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Articles 391 - 420 of 493

Full-Text Articles in Microbiology

Construction And Characterization Of A Chimeric Virus (Biv/Hiv-1) Carrying The Bovine Immunodeficiency Virus Gag-Pol Gene: Research Letters, Guomin Chen, Shuhui Wang, Kun Xiong, Jinzhong Wang, Tao Ye, Wenping Dong, Qi Wang, Qimin Chen, Yunqi Geng, Charles Wood, Yi Zeng Jan 2002

Construction And Characterization Of A Chimeric Virus (Biv/Hiv-1) Carrying The Bovine Immunodeficiency Virus Gag-Pol Gene: Research Letters, Guomin Chen, Shuhui Wang, Kun Xiong, Jinzhong Wang, Tao Ye, Wenping Dong, Qi Wang, Qimin Chen, Yunqi Geng, Charles Wood, Yi Zeng

Nebraska Center for Virology: Faculty Publications

HIV-1HXB2 5′LTR region, most of BIVR29 gag-pol segment and HIV-1HXB2 pol IN-3′LTR region were respectively amplified. A chimeric clone, designated as pHBIV3753, was constructed by cloning three fragments sequentially into pUC18. MT4 cells were transfected with pHBIV3753. The replication and expressions of the chimeric virus (HBIV3753) were monitored by RT activity and IFA. The results firstly demonstrated that it is possible to generate a new type of the BIV/HIV-1 chimeric virus containing BIV gag-pol gene.


Characterization Of Cd4-Induced Epitopes On The Hiv Type 1 Gp120 Envelope Glycoprotein Recognized By Neutralizing Human Monoclonal Antibodies, Shi-Hua Xiang, Najah Doka, Rabeéa K. Choudhary, Joseph Sodroski, James E. Robinson Jan 2002

Characterization Of Cd4-Induced Epitopes On The Hiv Type 1 Gp120 Envelope Glycoprotein Recognized By Neutralizing Human Monoclonal Antibodies, Shi-Hua Xiang, Najah Doka, Rabeéa K. Choudhary, Joseph Sodroski, James E. Robinson

Nebraska Center for Virology: Faculty Publications

The entry of human immunodeficiency virus (HIV-1) into target cells typically requires the sequential binding of the viral exterior envelope glycoprotein, gp120, to CD4 and a chemokine receptor. CD4 binding exposes gp120 epitopes recognized by CD4-induced (CD4i) antibodies, which can block virus binding to the chemokine receptor. We identified three new CD4i antibodies from an HIV-1-infected individual and localized their epitopes. These epitopes include a highly conserved gp120 β-strand encompassing residues 419–424, which is also important for binding to the CCR5 chemokine receptor. All of the CD4i antibodies inhibited the binding of gp120–CD4 complexes to CCR5. CD4i antibodies and …


The Genome Of Swinepox Virus, C. L. Afonso, E. R. Tulman, Z. Lu, L. Zsak, Fernando A. Osorio, C. Balinsky, G. F. Kutish, D. L. Rock Jan 2002

The Genome Of Swinepox Virus, C. L. Afonso, E. R. Tulman, Z. Lu, L. Zsak, Fernando A. Osorio, C. Balinsky, G. F. Kutish, D. L. Rock

Nebraska Center for Virology: Faculty Publications

Swinepox virus (SWPV), the sole member of the Suipoxvirus genus of the Poxviridae, is the etiologic agent of a worldwide disease specific for swine. Here we report the genomic sequence of SWPV. The 146-kbp SWPV genome consists of a central coding region bounded by identical 3.7-kbp inverted terminal repeats and contains 150 putative genes. Comparison of SWPV with chordopoxviruses reveals 146 conserved genes encoding proteins involved in basic replicative functions, viral virulence, host range, and immune evasion. Notably, these include genes with similarity to genes for gamma interferon (IFN-γ) receptor, IFN resistance protein, interleukin-18 binding protein, IFN-α/β binding protein, …


Mutagenic Stabilization And/Or Disruption Of A Cd4-Bound State Reveals Distinct Conformations Of The Human Immunodeficiency Virus Type 1 Gp120 Envelope Glycoprotein, Shi-Hua Xiang, Peter D. Kwong, Rishi Gupta, Carlo D. Rizzuto, David J. Casper, Richard Wyatt, Liping Wang, Wayne A. Hendrickson, Michael L. Doyle, Joseph Sodroski Jan 2002

