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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, …

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 …

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 …

A Dysfunctional Tricarboxylic Acid Cycle Enhances Fitness Of Staphylococcus Epidermidis During Β-Lactam Stress, Vinai Chittenzham Thomas, Lauren Kinkhead, Ashley Janssen, Carolyn Schaeffer, Keith Woods, Jill Lindgren, Johnathan Peaster, Sujata Chaudhari, Marat Sadykov, Joselyn Jones, Sameh Mohamadi Abdelghani, Matthew Zimmerman, Kenneth W. Bayles, Greg Somerville, Paul Fey

School of Veterinary and Biomedical Sciences: Faculty Publications

A recent controversial hypothesis suggested that the bactericidal action of antibiotics is due to the generation of endogenous reactive oxygen species (ROS), a process requiring the citric acid cycle (tricarboxylic acid [TCA] cycle). To test this hypothesis, we assessed the ability of oxacillin to induce ROS production and cell death in Staphylococcus epidermidis strain 1457 and an isogenic citric acid cycle mutant. Our results confirm a contributory role for TCA-dependent ROS in enhancing susceptibility of S. epidermidis toward β-lactam antibiotics and also revealed a propensity for clinical isolates to accumulate TCA cycle dysfunctions presumably as a way to tolerate these …

Manipulation Of Cellular Processing Bodies And Their Constituents By Viruses, Asit K. Pattnaik, Phat X. Dinh

School of Veterinary and Biomedical Sciences: Faculty Publications

The processing bodies (PBs) are a form of cytoplasmic aggregates that house the cellular RNA decay machinery as well as many RNA-binding proteins and mRNAs. The PBs are constitutively present in eukaryotic cells and are involved in maintaining cellular homeostasis by regulating RNA metabolism, cell signaling, and survival. Virus infections result in modification of the PBs and their constituents. Many viruses induce compositionally altered PBs, while many others use specific components of the PBs for their replication. PB constituents are also known to restrict virus replication by a variety of mechanisms. Further, continuing studies in this rapidly emerging field of …

Characterization Of A Serologic Marker Candidate For Development Of A Live-Attenuated Diva Vaccine Against Porcine Reproductive And Respiratory Syndrome Virus, Hiep Vu, Byungjoon Kwon, Marcelo De Lima, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

DIVA (differentiating infected from vaccinated animals) vaccines have proven extremely useful for control and eradication of infectious diseases in livestock. We describe here the characterization of a serologic marker epitope, so-called epitope-M201, which can be a potential target for development of a live-attenuated DIVA vaccine against porcine reproductive and respiratory syndrome virus (PRRSV). Epitope-M201 is located at the carboxyl terminus (residues 161-174) of the viral M protein. The epitope is highly immunodominant and well-conserved among type-II PRRSV isolates. Rabbit polyclonal antibodies prepared against this epitope are non-neutralizing; thus, the epitope does not seem to contribute to the protective immunity against …

Trex1 Regulates Lysosomal Biogenesis And Interferon-Independent Activation Of Antiviral Genes, Maroof Hasan, James Koch, Dinesh Rakheja, Asit K. Pattnaik, James Brugarolas, Igor Dozmorov, Beth Levine, Edward K. Wakeland, Min Ae Lee-Kirsch, Nan Yan

School of Veterinary and Biomedical Sciences: Faculty Publications

Innate immune sensing of viral nucleic acids triggers type I interferon (IFN) production, which activates interferon-stimulated genes (ISGs) and directs a multifaceted antiviral response. ISGs can also be activated through IFN-independent pathways, although the precise mechanisms remain elusive. Here we found that the cytosolic exonuclease Trex1 regulates the activation of a subset of ISGs independently of IFN. Both Trex1−/− mouse and TREX1-mutant human cells express high levels of antiviral genes and are refractory to viral infections. The IFN-independent activation of antiviral genes in Trex1−/− cells requires STING, TBK1 and IRF3 and IRF7. We also found that Trex1-deficient cells display expanded …

Influence Of Therapeutic Ceftiofur Treatments Of Feedlot Cattle On Fecal And Hide Prevalences Of Commensal Escherichia Coli Resistant To Expanded-Spectrum Cephalosporins, And Molecular Characterization Of Resistant Isolates, John W. Schmidt, Dee Griffin, Larry A. Kuehn, Dayna M. Brichta-Harhay

