Veterinary Pathology and Pathobiology Commons^™

Rhodotorula Minuta Fungemia In A Ewe Lamb, C G. Chitko-Mckown, K A. Leymaster, M. P. Heaton, D D. Griffin, J K. Veatch, S A. Jones, M. L. Clawson

School of Veterinary and Biomedical Sciences: Faculty Publications

An 8-month-old crossbred ewe, normal upon physical examination, was humanely euthanized for tissue collection. After approximately 3 weeks in tissue culture, fungi began budding out of cells obtained from the choroid plexus. After an additional 3 weeks, budding was observed in kidney cell cultures and eventually in monocyte cultures as well. Serum from the lamb was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for Aspergillus, Blastomyces, Coccidioidomycosis and Histoplasmosis. DNA was isolated from fungi collected from tissue culture supernatants and used in a set of pan-fungal PCR assays with DNA …

Posttranslational Modification Of Vesicular Stomatitis Virus Glycoprotein, But Not Jnk Inhibition, Is The Antiviral Mechanism Of Sp600125, Sabrina Marozin, Jennifer Altomonte, Sibylle Apfel, Phat X. Dinh, Enrico De Toni, Antonia Rizzani, Andreas Nüssler, Nobuyuki Kato, Roland M. Schmid, Asit K. Pattnaik, Oliver Eberta

School of Veterinary and Biomedical Sciences: Faculty Publications

Vesicular stomatitis virus (VSV), a negative-sense single-stranded-RNA rhabdovirus, is an extremely promising oncolytic agent for cancer treatment. Since oncolytic virotherapy is moving closer to clinical application, potentially synergistic combinations of oncolytic viruses and molecularly targeted antitumor agents are becoming a meaningful strategy for cancer treatment. Mitogenactivated protein kinase (MAPK) inhibitors have been shown to impair liver cell proliferation and tumor development, suggesting their potential use as therapeutic agents for hepatocellular carcinoma (HCC). In this work, we show that the impairment of MAPK in vitro did not interfere with the oncolytic properties of VSV in HCC cell lines. Moreover, the administration …

Identification Of Amino Acid Residues Important For Anti-Ifn Activity Of Porcine Reproductive And Respiratory Syndrome Virus Non-Structural Protein 1, Lalit Beura, Sakthivel Subramaniam, Hiep Vu, Byungjoon Kwon, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

The non-structural protein 1 (nsp1) of porcine reproductive and respiratory syndrome virus is partly responsible for inhibition of type I interferon (IFN) response by the infected host. By performing alanine-scanning mutagenesis, we have identified amino acid residues in nsp1α and nsp1β~ (the proteolytic products of nsp1) that when substituted with alanine(s) exhibited significant relief of IFNsuppression. A mutant virus (16-SA, in which residues 16-20 of nsp1β were substituted with alanines) encoding mutant nsp1β recovered from infectious cDNA clone was shown to be attenuated for growth in vitro and induced significantly higher amount of type I IFN transcripts in infected macrophages. …

Glycosyl-Phosphatidylinositol (Gpi)-Anchored Membrane Association Of The Porcine Reproductive And Respiratory Syndrome Virus Gp4 Glycoprotein And Its Co-Localization With Cd163 In Lipid Rafts, Yijun Du, Asit K. Pattnaik, Cheng Song, Dongwan Yoo, Gang Li

School of Veterinary and Biomedical Sciences: Faculty Publications

The porcine reproductive and respiratory syndrome virus (PRRSV) glycoprotein 4 (GP4) resembles a typical type I membrane protein in its structure but lacks a hydrophilic tail at the C-terminus, suggesting that GP4 may be a lipid-anchored membrane protein. Using the human decay-accelerating factor (DAF; CD55), a known glycosyl-phosphatidylinositol (GPI) lipid-anchored protein, chimeric constructs were made to substitute the GPI-anchor domain of DAF with the putative lipid-anchor domain of GP4, and their membrane association and lipase cleavage were determined in cells. The DAF-GP4 fusion protein was transported to the plasma membrane and was cleaved by phosphatidylinositol-specific phospholipase C (PI-PLC), indicating that …

