970 resultados para HERPES SIMPLEX VIRUS
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The mechanisms responsible for cytokine-mediated antiviral effects are not fully understood. We approached this problem by studying the outcome of intraocular herpes simplex (HSV) infection in transgenic mice that express interferon gamma in the photoreceptor cells of the retina. These transgenic mice showed selective survival from lethal HSV-2 infection manifested in both eyes, the optic nerve, and the brain. Although transgenic mice developed greater inflammatory responses to the virus in the eyes, inflammation and viral titers in their brains were equivalent to nontransgenic mice. However, survival of transgenic mice correlated with markedly lower numbers of central neurons undergoing apoptosis. The protooncogene Bcl2 was found to be induced in the HSV-2-infected brains of transgenic mice, allowing us to speculate on its role in fostering neuronal survival in this model. These observations imply a complex interaction between cytokine, virus, and host cellular factors. Our results suggest a cytokine-regulated salvage pathway that allows for survival of infected neurons.
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BACKGROUND Over 3500 HIV-positive women give birth annually in Ukraine, a setting with high prevalence of sexually transmitted infections. Herpes simplex virus Type 2 (HSV-2) co-infection may increase HIV mother-to-child transmission (MTCT) risk. We explored factors associated with HSV-2 seropositivity among HIV-positive women in Ukraine, and its impact on HIV MTCT. METHODS Data on 1513 HIV-positive women enrolled in the Ukraine European Collaborative Study from 2007 to 2012 were analysed. Poisson and logistic regression models respectively were fit to investigate factors associated with HSV-2 seropositivity and HIV MTCT. RESULTS Median maternal age was 27 years (IQR 24-31), 53% (796/1513) had been diagnosed with HIV during their most recent pregnancy and 20% had a history of injecting drugs. Median antenatal CD4 count was 430 cells/mm(3) (IQR 290-580). Ninety-six percent had received antiretroviral therapy antenatally. HSV-2 seroprevalence was 68% (1026/1513). In adjusted analyses, factors associated with HSV-2 antibodies were history of pregnancy termination (APR 1.30 (95% CI 1.18-1.43) for ≥ 2 vs. 0), having an HIV-positive partner (APR 1.15 (95% CI 1.05-1.26) vs partner's HIV status unknown) and HCV seropositivity (APR 1.23 (95 % CI 1.13-1.35)). The overall HIV MTCT rate was 2.80% (95% CI 1.98-3.84); no increased HIV MTCT risk was detected among HSV-2 seropositive women after adjusting for known risk factors (AOR 1.43 (95% CI 0.54-3.77). CONCLUSION No increased risk of HIV MTCT was detected among the 68% of HIV-positive women with antibodies to HSV-2, in this population with an overall HIV MTCT rate of 2.8%. Markers of ongoing sexual risk among HIV-positive HSV-2 seronegative women indicate the importance of interventions to prevent primary HSV-2 infection during pregnancy in this high-risk group.
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At present there is not a reliable vaccine against herpes virus. Viral protein vaccines as yet have proved unsuccessful to meet the challenge of raising an appropriate immune response. Cantab Pharmaceuticals has produced a virus vaccine that can undergo one round of replication in the recipient in order to produce a more specific immune reaction. This virus is called Disabled Infectious Single Cycle Herpes Simplex Virus (DISC HSV) which has been derived by deleting the essential gH gene from a type 2 herpes virus. This vaccine has been proven to be effective in animal studies. Existing methods for the purification of viruses rely on laboratory techniques and for vaccine production would be on a far too small a scale. There is therefore a need for new virus purification methods to be developed in order to meet these large scale needs. An integrated process for the manufacture of a purified recombinant DISC HSV is described. The process involves culture of complementing Vero (CR2) cells, virus infection and manufacture, virus harvesting and subsequent downstream processing. The identification of suitable growth parameters for the complementing cell line and optimal limes for both infection and harvest are addressed. Various traditional harvest methods were investigated and found not to be suitable for a scaled up process. A method of harvesting, that exploits the elution of cell associated viruses by the competitive binding of exogenous heparin to virus envelope gC proteins, is described and is shown to yield significantly less contaminated process streams than sonication or osmotic approaches that involve cell rupture (with> 10-fold less complementing cell protein). High concentrations of salt (>0.8M NaCl) exhibit the same effect, although the high osmotic strength ruptures cells and increase the contamination of the process stream. This same heparin-gC protein affinity interaction is also shown to provide an efficient adsorptive purification procedure for herpes viruses which avoids the need to pre-treat the harvest material, apart from clarification, prior to chromatography. Subsequent column eluates provide product fractions with a 100-fold increase in virus titre and low levels of complementing cell protein and DNA (0.05 pg protein/pfu and 1.2 x 104 pg DNA/pfu respectively).