School of Veterinary and Biomedical Sciences: Faculty Publications

In the United States, the bla_CMY-2 gene contained within incompatibility type A/C (IncA/C) plasmids is frequently identified in extended-spectrum-cephalosporin-resistant (ESC^r) Escherichia coli strains from both human and cattle sources. Concerns have been raised that therapeutic use of ceftiofur in cattle may increase the prevalence of ESC^r E. coli. We report that herd ESC^r E. coli fecal and hide prevalences throughout the residency of cattle at a feedlot, including during the period of greatest ceftiofur use at the feedlot, were either not significantly different (P≥0.05) or significantly less (Pr E. coli shedding that follows ceftiofur …

Complete Closed Genome Sequences Of Mannheimia Haemolytica Serotypes A1 And A6, Isolated From Cattle, Gregory P. Harhay, Sergey Koren, Adam M. Phillippy, D. Scott Mcvey, Jennifer Kuszak, Michael L. Clawson, Dayna M. Harhay, Michael P. Heaton, Carol G. Chitko-Mckown, Timothy P. L. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

Mannheimia haemolytica is a respiratory pathogen affecting cattle and related ruminants worldwide. M. haemolytica is commonly associated with bovine respiratory disease complex (BRDC), a polymicrobial multifactorial disease.Wepresent the first two complete closed genome sequences of this species, determined using an automated assembly pipeline requiring no manual finishing.

Deep Sequencing And Genome-Wide Analysis Reveals The Expansion Of Microrna Genes In The Gall Midge Mayetiola Destructor, Chitvan Khajuria, Christie E. Williams, Mustapha El Bouhssini, R. Jeff Whitworth, Stephen Richards, Jeffrey J. Stuart, Ming-Shun Chen

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in regulating post transcriptional gene expression. Gall midges encompass a large group of insects that are of economic importance and also possess fascinating biological traits. The gall midge Mayetiola destructor, commonly known as the Hessian fly, is a destructive pest of wheat and model organism for studying gall midge biology and insect – host plant interactions.

Results: In this study, we systematically analyzed miRNAs from the Hessian fly. Deep-sequencing a Hessian fly larval transcriptome led to the identification of 89 miRNA species that are either identical or very …

Development And Evaluation Of A Replicon Particle Vaccine Expressing The E2 Glycoprotein Of Bovine Viral Diarrhea Virus (Bvdv) In Cattle, John Dustin Loy, Jill Gander, Mark Mogler, Ryan Vander Veen, Julia Ridpath, Delbert Hank Harris, Kurt Kamrud

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Bovine viral diarrhea virus is one of the most significant and costly viral pathogens of cattle worldwide. Alphavirus-derived replicon particles have been shown to be safe and highly effective vaccine vectors against a variety of human and veterinary pathogens. Replicon particles are non-propagating, DIVA compatible, and can induce both humoral and cell mediated immune responses. This is the first experiment to demonstrate that Alphavirus-based replicon particles can be utilized in a standard prime/boost vaccination strategy in calves against a commercially significant bovine pathogen.

Findings: Replicon particles that express bovine viral diarrhea virus sub-genotype 1b E2 glycoprotein were …

An Update On Vitamin D: The Role In Chronic Disease, Clinical Practice Implications, And The Current Status Of Nurse Practitioner Knowledge, Sara E. Robertson

DNP Projects

The discovery that a large portion of the United States population is vitamin D deficient, has led to hundreds of studies in the last decade which aim to discover the role of vitamin D in overall health and to determine what clinical consequences occur in a deficient state. The current clinical knowledge regarding vitamin D deficiency is reviewed, including the definition of vitamin D insufficiency and deficiency and its correlation to chronic disease states; the risk factors and epidemiology of vitamin D deficiency; and appropriate clinical screening and treatment of vitamin D deficiency. A research study completed in 2012 to …

Hypoxia-Inducing Factors As Master Regulators Of Stemness Properties And Altered Metabolism Of Cancer- And Metastasis-Initiating Cells., Murielle Mimeault, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Accumulating lines of experimental evidence have revealed that hypoxia-inducible factors, HIF-1α and HIF-2α, are key regulators of the adaptation of cancer- and metastasis-initiating cells and their differentiated progenies to oxygen and nutrient deprivation during cancer progression under normoxic and hypoxic conditions. Particularly, the sustained stimulation of epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), stem cell factor (SCF) receptor KIT, transforming growth factor-β receptors (TGF-βRs) and Notch and their downstream signalling elements such as phosphatidylinositol 3'-kinase (PI3K)/Akt/molecular target of rapamycin (mTOR) may lead to an enhanced activity of HIFs. Moreover, the up-regulation of HIFs in cancer cells may …

Dynein And Dynactin Leverage Their Bivalent Character To Form A High-Affinity Interaction., Amanda E Siglin, Shangjin Sun, Jeffrey K Moore, Sarah Tan, Martin Poenie, James D Lear, Tatyana Polenova, John A Cooper, John C Williams

Department of Biochemistry and Molecular Biology Faculty Papers

Cytoplasmic dynein and dynactin participate in retrograde transport of organelles, checkpoint signaling and cell division. The principal subunits that mediate this interaction are the dynein intermediate chain (IC) and the dynactin p150(Glued); however, the interface and mechanism that regulates this interaction remains poorly defined. Herein, we use multiple methods to show the N-terminus of mammalian dynein IC, residues 10-44, is sufficient for binding p150(Glued). Consistent with this mapping, monoclonal antibodies that antagonize the dynein-dynactin interaction also bind to this region of the IC. Furthermore, double and triple alanine point mutations spanning residues 6 to 19 in the yeast IC homolog, …

Mean Platelet Volume As A Fibrosis Marker In Patients With Chronic Hepatitis C, Hati̇ce Karaman, Çi̇ğdem Karakükcü, Ahmet Karaman, Tuba Kayman, Samet Yalçin, Erdem Arzu Taşdemi̇r, Gökmen Zararsiz, Orhan Kürşat Poyrazoğlu

Turkish Journal of Medical Sciences

We designed this study to evaluate the role of mean platelet volume (MPV) as a fibrosis marker in patients with chronic hepatitis C (CHC). Materials and methods: The study was designed at Kayseri Education and Research Hospital. Ninety-five patients with CHC were enrolled retrospectively into the study. The control group comprised 33 age- and sex-matched healthy individuals. Hepatitis C virus-RNA level, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, prothrombin time (PT), platelet count (PC), serum albumin, histological activity index (HAI), liver fibrosis score (LFS), and MPV were obtained from the patients' files and a computerized database. Results: Statistically significant differences …

Significant Features Of Basal And Maximal Energy Expenditure Parameters In Obese Adults, Emi̇ne Uygur, Kağan Üçok, Abdurrahman Genç, Ümi̇t Şener, Ramazan Uygur, Ahmet Songur

Turkish Journal of Medical Sciences

To compare body composition, resting metabolic rate, and maximal aerobic capacity parameters in obese adults and healthy controls, as well as to investigate the associations among these parameters. Materials and methods: A total of 120 participants, 60 obese participants (30 male, 30 female) with body mass indexes (BMIs) over 30 kg/m^2 and 60 healthy controls (30 male, 30 female) with BMIs of 18-25 kg/m^2, were included in the study. BMI was calculated as body weight divided by the square of the height (kg/m^2). Body fat percentage, total body fat, and lean body mass were established with bioelectric impedance analysis. Resting …

Turning Stealth Liposomes Into Cationic Liposomes For Anticancer Drug Delivery, Vijay Gyanani

University of the Pacific Theses and Dissertations

Targeting the anticancer agents selectively to cancer cells is desirable to improve the efficacy and to reduce the side effects of anticancer therapy. Previously reported passive tumor targeting by PEGylated liposomes (stealth liposomes) have resulted in their higher tumor accumulation. However their interaction with cancer cells has been minimal due to the steric hindrance of the PEG coating. This dissertation reports two approaches to enhance the interaction of stealth liposomes with cancer cells. First, we designed a lipid-hydrazone-PEG conjugate that removes the PEG coating at acidic pH as in the tumor interstitium. However, such a conjugate was highly unstable on …

The Phenotypic Expression Of Usp14 Deficiency Is Dependent Upon Genetic Background, Andrea Gail Marshall

All ETDs from UAB

The ubiquitin proteasome system (UPS) plays a critical role in regulating a diversity of cellular processes that are essential to neuronal function, such as synaptic transmission, axon guidance, and neurite outgrowth. Dysfunctions of the UPS are linked with many neurodegenerative disorders, including motor neuron diseases like spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), although it is not known how UPS dysfunction contributes to disease pathology. The proteasome, an approximate 2.5 megadalton protein complex comprised of a 20S core particle and 19S regulatory particle, is the site of ubiquitin-mediated proteolysis in the cell. Recent studies have linked ubiquitin specific …

Cd5 Regulation Of T Helper Cell Differentiation And Cytokine Signaling, Donald J. Mcguire

All ETDs from UAB

CD5 is expressed on T and B1a cells and is an important regulator of cell survival and activation. Engagement of CD5 promotes cell survival through the activation of the serine threonine kinase CK2. Mice with genetic abrogation of CD5 binding to CK2 (CD5∆CK2bd) exhibited reduced severity of experimental autoimmune encephalomyelitis that was associated with increased activation induced cell death. In addition to inhibiting cell death, CD5 activation of CK2 significantly enhances Th17 differentiation. Loss of CD5-CK2 signaling reduces the generation of Th17 cells despite an unexpected increase in pSTAT3 levels. The mechanisms of CD5's enhancement of Th17 differentiation have not …

Intrinsic And Extrinsic Factors Required For Cd4 T Memory Cell Formation And Function, Sarah B. Mollo

All ETDs from UAB

CD4 T cells are central to the organization of the immune response through the secretion of cytokines that recruit and activate other immune cells. Following infection and pathogen control, the majority of the effector CD4 T cells undergo apoptosis, leaving a subset that persists and gives rise to the memory T cell pool. Upon encountering the same pathogen, memory CD4 T cells respond rapidly, providing enhanced protection from re-infection. What determines which effector CD4 T cells will survive is unclear; however, there are a number of factors both intrinsic to the cell as well as external signals from the environment …

Structure-Function Analysis Of Tyrosyl-Dna Phosphodiesterase I, Evan Comeaux

All ETDs from UAB

Tyrosyl-DNA phosphodiesterase I (Tdp1) functions to remove 3'phospho-DNA adducts, such as eukaryotic DNA Topoisomerase I (Top1) covalently bound to the DNA by a 3'phospho-tyrosyl bond. As member of the Phospholipase D superfamily Tdp1 contains two HxK(n)N motifs, each of which provide a catalytic histidine: one functioning as a nucleophile to bind the 3'phosphate and the other as a general acid/base to hydrolyze Tdp1's 3'phospho-histidyl bond. Mutation of the general acid/base catalytic histidine (Hisgab) to arginine has been implicated in the autosomal recessive neurodegenerative disease SCAN1. Further study of the yeast enzyme revealed that substitution of Hisgab in yeast Tdp1 to …

Tgf-Ss And Erg In Intervertebral Disc Development, Megan Karen Cox

All ETDs from UAB

The intervertebral disc (IVD) is a fibrocartilaginous tissue that acts as a shock absorber between adjacent vertebrae in the spinal column. It is comprised of two parts, the inner jelly-like nucleus pulposus (NP) and the outer more fibrous annulus fibrosus (AF). Most IVD research has focused on the development of the NP, which is derived from condensations of the notochord involving sonic hedgehog (Shh) signaling. In contrast, very little is known about the molecular mechanisms underlying the specific development of the AF of the IVD. The AF is derived from the sclerotome, which is formed by the ventral half of …

An Investigation Of Trem-Like Transcript 2 Expression, Kimberly Anne Thomas

All ETDs from UAB

Acute inflammation is a necessary component for the clearance of pathogens. Cells at the site of infection utilize highly conserved receptors to both recognize microbes and induce the production of pro-inflammatory stimuli. These stimuli set off a chain reaction that includes localized vasodilation, leukocyte infiltration, and tissue destruction, collectively known as inflammation. Tightly controlled, this process is protective, and can compartmentalize the damage to a defined area, but when dysregulated can be catastrophic, inducing chronic inflammation and even death. Families of innate receptors can modulate inflammatory processes, and in doing so, increase or decrease their severity, as well as tailor …

Glioma-Vasculature Interactions, Stacey Watkins

All ETDs from UAB

Malignant gliomas are highly invasive brain tumors, which lack effective treatment options. To date, the standard therapy includes surgical debulking followed by chemotherapy and radiation. Despite efforts to eradicate the disease, the median patient survival time is only 14 months. In an attempt to discover novel therapies, research has focused on understanding the heterogeneous biological mechanisms employed by these cells. Uniquely, they do not metastasize through the vasculature or lymphatics like other solid cancers but alternatively, glioma cells utilize the abluminal surface of the vasculature to guide invasion and migration throughout the brain. The intimate association between glioma cells and …

Hur Regulation In Central Nervous System Disorders, Crystal G. Wheeler

All ETDs from UAB

In inflammatory diseases of the central nervous system (CNS), astrocytes play a major role in the systemic response to disease by either enhancing or limiting the inflammatory response through secretion of growth factors or cytokines. HuR RNA binding protein regulates many genes involved in inflammation. Inflammatory diseases such as brain tumors, Amylotrophic Lateral Sclerosis (ALS), and Multiple Sclerosis (MS), have been linked to HuR, by our laboratory and others. To determine whether astrocytic overexpression of HuR would regulate inflammation in diseases of the CNS, we designed a transgenic mouse in which the HuR gene is overexpressed. In the first study, …

Studies Of Dna Gyrase Activity In Escherichia Coli And Salmonella Enterica Serovar Typhimurium., Nikolay Sergeyevich Rovinskiy

All ETDs from UAB

Gyrase introduces negative supercoils into bacterial DNA. In balance with topoisomerase I, it contributes to the maintenance of constant negative DNA supercoiling. It was shown that in Escherichia coli negative supercoil density of pBR322 plasmid is higher than in Salmonella typhimurium. One of the possible explanations of this phenomenon is a difference of DNA gyrase activity between E. coli and S. typhimurium. We developed in vitro assay of gyrase activity which has shown that DNA gyrases of E. coli and S. typhimurium have the same supercoiling end point, but E. coli gyrase works slightly faster than the S. typhimurium enzyme. …

Role Of Gsk3 In The Immunopathogenesis Of Eae, Amber Rowse

All ETDs from UAB

Lithium, a glycogen synthase kinase 3 (GSK3) inhibitor, ameliorates experimental autoimmune encephalomyelitis (EAE), the murine model of multiple sclerosis (MS) in different mouse models. However, the mechanism of lithium's attenuation of EAE and the role of GSK3 in these processes are currently unknown. IFN-g producing Th1 cells and IL-17-producing Th17 cells are both effector cells in MS and in EAE models. However, relapsing remitting MS patients segregate into Th1 or Th17 serum cytokine signatures and each is differentially responsive to IFN-ß therapy, a first line therapy for MS. Studies in this dissertation revealed a differential effect of lithium on Th1 …

Role Of Endothelial Mannose Residues In Monocyte Adhesion Under Flow, David Wayne Scott

All ETDs from UAB

Atherosclerosis is a chronic inflammatory disease of the vessel wall and underlying cause of most cardiovascular disease. Much is understood about the nature of atherosclerosis development, including contributions from leukocytes that drive the disease process forward. The general process by which leukocytes are trafficked to sites of atherosclerosis development, and sites of inflammation in general, is understood and relies upon endothelial expressed protein adhesion molecules which serve as ligands for cognate leukocyte receptors. While these adhesion molecules share the post-translation modification of N-glycosylation, relatively little is known as to what functional role these modification plays in: i) interactions of leukocytes …

Modulation Of Intrinsic Activity In Sensory Cortex Facilitates Task Performance, Aburahman Elkhetali

All ETDs from UAB

Due to the changing demands of the environment and our behavioral intentions the brain has to adapt in order to produce task appropriate responses. Part of the challenge is the large amount of sensory information received by the brain. Depending on individu-al goals, the brain must select and react to task appropriate stimuli while ignoring other irrelevant sensory input. Since behavioral intentions are dynamic, this requires the re-sponses within the brain to also be dynamic. Cognitive control, exerted by higher centers on sensory cortex allow for selection of task relevant stimuli. In this study we find that intrinsic, non-stimulus driven …

Regulation Of Capsule By Cpsa And Global Regulatory Networks In Streptococcus Pneumoniae Type 2, Kanupriya Gupta

All ETDs from UAB

Streptococcus pneumoniae is a major human pathogen that can reside asymptomatically in the nasopharynx before causing invasive disease by entering systemic sites. This involves regulation of colonization and virulence factors including capsule. cps2A, the first gene of the capsule (cps) locus has been proposed to regulate capsule, however its exact role and mechanism is not well understood. A complete deletion of cps2A resulted in enhanced capsule levels, with no alteration in the transcription levels of cps genes. Complementation of Cps2A restored wild type levels of capsule. Expression of the C-terminal tail alone was able to partially complement the deletion strain, …