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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 Dec 2013

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 …


Do Bacterial And Fungal Communities In Soils Of The Bolivian Altiplano Change Under Shorter Fallow Periods?, L. Gomez-Montano, A. Jumpponen, M. A. Gonzales, J. Cusicanqui, C. Valdivia, P. P. Motavalli, M. Herman, K. A. Garrett Oct 2013

Do Bacterial And Fungal Communities In Soils Of The Bolivian Altiplano Change Under Shorter Fallow Periods?, L. Gomez-Montano, A. Jumpponen, M. A. Gonzales, J. Cusicanqui, C. Valdivia, P. P. Motavalli, M. Herman, K. A. Garrett

School of Biological Sciences: Faculty Publications

Traditional fallow periods in the Bolivian highlands are being shortened in an effort to increase short-term crop yields, with potential long-term impacts on soil microbial communities and their functions. In addition, native vegetation, such as Parasthrephia sp. or Baccharis sp. (both locally known as “thola”) are often removed as a fuel for cooking. We evaluated the effects of fallow period and thola on soils in 29 farmers’ fields in two municipalities in the Bolivian Altiplano (Umala and Ancoraimes). Soil fungal and bacterial community responses were characterized using 454-pyrosequencing. Soils in Ancoraimes had significantly higher levels of organic matter, nitrogen, and …


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 Sep 2013

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 …


Coccidia Of Gerbils From Mongolia, Ethan T. Jensen Aug 2013

Coccidia Of Gerbils From Mongolia, Ethan T. Jensen

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

In this study, gerbils collected in the Mongolia over the summers of 2009-2012 were examined for coccidia. In total, 171 gerbils of three species from 22 localities were examined for coccidia. Coccidian oocysts were identified from 21 gerbils, but those found in 1 of those gerbils were probably pseudoparasites of the host from which they were recovered. From the remaining 20 gerbils, 7 morphotypes of Eimeria and 1 morphotype of Isospora were identified. Four of the 7 morphotypes of Eimeria were attributed to new species which were described in this study. In addition, 10 previously described species of Eimeria were …


Analysis Of Human Papillomavirus Capsid Proteins: Insights Into Capsid Assembly, Willie A. Hughes Aug 2013

Analysis Of Human Papillomavirus Capsid Proteins: Insights Into Capsid Assembly, Willie A. Hughes

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

Abstract:

Papillomaviruses (PVs) are double stranded (ds)-DNA viruses (~8-kbp), which infect mucosal and cutaneous epithelial cells from various mammalian species, causing tumors in both epithelial cell-types. During the late-phase, the capsid proteins (L1 and L2), are expressed to encapsidate the viral genome generating infectious virion particles required for PV. Natural PV infections produce morphologically homogenous progeny virions 55-nm in diameter. Transient transfection systems allow individual expression of the capsid proteins, which are able to produce low-levels of infectious virion-like particles (VLPs) and non-infectious VLPs that have the capacity to resemble and function as wild-type virions.

Results: The research herein …


Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz Jul 2013

Characterization Of The Gut Microbiota And Colitogenic Bacterial Species In Core 1 O-Glycans Deficient Mice, Maria E. Perez-Munoz

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Mucus is one important component of the intestinal mucosal barrier, and loss of its functionality is associated with colitis in humans and mice. Mice deficient in core 1 O-glycans (TM-IEC C1galt1-/-) display a thinner mucus layer upon mutation of the glycosyltransferase enzyme (C1GALT1) responsible for core 1 O-glycans attachment, thus constituting an experimental model for human Ulcerative Colitis (UC). Under conventional conditions, these mice experience spontaneous inflammation of the colon. However, the exact role of the microbiota in colitis development in these mice has not been systematically investigated.

