheter utilization were already in place at our institution. A multidisciplinary team approach, which entailed the use of QI methodology and engagement of frontline staff, resulted in the identification of additional strategies to reduce CAUTI. By implementing these strategies, we successfully reduced CAUTIs and have sustained this reduction through March 2016. The tools created during this project can be easily adapted for use at other institutions. PMID:27344686

  15. Telmisartan to Reduce Cardiovascular Risk in Older HIV-Infected Adults: A Pilot Study

    PubMed Central

    2015-01-01

    Background HIV-infected persons are at increased cardiovascular disease (CVD) risk, but traditional CVD therapies are understudied in this population. Telmisartan is an angiotensin receptor blocker and PPAR-γ agonist that improves endothelial function and cardiovascular mortality in HIV-uninfected populations. We assessed the effects of telmisartan on endothelial function in older HIV-infected persons at risk for CVD in a small pilot study. Methods HIV-infected individuals ≥50 years old on suppressive antiretroviral therapy (ART) with ≥1 traditional CVD risk factor received open label telmisartan 80 mg daily for six weeks. Brachial artery flow-mediated dilation (FMD) measured endothelial function. The primary endpoint was six-week change in maximum relative FMD. Results Seventeen participants enrolled; 16 completed all evaluations (88% men, 65% non-White, median age 60 years, CD4+ T lymphocyte count 625 cells/mm3). ART included 71% PI, 29% NNRTI, 29% integrase inhibitor, 65% tenofovir and 29% abacavir. CVD risk factor prevalence included 76% hyperlipidemia, 65% hypertension, 18% smoking and 12% diabetes mellitus. After six weeks, statistically significant blood pressure changes were observed (systolic −16.0 mmHg, diastolic −6.0 mmHg) without significant changes in FMD. In subset analyses, FMD increased more among abacavir-treated, PI-treated and non-smoking participants. Conclusions No significant FMD changes were observed after six weeks of telmisartan therapy; however, abacavir- and PI-treated participants and non-smokers showed greater FMD increases. Additional studies are needed to explore the effects of telmisartan on endothelial function among HIV-infected individuals with traditional CVD and/or ART-specific risk factors. PMID:26360501

  16. Mediastinal transposition of the omentum reduces infection severity and pharmacy cost for patients undergoing esophagectomy

    PubMed Central

    Ye, Peng; Cao, Jin-Lin; Li, Qiu-Yuan; Wang, Zhi-Tian; Yang, Yun-Hai; Lv, Wang

    2016-01-01

    Background The greater omentum has been found to be immunologically competent in protecting abdominal organs from inflammation. Anastomotic omentoplasty has been used and proven effective in preventing anastomotic leaks after an esophagectomy. However, pulmonary complications are still a substantial problem after an esophagectomy. This study investigated the benefits of mediastinal transposition of the omentum, a modification of the conventional omental wrapping technique, in controlling overall postoperative intrathoracic complications. Methods From January 2010 to March 2015, 208 consecutive patients receiving an open Ivor-Lewis esophagectomy at our institution were retrospectively reviewed. One hundred twenty-one patients with omentum mediastinal transposition were assigned to the transposition group and 87 patients without omental transposition were placed in the non-transposition group. The patients’ demographics, postoperative short-term outcomes, and in-hospital cost were documented and analyzed. Results Mediastinal transposition of the omentum led to a shorter postoperative hospital stay (14 vs. 16 d, P=0.038) and a lower intrathoracic infection rate (30.6% vs. 48.3%, P=0.009). Intrathoracic infection was milder in the transposition group (P=0.005), though a non-significant was found in overall complications (P=0.071). The multivariate logistic regression analyses identified omentum mediastinal transposition (P=0.007, OR=0.415) as an independent protective factor for postoperative intrathoracic infection. The total in-hospital cost was comparable in both groups (P>0.05), whereas the pharmacy cost was lower in the transposition group than in the non-transposition group (¥21,668 vs. ¥27,012, P=0.010). Conclusions Mediastinal transposition of the omentum decreases the rate and severity of postoperative intrathoracic infection following an open Ivor-Lewis esophagectomy. This result in decreased pharmacy costs, rather than resulting in an increased economic

  17. Reduced thrombin generation increases host susceptibility to group A streptococcal infection

    PubMed Central

    Sun, Hongmin; Wang, Xixi; Degen, Jay L.

    2009-01-01

    Bacterial plasminogen activators are commonplace among microbial pathogens, implying a central role of host plasmin in supporting bacterial virulence. Group A streptococci (GAS) secrete streptokinase, a specific activator of human plasminogen (PLG). The critical contribution of the streptokinase-PLG interaction to GAS pathogenicity was recently demonstrated using mice expressing human PLG. To examine the importance of thrombin generation in antimicrobial host defense, we challenged mice with deficiency of factor V (FV) in either the plasma or platelet compartment. Reduction of FV in either pool resulted in markedly increased mortality after GAS infection, with comparison to heterozygous F5-deficient mice suggesting a previously unappreciated role for the platelet FV pool in host defense. Mice with complete deficiency of fibrinogen also demonstrated markedly increased mortality to GAS infection relative to controls. Although FV Leiden may be protective in the setting of severe sepsis in humans, no significant survival advantage was observed in GAS-infected mice carrying the FV Leiden mutation. Taken together, our data support the hypothesis that local thrombosis/fibrin deposition limits the survival and dissemination of at least a subset of microbial pathogens and suggest that common variation in hemostatic factors among humans could affect host susceptibility to a variety of infectious diseases. PMID:19056689

  18. Closed Catheter Access System Implementation in Reducing the Bloodstream Infection Rate in Low Birth Weight Preterm Infants

    PubMed Central

    Rundjan, Lily; Rohsiswatmo, Rinawati; Paramita, Tiara Nien; Oeswadi, Chrissela Anindita

    2015-01-01

    Background: Bloodstream infection (BSI) is one of the significant causes of morbidity and mortality encountered in a neonatal intensive care unit, especially in developing countries. Despite the implementation of infection control practices, such as strict hand hygiene, the BSI rate in our hospital is still high. The use of a closed catheter access system to reduce BSI related to intravascular catheter has hitherto never been evaluated in our hospital. Objective: To determine the effects of closed catheter access system implementation in reducing the BSI rate in preterm neonates with low birth weight. Methods: Randomized clinical trial was conducted on 60 low birth weight preterm infants hospitalized in the neonatal unit at Cipto Mangunkusumo Hospital, Jakarta, Indonesia from June to September 2013. Randomized subjects either received a closed or non-closed catheter access system. Subjects were monitored for 2 weeks for the development of BSI based on clinical signs, abnormal infection parameters, and blood culture. Results: Closed catheter access system implementation gave a protective effect toward the occurrence of culture-proven BSI (relative risk 0.095, 95% CI 0.011–0.85, p = 0.026). Risk of culture-proven BSI in the control group was 10.545 (95% CI 1.227–90.662, p = 0.026). BSI occurred in 75% of neonates without risk factors of infection in the control group compared to none in the study group. Conclusion: The use of a closed catheter access system reduced the BSI in low birth weight preterm infants. Choosing the right device design, proper disinfection of device, and appropriate frequency of connector change should be done simultaneously. PMID:25853110

  19. Enzymatic treatment of duck hepatitis B virus: Topology of the surface proteins for virions and noninfectious subviral particles

    SciTech Connect

    Franke, Claudia; Matschl, Urte; Bruns, Michael . E-mail: mbruns@hpi.uni-hamburg.de

    2007-03-01

    The large surface antigen L of duck hepatitis B virus exhibits a mixed topology with the preS domains of the protein alternatively exposed to the particles' interior or exterior. After separating virions from subviral particles (SVPs), we compared their L topologies and showed that both particle types exhibit the same amount of L with the following differences: 1-preS of intact virions was enzymatically digested with chymotrypsin, whereas in SVPs only half of preS was accessible, 2-phosphorylation of L at S118 was completely removed by phosphatase treatment only in virions, 3-iodine-125 labeling disclosed a higher ratio of exposed preS to S domains in virions compared to SVPs. These data point towards different surface architectures of virions and SVPs. Because the preS domain acts in binding to a cellular receptor of hepatocytes, our findings implicate the exclusion of SVPs as competitors for the receptor binding and entry of virions.

  20. Preventing Cleavage of the Respiratory Syncytial Virus Attachment Protein in Vero Cells Rescues the Infectivity of Progeny Virus for Primary Human Airway Cultures

    PubMed Central

    Corry, Jacqueline; Johnson, Sara M.; Cornwell, Jessica

    2015-01-01

    ABSTRACT All live attenuated respiratory syncytial virus (RSV) vaccines that have advanced to clinical trials have been produced in Vero cells. The attachment (G) glycoprotein in virions produced in these cells is smaller than that produced in other immortalized cells due to cleavage. These virions are 5-fold less infectious for primary well-differentiated human airway epithelial (HAE) cell cultures. Because HAE cells are isolated directly from human airways, Vero cell-grown vaccine virus would very likely be similarly inefficient at initiating infection of the nasal epithelium following vaccination, and therefore, a larger inoculum would be required for effective vaccination. We hypothesized that Vero cell-derived virus containing an intact G protein would be more infectious for HAE cell cultures. Using protease inhibitors with increasing specificity, we identified cathepsin L to be the protease responsible for cleavage. Our evidence suggests that cleavage occurs in the late endosome or lysosome during endocytic recycling. Cathepsin L activity was 100-fold greater in Vero cells than in HeLa cells. In addition, cathepsin L was able to cleave the G protein in Vero cell-grown virions but not in HeLa cell-grown virions, suggesting a difference in G-protein posttranslational modification in the two cell lines. We identified by mutagenesis amino acids important for cleavage, and these amino acids included a likely cathepsin L cleavage site. Virus containing a modified, noncleavable G protein produced in Vero cells was 5-fold more infectious for HAE cells in culture, confirming our hypothesis and indicating the value of including such a mutation in future live attenuated RSV vaccines. IMPORTANCE Worldwide, RSV is the second leading infectious cause of infant death, but no vaccine is available. Experimental live attenuated RSV vaccines are grown in Vero cells, but during production the virion attachment (G) glycoprotein is cleaved. Virions containing a cleaved G protein

  1. Role of a reducing environment in disassembly of the herpesvirus tegument

    SciTech Connect

    Newcomb, William W.; Jones, Lisa M.; Dee, Alexander; Chaudhry, Farid; Brown, Jay C.

    2012-09-15

    Initiation of infection by herpes family viruses involves a step in which most of the virus tegument becomes detached from the capsid. Detachment takes place in the host cell cytosol near the virus entry site and it is followed by dispersal of tegument proteins and disappearance of the tegument as a distinct entity. Here we describe the results of experiments designed to test the idea that the reducing environment of the cytosol may contribute to tegument detachment and disassembly. Non-ionic detergent was used to remove the membrane of purified herpes simplex virus under control and reducing conditions. The effects on the tegument were then examined by SDS-PAGE and electron microscopy. Protein analysis demonstrated that most major tegument proteins were removed under both oxidizing and reducing conditions except for UL49 which required a reducing environment. It is proposed therefore that the reducing conditions in the cytosol are involved in removal of UL49 protein. Electron microscopic analysis revealed that capsids produced under oxidizing conditions contained a coating of protein that was absent in reduced virions and which correlated uniquely with the presence of UL49. This capsid-associated layer is suggested to be the location of UL49 in the extracted virion.

  2. Sodium hypochlorite: A promising agent for reducing Botrytis cinerea infection on rose flowers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Botrytis cinerea is a fungal pathogen that greatly reduces the postharvest quality of rose flowers. We determined the potential of sodium hypochlorite (NaOCl), an oxidizer with antimicrobial activity, to reduce the incidence of disease on flowers. A postharvest dip in 200 µL L-1 NaOCl for 10 s at ...

  3. Protective antibody therapy is associated with reduced chemokine transcripts in herpes simplex virus type 1 corneal infection.