Mutagenic Stabilization And/Or Disruption Of A Cd4-Bound State Reveals Distinct Conformations Of The Human Immunodeficiency Virus Type 1 Gp120 Envelope Glycoprotein, Shi-Hua Xiang, Peter D. Kwong, Rishi Gupta, Carlo D. Rizzuto, David J. Casper, Richard Wyatt, Liping Wang, Wayne A. Hendrickson, Michael L. Doyle, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The human immunodeficiency virus type 1 (HIV-1) gp120 exterior envelope glycoprotein is conformationally flexible. Upon binding to the host cell receptor CD4, gp120 assumes a conformation that is recognized by the second receptor, CCR5 and/or CXCR4, and by the CD4-induced (CD4i) antibodies. Guided by the X-ray crystal structure of a gp120-CD4-CD4i antibody complex, we introduced changes into gp120 that were designed to stabilize or disrupt this conformation. One mutant, 375 S/W, in which the tryptophan indole group is predicted to occupy the Phe 43 cavity in the gp120 interior, apparently favors a gp120 conformation closer to that of the CD4-bound …


Human Immunodeficiency Virus Type 1 (Hiv-1) Tat Induces Nitric-Oxide Synthase In Human Astroglia, Xiaojuan Liu, Malabendu Jana, Subhajit Dasgupta, Sreenivas Koka, Jun He, Charles Wood, Kalipada Pahan Jan 2002

Human Immunodeficiency Virus Type 1 (Hiv-1) Tat Induces Nitric-Oxide Synthase In Human Astroglia, Xiaojuan Liu, Malabendu Jana, Subhajit Dasgupta, Sreenivas Koka, Jun He, Charles Wood, Kalipada Pahan

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) infection is known to cause neuronal injury and dementia in a significant proportion of patients. However, the mechanism by which HIV-1 mediates its deleterious effects in the brain is poorly defined. The present study was undertaken to investigate the effect of the HIV-1 tat gene on the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astroglia. Expression of the tat gene as RSV- tat but not that of the CAT gene as RSV-CAT in U373MG astroglial cells led to the induction of NO production and the expression of iNOS …


Gemfibrozil, A Lipid-Lowering Drug, Inhibits The Induction Of Nitric-Oxide Synthase In Human Astrocytes, Kalipada Pahan, Malabendu Jana, Xiaojuan Liu, Bradley S. Taylor, Charles Wood, Susan M. Fischer Jan 2002

Gemfibrozil, A Lipid-Lowering Drug, Inhibits The Induction Of Nitric-Oxide Synthase In Human Astrocytes, Kalipada Pahan, Malabendu Jana, Xiaojuan Liu, Bradley S. Taylor, Charles Wood, Susan M. Fischer

Nebraska Center for Virology: Faculty Publications

Gemfibrozil, a lipid-lowering drug, inhibited cytokine- induced production of NO and the expression of inducible nitric-oxide synthase (iNOS) in human U373MG astroglial cells and primary astrocytes. Similar to gemfibrozil, clofibrate, another fibrate drug, also inhibited the expression of iNOS. Inhibition of human iNOS promoter-driven luciferase activity by gemfibrozil in cytokine-stimulated U373MG astroglial cells suggests that this compound inhibits the transcription of iNOS. Since gemfibrozil is known to activate peroxisome proliferator- activated receptor-α (PPAR-α), we investigated the role of PPAR- α in gemfibrozil-mediated inhibition of iNOS. Gemfibrozil induced peroxisome proliferator-responsive element (PPRE)-dependent luciferase activity, which was inhibited by the expression of …


Efficient Infection Of Nicotiana Benthamiana By Tomato Bushy Stunt Virus Is Facilitated By The Coat Protein And Maintained By P19 Through Suppression Of Gene Silencing, Feng Qu, Thomas Jack Morris Jan 2002

Efficient Infection Of Nicotiana Benthamiana By Tomato Bushy Stunt Virus Is Facilitated By The Coat Protein And Maintained By P19 Through Suppression Of Gene Silencing, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

