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Littérature scientifique sur le sujet « Viral antigen »

Auteur : Grafiati
Publié le 1 avril 2023

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Articles de revues sur le sujet "Viral antigen"

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Doan, Thu A., Johnathon Schafer, Erin D. Lucas et Beth Tamburini. « Antigen archiving promotes secondary CD8+ T cell memory responses during an unrelated infection ». Journal of Immunology 206, no 1_Supplement (1 mai 2021) : 102.06. http://dx.doi.org/10.4049/jimmunol.206.supp.102.06.

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Abstract Numerous studies have shown viral antigens can persist in lymph nodes after resolution of the infection. We showed that lymphatic endothelial cells (LECs), which comprise the lymphatic vasculature necessary for antigen drainage from the tissue, is the predominant cell type required for the persistence of antigen within the lymph node. We termed this process antigen archiving due the ability of LECs to actively archive antigens to which an immune response has occurred. This process involves antigen acquisition, retention, and exchange of the antigen between LECs and dendritic cells (DC), resulting in presentation of the archived antigens to CD8+ memory T cells and improving effector function. In more recent data, we demonstrated that LEC death causes the release of archived antigens during LN contraction. The objective of this study was to determine if during a secondary unrelated infection whether LEC death would occur and cause archived antigens to be released. As expected, we found that a second and unrelated viral infection causes LEC death within two to three weeks following infection. Within the same time frame that we observed LEC death, we observed a significant increase in archived antigen-specific endogenous memory T cells. This increase only occurred in mice that received an unrelated viral infection and not in those mice that did not receive the unrelated viral infection. In conclusion, archived antigen release during a secondary unrelated infection potentially boosts the archived antigen specific memory CD8+ T cell population. Understanding the mechanism of antigen release during multiple infections could ultimately lead to better strategies for vaccination and improve our understanding of how LECs influence immunity.
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Reignat, Stephanie, George J. M. Webster, David Brown, Graham S. Ogg, Abigail King, Suranjith L. Seneviratne, Geoff Dusheiko, Roger Williams, Mala K. Maini et Antonio Bertoletti. « Escaping High Viral Load Exhaustion ». Journal of Experimental Medicine 195, no 9 (6 mai 2002) : 1089–101. http://dx.doi.org/10.1084/jem.20011723.

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Deletion, anergy, and a spectrum of functional impairments can affect virus-specific CD8 cells in chronic viral infections. Here we characterize a low frequency population of CD8 cells present in chronic hepatitis B virus (HBV) infection which survive in the face of a high quantity of viral antigen. Although they do not appear to exert immunological pressure in vivo, these CD8 cells are not classically “tolerant” since they proliferate, lyse, and produce antiviral cytokines in vitro. They are characterized by altered HLA/peptide tetramer reactivity, which is not explained by TCR down-regulation or reduced functional avidity and which can be reversed with repetitive stimulation. CD8 cells with altered tetramer binding appear to have a specificity restricted to envelope antigen and not to other HBV antigens, suggesting that mechanisms of CD8 cell dysfunction are differentially regulated according to the antigenic form and presentation of individual viral antigens.
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Tewalt, Eric Franklin, Jean M. Grant, Erica L. Granger, Keri B. Donohue et Chris C. Norbury. « Viral Sequestration of Antigen Subverts Cross Priming (93.14) ». Journal of Immunology 178, no 1_Supplement (1 avril 2007) : S168. http://dx.doi.org/10.4049/jimmunol.178.supp.93.14.

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Abstract Antigens driven by poxvirus late promoters are produced in much larger quantities than those driven by early promoters both in vitro and in vivo. Despite the abundance of protein produced, antigens driven by late poxvirus promoters typically induce a low or undetectable CD8+ T cell response following immunization in vivo, while those driven by early promoters induce a significant response. We show that antigen driven by late promoters is not expressed in primary dendritic cells, preventing induction of naïve CD8+ T cells via the direct presentation pathway. However, it is puzzling why the cross priming pathway does not compensate for this lack of direct presentation as the relevance of the pathway is based upon its ability to induce CD8+ T cells in the absence of viral infection of DC or upon the expression of viral modulatory molecules that may prevent direct presentation. Our studies demonstrate that when present in similar quantities, late promoter driven antigen is not available for cross priming in vivo. In contrast, cellular antigen from virus-infected cells can access the cross priming pathway under comparable conditions. The mechanism involved does not require the shutoff of host cell protein synthesis but is due to the sequestration of late promoter driven antigen in viral factories inhibiting antigen donation to DC. This observation indicates a novel mechanism of viral evasion, whereby antigen is not available for use in either the direct or cross priming pathways.
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Ramakrishnan, Kamna, et Darren R. Flower. « Discriminating antigen and non-antigen using proteome dissimilarity II : viral and fungal antigens ». Bioinformation 5, no 1 (24 juin 2010) : 35–38. http://dx.doi.org/10.6026/97320630005035.

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Antonuk, A., O. Dyshkant et O. Nikitin. « ВИЗНАЧЕННЯ ТЕРМІНУ ЗБЕРІГАННЯ ТА СТАБІЛЬНОСТІ ІНФЕКЦІЙНОЇ АКТИВНОСТІ КУЛЬТУРАЛЬНИХ АНТИГЕНІВ ШТАМУ ГВК 1 Ж ТА КЛОНУ ГВК 2 ТТ ДЛЯ ПОСТАНОВКИ РДП ». Scientific Messenger of LNU of Veterinary Medicine and Biotechnology 18, no 3(70) (4 septembre 2016) : 8–13. http://dx.doi.org/10.15421/nvlvet7002.

