Virology Commons^™

Transitions To And From The Cd4-Bound Conformation Are Modulated By A Single-Residue Change In The Human Immunodeficiency Virus Type 1 Gp120 Inner Domain, Aemro Kassa, Navid Madani, Arne Schön, Hillel Haim, Andrés Finzi, Shi-Hua Xiang, Liping Wang, Amy Princiotto, Marie Pancera, Joel Courter, Amos B. Smith Iii, Ernesto Freire, Peter D. Kwong, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Binding to the primary receptor CD4 induces conformational changes in the human immunodeficiency virus type 1 (HIV-1) gp120 envelope glycoprotein that allow binding to the coreceptor (CCR5 or CXCR4) and ultimately trigger viral membrane-cell membrane fusion mediated by the gp41 transmembrane envelope glycoprotein. Here we report the derivation of an HIV-1 gp120 variant, H66N, that confers envelope glycoprotein resistance to temperature extremes. The H66N change decreases the spontaneous sampling of the CD4-bound conformation by the HIV-1 envelope glycoproteins, thus diminishing CD4-independent infection. The H66N change also stabilizes the HIV-1 envelope glycoprotein complex once the CD4-bound state is achieved, decreasing the …

Comparison Of Replication-Competent, First Generation, And Helper-Dependent Adenoviral Vaccines, Eric A. Weaver, Pramod N. Nehete, Stephanie S. Buchl, Julien S. Senac, Donna Palmer, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

All studies using human serotype 5 Adenovirus (Ad) vectors must address two major obstacles: safety and the presence of pre-existing neutralizing antibodies. Helper-Dependent (HD) Ads have been proposed as alternative vectors for gene therapy and vaccine development because they have an improved safety profile. To evaluate the potential of HD-Ad vaccines, we compared replication-competent (RC), first-generation (FG) and HD vectors for their ability to induce immune responses in mice. We show that RC-Ad5 and HD-Ad5 vectors generate stronger immune responses than FG-Ad5 vectors. HD-Ad5 vectors gave lower side effects than RC or FG-Ad, producing lower levels of tissue damage and …

Biomarkers Of Hiv-1 Associated Dementia: Proteomic Investigation Of Sera, Jayme Wiederin, Wojciech Rozek, Fenghai Duan, Pawel Ciborowski

Nebraska Center for Virology: Faculty Publications

Background: New, more sensitive and specific biomarkers are needed to support other means of clinical diagnosis of neurodegenerative disorders. Proteomics technology is widely used in discovering new biomarkers. There are several difficulties with in-depth analysis of human plasma/ serum, including that there is no one proteomic platform that can offer complete identification of differences in proteomic profiles. Another set of problems is associated with heterogeneity of human samples in addition intrinsic variability associated with every step of proteomic investigation. Validation is the very last step of proteomic investigation and it is very often difficult to validate potential biomarker with desired …

X4 Human Immunodeficiency Virus Type 1 Gp120 Down-Modulates Expression And Immunogenicity Of Codelivered Antigens, Avi-Hai Hovav, Michael Santosuosso, Maytal Bivas-Benita, Andre Plair, Alex Cheng, Mazal Elnekave, Elda Righi, Tao Chen, Satoshi Kashiwagi, Michael W. Panas, Shi-Hua Xiang, Karina Furmanov, Norman L. Letvin, Mark C. Poznansky

Nebraska Center for Virology: Faculty Publications

In order to increase the immune breadth of human immunodeficiency virus (HIV) vaccines, strategies such

as immunization with several HIV antigens or centralized immunogens have been examined. HIV-1 gp120

protein is a major immunogen of HIV and has been routinely considered for inclusion in both present and

future AIDS vaccines. However, recent studies proposed that gp120 interferes with the generation of immune

response to codelivered antigens. Here, we investigate whether coimmunization with plasmid-encoded gp120

alters the immune response to other coadministered plasmid encoded antigens such as luciferase or ovalbumin

in a mouse model. We found that the presence of gp120 …

Identification And Characterization Of A New Kaposi’S Sarcoma-Associated Herpesvirus Replication And Transcription Activator (Rta)- Responsive Element Involved In Rta-Mediated Transactivation, Hui-Ju Wen, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) replication and transcription activator (RTA) is well established as a key transcriptional activator that regulates the KSHV life cycle from latency to lytic replication. It is expressed immediately after infection and activates a number of viral genes leading to virus replication. The RTA-responsive element (RRE) in the RTA target gene promoters is critical for RTA to mediate this transactivation. A number of non-conserved RREs have been identified in various RTA-responsive promoters, and AT-rich sequences have been proposed to serve as RTA targets, but no consensus RRE sequence has been identified so far. Two nonconserved RREs (RRE1 …