Tomato bushy stunt virus (TBSV) is one of few RNA plant viruses capable of moving systemically in some hosts in the absence of coat protein (CP). TBSV also encodes another protein (p19) that is not required for systemic movement but functions as a symptom determinant in Nicotiana benthamiana. Here, the role of both CP and p19 in the systemic spread has been reevaluated by utilizing transgenic N. benthamiana plants expressing the movement protein (MP) of Red clover necrotic mosaic virus and chimeric TBSV mutants that express CP of Turnip crinkle virus. Through careful examination of the infection phenotype …


Phylogenetic And Phenotypic Analysis Of Hiv Type 1 Env Gp120 In Cases Of Subtype C Mother-To-Child Transmission, Hong Zhang, Guillermo Ortí, Qiujiang Du, Jun He, Chipepo Kankasa, Ganapati Bhat, Charles Wood Jan 2002

Phylogenetic And Phenotypic Analysis Of Hiv Type 1 Env Gp120 In Cases Of Subtype C Mother-To-Child Transmission, Hong Zhang, Guillermo Ortí, Qiujiang Du, Jun He, Chipepo Kankasa, Ganapati Bhat, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) subtype C constitutes a majority of the newly transmitted cases of HIV-1 in many developing countries. There is growing evidence suggesting that subtype C viruses may display characteristics that make them distinct from subtype B and other subtypes, and such differences may affect its transmission and pathogenesis in infected individuals. In this study, HIV-1 sequences from the C2–V4 region of the envelope gene were analyzed from four infected mother–infant pairs (MIPs) after perinatal transmission in Zambia. We found that all viral isolates from four Zambian MIPs were of the subtype C HIV-1 subgroup. All …


Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban Jan 2002

Small Glutamine-Rich Protein/Viral Protein U–Binding Protein Is A Novel Cochaperone That Affects Heat Shock Protein 70 Activity, Peter C. Angeletti, Doriann Walker, Antonito T. Panganiban

Nebraska Center for Virology: Faculty Publications

Molecular chaperone complexes containing heat shock protein (Hsp) 70 and Hsp90 are regulated by cochaperones, including a subclass of regulators, such as Hsp70 interacting protein (Hip), C-terminus of Hsp70 interacting protein (CHIP), and Hsp70-Hsp90 organizing factor (Hop), that contain tetratricopeptide repeats (TPRs), where Hsp70 refers to Hsp70 and its nearly identical constitutive counterpart, Hsc70, together. These proteins interact with the Hsp70 to regulate adenosine triphosphatase (ATPase) and folding activities or to generate the chaperone complex. Here we provide evidence that small glutamine-rich protein/viral protein U–binding protein (SGT/UBP) is a cochaperone that negatively regulates Hsp70. By “Far-Western” and pull-down assays, SGT/UBP …


Cellular Tropisms And Co-Receptor Usage Of Hiv-1 Isolates From Vertically Infected Children With Neurological Abnormalities And Rapid Disease Progression, Micheline Mccarthy, Jun He, Denise Auger, Rebeca Geffin, Cecilia Hutto, Charles Wood, Gwendolyn Scott Jan 2002

Cellular Tropisms And Co-Receptor Usage Of Hiv-1 Isolates From Vertically Infected Children With Neurological Abnormalities And Rapid Disease Progression, Micheline Mccarthy, Jun He, Denise Auger, Rebeca Geffin, Cecilia Hutto, Charles Wood, Gwendolyn Scott

Nebraska Center for Virology: Faculty Publications

The longitudinal evolution of HIV-1 phenotypes was studied in a cohort of six vertically infected children with early onset and rapid progression of clinical disease. Among 30 viral isolates obtained from peripheral blood, tropisms for both human blood-derived cells (macrophages, T-lymphocytes), and for human neural (brain-derived) cells (microglia, astrocytes) were determined, as was chemokine co-receptor usage. All children harbored from birth macrophage-tropic isolates using the CCR5 co-receptor. Two children later developed T-cell tropic isolates with CXCR4 and CCR3 usage. While all six patients developed neurological abnormalities, only three produced neural cell tropic isolates, which used CCR5. However, early and persistent …


Intracellular Signaling Molecules Activated By Epstein-Barr Virus For Induction Of Interferon Regulatory Factor 7, Luwen Zhang, Lihong Wu, Ke Hong, Joseph S. Pagano Dec 2001