Aimed to gain insights into the role of …


Evolution Of Human Immunodeficiency Virus Type 1 Clade C Envelope V1-V5 Region During Disease Progression In Non-Human Primate Model, For Yue Tso May 2013

Evolution Of Human Immunodeficiency Virus Type 1 Clade C Envelope V1-V5 Region During Disease Progression In Non-Human Primate Model, For Yue Tso

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

Human immunodeficiency virus type 1 (HIV-1) clade C strain is the fastest spreading HIV-1 strain globally, especially in Africa. It has been decades since the acquired immune deficiency syndrome (AIDS) pandemic first started. However, an effective anti-HIV-1 vaccine is not yet available, which is partly due to the highly variable nature of HIV-1 envelope gene and the absence of a suitable animal model. Strengthening of the understanding of envelope evolution during disease progression will contribute significantly towards future anti-HIV-1 treatment and preventions.
Non-human primates have been an essential animal model for many biomedical research areas. Using simian-human immunodeficiency virus (SHIV) …


Validation Of Microwave Heating Instructions For The Destruction Of Salmonella Spp. In Microwaveable Foods, Carol J. Valenzuela Apr 2013

Validation Of Microwave Heating Instructions For The Destruction Of Salmonella Spp. In Microwaveable Foods, Carol J. Valenzuela

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Microwave heating instructions for three products (chicken nuggets, turkey pot-pies and mashed potato) were developed and validated based on end point temperatures using two microwave ovens (2,459 MHz; 700 W and 1,350 W). Heating instructions for chicken nuggets were validated using different configuration of product placement (edge or center of the carousel) and number of units (4, 6 and 8). Salmonella spp. reductions of 6.56 log CFU/g (700 W) were observed in chicken nuggets heated in groups of 4 and placed at the center of the carousel with 1 min 26 s of heating time with a target end point …


Telomere-Related Factors And Human Papillomavirus Genome Maintenance, Adam Rogers Apr 2013

Telomere-Related Factors And Human Papillomavirus Genome Maintenance, Adam Rogers

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

Human papillomaviruses (HPVs) are small DNA tumor viruses identified by their characteristic ability to replicate as a nuclear plasmid in mitotically active basal keratinocytes. A key characteristic of the HPV life cycle is the establishment of a stable maintenance phase wherein the virus replicates at low copy number, which likely occurs in cells expressing little to no E1 and E2. It is thought that HPV16 replicates in a once-per-cell-cycle manner during this portion of its life cycle and presumably interacts with host chromosome replication and maintenance factors to facilitate this replication. The adaptive radiation of papillomaviruses in response to changing …


Small Interfering Rna-Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma Apr 2013

Small Interfering Rna-Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma

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

RNA interference (RNAi) is an evolutionarily conserved gene silencing mechanism in eukaryotes, with regulatory roles in a variety of biological processes, including cell cycle, cell differentiation, physiological and metabolic pathways, and stress responses. RNAi can function by transcriptional silencing, mRNA target cleavage, translation repression and/or DNA elimination. In this study, we used the unicellular green alga Chlamydomonas reinhardtii as a model system to study RNAi-mediated translation repression. We demonstrated that small RNAs (sRNAs) generated from exogenously introduced inverted repeat transgenes, with perfect complementarity to the 3’UTR of a target transcript, can inhibit protein synthesis, without or with only minimal mRNA …


Histone Biotinylation In Candida Albicans, Sahar Hasim, Swetha Tati, Nandakumar Madayiputhiya, Renu Nandakumar, Kenneth W. Nickerson Jan 2013

Histone Biotinylation In Candida Albicans, Sahar Hasim, Swetha Tati, Nandakumar Madayiputhiya, Renu Nandakumar, Kenneth W. Nickerson

Kenneth Nickerson Papers

Candida albicans is an opportunistic fungal pathogen in humans. It is a polymorphic fungus: it can live as yeasts, hyphae, or pseudohyphae. Biotin is required for cell growth and fatty acid metabolism because it is used as a cofactor for carboxylases such as acetyl-CoA carboxylase, and pyruvate carboxylase. In addition, we have discovered that biotin is used to modify histones in C. albicans. Biotinylation was detected by Western blots using a monoclonal antibiotin HRP-conjugated antibody as well as with qTOF and LC/MS/MS mass spectrometry. As a precaution, the antibiotin antibody was dialyzed against neutravidin prior to use. During this study, …


Global Neuroaids Roundtable, Jeymohan Joseph, Cristian L. Achim, Michael J. Boivin, Bruce J. Brew, David B. Clifford, Deborah A. Colosi, Ronald J. Ellis, Robert K. Heaton, Amadou Gallo-Diop, Igor Grant, Georgette D. Kanmogne, Mahendra Kumar, Scott Letendre, Thomas D. Marcotte, Avindra Nath, Carlos A. Pardo, Robert H. Paul, Lynn Pulliam, Kevin Robertson, Walter Royal Iii, Ned Sacktor, Pasiri Sithinamsuwan, Davey M. Smith, Victor Valcour, Brian Wigdahl, Charles Wood Jan 2013

