Virology Commons^™

A Novel Codon-Optimized Siv Gag-Pol Immunogen For Genebased Vaccination, Catherine M. Crosby, Eric A. Weaver, Reeti Khare, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Simian immunodeficiency virus (SIV) is a robust pathogen used in non-human primates to model HIV vaccines. SIV encodes a number of potential vaccine targets. By far the largest and most conserved protein target in SIV is its gag-pol protein that bears many epitopes to drive multivalent immune T cell responses. While gag-pol is an attractive antigen, it is only translated after a frame shift between gag and pol with the effect that gag and pol are expressed at an approximate 10/1 ratio. The codon bias of native lentiviral genes are also mismatched with the abundance of tRNAs in mammalian cells …

Whole-Genome Sequencing Of Kaposi’S Sarcoma-Associated Herpesvirus From Zambian Kaposi’S Sarcoma Biopsy Specimens Reveals Unique Viral Diversity, Landon Olp, Adrien Jeanniard, Clemence Marimo, Charles Wood

Nebraska Center for Virology: Faculty Publications

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent for Kaposi’s sarcoma (KS). Both KSHV and KS are endemic in sub-Saharan Africa where approximately 84% of global KS cases occur. Nevertheless, whole-genome sequencing of KSHV has only been completed using isolates from Western countries—where KS is not endemic. The lack of whole-genome KSHV sequence data from the most clinically important geographical region, sub-Saharan Africa, represents an important gap since it remains unclear whether genomic diversity has a role on KSHV pathogenesis. We hypothesized that distinct KSHV genotypes might be present in sub-Saharan Africa compared to Western countries. Using a KSHV-targeted enrichment …

The Hippo/Yap Pathway Interacts With Egfr Signaling And Hpv Oncoproteins To Regulate Cervical Cancer Progression, Chunbo He, Dagan Mao, Guohua Hua, Xiangmin Lv, Xingcheng Chen, Peter C. Angeletti, Jixin Dong, Steven W. Remmenga, Kerry J. Rodabaugh, Jin Zhou, Paul F. Lambert, Peixin Yang, John S. Davis, Cheng Wang

Nebraska Center for Virology: Faculty Publications

The Hippo signaling pathway controls organ size and tumorigenesis

through a kinase cascade that inactivates Yes-associated

protein (YAP). Here, we show that YAP plays a central role in

controlling the progression of cervical cancer. Our results suggest

that YAP expression is associated with a poor prognosis for cervical

cancer. TGF-α and amphiregulin (AREG), via EGFR, inhibit the Hippo

signaling pathway and activate YAP to induce cervical cancer cell

proliferation and migration. Activated YAP allows for up-regulation

of TGF-α, AREG, and EGFR, forming a positive signaling loop to

drive cervical cancer cell proliferation. HPV E6 protein, a major

etiological molecule of …

Observed And Expected Incidence Of Cervical Cancer In Lusaka And The Southern And Western Provinces Of Zambia, 2007 - 2012, Mulele Kalima, Kennedy Lishimpi, Jane L. Meza, Shinobu Watanabe-Galloway, Susan C. Msadabwe, Catherine K. Mwaba, Aaron L. Shibemba, Lewis Banda, Charles Wood, Robert M. Chamberlain, Amr S. Soliman

Nebraska Center for Virology: Faculty Publications

Objectives—Cervical cancer is increasing but underestimated in developing countries. We calculated the observed and expected incidence of cervical cancer in Lusaka and Southern and Western provinces of Zambia.

Methods/Materials—Data for 2007-2012 was obtained for the 3 provinces. Data included age, residence, year of diagnosis, marital status, occupation, HIV, stage, radiotherapy and chemotherapy. Expected incidence in Southern and Western provinces was calculated based on observed incidence for Lusaka province, adjusting for HIV.

