Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Microbiology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1711 - 1740 of 2230

Full-Text Articles in Entire DC Network

Changes To The Equine Hindgut Microflora In Response To Antibiotic Challenge, Brittany E. Harlow Jan 2012

Changes To The Equine Hindgut Microflora In Response To Antibiotic Challenge, Brittany E. Harlow

Theses and Dissertations--Animal and Food Sciences

Antibiotics are important to equine medicine, but can cause detrimental side-effects including reduced feed intake, allergic reactions, and diarrhea. Antibiotic-associated diarrhea (AAD) is attributed to disruption of the hindgut microflora, permitting proliferation of pathogenic microbes. The objectives were to evaluate the effects of antibiotics on beneficial fecal bacteria, AAD-associated pathogens, microbial species richness and fermentation. Horses were assigned to treatment groups: control (no antibiotics, n=6), trimethoprim-sulfadiazine (oral, n=6), or sodium ceftiofur (IM, n=6). Fecal samples were taken during adaptation (3 wk), antibiotic challenge (1 wk), and withdrawal (1 wk). Fecal cellulolytics decreased by >99% during challenge and did not recover …


Siv Infection Induces Accumulation Of Plasmacytoid Dendritic Cells In The Gut Mucosa, R. Keith Reeves, Tristan I. Evans, Jacqueline Gillis, Fay E. Wong, Guobin Kang, Qingsheng Li, R. Paul Johnson Jan 2012

Siv Infection Induces Accumulation Of Plasmacytoid Dendritic Cells In The Gut Mucosa, R. Keith Reeves, Tristan I. Evans, Jacqueline Gillis, Fay E. Wong, Guobin Kang, Qingsheng Li, R. Paul Johnson

Nebraska Center for Virology: Faculty Publications

Multiple studies suggest that plasmacytoid dendritic cells (pDCs) are depleted and dysfunctional during human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) infection, but little is known about pDCs in the gut—the primary site of virus replication. Here, we show that during SIV infection, pDCs were reduced 3-fold in the circulation and significantly upregulated the gut-homing marker α4β7, but were increased 4-fold in rectal biopsies of infected compared to naive macaques. These data revise the understanding of pDC immunobiology during SIV infection, indicating that pDCs are not necessarily depleted, but instead may traffic to and accumulate in the gut mucosa.


Triticum Mosaic Poacevirus Enlists P1 Rather Than Hc-Pro To Suppress Rna Silencing-Mediated Host Defense, Satyanarayana Tatineni, Feng Qu, Ruhui Li, Thomas Jack Morris, Roy French Jan 2012

Triticum Mosaic Poacevirus Enlists P1 Rather Than Hc-Pro To Suppress Rna Silencing-Mediated Host Defense, Satyanarayana Tatineni, Feng Qu, Ruhui Li, Thomas Jack Morris, Roy French

Nebraska Center for Virology: Faculty Publications

Triticum mosaic virus (TriMV) is the type species of the newly established Poacevirus genus in the family Potyviridae. In this study, we demonstrate that in contrast to the helper component- proteinase (HC-Pro) of Potyvirus species, the P1 proteins of TriMV and Sugarcane steak mosaic poacevirus function in suppression of RNA silencing (SRS). TriMV P1 effectively suppressed silencing induced by single- or double-stranded RNAs (ss/ds RNAs), and disrupted the systemic spread of silencing signals at a step after silencing signal production. Interestingly, contrary to enhanced SRS activity of potyviral HC-Pro by co-expression with P1, the presence of TriMV HC-Pro reduced …


Identification Of Molecular Determinants From Moloney Leukemia Virus 10 Homolog (Mov10) Protein For Virion Packaging And Anti-Hiv-1 Activity, Aierken Abudu, Xiaojun Wang, Ying Dang, Tao Zhou, Shi-Hua Xiang, Yong -Hui Zheng Jan 2012

Identification Of Molecular Determinants From Moloney Leukemia Virus 10 Homolog (Mov10) Protein For Virion Packaging And Anti-Hiv-1 Activity, Aierken Abudu, Xiaojun Wang, Ying Dang, Tao Zhou, Shi-Hua Xiang, Yong -Hui Zheng

Nebraska Center for Virology: Faculty Publications

Background: MOV10 inhibits HIV-1 replication after being packaged.