Global Neuroaids Roundtable, Jeymohan Joseph, Cristian L. Achim, Michael J. Boivin, Bruce J. Brew, David B. Clifford, Deborah A. Colosi, Ronald J. Ellis, Robert K. Heaton, Amadou Gallo-Diop, Igor Grant, Georgette D. Kanmogne, Mahendra Kumar, Scott Letendre, Thomas D. Marcotte, Avindra Nath, Carlos A. Pardo, Robert H. Paul, Lynn Pulliam, Kevin Robertson, Walter Royal Iii, Ned Sacktor, Pasiri Sithinamsuwan, Davey M. Smith, Victor Valcour, Brian Wigdahl, Charles Wood

Nebraska Center for Virology: Faculty Publications

In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the “Global NeuroAIDS Roundtable” in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the …


Molecular Architecture Of The Uncleaved Hiv-1 Envelope Glycoprotein Trimer, Youdong Mao, Luis Castillo-Menendez, Liping Wang, Christopher Gu, Alon Herschhorn, Anik Désormeaux, Andrés Finzi, Shi-Hua Xiang, Joseph Sodroski Jan 2013

Molecular Architecture Of The Uncleaved Hiv-1 Envelope Glycoprotein Trimer, Youdong Mao, Luis Castillo-Menendez, Liping Wang, Christopher Gu, Alon Herschhorn, Anik Désormeaux, Andrés Finzi, Shi-Hua Xiang, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer, a membrane-fusing machine, mediates virus entry into host cells and is the sole virusspecific target for neutralizing antibodies. Binding the receptors, CD4 and CCR5/CXCR4, triggers Env conformational changes from the metastable unliganded state to the fusion-active state. We used cryo-electron microscopy to obtain a 6-Å structure of the membranebound, heavily glycosylated HIV-1 Env trimer in its uncleaved and unliganded state. The spatial organization of secondary structure elements reveals that the unliganded conformations of both gp120 and gp41 subunits differ from those induced by receptor binding. The gp120 trimer association domains, which …


Candida Albicans Czf1 And Efg1 Coordinate The Response To Farnesol During Quorum Sensing, White-Opaque Thermal Dimorphism, And Cell Death, Melanie L. Langford, Jessica C. Hargarten, Krista D. Patefield, Elizabeth Marta, Jill R. Blankenship, Saranna Fanning, Kenneth W. Nickerson, Audrey L. Atkin Jan 2013

Candida Albicans Czf1 And Efg1 Coordinate The Response To Farnesol During Quorum Sensing, White-Opaque Thermal Dimorphism, And Cell Death, Melanie L. Langford, Jessica C. Hargarten, Krista D. Patefield, Elizabeth Marta, Jill R. Blankenship, Saranna Fanning, Kenneth W. Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

Quorum sensing by farnesol in Candida albicans inhibits filamentation and may be directly related to its ability to cause both mucosal and systemic diseases. The Ras1-cyclic AMP signaling pathway is a target for farnesol inhibition. However, a clear understanding of the downstream effectors of the morphological farnesol response has yet to be unraveled. To address this issue, we screened a library for mutants that fail to respond to farnesol. Six mutants were identified, and the czf1/czf1 mutant was selected for further characterization. Czf1 is a transcription factor that regulates filamentation in embedded agar and also whiteto- opaque switching. We found …


Early Childhood Infection Of Kaposi’S Sarcoma-Associated Herpesvirus In Zambian Households: A Molecular Analysis, Landon Olp, Danielle M. Shea, Maxine K. White, Clement Gondwe, Chipepo Kankasa, Charles Wood Jan 2013

Early Childhood Infection Of Kaposi’S Sarcoma-Associated Herpesvirus In Zambian Households: A Molecular Analysis, Landon Olp, Danielle M. Shea, Maxine K. White, Clement Gondwe, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Sub-Saharan Africa is endemic for Kaposi’s sarcoma-associated herpesvirus (KSHV) and there is a high rate of early childhood infection; however, the transmission sources are not well characterized. We examined household members as potential KSHV transmission sources to young children in the KSHV-endemic country of Zambia. To this end, we enrolled and followed Zambian households with at least one KSHV-seropositive child and collected longitudinal buccal swab samples. KSHV burden was evaluated and K1 sequences from the children were determined and analyzed for differences to K1 sequences from household members. The K1 sequences were also analyzed for evolution over time. We generated …


