Life Sciences Commons^™

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 …

Phylogeographical Structure And Evolutionary History Of Two Buggy Creek Virus Lineages In The Western Great Plains Of North America, Abinash Padhi, Amy T. Moore, Mary Bomberger Brown, Jerome E. Foster, Martin Pfeffer, Kathryn P. Gaines, Valerie A. O'Brien, Stephanie A. Strickler, Allison E. Johnson, Charles R. Brown

School of Natural Resources: Faculty Publications

Buggy Creek virus (BCRV) is an unusual arbovirus within the western equine encephalitis complex of alphaviruses. Associated with cimicid swallow bugs (Oeciacus vicarius) as its vector and the cliff swallow (Petrochelidon pyrrhonota) and house sparrow (Passer domesticus) as its amplifying hosts, this virus is found primarily in the western Great Plains of North America at spatially discrete swallow nesting colonies. For 342 isolates collected in Oklahoma, Nebraska, Colorado, and North Dakota, from 1974 to 2007, we sequenced a 2076 bp region of the 26S subgenomic RNA structural glycoprotein coding region, and analyzed phylogenetic relationships, …

Tissue And Stage-Specific Juvenile Hormone Esterase (Jhe) And Epoxide Hydrolase (Jheh) Enzyme Activities And Jhe Transcript Abundance In Lines Of The Cricket Gryllus Assimilis Artificially Selected For Plasma Jhe Activity: Implications For Jhe Microevolution, Anurag Anand, Erica Crone, Anthony J. Zera

Anthony Zera Publications

Fat body and midgut juvenile hormone esterase (JHE) and juvenile hormone epoxide hydrolase (JHEH) specific activities, and plasma JHE activity, were measured throughout the last stadium in two pairs (blocks) of lines of the cricket Gryllus assimilis, each pair of which had been artificially selected for high- or low-plasma JHE activity. Highly significant differences were observed between high- and low-activity lines of each block on most days for fat body JHE, and on one day for midgut JHE activity. In each block, line differences in developmental profiles for fat body JHE activity paralleled line differences in plasma JHE activity …

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 …

Candida Albicans Tup1 Is Involved In Farnesol-Mediated Inhibition Of Filamentous-Growth Induction, Bessie W. Kebaara, Melanie L. Langford, Dhammika H. M. L. P. Navarathna, Raluca Dumitru, Kenneth W. Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

Candida albicans is a dimorphic fungus that can interconvert between yeast and filamentous forms. Its ability to regulate morphogenesis is strongly correlated with virulence. Tup1, a transcriptional repressor, and the signaling molecule farnesol are both capable of negatively regulating the yeast to filamentous conversion. Based on this overlap in function, we tested the hypothesis that the cellular response to farnesol involves, in part, the activation of Tup1. Tup1 functions with the DNA binding proteins Nrg1 and Rfg1 as a transcription regulator to repress the expression of hypha-specific genes. The tup1/tup1 and nrg1/nrg1 mutants, but not the rfg1/rfg1 mutant, failed to …

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 …

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 …

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.

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 …

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 …

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. …

Evolutionary And Structural Analyses Of Alpha-Papillomavirus Capsid Proteins Yields Novel Insights Into L2 Structure And Interaction With L1, John Lowe, Debasis Panda, Suzanne Rose, Ty Jensen, Willie Hughes, For Yue Tso, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Background: PVs (PV) are small, non-enveloped, double-stranded DNA viruses that have been identified as the primary etiological agent for cervical cancer and their potential for malignant transformation in mucosal tissue has a large impact on public health. The PV family Papillomaviridae is organized into multiple genus based on sequential parsimony, host range, tissue tropism, and histology. We focused this analysis on the late gene products, major (L1) and minor (L2) capsid proteins from the family Papillomaviridae genus Alpha-papillomavirus. Alpha-PVs preferentially infect oral and anogenital mucosa of humans and primates with varied risk of oncogenic transformation. Development of evolutionary associations between …

The Viral Etiology Of Aids-Associated Malignancies, Peter C. Angeletti, Luwen Zhang, Charles Wood

Nebraska Center for Virology: Faculty Publications

The first documented cases of acquired immunodeficiency syndrome (AIDS) were characterized by the presence of rare Kaposi’s sarcoma (KS) skin lesions. More than 10 years later, it was discovered that the causative agent of KS was a γ-herpesvirus, human herpesvirus-8 (HHV-8) (KS-associated herpesvirus, KSHV). It is now abundantly clear that cancers induced by viral agents [such as, Epstein-Barr virus (EBV) and human papillomavirus (HPV)] are exacerbated by human immunodeficiency virus (HIV) infection and subsequent immune suppression. For example, the incidence of and primary central nervous system (CNS) lymphoma (PCNSL) and Hodgkin’s and high grade B-cell non-Hodgkin’s lymphomas (NHL), nasopharyngeal carcinoma …