A Single Amino Acid Change Resulting In Loss Of Fluorescence Of Egfp In A Viral Fusion Protein Confers Fitness And Growth Advantage To The Recombinant Vesicular Stomatitis Virus, Phat X. Dinh, Debasis Panda, Phani B. Das, Subash C. Das, Anshuman Das, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Using a recombinant vesicular stomatitis virus encoding eGFP fused in-frame with an essential viral replication protein, the phosphoprotein P, we show that during passage in culture, the virus mutates the nucleotide C289 within eGFP of the fusion protein PeGFP to A or T, resulting in R97S/C amino acid substitution and loss of fluorescence. The resultant non-fluorescent virus exhibits increased fitness and growth advantage over its fluorescent counterpart. The growth advantage of the non-fluorescent virus appears to be due to increased transcription and replication activities of the PeGFP protein carrying the R97S/C substitution. Further, our results show that the R97S/C mutation …

Amino Acid Residues In The Non-Structural Protein 1 Of Porcine Reproductive And Respiratory Syndrome Virus Involved In Down-Regulation Of Tnf-Cx Expression In Vitro And Attenuation In Vivo, Sakthivel Subramaniam, Lalit Beura, Byungjoon Kwon, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) suppresses tumor necrosis factor-alpha (TNF-α) production at both transcriptional and post-transcriptional levels by its non-structural proteins 1α and 1β (Nsp1α and Nsp1β). To identifY the amino acid residues responsible for this activity, we generated several alanine substitution mutants of Nsp1α and Nsp1β. Examination of the mutant proteins revealed that Nsp1α residues Gly90, Asn91 , Arg97, Argl 00 and Arg124 were necessary for TNF-α promoter suppression, whereas several amino acids spanning the entire Nsp1β ~ were found to be required for this activity. Two mutant viruses, with mutations at Nsp1α Gly90 or Nsp1β residues …

Fusion Of A Fluorescent Protein To The Pul25 Minor Capsid Protein Of Pseudorabies Virus Allows Live-Cell Capsid Imaging With Negligible Impact On Infection, Kevin P. Bohannon, Patricia J. Sollars, Gary E. Pickard, Gregory A. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

In order to resolve the location and activity of submicroscopic viruses in living cells, viral proteins are often fused to fluorescent proteins (FPs) and visualized by microscopy. In this study, we describe the fusion of FPs to three proteins of pseudorabies virus (PRV) that allowed imaging of capsids in living cells. Included in this study are the first recombinant PRV strains expressing FP–pUL25 fusions based on a design applied to herpes simplex virus type 1 by Homa and colleagues. The properties of each reporter virus were compared in both in vitro and in vivo infection models. PRV strains expressing FP–pUL25 …

Staphylococcal Response To Oxidative Stress, Rosmarie Gaupp, Nagender Ledala, Greg A. Somerville

School of Veterinary and Biomedical Sciences: Faculty Publications

Staphylococci are a versatile genus of bacteria that are capable of causing acute and chronic infections in diverse host species. The success of staphylococci as pathogens is due in part to their ability to mitigate endogenous and exogenous oxidative and nitrosative stress. Endogenous oxidative stress is a consequence of life in an aerobic environment; whereas, exogenous osidative and nitrosative stress are often due to the bacteria's interaction with host immune systems. To overcome the deleterious effects of oxidative and nitrosative stress, staphylococci have evolved protection, detoxification, and repair mechanisms that are controlled by a network of regulators. In this review, …

Koutango: Under Reported Arboviral Disease In West Africa, Jaime Matias De Araujo Lobo

LSU Doctoral Dissertations

Arthropod-borne viruses (arboviruses) are among the most common agents of human febrile illnesses worldwide. As crucially important emerging pathogens, they have caused multiple, notable epidemics of human disease and unnoticed epizootics over recent decades. Despite the public health relevance, very little is known about the geographic distribution of the agents and vectors, relative impact, and risk factors associated to the arboviral infection in many regions of the world and in the tropics in particular. Presented in this dissertation is an experimental study that explores the serology screening of serum samples from 151 patients whom were diagnosed with undifferentiated febrile illness …

Development And Characterization Of A Murine Model Of Rickettsia Parkeri Rickettsiosis, Britton Grasperge