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Purpose: To investigate whether UL43 protein, which is highly conserved in alpha- and gamma herpes viruses, and a non-glycosylated transmembrane protein, is involved in virus entry and virus-induced cell fusion. Methods: Mutagenesis was accomplished by a markerless two-step Red recombination mutagenesis system implemented on the Herpes simplex virus 1 (HSV-1) bacterial artificial chromosome (BAC). Growth properties of HSV-1 UL43 mutants were analyzed using plaque morphology and one-step growth kinetics. SDS-PAGE and Western blot was employed to assay the synthesis of the viral glycoproteins. Virus-penetration was assayed to determine if UL43 protein is required for efficient virus entry. Results: Lack of UL43 expression resulted in significantly reduced plaque sizes of syncytial mutant viruses and inhibited cell fusion induced by gBΔ28 or gKsyn20 (p < 0.05). Deletion of UL43 did not affect overall expression levels of viral glycoproteins gB, gC, gD, and gH on HSV-1(F) BAC infected cell surfaces. Moreover, mutant viruses lacking UL43 gene exhibited slower kinetics of entry into Vero cells than the parental HSV-1(F) BAC. Conclusion: Thus, these results suggest an important role for UL43 protein in mediating virus-induced membrane fusion and efficient entry of virion into target cells.
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Four glycoproteins (gD, gB, gH, and gL) are required for herpes simplex virus (HSV) entry into the cell and for cell-cell fusion in transfected cells. gD serves as the receptor-binding glycoprotein and as the trigger of fusion; the other three glycoproteins execute fusion between the viral envelope and the plasma or endocytic membranes. Little is known on the interaction of gD with gB, gH, and gL. Here, the interactions between herpes simplex virus gD and its nectin1 receptor or between gD, gB, and gH were analyzed by complementation of the N and C portions of split enhanced green fluorescent protein (EGFP) fused to the glycoproteins. Split EGFP complementation was detected between proteins designated gDN + gHC, gDN + gBC, and gHN + gBC + wtgD, both in cells transfected with two or tree glycoproteins and in cells transfected with the four glycoproteins, commited to form syncytia. The in situ assay provides evidence that gD interacts with gH and gB independently one of the other. We further document the interaction between gH and gB. To elucidate which portions of the glycoproteins interact with each other we generated mutants of gD and gB. gD triggers fusion through a specialised domain, named pro-fusion domain (PFD), located C-terminally in the ectodomain. Here, we show that PFD is made of subdomains 1 and 2 (amino acids 260–285 and 285–310) and that each one partially contributed to herpes simplex virus infectivity. Chimeric gB molecules composed of HSV and human herpesvirus 8 (HHV8) sequences failed to reach the cell surface and to complement a gB defective virus. By means of pull down experiments we analyzed the interactions of HSV-HHV8 gB chimeras with gH or gD fused to the strep-tag. The gB sequence between aa residues 219-360 was identified as putative region of interaction with gH or critical to the interaction.
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Herpes simplex virus entry into cells requires a multipartite fusion apparatus made of gD, gB and heterodimer gH/gL. gD serves as receptor-binding glycoprotein and trigger of fusion; its ectodomain is organized in a N-terminal domain carrying the receptor-binding sites, and a C-terminal domain carrying the profusion domain, required for fusion but not receptor-binding. gB and gH/gL execute fusion. To understand how the four glycoproteins cross-talk to each other we searched for biochemical defined complexes in infected and transfected cells, and in virions. We report that gD formed complexes with gB in absence of gH/gL, and with gH/gL in absence of gB. Complexes with similar composition were formed in infected and transfected cells. They were also present in virions prior to entry, and did not increase at virus fusion with cell. A panel of gD mutants enabled the preliminary location of part of the binding site in gD to gB to the aa 240-260 portion and downstream, with T306P307 as critical residues, and of the binding site to gH/gL at aa 260-310 portion, with P291P292 as critical residues. The results indicate that gD carries composite independent binding sites for gB and gH/gL, both of which partly located in the profusion domain. The second part of the project dealt with rational design of peptides inhibiting virus entry has been performed. Considering gB and gD, the crystal structure is known, so we designed peptides that dock in the structure or prevent the adoption of the final conformation of target molecule. Considering the other glycoproteins, of which the structure is not known, peptide libraries were analyzed. Among several peptides, some were identified as active, designed on glycoprotein B. Two of them were further analyzed. We identified peptide residues fundamental for the inhibiting activity, suggesting a possible mechanism of action. Furthermore, changing the flexibility of peptides, an increased activity was observed,with an EC50 under 10μM. New approaches will try to demonstrate the direct interaction between these peptides and the target glycoprotein B.