Comparison Of Replication-Competent, First Generation, And Helper-Dependent Adenoviral Vaccines, Eric A. Weaver, Pramod N. Nehete, Stephanie S. Buchl, Julien S. Senac, Donna Palmer, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

All studies using human serotype 5 Adenovirus (Ad) vectors must address two major obstacles: safety and the presence of pre-existing neutralizing antibodies. Helper-Dependent (HD) Ads have been proposed as alternative vectors for gene therapy and vaccine development because they have an improved safety profile. To evaluate the potential of HD-Ad vaccines, we compared replication-competent (RC), first-generation (FG) and HD vectors for their ability to induce immune responses in mice. We show that RC-Ad5 and HD-Ad5 vectors generate stronger immune responses than FG-Ad5 vectors. HD-Ad5 vectors gave lower side effects than RC or FG-Ad, producing lower levels of tissue damage and …

Human Ubc9 Contributes To Production Of Fully Infectious Human Immunodeficiency Virus Type 1 Virions, Tareq Jaber, Christopher R. Bohl, Gentry L. Lewis, Charles Wood, John T. West Jr., Robert A. Weldon Jr.

Nebraska Center for Virology: Faculty Publications

Ubc9 was identified as a cellular protein that interacts with the Gag protein of Mason-Pfizer monkey virus. We show here that Ubc9 also interacts with the human immunodeficiency virus type 1 (HIV-1) Gag protein and that their interaction is important for virus replication. Gag was found to colocalize with Ubc9 predominantly at perinuclear puncta. While cells in which Ubc9 expression was suppressed with RNA interference produced normal numbers of virions, these particles were 8- to 10-fold less infectious than those produced in the presence of Ubc9. The nature of this defect was assayed for dependence on Ubc9 during viral assembly, …

Expression Of Hpv16 E5 Produces Enlarged Nuclei And Polyploidy Through Endoreplication, Lulin Hu, Tamara A. Potapova, Shibo Li, Susannah Rankin, Gary J. Gorbsky, Peter C. Angeletti, Brian P. Ceresa

Nebraska Center for Virology: Faculty Publications

Anogenital cancers and head and neck cancers are causally-associated with infection by high-risk

human papillomavirus (HPV). The mechanism by which high-risk HPVs contribute to

oncogenesis is poorly understood. HPV16 encodes three genes (HPV16 E5, E6, and E7) that can

transform cells when expressed independently. HPV16 E6 and E7 have well-described roles

causing genomic instability and unregulated cell cycle progression. The role of HPV16 E5 in cell

transformation remains to be elucidated. Expression of HPV16 E5 results in enlarged, polyploid

nuclei that are dependent on the level and duration of HPV16 E5 expression. Live-cell imaging

data indicate these changes do not …

Human Papillomavirus 16 E5 Induces Bi-Nucleated Cell Formation By Cell-Cell Fusion, Lulin Ha, Kendra Plafker, Valeriya Vorozhoko, Rosemary E. Zuna, Marie H. Hanigan, Gary J. Gorbsky, Scott M. Plafker, Peter C. Angeletti, Brian P. Ceresa

Nebraska Center for Virology: Faculty Publications

Human Papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes – E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, …

A Comparative Study Of Hiv-1 Clade C Env Evolution In A Zambian Infant With An Infected Rhesus Macaque During Disease Progression, For Yue Tso, Federico G. Hoffmann, Damien C. Tully, Philippe Lemey, Robert A. Rasmussen, Hong Zhang, Ruth M. Ruprecht, Charles Wood

Nebraska Center for Virology: Faculty Publications

Objective—To evaluate whether HIV-1 clade C (HIV-C) envelope variations that arise during disease progression in rhesus macaque model reflect changes that occur naturally in human infection.

Design—An infant macaque was infected with SHIV-1157i, an R5 tropic clade C SHIV (SHIV-C) which expresses a primary HIV-C envelope derived from an infected human infant, and monitored over a five-year period. Genetic variation of the V1-V5 envelope region, which is the main target for humoral immune responses, derived from the infected macaque and infant was examined.