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Getting a culture herpesviridae antigens first and second types is possible using cell cultures inoculated epithelial pig testicles and tracheal calf respectively. The incubation herpesviridae first and second types should be conducted on the above lines in cell culture incubator at a temperature of 37,5 °C for up to 10 days. To maximize the release of virus from cell culture fluid viral after incubation need three frozen at temperatures from –18 °C to + 20 °C. The resulting liquid is purified viral the culture by centrifugation. Determining the infectious activity of the culture liquid viral performed in response hemagglutination of horse erythrocytes suspension, and the material is titrated to 1: 128 in the two recurrence. Accounting reaction was performed at 2, 4, 6 and 8 hours. Infectious material volumetric activity was 1:4. Getting antigens envisages concentrating liquid viral culture fluid by reverse dialysis. To do this, conducted a study to identify the optimal concentration of antigen suitable for setting reaction diffusion precipitation. At 1:10 antigen concentration result of different reactions, depending on the account of the diffusion precipitation reactions. When concentration of EHV–1 antigen was found that the optimum dilution for its RDP is 1:20. In assessing the EHV–2 antigen, found that suitable for setting reaction diffusion precipitation RDP is an antigen concentrated from 1:60 to 1:20. In practical terms, most rational use of antigen, concentrated 20 times.Keeping culture antigens can be conducted frozen at minus 18 ° C, for 12 months because after six months of storage of the frozen infectious activity was not decreased. And in research in 12 months noted a line of precipitation in native samples and serum diluted 1:2. Working antigens for diffuse precipitation reaction must be sterile on various forms of bacteria and fungi. Therefore, samples of viral antigens were plated on agar culture media for general purpose (plain agar), after having spent preserving antigen using 0.01% solution mertiolyatu rate of 0.1 sm3/1sm3 culture fluid. Using such an environment can detect material in the test organisms belonging to different morphological groups. Research sterility subjected to viral antigens, herpesviridae infection on the first type of herpesviridae infection and the second type.
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Storset, A. K., Ø. Evensen et E. Rimstad. « Immunohistochemical Identification of Caprine Arthritis-Encephalitis Virus in Paraffin-embedded Specimens from Naturally Infected Goats ». Veterinary Pathology 34, no 3 (mai 1997) : 180–88. http://dx.doi.org/10.1177/030098589703400302.

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The expression of caprine arthritis-encephalitis virus capsid protein was studied in seropositive naturally infected asymptomatic goats (10), seropositive naturally infected encephalitic kids (12) and goats (4), and noninfected control goats (3). Rabbit antiserum to recombinant viral capsid and matrix proteins were used in a biotin-streptavidin-alkaline phosphatase complex immunohistochemical method on sections of formalin-and ethanol-fixed tissue specimens. Macrophages in inflamed areas of the lung (8/12), in the brain (5/16), and in the spinal cord (4/16) from encephalitic animals harbored viral antigens, as revealed by immunohistochemistry and use of a capsid protein-specific antiserum. Altogether 12/16 encephalitic animals tested positive for viral antigen. Viral antigens were found in 5/10 seropositive asymptomatic goats in macrophages located in the lung (3), the udder (1), and the medulla of lymph nodes (4). None of the control animals tested positive for viral antigen. Ethanol fixation showed highest sensitivity, and the lowest antigen concentration that revealed a positive signal discernible from background was twofold higher in ethanol-fixed specimens than in formalin-fixed specimens. The evaluation was performed on artificial antigen substrates embedded with defined concentrations of recombinant viral capsid protein. Immunohistochemistry is a valuable supplement to the methods presently available for diagnosis in cases suspicious of caprine arthritis-encephalitis.
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O'REILLY, DAVID R., ALLAN M. CRAWFORD et LOIS K. MILLER. « Viral proliferating cell nuclear antigen ». Nature 337, no 6208 (février 1989) : 606. http://dx.doi.org/10.1038/337606a0.

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Woodland, David L. « Viral Inhibition of Antigen Presentation ». Viral Immunology 29, no 7 (septembre 2016) : 377–78. http://dx.doi.org/10.1089/vim.2016.29011.dlw.

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Miller, Daniel M., et Daniel D. Sedmak. « Viral effects on antigen processing ». Current Opinion in Immunology 11, no 1 (février 1999) : 94–99. http://dx.doi.org/10.1016/s0952-7915(99)80017-x.

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Yewdell, Jonathan W., et Ann B. Hill. « Viral interference with antigen presentation ». Nature Immunology 3, no 11 (novembre 2002) : 1019–25. http://dx.doi.org/10.1038/ni1102-1019.

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Thèses sur le sujet "Viral antigen"

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Clayton, Anne-Louise. « Immunoassays for viral antigen detection in clinical specimens ». Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254677.

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Kučinskaitė-, Kodzė Indrė. « Production, Characterization And Application Of New Monoclonal Antibodies Against Viral Antigens ». Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110630_104940-67693.

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The dissertation describes development and characterization of monoclonal antibodies against recombinant yeast-expressed antigens: nucleocapsid (N) proteins of human parainfluenza virus type 3, Menangle virus, hantavirus and rabies virus. The newly developed antibodies were investigated by different immunochemical assays for their specificity, affinity and ability to recognize native viruses in infected cells. It was determined that the antibodies raised against recombinant yeast-expressed viral proteins are suitable to identify virusinfected cells. These data confirmed that recombinant yeast-expressed viral N proteins possess antigenic properties similar to that of native viral nucleocapsids. The monoclonal antibodies were also used to study the antigenic structure of viral N proteins and localize their immunodominant regions. The obtained results may have impact on the development of new immunodiagnostic test systems for the detection of viral infections. The dissertation consists of the introduction, three sections, references, and the list of author’s publications. In the Introductory Chapter, the research topic, the actuality, the aim and tasks, scientific novelty and practical value of the dissertation are discussed. Author’s publications and conference reports are also presented. The first Chapter of the dissertation provides literature overview on the genome organization, structural proteins, pathogenesis and epidemiology of parainfluenza viruses, Menangle virus... [to full text]
Disertacijoje aprašomi monokloniniai antikūnai, sukurti prieš rekombinantinius mielėse susintetintus antigenus: žmogaus paragripo treciojo tipo viruso, Menangle viruso, hantavirusų bei pasiutligės viruso nukleokapsidės (N) baltymus. Sukurtieji antikūnai buvo visapusiškai charakterizuoti įvairiais imunocheminės analizės metodais, įvertintas jų specifiškumas, afiniškumas, sugebėjimas atpažinti natyvius virusus infekuotų ląstelių kultūrose. Buvo nustatyta, kad antikūnai, sukurti prieš rekombinantinius mielėse susintetintus virusų baltymus, tinka virusų nustatymui infekuotose ląstelėse. Šie tyrimai patvirtino, kad rekombinantiniai mielėse susintetinti virusu N baltymai turi panašias antigenines savybes, kaip natyvūs virusų N baltymai, formuojantys nukleokapsides. Sukurtieji monokloniniai antikūnai taip pat buvo panaudoti išsamiems minėtų virusų N baltymų antigeninės struktūros tyrimams bei imunodominuojančių sekų nustatymui. Disertaciniame darbe gauti duomenys svarbūs, kuriant naujas imunodiagnostikos sistemas, skirtas virusų infekcijoms nustatyti. Disertacija sudaro įvadas, trys skyriai, naudotos literatūros sąrašas ir autorės publikacijų sąrašas. Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, formuluojamas darbo tikslas bei uždaviniai, darbo mokslinis naujumas ir praktinė reikšmė, pristatomos paskelbtos publikacijos ir pranešimai konferencijose. Pirmasis disertacijos skyrius skirtas literatūros apžvalgai: jame apibūdinamos paragripo virusų, Menangle viruso... [toliau žr. visą tekstą]
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Nastke, Maria-Dorothea. « T-cell epitopes from viral and tumor associated antigens induction and analysis of antigen-specific T cells / ». [S.l. : s.n.], 2005. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB12168223.