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Sexually transmitted diseases (STDs) are among the largest public health problems, especially in developing countries. The acquisition of these infections during early sexual activity is common and many infections have a benign course. However, in some pathogens remain in the state of latency can be reactivated and cause productive infection that may progress to severe forms. In addition, some of them are transmitted vertically resulting in congenital infection, causing immediate damage or long-term child. The classic risk factors for sexually transmitted agents are: early onset of sexual and reproductive health, multiple sexual partners throughout life, use of oral contraceptives and co-infections with different pathogens. We present the results of a cross-sectional study aimed to estimate the prevalence of genital infection by human papillomavirus (HPV), Herpes simplex virus (HSV) and Chlamydia trachomatis (CT) in a segment of the female population of the metropolitan area Christmas, among those who enrolled voluntarily sought, Basic Health Units for the examination of cancer screening cervix in the period 2008 to 2010. All participants, a total of 261 women answered a standard questionnaire by which identified the socio-demographic characteristics, classical risk factors for STDs, reproductive and sexual activity and smoking. Of each patient were obtained two samples, one for the completion of the Pap test for detection of cellular changes and the other processed for DNA extraction and analyzed by PCR (polymerase chain reaction) to detect the three pathogens studied. The population of the study was composed of sexually active women aged between 13 and 79 years, mean 38.7 years, most of them being married, low education levels and low incomes. The majority (87%) had normal results on cytology and only 2.7% had low-grade cytological abnormalities. Prevalence rates were 37.9% for HPV, 4.6% for CT and 26% for HSV. HPV prevalence was higher in women under 25, unmarried and in those who had multiple sexual partners. Women with simultaneous infection by HSV-1 and 2 had higher prevalence of HPV infection. The prevalence of HSV infection showed no association whatsoever with the risk factors analyzed and HSV-1 was the predominant type among the cases of genital HSV infection. The overall prevalence of C. Trachomatis was relatively low, thus providing greater value in younger women aged less than or equal to 20 years
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Due to lack of effective therapy, primary brain tumors are the focus of intense investigation of novel experimental approaches that use vectors and recombinant viruses. Therapeutic approaches have been both indirect, whereby vectors are used, or direct to allow for direct cell killing by the introduced virus. Genetically engineered herpes simplex viruses are currently being evaluated as an experimental approach to eradicate malignant human gliomas. Initial studies with gamma (1)34.5 mutants, R3616 (from which both copies of the gamma (1)34.5 gene have been deleted) and R4009 (a construct with two stop codons inserted into the gamma (1)34.5 gene), have been assessed. In a syngeneic scid mouse intracranial tumor model, recombinant herpes simplex virus can be experimentally used for the treatment of brain tumors. These viruses and additional engineered viruses were subsequently tested in human glioma cells both in vitro and in vivo. Using a xenogeneic scid mouse intracranial glioma model, R4009 therapy of established tumors significantly prolonged survival. Most importantly, long-term survival was achieved, with histologic evidence that R4009 eradicated intracranial tumors in this model. Furthermore, the opportunity to evaluate gamma (1)34.5 mutants that have enhanced oncolytic activity, e.g., R8309 where the carboxyl terminus of the gamma (1)34.5 gene has been replaced by the murine homologue, MyD116, are considered.
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A bottlenose dolphin, stranded in the Canary Islands in 2001 exhibited non-suppurative encephalitis. No molecular detection of cetacean morbillivirus (CeMV) was found, but a herpesviral-specific band of 250 bp was detected in the lung and brain. The sequenced herpesviral PCR product was compared with GenBank sequences, obtaining 98% homology (p-distance of 0.02) with Human herpesvirus 1 (herpes simplex virus 1 or HSV-1). This is the first report of a herpes simplex-like infection in a stranded dolphin.
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Tesis (Maestría en Ciencias con Orientación Terminal en Biología Molecular e Ingeniería Genética) UANL, 2012.