Methods—V1-V5 envelope region were cloned and sequenced from longitudinal PBMC samples collected from the infected macaque and …

Use Of Average Mutual Information For Studying Changes In Hiv Populations, Khalid Sayood, Federico Hoffman, Charles Wood

Nebraska Center for Virology: Faculty Publications

Average mutual information (AMI) has been used in a number of applications in bioinformatics. In this paper we present its use to study genetic changes in populations; in particular populations of HIV viruses. Disease progression of HIV-1 infection in infants can be rapid resulting in death within the the first year, or slow, allowing the infant to survive beyond the first year. We study the development of rapid and slow progressing HIV population using AMI charts based on average mutual information among amino acids in the env gene from a population of 1142 clones derived from seven infants with slow …

Protection Against Mucosal Shiv Challenge By Peptide And Helper-Dependent Adenovirus Vaccines, Eric A. Weaver, Pramod N. Nehete, Bharti P. Nehete, Stephanie J. Buchl, Donna Palmer, David C. Montefiori, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Groups of rhesus macaques that had previously been immunized with HIV-1 envelope (env) peptides and first generation adenovirus serotype 5 (FG-Ad5) vaccines expressing the same peptides were immunized intramuscularly three times with helper- dependent adenovirus (HD-Ad) vaccines expressing only the HIV-1 envelope from JRFL. No gag, pol, or other SHIV genes were used for vaccination. One group of the FG-Ad5- immune animals was immunized three times with HD-Ad5 expressing env. One group was immunized by serotype-switching with HD-Ad6, HD-Ad1, and HD-Ad2 expressing env. Previous work demonstrated that serum antibody levels against env were significantly higher in the serotype-switched group than …

Characterization Of A Monothiol Glutaredoxin Encoded By Chlorella Virus Pbcv-1, Lisa A. Fitzgerald, Yuanzheng Zhang, Gentry L. Lewis, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Annotation of the 330-kb Chlorella virus PBCV-1 genome identified a 237 nucleotide gene (a438l) that codes for a protein with ~35% amino acid identity to glutaredoxins (Grx) found in other organisms. The PBCV-1 protein resembles classical Grxs in both size (9 kDa) and location of the active site (N-terminus). However, the PBCV-1 Grx is unusual because it contains a monothiol active site (CPYS) rather than the typical dithiol active site (CPYC). To examine this unique active site, four sitespecific mutants (CPYC, CPYA, SPYC, and SPYS) were constructed to determine if the N-terminal cysteine is necessary for enzyme activity. …

The Zinc Finger Dna-Binding Domain Of K-Rbp Plays An Important Role In Regulating Kaposi’S Sarcoma-Associated Herpesvirus Rta-Mediated Gene Expression, Zhilong Yang, Hui-Ju Wen, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

K-RBP is a KRAB-containing zinc finger protein with multiple zinc finger motifs and represses Kaposi’s sarcoma-associated herpesvirus (KSHV) transactivator RTA-mediated transactivation of several viral lytic gene promoters, including the ORF57 promoter. Whether K-RBP binds DNA through its zinc fingers and the role of zinc finger domain in repressing gene expression are unclear. Here we report that K-RBP binds DNA through its zinc finger domain and the target DNA sequences contain high GC content. Furthermore, K-RBP binds to KSHV ORF57 promoter, which contains a GC-rich motif. K-RBP suppresses the basal ORF57 promoter activity as well as RTA-mediated activation. The zinc finger …

Effects Of Shielding Adenoviral Vectors With Polyethylene Glycol On Vector-Specific And Vaccine-Mediated Immune Responses, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Many individuals have been previously exposed to human adenovirus serotype 5 (Ad5). This prior immunity has long been known to hinder its use for gene therapy and as a gene-based vaccine. Given these immunogenicity problems, we have tested whether polyethylene glycol (PEG) can blunt immune effects against Ad5 during systemic and mucosal vaccination. Ad5 vectors were covalently modified with 5-, 20-, and 35-kDa linear PEG polymers and evaluated for their ability to produce immune responses against transgene antigen products and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by the …

The Human Immunodeficiency Virus Type 1 Envelope Confers Higher Rates Of Replicative Fitness To Perinatally Transmitted Viruses Than To Nontransmitted Viruses, Xiaohong Kong, John T. West, Hong Zhang, Danielle Shea, Tendai J. M'Soka, Charles Wood