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Chen, Yun-Chi. « Control of immune response and pathogenesis by antigen during viral infection ». Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413974.

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Glew, Elizabeth Jane. « The interaction of bovine viral diarrhoea virus with antigen presenting cells ». Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312578.

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Biswas, Sumi. « Prime boost vaccination with viral vectors targeting apical membrane antigen 1 ». Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:a17ab4e4-9b81-4ab3-b02f-41d9da36c6ab.

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Apical membrane antigen 1 (AMA1) is a leading candidate vaccine antigen against blood stage malaria and several clinical trials using mostly protein-in-adjuvant vaccines have shown limited success. This thesis describes the development of recombinant adenoviral (AdHu5) and poxviral (MVA) vectors encoding AMA1 from Plasmodium chabaudi murine parasites. In this murine malaria model, AdHu5 and MVA encoding AMA1 when used in a heterologous prime boost regime showed excellent immunogenicity, both humoral and cellular. The vaccination regime was protective against blood stage challenge and both antibodies and CD4+ T cells found to be important for vaccine induced blood stage protection. In parallel to this novel P. falciparum vaccines encoding AMA1 were also developed and administered in a similar prime boost regime to mice and rabbits. The vaccination regime induced cellular immune response and high titre antibodies against AMA1 and these antibodies showed growth inhibitory activity against the homologous parasite strain. In an effort to overcome the issue of antigenic polymorphism and to circumvent pre-existing immunity to human adenovirus, biallelic simian and human adenoviral vectors and MVA encoding AMA1 vaccines were also developed and administered to mice and macaques. These vectors also induced high titre antibodies and the serum from macaques was found to have growth inhibitory activity. These vaccine candidates are now being taken forward to Phase I/II clinical trials in Oxford. This work also described the attempt to improve MVA as a antibody inducing vector to allow better antibody mediated immunity to blood stage malaria.
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Wong, Hiu-ling Beatrice. « Development of antibody and antigen detection assays and vaccines for SARS associated coronavirus ». Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39634024.

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Wong, Hiu-ling Beatrice, et 黃曉靈. « Development of antibody and antigen detection assays and vaccines for SARS associated coronavirus ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39634024.

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Bhati, Anubhuti. « EXPRESSION OF HEPATITIS C VIRAL NON-STRUCTURAL 3 ANTIGEN IN TRANSGENIC CHLOROPLASTS ». Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3076.

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Hepatitis C viral infection is the major cause of acute hepatitis and chronic liver disease and remains the leading cause of liver transplants (NIH). An estimated 180 million people are infected globally (WHO). There is no vaccine available to prevent hepatitis C. The treatment with antiviral drugs is expensive, accompanied with various side effects and is limited only to those at risk of developing advanced liver disease. The treatment is also effective in only about 30% to 50% of treated patients and still a high percentage of patients are resistant to therapy. Therefore, there is an urgent need for the development of effective vaccine antigens and an efficacious HCV vaccine. The non-structural 3 protein of the hepatitis C virus is a multifunctional protein of the virus required for virus polyprotein processing and replication. Vaccine antigen production via chloroplast transformation system usually results in high expression levels and eliminates the possibility of contamination with vector sequences,human or animal pathogens. The HCV NS3 antigen was expressed in the chloroplast of Nicotiana tabacum var. Petit havana and LAMD-609. The 1.9kb NS3 gene was cloned into a chloroplast expression vector, pLD-Ct containing the 16S rRNA promoter, aadA gene coding for the spectinomycin selectable marker, psbA 5' untranslated region to enhance translation in the light and 3' untranslated region for transcript stability and trnI & trnA homologous flanking sequences for site specific integration into the chloroplast genome. Chloroplast integration of the NS3 gene was first confirmed by PCR. Southern blot analysis further confirmed site-specific gene integration and homoplasmy. The NS3 protein was detected in transgenic chloroplasts by immunoblot analysis. The NS3 protein was further quantified by ELISA. Maximum expression levels of NS3 up to 2% in the total soluble protein were observed even in old leaves, upon 3-day continuous illumination. These results demonstrate successful expression of the HCV non-structural 3 antigen in transgenic tobacco chloroplasts. Animal studies to test the immunogenecity of the chloroplast derived HCV NS3 will be performed using chloroplast derived NS3 antigen.
M.S.
Department of Molecular Biology and Microbiology
Burnett College of Biomedical Sciences
Molecular Biology and Microbiology
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Lee, Sang-Ryul. « Bovine viral diarrhea virus infections affect professional antigen presentation in bovine monocytes ». Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-10222007-092315.

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Livres sur le sujet "Viral antigen"

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1929-, Laver William Graeme, Air Gillian et Cold Spring Harbor Laboratory, dir. Immune recognition of protein antigens. Cold Spring Harbor, N.Y : Cold Spring Harbor Laboratory, 1985.

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Pollwein, Peter. Spezifische Bindungsstellen von SV40 T-Antigen im zellulären Mausgenom. Konstanz : Hartung-Gorre, 1987.

