Visna Maedi Virus
Mostrando 25-36 de 48 artigos, teses e dissertações.
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25. Antigenic and Morphological Similarities of Progressive Pneumonia Virus, a Recently Isolated “Slow Virus” of Sheep, to Visna and Maedi Viruses
Progressive pneumonia virus, the causative agent of a slow, pulmonary disease of Montana sheep, was shown to be antigenically related to two other slow viruses of sheep, visna and maedi. Electron microscopic examination of infected cells revealed that the virus matures by a budding process and that the budding particles as well as the mature, extracellular v
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26. Evaluation of two recombinant Maedi-visna virus proteins for use in an enzyme-linked immunosorbent assay for the detection of serum antibodies to ovine lentiviruses.
Defined segments of the gag polyprotein and transmembrane envelope glycoprotein from Maedi-visna virus were expressed as glutathione S-transferase fusion proteins in Escherichia coli and evaluated singly and in combination for use in an enzyme-linked immunosorbent assay (ELISA). Two hundred sixty field serum specimens from 15 sheep flocks were tested in para
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27. Cytotoxic activity against maedi-visna virus-infected macrophages.
The cell type predominantly infected by maedi-visna virus (MVV) is the macrophage, and we have looked at the ability of MVV-infected macrophages to interact with cytotoxic T lymphocytes (CTL), important effector cells against virus infections. MVV-specific CTL precursors were detected, after in vitro culture with MVV antigen and recombinant human interleukin
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28. Properties of Wild-Type, C-Terminally Truncated, and Chimeric Maedi-Visna Virus Glycoprotein and Putative Pseudotyping of Retroviral Vector Particles
We have characterized the properties of the maedi-visna virus (MVV) glycoprotein, which has a long cytoplasmic C-terminal domain, and of a panel of C-terminally truncated and C-terminally chimeric MVV-Env constructs. Cells expressing wild-type MVV glycoprotein form syncytia with target cells from many different species and tissues, demonstrating that the MVV
American Society for Microbiology.
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29. Infection of Dendritic Cells by the Maedi-Visna Lentivirus
The early stages of lentivirus infection of dendritic cells have been studied in an in vivo model. Maedi-visna virus (MVV) is a natural pathogen of sheep with a tropism for macrophages, but the infection of dendritic cells has not been proven, largely because of the difficulties of definitively distinguishing the two cell types. Afferent lymphatic dendritic
American Society for Microbiology.
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30. Ultrastructural Studies of a Visna-Like Syncytia-Producing Virus from Cattle with Lymphocytosis
A virus structurally similar to viruses associated with maedi, progressive pneumonia, and visna of sheep has been isolated from buffy coat cells of cattle with chronic lymphocytosis. Electron microscope studies revealed three variants of the virion: (i) an intracytoplasmic form 98 to 116 nm in diameter when occurring in a nonlaminated form, (ii) a budding fo
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31. Morphological and immunological comparison of caprine arthritis encephalitis and ovine progressive pneumonia viruses.
Caprine arthritis encephalitis virus (CAEV) causes a variety of pathological conditions ranging from mild to very severe and from acute to chronic, depending upon the age of initial infection and other variables. Although the virus has been reported to have properties of characteristic of retroviruses and to be related to maedi-visna virus (also called progr
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32. Inhibition of visna virus replication by 2',3'-dideoxynucleosides and acyclic nucleoside phosphonate analogs.
A series of acyclic nucleoside phosphonate (ANP) and 2',3'-dideoxynucleoside (ddN) derivatives were evaluated for their inhibitory effects on visna virus replication and maedi/visna virus-induced syncytium formation in sheep choroid plexus cells. Most ANP derivatives inhibited virus replication and syncytium formation within a concentration range of 0.2 to 1
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33. Detection of antibodies to caprine arthritis-encephalitis virus by protein G enzyme-linked immunosorbent assay and immunoblotting.
Sera from goats suffering from caprine arthritis-encephalitis contained antibodies to virus proteins of 15, 17, 28, 40, and 130 kilodaltons in immunoblots of maedi-visna virus. We propose to use immunoblotting as a validation test for enzyme-linked immunosorbent assay and demonstrate that the specificity of indirect enzyme-linked immunosorbent assay can be i
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34. Highly lytic and persistent lentiviruses naturally present in sheep with progressive pneumonia are genetically distinct.
Ovine and caprine lentiviruses share the capacity to induce slowly progressive and inflammatory diseases of the central nervous system (leukoencephalitis or visna), lungs (progressive pneumonia or maedi), and joints (arthritis) in their natural hosts. Studies on their replication indicated that ovine lentiviruses and caprine arthritis-encephalitis virus (CAE
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35. Maedi-Visna Virus and Caprine Arthritis Encephalitis Virus Genomes Encode a Vpr-Like but No Tat Protein
A small open reading frame (ORF) in maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) was initially named “tat” by analogy with a similarly placed ORF in the primate lentiviruses. The encoded “Tat” protein was ascribed the function of up regulation of the viral transcription from the long terminal repeat (LTR) promoter, but we h
American Society for Microbiology.
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36. Lack of neutralizing antibodies to caprine arthritis-encephalitis lentivirus in persistently infected goats can be overcome by immunization with inactivated Mycobacterium tuberculosis.
The pathogenesis of the persistent progressive diseases of sheep (visna-maedi) and goats (arthritis-encephalitis) is dependent on continuous replication of the causative lentiviruses. One subgroup of these viruses, Icelandic visna virus, accomplishes this form of replication by undergoing antigenic mutation. Mutant viruses arising late in the infection escap