Results—Crude and age-standardized incidence rates (ASR) in Lusaka were 2-4 times higher than incidence in the other 2 provinces. Lusaka had a rate of 54.1/10⁵ and ASR of …

Crf07_Bc Strain Dominates The Hiv-1 Epidemic In Injection Drug Users In Liangshan Prefecture Of Sichuan, China, Lin Li, Daying Wei, Wan-Ling Hsu, Tianyi Li, Tao Gui, Charles Wood, Yongjian Liu, Hanping Li, Zuoyi Bao, Siyang Liu, Xiaolin Wang, Jingyun Li

Nebraska Center for Virology: Faculty Publications

The Liangshan prefecture in Sichuan province is an area in China severely affected by the HIV epidemic, with intravenous drug use (IDU) as the main risk factor. No reports on HIV subtypes prevalent in IDUs in Liangshan prefecture could be found. In this study, we have characterized the genotypes of HIV-1 in the IDU population in Liangshan prefecture and further determined the phylogenetic relationship of the CRF07_BC strains to HIV-1 sequences from the other regions of China, including Xinjiang and Yunnan provinces, to explore the pattern and possible diffusion pathway of HIV-1 in these regions. HIV-1-seropositive drug-naive IDUs identified in …

Single-Dose Cpg Immunization Protects Against A Heterosubtypic Challenge And Generates Antigen-Specific Memory T Cells, Alexander J. Vogel, Deborah M. Brown

Nebraska Center for Virology: Faculty Publications

Despite extensive research, influenza A virus (IAV) remains a major cause of morbidity, mortality, and healthcare expenditure. Emerging pandemics from highly pathogenic IAV strains, such as H5N1 and pandemic H1N1, highlight the need for universal, crossprotective vaccines. Current vaccine formulations generate strain-specific neutralizing antibodies primarily against the outer coat proteins, hemagglutinin and neuraminidase. In contrast to these highly mutable proteins, internal proteins of IAV are more conserved and are a favorable target for developing vaccines that induce strong T cell responses in addition to humoral immunity. Here, we found that intranasal administration with a single dose of CpG and inactivated …

Imaging Luciferase-Expressing Viruses, Michael A. Barry, Shannon May, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Optical imaging of luciferage gene expression has become a powerful tool to track cells and viruses in vivo in small animal models. Luciferase imaging has been used to study the location of infection by replication-defective and replication-competent viruses and to track changes in the distribution of viruses in mouse models. This approach has also been used in oncolytic studies as a non-invasive means to monitor the growth and killing of tumor cells modified with luciferase genes. In this chapter, we describe the techniques used for luciferase imaging as have been applied to track replication-defective and replication-competent adenoviruses in mouse and …

Chlorovirus Skp1 And Core Ankyrin-Repeat Protein Interplay And Mimicry Of Cellular Ubiquitin Ligase Machinery, Eric Andrew Noel

School of Biological Sciences: Dissertations, Theses, and Student Research

The ubiquitin-proteasome system is a common target of several unrelated viruses that have evolved convergent strategies to redirect host ubiquitin machinery to serve their own needs. Members of the genus Chlorovirus, a group of large dsDNA viruses that infect certain freshwater chlorella-like green algae, encode a conserved Skp1 homolog and ankyrin-repeat (ANK) proteins, some of which contain C-terminal domains characteristic of cellular F-boxes or related viral PRANC domains. These observations suggested that this unique combination of chlorovirus proteins either interact with or imitate the key components of the SCF (Skp1-Cul1-F-box) ubiquitin ligases. Using mass spectrometry, we identified two functional …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

Genome-Wide Analysis Of The Variation In Host Genetics In Response To Experimental Challenges With Porcine Circovirus 2b, Taylor B. Engle

Department of Animal Science: Dissertations, Theses, and Student Research

Porcine circovirus is the primary causative agent responsible for inducing a group of associated diseases known as porcine circovirus associated diseases (PCVAD), which can have detrimental effects on production efficiency as well as lead to mortality. The variation in host genetics plays a role in the ability to initiate an effective immune response. The objective of this research was to identify major genetic variants and genes that influence immune response and PCVAD susceptibility. Commercial crossbred pigs (n=974) were experimentally infected with a PCV2b strain to analyze genetic sources of variation in PCVAD susceptibility. The strain used for experimental infection was …

Cd46-Mediated Transduction Of A Species D Adenovirus Vaccine Improves Mucosal Vaccine Efficacy, Zenaido T. Camacho, Michael A. Barry, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

The high levels of preexisting immunity against Adenovirus type 5 (Ad5) have deemed Ad5 unusable for translation as a human vaccine vector. Low seroprevalent alternative viral vectors may be less impacted by preexisting immunity, but they may also have significantly different phenotypes from that of Ad5. In this study we compare species D Ads (26, 28, and 48) to the species C Ad5. In vitro transduction studies show striking differences between the species C and D viruses. Most notably, Ad26 transduced human dendritic cells much more effectively than Ad5. In vivo imaging studies showed strikingly different transgene expression profiles. The …