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1941-, Thomas D. Brian, dir. Viruses and the cellular immune response. New York : Marcel Dekker, 1993.

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Kyuhei, Tomonari, dir. Viral superantigens. Boca Raton : CRC Press, 1997.

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Kang, Chʻang-yul. Pairŏsŭ pektʻŏ ro hyŏngjil toiptoen hangwŏn chesi sepʻo ŭi myŏnyŏk chʻiryoje yuhyosŏng pʻyŏngka mit sihŏmpŏp yŏnʼgu = : Development and estimation of immunotherapeutic cell-based vaccine approaches using antigen presenting cells transduced with viral vector. [Seoul] : Sikpʻum Ŭiyakpʻum Anjŏnchʻŏng, 2007.

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R, Burton Dennis, dir. Antibodies in viral infection. Berlin : Springer, 2001.

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International Symposium on the Immunobiology of Proteins and Peptides (3rd 1984 Tahoe City, Calif.). Immunobiology of proteins and peptides III : Viral and bacterial antigens. New York : Plenum Press, 1985.

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V, Quinnan Gerald, dir. Vaccinia viruses as vectors for vaccine antigens : Proceedings of the Workshop on Vaccinia Viruses as Vectors for Vaccine Antigens, held November 13-14, 1984, in Chevy Chase, Maryland, U.S.A. New York : Elsevier, 1985.

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1937-, Cruse Julius M., et Lewis R. E. 1947-, dir. Antigenic variation : Molecular and genetic mechanisms of relapsing disease. Basel : Karger, 1987.

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T, Huber Brigitte, et Palmer Ed 1952-, dir. Superantigens : A pathogen's view of the immune system. Plainview, N.Y : Cold Spring Harbor Laboratory Press, 1993.

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Chapitres de livres sur le sujet "Viral antigen"

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Leland, Diane S., et Ryan F. Relich. « Viral Antigen Detection ». Dans Clinical Virology Manual, 95–104. Washington, DC, USA : ASM Press, 2016. http://dx.doi.org/10.1128/9781555819156.ch8.

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Jazayeri, Seyed Mohammad, Seyed Moayed Alavian, Payam Dindoost, Howard C. Thomas et Peter Karayiannis. « Molecular Variants of Hepatitis B Surface Antigen (HBsAg) ». Dans Viral Hepatitis, 107–26. Oxford, UK : John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118637272.ch8.

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Tevethia, Satvir S. « Heterogeneity of CTL Reactive Antigenic Sites on SV40 Tumor Antigen ». Dans Concepts in Viral Pathogenesis II, 182–86. New York, NY : Springer New York, 1986. http://dx.doi.org/10.1007/978-1-4612-4958-0_21.

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Whitton, J. Lindsay, et Michael B. A. Oldstone. « Antigen Recognition by Cytotoxic T Cells ». Dans Concepts in Viral Pathogenesis III, 130–36. New York, NY : Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4613-8890-6_15.

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Krawczynski, K. « Identification of HCV-associated antigen(s) in hepatocytes ». Dans Chronically Evolving Viral Hepatitis, 196–98. Vienna : Springer Vienna, 1992. http://dx.doi.org/10.1007/978-3-7091-5633-9_41.

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Petre, J., T. Rutgers et P. Hauser. « Properties of a recombinant yeast-derived hepatitis B surface antigen containing S, preS2 and preSl antigenic domains ». Dans Chronically Evolving Viral Hepatitis, 137–41. Vienna : Springer Vienna, 1992. http://dx.doi.org/10.1007/978-3-7091-5633-9_30.

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Praest, Patrique, Hendrik de Buhr et Emmanuel J. H. J. Wiertz. « A Flow Cytometry-Based Approach to Unravel Viral Interference with the MHC Class I Antigen Processing and Presentation Pathway ». Dans Antigen Processing, 187–98. New York, NY : Springer New York, 2019. http://dx.doi.org/10.1007/978-1-4939-9450-2_14.

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Horst, Daniëlle, Maaike E. Ressing, Arend Mulder et Emmanuel J. H. J. Wiertz. « Evaluation of Viral Interference with MHC Class I-Restricted Antigen Processing and Presentation Using a Flow Cytometry-Based Approach ». Dans Antigen Processing, 127–36. Totowa, NJ : Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-218-6_10.

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Schmid, Dorothee, et Christian Münz. « Endogenous Major Histocompatibility Complex Class II Antigen Processing of Viral Antigens ». Dans Autophagy in Immunity and Infection, 212–25. Weinheim, FRG : Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/352760880x.ch12.

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Ferrari, C., Amalia Penna, A. Bertoletti et F. Fiaccadori. « Cell mediated immune response to hepatitis B virus nucleocapsid antigen ». Dans Research in Chronic Viral Hepatitis, 91–101. Vienna : Springer Vienna, 1993. http://dx.doi.org/10.1007/978-3-7091-9312-9_10.

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Actes de conférences sur le sujet "Viral antigen"

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Reuter, Sebastian, Nina Dehzad, Helen Martin, Matthias Jung, Anke Heinz, Michael Stassen, Roland Buhl et Christian Taube. « Viral Components Enhance Antigen Presentation And Induce Sensitization Towards Harmless Inhaled Antigens ». Dans American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a5631.

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Jain, Akshat, et Shamik Tiwari. « Prediction and Visualisation of Viral Genome Antigen Using Deep Learning & ; Artificial Intelligence ». Dans 2021 5th International Conference on Computing Methodologies and Communication (ICCMC). IEEE, 2021. http://dx.doi.org/10.1109/iccmc51019.2021.9418356.

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Scott, Gregory D., David B. Jacoby et Allison D. Fryer. « Changes In Sensory Innervation Of The Airways After Antigen Challenge And Viral Infection ». Dans American Thoracic Society 2010 International Conference, May 14-19, 2010 • New Orleans. American Thoracic Society, 2010. http://dx.doi.org/10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a5543.

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Ramona, Stoicescu, Stoicescu Razvan-Alexandru, Codrin Gheorghe et Schroder Verginica. « LABORATORY METHODS AND PREVALENCE OF SARS-COV-2 INFECTIONS IN THE 2ND SEMESTER OF 2021 IN THE EMERGENCY CLINICAL COUNTY HOSPITAL OF CONSTANTA ». Dans GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/11.