Intracellular Signaling Molecules Activated By Epstein-Barr Virus For Induction Of Interferon Regulatory Factor 7, Luwen Zhang, Lihong Wu, Ke Hong, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) is the principal oncogenic protein in the EBV transformation process. LMP-1 induces the expression of interferon regulatory factor 7 (IRF-7) and activates IRF-7 protein by phosphorylation and nuclear translocation. LMP-1 is an integral membrane protein with two regions in its C terminus that initiate signaling processes, the C-terminal activator regions 1 (CTAR-1) and CTAR-2. Here, genetic analysis of LMP-1 has determined that the PXQXT motif that governs the interaction between LMP-1 CTAR-1 and tumor necrosis factor receptor-associated factors (TRAFs) is needed to induce the expression of IRF-7. Mutations in the PXQXT motif …


Interferon Regulatory Factor 7: A Key Cellular Mediator Of Lmp-1 In Ebv Latency And Transformation, Luwen Zhang, Joseph S. Pagano Dec 2001

Interferon Regulatory Factor 7: A Key Cellular Mediator Of Lmp-1 In Ebv Latency And Transformation, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Interferon regulatory factor 7 (IRF-7) was cloned within the biological context of Epstein–Barr virus (EBV) latency, and has an intimate relation with EBV. EBV latent membrane protein 1 (LMP-1) regulates IRF-7 both by inducing the expression of IRF-7 and by activating IRF-7 protein through phosphorylation and nuclear translocation in a post-translational manner. The activated IRF-7 then functions to regulate both EBV and cellular target genes involved in latency, transformation and immune regulation. IRF-7 appears to be a key cellular latency protein involved in both the pathogenesis and persistence of EBV infection.


Identification Of A Cellular Protein That Interacts And Synergizes With The Rta (Orf50) Protein Of Kaposi’S Sarcoma-Associated Herpesvirus In Transcriptional Activation, Shizhen Wang, Shuhong Liu, Ming-Hoi Wu, Yunqi Geng, Charles Wood Dec 2001

Identification Of A Cellular Protein That Interacts And Synergizes With The Rta (Orf50) Protein Of Kaposi’S Sarcoma-Associated Herpesvirus In Transcriptional Activation, Shizhen Wang, Shuhong Liu, Ming-Hoi Wu, Yunqi Geng, Charles Wood

Nebraska Center for Virology: Faculty Publications

Lytic reactivation of Kaposi’s sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, from latency requires transcriptional transactivation by the viral protein RTA encoded by the ORF50 gene. Very little is known about how RTA functions and the cellular factors that may be involved in its transactivation function. Using the yeast two-hybrid system, we have identified a human cellular protein that can interact with KSHV RTA. The cellular protein, referred to as the human hypothetical protein MGC2663 by GenBank, is encoded by human chromosome 19. This protein is 554 amino acids (aa) in size and displays sequence similarity with members of the …


Mononuclear Phagocyte Differentiation, Activation, And Viral Infection Regulate Matrix Metalloproteinase Expression: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Anuja Ghorpade, Raisa Persidskaia, Radhika Suryadevara, Myhanh Che, Xiao Juan Liu, Yuri Persidsky, Howard Gendelman Jul 2001

Mononuclear Phagocyte Differentiation, Activation, And Viral Infection Regulate Matrix Metalloproteinase Expression: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Anuja Ghorpade, Raisa Persidskaia, Radhika Suryadevara, Myhanh Che, Xiao Juan Liu, Yuri Persidsky, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

The pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is mediated mainly by mononuclear phagocyte (MP) secretory products and their interactions with neural cells. Viral infection and MP immune activation may affect leukocyte entry into the brain. One factor that influences central nervous system (CNS) monocyte migration is matrix metalloproteinases (MMPs). In the CNS, MMPs are synthesized by resident glial cells and affect the integrity of the neuropil extracellular matrix (ECM). To ascertain how MMPs influence HAD pathogenesis, we studied their secretion following MP differentiation, viral infection, and cellular activation. HIV-1-infected and/or immune-activated monocyte-derived macrophages (MDM) and human …


Regulation Of Human Immunodeficiency Virus Type 1 Infection, Β-Chemokine Production, And Ccr5 Expression In Cd40l-Stimulated Macrophages: Immune Control Of Viral Entry, Robin L. Cutter, Jialin Zheng, Myhanh Che, Douglas Niemann, Ying Liu, Johnny He, Elaine Thomas, Howard Gendelman May 2001