Vaccines Within Vaccines: The Use Of Adenovirus Types 4 And 7 As Influenza Vaccine Vectors, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

Adenovirus Types 4 and 7 (Ad4 and Ad7) are associated with acute respiratory distress (ARD). In order to prevent widespread Ad-associated ARD (Ad-ARD) the United States military immunizes new recruits using a safe and effective lyophilized wildtype Ad4 and Ad7 delivered orally in an enteric-coated capsule. We cloned Ad4 and Ad7 and modified them to express either a GFP-Luciferase (GFPLuc) fusion gene or a centralized influenza H1 hemagglutinin (HA1-con). BALB/c mice were injected with GFPLuc expressing viruses intramuscularly (i.m.) and intranasally (i.n.). Ad4 induced significantly higher luciferase expression levels as compared with Ad7 by both routes. Ad7 transduction was restored …

Deep Rna Sequencing Reveals Hidden Features And Dynamics Of Early Gene Transcription In Paramecium Bursaria Chlorella Virus 1, Guillaume Blanc, Michael Mozar, Irina V. Agarkova, James R. Gurnon, Giane Yanai-Balser, Janet M. Rowe, Yuannan Xia, Jean-Jack Riethoven, David D. Dunigan, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of the genus Chlorovirus (family Phycodnaviridae) that infects the unicellular, eukaryotic green alga Chlorella variabilis NC64A. The 331-kb PBCV-1 genome contains 416 major open reading frames. A mRNA-seq approach was used to analyze PBCV-1 transcriptomes at 6 progressive times during the first hour of infection. The alignment of 17 million reads to the PBCV-1 genome allowed the construction of single-base transcriptome maps. Significant transcription was detected for a subset of 50 viral genes as soon as 7 min after infection. By 20 min post infection (p.i.), transcripts were detected for …

Functional Implications Of The Baf–B1 Axis During The Vaccinia Virus Life Cycle, Nouhou Ibrahim

School of Biological Sciences: Dissertations, Theses, and Student Research

Vaccinia virus is the prototypic member of the Poxviridae family, which includes variola virus, the agent of smallpox. Poxviruses encode their own transcriptional machinery and a set of proteins to evade the host defense system, and thus are able to replicate entirely in the cytoplasm of their host. The poxvirus life cycle occurs in sequential stages: early gene expression, DNA replication, intermediate gene expression and then late gene expression and morphogenesis. The temporally staged poxvirus life cycle makes viral DNA replication a required event for post-replicative events to occur. However, viral DNA replication itself depends on an early viral Ser/Thr …

Inflammation Enhances Il-2 Driven Differentiation Of Cytolytic Cd4 T Cells, Aspen M. Workman, Ashley K. Jacobs, Alexander J. Vogel, Shirley Condon, Deborah M. Brown

Nebraska Center for Virology: Faculty Publications

Cytolytic CD4 T cells (CD4 CTL) have been identified in vivo in response to viral infections; however, the factors necessary for driving the cytolytic phenotype have not been fully elucidated. Our previously published work suggests IL-2 may be the master regulator of perforin-mediated cytotoxicity in CD4 effectors. To further dissect the role of IL-2 in CD4 CTL generation, T cell receptor transgenic mice deficient in the ability to produce IL-2 or the high affinity IL-2 receptor (IL-2Rα, CD25) were used. Increasing concentrations of IL-2 were necessary to drive perforin (Prf) expression and maximal cytotoxicity. Granzyme B (GrB) expression and killing …

Review Of Epidemiology And Transmission Of Kaposi’S Sarcoma-Associated Herpesvirus, Veenu Minhas, Charles Wood

Nebraska Center for Virology: Faculty Publications

This review summarizes the current knowledge pertaining to Kaposi sarcoma-associated herpesvirus (KSHV) epidemiology and transmission. Since the identification of KSHV twenty years ago, it is now known to be associated with Kaposi’s sarcoma (KS), primary effusion lymphoma, and multicentric Castleman’s disease. Many studies have been conducted to understand its epidemiology and pathogenesis and their results clearly show that the worldwide distribution of KSHV is uneven. Some geographical areas, such as sub-Saharan Africa, the Mediterranean region and the Xinjiang region of China, are endemic areas, but Western Europe and United States have a low prevalence in the general population. This makes …