    PubMed Central

    Su, Y H; Yan, X T; Oakes, J E; Lausch, R N

    1996-01-01

    Herpes simplex virus type 1 (HSV-1) infection on the murine cornea induces an intense inflammatory response which can lead to blindness. This disease, known as herpes stromal keratitis, can be prevented by the timely passive transfer of monoclonal antibody specific for viral glycoprotein D (gD). Precisely how antibody treatment prevents excessive corneal inflammation is not known. In this study we investigated whether chemokine mRNA expression is inhibited by antibody treatment. Total cellular RNAs isolated from normal corneas and at various times after virus infection were analyzed via reverse transcription-PCR for mRNA coding for seven different chemokines. Constitutive levels of IP-10, KC, MIP-2, MCP-1, MIP-1 beta, and RANTES mRNA were detected in uninfected corneas of BALB/c mice. When the cornea was mechanically traumatized, message for all six chemokines was transiently elevated above constitutive levels. In contrast, HSV-1 infection resulted in prolonged enhanced chemokine message expression. The kinetics of mRNA accumulation was distinctive for each chemokine analyzed. MIP-1 alpha message, not detected constitutively, was not evident until day 7 postinfection. Administration of anti-HSV gD monoclonal antibody 1 day after infection was associated with reduced message for MIP-2, MCP-1, MIP-1 alpha, and MIP-1 beta. IP-10, KC, and RANTES messages were not altered. Collectively, our results suggest that anti-gD treatment may protect, at least in part, by inhibiting production of chemokines believed to promote inflammation. PMID:8551595

  4. Influenza virus-specific RNA and protein syntheses in cells infected with temperature-sensitive mutants defective in the genome segment encoding nonstructural proteins.

    PubMed

    Wolstenholme, A J; Barrett, T; Nichol, S T; Mahy, B W

    1980-07-01

    Virus-specific protein and RNA syntheses have been analyzed in chicken embryo fibroblast cells infected with two group IV temperature-sensitive (ts) mutants of influenza A (fowl plague) virus in which the ts lesion maps in RNA segment 8 (J. W. Almond, D. McGeoch, and R. D. Barry, Virology 92:416-427, 1979), known to code to code for two nonstructural proteins, NS1 and NS2. Both mutants induced the synthesis of similar amounts of all the early virus-specific proteins (P1, P2, P3, NP, and NS1) at temperatures that were either permissive (34 degrees C) or nonpermissive (40.5 degrees C) for replication. However, the synthesis of M protein, which normally accumulates late in infection, was greatly reduced in ts mutant-infected cells at 40.5 degrees C compared to 34 degrees C. The NS2 protein was not detected at either temperature in cells infected with one mutant (mN3), and was detected only at the permissive temperature in cells infected with mutant ts47. There was no overall reduction in polyadenylated (A+) complementary RNA, which functions as mRNA, in cells infected with these mutants at 40.5 degrees C compared to 34 degrees C, nor was there any evidence of selective accumulation of this type of RNA within the nucleus at the nonpermissive temperature. No significant differences in ts mutant virion RNA transcriptase activity were detected by assays in vitro at 31 and 40.5 degrees C compared to wild-type virus. Virus-specific non-polyadenylated (A-) complementary RNA, which is believed to act as the template for new virion RNA production, accumulated normally in cells at both 34 and 40.5 degrees C, but at 40.5 degrees C accumulation of new virion RNA was reduced by greater than 90% when compared to accumulation at 34 degrees C.

  5. Antibody and CD8+ T cell memory response to influenza A/PR/8/34 infection is reduced in treadmill-exercised mice, yet still protective.

    PubMed

    Warren, Kristi; Thompson, Nicholas; Wannemuehler, Michael; Kohut, Marian

    2013-05-15

    Moderate exercise may decrease the severity of influenza infection and reduce lung viral load. The possibility that an exercise-associated reduction in lung viral load early in infection could contribute to decreased serum antibody and reduced memory response were investigated. BALB/c mice exercised for 8 wk and were then infected with influenza A/PR/8/34 (intranasal route). Influenza-specific serum antibody was assessed for 6 mo post primary infection, at which time mice were infected again with influenza A/PR/8/34. After primary infection, exercise reduced morbidity/mortality, attenuated lung cytokines, and decreased serum anti-influenza IgG and IgG2a from day 14 to day 180 post primary infection. After secondary infectious challenge, exercised mice did not show any signs of illness, but had reduced serum anti-influenza IgG and IgG2a, increased IgG1, and reduced influenza-specific recruited and resident CD8+ granzyme B+ T cells within the lungs. When influenza virus was administered by an intraperitoneal route during primary infection, exercise did not alter serum anti-influenza IgG, IgG1, or IgG2a, suggesting the exercise effect was specific to the lung environment. Exercise-induced enhancement of respiratory host defense to primary influenza infection results in decreased serum antibody and lung CD8+ T cell memory response, but does not compromise resistance to secondary infectious challenge.

  6. Analysis of ABCA1 and Cholesterol Efflux in HIV-Infected Cells.

    PubMed

    Mukhamedova, Nigora; Brichacek, Beda; Darwish, Christina; Popratiloff, Anastas; Sviridov, Dmitri; Bukrinsky, Michael

    2016-01-01

    Cholesterol is an essential component of the cellular membranes and, by extension, of the HIV envelope membrane, which is derived from the host cell plasma membrane. Depletion of the cellular cholesterol has an inhibitory effect on HIV assembly, reduces infectivity of the produced virions, and makes the cell less susceptible to HIV infection. It is not surprising that the virus has evolved to gain access to cellular proteins regulating cholesterol metabolism. One of the key mechanisms used by HIV to maintain high levels of cholesterol in infected cells is Nef-mediated inhibition of cholesterol efflux and the cholesterol transporter responsible for this process, ABCA1. In this chapter, we describe methods to investigate these effects of HIV-1 infection.

  7. Multidisciplinary Oncoplastic Approach Reduces Infection in Chest Wall Resection and Reconstruction for Malignant Chest Wall Tumors

    PubMed Central

    Malahias, Marco N.; Balasubramanian, Balapathiran; Djearaman, Madava G.; Naidu, Babu; Grainger, Melvin F.; Kalkat, Maninder

    2016-01-01

    Background: Management of complex thoracic defects post tumor extipiration is challenging because of the nature of pathology, the radical approach, and the insertion of prosthetic material required for biomechanical stability. Wound complications pose a significant problem that can have detrimental effect on patient outcome. The authors outline an institutional experience of a multidisciplinary thoracic oncoplastic approach to improve outcomes. Methods: Prospectively collected data from 71 consecutive patients treated with chest wall resection and reconstruction were analyzed (2009–2015). The demographic data, comorbidities, operative details, and outcomes with special focus on wound infection were recorded. All patients were managed in a multidisciplinary approach to optimize perioperative surgical planning. Results: Pathology included sarcoma (78%), locally advanced breast cancer (15%), and desmoids (6%), with age ranging from 17 to 82 years (median, 42 years) and preponderance of female patients (n = 44). Chest wall defects were located anterior and anterolateral (77.5%), posterior (8.4%), and apical axillary (10%) with skeletal defect size ranging from 56 to 600 cm2 (mean, 154 cm2). Bony reconstruction was performed using polyprolene mesh, methyl methacrylate prosthesis, and titanium plates. Soft tissue reconstructions depended on size, location, and flap availability and were achieved using regional, distant, and free tissue flaps. The postoperative follow-up ranged from 5 to 70 months (median, 32 months). All flaps survived with good functional and aesthetic outcome, whereas 2 patients experienced surgical site infection (2.8%). Conclusions: Multidisciplinary thoracic oncoplastic maximizes outcome for patients with large resection of chest wall tumors with reduction in surgical site infection and wound complications particularly in association with rigid skeletal chest wall reconstruction. PMID:27536488

  8. Prophylaxis with teicoplanin and cefuroxime reduces the rate of prosthetic joint infection after primary arthroplasty.

    PubMed

    Tornero, Eduard; García-Ramiro, Sebastian; Martínez-Pastor, Juan C; Bori, Guillem; Bosch, Jordi; Morata, Laura; Sala, Marta; Basora, Misericordia; Mensa, Josep; Soriano, Alex

    2015-02-01

    The aim of this study was to compare the prosthetic joint infection (PJI) rate after total joint arthroplasty in two consecutive periods of treatment with different antibiotic prophylaxes: cefuroxime versus cefuroxime plus teicoplanin. We retrospectively reviewed 1,896 patients who underwent total hip arthroplasty or total knee arthroplasty between March 2010 and February 2013. From March 2010 to August 2011, patients received 1.5 g of cefuroxime during induction of anesthesia and another 1.5 g 2 h later (the C group). From September 2011, 800 mg of teicoplanin was added to cefuroxime (the CT group). Throughout the period studied, there were no variations in pre- or postoperative protocols. Univariate and multivariate analyses were performed to evaluate independent predictors of PJI. There were 995 (55.7%) patients in the C group and 791 (44.3%) in the CT group. Patients in the CT group had a significantly lower PJI rate than patients in the C group (1.26% versus 3.51%, P=0.002). There were no infections due to Staphylococcus aureus in the CT group (0% versus 1.6% in the C group, P<0.001). A stepwise forward Cox regression model identified male sex (hazard ratio [HR], 3.85; 95% confidence interval [CI], 2.09 to 7.18), a body mass index of ≥35 kg/m2 (HR, 2.93; 95% CI, 1.37 to 6.27), the presence of lung disease (HR, 2.46; 95% CI, 1.17 to 5.15), and red blood cell transfusion (HR, 3.70; 95% CI, 1.89 to 7.23) to be independent variables associated with a higher risk of PJI. The addition of teicoplanin was associated with a lower risk of infection (HR, 0.35; 95% CI, 0.17 to 0.74). In conclusion, the addition of teicoplanin to cefuroxime during primary arthroplasty was associated with a significant reduction in the global PJI rate due to a reduction of infections caused by Gram-positive bacteria.

  9. RAB1A promotes Vaccinia virus replication by facilitating the production of intracellular enveloped virions

    SciTech Connect

    Pechenick Jowers, Tali; Featherstone, Rebecca J.; Reynolds, Danielle K.; Brown, Helen K.; James, John; Prescott, Alan; Haga, Ismar R.; Beard, Philippa M.

    2015-01-15

    Vaccinia virus (VACV) is a large double-stranded DNA virus with a complex cytoplasmic replication cycle that exploits numerous cellular proteins. This work characterises the role of a proviral cellular protein, the small GTPase RAB1A, in VACV replication. Using siRNA, we identified RAB1A as required for the production of extracellular enveloped virions (EEVs), but not intracellular mature virions (IMVs). Immunofluorescence and electron microscopy further refined the role of RAB1A as facilitating the wrapping of IMVs to become intracellular enveloped virions (IEVs). This is consistent with the known function of RAB1A in maintenance of ER to Golgi transport. VACV can therefore be added to the growing list of viruses which require RAB1A for optimal replication, highlighting this protein as a broadly proviral host factor. - Highlights: • Characterisation of the role of the small GTPase RAB1A in VACV replication. • RAB1A is not required for production of the primary virion form (IMV). • RAB1A is required for production of processed virion forms (IEVs, CEVs and EEVs). • Consistent with known role of RAB1A in ER to Golgi transport.