Regulation Of Human Immunodeficiency Virus Type 1 Infection, Β-Chemokine Production, And Ccr5 Expression In Cd40l-Stimulated Macrophages: Immune Control Of Viral Entry, Robin L. Cutter, Jialin Zheng, Myhanh Che, Douglas Niemann, Ying Liu, Johnny He, Elaine Thomas, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Mononuclear phagocytes (MP) and T lymphocytes play a pivotal role in the host immune response to human immunodeficiency virus type 1 (HIV-1) infection. Regulation of such immune responses can be mediated, in part, through the interaction of the T-lymphocyte-expressed molecule CD40 ligand (CD40L) with its receptor on MP, CD40. Upregulation of CD40L on CD4+ peripheral blood mononuclear cells during advanced HIV-1 disease has previously been reported. Based on this observation, we studied the influence of CD40L-CD40 interactions on MP effector function and viral regulation in vitro. We monitored productive viral infection, cytokine and β -chemokine production, and β-chemokine receptor …


Human Papillomavirus Virus-Like Particles Are Efficient Oral Immunogens When Coadministered With Escherichia Coli Heat-Labile Enterotoxin Mutant R192g Or Cpg Dna, S. Gerber, C. Lane, Deborah M. Brown, E. Lord, M. Dilorenzo, J. D. Clements, E. Rybicki, A.-L. Williamson, R. C. Rose May 2001

Human Papillomavirus Virus-Like Particles Are Efficient Oral Immunogens When Coadministered With Escherichia Coli Heat-Labile Enterotoxin Mutant R192g Or Cpg Dna, S. Gerber, C. Lane, Deborah M. Brown, E. Lord, M. Dilorenzo, J. D. Clements, E. Rybicki, A.-L. Williamson, R. C. Rose

Nebraska Center for Virology: Faculty Publications

Certain human papillomaviruses (HPVs) cause most cervical cancer, which remains a significant source of morbidity and mortality among women worldwide. HPV recombinant virus-like particles (VLPs) are promising vaccine candidates for controlling anogenital HPV disease and are now being evaluated as a parenteral vaccine modality in human subjects. Vaccines formulated for injection generally are more costly, more difficult to administer, and less acceptable to recipients than are mucosally administered vaccines. Since oral delivery represents an attractive alternative to parenteral injection for large-scale human vaccination, the oral immunogenicity of HPV type 11 (HPV-11) VLPs in mice was previously investigated; it was found …


Differentiation Of Two Bovine Lentiviruses By A Monoclonal Antibody On The Basis Of Epitope Specificity, Ling Zheng, Shucheng Zhang, Charles Wood, Sanjay Kapil, Graham E. Wilcox, Thomas A. Loughlin, H. C. Minocha Mar 2001

Differentiation Of Two Bovine Lentiviruses By A Monoclonal Antibody On The Basis Of Epitope Specificity, Ling Zheng, Shucheng Zhang, Charles Wood, Sanjay Kapil, Graham E. Wilcox, Thomas A. Loughlin, H. C. Minocha

Nebraska Center for Virology: Faculty Publications

Bovine immunodeficiency virus (BIV) and Jembrana disease virus (JDV) are bovine lentiviruses that are closely related genetically. A recombinant fusion protein containing the capsid protein of BIV expressed in Escherichia coli was used to immunize mice and produce monoclonal antibodies. Six hybridomas specific for BIV capsid protein were identified, and one antibody, designated 10H1, was characterized further. Competitive binding assays were performed to analyze the topography of antigenic determinants by enzyme-linked immunosorbent assay and demonstrated the existence of at least three distinct antigenic determinants on capsid protein. The monoclonal antibody reacted specifically with both BIV capsid and the recombinant fusion …


Genetic And Biological Variation In Equine Infectious Anemia, Michael Belshan, Prasith Baccum, J. Lindsay Oaks, Brett A. Sponseller, Sean C. Murphy, James Cornette, Susan Carpenter Jan 2001

Genetic And Biological Variation In Equine Infectious Anemia, Michael Belshan, Prasith Baccum, J. Lindsay Oaks, Brett A. Sponseller, Sean C. Murphy, James Cornette, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