High Prevalence Of Early Childhood Infection By Kshv In A Minority Population In China, Yifei Cao, Veenu Minhas, Xiaohua Tan, Jin Huang, Baodong Wang, Meiyi Zhu, Yuan Gao, Tingting Zhao, Lei Yang, Charles Wood

Nebraska Center for Virology: Faculty Publications

In China, KSHV seroprevalence varies considerably among different regions and ethnicities. But in Xinjiang province, located in the northwestern China, there is a very high seroprevalence of KSHV in adults of Kazak and Ughur ethnicities. However, KSHV prevalence in children and the risk factors associated with the acquisition of infection are currently not known. The aim of this study was to investigate the prevalence of KSHV infection, identify associated socio-economic or behavioral risk factors and the humoral immune response among children in this population. This is a cross-sectional study (N=178) to screen children and their caregivers from Xinjiang for total …

Seroprevalence Of Human Herpesvirus 8 And Hepatitis C Virus Among Drug Users In Shanghai, China, Tiejun Zhang, Ying Liu, Yuyan Zhang, Jun Wang, Veenu Minhas, Charles Wood, Na He

Nebraska Center for Virology: Faculty Publications

To elucidate and compare the seroprevalence of human herpesvirus 8 (HHV8) and hepatitis C virus (HCV) among Chinese drug users, a cross-sectional study of 441 participants, was conducted in Shanghai, China, from 2012 through 2013. Seventy-seven (17.5%) participants were found to be positive for HHV8 antibodies, while 271 (61.5%) participants were positive for HCV. No significant association between HHV8 seropositivity and drug use characteristics, sexual behaviors, HCV, or syphilis was observed. In contrast, a statistically significant association between HCV seropositivity and injected drug history (OR, 2.18, 95% CI 1.41–3.37) was detected, whereas no statistically significant association between HCV seropositivity and …

Global Analysis Of Chlorella Variabilis Nc64a Mrna Profiles During The Early Phase Of Paramecium Bursaria Chlorella Virus-1 Infection, Janet M. Rowe, Adrien Jeanniard, James R. Gurnon, Yuannan Xia, David D. Dunigan, James L. Van Etten, Guillaume Blanc

Nebraska Center for Virology: Faculty Publications

The PBCV-1/Chlorella variabilis NC64A system is a model for studies on interactions between viruses and algae. Here we present the first global analyses of algal host transcripts during the early stages of infection, prior to virus replication. During the course of the experiment stretching over 1 hour, about a third of the host genes displayed significant changes in normalized mRNA abundance that either increased or decreased compared to uninfected levels. The population of genes with significant transcriptional changes gradually increased until stabilizing at 40 minutes post infection. Functional categories including cytoplasmic ribosomal proteins, jasmonic acid biosynthesis and anaphase promoting …

Dynamic Attachment Of Chlorovirus Pbcv-1 To Chlorella Variabilis, Irina Agarkova, Brigitte Hertel, Xinzheng Zhang, Les Lane, Alexander Tchourbanov, David D. Dunigan, Gerhard Thiel, Michael G. Rossmann, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Chloroviruses infect their hosts by specifically binding to and degrading the cell wall of their algal hosts at the site of attachment, using an intrinsic digesting enzyme(s). Chlorovirus PBCV-1 stored as a lysate survived longer than virus alone, suggesting virus attachment to cellular debris may be reversible. Ghost cells (algal cells extracted with methanol) were used as a model to study reversibility of PBCV-1 attachment because ghost cells are as susceptible to attachment and wall digestion as are live cells. Reversibility of attachment to ghost cells was examined by releasing attached virions with a cell wall degrading enzyme extract. The …

Genetic Variation And Possible Mechanisms Driving The Evolution Of Worldwide Fig Mosaic Virus Isolates, Jeewan Jyot Walia, Anouk Willemsen, Eminur Elci, Kadriye Caglayan, Bryce W. Falk, Luis Rubio

Nebraska Center for Virology: Faculty Publications

Fig mosaic virus (FMV) is a multipartite negative-sense RNA virus infecting fig trees worldwide. FMV is transmitted by vegetative propagation and grafting of plant materials, and by the eriophyid mite Aceria ficus. In this work, the genetic variation and evolutionary mechanisms shaping FMV populations were characterized. Nucleotide sequences from four genomic regions (each within the genomic RNAs 1, 2, 3, and 4) from FMV isolates from different countries were determined and analyzed. FMV genetic variation was low, as is seen for many other plant viruses. Phylogenetic analysis showed some geographically distant FMV isolates which clustered together, suggesting long-distance migration. …

Live Siv Vaccine Correlate Of Protection: Immune Complex-Inhibitory Fc Receptor Interactions That Reduce Target Cell Availability, Anthony J. Smith, Stephen W. Wietgrefe, Liang Shang, Cavan S. Reilly, Peter J. Southern, Katherine E. Perkey, Lijie Duan, Heinz Kohler, Sybille Muller, James Robinson, John V. Carlis, Qingsheng Li, R. Paul Johnson, Ashley T. Haase

Nebraska Center for Virology: Faculty Publications

Principles to guide design of an effective vaccine against HIV are greatly needed, particularly to

protect women in the pandemic’s epicentre in Africa. We have been seeking these principles by

identifying correlates of the robust protection associated with SIV_mac239Δnef vaccination in the

SIV-rhesus macaque animal model of HIV-1 transmission to women. We have identified one

correlate of SIV_mac239Δnef protection against vaginal challenge as a resident mucosal system for

SIV-gp41 trimer antibody production and neonatal Fc receptor (FcRn)-mediated concentration of

these antibodies on the path of virus entry to inhibit establishment of infected founder populations

at the …

Risk Factors For Early Childhood Infection Of Human Herpesvirus-8 In Zambian Children: The Role Of Early Childhood Feeding Practices, Kay L. Crabtree, Janet M. Wojcicki, Veenu Minhas, David R. Smith, Chipepo Kankasa, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Background—Human herpesvirus-8 (HHV-8) infection in early childhood is common throughout sub-Saharan Africa with prevalence increasing throughout childhood. Specific routes of transmission have not been clearly delineated, though HHV-8 is present in high concentrations in saliva.

Methods—To understand the horizontal transmission of HHV-8 within households to children we enrolled for cross-sectional analysis, 251 households including 254 children, age two and under, in Lusaka, Zambia. For all children, plasma was screened for HHV-8 and HIV-1 and health and behavioral questionnaires were completed. Multi-level logistic regression analysis was conducted to assess independent factors for HHV-8 infection in children.

Results—Risk factors for HHV-8 infection …

Turnip Crinkle Virus Coat Protein Inhibits The Basal Immune Response To Virus Invasion In Arabidopsis By Binding To The Nac Transcription Factor Tip, Teresa Donze, Feng Qu, Paul Twigg, T. Jack Morris

Nebraska Center for Virology: Faculty Publications

Turnip crinkle virus (TCV) has been shown to interact with a NAC transcription factor, TIP, of Arabidopsis thaliana, via its coat protein (CP). This interaction correlates with the resistance response manifested in TCV-resistant Arabidopsis ecotype Di-17. We report that failure of a mutated CP to interact with TIP triggered the corresponding TCV mutant (R6A) to cause more severe symptoms in the TCV-susceptible ecotype Col-0. We hypothesized that TCV regulates antiviral basal immunity through TIP-CP interaction. Consistent with this hypothesis, we found that the rate of accumulation of R6A was measurably slower than wild-type TCV over the course of an …

Vaccines Within Vaccines: The Use Of Adenovirus Types 4 And 7 As Influenza Vaccine Vectors, Eric A. Weaver

Nebraska Center for Virology: Faculty Publications

adenovirus Types 4 and 7 (ad4 and ad7) are associated with acute respiratory distress (aRD). In order to prevent wide- spread ad-associated aRD (ad-aRD) the United states military immunizes new recruits using a safe and effective lyophi- lized wildtype ad4 and ad7 delivered orally in an enteric-coated capsule. We cloned ad4 and ad7 and modified them to express either a GFP-Luciferase (GFPLuc) fusion gene or a centralized influenza H1 hemagglutinin (Ha1-con). BaLB/c mice were injected with GFPLuc expressing viruses intramuscularly (i.m.) and intranasally (i.n.). ad4 induced significantly higher luciferase expression levels as compared with ad7 by both routes. ad7 transduction …

Construction Of A Live-Attenuated Hiv-1 Vaccine Through Genetic Code Expansion, Nanxi Wang, Yue Li, Wei Niu, Ming Sun, Ronald Cerny, Qingsheng Li, Jiantao Guo