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"Diagnosing infections with SARS-CoV-2 is still of great interest due to the health and economic impact of COVID pandemic. The 4th wave of the COVID-19 pandemic is expected and is considered to be stronger and faster due to the dominance of Delta variant which is highly contagious [1]. SARS-CoV-2 also known as 2019-nCoV is one of the three coronaviruses (together with SARS-CoV or SARS-CoV1/Severe acute respiratory syndrome coronavirus), MERS-CoV /Middle East Respiratory Syndrome coronavirus) which can cause severe respiratory tract infections in humans [2]. Early diagnosis in COVID 19 infection is the key for preventing infection transmission in collectivity and proper medical care for the ill patients. Gold standard for diagnosing SARS-Co-V-2 infection according to WHO recommendation is using nucleic acid amplification tests (NAAT)/ reverse transcription polymerase chain reaction (RT-PCR). The search is on to develop reliable but less expensive and faster diagnostic tests that detect antigens specific for SARS-CoV-2 infection. Antigen-detection diagnostic tests are designed to directly detect SARSCoV-2 proteins produced by replicating virus in respiratory secretions so-called rapid diagnostic tests, or RDTs. The diagnostic development landscape is dynamic, with nearly a hundred companies developing or manufacturing rapid tests for SARS-CoV-2 antigen detection [3]. In the last 3 months our hospital introduced the antigen test or Rapid diagnostic tests (RDT) which detects the presence of viral proteins (antigens) expressed by the COVID-19 virus in a sample from the respiratory tract of a person. All RDT were confirmed next day with a RT-PCR. The number of positive cases detected during 3 months in our laboratory was 425. There were 326 positive tests in April, 106 positive tests in May and 7 positive tests in June. Compared with the number of positive tests in the 1st semester of 2021, the positive tests have significantly declined."
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Lewis, R. M., P. B. Jahrling, B. P. Griffin et T. M. Cosgriff. « THE EFFECTS OF HEMORRHAGIC FEVER VIRUS INFECTION OF ENDOTHELIAL CELLS ». Dans XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643352.

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Pichindé viral infection of strain 13 guinea pigs is a model for Lassa fever virus in humans. Infected animals show impaired platelet function and altered coagulation parameters. Human endothelial cells and the human endothe1ia1-1 ike cell line, EA926, were infected with Pichinde virus. Following infection, cultures were monitored by phase contract microscopy for cytopathic effect (CPE). Assays of supernatant were used to document viral growth and to measure those endothelial-produced components that might affect hemostasis. In addition, the cells were stimulated with phorbol ester (PMA), which stimulates the production of prostacyclin. Infection showed no noticeable effect on the endothelial cells or EA926 cells which were untreated with PMA. PHA-treated EA926 cells were subject to CPE. Factor VIII antigen was not significantly affected by viral infection, PMA treatment, or endotoxin exposure. The production of PGFl, measured as an estimate of prostacyclin synthesis, was dependent on the concentration of stimulating PMA. Infected cultures showed decreased responsiveness to PMA stimulation when infected by increasing concentrations of Pichindé. The most noticeable effect was noted when cultures were infected with a multiplicity of infection of 0.1 and 100 ng/ml PMA. Thromboxane B2 an estimate of thromboxane A2, showed no significant change. No detectable leukotriene C4 was produced and no significant change in leukotriene B4 was measured. The decreased prostacyclin production by the infected endothelial cells may indicate a role for the endothelium in the hemorrhagic syndrome that accompanies some viral diseases.
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Wernet, P., E. M. Scheider, P. Sarin, P. Chandra, H. H. Brackmann, M. Kessler et H. Egli. « Demonstration of HIV-encoded Proteins in Cultured and in Uncultured CD 4 Positive Mononuclear Cells from Hemophilia Patients Employing Monoclonal Antibodies against p 15, p 24, GP 41, GP 120, and Reverse Transcriptase ». Dans XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644683.

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In the light of the large percentage of hemophilia patients with antibodies to HIV the identification of a specific virus infection in comparison to HIV antibody negative hemophilia patients has reached crucial importance. The low success rates of direct virus culture techniques together with the as yet low AIDS-di-sease rate observed in these patients separate these patients from the other main risk groups. Within this context, we studied the expression of CD3, CD4, CD8, and HLA class II antigens on fixed cells after PHA stimulation and Interleukin 2 propagation as well as on untreated blood mononuclear cells from healthy individuals and from hemophilia patients by fluorescence activated flow cytometry. Monoclonal antibodies thought to be specific for p 15, p 24, GP 41, GP 120, and for reverse transcriptase revealed a certain number of positive cells on all defined subpopulations analysed. From cell specimen of HIV antibody positive hemophilia patients cells with specific HIV antigens could be enriched by in vitro cultivation. Importantly the expression of virus-encoded antigens preceedes a cytopathic effect for several daVs. Current analyses aim at the prognostic relevance of low amounts of such viral HIV proteins selectively detectable by moAbs.directed to either p 24, GP 41, GP 120, and RT. The reliability, high sensitivity and monoclonal antibody dependent specificity of this newly developed method for the demonstration of HIV specific proteins make it applicable also for longitudinal surveys of hemophilia patients to assess a potential state of viremia or virus antigen processing in their mononuclear cells.
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Chicaybam, Leonardo, Mayra Carneiro, Bárbara Peixoto, Luiza Abdo, Luciana Carvalho et Martín Bonamino. « Production of chimeric antigen receptor (CAR)-T cells for preclinical testing using non-viral transposon vectors and a lymphoblastoid cell line (LCL) ». Dans VI Seminário Anual Científico e Tecnológico. Instituto de Tecnologia em Imunobiológicos, 2018. http://dx.doi.org/10.35259/isi.sact.2018_27282.

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Bajaj, Anshika, Lisa Y. Ngo, Peter Berglund et Jan ter Meulen. « Abstract 5092 : ZVex® lentiviral vector strongly activates pro-inflammatory, antigen processing, and anti-viral defense response pathways in monocyte-derived dendritic cells ». Dans Proceedings : AACR Annual Meeting 2017 ; April 1-5, 2017 ; Washington, DC. American Association for Cancer Research, 2017. http://dx.doi.org/10.1158/1538-7445.am2017-5092.