Genetic and biological variation in the regulatory protein Rev of equine infectious anemia virus (EIAV) were examined throughout a clinically dynamic disease course of an experimentally infected pony. Following infection with the virulent EIAVWyo, the pony underwent a variable disease course, including an acute fever episode at 12 days postinfection (DPI), multiple recurrent fever episodes until 135 DPI, a prolonged subclinical period, and two late fever episodes. Viral RNA was isolated from the inoculum and sequential sera samples, and the rev exon 2/gp45 overlapping ORFs were amplified, cloned, and sequenced. Novel variants were found throughout infection, and genetic …


Vertical Transmission Of Kaposi's Sarcoma-Associated Herpesvirus, Hamakwa Mantina, Chipepo Kankasa, Winslow Klaskala, Brad Brayfield, James Campbell, Quijiang Du, Ganapati Bhat, Francis Kasolo, Charles Mitchell, Charles Wood Jan 2001

Vertical Transmission Of Kaposi's Sarcoma-Associated Herpesvirus, Hamakwa Mantina, Chipepo Kankasa, Winslow Klaskala, Brad Brayfield, James Campbell, Quijiang Du, Ganapati Bhat, Francis Kasolo, Charles Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Little is presently known about the specific routes of transmission of Kaposi’s sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain …


Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood Jan 2001

Human Herpesvirus 8 Can Be Transmitted Through Blood In Drug Addicts, Carlos Sosa, Jorge Benetucci, Colleen Hanna, Laura Sieczkowski, Gabriel Deluchi, Ana Maria Canizal, Hamakwa Mantina, Winslow Klaskala, Marianna Baum, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human Herpes virus type-8 (HHV-8) seroprevalence was studied in a population of HIV positive intravenous drug users (IVDUs) from Argentina. Analysis of this population also indirectly made it possible to study HHV-8 blood transmission, because these individuals frequently engage in needle sharing behavior and are capable of acquiring a broad array of blood borne pathogens, including Hepatitis B/C virus. The seroprevalence of HHV-8 in IVDUs was compared to a group of non-IVDUs and HIV negative individuals. Of the 223 individuals tested, 13.45% were HHV-8 positive, 16.99% in the IVDUs group, and 5.71% in the non-IVDUs. Among HIV positive IVDUs, 25/144 …


Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano Jan 2001

Interferon Regulatory Factor 7 Mediates Activation Of Tap-2 By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagano

Nebraska Center for Virology: Faculty Publications

Transporter associated with antigen processing 2 (Tap-2) is responsible for ATP-dependent transport of peptides from the cytosol to the endoplasmic reticulum, where peptides bind to newly synthesized human leukocyte antigen (HLA) class I molecules, which are essential for cellular immune responses. Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) has been shown to induce the expression of Tap-2. In this study, the induction of endogenous Tap-2 by LMP-1 is shown to be associated with and requires the expression of interferon regulatory factor 7 (IRF-7). In DG75 Burkitt’s lymphoma (BL) cells, in which LMP-1 induces the expression of IRF-7, LMP-1 induced …


Characterization Of Transcripts Expressed From Human Herpesvirus 6a Strain Gs Immediate-Early Region B U16-U17 Open Reading Frames, Linda Flebbe-Rehwaldt, Charles Wood, Bala Chandran Dec 2000

Characterization Of Transcripts Expressed From Human Herpesvirus 6a Strain Gs Immediate-Early Region B U16-U17 Open Reading Frames, Linda Flebbe-Rehwaldt, Charles Wood, Bala Chandran

Nebraska Center for Virology: Faculty Publications

Several gene fragments of human herpesvirus 6 (HHV-6) have been shown to activate the human immunodeficiency virus (HIV) type 1 long terminal repeat (LTR). An open reading frame (ORF) designated B701 (Y. Geng, B. Chandran, S. F. Josephs, and C. Wood, J. Virol. 66:1564–1570, 1992), found within a 22-kb HHV-6A strain GS [HHV-6A(GS)] genomic fragment and a 3.8-kb SalI subfragment, was shown to activate the HIV LTR. B701, also known as HHV-6 U16, is located in the immediate-early B (IE-B) region of the genome. The sequence of the 3.8-kb genomic fragment of HHV-6A(GS) is nearly identical to the published …