Nebraska Center for Virology: Faculty Publications

Selection of a minor viral genotype during perinatal transmission of human Immunodeficiency virus type 1 (HIV-1) has been observed, but there is a lack of information on the correlation of the restrictive transmission with biological properties of the virus, such as replicative fitness. Recombinant viruses expressing the enhanced green fluorescent protein or the Discosoma sp. red fluorescent (DsRed2) protein carrying the V1 to V5 regions of env from seven mother-infant pairs (MIPs) infected by subtype C HIV-1 were constructed, and competition assays were carried out to compare the fitness between the transmitted and nontransmitted viruses. Flow cytometry was used to …

Neutralization-Sensitive R5 Shiv-2873nip Encoding Env From A Infant With Recent Hiv Clade C Infection, Nagadenahalli B. Siddappa, Ruijiang Song, Victor G. Kramer, Agnes-Laurence Chenine, Vijayakumar Velu, Helena Ong, Robert A. Rasmussen, Ricky D. Grisson, Charles Wood, Hong Zhang, Chipepo Kankasa, Rama Rao Amara, James G. Else, Francis J. Novembre, David Montefiori, Ruth M. Ruprecht

Nebraska Center for Virology: Faculty Publications

HIV-C (HIV-C) accounts for >56% of all HIV infections worldwide. To investigate vaccine safety and efficacy in non-human primates, a pathogenic, R5-tropic, neutralization sensitive simian-human immunodeficiency virus (SHIV) encoding HIV-C env would be desirable. We have constructed SHIV-2873Ni, an R5 SHIV encoding a primary pediatric HIV-C env isolated from a 2-month old Zambian infant, who progressed to death within one year of birth. SHIV-2873Ni was constructed using SHIV-1157ipd3N4 (Song et al., J. Viol. 80:8729-38, 2006) as backbone since the latter contains additional NF-κB sites in the long terminal repeats (LTRs) to enhance viral replicative capacity. The parental virus, SHIV-2873Ni, was …

Multidimensional Protein Fractionation Using Proteomelab Pf 2d™ For Profiling Amyotrophic Lateral Sclerosis Immunity: A Preliminary Report, Joshua Schlautman, Wojciech Rozek, Robert Stetler, R. Lee Mosley, Howard Gendelman, Pawel Ciborowski

Nebraska Center for Virology: Faculty Publications

Background: The ProteomeLab™ PF 2D platform is a relatively new approach to global protein profiling. Herein, it was used for investigation of plasma proteome changes in amyotrophic lateral sclerosis (ALS) patients before and during immunization with glatiramer acetate (GA) in a clinical trial.
Results: The experimental design included immunoaffinity depletion of 12 most abundant proteins from plasma samples with the ProteomeLab™ IgY-12 LC10 column kit as first dimension separation, also referred to as immuno-partitioning. Second and third dimension separations of the enriched proteome were performed on the PF 2D platform utilizing 2D isoelectric focusing and RP-HPLC with the resulting fractions …

Mortality Among Hiv-1- And Human Herpesvirus Type 8 – Affected Mother-Infant Pairs In Zambia, Janet Wojcicki, Mulindi Mwanahamuntu, Veenu Minhas, Boris Djokic, Chipepo Kankasa, Winslow Klaskala, Brad Brayfield, Saul Phiri, Charles Wood, Charles Mitchell

Nebraska Center for Virology: Faculty Publications

Objective: To determine the respective trends in mortality of Zambian mother-infant pairs based on maternal infection with HIV-1 and human herpesvirus type 8 (HHV-8).
Methods: A prospective cohort study was done on Zambian mother-infant pairs, stratified by maternal serologic status and followed from 6 weeks postdelivery for 48 months. Statistical analysis of the differences in the calculated mortality rates among the four groups was done using Stata 7.0. Kaplan-Meier analysis and Cox proportional hazard models were used to measure subject survival time.
Results: Between September 1998 and March 2002, a total of 1,425 mother-infant pairs were enrolled. …

Long-Term Persistence Of Mumps Antibody After Receipt Of 2 Measles-Mumps-Rubella (Mmr) Vaccinations And Antibody Response After A Third Mmr Vaccination Among A University Population, Anand Date, Moe H. Kyaw, Alison M. Rue, Julie Klahn, Leann Obrecht, Terry Krohn, Josh Rowland, Steve Ruben, Thomas J. Safranek, William J. Bellini, Gustavo H. Dayan

Nebraska Center for Virology: Faculty Publications

Background. High attack rates among vaccinated young adults reported during the 2006 mumps outbreak in the United States heightened concerns regarding mumps vaccine failure.

