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Full-Text Articles in Virology

Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers Dec 1997

Direct Demonstration Of Retroviral Recombination In A Rhesus Monkey, Dawn P. Wooley, Randall A. Smith, Susan Czajak, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

Recombination may be an important mechanism for increasing variation in retroviral populations. Retroviral recombination has been demonstrated in tissue culture systems by artificially creating doubly infected cells. Evidence for retroviral recombination in vivo is indirect and is based principally on the identification of apparently mosaic human immunodeficiency virus type 1 genomes from phylogenetic analyses of viral sequences. We infected a rhesus monkey with two different molecularly cloned strains of simian immunodeficiency virus. One strain of virus had a deletion in vpx and vpr, and the other strain had a deletion in nef. Each strain on its own induced low virus …


Porcine Reproductive And Respiratory Syndrome Virus Replicates In Testicular Germ Cells, Alters Spermatogenesis, And Induces Germ Cell Death By Apoptosis, Jung-Hyang Sur, Alan R. Doster, James S. Christian, Judith A. Galeota, Robert W. Wills, Jeff J. Zimmerman, Fernando A. Osorio Dec 1997

Porcine Reproductive And Respiratory Syndrome Virus Replicates In Testicular Germ Cells, Alters Spermatogenesis, And Induces Germ Cell Death By Apoptosis, Jung-Hyang Sur, Alan R. Doster, James S. Christian, Judith A. Galeota, Robert W. Wills, Jeff J. Zimmerman, Fernando A. Osorio

Nebraska Center for Virology: Faculty Publications

Like other arteriviruses, porcine reproductive and respiratory syndrome virus (PRRSV) is shed in semen, a feature that is critical for the venereal transmission of this group of viruses. In spite of its epidemiological importance, little is known of the association of PRRSV or other arteriviruses with gonadal tissues. We experimentally infected a group of boars with PRRSV 12068-96, a virulent field strain. By combined use of in situ hybridization and immunohistochemistry, we detected infection by PRRSV in the testes of these boars. The PRRSV testicular replication in testis centers on two types of cells: (i) epithelial germ cells of the …


Irf-7, A New Interferon Regulatory Factor Associated With Epstein-Barr Virus Latency, Luwen Zhang, Joseph S. Pagano Oct 1997

Irf-7, A New Interferon Regulatory Factor Associated With Epstein-Barr Virus Latency, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

The Epstein-Barr virus (EBV) BamHI Q promoter (Qp) is the only promoter used for the transcription of Epstein-Barr virus nuclear antigen 1 (EBNA-1) mRNA in cells in the most restricted (type I) latent infection state. However, Qp is inactive in type III latency. With the use of the yeast one-hybrid system, a new cellular gene has been identified that encodes proteins which bind to sequence in Qp. The deduced amino acid sequence of the gene has significant homology to the interferon regulatory factors (IRFs). This new gene and products including two splicing variants are designated IRF-7A, IRF-7B, and IRF-7C. The …


Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole Jun 1997

Identification Of A Novel Antiapoptotic Functional Domain In Simian Virus 40 Large T Antigen., Suzanne D. Conzen, Christine A. Snay, Charles N. Cole

Dartmouth Scholarship

The ability of DNA tumor virus proteins to trigger apoptosis in mammalian cells is well established. For example, transgenic expression of a simian virus 40 (SV40) T-antigen N-terminal fragment (N-termTag) is known to induce apoptosis in choroid plexus epithelial cells. SV40 T-antigen-induced apoptosis has generally been considered to be a p53-dependent event because cell death in the brain is greatly diminished in a p53-/- background strain and is abrogated by expression of wild-type (p53-binding) SV40 T antigen. We now show that while N-termTags triggered apoptosis in rat embryo fibroblasts cultured in low serum, expression of full-length T antigens unable to …


Transcriptional Patterns Of The Pcd41 (U27) Locus Of Human Herpesvirus 6, Yi Zhou, Bala Chandran, Charles Wood May 1997

Transcriptional Patterns Of The Pcd41 (U27) Locus Of Human Herpesvirus 6, Yi Zhou, Bala Chandran, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 6 (HHV-6) is a lymphotropic herpesvirus, and in vitro, it can productively infect many of the same cell types that human immunodeficiency virus (HIV) infects. Simultaneous infection of T cells by HIV and HHV-6 can lead to both activation of the HIV promoter and acceleration of the cytopathic effects. Several HHV-6 genes have been demonstrated to activate HIV promoter expression. Among them is a cDNA clone, pCD41 (U27), which codes for the HHV-6 DNA polymerase accessory protein. We have now further characterized the transcription pattern in the pCD41 locus and identified at least six RNA species, ranging in …


Immune Suppression In Calves With Bovine Immunodeficiency Virus, Shucheng Zhang, Charles Wood, Wenzhi Xue, Samuel Krukenberg, Qimin Chen, Harish Minocha Mar 1997

Immune Suppression In Calves With Bovine Immunodeficiency Virus, Shucheng Zhang, Charles Wood, Wenzhi Xue, Samuel Krukenberg, Qimin Chen, Harish Minocha