Porcine Reproductive And Respiratory Syndrome Virus: Description Of Persistence In Individual Pigs Upon Experimental Infection, R. Allende, W. W. Laegreid, G. F. Kutish, J. A. Galeota, R. W. Wills, Fernando A. Osorio Nov 2000

Porcine Reproductive And Respiratory Syndrome Virus: Description Of Persistence In Individual Pigs Upon Experimental Infection, R. Allende, W. W. Laegreid, G. F. Kutish, J. A. Galeota, R. W. Wills, Fernando A. Osorio

Nebraska Center for Virology: Faculty Publications

We studied the persistence of porcine reproductive and respiratory syndrome virus (PRRSV) in individual experimentally infected pigs, during a period of up to 150 days postinfection (dpi). The results of this study suggest that the persistence of PRRSV involves continuous viral replication but that it is not a true steady-state persistent infection. The virus eventually clears the body and seems to do it in most of the animals by 150 dpi or shortly thereafter. High genetic stability was seen for several regions of the persistent PRRSV’s genome, although some consistent mutations in the genes of envelope glycoproteins and M protein …


Cloning Of The Bovine Immunodeficiency Virus Gag Gene And Development Of A Recombinant-Protein-Based Enzyme-Linked Immunosorbent Assay, Ling Zheng, Michelle Swanson, Jinghua Liao, Charles Wood, Sanjay Kapil, Ron Snider, Thomas A. Loughin, Harish Minocha Jul 2000

Cloning Of The Bovine Immunodeficiency Virus Gag Gene And Development Of A Recombinant-Protein-Based Enzyme-Linked Immunosorbent Assay, Ling Zheng, Michelle Swanson, Jinghua Liao, Charles Wood, Sanjay Kapil, Ron Snider, Thomas A. Loughin, Harish Minocha

Nebraska Center for Virology: Faculty Publications

An enzyme-linked immunosorbent assay (ELISA) was established for the rapid detection of specific bovine immunodeficiency virus (BIV) antibodies in cattle, using recombinant Gag protein as an antigen. The gag coding region from BIV was cloned into an expression vector, pQE32, which expressed high levels of recombinant protein from Escherichia coli. The ELISA was standardized by a checkerboard titration against known BIV-positive and -negative sera from cattle and a monoclonal antibody to the Gag protein. A total of 139 cattle serum samples, from the diagnostic laboratory at Kansas State University, Manhattan, and from the Dairy Station, Louisiana State University, Baton …


Adaptation And Selection Of Prion Protein Strain Conformations Following Interspecies Transmission Of Transmissible Mink Encephalopathy, Jason C. Bartz, Richard Bessen, Debbie Mckenzie, Richard F. Marsh, Judd M. Aiken Jun 2000

Adaptation And Selection Of Prion Protein Strain Conformations Following Interspecies Transmission Of Transmissible Mink Encephalopathy, Jason C. Bartz, Richard Bessen, Debbie Mckenzie, Richard F. Marsh, Judd M. Aiken

Nebraska Center for Virology: Faculty Publications

Interspecies transmission of the transmissible spongiform encephalopathies (TSEs), or prion diseases, can result in the adaptation and selection of TSE strains with an expanded host range and increased virulence such as in the case of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease. To investigate TSE strain adaptation, we serially passaged a biological clone of transmissible mink encephalopathy (TME) into Syrian golden hamsters and examined the selection of distinct strain phenotypes and conformations of the disease-specific isoform of the prion protein (PrPSc). The long-incubation-period drowsy (DY) TME strain was the predominate strain, based on the presence of its strain-specific …


Binding Of Equine Infectious Anemia Virus Rev To An Exon Splicing Enhancer Mediates Alternative Splicing And Nuclear Export Of Viral Mrnas, Michael Belshan, Gregory S. Park, Patricia Bilodeau, C. Martin Stoltzfus, Susan Carpenter May 2000

Binding Of Equine Infectious Anemia Virus Rev To An Exon Splicing Enhancer Mediates Alternative Splicing And Nuclear Export Of Viral Mrnas, Michael Belshan, Gregory S. Park, Patricia Bilodeau, C. Martin Stoltzfus, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