LSU Doctoral Dissertations

Rickettsia parkeri, a member of the spotted fever group of Rickettsia, is the agent of an emerging rickettsiosis in the southeastern United States and South America. Despite increased recognition of human cases, limited information is available regarding infection of invertebrate and vertebrate hosts for this emerging tick-borne disease. Towards development of a viable transmission model and to further characterize the pathology associated with R. parkeri infection, inbred mouse strains (A/J, Balb/C, C3H/HeJ, and C3H/HeN) were intravenously and intradermally inoculated with R. parkeri. The C3H/HeJ strain of mice were identified as the most susceptible to R. parkeri infection and were found …

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 …

Cellular Poly(C) Binding Proteins 1 And 2 Interact With Porcine Reproductive And Respiratory Syndrome Virus Nonstructural Protein 1Β And Support Viral Replication, Lalit Beura, Phat X. Dinh, Fernando A. Osorio, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine results in substantial economic losses to the swine industry worldwide. Identification of cellular factors involved in PRRSV life cycle not only will enable a better understanding of virus biology but also has the potential for the development of antiviral therapeutics. The PRRSV nonstructural protein 1 (nsp1) has been shown to be involved in at least two important functions in the infected hosts: (i) mediation of viral subgenomic (sg) mRNA transcription and (ii) suppression of the host’s innate immune response mechanisms. To further our understanding of the role of the viral …

Genome Of Mycoplasma Haemofelis, Unraveling Its Strategies For Survival And Persistence, Andrea P. Santos, Ana Ms Guimaraes, Naila C. Do Nascimento, Phillip J. Sanmiguel, Samuel W. Martin, Joanne Messick

Department of Comparative Pathobiology Faculty Publications

Mycoplasma haemofelis is a mycoplasmal pathogen (hemoplasma) that attaches to the host’s erythrocytes. Distributed worldwide, it has a significant impact on the health of cats causing acute disease and, despite treatment, establishing chronic infection. It might also have a role as a zoonotic agent, especially in immunocompromised patients. Whole genome sequencing and analyses of M. haemofelis strain Ohio2 was undertaken as a step toward understanding its survival and persistence. Metabolic pathways are reduced, relying on the host to supply many of the nutrients and metabolites needed for survival. M. haemofelis must import glucose for ATP generation and ribose derivates for …

Antagonistic Effects Of Cellular Poly(C) Binding Proteins On Vesicular Stomatitis Virus Gene Expression, Phat X. Dinh, Lalit Beura, Debasis Panda, Anshuman Das, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Immunoprecipitation and subsequent mass spectrometry analysis of the cellular proteins from cells expressing the vesicular stomatitis virus (VSV) P protein identified the poly(C) binding protein 2 (PCBP2) as one of the P protein-interacting proteins. To investigate the role of PCBP2 in the viral life cycle, we examined the effects of depletion or overexpression of this protein on VSV growth. Small interfering RNA-mediated silencing of PCBP2 promoted VSV replication. Conversely, overexpression of PCBP2 in transfected cells suppressed VSV growth. Further studies revealed that PCBP2 negatively regulates overall viral mRNA accumulation and subsequent genome replication. Coimmunoprecipitation and immunofluorescence microscopic studies showed that …

Acute Fatty Liver Of Pregnancy: An Update On Mechanisms, Sathish Kumar Natarajan, Kavitha R. Thangaraj, Ashish Goel, C. E. Eapen, K. A. Balasubramanian, Anup Ramachandran

School of Veterinary and Biomedical Sciences: Faculty Publications

Acute fatty liver of pregnancy (AFLP), characterized by hepatic microvesicular steatosis, is a sudden catastrophic illness occurring almost exclusively in the third trimester of pregnancy. Defective fatty acid oxidation in the fetus has been shown to be associated with this disease. Since the placenta has the same genetic makeup as the fetus and as AFLP patients generally recover following delivery, we hypothesized that the placenta might be involved in pathogenesis of this disease. In an animal model of hepatic microvesicular steatosis (using sodium valproate), we found that microvesicular steatosis results in mitochondrial structural alterations and oxidative stress in subcellular organelles …