Results: A Gag binding plus all but one of seven helicase domains are required for MOV10 packaging. Nearly all residues are required for anti-HIV-1 activity. Conclusion: Gag binding is not sufficient for MOV10 packaging, and multiple discontinuous domains regulate MOV10 activity.

Significance: These findings uncover a new packaging mechanism and provide new insights into MOV10 antiviral activity.


An Ims/Atp Assay For The Detection Of Mycobacterium Tuberculosis In Urine, Dawn M. Hunter, Daniel V. Lim Jan 2012

An Ims/Atp Assay For The Detection Of Mycobacterium Tuberculosis In Urine, Dawn M. Hunter, Daniel V. Lim

Molecular Biosciences Faculty Publications

Background. Although sputum smears are the gold standard for diagnosis of tuberculosis, sensitivity in HIV/TB coinfection cases is low, indicating a need for alternative methods. Urine is being increasingly evaluated. Materials and Methods. A novel method for detecting Mycobacterium tuberculosis (MTB) in synthetic urine using a combined IMS/ATP assay was evaluated. Preliminary work established standard ATP conditions and the sensitivity and specificity of the MTB antibody. Eighty-four blinded samples in four replicate assays were evaluated for the presence of MTB using labeled immunomagnetic beads for capture. Beads were separated, washed, and resuspended in broth and added to a …


Antimicrobial Activity, Cytotoxicity And Phytochemical Analyses Of Rhus Aromatica, Rhus Glabra And Sanguinaria Canadensis Native To South Dakota, Gitanjali Nandakafle Jan 2012

Antimicrobial Activity, Cytotoxicity And Phytochemical Analyses Of Rhus Aromatica, Rhus Glabra And Sanguinaria Canadensis Native To South Dakota, Gitanjali Nandakafle

Electronic Theses and Dissertations

A total of twenty five South Dakota native medicinal plants were screened against enterotoxigenic Escherichia coli using a disk diffusion assay. Out of these 25 plants, three plants Rhus aromatica, Rhus glabra and Sanguinaria canadensis demonstrated the highest bacterial inhibition. The minimum inhibitory concentrations (MIC) of these plant extracts were determined using a bacterial enumeration assay. Alamar Blue in vitro cytotoxicity test showed that all extracts have some toxic effect to porcine intestinal epithelial cell lines. Phytochemical analysis of these plant extracts indicated the presence high concentration of flavonoids and condensed tannins in R. aromatica and that R. glabra contained …


Intra And Interhost Dynamics Shaping Arbovirus Adaptation And Evolution, Alexander T. Ciota Jan 2012

Intra And Interhost Dynamics Shaping Arbovirus Adaptation And Evolution, Alexander T. Ciota

Legacy Theses & Dissertations (2009 - 2024)

Arthropod-borne viruses (arboviruses), which are predominately mosquito-borne and almost exclusively RNA viruses, are maintained in nature in complex transmission cycles involving blood sucking invertebrates and vertebrate hosts. Although over 120 arboviruses are human pathogens responsible for causing a significant and expanding global health burden, a detailed understanding of the complex interactions between these pathogens and their hosts, particularly invertebrate hosts, is lacking. Defining these interactions is necessary if we are to understand the selective pressures and, therefore, evolutionary, adaptive, and epidemiological potential of arboviruses. This requires experimental infection and evolution studies, particularly in vivo, with natural hosts. The results presented …


Dynamics Of Envelope Evolution In Clade C Shiv-Infected Pig-Tailed Macaques During Disease Progression Analyzed By Ultra-Deep Pyrosequencing, For Yue Tso, Damien C. Tully, Sandra Gonzalez, Christopher Quince, On Ho, Patricia Polacino, Ruth M. Ruprecht, Shiu-Lok Hu, Charles Wood Jan 2012

Dynamics Of Envelope Evolution In Clade C Shiv-Infected Pig-Tailed Macaques During Disease Progression Analyzed By Ultra-Deep Pyrosequencing, For Yue Tso, Damien C. Tully, Sandra Gonzalez, Christopher Quince, On Ho, Patricia Polacino, Ruth M. Ruprecht, Shiu-Lok Hu, Charles Wood