Methods. Serum specimens from university students and staff were tested for mumps immunoglobulin (Ig) G by enzyme immunoassay (EIA). A subset of participants vaccinated for ≤5 years and ≥15 years were tested by neutralizing antibody (NA) assay. Persons seronegative by EIA were offered a third dose of measles-mumps-rubella vaccine (MMR3), and serum specimens were obtained 7–10 days and 2–3 months after its administration.

Results. Overall, 94% (95% confidence interval [CI], 91%–96%) of the 440 participants were …

Analysis Of Cis-Elements That Facilitate Extrachromosomal Persistence Of Human Papillomavirus Genomes, Daraporn Pittayakhajonwut, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) are maintained latently in dividing epithelial cells as nuclear plasmids. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and stable plasmid maintenance in host cells. Recent experiments in yeast have demonstrated that viral genomes retain replication and maintenance function independently of E1 and E2 [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002). Stable replication of papillomavirus genomes in Saccharomyces cerevisiae. J. Virol. 76(7), 3350-8; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005). Identification of cis-acting elements that mediate the replication and maintenance of human …

Porcine Reproductive And Respiratory Syndrome Virus Infects Mature Porcine Dendritic Cells And Up-Regulates Interleukin-10 Production, Lilian Flores-Mendoza, Erika Silva-Campa, Monica Resendiz, Fernando A. Osorio, Jesus Hernandez

Nebraska Center for Virology: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) infects mature dendritic cells (mDCs) derived from porcine monocytes and matured with lipopolysaccharide. The infection of mDCs induced apoptosis, reduced the expression of CD80/86 and major histocompatibility complex class II molecules, and increased the expression of interleukin-10, thus suggesting that such mDC modulation results in the impairment of T-cell activation.

Kaposi’S Sarcoma-Associated Herpesvirus Transactivator Rta Promotes Degradation Of The Repressors To Regulateviral Lytic Replication, Zhilong Yang, Zhangcai Yan, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) RTA is an important protein involved in the induction of KSHV lytic replication from latency through activation of the lytic cascade. A number of cellular and viral proteins, including K-RBP, have been found to repress RTA-mediated transactivation and KSHV lytic replication. However, it is unclear as to how RTA overcomes the suppression during lytic reactivation. In this study, we found that RTA can induce K-RBP degradation through the ubiquitinproteasome pathway and that two regions in RTA are responsible. Moreover, we found that RTA can promote the degradation of several other RTA repressors. RTA mutants …

Chlorella Viruses Evoke A Rapid Release Of K+ From Host Cells During The Early Phase Of Infection, Monika Neupartl, Christine Meyer, Isabell Woll, Florian Frohns, Ming Kang, James L. Van Etten, Detlef Kramer, Brigitte Hertel, Anna Moroni, Gerhard Thiel

Nebraska Center for Virology: Faculty Publications

Infection of Chlorella NC64A cells by PBCV-1 produces a rapid depolarization of the host probably by incorporation of a viral-encoded K⁺ channel (Kcv) into the host membrane. To examine the effect of an elevated conductance, we monitored the virus-stimulated efflux of K⁺ from the Chlorella cells. The results indicate that all 8 Chlorella viruses tested evoked a host specific K⁺ efflux with a concomitant decrease in the intracellular K⁺. This K⁺ efflux is partially reduced by blockers of the Kcv channel. Qualitatively these results support the hypothesis that depolarization and K⁺ efflux are …

Mutual Inhibition Between Kaposi’S Sarcoma-Associated Herpesvirus And Epstein-Barr Virus Lytic Replication Initiators In Dually-Infected Primary Effusion Lymphoma, Yanjun Jiang, Dongsheng Xu, Yong Zhao, Luwen Zhang

Nebraska Center for Virology: Faculty Publications

Background: Both Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) are members of the human gamma herpesvirus family: each is associated with various human cancers. The majority of AIDS-associated primary effusion lymphoma (PEL) are co-infected with both KSHV and EBV. Dually-infected PELs selectively switch from latency to lytic replication of either KSHV or EBV in response to chemical stimuli. KSHV replication and transcription activator (K-RTA) is necessary and sufficient for the switch from KSHV latency to lytic replication, while EBV BZLF1 gene product (EBV-Z) is a critical initiator for induction of EBV lytic replication.

