Veterinary Pathology and Pathobiology Commons^™

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 …

Glutaredoxin 2 (Grx2) Knockout Increases Sensitivity To Oxidative Stress In Mouse Lens Epithelial Cells, Hongli Wu, Liren Lin, Frank Giblin, Ye-Sheh Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Glutaredoxin belongs to the oxidoreductase family with cytosolic glutaredoxin 1 (Grx1) and mitochondrial gluraredoxin 2 (Grx2) isoforms. Of the two isozymes, the function of Grx2 is not well understood. This paper studied the effect of Grx2 deletion on cellular function using primary lens epithelial cell cultures isolated from Grx2 gene knockout (KO) and wild type (WT) mice. We found that both cell types showed similar growth patterns and morphology, and comparable mitochondrial glutathione pool and complex I activity. Cells with deleted Grx2 did not show affected Grx1 or thioredoxin (Trx) expression but exhibited high sensitivity to oxidative stress. Under treatment …

Mycoplasma Haemocanis – The Canine Hemoplasma And Its Feline Counterpart In The Genomic Era, Naila C. Do Nascimento, Andrea P. Santos, Ana Ms Guimaraes, Phillip J. Sanmiguesl, Joanne Messick

Department of Comparative Pathobiology Faculty Publications

Mycoplasma haemocanis is a hemotrophic mycoplasma (hemoplasma), blood pathogen that may cause acute disease in immunosuppressed or splenectomized dogs. The genome of the strain Illinois, isolated from blood of a naturally infected dog, has been entirely sequenced and annotated to gain a better understanding of the biology of M. haemocanis. Its single circular chromosome has 919 992 bp and a low G + C content (35%), representing a typical mycoplasmal genome. A gene-by-gene comparison against its feline counterpart, M. haemofelis, reveals a very similar composition and architecture with most of the genes having conserved synteny extending over their entire chromosomes …

The Effect Of Infection Order Of Porcine Circovirus Type 2 And Porcine Reproductive And Respiratory Syndrome Virus On Dually Infected Swine Alveolar Macrophages, Yi-Chieh Tsai, Hui-Wen Chang, Chian-Ren Jeng, Tsang L. Lin, Chun-Ming Lin, Cho-Hua Wan, Victor Fei Pang

Department of Comparative Pathobiology Faculty Publications

Abstract Background: Concurrent infection with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) is known as one of the major causes for porcine respiratory disease complex (PRDC). Dual infection with PCV2 and PRRSV is consistently to have more severe clinical presentations and pulmonary lesions than infection with PCV2 alone or PRRSV alone. However, it is not known if dual infections with PCV2 and PRRSV in different infection order may lead to different clinical symptoms in the host. To mimic the possible field conditions, swine alveolar macrophages (AMs) were inoculated with PCV2 and PRRSV in vitro …

Ultraviolet Radiation–Induced Cataract In Mice: The Effect Of Age And The Potential Biochemical Mechanism, Jie Zhang, Hong Yan, Stefan Lofgren, Xiaoli Tian, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. To study the effect of age on the morphologic and biochemical alterations induced by in vivo exposure of ultraviolet radiation (UV).

METHODS. Young and old C57BL/6 mice were exposed to broadband UVBþUVA and euthanized after 2 days. Another batch of UV-exposed young mice was monitored for changes after 1, 2, 4, and 8 days. Age-matched nonexposed mice served as controls. Lens changes were documented in vivo by slit-lamp biomicroscopy and dark field microscopy photographs ex vivo. Lens homogenates were analyzed for glutathione (GSH) level, and the activities of thioredoxin (Trx), thioltransferase (TTase), and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Glutathionylated lens proteins …

Development Of Repressible Systems To Control Gene Expression In Vaccinia Virus, Allison Titong

Master's Theses

Two vaccinia virus (VACV) expression systems that contain elements from the lactose (lac) and the tetracycline (tet) operons of E. coli were developed to repress the expression of a reporter gene, enhanced green fluorescent protein (EGFP), in the presence of tet operon inducers. In the first system, lac and tet operon elements were arranged in a gene circuit, and in the presence of increasing concentrations of a lac operon inducer (isopropyl-β-D-thiogalactoside, IPTG), EGFP expression increased in a dose dependent manner and at high IPTG concentrations, expression reached the same levels as a positive control virus. Importantly, in the …

Melanopsin Mediates Retrograde Visual Signaling In The Retina, Dao-Qi Zhang, Michael A. Belenky, Patricia J. Sollars, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

The canonical flow of visual signals proceeds from outer to inner retina (photoreceptors→bipolar cells→ganglion cells). However, melanopsin-expressing ganglion cells are photosensitive and functional sustained light signaling to retinal dopaminergic interneurons persists in the absence of rods and cones. Here we show that the sustained-type light response of retinal dopamine neurons requires melanopsin and that the response is mediated by AMPA-type glutamate receptors, defining a retrograde retinal visual signaling pathway that fully reverses the usual flow of light signals in retinal circuits.