Nebraska Center for Virology: Faculty Publications

Understanding the evolution of the human immunodeficiency virus type 1 (HIV-1) envelope during disease progression can provide tremendous insights for vaccine development, and simian-human immunodeficiency virus (SHIV) infection of nonhuman primate provides an ideal platform for such studies. A newly developed clade C SHIV, SHIV-1157ipd3N4, which was able to infect rhesus macaques, closely resembled primary HIV-1 in transmission and pathogenesis, was used to infect several pig-tailed macaques. One of the infected animals subsequently progressed to AIDS, whereas one remained a nonprogressor. The viral envelope evolution in the infected animals during disease progression was analyzed by a bioinformatics approach using ultra-deep …


Coxsackievirus B3 Infection Leads To The Generation Of Cardiac Myosin Heavy Chain-Α-Reactive Cd4 T Cells In A/J Mice, Arunakumar Gangaplara, Chandirasegaran Massilamany, Deborah M. Brown, Gustavo A. Delhon, Asit K. Pattnaik, Nora Chapman, Noel Rose, David J. Steffen, Jay Reddy Jan 2012

Coxsackievirus B3 Infection Leads To The Generation Of Cardiac Myosin Heavy Chain-Α-Reactive Cd4 T Cells In A/J Mice, Arunakumar Gangaplara, Chandirasegaran Massilamany, Deborah M. Brown, Gustavo A. Delhon, Asit K. Pattnaik, Nora Chapman, Noel Rose, David J. Steffen, Jay Reddy

Jay Reddy Publications

Enteroviruses like coxsackievirus B3 (CVB3) are common suspects in myocarditis/dilated cardiomyopathy patients. Autoimmunity has been proposed as an underlying mechanism, but direct evidence of its role is lacking. To delineate autoimmune response in CVB3 myocarditis, we used IAk dextramers for cardiac myosin heavy chain (Myhc)-α 334–352. We have demonstrated that myocarditis-susceptible A/J mice infected with CVB3 generate Myhc-α-reactive CD4 T cells and such a repertoire was absent in naïve mice as measured by proliferative response to Myhc-α 334–352 and IAk dextramer staining. We also detected Myhc-α 334–352 dextramer+ cells in the hearts of CVB3-infected mice. The autoreactive …


Examining Autoimmune Sequelae During Cancer Immunotherapy In A Combined Autoimmune Thyroiditis And Tumor Mouse Model, Suresh Kari Jan 2012

Examining Autoimmune Sequelae During Cancer Immunotherapy In A Combined Autoimmune Thyroiditis And Tumor Mouse Model, Suresh Kari

Wayne State University Dissertations

Some clinical trials of immunotherapeutic agents against cancers have resulted in the development of autoimmune sequelae, including autoimmune thyroiditis. It has been suggested that the immunotherapy resulted in an alteration in the immunoregulatory mechanism(s). Using experimental autoimmune thyroiditis (EAT), a mouse model of Hashimoto's thyroiditis (HT), the importance of regulatory T cells (Tregs) has been well established; inhibition of Tregs leads to enhanced thyroiditis with repeated doses of mouse thyroglobulin (mTg) without adjuvant. To simulate cancer patients, we developed a combined EAT and tumor model in our EAT-susceptible mice (CBA/J). In first establishing the tumor model, we found Treg depletion …


Membrane-Bound Immunomodulators As Adjuvants In A Cell Culture-Based Avian Influenza Vaccine, David Daniel Fischer Jan 2012

Membrane-Bound Immunomodulators As Adjuvants In A Cell Culture-Based Avian Influenza Vaccine, David Daniel Fischer

Wayne State University Dissertations

Inactivated viral vaccines often generate suboptimal immune responses. Adjuvants are incorporated into vaccines to increase their immunogenicity, however currently available adjuvants have shortcomings which have limited their use in human and veterinary medicine. This necessitates the development of new adjuvants and delivery systems. Cytokines have been extensively tested as adjuvants in vaccines but challenges such as diffusion from antigen, short half-lives and production costs have been encountered. To address this, we developed a technology that efficiently produces inactivated, whole-virus influenza vaccine bearing membrane-bound cytokines. Tethering the cytokine to the antigen of interest keeps the immunomodulator in close contact with the …