Nebraska Center for Virology: Faculty Publications

The present study was designed to evaluate the effect of bovine immunodeficiency virus (BIV) infection on immune functions and possible interactions between BIV and other bovine viruses in calves. Ten calves were inoculated intravenously with BIV, and five served as controls. An increased lymphocyte proliferation to BIV gag protein was demonstrated 2 to 6 weeks after BIV inoculation (P < 0.05). Lymphocyte subset differentiation revealed a decreased CD4/CD8 ratio (P < 0.05) during weeks 2 to 7, suggesting a possible immune dysfunction in BIV-infected calves. When the calves were inoculated with bovine herpesvirus type 1 (BHV-1), the antibody response to BHV-1 in BIV-infected calves was delayed and the antibody titers were significantly lower (P < 0.05). Injection of bovine viral diarrhea virus vaccine also elicited a lower neutralizing antibody response in BIV-infected calves. The results indicated that immune suppression occurred in BIV-infected calves.


Encapsidation Of Turnip Crinkle Virus Is Defined By A Specific Packaging Signal And Rna Size, Feng Qu, Thomas Jack Morris Feb 1997

Encapsidation Of Turnip Crinkle Virus Is Defined By A Specific Packaging Signal And Rna Size, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

A protoplast infection assay has been used to reliably examine the viral RNA encapsidation of turnip crinkle virus (TCV). Analysis of the encapsidation of various mutant viral RNAs revealed that a 186-nucleotide (nt) region at the 3’ end of the coat protein (CP) gene, with a bulged hairpin loop of 28 nt as its most essential element, was indispensable for TCV RNA encapsidation. When RNA fragments containing the 186-nt region were used to replace the CP gene of a different virus, tomato bushy stunt virus, the resulting chimeric viral RNAs were encapsidated into TCV virions. Furthermore, analysis of the encapsidated …


Detection Of Bovine Immunodeficiency Virus Antibodies In Cattle By Western Blot Assay With Recombinant Gag Protein, Shucheng Zhang, Wenzhi Xue, Charles Wood, Qi-Min Chen, Sanjay Capil, Harish Minocha Jan 1997

Detection Of Bovine Immunodeficiency Virus Antibodies In Cattle By Western Blot Assay With Recombinant Gag Protein, Shucheng Zhang, Wenzhi Xue, Charles Wood, Qi-Min Chen, Sanjay Capil, Harish Minocha

Nebraska Center for Virology: Faculty Publications

A western blot assay using purified recombinant bovine immunodeficiency virus gag protein has been developed for detection of bovine immunodeficiency virus antibodies in bovine serum samples. The test was standardized with known bovine immunodeficiency virus positive and negative bovine serum samples and the monoclonal antibody to gag protein. Both naturally and experimentally infected cattle sera demonstrated positive test results. The result of western blot assay was compared with polymerase chain reaction test results in 134 blood samples collected from Kansas. Twenty-six samples tested positive for bovine immunodeficiency virus DNA with polymerase chain reaction (18.7%) and 25 were positive for the …


Testability Properties Of Divergent Trees, Ronald D. Blanton, John P. Hayes Jan 1997

Testability Properties Of Divergent Trees, Ronald D. Blanton, John P. Hayes

University Faculty Publications and Creative Works

The testability of a class of regular circuits called divergent trees is investigated under a functional fault model. Divergent trees include such practical circuits as decoders and demultiplexers. We prove that uncontrolled divergent trees are testable with a fixed number of test patterns (C-testable) if and only if the module function is surjective. Testable controlled trees are also surjective but require sensitizing vectors for error propagation. We derive the conditions for testing controlled divergent trees with a test set whose size is proportional to the number of levels p found in the tree (L-testability). By viewing a tree as overlapping …


Altered Pathogenesis Of A Mutant Of The Murine Coronavirus Mhv-A59 Is Associated With A Q159l Amino Acid Substitution In The Spike Protein, Isabelle Leparc-Goffart, Susan T. Hingley, Ming Chua, Xinhe Jiang, Ehud Lavi, Susan R. Weiss Jan 1997

Altered Pathogenesis Of A Mutant Of The Murine Coronavirus Mhv-A59 Is Associated With A Q159l Amino Acid Substitution In The Spike Protein, Isabelle Leparc-Goffart, Susan T. Hingley, Ming Chua, Xinhe Jiang, Ehud Lavi, Susan R. Weiss

PCOM Scholarly Papers

C12, an attenuated, fusion delayed, very weakly hepatotropic mutant of mouse hepatitis virus strain A59 (MHV-A59) has been further characterized. We have previously shown that C12 has two amino acid substitutions relative to wild type virus in the spike protein, Q159L (within a region of S1 shown to bind to viral receptor in an in vitro assay) and H716D (in the proteolytic cleavage recognition site). We have sequenced the rest of the 31-kb genome of C12 and compared it to wild type virus. Only three additional amino acids substitutions were found, all encoded within the replicase gene. Analysis of C12 …