  10. The Recombinant Maize Ribosome-Inactivating Protein Transiently Reduces Viral Load in SHIV89.6 Infected Chinese Rhesus Macaques

    PubMed Central

    Wang, Rui-Rui; Au, Ka-Yee; Zheng, Hong-Yi; Gao, Liang-Min; Zhang, Xuan; Luo, Rong-Hua; Law, Sue Ka-Yee; Mak, Amanda Nga-Sze; Wong, Kam-Bo; Zhang, Ming-Xu; Pang, Wei; Zhang, Gao-Hong; Shaw, Pang-Chui; Zheng, Yong-Tang

    2015-01-01

    Ribosome inactivating proteins (RIPs) inhibit protein synthesis by depurinating the large ribosomal RNA and some are found to possess anti-human immunodeficiency virus (HIV) activity. Maize ribosome inactivating protein (RIP) has an internal inactivation loop which is proteolytically removed for full catalytic activity. Here, we showed that the recombinant active maize RIP protected chimeric simian-human immunodeficiency virus (SHIV) 89.6-infected macaque peripheral blood mononuclear cells from lysis ex vivo and transiently reduced plasma viral load in SHIV89.6-infected rhesus macaque model. No evidence of immune dysregulation and other obvious side-effects was found in the treated macaques. Our work demonstrates the potential development of maize RIP as an anti-HIV agent without impeding systemic immune functions. PMID:25606813

  11. Quinolizidine alkaloids reduced mortality in EV71-infected mice by compensating for the levels of T cells.

    PubMed

    Yang, Yajun; Guan, Feifei; Bai, Lin; Zhang, Li; Liu, Jiangning; Pan, Xiandao; Zhang, Lianfeng

    2015-09-01

    Recent outbreak of hand, foot and mouse disease caused by enterovirus 71 is a serious threat to infants and children in Asia-Pacific countries. No vaccines or antiviral therapies are available against this infection. In this study, we found that quinolizidine alkaloids could improve the levels of T cells in mice. The structure-activity relationships demonstrated that the oxidation and double bonds are important for the excellent potency. Oxysophocarpine, the most effective compound of six quinolizidine alkaloids, could also relieve symptoms and reduce mortality in lethal enterovirus 71-infected mice through compensating for the decreased levels of T cells. This work suggested that quinolizidine alkaloids have the potential against enterovirus 71 for further development of novel antiviral drugs.

  12. A lean Six Sigma team increases hand hygiene compliance and reduces hospital-acquired MRSA infections by 51%.

    PubMed

    Carboneau, Clark; Benge, Eddie; Jaco, Mary T; Robinson, Mary

    2010-01-01

    A low hand hygiene compliance rate by healthcare workers increases hospital-acquired infections to patients. At Presbyterian Healthcare Services in Albuquerque, New Mexico a Lean Six Sigma team identified the reasons for noncompliance were multifaceted. The team followed the DMAIC process and completed the methodology in 12 months. They implemented multiple solutions in the three areas: Education, Culture, and Environment. Based on methicillin-resistant Staphylococcus aureus (MRSA) mortality research the team's results included an estimated 2.5 lives saved by reducing MRSA infections by 51%. Subsequently this 51% decrease in MRSA saved the hospital US$276,500. For those readers tasked with increasing hand hygiene compliance this article will provide the knowledge and insight needed to overcome multifaceted barriers to noncompliance.

  13. Antibodies Against Glycolipids Enhance Antifungal Activity of Macrophages and Reduce Fungal Burden After Infection with Paracoccidioides brasiliensis

    PubMed Central

    Bueno, Renata A.; Thomaz, Luciana; Muñoz, Julian E.; da Silva, Cássia J.; Nosanchuk, Joshua D.; Pinto, Márcia R.; Travassos, Luiz R.; Taborda, Carlos P.

    2016-01-01

    Paracoccidioidomycosis is a fungal disease endemic in Latin America. Polyclonal antibodies to acidic glycosphingolipids (GSLs) from Paracoccidioides brasiliensis opsonized yeast forms in vitro increasing phagocytosis and reduced the fungal burden of infected animals. Antibodies to GSL were active in both prophylactic and therapeutic protocols using a murine intratracheal infection model. Pathological examination of the lungs of animals treated with antibodies to GSL showed well-organized granulomas and minimally damaged parenchyma compared to the untreated control. Murine peritoneal macrophages activated by IFN-γ and incubated with antibodies against acidic GSLs more effectively phagocytosed and killed P. brasiliensis yeast cells as well as produced more nitric oxide compared to controls. The present work discloses a novel target of protective antibodies against P. brasiliensis adding to other well-studied mediators of the immune response to this fungus. PMID:26870028

  14. Glibenclamide reduces pro-inflammatory cytokine production by neutrophils of diabetes patients in response to bacterial infection

    NASA Astrophysics Data System (ADS)

    Kewcharoenwong, Chidchamai; Rinchai, Darawan; Utispan, Kusumawadee; Suwannasaen, Duangchan; Bancroft, Gregory J.; Ato, Manabu; Lertmemongkolchai, Ganjana

    2013-11-01

    Type 2 diabetes mellitus is a major risk factor for melioidosis, which is caused by Burkholderia pseudomallei. Our previous study has shown that polymorphonuclear neutrophils (PMNs) from diabetic subjects exhibited decreased functions in response to B. pseudomallei. Here we investigated the mechanisms regulating cytokine secretion of PMNs from diabetic patients which might contribute to patient susceptibility to bacterial infections. Purified PMNs from diabetic patients who had been treated with glibenclamide (an ATP-sensitive potassium channel blocker for anti-diabetes therapy), showed reduction of interleukin (IL)-1β and IL-8 secretion when exposed to B. pseudomallei. Additionally, reduction of these pro-inflammatory cytokines occurred when PMNs from diabetic patients were treated in vitro with glibenclamide. These findings suggest that glibenclamide might be responsible for the increased susceptibility of diabetic patients, with poor glycemic control, to bacterial infections as a result of its effect on reducing IL-1β production by PMNs.

  15. A lean Six Sigma team increases hand hygiene compliance and reduces hospital-acquired MRSA infections by 51%.

    PubMed

    Carboneau, Clark; Benge, Eddie; Jaco, Mary T; Robinson, Mary

    2010-01-01

    A low hand hygiene compliance rate by healthcare workers increases hospital-acquired infections to patients. At Presbyterian Healthcare Services in Albuquerque, New Mexico a Lean Six Sigma team identified the reasons for noncompliance were multifaceted. The team followed the DMAIC process and completed the methodology in 12 months. They implemented multiple solutions in the three areas: Education, Culture, and Environment. Based on methicillin-resistant Staphylococcus aureus (MRSA) mortality research the team's results included an estimated 2.5 lives saved by reducing MRSA infections by 51%. Subsequently this 51% decrease in MRSA saved the hospital US$276,500. For those readers tasked with increasing hand hygiene compliance this article will provide the knowledge and insight needed to overcome multifaceted barriers to noncompliance. PMID:20618572

  16. An experimental Helicobacter suis infection causes gastritis and reduced daily weight gain in pigs.

    PubMed

    De Bruyne, Ellen; Flahou, Bram; Chiers, Koen; Meyns, Tom; Kumar, Smitha; Vermoote, Miet; Pasmans, Frank; Millet, Sam; Dewulf, Jeroen; Haesebrouck, Freddy; Ducatelle, Richard

    2012-12-01

    Helicobacter suis is a zoonotically important bacterium, that has been associated with gastritis and ulcerative lesions of the pars oesophagea of the stomach in pigs. Its exact role in these pathologies, however, still remains controversial. Therefore, a total of 29 medicated early weaned piglets were inoculated intragastrically or orally, with a total of 2 × 10(9) viable H. suis bacteria and the effect on gastric pathology and weight gain was determined. Twenty-three medicated early weaned piglets were inoculated with a sterile culture medium and used as sham-inoculated controls. The animals were euthanized between 28 and 42 days after inoculation. Infected animals showed a more severe gastritis compared to the control group. There was also a significant reduction of approximately 60 g per day (10%) in weight gain in H. suis inoculated animals compared to the sham-inoculated control animals. In conclusion, this study demonstrates for the first time that a pure in vitro culture of H. suis not only causes gastritis but also a marked decrease of the daily weight gain in experimentally infected pigs.

  17. Deletion of the AcMNPV core gene ac109 results in budded virions that are non-infectious

    SciTech Connect

    Fang Minggang; Nie, Yingchao; Theilmann, David A.

    2009-06-20

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 is a core gene and its function in the virus life cycle is unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac109 deletion virus (vAc{sup 109KO}). Fluorescence and light microscopy showed that transfection of vAc{sup 109KO} results in a single-cell infection phenotype. Viral DNA replication is unaffected and the development of occlusion bodies in vAc{sup 109KO}-transfected cells evidenced progression to the very late phases of viral infection. Western blot and confocal immunofluorescence analysis showed that AC109 is expressed in the cytoplasm and nucleus throughout infection. In addition, AC109 is a structural protein as it was detected in both budded virus (BV) and occlusion derived virus in both the envelope and nucleocapsid fractions. Titration assays by qPCR and TCID{sub 50} showed that vAc{sup 109KO} produced BV but the virions are non-infectious. The vAc{sup 109KO} BV were indistinguishable from the BV of repaired and wild type control viruses as determined by negative staining and electron microscopy.

  18. Deletion of the AcMNPV core gene ac109 results in budded virions that are non-infectious.

    PubMed

    Fang, Minggang; Nie, Yingchao; Theilmann, David A

    2009-06-20

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 is a core gene and its function in the virus life cycle is unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac109 deletion virus (vAc(109KO)). Fluorescence and light microscopy showed that transfection of vAc(109KO) results in a single-cell infection phenotype. Viral DNA replication is unaffected and the development of occlusion bodies in vAc(109KO)-transfected cells evidenced progression to the very late phases of viral infection. Western blot and confocal immunofluorescence analysis showed that AC109 is expressed in the cytoplasm and nucleus throughout infection. In addition, AC109 is a structural protein as it was detected in both budded virus (BV) and occlusion derived virus in both the envelope and nucleocapsid fractions. Titration assays by qPCR and TCID(50) showed that vAc(109KO) produced BV but the virions are non-infectious. The vAc(109KO) BV were indistinguishable from the BV of repaired and wild type control viruses as determined by negative staining and electron microscopy.

  19. Modulation of a Pore in the Capsid of JC Polyomavirus Reduces Infectivity and Prevents Exposure of the Minor Capsid Proteins

    PubMed Central

    Nelson, Christian D. S.; Ströh, Luisa J.; Gee, Gretchen V.; O'Hara, Bethany A.; Stehle, Thilo

    2015-01-01

    ABSTRACT JC polyomavirus (JCPyV) infection of immunocompromised individuals results in the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). The viral capsid of JCPyV is composed primarily of the major capsid protein virus protein 1 (VP1), and pentameric arrangement of VP1 monomers results in the formation of a pore at the 5-fold axis of symmetry. While the presence of this pore is conserved among polyomaviruses, its functional role in infection or assembly is unknown. Here, we investigate the role of the 5-fold pore in assembly and infection of JCPyV by generating a panel of mutant viruses containing amino acid substitutions of the residues lining this pore. Multicycle growth assays demonstrated that the fitness of all mutants was reduced compared to that of the wild-type virus. Bacterial expression of VP1 pentamers containing substitutions to residues lining the 5-fold pore did not affect pentamer assembly or prevent association with the VP2 minor capsid protein. The X-ray crystal structures of selected pore mutants contained subtle changes to the 5-fold pore, and no other changes to VP1 were observed. Pore mutant pseudoviruses were not deficient in assembly, packaging of the minor capsid proteins, or binding to cells or in transport to the host cell endoplasmic reticulum. Instead, these mutant viruses were unable to expose VP2 upon arrival to the endoplasmic reticulum, a step that is critical for infection. This study demonstrated that the 5-fold pore is an important structural feature of JCPyV and that minor modifications to this structure have significant impacts on infectious entry. IMPORTANCE JCPyV is an important human pathogen that causes a severe neurological disease in immunocompromised individuals. While the high-resolution X-ray structure of the major capsid protein of JCPyV has been solved, the importance of a major structural feature of the capsid, the 5-fold pore, remains poorly understood. This pore is conserved across

  20. Members of the HCMV US12 family of predicted heptaspanning membrane proteins have unique intracellular distributions, including association with the cytoplasmic virion assembly complex

    SciTech Connect

    Das, Subhendu; Pellett, Philip E. . E-mail: pelletp@ccf.org

    2007-05-10

    The human cytomegalovirus (HCMV) US12 gene family is a group of 10 predicted seven-transmembrane domain proteins that have some features in common with G-protein-coupled receptors. Little is known of their patterns of expression, localization, or functional interactions. Here, we studied the intracellular localization of three US12 family members, US14, US17, and US18, with respect to various intracellular markers and the cytoplasmic virion assembly compartment (AC). The three proteins have distinct patterns of expression, which include associations with the AC. US14 is often distributed in a uniform granular manner throughout the cytoplasm, concentrating in the AC in some cells. US17 is expressed in a segmented manner, with its N-terminal domain localizing to the periphery of what we show here to be the AC and the C-terminal domain localizing to nuclei and the cytoplasm [Das, S., Skomorovska-Prokvolit, Y., Wang, F. Z., Pellett, P.E., 2006. Infection-dependent nuclear localization of US17, a member of the US12 family of human cytomegalovirus-encoded seven-transmembrane proteins. J. Virol. 80, 1191-1203]. Here, we show that the C-terminal domain is present at the center of the AC, in close association with markers of early endosomes; the N-terminal staining corresponds to an area stained by markers for the Golgi and trans-Golgi. US18 is distributed throughout the cytoplasm, concentrating in the AC at later stages of infection; it is localized more to the periphery of the AC than are US14 and US17C, in association with markers of the trans-Golgi. Although not detected in virions, their structures and localization in various zones within the AC suggest possible roles for these proteins in the process of virion maturation and egress.