In Silico Prediction Of Protein-Protein Interactions Between Cronobacter Sakazakii And Human Host, Sean Held Jan 2012

In Silico Prediction Of Protein-Protein Interactions Between Cronobacter Sakazakii And Human Host, Sean Held

Theses

The genus Cronobacter accommodates 16 biogroups of the emerging opportunistic pathogen known formerly as Enterobacter sakazakii. Cronobacter are occasional contaminants of milk powder and, consequently, powdered infant formula (PIT). Since it is a pathogen that is transmitted in infant formula it represents a significant health risk to neonates. These bacteria are opportunistic pathogens (can only cause disease when the host's resistance is low) and are linked with life-threatening infections in neonates. Some of the clinical symptoms of Cronohacter infection include necrotizing enterocolitis, bacteremia, and meningitis, with case fatality rates of 50-80% being reported (Healy et al. 2010). Infant formula manufacturers …


Examination Of The Prevalence And Persistence Of Pathogenic Staphylococci On Euro Currency, Emma Gabriel Jan 2012

Examination Of The Prevalence And Persistence Of Pathogenic Staphylococci On Euro Currency, Emma Gabriel

Theses

Staphylococci are a diverse group of bacteria that cause diseases ranging from minor skin infections to life-threatening bacteremia. Methicillin-resistant S. aureus (MRSA) is the most common multidrug-resistant nosocomial pathogen in Europe estimated to cause 170,000 infections resulting in more than 5,000 deaths and additional healthcare costs of approximately €380 million annually (Kock et al., 201 1). Whilst rarely life-threatening, coagulase-negative staphylococci (CoNS), in particular S. epidermidis are responsible for the majority of indwelling medical device failures, causing intrinsically resistant biofilm infections, estimated to cost $2 billion per year in additional healthcare costs in the U.S. alone (Otto, 2009).

It is …


Purification And Applications Of A Bacteriophage-Derived Enzyme Chapk Against Problematic Staphylococci., Niamh Marie O'Shea Jan 2012

Purification And Applications Of A Bacteriophage-Derived Enzyme Chapk Against Problematic Staphylococci., Niamh Marie O'Shea

Theses

The bacteriophage K-derived peptidase CHAPk (Cysteine/Histidine-dependant amidohydrolase peptidase) can be produced from E. coli XL 1-Blue. Standard operating procedures for the production, purification and quality assessment of the peptidase were developed and set out in detail in this thesis. CHAPk exhibits strong antistaphylococcal properties and the purified enzyme was evaluated for its potential to eliminate S. aureus from the bovine udder and from human skin. As a teat dip CHAPk reduced the levels of S. aureus by three to five log cycles on both animal and human surfaces. CHAPk activity in milk was evaluated using challenge assays against the bovine …


Establishment Of A Quiescent Infection Of Hsv-1 In L929 Fibroblasts Using A Mitotic Inhibitor And Ifn-Γ, Neelam V. Shinde Jan 2012

Establishment Of A Quiescent Infection Of Hsv-1 In L929 Fibroblasts Using A Mitotic Inhibitor And Ifn-Γ, Neelam V. Shinde

Browse all Theses and Dissertations

The goal for this study was to determine if a quiescent infection of HSV-1 could be induced in murine fibroblasts L929 by treating them with the anti-mitotic agent 5-fluoro 2'deoxy uridine (FUDR) alone and with interferon-γ. Since neurons are post-mitotic and exhibit a lower metabolic rate than other cells, fibroblasts were treated with FUDR to induce a post-mitotic state. The cell cycle arrest of fibroblasts would decrease the thymidylate metabolism and impair HSV-1 replication. An evaluation of cytopathic effects of FUDR was used to determine the optimal concentration which arrests cell growth and inhibits viral replication. Image J program developed …


Q-Ve-Oph, A Control Caspase Inhibitor For Analyzing Neuronal Death, Rebecca L. Bricker Jan 2012