Methodology/Principal Findings: We show K-RTA and …

Hsp40 Facilitates Nuclear Import Of The Human Immunodeficiency Virus Type 2 Vpx-Mediated Preintegration Complex, Xiaogang Cheng, Michael Belshan, Lee Ratner

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 2 (HIV-2) Vpx is required for nuclear translocation of the viral preintegration complex (PIC) in quiescent cells. In order to decipher the mechanism of action of Vpx, a cDNA library was screened with the yeast two-hybrid assay, resulting in the identification of heat shock protein 40, Hsp40/DnaJB6, as a Vpx-interactive protein. Interaction with Vpx was confirmed by glutathione S-transferase (GST) pull-down and coimmunoprecipitation assays. Overexpression of Hsp40/DnaJB6 enhanced Vpx nuclear import, whereas overexpression of a nuclear localization mutant of Hsp40/DnaJB6 (H31Q) or down-regulation of Hsp40/DnaJB6 by small interfering RNA (siRNA) reduced the nuclear import of Vpx. …

Rapid Preclinical Detection Of Sheeppox Virus By A Real-Time Pcr Assay, C. A. Balinsky, Gustavo A. Delhon, G. Smoliga, M. Prarat, R. A. French, S. J. Geary, S. J. Geary, D. L. Rock, L. L. Rodriguez

Nebraska Center for Virology: Faculty Publications

Sheeppox virus (SPPV) is a member of the Capripoxvirus (CaPV) genus of the Poxviridae family. Members of this genus, which also include goatpox and lumpy skin disease viruses, cause economically significant disease in sheep, goats, and cattle. A rapid diagnostic assay for CaPV would be useful for disease surveillance as well as for detection of CaPV in clinical samples and for outbreak management. Here we describe a fluorogenic probe hydrolysis (TaqMan) PCR assay designed for rapid detection of CaPV and tested on sheep experimentally infected with a virulent strain of SPPV. This assay can detect SPPV in buffy coats, nasal …

Adaptation Of The Human Immunodeficiency Virus Type 1 Envelope Glycoproteins To New World Monkey Receptors, Beatriz Pacheco, Stephane Basmaciogullari, Jason A. Labonte, Shi-Hua Xiang, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) infection encounters an early block in the cells of New World monkeys because the CD4 receptor does not efficiently support HIV-1 entry. We adapted HIV-1(NL4-3) and HIV-1(KB9), two HIV-1 variants with different envelope glycoproteins, to replicate efficiently in cells expressing the CD4 and CXCR4 proteins of the common marmoset, a New World monkey. The HIV-1(NL4-3) adaptation involves three gp120 changes that result in a specific increase in affinity for the marmoset CD4 glycoprotein. The already high affinity of the HIV-1(KB9) envelope glycoproteins for marmoset CD4 did not significantly change as a result of the …

Genetic Variation In Mother-Child Acute Seroconverter Pairs From Zambia, Federico G. Hoffmann, Xiang He, John T. West, Philippe Lemey, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Objective: To characterize the envelope (env) glycoprotein of HIV-1 in mother-infant pairs (MIP) that underwent near simultaneous or acute-phase seroconversion, we examined the env sequence of the transmitted viruses and compare viral evolution within the pair.

Design: Three MIP from a Zambian cohort that seroconverted at the same sampling time were identified and followed longitudinally.

Methods: The V1-V5 region of the HIV-1 env gene was sequenced for each sample collected. Phylogenetic and population genetics analyses were carried out to subtype the viruses, estimate relationships among viral genotypes, and compare molecular evolution between the viral populations. …

A Versatile Assay For The Identification Of Rna Silencing Suppressors Based On Complementation Of Viral Movement, Jason G. Powers, Tim L. Sit, Feng Qu, T. Jack Morris, Kook-Hyung Kim, Steven A. Lommel

Nebraska Center for Virology: Faculty Publications

The cell-to-cell movement of Turnip crinkle virus (TCV) in Nicotiana benthamiana requires the presence of its coat protein (CP), a known suppressor of RNA silencing. RNA transcripts of a TCV construct containing a reporter gene (green fluorescent protein) (TCV-sGFP) in place of the CP open reading frame generated foci of three to five cells. TCV CP delivered in trans by Agrobacterium tumefaciens infiltration potentiated movement of TCV-sGFP and increased foci diameter, on average, by a factor of four. Deletion of the TCV movement proteins in TCV-sGFP (construct TCVΔ92-sGFP) abolished the movement complementation ability of TCV CP. Other known suppressors of …