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Wang, Chuan, Yidao Wang, Alex J. Allen, Jantipa Jobsri, Gareth J. Thomas, Christian H. Ottensmeier et Natalia Savelyeva. « Abstract B139 : Plant viral particle vaccine induces a potent antitumor response through induction of antigen-specific T-cells and overcoming an immunosuppressive tumor microenvironment ». Dans Abstracts : Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference : Translating Science into Survival ; September 30 - October 3, 2018 ; New York, NY. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/2326-6074.cricimteatiaacr18-b139.

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Shaheen, S., H. Akita, I. Souichirou, N. Miura et H. Harashima. « Abstract P4-04-08 : A Potential non-viral vector to transfect dendritic cell and thereby MHC-Class I antigen presentation might be a potential use in carcinoma ». Dans Abstracts : Thirty-Fifth Annual CTRC‐AACR San Antonio Breast Cancer Symposium‐‐ Dec 4‐8, 2012 ; San Antonio, TX. American Association for Cancer Research, 2012. http://dx.doi.org/10.1158/0008-5472.sabcs12-p4-04-08.

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Rapports d'organisations sur le sujet "Viral antigen"

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Vakharia, Vikram, Shoshana Arad, Yonathan Zohar, Yacob Weinstein, Shamila Yusuff et Arun Ammayappan. Development of Fish Edible Vaccines on the Yeast and Redmicroalgae Platforms. United States Department of Agriculture, février 2013. http://dx.doi.org/10.32747/2013.7699839.bard.

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Betanodaviruses are causative agents of viral nervous necrosis (VNN), a devastating disease of cultured marine fish worldwide. Betanodavirus (BTN) genome is composed of two single-stranded, positive-sense RNA molecules. The larger genomic segment, RNA1 (3.1 kb), encodes the RNA-dependent RNA polymerase, while the smaller genomic segment, RNA 2 (1.4kb), encodes the coat protein. This structural protein is the host-protective antigen of VNN which assembles to form virus-like particles (VLPs). BTNs are classified into four genotypes, designated red-spotted grouper nervous necrosis virus (RGNNV), barfin flounder nervous necrosis virus (BFNNV), tiger puffer nervous necrosis virus (TPNNV), and striped jack nervous necrosis virus (SJNNV), based on phylogenetic analysis of the coat protein sequences. RGNNV type is quite important as it has a broad host-range, infecting warm-water fish species. At present, there is no commercial vaccine available to prevent VNN in fish. The general goal of this research was to develop oral fish vaccines in yeast and red microalgae (Porphyridium sp.) against the RGNNV genotype. To achieve this, we planned to clone and sequence the coat protein gene of RGNNV, express the coat protein gene of RGNNV in yeast and red microalgae and evaluate the immune response in fish fed with recombinantVLPs antigens produced in yeast and algae. The collaboration between the Israeli group and the US group, having wide experience in red microalgae biochemistry, molecular genetics and large-scale cultivation, and the development of viral vaccines and eukaryotic protein expression systems, respectively, was synergistic to produce a vaccine for fish that would be cost-effective and efficacious against the betanodavirus infection.
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Gershoni, Jonathan M., David E. Swayne, Tal Pupko, Shimon Perk, Alexander Panshin, Avishai Lublin et Natalia Golander. Discovery and reconstitution of cross-reactive vaccine targets for H5 and H9 avian influenza. United States Department of Agriculture, janvier 2015. http://dx.doi.org/10.32747/2015.7699854.bard.

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Research objectives: Identification of highly conserved B-cell epitopes common to either H5 or H9 subtypes of AI Reconstruction of conserved epitopes from (1) as recombinantimmunogens, and testing their suitability to be used as universal vaccine components by measuring their binding to Influenza vaccinated sera of birds Vaccination of chickens with reconstituted epitopes and evaluation of successful vaccination, clinical protection and viral replication Development of a platform to investigate the dynamics of immune response towards infection or an epitope based vaccine Estimate our ability to focus the immune response towards an epitope-based vaccine using the tool we have developed in (D) Summary: This study is a multi-disciplinary study of four-way collaboration; The SERPL, USDA, Kimron-Israel, and two groups at TAU with the purpose of evaluating the production and implementation of epitope based vaccines against avian influenza (AI). Systematic analysis of the influenza viral spike led to the production of a highly conserved epitope situated at the hinge of the HA antigen designated “cluster 300” (c300). This epitope consists of a total of 31 residues and was initially expressed as a fusion protein of the Protein 8 major protein of the bacteriophagefd. Two versions of the c300 were produced to correspond to the H5 and H9 antigens respectively as well as scrambled versions that were identical with regard to amino acid composition yet with varied linear sequence (these served as negative controls). The recombinantimmunogens were produced first as phage fusions and then subsequently as fusions with maltose binding protein (MBP) or glutathioneS-transferase (GST). The latter were used to immunize and boost chickens at SERPL and Kimron. Furthermore, vaccinated and control chickens were challenged with concordant influenza strains at Kimron and SEPRL. Polyclonal sera were obtained for further analyses at TAU and computational bioinformatics analyses in collaboration with Prof. Pupko. Moreover, the degree of protection afforded by the vaccination was determined. Unfortunately, no protection could be demonstrated. In parallel to the main theme of the study, the TAU team (Gershoni and Pupko) designed and developed a novel methodology for the systematic analysis of the antibody composition of polyclonal sera (Deep Panning) which is essential for the analyses of the humoral response towards vaccination and challenge. Deep Panning is currently being used to monitor the polyclonal sera derived from the vaccination studies conducted at the SEPRL and Kimron.
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Kotler, Moshe, Larry Hanson et Shane Burgess. Replication Defective Cyprinid Herpes Virus-3 (CyHV-3) as a Combined Prophylactic Vaccine in Carps. United States Department of Agriculture, décembre 2010. http://dx.doi.org/10.32747/2010.7697104.bard.