Qingsheng Li Publications

A safe and effective vaccine against human immunodeficiency virus type 1 (HIV-1) is urgently needed to combat the worldwide AIDS pandemic, but still remains elusive. The fact that uncontrolled replication of an attenuated vaccine can lead to regaining of its virulence creates safety concerns precluding many vaccines from clinical application. We introduce a novel approach to control HIV-1 replication, which entails the manipulation of essential HIV-1 protein biosynthesis through unnatural amino acid (UAA*)-mediated suppression of genome-encoded blank codon. We successfully demonstrate that HIV-1 replication can be precisely turned on and off in vitro.

Includes supporting information.

Cell- And Virus-Mediated Regulation Of The Barrier-To-Autointegration Factor’S Phosphorylation State Controls Its Dna Binding, Dimerization, Subcellular Localization, And Antipoxviral Activity, Augusta Jamin, April Wicklund, Matthew S. Wiebe

Nebraska Center for Virology: Faculty Publications

Barrier-to-autointegration factor (BAF) is a DNA binding protein with multiple cellular functions, including the ability to act as a potent defense against vaccinia virus infection. This antiviral function involves BAF’s ability to condense double-stranded DNA and subsequently prevent viral DNA replication. In recent years, it has become increasingly evident that dynamic phosphorylation involving the vaccinia virus B1 kinase and cellular enzymes is likely a key regulator of multiple BAF functions; however, the precise mechanisms are poorly understood. Here we analyzed how phosphorylation impacts BAF’s DNA binding, subcellular localization, dimerization, and antipoxviral activity through the characterization of BAF phosphomimetic and unphosphorylatable …

Characterization Of A Dual-Tropic Human Immunodeficiency Virus (Hiv-1) Strain Derived From The Prototypical X4 Isolate Hxbc2, Shi-Hua Xiang, Beatriz Pacheco, Dane Bowder, Wen Yuan, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) coreceptor usage and tropism can be modulated by the V3 loop sequence of the gp120 exterior envelope glycoprotein. For coreceptors, R5 viruses use CCR5, X4 viruses use CXCR4, and dual-tropic (R5X4) viruses use either CCR5 or CXCR4. To understand the requirements for dual tropism, we derived and analyzed a dual-tropic variant of an X4 virus. Changes in the V3 base, which allow gp120 to interact with the tyrosine-sulfated CCR5 N-terminus, and deletion of residues 310/311 in the V3 tip were necessary for efficient CCR5 binding and utilization. Thus, both sets of V3 changes allowed …

Impact Of Wheat Streak Mosaic Virus And Triticum Mosaic Virus On Transmission By Aceria Tosichella Keifer (Eriophyidae) And Virus Epidemiology In Wheat, Camila F. De Oliveira

Department of Entomology: Dissertations, Theses, and Student Research

The wheat curl mite (WCM), Aceria tosichella Keifer, transmits a complex of viruses, Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV) and Wheat mosaic virus (WMoV), to wheat, Triticum aestivum, in the Great Plains. Co-infection of wheat by these viruses is frequently observed, increasing disease severity and yield loss.

Current genetic work classifies WCM populations into two genotypes, Type 1 and Type 2. It has been shown that different mite genotypes are able to transmit viruses at varying rates. WCM-virus relations are very specific and can impact vector biology. In this study, the primary objective was to determine …

Barrier To Autointegration Factor (Baf) Inhibits Vaccinia Virus Intermediate Transcription In The Absence Of The Viral B1 Kinase, Nouhou Ibrahim, April Wicklund, Augusta Jamin, Matthew S. Wiebe

Nebraska Center for Virology: Faculty Publications

Barrier to autointegration factor (BAF/BANF1) is a cellular DNA-binding protein found in the nucleus and cytoplasm. Cytoplasmic BAF binds to foreign DNA and can act as a defense against vaccinia DNA replication. To evade BAF, vaccinia expresses the B1 kinase, which phosphorylates BAF and blocks its ability to bind DNA. Interestingly, B1 is also needed for viral intermediate gene expression via an unknown mechanism. Therefore, we evaluated the impact of B1-BAF signaling on vaccinia transcription. Strikingly, the decrease in vaccinia transcription caused by loss of B1 can be rescued by depletion of BAF. The repressive action of BAF is greatest …