Towards Defining The Chloroviruses: A Genomic Journey Through A Genus Of Large Dna Viruses, Adrien Jeanniard, David D. Dunigan, James Gurnon, Irina V. Agarkova, Ming Kang, Jason Vitek, Garry Duncan, O William Mcclung, Megan Larsen, Jean-Michel Claverie, James L. Van Etten, Guillaume Blanc Jan 2013

Towards Defining The Chloroviruses: A Genomic Journey Through A Genus Of Large Dna Viruses, Adrien Jeanniard, David D. Dunigan, James Gurnon, Irina V. Agarkova, Ming Kang, Jason Vitek, Garry Duncan, O William Mcclung, Megan Larsen, Jean-Michel Claverie, James L. Van Etten, Guillaume Blanc

Nebraska Center for Virology: Faculty Publications

Background: Giant viruses in the genus Chlorovirus (family Phycodnaviridae) infect eukaryotic green microalgae. The prototype member of the genus, Paramecium bursaria chlorella virus 1, was sequenced more than 15 years ago, and to date there are only 6 fully sequenced chloroviruses in public databases. Presented here are the draft genome sequences of 35 additional chloroviruses (287 – 348 Kb/319 – 381 predicted protein encoding genes) collected across the globe; they infect one of three different green algal species. These new data allowed us to analyze the genomic landscape of 41 chloroviruses, which revealed some remarkable features about these viruses. …


Hiv-1 Env C2-V4 Diversification In A Slow-Progressor Infant Reveals A Flat But Rugged Fitness Landscape, S. Abigail Smith, Charles Wood, John T. West Jan 2013

Hiv-1 Env C2-V4 Diversification In A Slow-Progressor Infant Reveals A Flat But Rugged Fitness Landscape, S. Abigail Smith, Charles Wood, John T. West

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type-1 (HIV-1) fitness has been associated with virus entry, a process mediated by the envelope glycoprotein (Env). We previously described Env genetic diversification in a Zambian, subtype C infected, slow-progressor child (1157i) in parallel with an evolving neutralizing antibody response. Because of the role the Variable-3 loop (V3) plays in transmission, cell tropism, neutralization sensitivity, and fitness, longitudinally isolated 1157i C2-V4 alleles were cloned into HIV-1NL4-3-eGFP and -DsRed2 infectious molecular clones. The fluorescent reporters allowed for dual-infection competitions between all patient-derived C2-V4 chimeras to quantify the effect of V3 diversification and selection on fitness. ‘Winners’ …


Evaluation Of Higher Plant Virus Resistance Genes In The Green Alga, Chlorella Variabilis Nc64a, During The Early Phase Of Infection With Paramecium Bursaria Chlorella Virus-1, Janet M. Rowe, David D. Dunigan, Guillaume Blanc, James R. Gurnon, Yuannan Xia, James L. Van Etten Jan 2013

Evaluation Of Higher Plant Virus Resistance Genes In The Green Alga, Chlorella Variabilis Nc64a, During The Early Phase Of Infection With Paramecium Bursaria Chlorella Virus-1, Janet M. Rowe, David D. Dunigan, Guillaume Blanc, James R. Gurnon, Yuannan Xia, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

With growing industrial interest in algae plus their critical roles in aquatic systems, the need to understand the effects of algal pathogens is increasing. We examined a model algal host–virus system, Chlorella variabilis NC64A and virus, PBCV-1. C. variabilis encodes 375 homologs to genes involved in RNA silencing and in response to virus infection in higher plants. Illumina RNA-Seq data showed that 325 of these homologs were expressed in healthy and early PBCV-1 infected (≤60 min) cells. For each of the RNA silencing genes to which homologs were found, mRNA transcripts were detected in healthy and infected cells. C. variabilis …