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Aquacultured koi and common carp fish (Cyprinus carpio) are intensively bred as ornamental and food fish in many countries worldwide. Hatcheries of carp and koi have recently suffered massive financial damages due to two viral diseases caused by the Cyprinid herpesvirus-3 (CyHV-3), previously designated as Carp Interstitial Nephritis and Gill Necrosis Virus (CNGV) and Koi herpesvirus (KHV), and by the Spring Viremia of Carp Virus (SVCV). CyHV-3 is a large dsDNA virus, which is infectious mostly to koi and common carp, while SVCV is a rhabdovirus with a relatively broad host range. Both viruses induce contagious disease with mortality rate up to 90%. Strategies for the control of viral infection in fish are of limited use. While efforts to prevent introduction of infectious agents into culture facilities are desirable, such exclusion strategies are far from fail-safe. Extensive vaccination methods that are useful for use in aquaculture facilities produce weak immunity, when used with proteins or inactivated viruses. Methods to overcome this obstacle are to vaccinate the fish with large amounts of antigen and/or use adjuvant and immune modulators over a long period. These techniques usually require individual handling of the fish. On the other hand, live attenuated virus is efficient and economical when used as an immersionvaccine. However, this technique poses certain environmental risks and thus may be difficult to license and scale up. Another option is a vaccine based on the replication defective virus (RDV) (pseudovirus), which can infect cells, but is unable to produce infectious particles. This vaccine may circumvent many of the problems related to attenuated-live vaccine (e.g., inadvertent infection and reversion to the virulent strain).
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Malkinson, Mertyn, Irit Davidson, Moshe Kotler et Richard L. Witter. Epidemiology of Avian Leukosis Virus-subtype J Infection in Broiler Breeder Flocks of Poultry and its Eradication from Pedigree Breeding Stock. United States Department of Agriculture, mars 2003. http://dx.doi.org/10.32747/2003.7586459.bard.

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Objectives 1. Establish diagnostic procedures to identify tolerant carrier birds based on a) Isolation of ALV-J from blood, b) Detection of group-specific antigen in cloacal swabs and egg albumen. Application of these procedures to broiler breeder flocks with the purpose of removing virus positive birds from the breeding program. 2. Survey the AL V-J infection status of foundation lines to estimate the feasibility of the eradication program 3. Investigate virus transmission through the embryonated egg (vertical) and between chicks in the early post-hatch period (horizontal). Establish a model for limiting horizontal spread by analyzing parameters operative in the hatchery and brooder house. 4. Compare the pathogenicity of AL V-J isolates for broiler chickens. 5. Determine whether AL V-J poses a human health hazard by examining its replication in mammalian and human cells. Revisions. The: eradication objective had to be terminated in the second year following the closing down of the Poultry Breeders Union (PBU) in Israel. This meant that their foundation flocks ceased to be available for selection. Instead, the following topics were investigated: a) Comparison of commercial breeding flocks with and without myeloid leukosis (matched controls) for viremia and serum antibody levels. b) Pathogenicity of Israeli isolates for turkey poults. c) Improvement of a diagnostic ELISA kit for measuring ALV-J antibodies Background. ALV-J, a novel subgroup of the avian leukosis virus family, was first isolated in 1988 from broiler breeders presenting myeloid leukosis (ML). The extent of its spread among commercial breeding flocks was not appreciated until the disease appeared in the USA in 1994 when it affected several major breeding companies almost simultaneously. In Israel, ML was diagnosed in 1996 and was traced to grandparent flocks imported in 1994-5, and by 1997-8, ML was present in one third of the commercial breeding flocks It was then realized that ALV-J transmission was following a similar pattern to that of other exogenous ALVs but because of its unusual genetic composition, the virus was able to establish an extended tolerant state in infected birds. Although losses from ML in affected flocks were somewhat higher than normal, both immunosuppression and depressed growth rates were encountered in affected broiler flocks and affected their profitability. Conclusions. As a result of the contraction in the number of international primary broiler breeders and exchange of male and female lines among them, ALV-J contamination of broiler breeder flocks affected the broiler industry worldwide within a short time span. The Israeli national breeding company (PBU) played out this scenario and presented us with an opportunity to apply existing information to contain the virus. This BARD project, based on the Israeli experience and with the aid of the ADOL collaborative effort, has managed to offer solutions for identifying and eliminating infected birds based on exhaustive virological and serological tests. The analysis of factors that determine the efficiency of horizontal transmission of virus in the hatchery resulted in the workable solution of raising young chicks in small groups through the brooder period. These results were made available to primary breeders as a strategy for reducing viral transmission. Based on phylogenetic analysis of selected Israeli ALV-J isolates, these could be divided into two groups that reflected the countries of origin of the grandparent stock. Implications. The availability of a simple and reliable means of screening day old chicks for vertical transmission is highly desirable in countries that rely on imported breeding stock for their broiler industry. The possibility that AL V-J may be transmitted to human consumers of broiler meat was discounted experimentally.
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Mawassi, Munir, Adib Rowhani, Deborah A. Golino, Avichai Perl et Edna Tanne. Rugose Wood Disease of Grapevine, Etiology and Virus Resistance in Transgenic Vines. United States Department of Agriculture, novembre 2003. http://dx.doi.org/10.32747/2003.7586477.bard.