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. …

Early Childhood Infection By Human Herpesvirus 8 In Zambia And The Role Of Human Immunodeficiency Virus Type 1 Coinfection In A Highly Endemic Area, Veenu Minhas, Kay L. Crabtree, Ann Chao, Tendai J. M'Sola, Chipepo Kankasa, Marc Bulterys, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma occurs at high incidence among Zambian adults and children, but there is a paucity of data on human herpesvirus 8 (HHV-8) incidence and routes of infection, especially in children. Between 1998 and 2004, the authors conducted a prospective study of viral transmission in a cohort of 684 children in Lusaka, Zambia, to estimate the annual incidence of HHV-8 from birth through 48 months of age. Maternal and pediatric human immunodeficiency virus type 1 (HIV-1) infection status was also determined. The results, based on 1,532 child-years of follow-up, showed that HHV-8 seroconversion occurs early in life. The incidence rate …

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 …

Modified Kigali Combined Staging Predicts Risk Of Mortality In Hiv-Infected Adults In Lusaka, Zambia, Philip J. Peters, Isaac Zulu, Nzali G. Kancheya, Shabir Lakhi, Elwyn Chomba, Cheswa Vwalika, Dhong-Jin Kim, Ilene Brill, Jareen Meinzen-Derr, Amanda Tichacek, Susan A. Allen

Nebraska Center for Virology: Faculty Publications

We assessed the utility of the modified Kigali combined (MKC) staging system for predicting survival in HIV-infected Zambian adults in a prospective, longitudinal, open cohort. From 1995 to 2004, HIV-discordant couples (one HIV-infected partner and one HIV-negative partner) were recruited from couples’ voluntary counseling and testing centers in Lusaka, Zambia and followed at 3-month intervals. MKC stage, which incorporates clinical stage with erythrocyte sedimentation rate (ESR), hematocrit, and body mass index (BMI), was determined at enrollment. Kaplan–Meier survival and Cox proportional hazard methods were used to calculate median survival and relative hazards. We enrolled 1479 HIV-discordant couples with a combined …

Development Of An Immunofluorescence Assay Using Recombinant Proteins Expressed In Insect Cells To Screen And Confirm Presence Of Human Herpesvirus 8-Specific Antibodies, Veenu Minhas, Lynsey N. Crosby, Kay L. Crabtree, Saul Phiri, Tendai J. M'Soka, Chipepo Kankasa, William J. Harrington, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 8 (HHV-8), or Kaposi’s sarcoma (KS)-associated herpesvirus, has been linked to all forms of KS. The results of most current serological assays for the detection of HHV-8-specific antibodies have low levels of concordance among themselves. To establish a sensitive and specific testing strategy that can be used to screen for HHV-8-specific antibodies, three HHV-8 proteins, ORF65, ORF73, and K8.1A, were expressed by using baculoviral vectors in insect cells and incorporated into a monoclonal antibodyenhanced immunofluorescence assay (mIFA) termed the Sf9 three-antigen mIFA. The results obtained by this mIFA were compared to those obtained by a standard mIFA with …

Experimental Inoculation Of House Sparrows (Passer Domesticus) With Buggy Creek Virus, Kathryn P. Huyvaert, Amy T. Moore, Nicholas A. Panella, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

We performed experimental inoculations of house sparrows (Passer domesticus) with Buggy Creek virus (BCRV), a poorly known alphavirus (Togaviridae) vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) that is an ectoparasite of the cliff swallow (Petrochelidon pyrrhonota) and house sparrow. Viremias were detected by plaque assay in two of six birds on days 1–3 postinoculation; viremia was highest on day 2. Viral RNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in blood of six of 12 birds ranging from day 1 to day 15 postinoculation. Infectious BCRV was detected in …

Small-Molecule Cd4 Mimics Interact With A Highly Conserved Pocket On Hiv-1 Gp120, Navid Madani, Arne Schön, Amy M. Princiotto, Judith M. Lalonde, Joel R. Cpurter, Takahiro Soeta, Danny Ng, Liping Wang, Evan T. Brower, Shi-Hua Xiang, Young Do Kwon, Chih-Chin Huang, Richard Wyatt, Peter D. Kwong, Ernesto Freire, Amos B. Smith Iii, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus (HIV-1) interaction with the primary receptor, CD4, induces conformational changes in the viral envelope glycoproteins that allow binding to the CCR5 second receptor and virus entry into the host cell. The small molecule NBD-556 mimics CD4 by binding the gp120 exterior envelope glycoprotein, moderately inhibiting virus entry into CD4-expressing target cells, and enhancing CCR5 binding and virus entry into CCR5-expressing cells lacking CD4. Studies of NBD-556 analogues and gp120 mutants suggest that: 1) NBD-556 binds within the Phe 43 cavity, a highly conserved, functionally important pocket formed as gp120 assumes the CD4- bound conformation; 2) the NBD-556 …

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 M. 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 …

Varying Efficiency Of Long-Term Replication Of Papillomaviruses In Saccharomyces Cerevisiae, Adam J. Rogers, Malte Loggen, Karen Lee, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) replicate in mitotically active basal keratinocytes. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and maintenance of HPV episomes. We previously showed that HPV16 could replicate stably in Saccharomyces cerevisiae [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002)] and we identified cis-elements that mediate replication and maintenance [J. Virol. 76(7), 3350-3358.; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005)]. Here, we demonstrate that although multiple HPV genomes replicate stably in yeast, they do so with differing long-term efficiency; HPV6-Ura3 is replicated at the …

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 …

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 prod- ucts and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by …