A Twin-Cysteine Motif In The V2 Region Of Gp120 Is Associated With Siv Envelope Trimer Stabilization, Christopher Bohl, Dane Bowder, Jesse Thompson, Levon Abrahamyan, Sandra Gonzalez-Ramirez, Youdong Mao, Joseph Sodroski, Charles Wood, Shi-Hua Xiang Jan 2013

A Twin-Cysteine Motif In The V2 Region Of Gp120 Is Associated With Siv Envelope Trimer Stabilization, Christopher Bohl, Dane Bowder, Jesse Thompson, Levon Abrahamyan, Sandra Gonzalez-Ramirez, Youdong Mao, Joseph Sodroski, Charles Wood, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

The V1 and V2 variable regions of the primate immunodeficiency viruses contribute to the trimer association domain of the gp120 exterior envelope glycoprotein. A pair of V2 cysteine residues at 183 and 191 (‘‘twin cysteines’’) is present in several simian immunodeficiency viruses, human immunodeficiency virus type 2 (HIV-2) and some SIVcpz lineages, but not in HIV-1. To examine the role of this potentially disulfide-bonded twin-cysteine motif, the cysteine residues in the SIVmac239 envelope glycoproteins were individually and pairwise substituted by alanine residues. All of the twin-cysteine mutants exhibited decreases in gp120 association with the Env trimer, membrane-fusing activity, and …


Variations In The Biological Functions Of Hiv-1 Clade C Envelope In A Shiv-Infected Rhesus Macaque During Disease Progression, For Yue Tso, Levon Abrahamyan, Shiu-Lok Hu, Ruth M. Ruprecht, Charles Wood Jan 2013

Variations In The Biological Functions Of Hiv-1 Clade C Envelope In A Shiv-Infected Rhesus Macaque During Disease Progression, For Yue Tso, Levon Abrahamyan, Shiu-Lok Hu, Ruth M. Ruprecht, Charles Wood

Nebraska Center for Virology: Faculty Publications

A better understanding of how the biological functions of the HIV-1 envelope (Env) changes during disease progression may aid the design of an efficacious anti-HIV-1 vaccine. Although studies from patient had provided some insights on this issue, the differences in the study cohorts and methodology had make it difficult to reach a consensus of the variations in the HIV-1 Env functions during disease progression. To this end, an animal model that can be infected under controlled environment and reflect the disease course of HIV-1 infection in human will be beneficial. Such an animal model was previously demonstrated by the infection …


‘‘Megavirales’’, A Proposed New Order For Eukaryotic Nucleocytoplasmic Large Dna Viruses, Philippe Colson, Xavier De Lamballerie, Natalya Yutin, Sassan Asgari, Yves Bigot, Dennis K. Bideshi, Xiao-Wen Cheng, Brian A. Federici, James L. Van Etten, Eugene V. Koonin, Bernard La Scola, Didier Raoult Jan 2013

‘‘Megavirales’’, A Proposed New Order For Eukaryotic Nucleocytoplasmic Large Dna Viruses, Philippe Colson, Xavier De Lamballerie, Natalya Yutin, Sassan Asgari, Yves Bigot, Dennis K. Bideshi, Xiao-Wen Cheng, Brian A. Federici, James L. Van Etten, Eugene V. Koonin, Bernard La Scola, Didier Raoult

Nebraska Center for Virology: Faculty Publications

The nucleocytoplasmic large DNA viruses (NCLDVs) comprise a monophyletic group of viruses that infect animals and diverse unicellular eukaryotes. The NCLDV group includes the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Mimiviridae and the proposed family ‘‘Marseilleviridae’’. The family Mimiviridae includes the largest known viruses, with genomes in excess of one megabase, whereas the genome size in the other NCLDV families varies from 100 to 400 kilobase pairs. Most of the NCLDVs replicate in the cytoplasm of infected cells, within so-called virus factories. The NCLDVs share a common ancient origin, as demonstrated by evolutionary reconstructions that trace approximately 50 genes encoding …


Recent Advances On The Use Of Structural Biology For The Design Of Novel Envelope Immunogens Of Hiv-1, Shi-Hua Xiang Jan 2013

Recent Advances On The Use Of Structural Biology For The Design Of Novel Envelope Immunogens Of Hiv-1, Shi-Hua Xiang

Nebraska Center for Virology: Faculty Publications

Many efforts have been made in the worldwide quest for a prophylactic HIV vaccine to end the AIDS pandemic, but none has yet succeeded. The lessons learned have repeatedly informed us that the traditional or conventional approaches directly using the pathogens or subunits will not be sufficient for an effective HIV/AIDS vaccine. Recent advances in structure-based technology have shown some promise in the quest for a better immunogen in HIV vaccine development. According to the basic binding structural relationship of an antigen and an antibody, structure-based antigen design could bring some hope for the development of an effective vaccine against …


The Highly Conserved Layer-3 Component Of The Hiv-1 Gp120 Inner Domain Is Critical For Cd4-Required Conformational Transitions, Anik Désormeaux, Mathieu Coutu, Halima Medjahed, Beatriz Pacheco, Alon Herschhorn, Christopher Gu, Shi-Hua Xiang, Youdong Mao, Joseph Sodroski, Andrés Finzi Jan 2013

The Highly Conserved Layer-3 Component Of The Hiv-1 Gp120 Inner Domain Is Critical For Cd4-Required Conformational Transitions, Anik Désormeaux, Mathieu Coutu, Halima Medjahed, Beatriz Pacheco, Alon Herschhorn, Christopher Gu, Shi-Hua Xiang, Youdong Mao, Joseph Sodroski, Andrés Finzi

Nebraska Center for Virology: Faculty Publications

The trimeric envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) mediates virus entry into host cells. CD4 engagement with the gp120 exterior envelope glycoprotein subunit represents the first step during HIV-1 entry. CD4-induced conformational changes in the gp120 inner domain involve three potentially flexible topological layers (layers 1, 2, and 3). Structural rearrangements between layer 1 and layer 2 have been shown to facilitate the transition of the envelope glycoprotein trimer from the unliganded to the CD4-bound state and to stabilize gp120-CD4 interaction. However, our understanding of CD4-induced conformational changes in the gp120 inner domain remains incomplete. Here, …


Low-Abundance Resistant Mutations In Hiv-1 Subtype C Antiretroviral Therapy-Naïve Individuals As Revealed By Pyrosequencing, Sandra Gonzalez, Damien C. Tully, Clement Gondwe, Charles Wood Jan 2013

Low-Abundance Resistant Mutations In Hiv-1 Subtype C Antiretroviral Therapy-Naïve Individuals As Revealed By Pyrosequencing, Sandra Gonzalez, Damien C. Tully, Clement Gondwe, Charles Wood

Nebraska Center for Virology: Faculty Publications

Given the recent scale-up of antiretroviral therapy (ART) in sub-Saharan Africa, we sought to determine how often and at what levels do drug-resistant mutant variants exist in ART-naïve HIV subtype C infected individuals. Samples from 10 ART-naïve Zambian individuals were subjected to ultra-deep pyrosequencing (UDPS) to characterize the frequency of low-abundance drug resistance mutations in the pol gene. Low-abundance clinically relevant variants were detected for nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) in eight of the ten subjects. Intermediate to high-level resistance was predicted for the majority of NRTIs. Mutations conferring resistance to …


Analysis Of Primary Resistance Mutations To Hiv-1 Entry Inhibitors In Therapy Naive Subtype C Hiv-1 Infected Mother– Infant Pairs From Zambia, Hongyan Guo, Chang Liu, Bin Liu, Charles Wood, Xiaohong Kong Jan 2013

Analysis Of Primary Resistance Mutations To Hiv-1 Entry Inhibitors In Therapy Naive Subtype C Hiv-1 Infected Mother– Infant Pairs From Zambia, Hongyan Guo, Chang Liu, Bin Liu, Charles Wood, Xiaohong Kong

Nebraska Center for Virology: Faculty Publications

Background—Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT.

Objectives—To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc.