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Rugose wood is a complex disease of grapevines, which occurs in all growing areas. The disease is spread in the field by vector transmission (mealybugs). At least five elongated-phloem- limited viruses are implicated in the various rugose wood disorders. The most fully characterized of these are Grapevine virus A (GV A) and GVB, members of a newly established genus, the vitivirus. GVC, a putative vitivirus, is much less well characterized than GV A or GVB. The information regarding the role of GVC in the etiology and epidemiology of rugose wood is fragmentary and no sequence data for GVC are available. The proposed research is aimed to study the etiology and epidemiology of rugose wood disease, and to construct genetically engineered virus-resistant grapevines. The objectives of our proposed research were to construct transgenic plants with coat protein gene sequences designed to induce post-transcriptional gene silencing (pTGS); to study the epidemiology and etiology of rugose wood disease by cloning and sequencing of GVC; and surveying of rugose wood- associated viruses in Californian and Israeli vineyards. In an attempt to experimentally define the role of the various genes of GV A, we utilized the infectious clone, inserted mutations in every ORF, and studied the effect on viral replication, gene expression, symptoms and viral movement. We explored the production of viral RNAs in a GV A-infected Nicotiana benthamiana herbaceous host, and characterized one nested set of three 5'-terminal sgRNAs of 5.1, 5.5 and 6.0 kb, and another, of three 3'-terminal sgRNAs of 2.2, 1.8 and 1.0 kb that could serve for expression of ORFs 2-3, respectively. Several GV A constructs have been assembled into pCAMBIA 230 I, a binary vector which is used for Angrobacterium mediated transformation: GV A CP gene; two copies of the GV A CP gene arranged in the same antisense orientation; two copies of the GV A CP gene in which the downstream copy is in an antigens orientation; GV A replicase gene; GV A replicase gene plus the 3' UTR sequence; and the full genome of GV A. Experiments for transformation of N. benthamiana and grapevine cell suspension with these constructs have been initiated. Transgenic N. benthamiana plants that contained the CP gene, the replicase gene and the entire genome of GV A were obtained. For grapevine transformation, we have developed efficient protocols for transformation and successfully grapevine plantlets that contained the CP gene and the replicase genes of GV A were obtained. These plants are still under examination for expression of the trans genes. The construction of transgenic plants with GV A sequences will provide, in the long run, a means to control one of the most prevalent viruses associated with grapevines. Our many attempts to produce a cDNA library from the genome of GVC failed. For surveying of rugose wood associated viruses in California vineyards, samples were collected from different grape growing areas and tested by RT-PCR for GV A, GVB and GVD. The results indicated that some of the samples were infected with multiple viruses, but overall, we found higher incidence of GVB and GV A infection in California vineyards and new introduction varieties, respectively. In this research we also conducted studies to increase our understanding of virus - induced rootstock decline and its importance in vineyard productivity. Our results provided supporting evidence that the rootstock response to virus infection depends on the rootstock genotype and the virus type. In general, rootstocks are differ widely in virus susceptibility. Our data indicated that a virus type or its combination with other viruses was responsible in virus-induced rootstock decline. As the results showed, the growth of the rootstocks were severely affected when the combination of more than one virus was present.
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Dolja, Valerian V., Amit Gal-On et Victor Gaba. Suppression of Potyvirus Infection by a Closterovirus Protein. United States Department of Agriculture, mars 2002. http://dx.doi.org/10.32747/2002.7580682.bard.

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The plant virus family Polyviridae is the largest and most destructive of all plant viruses. Despite the continuous effort to develop resistant plant varieties, there is a desperate need for novel approaches conferring wide-range potyvirus resistance. Based on experiments with the tobacco etch potyvirus (TEV)-derived gene expression vector, we suggested approach for screening of the candidate resistance genes. This approach relies on insertion of the genes into a virus vector and evaluation of the phenotypes of the resulting recombinant viruses. The genes which suppress infection by the recombinant virus are selected as candidates for engineering transgenic resistance. Our analysis of the TEV variants expressing proteins of the beet yellows closterovirus (BYV) revealed that one of those, the leader proteinase (L-Pro), strongly and specifically interfered with the hybrid TEV infection. Since closterovirus L-Pro is evolutionary related to potyviral helper component-proteinase (HC-Pro), we suggested that the L-Pro interfered with HC-Pro function via a trans-dominant inhibitory effect. Based on these findings, we proposed to test two major hypotheses. First, we suggested that L-Pro-mediated suppression of potyvirus infection is a general phenomenon effective against a range of potyviruses. The second hypothesis stated that the suppression effect can be reproduced in transgenic plants expressing L-Pro, and can be utilized for generation of resistance to potyviruses. In accord with these hypotheses, we developed two original objectives of our proposal: A) to determine the range of the closterovirus-derived suppression of potyviral infection, and B) to try and utilize the L-Pro-mediated suppression for the development of transgenic resistance to potyviruses. In the first phase of the project, we have developed all major tools and technologies required for successful completion of the proposed research. These included TEV and ZYMV vectors engineered to express several closteroviral L-Pro variants, and generation of the large collection of transgenic plants. To our satisfaction, characterization of the infection phenotypes exhibited by chimeric TEV and ZYMV variants confirmed our first hypothesis. For instance, similar to TEV-L- Pro(BYV) chimera, ZYMV-L-Pro(LIYV) chimera was debilitated in its systemic spread. In contrast, ZYMV-GUS chimera (positive control) was competent in establishing vigorous systemic infection. These and other results with chimeric viruses indicated that several closteroviral proteinases inhibit long-distance movement of the potyviruses upon co-expression in infected plants. In order to complete the second objective, we have generated ~90 tobacco lines transformed with closteroviral L-Pro variants, as well as ~100 lines transformed with BYV Hsp70-homolog (Hsp70h; a negative control). The presence and expression of the trans gene in each line was initially confirmed using RT-PCR and RNA preparations isolated from plants. However, since detection of the trans gene-specific RNA can not guarantee production of the corresponding protein, we have also generated L-Pro- and Hsp70h-specific antisera using corresponding synthetic peptides. These antisera allowed us to confirm that the transgenic plant lines produced detectable, although highly variable levels of the closterovirus antigens. In a final phase of the project, we tested susceptibility of the transgenic lines to TEV infection. To this end, we determined that the minimal dilution of the TEV inoculum that is still capable of infecting 100% of nontransgenic plants was 1:20, and used 10 plants per line (in total, ~2,000 plants). Unfortunately, none of the lines exhibited statistically significant reduction in susceptibility. Although discouraging, this outcome prompted us to expand our experimental plan and conduct additional experiments. Our aim was to test if closteroviral proteinases are capable of functioning in trans. We have developed agroinfection protocol for BYV, and tested if co- expression of the L-Pro is capable of rescuing corresponding null-mutant. The clear-cut, negative results of these experiments demonstrated that L-Pro acts only in cis, thus explaining the lack of resistance in our transgenic plants. We have also characterized a collection of the L-Pro alanine- scanning mutants and found direct genetic evidence of the requirement for L-Pro in virus systemic spread. To conclude, our research supported by BARD confirmed one but not another of our original hypotheses. Moreover, it provided an important insight into functional specialization of the viral proteinases and generated set of tools and data with which we will be able to address the molecular mechanisms by which these proteins provide a variety of critical functions during virus life cycle.
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