Q-Ve-Oph, A Control Caspase Inhibitor For Analyzing Neuronal Death, Rebecca L. Bricker

Browse all Theses and Dissertations

Sarin is a neurotoxin that has been used in terrorist attacks in Japan and is a potential bioterrorist weapon. It induces seizures by affecting the regulation of neurotransmitters in the brain. Seizures are directly correlated to neuronal damage. Two types of neuronal damage that can occur are apoptosis and necrosis. One of the main regions of the brain where neuronal death occurs is the hippocampus, which is involved in memory. Victims showed chronic decline of memory loss 3 and 7 years after the Tokyo's terrorist attack incident. There are treatments available that can break down sarin or can block the …


The Effects Of Enteropathogenic And Commensal Escherichia Coli On Tight Junction Permeability, Hilary Kaye Allen Jan 2012

The Effects Of Enteropathogenic And Commensal Escherichia Coli On Tight Junction Permeability, Hilary Kaye Allen

Browse all Theses and Dissertations

The intestinal mucosa maintains a barrier between materials from the external environment and the internal environment of the host. Disruption of the gut wall integrity is involved in the development of various intestinal diseases, such as Irritable Bowel Syndrome (IBS) and Crohn's disease. The intestinal mucosa is lined with epithelial cells that are connected by tight junctions, the intercellular junctions that form a selectively permeable barrier between paracellular pathways. Enteric pathogens, such as enteropathogenic Escherichia coli (EPEC), can disrupt the tight junctions of epithelial cells by altering the cellular cytoskeleton or by directly affecting tight junction proteins. Commensal Escherichia coli …


Mhc Class I Expression In Murine Fibroblast And Keratinocyte Cell Lines During The First Twenty-Four Hours Of Infection With Herpes Simplex Virus-1 (Hsv-1), Prasanthi Kumchala Jan 2012

Mhc Class I Expression In Murine Fibroblast And Keratinocyte Cell Lines During The First Twenty-Four Hours Of Infection With Herpes Simplex Virus-1 (Hsv-1), Prasanthi Kumchala

Browse all Theses and Dissertations

The hypothesis of this study is: HSV-1 infection of murine fibroblasts and keratinocytes inhibits expression of MHC class I molecules during first 24 hours of infection. IFN-γ pretreatment of fibroblasts protected the cells from virus-induced inhibition of MHC class I expression, but did not protect keratinocytes. Herpesviruses are known for their ability to establish persistent infections. Herpesviruses exert many different ways to suppress host defense mechanisms. One such way is by down regulating expression of the major histocompatibility complex I (MHC I) molecules in infected cells. Epidermal cells such as keratinocytes are the major sites for herpes simplex virus type …


The Effects Of Hsv-1 Challenge On Polarized Murine Macrophages: An In Vitro Model Using The J774a.1 Murine Macrophage Cell Line, Adam Craig Reichard Jan 2012

The Effects Of Hsv-1 Challenge On Polarized Murine Macrophages: An In Vitro Model Using The J774a.1 Murine Macrophage Cell Line, Adam Craig Reichard

Browse all Theses and Dissertations

In our current study we examined the effects of HSV-1 challenge on J774A.1 macrophages polarized to either a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Polarized J774A.1 macrophages were characterized using CD14-CD86 and SOCS1-SOCS3 expression levels. SOCS proteins are a family of proteins that are capable of inhibiting cytokine-signaling pathways. HSV-1 up regulates expression of SOCS1 protein levels in infected cells, inhibiting the ability of infected cells to produce proinflammatory products (Nowoslawski Akhtar and Benveniste, 2011). This study shows that signals within the microenvironment play a greater role in macrophage polarization, and SOCS1-SOCS3 expression levels, than does HSV-1 challenge. M1 macrophages …


Suppressor Of Cytokine Signaling (Socs) 1 & 3 Expression In Hsv-1- Infected And Interferon-Γ-Treated Neuro-2a Cells, Melinda Jones Jan 2012

Suppressor Of Cytokine Signaling (Socs) 1 & 3 Expression In Hsv-1- Infected And Interferon-Γ-Treated Neuro-2a Cells, Melinda Jones