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Herpes-simplex- und Varizella-zoster-Viren sind die häufigsten Ursachen viraler Keratitiden. Bei chronisch rezidivierendem Verlauf entstehen oft visuslimitierende Komplikationen. Typische Verlaufsformen sind die epitheliale Keratitis (dendritisch/geografisch), stromale Keratitis (infektiös und/oder immunologisch), Endotheliitis (disziform) und neurotrophe Keratopathie (metaherpetische Keratitis). Beim Zoster ophthalmicus kommt die Problematik der postherpetischen Neuralgie hinzu. Mit den verfügbaren Virustatika stehen potente Wirkstoffe zur Verfügung, auch zur Schubprophylaxe. Sobald immunologische Prozesse eine zentrale Rolle spielen, ist der gezielte Einsatz von topischen Kortikosteroiden oder Ciclosporin A notwendig. Der Epithelschluss kann mit Tränenersatzmitteln, Kontaktlinsen oder einer Amnionmembran-Transplantation unterstützt werden. Die Erfolgsrate von elektiven Keratoplastiken kann durch eine Langzeitprophylaxe mit systemischen Virustatika verbessert werden.
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Le virus herpès simplex de type 1 (HSV 1) affecte la majorité de la population mondiale. HSV 1 cause de multiples symptômes délétères dont les plus communs sont les lésions orofaciales usuellement appelées feux sauvages. Le virus peut aussi causer des effets plus sérieux comme la cécité ou des troubles neurologiques. Le virus réside de façon permanente dans le corps de son hôte. Malgré l’existence de nombreux traitements pour atténuer les symptômes causés par HSV 1, aucun médicament ne peut éliminer le virus. Dans le but d’améliorer les connaissances concernant le cycle viral de HSV 1, ce projet cible l’étude du transport du virus dans la cellule hôte. Ce projet aura permis la collecte d’informations concernant le modus operandi de HSV 1 pour sortir des compartiments cellulaires où il séjourne. Les différentes expérimentations ont permis de publier 3 articles dont un article qui a été choisi parmi les meilleurs papiers par les éditeurs de « Journal of Virology » ainsi qu’un 4e article qui a été soumis. Premièrement, un essai in vitro reproduisant la sortie de HSV 1 du noyau a été mis sur pied, via l’isolation de noyaux issus de cellules infectées. Nous avons démontré que tout comme dans les cellules entières, les capsides s’évadent des noyaux isolés dans l’essai in vitro en bourgeonnant avec la membrane nucléaire interne, puis en s’accumulant sous forme de capsides enveloppées entre les deux membranes nucléaires pour finalement être relâchées dans le cytoplasme exclusivement sous une forme non enveloppée. Ces observations appuient le modèle de transport de dé-enveloppement/ré-enveloppement. Deuxièmement, dans le but d’identifier des joueurs clefs viraux impliqués dans la sortie nucléaire du virus, les protéines virales associées aux capsides relâchées par le noyau ont été examinées. La morphologie multicouche du virus HSV 1 comprend un génome d’ADN, une capside, le tégument et une enveloppe. Le tégument est un ensemble de protéines virales qui sont ajoutées séquentiellement sur la particule virale. La séquence d’ajout des téguments de même que les sites intracellulaires où a lieu la tégumentation sont l’objet d’intenses recherches. L’essai in vitro a été utilisé pour étudier cette tégumentation. Les données recueillies suggèrent un processus séquentiel qui implique l’acquisition des protéines UL36, UL37, ICP0, ICP8, UL41, UL42, US3 et possiblement ICP4 sur les capsides relâchées par le noyau. Troisièmement, pour obtenir davantage d’informations concernant la sortie de HSV 1 des compartiments membranaires de la cellule hôte, la sortie de HSV 1 du réseau trans golgien (TGN) a aussi été étudiée. L’étude a révélé l’implication de la protéine kinase D cellulaire (PKD) dans le transport post-TGN de HSV 1. PKD est connue pour réguler le transport de petits cargos et son implication dans le transport de HSV 1 met en lumière l’utilisation d’une machinerie commune pour le transport des petits et gros cargos en aval du TGN. Le TGN n’est donc pas seulement une station de triage, mais est aussi un point de rencontre pour différentes voies de transport intracellulaire. Tous ces résultats contribuent à une meilleure compréhension du processus complexe de maturation du virus HSV 1, ce qui pourrait mener au développement de meilleurs traitements pour combattre le virus. Les données amassées concernant le virus HSV 1 pourraient aussi être appliquées à d’autres virus. En plus de leur pertinence dans le domaine de la virologie, les découvertes issues de ce projet apportent également de nouveaux détails au niveau du transport intracellulaire.