Study design—Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were …


Kaposi’S Sarcoma-Associated Herpesvirus Transactivator Rta Induces Cell Cycle Arrest In G0/G1 Phase By Stabilizing And Promoting Nuclear Localization Of P27Kip, Pankaj Kumar, Charles Wood Jan 2013

Kaposi’S Sarcoma-Associated Herpesvirus Transactivator Rta Induces Cell Cycle Arrest In G0/G1 Phase By Stabilizing And Promoting Nuclear Localization Of P27Kip, Pankaj Kumar, Charles Wood

Nebraska Center for Virology: Faculty Publications

The Kaposi’s sarcoma-associated herpesvirus (KSHV) immediate-early gene, replication, and transcription activator (KRta) is a key viral protein that serves as the master regulator for viral lytic replication. In this study, we investigated the role of K-Rta in cell cycle regulation and found that the expression of K-Rta in doxycycline (Dox)-inducible BJAB cells induced cell cycle arrest in G0/G1 phase. Western blot analysis of key cell cycle regulators revealed that K-Rta-mediated cell cycle arrest was associated with a decrease in cyclin A and phosphorylated Rb (pS807/pS811) protein levels, both markers of S phase progression, and an increase in …


Clade C Hiv-1 Isolates Circulating In Southern Africa Exhibit A Greater Frequency Of Dicysteine Motif-Containing Tat Variants Than Those In Southeast Asia And Cause Increased Neurovirulence, Vasudev R. Rao, Ujjwal Neogi, Joshua S, Talboom, Ligia Padilla, Mustafizur Rahman, Cari Fritz-French, Sandra Gonzalez-Ramirez, Anjali Verma, Charles Wood, Ruth M. Ruprecht, Udaykumar Ranga, Tasnim Azim, Vinayaka R. Prasad Jan 2013

Clade C Hiv-1 Isolates Circulating In Southern Africa Exhibit A Greater Frequency Of Dicysteine Motif-Containing Tat Variants Than Those In Southeast Asia And Cause Increased Neurovirulence, Vasudev R. Rao, Ujjwal Neogi, Joshua S, Talboom, Ligia Padilla, Mustafizur Rahman, Cari Fritz-French, Sandra Gonzalez-Ramirez, Anjali Verma, Charles Wood, Ruth M. Ruprecht, Udaykumar Ranga, Tasnim Azim, Vinayaka R. Prasad

Nebraska Center for Virology: Faculty Publications

Background: HIV-1 Clade C (Subtype C; HIV-1C) is responsible for greater than 50% of infections worldwide. Unlike clade B HIV-1 (Subtype B; HIV-1B), which is known to cause HIV associated dementia (HAD) in approximately 15% to 30% of the infected individuals, HIV-1C has been linked with lower prevalence of HAD (0 to 6%) in India and Ethiopia. However, recent studies report a higher prevalence of HAD in South Africa, Zambia and Botswana, where HIV-1C infections predominate. Therefore, we examined whether Southern African HIV-1C is genetically distinct and investigated its neurovirulence. HIV-1 Tat protein is a viral determinant of neurocognitive dysfunction. …


Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia, Eliso Mamisashvili, Ian T. Kracalik, Tinatin Onashvili, Lela Kerdzevadze, Ketevan Goginashvili, Tamar Tigilauri, Marina Donduashvili, Marina Nikolaishvili, Irma Beradze, Marina Zakareishvili, Maka Kokhreidze, Makvala Gelashvili, Nino Vepkhvadze, S. Elizabeth Rácz, Philip H. Elzer, Mikeljon P. Nikolich, Jason K. Blackburn Jan 2013

Seroprevalence Of Brucellosis In Livestock Within Three Endemic Regions Of The Country Of Georgia, Eliso Mamisashvili, Ian T. Kracalik, Tinatin Onashvili, Lela Kerdzevadze, Ketevan Goginashvili, Tamar Tigilauri, Marina Donduashvili, Marina Nikolaishvili, Irma Beradze, Marina Zakareishvili, Maka Kokhreidze, Makvala Gelashvili, Nino Vepkhvadze, S. Elizabeth Rácz, Philip H. Elzer, Mikeljon P. Nikolich, Jason K. Blackburn

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Brucellosis is the one of most common livestock zoonoses in Georgia, resulting in significant economic losses. Livestock were sampled in three regions of Georgia (Kakheti, Kvemo Kartli, Imereti). Districts that historically reported high numbers of brucellosis related morbidity were selected for serological, bacteriological and molecular surveys. Surveying efforts yielded samples from 10,819 large and small ruminants. In total, 735 serological tests were positive on Rose Bengal and 33 bacterial isolates were recovered and identified as Brucella melitensis or Brucella abortus by microbiology and AMOS-PCR. A Bayesian framework was implemented to estimate the true prevalence of the disease given an imperfect …