Browse all Theses and Dissertations

This study examined the effects of HSV-1 infection and IFN-γ treatment on Neuro-2A cells. HSV-1 induces expression of SOCS1 and SOCS3 in infected cells, inhibiting the ability of these cells to produce the pro inflammatory, antiviral cytokine IFN-γ (Nowoslawski and Benveniste, 2011). SOCS1 and SOCS3 levels were determined in IFN-γ-treated cells, virus-infected cells, and cells that were both IFN-γ-treated and virus-infected. Results were compared with untreated, uninfected control cells. Flow cytometry data analysis showed a slight decrease in SOCS1 and SOCS3 protein levels in cells treated with IFN-γ for 6 hours compared to control cells. A significant decrease in SOCS1 …


The Construction Of A Plasmid For Detecting The Pathway Of Arginine Metabolism In Human Macrophages: A Real-Time Assessment Of Macrophage Polarity, Benjamin A. Holmes Jan 2012

The Construction Of A Plasmid For Detecting The Pathway Of Arginine Metabolism In Human Macrophages: A Real-Time Assessment Of Macrophage Polarity, Benjamin A. Holmes

Browse all Theses and Dissertations

Macrophages are "first responders", innate immune system cells which quickly arrive to a site of infection and injury, consuming cell debris and foreign matter and recruiting other immune system cells to the area. While historically they have been thought to react uniformly to all challenges, the discovery of toll-like receptors has shown that macrophages actually work closely with the adaptive immune system in fine-tuning the immune response. Furthermore, it has recently been discovered that macrophages can become polarized to one of two subtypes-M1 or M2.

M1 macrophages are efficient producers of reactive oxygen species, nitrogen intermediates, and inflammatory cytokines. They …


Efficient And Robust Rna-Seq Process For Cultured Bacteria And Complex Community Transcriptomes, Georgia Giannoukos, Dawn M. Ciulla, Katherine Huang, Brian J. Haas, Jacques Izard, Joshua Z. Levin, Jonathan Livny, Ashlee M. Earl, Dirk Gevers, Doyle V. Ward, Chad Nusbaum, Bruce W. Birren, Andreas Gnirke Jan 2012

Efficient And Robust Rna-Seq Process For Cultured Bacteria And Complex Community Transcriptomes, Georgia Giannoukos, Dawn M. Ciulla, Katherine Huang, Brian J. Haas, Jacques Izard, Joshua Z. Levin, Jonathan Livny, Ashlee M. Earl, Dirk Gevers, Doyle V. Ward, Chad Nusbaum, Bruce W. Birren, Andreas Gnirke

Department of Food Science and Technology: Faculty Publications

We have developed a process for transcriptome analysis of bacterial communities that accommodates both intact and fragmented starting RNA and combines efficient rRNA removal with strand-specific RNA-seq. We applied this approach to an RNA mixture derived from three diverse cultured bacterial species and to RNA isolated from clinical stool samples. The resulting expression profiles were highly reproducible, enriched up to 40-fold for non-rRNA transcripts, and correlated well with profiles representing undepleted total RNA.


Chloroviruses: Not Your Everyday Plant Virus, James L. Van Etten, David D. Dunigan Jan 2012

Chloroviruses: Not Your Everyday Plant Virus, James L. Van Etten, David D. Dunigan

Nebraska Center for Virology: Faculty Publications

Viruses infecting higher plants are among the smallest viruses known and typically have four to ten protein-encoding genes. By contrast, many viruses that infect algae (classified in the virus family Phycodnaviridae) are among the largest viruses found to date and have up to 600 protein- encoding genes. This brief review focuses on one group of plaque-forming phycodnaviruses that infect unicellular chlorella-like green algae. The prototype chlorovirus PBCV-1 has more than 400 protein-encoding genes and 11 tRNA genes. About 40% of the PBCV-1 encoded proteins resemble proteins of known function including many that are completely unexpected for a virus. In many …