Glutaredoxin 2 Prevents H2o2-Induced Cell Apoptosis By Protecting Complex I Activity In The Mitochondria, Hongli Wu, Kuiyi Xing, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Glutaredoxin 2 (Grx2) belongs to the oxidoreductase family and is an isozyme of glutaredoxin 1 (Grx1) present in the mitochondria, however its function is not well understood. The purpose of this study is to evaluate the potential anti-apoptotic function of Grx2 by examining its ability to protect complex I in the mitochondrial electron transport system using human lens epithelial cells as a model. We found that cells treated with 200 μM hydrogen peroxide (H2O2) for 24 h exhibited decreased viability and became apoptotic with corresponding Bax up-regulation, Bcl-2 down-regulation, caspase 3 activation and mitochondrial cytochrome c leakage. Grx2 over-expression (OE) …

Regulation Of Cytosolic Phospholipase A2 (Cpla2) And Its Association With Cell Proliferation In Human Lens Epithelial Cells, Yin Wang, Kui-Yi Xing, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. To investigate the molecular mechanism for cytosolic phospholipase A2 (cPLA2) regulation and its association to platelet-derived growth factor (PDGF)-induced cell proliferation.

METHODS. cPLA2 was examined using human lens epithelial (HLE) B3 cells. Reactive oxygen species (ROS) generation induced by PDGF was analyzed by luminescence assay. Cell proliferation was measured by cell counting and by BrdU assay. Human cPLA2 gene was cloned via RT-PCR followed by sitedirected mutagenesis to construct HLE B3 cells expressing either inactive cPLA2 enzyme with S228A mutation (S228A), or cPLA2 truncated at the calcium-binding C2 domain (C2D). Activity of cPLA2 was measured by arachidonic acid (AA) …

Immune Evasion Of Porcine Reproductive And Respiratory Syndrome Virus Through Glycan Shielding Involves Both Glycoprotein 5 As Well As Glycoprotein 3, Hiep Vu, Byungjoon Kwon, Kyoung-Jin Yoon, William W. Laegreid, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Passive administration of porcine reproductive and respiratory syndrome virus (PRRSV) neutralizing antibodies (NAbs) can effectively protect pigs against PRRSV infection. However, after PRRSV infection, pigs typically develop a weak and deferred NAb response. One major reason for such a meager NAb response is the phenomenon of glycan shielding involving GP5, a major glycoprotein carrying one major neutralizing epitope. We describe here a type II PRRSV field isolate (PRRSV-01) that is highly susceptible to neutralization and induces an atypically rapid, robust NAb response in vivo. Sequence analysis shows that PRRSV-01 lacks two N-glycosylation sites, normally present in wild-type (wt) PRRSV strains, …

Complete Genome Sequence Of Mycoplasma Suis And Insights Into Its Biology And Adaption To An Erythrocyte Niche, Ana Ms Guimaraes, Andrea P. Santos, Phillip Sanmiguel, Thomas Walter, Jorge Timenetsky, Joanne Messick

Department of Comparative Pathobiology Faculty Publications

Mycoplasma suis, the causative agent of porcine infectious anemia, has never been cultured in vitro and mechanisms by which it causes disease are poorly understood. Thus, the objective herein was to use whole genome sequencing and analysis of M. suis to define pathogenicity mechanisms and biochemical pathways. M. suis was harvested from the blood of an experimentally infected pig. Following DNA extraction and construction of a paired end library, whole-genome sequencing was performed using GS-FLX (454) and Titanium chemistry. Reads on paired-end constructs were assembled using GS De Novo Assembler and gaps closed by primer walking; assembly was validated by …

Molecular Structures Of Prrsv That Contribute To Prrsv Protective Immunity, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

One of the objectives of the proposal is to delineate the regions of the two glycoproteins (GP2 and GP4) of PRRSV that interact with CD163. Other objectives of the proposal are to generate antibodies to these small regions of the glycoproteins as well as to the full-length proteins for future studies to determine if any of these antibodies possess PRRSV neutralizing activity.

To carry out the studies in the proposed objectives, we generated a series of mutants of GP2 as well as GP4 proteins in which various regions were specifically removed by manipulating the plasmids encoding these proteins. We then …