  1. Detection of Receptor-Induced Glycoprotein Conformational Changes on Enveloped Virions by Using Confocal Micro-Raman Spectroscopy

    PubMed Central

    Lu, Xiaonan; Liu, Qian; Benavides-Montano, Javier A.; Nicola, Anthony V.; Aston, D. Eric; Rasco, Barbara A.

    2013-01-01

    Conformational changes in the glycoproteins of enveloped viruses are critical for membrane fusion, which enables viral entry into cells and the pathological cell-cell fusion (syncytia) associated with some viral infections. However, technological capabilities for identifying viral glycoproteins and their conformational changes on actual enveloped virus surfaces are generally scarce, challenging, and time-consuming. Our model, Nipah virus (NiV), is a syncytium-forming biosafety level 4 pathogen with a high mortality rate (40 to 75%) in humans. Once the NiV attachment glycoprotein (G) (NiV-G) binds the cell receptor ephrinB2 or -B3, G triggers conformational changes in the fusion glycoprotein (F) that result in membrane fusion and viral entry. We demonstrate that confocal micro-Raman spectroscopy can, within minutes, simultaneously identify specific G and F glycoprotein signals and receptor-induced conformational changes in NiV-F on NiV virus-like particles (VLPs). First, we identified reproducible G- and F-specific Raman spectral features on NiV VLPs containing M (assembly matrix protein), G, and/or F or on NiV/vesicular stomatitis virus (VSV) pseudotyped virions via second-derivative transformations and principal component analysis (PCA). Statistical analyses validated our PCA models. Dynamic temperature-induced conformational changes in F and G or receptor-induced target membrane-dependent conformational changes in F were monitored in NiV pseudovirions in situ in real time by confocal micro-Raman spectroscopy. Advantageously, Raman spectroscopy can identify specific protein signals in relatively impure samples. Thus, this proof-of-principle technological development has implications for the rapid identification and biostability characterization of viruses in medical, veterinary, and food samples and for the analysis of virion glycoprotein conformational changes in situ during viral entry. PMID:23283947

  2. The Lettuce infectious yellows virus (LIYV)-encoded P26 is associated with plasmalemma deposits within LIYV-infected cells

    SciTech Connect

    Medina, V.; Sudarshana, M.R.; Tian, T.; Ralston, K.S.; Yeh, H.-H.; Falk, B.W. . E-mail: bwfalk@ucdavis.edu

    2005-03-15

    Cytological, immunological, and mutagenesis approaches were used to identify the viral factors associated with the formation of plasmalemma deposits (PLDs) in whole plants and protoplasts infected by Lettuce infectious yellows virus (LIYV). Transmission electron microscopy and immunogold labeling using polyclonal antibodies to four of the five LIYV RNA 2-encoded large proteins, capsid protein (CP), minor capsid protein (CPm), HSP70 homolog (HSP70h), and P59, showed specific labeling of LIYV virions or virion aggregates around the vesiculated membranous inclusions, but not PLDs in LIYV-infected Nicotiana benthamiana, Nicotiana clevelandii, Lactuca sativa, and Chenopodium murale plants, and Nicotiana tabacum protoplasts. In contrast, antibodies to the RNA 2-encoded P26 showed specific labeling of PLDs but not virions in both LIYV-infected plants and protoplasts. Virion-like particles (VLPs) were seen in protoplasts infected by all LIYV RNA 2 mutants except for the CP (major capsid protein) mutant. PLDs were more difficult to find in protoplasts, but were seen in protoplasts infected by the CP and CPm mutants, but not in protoplasts infected by the P26, HSP70h, or P59 mutants. Interestingly, although the CPm mutant showed VLPs and PLDs, the PLDs did not show associated virions/virion-like particles as was always observed for PLDs seen in protoplasts infected by wild-type LIYV. Immunoblot analyses performed on purified LIYV virions showed that P26 was not detected with purified virions, but was detected in the cell wall, 1000 g and 30,000 g pellet fractions of LIYV-infected plants. These data suggest that P26 is associated with the LIYV-induced PLDs, and in contrast to the other RNA 2-encoded large proteins, P26 is not a virion protein.

  3. Wound Edge Protectors in Open Abdominal Surgery to Reduce Surgical Site Infections: A Systematic Review and Meta-Analysis

    PubMed Central

    Mihaljevic, André L.; Müller, Tara C.; Kehl, Victoria; Friess, Helmut; Kleeff, Jörg

    2015-01-01

    Importance Surgical site infections remain one of the most frequent complications following abdominal surgery and cause substantial costs, morbidity and mortality. Objective To assess the effectiveness of wound edge protectors in open abdominal surgery in reducing surgical site infections. Evidence Review A systematic literature search was conducted according to a prespecified review protocol in a variety of data-bases combined with hand-searches for randomized controlled trials on wound edge protectors in patients undergoing laparotomy. A qualitative and quantitative analysis of included trials was conducted. Findings We identified 16 randomized controlled trials including 3695 patients investigating wound edge protectors published between 1972 and 2014. Critical appraisal uncovered a number of methodological flaws, predominantly in the older trials. Wound edge protectors significantly reduced the rate of surgical site infections (risk ratio 0.65; 95%CI, 0.51–0.83; p = 0.0007; I2 = 52%). The results were robust in a number of sensitivity analyses. A similar effect size was found in the subgroup of patients undergoing colorectal surgery (risk ratio 0.65; 95%CI, 0.44–0.97; p = 0.04; I2 = 56%). Of the two common types of wound protectors double ring devices were found to exhibit a greater protective effect (risk ratio 0.29; 95%CI, 0.15–0.55) than single-ring devices (risk ratio 0.71; 95%CI, 0.54–0.92), but this might largely be due to the lower quality of available data for double-ring devices. Exploratory subgroup analyses for the degree of contamination showed a larger protective effect in contaminated cases (0.44; 95%CI, 0.28–0.67; p = 0.0002, I2 = 23%) than in clean-contaminated surgeries (0.72, 95%CI, 0.57–0.91; p = 0.005; I2 = 46%) and a strong effect on the reduction of superficial surgical site infections (risk ratio 0.45; 95%CI, 0.24–0.82; p = 0.001; I2 = 72%). Conclusions and Relevance Wound edge protectors significantly reduce the rate of

  4. Identification of a nonvirion protein of Aleutian disease virus: mink with Aleutian disease have antibody to both virion and nonvirion proteins.

    PubMed Central

    Bloom, M E; Race, R E; Wolfinbarger, J B

    1982-01-01

    We studied Aleutian disease virus polypeptides in Crandall feline kidney (CRFK) cells. When CRFK cells labeled with [35S]methionine at 60 h postinfection were studied by immunoprecipitation with sera from infected mink, the major Aleutian disease virus virion polypeptides (p85 and p75) were consistently identified, as was a 71,000-dalton nonvirion protein (p71). The peptide maps of p85 and p75 were similar, but the map of p71 was different. p85, p75, and p71 were all precipitated by sera from Aleutian disease virus-infected mink, including those with signs of progressive disease, but heterologous sera raised against purified Aleutian disease virus did not precipitate the nonvirion p71. These results indicated that the nonvirion p71 was unrelated to p85 and p75 and further suggested that mink infected with Aleutian disease virus develop antibody to nonvirion, as well as structural, viral proteins. Images PMID:6287034

  5. Overwintering Is Associated with Reduced Expression of Immune Genes and Higher Susceptibility to Virus Infection in Honey Bees.

    PubMed

    Steinmann, Nadja; Corona, Miguel; Neumann, Peter; Dainat, Benjamin

    2015-01-01

    The eusocial honey bee, Apis mellifera, has evolved remarkable abilities to survive extreme seasonal differences in temperature and availability of resources by dividing the worker caste into two groups that differ in physiology and lifespan: summer and winter bees. Most of the recent major losses of managed honey bee colonies occur during the winter, suggesting that winter bees may have compromised immune function and higher susceptibility to diseases. We tested this hypothesis by comparing the expression of eight immune genes and naturally occurring infection levels of deformed wing virus (DWV), one of the most widespread viruses in A. mellifera populations, between summer and winter bees. Possible interactions between immune response and physiological activity were tested by measuring the expression of vitellogenin and methyl farnesoate epoxidase, a gene coding for the last enzyme involved in juvenile hormone biosynthesis. Our data show that high DWV loads in winter bees correlate with reduced expression of genes involved in the cellular immune response and physiological activity and high expression of humoral immune genes involved in antibacterial defense compared with summer bees. This expression pattern could reflect evolutionary adaptations to resist bacterial pathogens and economize energy during the winter under a pathogen landscape with reduced risk of pathogenic viral infections. The outbreak of Varroa destructor infestation could have overcome these adaptations by promoting the transmission of viruses. Our results suggest that reduced cellular immune function during the winter may have increased honey bee's susceptibility to DWV. These results contribute to our understanding of honey bee colony losses in temperate regions.

  6. Reducing infection transmission in solid organ transplantation through donor nucleic acid testing: a cost-effectiveness analysis.

    PubMed

    Lai, J C; Kahn, J G; Tavakol, M; Peters, M G; Roberts, J P

    2013-10-01

    For solid organ transplant (SOT) donors, nucleic acid-amplification testing (NAT) may reduce human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission over antibody (Ab) testing given its shorter detection window period. We compared SOT donor NAT + Ab versus Ab alone using decision models to estimate incremental cost-effectiveness ratios (ICERs; cost per quality-adjusted life year [QALY] gained) from the societal perspective across a range of HIV/HCV prevalence values and NAT costs. The cost per QALY gained was calculated for two scenarios: (1) favorable: low cost ($150/donor)/high prevalence (HIV: 1.5%; HCV: 18.2%) and (2) unfavorable: high cost ($500/donor)/low prevalence (HIV: 0.1%; HCV: 1.5%). In the favorable scenario, adding NAT screening cost $161 013 per QALY gained for HIV was less costly) for HCV, and cost $86 653 per QALY gained for HIV/HCV combined. For the unfavorable scenario, the costs were $15 568 484, $221 006 and $10 077 599 per QALY gained, respectively. Universal HCV NAT + Ab for donors appears cost-effective to reduce infection transmission from SOT donors, while HIV NAT + Ab is not, except where HIV NAT is ≤$150/donor and prevalence is ≥1.5%. Our analyses provide important data to facilitate the decision to implement HIV and HCV NAT for deceased SOT donors and shape national policy regarding how to reduce infection transmission in SOT.

  7. Reducing Infection Transmission in Solid Organ Transplantation Through Donor Nucleic Acid Testing: A Cost-Effectiveness Analysis

    PubMed Central

    Lai, J. C.; Kahn, J. G.; Tavakol, M.; Peters, M. G.; Roberts, J. P.

    2014-01-01

    For solid organ transplant (SOT) donors, nucleic acid-amplification testing (NAT) may reduce human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission over antibody (Ab) testing given its shorter detection window period. We compared SOT donor NAT + Ab versus Ab alone using decision models to estimate incremental cost-effectiveness ratios (ICERs; cost per quality-adjusted life year [QALY] gained) from the societal perspective across a range of HIV/HCV prevalence values and NAT costs. The cost per QALY gained was calculated for two scenarios: (1) favorable: low cost ($150/donor)/high prevalence (HIV: 1.5%; HCV: 18.2%) and (2) unfavorable: high cost ($500/donor)/low prevalence (HIV: 0.1%; HCV: 1.5%). In the favorable scenario, adding NAT screening cost $161 013 per QALY gained for HIV was less costly) for HCV, and cost $86 653 per QALY gained for HIV/HCV combined. For the unfavorable scenario, the costs were $15 568 484, $221 006 and $10 077 599 per QALY gained, respectively. Universal HCV NAT + Ab for donors appears cost-effective to reduce infection transmission from SOT donors, while HIV NAT + Ab is not, except where HIV NAT is ≤$150/donor and prevalence is ≥1.5%. Our analyses provide important data to facilitate the decision to implement HIV and HCV NAT for deceased SOT donors and shape national policy regarding how to reduce infection transmission in SOT. PMID:24034208

  8. Transgenic shRNA pigs reduce susceptibility to foot and mouth disease virus infection.

    PubMed

    Hu, Shengwei; Qiao, Jun; Fu, Qiang; Chen, Chuangfu; Ni, Wei; Wujiafu, Sai; Ma, Shiwei; Zhang, Hui; Sheng, Jingliang; Wang, Pengyan; Wang, Dawei; Huang, Jiong; Cao, Lijuan; Ouyang, Hongsheng

    2015-01-01

    Foot-and-mouth disease virus (FMDV) is an economically devastating viral disease leading to a substantial loss to the swine industry worldwide. A novel alternative strategy is to develop pigs that are genetically resistant to infection. Here, we produce transgenic (TG) pigs that constitutively expressed FMDV-specific short interfering RNA (siRNA) derived from small hairpin RNA (shRNA). In vitro challenge of TG fibroblasts showed the shRNA suppressed viral growth. TG and non-TG pigs were challenged by intramuscular injection with 100 LD50 of FMDV. High fever, severe clinical signs of foot-and-mouth disease and typical histopathological changes were observed in all of the non-TG pigs but in none of the high-siRNA pigs. Our results show that TG shRNA can provide a viable tool for producing animals with enhanced resistance to FMDV. PMID:26090904

  9. Th2 responses without atopy: immunoregulation in chronic helminth infections and reduced allergic disease.

    PubMed

    Yazdanbakhsh, M; van den Biggelaar, A; Maizels, R M

    2001-07-01

    The immune response to helminth infections has long been known to share key features with the allergic response. In particular, both are typified by enhanced T helper 2 (Th2) responses with high levels of interleukin-4 (IL-4), IL-5 and IL-13, accompanied by eosinophilia and abundant IgE production. Paradoxically, the geographical distribution of helminth parasitism and allergic disease is complementary rather than coincident. Thus, the question arises does the Th2 response to parasites protect or pre-empt the host from developing Th2-linked allergic manifestations? It is suggested that downregulatory immune mechanisms, which dampen the anti-parasite response, might benefit the host by blocking progression to atopic reactions. This is of relevance in explaining how the "hygiene hypothesis" might operate immunologically and in the design of therapeutics. PMID:11429321

  10. Clinical implications of reduced susceptibility to fluoroquinolones in paediatric Shigella sonnei and Shigella flexneri infections

    PubMed Central

    Thompson, Corinne N.; Thieu, Nga Tran Vu; Vinh, Phat Voong; Duc, Anh Nguyen; Wolbers, Marcel; Vinh, Ha; Campbell, James I.; Ngoc, Dung Tran Thi; Hoang, Nguyen Van Minh; Thanh, Tuyen Ha; The, Hao Chung; Nguyen, To Nguyen Thi; Lan, Nguyen Phu Huong; Parry, Christopher M.; Chau, Nguyen Van Vinh; Thwaites, Guy; Thanh, Duy Pham; Baker, Stephen

    2016-01-01

    Objectives We aimed to quantify the impact of fluoroquinolone resistance on the clinical outcome of paediatric shigellosis patients treated with fluoroquinolones in southern Vietnam. Such information is important to inform therapeutic management for infections caused by this increasingly drug-resistant pathogen, responsible for high morbidity and mortality in young children globally. Methods Clinical information and bacterial isolates were derived from a randomized controlled trial comparing gatifloxacin with ciprofloxacin for the treatment of paediatric shigellosis. Time–kill experiments were performed to evaluate the impact of MIC on the in vitro growth of Shigella and Cox regression modelling was used to compare clinical outcome between treatments and Shigella species. Results Shigella flexneri patients treated with gatifloxacin had significantly worse outcomes than those treated with ciprofloxacin. However, the MICs of fluoroquinolones were not significantly associated with poorer outcome. The presence of S83L and A87T mutations in the gyrA gene significantly increased MICs of fluoroquinolones. Finally, elevated MICs and the presence of the qnrS gene allowed Shigella to replicate efficiently in vitro in high concentrations of ciprofloxacin. Conclusions We found that below the CLSI breakpoint, there was no association between MIC and clinical outcome in paediatric shigellosis infections. However, S. flexneri patients had worse clinical outcomes when treated with gatifloxacin in this study regardless of MIC. Additionally, Shigella harbouring the qnrS gene are able to replicate efficiently in high concentrations of ciprofloxacin and we hypothesize that such strains possess a competitive advantage against fluoroquinolone-susceptible strains due to enhanced shedding and transmission. PMID:26679253

  11. Afatinib Reduces STAT6 Signaling of Host ARPE-19 Cells Infected with Toxoplasma gondii

    PubMed Central

    Yang, Zhaoshou; Ahn, Hye-Jin; Park, Young-Hoon; Nam, Ho-Woo

    2016-01-01

    Specific gene expressions of host cells by spontaneous STAT6 phosphorylation are major strategy for the survival of intracellular Toxoplasma gondii against parasiticidal events through STAT1 phosphorylation by infection provoked IFN-γ. We determined the effects of small molecules of tyrosine kinase inhibitors (TKIs) on the growth of T. gondii and on the relationship with STAT1 and STAT6 phosphorylation in ARPE-19 cells. We counted the number of T. gondii RH tachyzoites per parasitophorous vacuolar membrane (PVM) after treatment with TKIs at 12-hr intervals for 72 hr. The change of STAT6 phosphorylation was assessed via western blot and immunofluorescence assay. Among the tested TKIs, Afatinib (pan ErbB/EGFR inhibitor, 5 µM) inhibited 98.0% of the growth of T. gondii, which was comparable to pyrimethamine (5 µM) at 96.9% and followed by Erlotinib (ErbB1/EGFR inhibitor, 20 µM) at 33.8% and Sunitinib (PDGFR or c-Kit inhibitor, 10 µM) at 21.3%. In the early stage of the infection (2, 4, and 8 hr after T. gondii challenge), Afatinib inhibited the phosphorylation of STAT6 in western blot and immunofluorescence assay. Both JAK1 and JAK3, the upper hierarchical kinases of cytokine signaling, were strongly phosphorylated at 2 hr and then disappeared entirely after 4 hr. Some TKIs, especially the EGFR inhibitors, might play an important role in the inhibition of intracellular replication of T. gondii through the inhibition of the direct phosphorylation of STAT6 by T. gondii. PMID:26951976

  12. Virion proteins and the perspectives of gene manipulations in vaccine preparation.

    PubMed

    Tickhonenko, T I

    1985-05-01

    The achievements and perspectives of genetic manipulations are described aiming at preparation of first generation subunit vaccines based on the synthesis in bacterial and eukaryotic cells of full-sized virion proteins expressing the main antigenic determinants. The preparation of such vaccines in bacterial cells seems out of perspective in the case of influenza, human hepatitis B, foot- and - mouth disease and some other viruses due to the peculiarities of structure and synthesis as well as low immunogenicity of the monomeric form of virion polypeptides. However, biotechnological procedures using eukaryotic cells and higher eukaryotic vectors and in part also yeast cells allowed to obtain full-sized virion proteins in a highly immunogenic state with good effects.

  13. 5' termini of poliovirus RNA: difference between virion and nonencapsidated 35S RNA.

    PubMed Central

    Fernandez-Muñoz, R; Lavi, U

    1977-01-01

    Poliovirus cytoplasmic, nonencapsidated 35S RNA yields approximately one pUp per molecule upon T2 RNase digestion, indicating that this RNA has the same 5' end as the polyribosome-associated viral RNA fraction. Double-stranded, replicative form RNA after the same treatment yielded approximately four pNp structures per molecule, 65% of which was pUp. In contrast, the 35S RNA from mature virions contained no detectable pNp, indicating that the 5' end of the virion RNA is different from that of the nonencapsidated RNA. None of the above molecules contained pppNp, ppNp, or GpppNp structures present in host mRNA. The virion RNA molecules, as we have shown previously for thenonencapsidated 35S viral RNA (Fernandez-Muñoz and Darnell, 1976), is not labeled with [methyl-3H]methionine. PMID:189096

  14. Mason-Pfizer monkey virus: analysis and localization of virion proteins and glycoproteins.

    PubMed Central

    Schochetman, G; Kortright, K; Schlom, J

    1975-01-01

    The polypeptide composition of Mason-Pfizer monkey virus was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Six major polypeptides of molecular weights 68,000, 27,000, 20,000, 14,000, 12,000, and 10,000 were resolved regardless of the cell type (i.e., two human and two rhesus) in which the virus was grown. Protein gp68 (68,000) represented the major virus glycoprotein and protein gp20 (20,000) represented a minor glycoprotein of the virion, again regardless of the cell type of origin of the virus. Protein gp68 appears to be located on the outer surface of the viral envelope, as demonstrated by lactoperoxidase catalyzed iodination of intact virions. Additional glycoproteins were shown to be virion associated; their presence depended, however, on the cell type in which the virus was propagated. PMID:810603

  15. Early events of polyoma infection: adsorption, penetration and nuclear transport

    NASA Technical Reports Server (NTRS)

    Consigli, R. A.; Haynes, J. I. Jr; Chang, D.; Grenz, L.; Richter, D.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Polyoma virions have different attachment proteins which are responsible for hemagglutination of erythrocytes and attachment to cultured mouse kidney cells (MKC). Virion binding studies demonstrated that MKC possess specific (productive infection) and nonspecific (nonproductive) receptors. Empty polyoma capsids have hemagglutination activity and bind to non-specific MKC receptors, but they are not capable of competing for specific virion cell receptors or preventing productive infection. Isoelectric focusing of the virion major capsid protein, VP1, separated this protein into six species (A through F). These species had identical amino acid sequences, but differed in degree of modification (phosphorylation, acetylation, sulfation and hydroxylation). Evidence based upon precipitation with specific antisera supports the view that VP1 species E is required for specific adsorption and that D and F are required for hemagglutination. The virion attachment domain has been localized to an 18 kilodalton fragment of the C-terminal region of VP1. Monopinocytotic vesicles containing 125I-labeled polyoma virions were isolated from infected MKC. A crosslinker was used to bind the MKC cell receptor(s) covalently to VP1 attachment protein, and a new 120 kilodalton band was identified by SDS-PAGE. An anti-idiotype antibody prepared against a neutralizing polyoma monoclonal antiody was used to identify a putative 50 kilodalton receptor protein from a detergent extract of MKC, as well as from MKC membrane preparation.

  16. Killing Two Birds with One Stone: Natural Rice Rhizospheric Microbes Reduce Arsenic Uptake and Blast Infections in Rice

    PubMed Central

    Lakshmanan, Venkatachalam; Cottone, Jonathon; Bais, Harsh P.

    2016-01-01

    Our recent work has shown that a rice thizospheric natural isolate, a Pantoea sp (hereafter EA106) attenuates Arsenic (As) uptake in rice. In parallel, yet another natural rice rhizospheric isolate, a Pseudomonas chlororaphis (hereafter EA105), was shown to inhibit rice blast pathogen Magnaporthe oryzae. Considering the above, we envisaged to evaluate the importance of mixed stress regime in rice plants subjected to both As toxicity and blast infections. Plants subjected to As regime showed increased susceptibility to blast infections compared to As-untreated plants. Rice blast pathogen M. oryzae showed significant resistance against As toxicity compared to other non-host fungal pathogens. Interestingly, plants treated with EA106 showed reduced susceptibility against blast infections in plants pre-treated with As. This data also corresponded with lower As uptake in plants primed with EA106. In addition, we also evaluated the expression of defense related genes in host plants subjected to As treatment. The data showed that plants primed with EA106 upregulated defense-related genes with or without As treatment. The data shows the first evidence of how rice plants cope with mixed stress regimes. Our work highlights the importance of natural association of plant microbiome which determines the efficacy of benign microbes to promote the development of beneficial traits in plants. PMID:27790229

  17. Infection-induced behavioural changes reduce connectivity and the potential for disease spread in wild mice contact networks

    PubMed Central

    Lopes, Patricia C.; Block, Per; König, Barbara

    2016-01-01

    Infection may modify the behaviour of the host and of its conspecifics in a group, potentially altering social connectivity. Because many infectious diseases are transmitted through social contact, social connectivity changes can impact transmission dynamics. Previous approaches to understanding disease transmission dynamics in wild populations were limited in their ability to disentangle different factors that determine the outcome of disease outbreaks. Here we ask how social connectivity is affected by infection and how this relationship impacts disease transmission dynamics. We experimentally manipulated disease status of wild house mice using an immune challenge and monitored social interactions within this free-living population before and after manipulation using automated tracking. The immune-challenged animals showed reduced connectivity to their social groups, which happened as a function of their own behaviour, rather than through conspecific avoidance. We incorporated these disease-induced changes of social connectivity among individuals into models of disease outbreaks over the empirically-derived networks. The models revealed that changes in host behaviour frequently resulted in the disease being contained to very few animals, as opposed to becoming widespread. Our results highlight the importance of considering the role that behavioural alterations during infection can have on social dynamics when evaluating the potential for disease outbreaks. PMID:27548906

  18. Infection-induced behavioural changes reduce connectivity and the potential for disease spread in wild mice contact networks.

    PubMed

    Lopes, Patricia C; Block, Per; König, Barbara

    2016-01-01

    Infection may modify the behaviour of the host and of its conspecifics in a group, potentially altering social connectivity. Because many infectious diseases are transmitted through social contact, social connectivity changes can impact transmission dynamics. Previous approaches to understanding disease transmission dynamics in wild populations were limited in their ability to disentangle different factors that determine the outcome of disease outbreaks. Here we ask how social connectivity is affected by infection and how this relationship impacts disease transmission dynamics. We experimentally manipulated disease status of wild house mice using an immune challenge and monitored social interactions within this free-living population before and after manipulation using automated tracking. The immune-challenged animals showed reduced connectivity to their social groups, which happened as a function of their own behaviour, rather than through conspecific avoidance. We incorporated these disease-induced changes of social connectivity among individuals into models of disease outbreaks over the empirically-derived networks. The models revealed that changes in host behaviour frequently resulted in the disease being contained to very few animals, as opposed to becoming widespread. Our results highlight the importance of considering the role that behavioural alterations during infection can have on social dynamics when evaluating the potential for disease outbreaks. PMID:27548906

  19. Use of Trichoderma fungi in spray solutions to reduce Moniliophthora roreri infection of Theobroma cacao fruits in Northeastern Costa Rica.

    PubMed

    Seng, John; Herrera, Geovanny; Vaughan, Christopher S; McCoy, Michael B

    2014-09-01

    Cacao (Theobroma cacao) is an important cash crop in tropical climates such as that of Latin America. Over the past several decades, the infection of cultivated cacao by Moniliophthllora roreri, known commonly as "monilia", has significantly hindered cacao production in Latin America. Studies have proposed the use of Trichoderma sp. fungi in biocontrol treatments to prevent and reduce monilia infection, yet tests of Trichoderma-containing spray treatments on cacao agroforests have produced mixed results. Researchers and agricultural workers have suggested that addition of soil, fly ash, or other carbon sources to a Trichoderma spray may improve its efficacy in fighting monilia. To test these suggestions, we designed a series of spray mixtures including Thichoderma cultures, soil, and all necessary controls. We applied the spray mixtures to 80 cacao trees (20 trees for each of four resistant-selected clones to monilia) at the FINMAC organic cacao plantation in Pueblo Nuevo de Guacimo, Limón Province, in northeastern Costa Rica in March-April 2013. Five treatments were applied (control, water, water plus sterilized soil, water plus Trichoderma, and water plus sterilized soil plus Trichoderma). Each treatment was applied to four trees of each clone. We monitored the incidence of monilia infection under each spray treatment over the course of 35d. We found that spraying entire cacao trees two times with a mixture containing Trichoderma and sterilized soil significantly reduced the incidence of monilia infection by 11% (p ≤ 0.05) in only 35d, as compared to the control. This reduction in loss of cacao pods translates into an increase of plantation mean productivity of 1,500 kg dried beans/ha by 198 kg/ha up to 1,698 kg/ha or by a total increase over the whole 110 ha plantation by 21,780 kg. We propose that using such an antifungal spray over the whole course of a crop cycle (120 days) would decrease infection incidence even more. Application of this fungal control

  20. Use of Trichoderma fungi in spray solutions to reduce Moniliophthora roreri infection of Theobroma cacao fruits in Northeastern Costa Rica.

    PubMed

    Seng, John; Herrera, Geovanny; Vaughan, Christopher S; McCoy, Michael B

    2014-09-01

    Cacao (Theobroma cacao) is an important cash crop in tropical climates such as that of Latin America. Over the past several decades, the infection of cultivated cacao by Moniliophthllora roreri, known commonly as "monilia", has significantly hindered cacao production in Latin America. Studies have proposed the use of Trichoderma sp. fungi in biocontrol treatments to prevent and reduce monilia infection, yet tests of Trichoderma-containing spray treatments on cacao agroforests have produced mixed results. Researchers and agricultural workers have suggested that addition of soil, fly ash, or other carbon sources to a Trichoderma spray may improve its efficacy in fighting monilia. To test these suggestions, we designed a series of spray mixtures including Thichoderma cultures, soil, and all necessary controls. We applied the spray mixtures to 80 cacao trees (20 trees for each of four resistant-selected clones to monilia) at the FINMAC organic cacao plantation in Pueblo Nuevo de Guacimo, Limón Province, in northeastern Costa Rica in March-April 2013. Five treatments were applied (control, water, water plus sterilized soil, water plus Trichoderma, and water plus sterilized soil plus Trichoderma). Each treatment was applied to four trees of each clone. We monitored the incidence of monilia infection under each spray treatment over the course of 35d. We found that spraying entire cacao trees two times with a mixture containing Trichoderma and sterilized soil significantly reduced the incidence of monilia infection by 11% (p ≤ 0.05) in only 35d, as compared to the control. This reduction in loss of cacao pods translates into an increase of plantation mean productivity of 1,500 kg dried beans/ha by 198 kg/ha up to 1,698 kg/ha or by a total increase over the whole 110 ha plantation by 21,780 kg. We propose that using such an antifungal spray over the whole course of a crop cycle (120 days) would decrease infection incidence even more. Application of this fungal control

  1. The vaginal microbiome, vaginal anti-microbial defence mechanisms and the clinical challenge of reducing infection-related preterm birth.

    PubMed

    Witkin, S S

    2015-01-01

    Ascending bacterial infection is implicated in about 40-50% of preterm births. The human vaginal microbiota in most women is dominated by lactobacilli. In women whose vaginal microbiota is not lactobacilli-dominated anti-bacterial defence mechanisms are reduced. The enhanced proliferation of pathogenic bacteria plus degradation of the cervical barrier increase bacterial passage into the endometrium and amniotic cavity and trigger preterm myometrial contractions. Evaluation of protocols to detect the absence of lactobaciili dominance in pregnant women by self-measuring vaginal pH, coupled with measures to promote growth of lactobacilli are novel prevention strategies that may reduce the occurrence of preterm birth in low-resource areas. PMID:25316066

  2. Efficacy of Infection Control Interventions in Reducing the Spread of Multidrug-Resistant Organisms in the Hospital Setting

    PubMed Central

    D'Agata, Erika M. C.; Horn, Mary Ann; Ruan, Shigui; Webb, Glenn F.; Wares, Joanna R.

    2012-01-01

    Multidrug-resistant organisms (MDRO) continue to spread in hospitals globally, but the population-level impact of recommended preventive strategies and the relative benefit of individual strategies targeting all MDRO in the hospital setting are unclear. To explore the dynamics of MDRO transmission in the hospital, we develop a model extending data from clinical individual-level studies to quantify the impact of hand hygiene, contact precautions, reducing antimicrobial exposure and screening surveillance cultures in decreasing the prevalence of MDRO colonization and infection. The effect of an ongoing increase in the influx of patients colonized with MDRO into the hospital setting is also quantified. We find that most recommended strategies have substantial effect in decreasing the prevalence of MDRO over time. However, screening for asymptomatic MDRO colonization among patients who are not receiving antimicrobials is of minimal value in reducing the spread of MDRO. PMID:22363420

  3. No evidence that presence of sexually transmitted infection selects for reduced mating rate in the two spot ladybird, Adalia bipunctata

    PubMed Central

    Jones, Sophie L.; Pastok, Daria

    2015-01-01

    Sexually transmitted infections (STIs) are common in animals and plants, and frequently impair individual fertility. Theory predicts that natural selection will favour behaviours that reduce the chance of acquiring a STI. We investigated whether an STI, Coccipolipus hippodamiae has selected for increased rejection of mating by female Adalia bipunctata as a mechanism to avoid exposure. We first demonstrated that rejection of mating by females did indeed reduce the chance of acquiring the mite. We then examined whether rejection rate and mating rate differed between ladybirds from mite-present and mite-absent populations when tested in a common environment. No differences in rejection intensity or remating propensity were observed between the two populations. We therefore conclude there is no evidence that STIs have driven the evolution of female mating behaviour in this species. PMID:26290801

  4. A multi-strain Synbiotic may reduce viral respiratory infections in asthmatic children: a randomized controlled trial

    PubMed Central

    Ahanchian, Hamid; Jafari, Seyed Ali; Ansari, Elham; Ganji, Toktam; Kiani, Mohammad Ali; Khalesi, Maryam; Momen, Tooba; Kianifar, Hamidreza

    2016-01-01

    prednisolone use, outpatient visits, or hospital admissions. Conclusion This new synbiotic (a mixture of seven probiotic strains plus fructooligosacharide may reduce episodes of viral infection in asthmatic children. Trial registration This study is registered in Iranian Registry of Clinical Trials with registration number of IRCT201509234976N3. Funding This research was supported financially by the Research Council of Mashhad University of Medical Sciences (Grant Number: 911048). PMID:27790333

  5. Arbuscular mycorrhizal fungi reduce growth and infect roots of the non-host plant Arabidopsis thaliana.

    PubMed

    Veiga, Rita S L; Faccio, Antonella; Genre, Andrea; Pieterse, Corné M J; Bonfante, Paola; van der Heijden, Marcel G A

    2013-11-01

    The arbuscular mycorrhizal (AM) symbiosis is widespread throughout the plant kingdom and important for plant nutrition and ecosystem functioning. Nonetheless, most terrestrial ecosystems also contain a considerable number of non-mycorrhizal plants. The interaction of such non-host plants with AM fungi (AMF) is still poorly understood. Here, in three complementary experiments, we investigated whether the non-mycorrhizal plant Arabidopsis thaliana, the model organism for plant molecular biology and genetics, interacts with AMF. We grew A. thaliana alone or together with a mycorrhizal host species (either Trifolium pratense or Lolium multiflorum) in the presence or absence of the AMF Rhizophagus irregularis. Plants were grown in a dual-compartment system with a hyphal mesh separating roots of A. thaliana from roots of the host species, avoiding direct root competition. The host plants in the system ensured the presence of an active AM fungal network. AM fungal networks caused growth depressions in A. thaliana of more than 50% which were not observed in the absence of host plants. Microscopy analyses revealed that R. irregularis supported by a host plant was capable of infecting A. thaliana root tissues (up to 43% of root length colonized), but no arbuscules were observed. The results reveal high susceptibility of A. thaliana to R. irregularis, suggesting that A. thaliana is a suitable model plant to study non-host/AMF interactions and the biological basis of AM incompatibility.

  6. Social Capital and Women's Reduced Vulnerability to HIV infection in Rural Zimbabwe

    PubMed Central

    GREGSON, SIMON; MUSHATI, PHYLLIS; GRUSIN, HARRY; NHAMO, MERCY; SCHUMACHER, CHRISTINA; SKOVDAL, MORTEN; NYAMUKAPA, CONSTANCE; CAMPBELL, CATHERINE

    2012-01-01

    Social capital - especially through its ‘network’ dimension (high levels of participation in local community groups) - is thought to be an important determinant of health in many contexts. We investigate its effect on HIV prevention, using prospective data from a general population cohort in eastern Zimbabwe spanning a period of extensive behaviour change (1998-2003). Almost half of the initially uninfected women interviewed were members of at least one community group. In an ecological analysis of 88 communities, those with higher levels of community group participation had lower incidence of new HIV infections and more had adopted safer behaviours, although these effects were largely accounted for by differences in socio-demographic composition. Individual women in community groups had lower HIV incidence and more extensive behaviour change, even after controlling for confounding factors. Community group membership was not associated with lower HIV incidence in men, possibly reflecting a propensity amongst men to participate in groups that allow them to develop and demonstrate their masculine identities – often at the expense of their health. Support for women’s community groups could be an effective HIV prevention strategy in countries with large-scale HIV epidemics. PMID:22066129

  7. Environmental control in tea fields to reduce infection by Pseudomonas syringae pv. theae.

    PubMed

    Tomihama, T; Nonaka, T; Nishi, Y; Arai, K

    2009-02-01

    Bacterial shoot blight (BSB) disease, caused by Pseudomonas syringae pv. theae, is a major bacterial disease of tea plants in Japan. BSB mainly occurs in the low-temperature season, and lesion formation by P. syringae pv. theae is enhanced by both low temperature and the presence of ice nucleation-active Xanthomonas campestris (INAX), which catalyzes ice formation at -2 to -4 degrees C and is frequently co-isolated with P. syringae pv. theae from tea plants. Low temperature is thus the most important environmental factor influencing the incidence of BSB; however, the effects of low temperature on infection of the host by P. syringae pv. theae and of environmental controls in fields on the occurrence of the disease are poorly understood. In this study, we show that ice formation on tea leaves by INAX enhanced P. syringae pv. theae invasion into leaf tissue. The natural incidence of BSB in the field was closely related to early autumn frost. Frost protection in late autumn, which prevented ice formation on tea plants, significantly decreased the incidence of BSB, and frost protection combined with bactericide application held the incidence under the economic threshold level. Our data indicate that environmental control in the field based on microbial interactions in the host offers a new strategy for plant disease control. PMID:19159313

  8. Social capital and women's reduced vulnerability to HIV infection in rural Zimbabwe.

    PubMed

    Gregson, Simon; Mushati, Phyllis; Grusin, Harry; Nhamo, Mercy; Schumacher, Christina; Skovdal, Morten; Nyamukapa, Constance; Campbell, Catherine

    2011-01-01

    Social capital—especially through its “network” dimension (high levels of participation in local community groups)—is thought to be an important determinant of health in many contexts. We investigate its effect on HIV prevention, using prospective data from a general population cohort in eastern Zimbabwe spanning a period of extensive behavior change (1998–2003). Almost half of the initially uninfected women interviewed were members of at least one community group. In an analysis of 88 communities, individuals with higher levels of community group participation had lower incidence of new HIV infections and more of them had adopted safer behaviors, although these effects were largely accounted for by differences in socio-demographic composition. Individual women in community groups had lower HIV incidence and more extensive behavior change, even after controlling for confounding factors. Community group membership was not associated with lower HIV incidence in men, possibly refecting a propensity among men to participate in groups that allow them to develop and demonstrate their masculine identities—often at the expense of their health. Support for women's community groups could be an effective HIV prevention strategy in countries with large-scale HIV epidemics. PMID:22066129

  9. Mass drug administration of azithromycin for trachoma reduces the prevalence of genital Chlamydia trachomatis infection in the Solomon Islands

    PubMed Central

    Bottomley, C; Tome, H; Pitakaka, R; Butcher, R; Sokana, O; Kako, H; Solomon, A W; Mabey, D C

    2016-01-01

    Objectives Chlamydia trachomatis is the most common bacterial sexually transmitted infection and is frequently asymptomatic; ocular C. trachomatis strains cause trachoma. Mass drug administration (MDA) of azithromycin for trachoma might also reduce the prevalence of genital C. trachomatis. In a survey conducted in the Solomon Islands in 2014, prior to MDA, the prevalence of genital C. trachomatis was 20.3% (95% CI 15.9% to 25.4%). We conducted a survey to establish the impact of MDA with azithromycin on genital C. trachomatis. Methods Women attending three community outpatient clinics, predominantly for antenatal care, 10 months after MDA with azithromycin given for trachoma elimination, were enrolled in this survey. Self-taken high vaginal swabs were for C. trachomatis and Neisseria gonorrhoeae using the BD Probetec strand displacement assay. Results 298 women were enrolled. C. trachomatis infection was diagnosed in 43 women (14.4%, 95% CI 10.6% to 18.9%) and N. gonorrhoeae in 9 (3%, 95% CI 1.4% to 5.7%). The age-adjusted OR for C. trachomatis infection was consistent with a significant decrease in the prevalence of C. trachomatis following MDA (OR 0.58, 95% CI 0.37 to 0.94, p=0.027). There was no change in the prevalence of N. gonorrhoeae between following MDA (OR 0.51, 95% CI 0.22 to 1.22, p=0.13). Conclusions This study demonstrated a 40% reduction in the age-adjusted prevalence of genital C. trachomatis infection following azithromycin MDA for trachoma elimination. PMID:26888658

  10. Frequent Dental Scaling Is Associated with a Reduced Risk of Periprosthetic Infection following Total Knee Arthroplasty: A Nationwide Population-Based Nested Case-Control Study

    PubMed Central

    Tai, Ta-Wei; Lin, Tzu-Chieh; Ho, Chia-Jung; Kao Yang, Yea-Huei; Yang, Chyun-Yu

    2016-01-01

    Oral bacteremia has been presumed to be an important risk factor for total knee arthroplasty (TKA) infection. We aimed to investigate whether dental scaling could reduce the risk of TKA infection. A nested case-control study was conducted to compare 1,291 TKA patients who underwent resection arthroplasty for infected TKA and 5,004 matched controls without infection in the TKA cohort of Taiwan’s National Health Insurance Research Database (NHIRD). The frequency of dental scaling was analyzed. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection. The percentage of patients who received dental scaling was higher in the control group than in the TKA infection group. The risk for TKA infection was 20% lower for patients who received dental scaling at least once within a 3-year period than for patients who never received dental scaling. Moreover, the risk of TKA infection was reduced by 31% among patients who underwent more frequent dental scaling (5–6 times within 3 years). Frequent and regular dental scaling is associated with a reduced risk of TKA infection. PMID:27336912

  11. Frequent Dental Scaling Is Associated with a Reduced Risk of Periprosthetic Infection following Total Knee Arthroplasty: A Nationwide Population-Based Nested Case-Control Study.

    PubMed

    Tai, Ta-Wei; Lin, Tzu-Chieh; Ho, Chia-Jung; Kao Yang, Yea-Huei; Yang, Chyun-Yu

    2016-01-01

    Oral bacteremia has been presumed to be an important risk factor for total knee arthroplasty (TKA) infection. We aimed to investigate whether dental scaling could reduce the risk of TKA infection. A nested case-control study was conducted to compare 1,291 TKA patients who underwent resection arthroplasty for infected TKA and 5,004 matched controls without infection in the TKA cohort of Taiwan's National Health Insurance Research Database (NHIRD). The frequency of dental scaling was analyzed. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection. The percentage of patients who received dental scaling was higher in the control group than in the TKA infection group. The risk for TKA infection was 20% lower for patients who received dental scaling at least once within a 3-year period than for patients who never received dental scaling. Moreover, the risk of TKA infection was reduced by 31% among patients who underwent more frequent dental scaling (5-6 times within 3 years). Frequent and regular dental scaling is associated with a reduced risk of TKA infection. PMID:27336912

  12. Case Study: Nutritional and Lifestyle Support to Reduce Infection Incidence in an International-Standard Premier League Soccer Player.

    PubMed

    Ranchordas, Mayur K; Bannock, Laurent; Robinson, Scott L

    2016-04-01

    Professional soccer players are exposed to large amounts of physiological and psychological stress, which can increase infection risk and threaten availability for training and competition. Accordingly, it is important for practitioners to implement strategies that support player well-being and prevent illness. This case study demonstrates how a scientifically supported and practically applicable nutrition and lifestyle strategy can reduce infection incidence in an illness-prone professional soccer player. In the 3 months before the intervention, the player had 3 upper-respiratory tract infections (URTIs) and subsequently missed 3 competitive matches and 2 weeks' training. He routinely commenced morning training sessions in the fasted state and was estimated to be in a large daily energy deficit. Throughout the 12-week intervention, the amount, composition, and timing of energy intake was altered, quercetin and vitamin D were supplemented, and the player was provided with a daily sleep and hygiene protocol. There was a positive increase in serum vitamin D 25(OH) concentration from baseline to Week 12 (53 n·mol-1 to 120 n·mol-1) and salivary immunoglobulin-A (98 mg·dl-1 to 135 mg·dl-1), as well as a decline in the number of URTI symptoms (1.8 ± 2.0 vs. 0.25 ± 0.5 for Weeks 0-4 and Weeks 8-12, respectively). More important, he maintained availability for all training and matches over the 12-week period. We offer this case study as a real-world applied example for other players and practitioners seeking to deploy nutrition and lifestyle strategies to reduce risk of illness and maximize player availability. PMID:26479983

  13. Mapping in vitro local material properties of intact and disrupted virions at high resolution using multi-harmonic atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Cartagena, Alexander; Hernando-Pérez, Mercedes; Carrascosa, José L.; de Pablo, Pedro J.; Raman, Arvind

    2013-05-01

    Understanding the relationships between viral material properties (stiffness, strength, charge density, adhesion, hydration, viscosity, etc.), structure (protein sub-units, genome, surface receptors, appendages), and functions (self-assembly, stability, disassembly, infection) is of significant importance in physical virology and nanomedicine. Conventional Atomic Force Microscopy (AFM) methods have measured a single physical property such as the stiffness of the entire virus from nano-indentation at a few points which severely limits the study of structure-property-function relationships. We present an in vitro dynamic AFM technique operating in the intermittent contact regime which synthesizes anharmonic Lorentz-force excited AFM cantilevers to map quantitatively at nanometer resolution the local electro-mechanical force gradient, adhesion, and hydration layer viscosity within individual φ29 virions. Furthermore, the changes in material properties over the entire φ29 virion provoked by the local disruption of its shell are studied, providing evidence of bacteriophage depressurization. The technique significantly generalizes recent multi-harmonic theory (A. Raman, et al., Nat. Nanotechnol., 2011, 6, 809-814) and enables high-resolution in vitro quantitative mapping of multiple material properties within weakly bonded viruses and nanoparticles with complex structure that otherwise cannot be observed using standard AFM techniques.Understanding the relationships between viral material properties (stiffness, strength, charge density, adhesion, hydration, viscosity, etc.), structure (protein sub-units, genome, surface receptors, appendages), and functions (self-assembly, stability, disassembly, infection) is of significant importance in physical virology and nanomedicine. Conventional Atomic Force Microscopy (AFM) methods have measured a single physical property such as the stiffness of the entire virus from nano-indentation at a few points which severely limits the

  14. The use of microencapsulated hepatocytes transplantation reduces mortality and liver alterations in Schistosoma mansoni infected hamsters.

    PubMed

    Sherif, Soad A; Moharib, Mona N; El-Lakkany, Naglaa M; Hammam, Olfat A; Salman, Fatma H; El-Naggar, Mohamed M

    2014-04-01

    Hepatocyte transplantation is an attractive therapeutic modality for liver disease as an alternative for orthotropic liver transplantation. The goal of this work was to study the adequacy of intrasplenic hepatocyte transplantation (HCTx) in fresh and microencapsulated forms, in a hamster model of liver fibrosis by Schistosoma mansoni infected hamsters were divided into 6 groups; untreated for 11 weeks (GI) and for 15 weeks (GII), treated with praziquantel (PZQ) 7 weeks PI, and killed 4 weeks (GIII) and 8 weeks (GIV) post-treatment. Treated with PZQ 7 weeks PI, and then treated orally with immunosuppressive drug "cyclosporine (4 weeks post PZQ treatment), 24 hr. before interasplenic injection with fresh hepatocytes (V). Treated with PZQ 7 weeks PI, and then injected interasplenically (4 weeks post-treatment) with microencapsulated hepatocytes (GVI). GI & GIII were killed 11 weeks PI for assessment the anti-schistosomal efficacy of PZQ. The other four groups were killed 15 weeks PI for investigation of liver and spleen histology, serum liver enzymes and hepatic oxidative markers before and after HCTx. Freshly isolated hepatocytes with a mean viability 92.97 +/- 1.2% were used for microencapsulation and transplantation. Histological study showed the presence of transplanted hepatocytes in spleen of recipient. PZQ accelerated healing of hepatic granulomatous lesions as evidenced parasitologically by the increase in the percentage of dead eggs and histologically showing more granuloma circumscription with more ova degeneration and less inflammatory cells. The 25-day survival rates in GII, GIV, GV& GVI were 5/15 (33.3%), 8/15 (53.3%), 10/15 (66.7%) and 9/15 (60%) respectively. In addition, there were significantly better outcomes in serum biochemical indexes such as ALT, AST, gamma-GT, ALP, and hepatic SOD and MDA in the fresh and microencapsulated groups than in PZQ-treated group, without great differences between the microencapsulated and the fresh transplanted groups

  15. Expanded syringe exchange programs and reduced HIV infection among new injection drug users in Tallinn, Estonia

    PubMed Central

    2011-01-01

    Background Estonia has experienced an HIV epidemic among intravenous drug users (IDUs) with the highest per capita HIV prevalence in Eastern Europe. We assessed the effects of expanded syringe exchange programs (SEP) in the capital city, Tallinn, which has an estimated 10,000 IDUs. Methods SEP implementation was monitored with data from the Estonian National Institute for Health Development. Respondent driven sampling (RDS) interview surveys with HIV testing were conducted in Tallinn in 2005, 2007 and 2009 (involving 350, 350 and 327 IDUs respectively). HIV incidence among new injectors (those injecting for < = 3 years) was estimated by assuming (1) new injectors were HIV seronegative when they began injecting, and (2) HIV infection occurred at the midpoint between first injection and time of interview. Results SEP increased from 230,000 syringes exchanged in 2005 to 440,000 in 2007 and 770,000 in 2009. In all three surveys, IDUs were predominantly male (80%), ethnic Russians (>80%), and young adults (mean ages 24 to 27 years). The proportion of new injectors decreased significantly over the years (from 21% in 2005 to 12% in 2009, p = 0.005). HIV prevalence among all respondents stabilized at slightly over 50% (54% in 2005, 55% in 2007, 51% in 2009), and decreased among new injectors (34% in 2005, 16% in 2009, p = 0.046). Estimated HIV incidence among new injectors decreased significantly from 18/100 person-years in 2005 and 21/100 person-years in 2007 to 9/100 person-years in 2009 (p = 0.026). Conclusions In Estonia, a transitional country, a decrease in the HIV prevalence among new injectors and in the numbers of people initiating injection drug use coincided with implementation of large-scale SEPs. Further reductions in HIV transmission among IDUs are still required. Provision of 70 or more syringes per IDU per year may be needed before significant reductions in HIV incidence occur. PMID:21718469

  16. The use of microencapsulated hepatocytes transplantation reduces mortality and liver alterations in Schistosoma mansoni infected hamsters.

    PubMed

    Sherif, Soad A; Moharib, Mona N; El-Lakkany, Naglaa M; Hammam, Olfat A; Salman, Fatma H; El-Naggar, Mohamed M

    2014-04-01

    Hepatocyte transplantation is an attractive therapeutic modality for liver disease as an alternative for orthotropic liver transplantation. The goal of this work was to study the adequacy of intrasplenic hepatocyte transplantation (HCTx) in fresh and microencapsulated forms, in a hamster model of liver fibrosis by Schistosoma mansoni infected hamsters were divided into 6 groups; untreated for 11 weeks (GI) and for 15 weeks (GII), treated with praziquantel (PZQ) 7 weeks PI, and killed 4 weeks (GIII) and 8 weeks (GIV) post-treatment. Treated with PZQ 7 weeks PI, and then treated orally with immunosuppressive drug "cyclosporine (4 weeks post PZQ treatment), 24 hr. before interasplenic injection with fresh hepatocytes (V). Treated with PZQ 7 weeks PI, and then injected interasplenically (4 weeks post-treatment) with microencapsulated hepatocytes (GVI). GI & GIII were killed 11 weeks PI for assessment the anti-schistosomal efficacy of PZQ. The other four groups were killed 15 weeks PI for investigation of liver and spleen histology, serum liver enzymes and hepatic oxidative markers before and after HCTx. Freshly isolated hepatocytes with a mean viability 92.97 +/- 1.2% were used for microencapsulation and transplantation. Histological study showed the presence of transplanted hepatocytes in spleen of recipient. PZQ accelerated healing of hepatic granulomatous lesions as evidenced parasitologically by the increase in the percentage of dead eggs and histologically showing more granuloma circumscription with more ova degeneration and less inflammatory cells. The 25-day survival rates in GII, GIV, GV& GVI were 5/15 (33.3%), 8/15 (53.3%), 10/15 (66.7%) and 9/15 (60%) respectively. In addition, there were significantly better outcomes in serum biochemical indexes such as ALT, AST, gamma-GT, ALP, and hepatic SOD and MDA in the fresh and microencapsulated groups than in PZQ-treated group, without great differences between the microencapsulated and the fresh transplanted groups

  17. Infection.

    PubMed

    Saigal, Gaurav; Nagornaya, Natalya; Post, M Judith D

    2016-01-01

    Imaging is useful in the diagnosis and management of infections of the central nervous system. Typically, imaging findings at the outset of the disease are subtle and nonspecific, but they often evolve to more definite imaging patterns in a few days, with less rapidity than for stroke but faster than for neoplastic lesions. This timing is similar to that of noninfectious inflammatory brain disease, such as multiple sclerosis. Fortunately, imaging patterns help to distinguish the two kinds of processes. Other than for sarcoidosis, the meninges are seldom involved in noninfectious inflammation; in contrast, many infectious processes involve the meninges, which then enhance with contrast on computed tomography (CT) or magnetic resonance imaging (MRI). However, brain infection causes a vast array of imaging patterns. Although CT is useful when hemorrhage or calcification is suspected or bony detail needs to be determined, MRI is the imaging modality of choice in the investigation of intracranial infections. Imaging sequences such as diffusion-weighted imaging help in accurately depicting the location and characterizing pyogenic infections and are particularly useful in differentiating bacterial infections from other etiologies. Susceptibility-weighted imaging is extremely useful for the detection of hemorrhage. Although MR spectroscopy findings can frequently be nonspecific, certain conditions such as bacterial abscesses show a relatively specific spectral pattern and are useful in diagnosing and constituting immediate therapy. In this chapter we review first the imaging patterns associated with involvement of various brain structures, such as the epidural and subdural spaces, the meninges, the brain parenchyma, and the ventricles. Involvement of these regions is illustrated with bacterial infections. Next we illustrate the patterns associated with viral and prion diseases, followed by mycobacterial and fungal infections, to conclude with a review of imaging findings

  18. Incomplete but Infectious Vaccinia Virions Are Produced in the Absence of Oncolysis in Feline SCCF1 Cells

    PubMed Central

    Parviainen, Suvi; Autio, Karoliina; Vähä-Koskela, Markus; Guse, Kilian; Pesonen, Sari; Rosol, Thomas J.; Zhao, Fang; Hemminki, Akseli

    2015-01-01

    Vaccinia virus is a large, enveloped virus of the poxvirus family. It has broad tropism and typically virus replication culminates in accumulation and lytic release of intracellular mature virus (IMV), the most abundant form of infectious virus, as well as release by budding of extracellular enveloped virus (EEV). Vaccinia viruses have been modified to replicate selectively in cancer cells and clinically tested as oncolytic agents. During preclinical screening of relevant cancer targets for a recombinant Western Reserve strain deleted for both copies of the thymidine kinase and vaccinia growth factor genes, we noticed that confluent monolayers of SCCF1 cat squamous carcinoma cells were not destroyed even after prolonged infection. Interestingly, although SCCF1 cells were not killed, they continuously secreted virus into the cell culture supernatant. To investigate this finding further, we performed detailed studies by electron microscopy. Both intracellular and secreted virions showed morphological abnormalities on ultrastructural inspection, suggesting compromised maturation and morphogenesis of vaccinia virus in SCCF1 cells. Our data suggest that SCCF1 cells produce a morphologically abnormal virus which is nevertheless infective, providing new information on the virus-host cell interactions and intracellular biology of vaccinia virus. PMID:25799430

  19. Incomplete but infectious vaccinia virions are produced in the absence of oncolysis in feline SCCF1 cells.

    PubMed

    Parviainen, Suvi; Autio, Karoliina; Vähä-Koskela, Markus; Guse, Kilian; Pesonen, Sari; Rosol, Thomas J; Zhao, Fang; Hemminki, Akseli

    2015-01-01

    Vaccinia virus is a large, enveloped virus of the poxvirus family. It has broad tropism and typically virus replication culminates in accumulation and lytic release of intracellular mature virus (IMV), the most abundant form of infectious virus, as well as release by budding of extracellular enveloped virus (EEV). Vaccinia viruses have been modified to replicate selectively in cancer cells and clinically tested as oncolytic agents. During preclinical screening of relevant cancer targets for a recombinant Western Reserve strain deleted for both copies of the thymidine kinase and vaccinia growth factor genes, we noticed that confluent monolayers of SCCF1 cat squamous carcinoma cells were not destroyed even after prolonged infection. Interestingly, although SCCF1 cells were not killed, they continuously secreted virus into the cell culture supernatant. To investigate this finding further, we performed detailed studies by electron microscopy. Both intracellular and secreted virions showed morphological abnormalities on ultrastructural inspection, suggesting compromised maturation and morphogenesis of vaccinia virus in SCCF1 cells. Our data suggest that SCCF1 cells produce a morphologically abnormal virus which is nevertheless infective, providing new information on the virus-host cell interactions and intracellular biology of vaccinia virus.

  20. Furin cleavage of the SARS coronavirus spike glycoprotein enhances cell-cell fusion but does not affect virion entry

    SciTech Connect

    Follis, Kathryn E.; York, Joanne; Nunberg, Jack H. . E-mail: jack.nunberg@umontana.edu

    2006-07-05

    The fusogenic potential of Class I viral envelope glycoproteins is activated by proteloytic cleavage of the precursor glycoprotein to generate the mature receptor-binding and transmembrane fusion subunits. Although the coronavirus (CoV) S glycoproteins share membership in this class of envelope glycoproteins, cleavage to generate the respective S1 and S2 subunits appears absent in a subset of CoV species, including that responsible for the severe acute respiratory syndrome (SARS). To determine whether proteolytic cleavage of the S glycoprotein might be important for the newly emerged SARS-CoV, we introduced a furin recognition site at single basic residues within the putative S1-S2 junctional region. We show that furin cleavage at the modified R667 position generates discrete S1 and S2 subunits and potentiates membrane fusion activity. This effect on th