Molecular Genetic And Biochemical Characterization Of The Vaccinia Virus I3 Protein, The Replicative Single-Stranded Dna Binding Protein, Matthew D. Greseth, Kathleen A. Boyle, Matthew S. Bluma, Bethany Unger, Matthew S. Wiebe, Jamaria A. Soares-Martins, Nadi T. Wickramasekera, James Wahlberg, Paula Traktman Jan 2012

Molecular Genetic And Biochemical Characterization Of The Vaccinia Virus I3 Protein, The Replicative Single-Stranded Dna Binding Protein, Matthew D. Greseth, Kathleen A. Boyle, Matthew S. Bluma, Bethany Unger, Matthew S. Wiebe, Jamaria A. Soares-Martins, Nadi T. Wickramasekera, James Wahlberg, Paula Traktman

Nebraska Center for Virology: Faculty Publications

Vaccinia virus, the prototypic poxvirus, efficiently and faithfully replicates its approximately 200-kb DNA genome within the cytoplasm of infected cells. This intracellular localization dictates that vaccinia virus encodes most, if not all, of its own DNA replication machinery. Included in the repertoire of viral replication proteins is the I3 protein, which binds to single-stranded DNA (ssDNA) with great specificity and stability and has been presumed to be the replicative ssDNA binding protein (SSB). We substantiate here that I3 colocalizes with bromodeoxyuridine (BrdU)-labeled nascent viral genomes and that these genomes accumulate in cytoplasmic factories that are delimited by membranes derived from …


Lineage-Specific Differences Between Human And Simian Immunodeficiency Virus Regulation Of Gp120 Trimer Association And Cd4 Binding, Andrés Finzi, Beatriz Pacheco, Shi-Hua Xiang, Marie Pancera, Alon Herschhorn, Liping Wang, Xing Zeng, Anik Desormeaux, Peter D. Kwong, Joseph Sodroski Jan 2012

Lineage-Specific Differences Between Human And Simian Immunodeficiency Virus Regulation Of Gp120 Trimer Association And Cd4 Binding, Andrés Finzi, Beatriz Pacheco, Shi-Hua Xiang, Marie Pancera, Alon Herschhorn, Liping Wang, Xing Zeng, Anik Desormeaux, Peter D. Kwong, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Metastable conformations of the gp120 and gp41 envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) must be maintained in the unliganded state of the envelope glycoprotein trimer. Binding of gp120 to the primary receptor, CD4, triggers the transition to an open conformation of the trimer, promoting interaction with the CCR5 chemokine receptor and ultimately leading to gp41-mediated virus-cell membrane fusion and entry. Topological layers in the gp120 inner domain contribute to gp120-trimer association in the unliganded state and to CD4 binding. Here we describe similarities and differences between HIV-1 and SIVmac gp120. In both …


Subunit Organization Of The Membrane-Bound Hiv-1 Envelope Glycoprotein Trimer, Youdong Mao, Liping Wang, Christopher Gu, Alon Herschhorn, Shi-Hua Xiang, Hillel Haim, Xinzhen Yang, Joseph Sodroski Jan 2012

Subunit Organization Of The Membrane-Bound Hiv-1 Envelope Glycoprotein Trimer, Youdong Mao, Liping Wang, Christopher Gu, Alon Herschhorn, Shi-Hua Xiang, Hillel Haim, Xinzhen Yang, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

The trimeric human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) spike is a molecular machine that mediates virus entry into host cells and is the sole target for virus-neutralizing antibodies. The mature Env spike results from cleavage of a trimeric gp160 precursor into three gp120 and three gp41 subunits. Here we describe an ~11-Å cryo-EM structure of the trimeric HIV-1 Env precursor in its unliganded state. The three gp120 and three gp41 subunits form a cage-like structure with an interior void surrounding the trimer axis. Interprotomer contacts are limited to the gp41 transmembrane region, the torus-like gp41 ectodomain, and …


Comparative Analysis Of The Fusion Efficiency Elicited By The Envelope Glycoprotein V1–V5 Regions Derived From Human Immunodeficiency Virus Type 1 Transmitted Perinatally, Hongyan Guo, Levon Abrahamyan, Chang Liu, Mackenzie Waltke, Yunqi Geng, Qimin Chen, Charles Wood, Xiaohong Kong Jan 2012