In addition to facilitating the nuclear export of incompletely spliced viral mRNAs, equine infectious anemia virus (EIAV) Rev regulates alternative splicing of the third exon of the tat/rev mRNA. In the presence of Rev, this exon of the bicistronic RNA is skipped in a fraction of the spliced mRNAs. In this report, the cis-acting requirements for exon 3 usage were correlated with sequences necessary for Rev binding and transport of incompletely spliced RNA. The presence of a purine-rich exon splicing enhancer (ESE) was required for exon 3 recognition, and the addition of Rev inhibited exon 3 splicing. Glutathione-S-transferase (GST)-Rev bound …


Jembrana Disease Virus Tat Can Regulate Human Immunodeficiency Virus (Hiv) Long Terminal Repeat-Directed Gene Expression And Can Substitute For Hiv Tat In Viral Replication, Hexin Chen, Jun He, Steven Fong, Graham Wilcox, Charles Wood Mar 2000

Jembrana Disease Virus Tat Can Regulate Human Immunodeficiency Virus (Hiv) Long Terminal Repeat-Directed Gene Expression And Can Substitute For Hiv Tat In Viral Replication, Hexin Chen, Jun He, Steven Fong, Graham Wilcox, Charles Wood

Nebraska Center for Virology: Faculty Publications

Jembrana disease virus (JDV) is a bovine lentivirus genetically similar to bovine immunodeficiency virus; it causes an acute and sometimes fatal disease in infected animals. This virus carries a very potent Tat that can strongly activate not only its own long terminal repeat (LTR) but also the human immunodeficiency virus (HIV) LTR. In contrast, HIV Tat cannot reciprocally activate the JDV LTR (H. Chen, G. E. Wilcox, G. Kertayadnya, and C. Wood, J. Virol. 73:658–666, 1999). This indicates that in transactivation JDV Tat may utilize a mechanism similar to but not the same as that of the HIV Tat. To …


Interferon Regulatory Factor 7 Is Induced By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagono Feb 2000

Interferon Regulatory Factor 7 Is Induced By Epstein-Barr Virus Latent Membrane Protein 1, Luwen Zhang, Joseph S. Pagono

Nebraska Center for Virology: Faculty Publications

Infection by Epstein-Barr virus (EBV) generates several types of latency with different profiles of gene expression but with expression of Epstein-Barr nuclear antigen 1 (EBNA-1) in common. The BamHI Q promoter (Qp) is used for the transcription of EBNA-1 mRNA in type I latency, which is an EBV infection state exemplified by Burkitt’s lymphoma (BL). However, Qp is inactive in type III latency, and other promoters (C/Wp) are used for transcription of EBNA-1, which raises the question of how usage of these promoters is governed. Interferon (IFN) regulatory factor 7 (IRF-7) was identified first as a negative regulator of …


Cap-Independent Translational Enhancement Of Turnip Crinkle Virus Genomic And Subgenomic Rnas, Feng Qu, Thomas Jack Morris Feb 2000

Cap-Independent Translational Enhancement Of Turnip Crinkle Virus Genomic And Subgenomic Rnas, Feng Qu, Thomas Jack Morris

Nebraska Center for Virology: Faculty Publications

The presence of translational control elements and cap structures has not been carefully investigated for members of the Carmovirus genus, a group of small icosahedral plant viruses with positive-sense RNA genomes. In this study, we examined both the 5’ and 3’ untranslated regions (UTRs) of the turnip crinkle carmovirus (TCV) genomic RNA (4 kb) as well as the 5’ UTR of the coat protein subgenomic RNA (1.45 kb) for their roles in translational regulation. All three UTRs enhanced translation of the firefly luciferase reporter gene to different extents. Optimal translational efficiency was achieved when mRNAs contained both 5’ and 3’ …


Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino Jan 2000

Identification Of The Transactivation Domain Of The Transcription Factor Sox-2 And An Associated Co-Activator, Tamara K. Nowling, Lance R. Johnson, Matthew S. Wiebe, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

The importance of interactions between Sox and POU transcription factors in the regulation of gene expression is becoming increasingly apparent. Recently, many examples of the involvement of Sox-POU partnerships in transcription have been discovered, including a partnership between Sox-2 and Oct-3. Little is known about the mechanisms by which these factors modulate transcription. To better understand the molecular interactions involved, we mapped the location of the transactivation do-main of Sox-2. This was done in the context of its interaction with Oct-3, as well as its ability to transactivate as a fusion protein linked to the DNA-binding domain of Gal4. Both …