Recombinant Protein Production In Bacillus Species, Isolation And Methionine Production In Methionine-Producing Microorganisms, Suwat Saengkerdsub

Graduate Theses and Dissertations

Linoleic acid isomerase (LAI) is the enzyme that converts linoleic acid to conjugated linoleic acids (CLAs) which appear to be capable of lowering cancer risk and enhancing immunity. There is an interest in developing commercial processes for the production of single isomers of CLA by biotransformation of LA using microbial cells and enzymes. However, the evaluation of these strains suggest that growth and LA isomerase production levels by these anaerobes are insufficient to support economic commercial production of single CLA isomers. A better alternative is to clone the isomerase gene and to generate new production strains using recombinant technology. Bifidobacterium …

The Presence Of Alpha Interferon At The Time Of Infection Alters The Innate And Adaptive Immune Responses To Porcine Reproductive And Respiratory Syndrome Virus, Susan L. Brockman, Crystal A. Loving, Eric A. Nelson, Laura C. Miller, Tracy L. Nicholson, Karen B. Register, Marvin J. Grubman, Douglas E. Brough, Marcus E. Kehrli Jr

Veterinary and Biomedical Sciences Faculty Publications

Porcine reproductive and respiratory syndrome (PRRS) is one of the most devastating and costly diseases to the swine industry worldwide. Overall, the adaptive immune response to PRRS virus (PRRSV) is weak, which results in delayed elimination of virus from the host and inferior vaccine protection. PRRSV has been shown to induce a meager alpha interferon (IFN-α) response, and we hypothesized that elevated IFN-α levels early in infection would shorten the induction time and increase elements of the adaptive immune response. To test this, we measured both antibody and cell-mediated immunity in pigs after the administration of a nonreplicating human adenovirus …

Development Of A Fluorescent Microsphere Immunoassay For Detection Of Antibodies Against Porcine Reproductive And Respiratory Syndrome Virus Using Oral Fluid Samples As An Alternative To Serum-Based Assays, Robert J. Langenhorst, Steven Lawson, Apisit Kittawornrat, Jeffery J. Zimmerman, Zhi Sun, Yanhua Li, Jane Christopher-Hennings, Eric A. Nelson, Ying Fang

Veterinary and Biomedical Sciences Faculty Publications

For effective disease surveillance, rapid and sensitive assays are needed to detect antibodies developed in response to porcine reproductive and respiratory syndrome virus (PRRSV) infection. In this study, we developed a multiplexed fluorescent microsphere immunoassay (FMIA) for detection of PRRSV-specific antibodies in oral fluid and serum samples. Recombinant nucleocapsid protein (N) and nonstructural protein 7 (nsp7) from both PRRSV genotypes (type I and type II) were used as antigens and covalently coupled to Luminex fluorescent microspheres. Based on an evaluation of 488 oral fluid samples with known serostatus, the oral fluid-based FMIAs achieved >92% sensitivity and 91% specificity. For serum …

Zwitterionic Chitosan Derivative, A New Biocompatible Pharmaceutical Excipient, Prevents Endotoxin-Mediated Cytokine Release, Gaurav Bajaj, William G. Van Alstine, Yoon Yeo

Department of Comparative Pathobiology Faculty Publications

Chitosan is a cationic polymer of natural origin and has been widely explored as a pharmaceutical excipient for a broad range of biomedical applications. While generally considered safe and biocompatible, chitosan has the ability to induce inflammatory reactions, which varies with the physical and chemical properties. We hypothesized that the previously reported zwitterionic chitosan (ZWC) derivative had relatively low pro-inflammatory potential because of the aqueous solubility and reduced amine content. To test this, we compared various chitosans with different aqueous solubilities or primary amine contents with respect to the intraperitoneal (IP) biocompatibility and the propensity to induce proinflammatory cytokine production …

The Role Of Gylcoprotein K (Gk) In The Ocular And Neuropathogenesis Of Herpes Simplex Virus-Type 1 (Hsv-1), Andrew Timothy David

LSU Doctoral Dissertations

Herpes simplex virus type 1 (HSV-1) is a DNA virus that is a ubiquitous pathogen of humans. The hallmark of the HSV-lifecycle is infection of a mucosal surface with spread to sensory neurons where the virus establishes a latent infection with periodic recurrences for the life of the host. The most common course of symptomatic disease with HSV-1 is the typical mucocutaneous lesion that is self-limiting. HSV-1 can also cause acute encephalitis and ocular pathology on reactivation. Both of these manifestations of the disease have severe consequences. Although ocular infection is less frequent, the extensive prevalence of HSV makes it …

Immunization Of West Nile Recombinant Envelope Domain Iii With Equine Cd40 Ligand Protein Vaccine Induced Specific Immune Response In Rabbits And Horses, Shiliang Anthony Liu

LSU Master's Theses

West Nile virus (WNV) is one of several flaviruses known to infect mammalian species, including humans. There were 15,257 horse cases reported in 2002 and 1,086 in 2006 in United States. Recently, significant increases in equine and human cases have been reported in United States. Domain III of the WNV envelope protein binds to cellular receptors, and induces a significant portion of the neutralizing antibody response against the virus. CD40 Ligand (CD40L, CD154) enhances productive interactions between T cells and APC and has been shown to function as a potential adjuvant. In this study, we constructed and expressed a fusion …

Role Of Herpes Simplex Type I Glycoproteins In Entry And Cell-Cell Fusion, Sona Chowdhury

LSU Doctoral Dissertations

Herpes simplex virus type I (HSV-1) is a neurotropic virus that infects primarily mucocutaneous epithelial cells and nervous tissue. Membrane fusion is an important aspect of the HSV-1 lifecycle, that occurs during viral entry (virus-cell fusion), viral spread (cell-to-cell fusion), as well as, during virion morphogenesis (assembly and egress). These membrane fusion steps involve complex interactions between multiple viral glycoproteins and cellular receptors. HSV-1 glycoprotein B (gB) is necessary but not sufficient for membrane fusion events. Despite the fact, that the majority of known hypermorphic mutations which cause extensive virus-induced cell fusion occur within glycoprotein K (gK); yet the role …