Comparative Analysis Of The Fusion Efficiency Elicited By The Envelope Glycoprotein V1–V5 Regions Derived From Human Immunodeficiency Virus Type 1 Transmitted Perinatally, Hongyan Guo, Levon Abrahamyan, Chang Liu, Mackenzie Waltke, Yunqi Geng, Qimin Chen, Charles Wood, Xiaohong Kong

Nebraska Center for Virology: Faculty Publications

Understanding the properties of viruses preferentially establishing infection during perinatal transmission of human immunodeficiency virus type 1 (HIV-1) is critical for the development of effective measures to prevent transmission. A previous study demonstrated that the newly transmitted viruses (in infants) of chronically infected mother–infant pairs (MIPs) were fitter in terms of growth, which was imparted by their envelope (Env) glycoprotein V1–V5 regions, than those in the corresponding chronically infected mothers. In order to investigate whether the higher fitness of transmitted viruses was conferred by their higher entry efficiency directed by the V1–V5 regions during perinatal transmission, the fusogenicity of Env …


Antibody Responses To Lytic And Latent Human Herpesvirus 8 Antigens Among Hiv-Infected Patients In Central China, Tiejun Zhang, Na He, Yingying Ding, Qingwu Jiang, Charles Wood Jan 2012

Antibody Responses To Lytic And Latent Human Herpesvirus 8 Antigens Among Hiv-Infected Patients In Central China, Tiejun Zhang, Na He, Yingying Ding, Qingwu Jiang, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 8 (HHV8) is an important opportunistic infection of HIV/AIDS. However, very little is known about antibody seropositivities to HHV8 lytic and latent antigens among HIVinfected patients in China. Therefore, a cross-sectional study was conducted to explore HHV8 serostatus among 316 HIV-infected patients in a rural area of central China. The antibody seropositivity to HHV8 ORF65 (lytic) and LANA (latent) antigens was 12.7% and 10.4%, respectively. Patients who were naïve to antiretroviral therapy (ART) were more likely to be seropositive for antibodies to ORF65 (OR: 3.79; 95% CI: 1.71–8.42) and LANA (OR: 3.77; 95% CI: 1.55–9.14) than patients receiving …


Heme Oxygenase-1 Regulates The Immune Response To Influenza Virus Infection And Vaccination In Aged Mice, Nathan W. Cummins, Eric A. Weaver, Shannon M. May, Anthony J. Croatt, Oded Foreman, Richard B. Kennedy, Gregory A. Polan, Michael A. Barry, Karl A. Nath, Andrew D. Badley Jan 2012

Heme Oxygenase-1 Regulates The Immune Response To Influenza Virus Infection And Vaccination In Aged Mice, Nathan W. Cummins, Eric A. Weaver, Shannon M. May, Anthony J. Croatt, Oded Foreman, Richard B. Kennedy, Gregory A. Polan, Michael A. Barry, Karl A. Nath, Andrew D. Badley

Nebraska Center for Virology: Faculty Publications

Underlying mechanisms of individual variation in severity of influenza infection and response to vaccination are poorly understood. We investigated the effect of reduced heme oxygenase-1 (HO-1) expression on vaccine response and outcome of influenza infection. HO-1-deficient and wild-type (WT) mice (kingdom, Animalia; phylum, Chordata; genus/species, Mus musculus) were infected with influenza virus A/PR/8/34 with or without prior vaccination with an adenoviral-based influenza vaccine. A genome-wide association study evaluated the expression of single-nucleotide polymorphisms (SNPs) in the HO-1 gene and the response to influenza vaccination in healthy humans. HO-1-deficient mice had decreased survival after influenza infection compared to WT mice (median …


Thoughts On Quorum Sensing And Fungal Dimorphism, Kenneth W. Nickerson, Audrey L. Atkin, Jessica C. Hargarten, Ruvini U. Pathirana, Sahar Hasim Jan 2012

Thoughts On Quorum Sensing And Fungal Dimorphism, Kenneth W. Nickerson, Audrey L. Atkin, Jessica C. Hargarten, Ruvini U. Pathirana, Sahar Hasim

Papers in Microbiology

Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications …