Medicine and Health Sciences | Open Access Articles

Reduced Intestinal Colonization Of Adult Beef Cattle By Escherichia Coli O157:H7 Tir Deletion And Nalidixic-Acid-Resistant Mutants Lacking Flagellar Expression, Gustavo Bretschneider, Emil M. Berberov, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

The importance of the Escherichia coli O157:H7 translocated intimin receptor (Tir) protein in intestinal colonization and the effect of infection with Tir⁺ strains on protection against subsequent challenge was studied in adult beef cattle. Cattle were orally inoculated (C1) with a Shiga toxin-2⁺+ E. coli O157:H7 strain that was Tir⁺ or Tir^-, and 42 days later were re-challenged (C2) with the nalidixic acid (Nal) ^R parent strain to test whether prior infection had any effect on fecal shedding. During the first 14 days post-C1, the Nal^S wildtype (WT) strain was shed at significantly …

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Porcine Intestinal Epithelial Cell Lines As A New In Vitro Model For Studying Adherence And Pathogenesis Of Enterotoxigenic Escherichia Coli, Seung Y. Koh, Sajan George, Volker Brozel, Rodney A. Moxley, David H. Francis, Radhey Kaushik

School of Veterinary and Biomedical Sciences: Faculty Publications

Enterotoxigenic Escherichia coli (ETEC) infections result in large economic losses in the swine industry worldwide. The organism causes diarrhea by adhering to and colonizing enterocytes in the small intestines. While much progress has been made in understanding the pathogenesis of ETEC, no homologous intestinal epithelial cultures suitable for studying porcine ETEC pathogenesis have been described prior to this report. In the current study, we investigated the adherence of various porcine ETEC strains to two porcine (IPEC-1 and IPEC-J2) and one human (INT-407) small intestinal epithelial cell lines. Each cell line was assessed for its ability to support the adherence of …

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Stable Cell Lines Expressing High Levels Of The Herpes Simplex Virus Type 1 Lat Are Refractory To Caspase 3 Activation And Dna Laddering Following Cold Shock Induced Apoptosis, Dale Carpenter, Chinhui Hsiang, Donald J. Brown, Ling Jin, Nelson Osorio, Lbachir Benmohamed, Clinton J. Jones, Steven L. Wechsler

School of Veterinary and Biomedical Sciences: Faculty Publications

The herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) gene’s anti-apoptosis activity plays a central, but not fully elucidated, role in enhancing the virus’s reactivation phenotype. In transient transfection experiments, LAT increases cell survival following an apoptotic insult in the absence of other HSV-1 genes. However, the high background of untransfected cells has made it difficult to demonstrate that LAT inhibits specific apoptotic factors such as caspases. Here we report that, in mouse neuroblastoma cell lines (C1300) stably expressing high levels of LAT, cold shock induced apoptosis was blocked as judged by increased survival, protection against DNA fragmentation …

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Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

A small number (<2%) of mammalian retinal ganglion cells express the photopigment melanopsin and are intrinsically photosensitive (ipRGCs). Light depolarizes ipRGCs and increases intracellular calcium levels ( [Ca²⁺]_i) but the signaling cascades underlying these responses have yet to be elucidated. To facilitate physiological studies on these rare photoreceptors, highly enriched ipRGC cultures from neonatal rats were generated using anti-melanopsin-mediated plate adhesion (immunopanning). This novel approach enabled experiments on isolated ipRGCs, eliminating the potential confounding influence of rod/cone-driven input. Light induced a rise in [Ca²⁺]_i (monitored using fura-2 imaging) in the immunopanned ipRGCs and the source of this Ca²⁺ signal was investigated. The Ca²⁺ responses were inhibited by 2-aminoethoxydiphenyl borate, SKF-96365 (1–2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole), flufenamic acid, …

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Differences In Virulence Among Escherichia Coli O157:H7 Strains Isolated From Humans During Disease Outbreaks And From Healthy Cattle, Diane R. Baker, Rodney A. Moxley, Mike B. Steele, Jeffrey T. Lejeune, Jane Christopher-Hennings, Ding-Geng Chen, Philip R. Hardwidge, David H. Francis

School of Veterinary and Biomedical Sciences: Faculty Publications

Escherichia coli O157:H7 causes life-threatening outbreaks of diarrhea, hemorrhagic colitis, and hemolyticuremic syndrome in humans and significant economic loss in agriculture and could be a potential agent of bioterrorism. Although the prevalence of E. coli O157:H7 in cattle and other species with which humans have frequent contact is high, human infections are relatively uncommon, despite a low infectious dose. A plausible explanation for the low disease incidence is the possibility that not all strains are virulent in humans. If there are substantial differences in virulence among strains in nature, then human disease may select for high virulence. We used a …

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Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

PRRSV, the causative agent of PRRS is of major economic significance to the pork industry in the USA and around the world. Current commercial vaccine does not provide adequate protection against PRRSV outbreaks. Therefore, there is an urgent need for development of more efficacious vaccine to combat PRRS. Our previous studies have suggested that (i) induction of neutralizing antibody response is an important correlate of evaluating the efficacy of a vaccine; (ii) neutralizing antibodies can be enhanced by hypoglycosylation of the major surface glycoprotein (GP5). While it is known that GP5 plays a prominent role in neutralizing antibody induction, it …

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Otk18, A Zinc-Finger Protein, Regulates Human Immunodeficiency Virus Type 1 Long Terminal Repeat Through Two Distinct Regulatory Regions, Masahide Horiba, Lindsey B. Martinez, James L. Buescher, Sinji Sato, Jenae Limoges, Yunquan Jiang, Clinton J. Jones, Tsuneya Ikezu

School of Veterinary and Biomedical Sciences: Faculty Publications

It has previously been shown by our laboratory that OTK18, a human immunodeficiency virus (HIV)-inducible zinc-finger protein, reduces progeny-virion production in infected human macrophages. OTK18 antiviral activity is mediated through suppression of Tat-induced HIV-1 long terminal repeat (LTR) promoter activity. Through the use of LTR scanning mutant vectors, the specific regions responsible for OTK18-mediated LTR suppression have been defined. Two different LTR regions were identifi ed as potential OTK18-binding sites by an enhanced DNA–transcription factor ELISA system; the negative-regulatory element (NRE) at –255/–238 and the Ets-binding site (EBS) at –150/–139 in the LTR. In addition, deletion of the EBS in …

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Isotype-Specific Antibody Responses Against Escherichia Coli O157:H7 Locus Of Enterocyte Effacement Proteins In Adult Beef Cattle Following Experimental Infection, G. Bretschneider, E. M. Berberov, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

Escherichia coli O157:H7 is an important food-borne pathogen and cause of hemorrhagic colitis and hemolytic uremic syndrome in humans. Cattle are an important reservoir of E. coli O157:H7, in which the organism colonizes the intestinal tract and is shed in the feces. Vaccination of cattle has significant potential as a pre-harvest intervention strategy for E. coli O157:H7; however, basic information about the bovine immune responses to important bacterial colonization factors resulting from infection has not been reported. The serum and fecal IgG and IgA antibody responses of adult cattle to E. coli O157:H7 intimin, translocated intimin receptor (Tir), E. coli …

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Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Low molecular weight protein tyrosine phosphatase (LMW-PTP) was cloned from human lens epithelial B3 cells (HLE B3) and the recombinant enzyme was purified to homogeneity. The pure enzyme reacted positively with anti-LMW-PTP antibody, displayed tyrosine-specific phosphatase activity and was extremely sensitive to H2O2. The inactivated LMW-PTP could be regenerated by thioltransferase (TTase)/GSH system as demonstrated by both activity assay and by mass spectrometry (MS). The MS study also showed that an intramolecular disulfide bond was formed between C13 and C18 at the active site, and was reduced by the TTase/GSH system. The putative role of LMW-PTP in regulating platelet derived …

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The Infected Cell Protein 0 Encoded By Bovine Herpesvirus 1 (Bicp0) Induces Degradation Of Interferon Response Factor 3 And, Consequently, Inhibits Beta Interferon Promoter Activity, Kazima Saira, You Zhou, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

The ICP0 protein (bICP0) encoded by bovine herpesvirus 1 is the major viral regulatory protein because it stimulates all viral promoters and, consequently, productive infection. Like other ICP0 analogues encoded by Alphaherpesvirinae subfamily members, bICP0 contains a zinc RING finger near its amino terminus that is necessary for activating transcription, regulating subcellular localization, and inhibiting interferon-dependent transcription. In this study, we discovered that sequences near the C terminus, and the zinc RING finger, are necessary for inhibiting the human beta interferon (IFN- β) promoter. In contrast to herpes simplex virus type 1-encoded ICP0, bICP0 reduces interferon response factor 3 (IRF3), …

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Localization Of Period 1 Mrna In The Ruminant Oocyte And Investigations Of Its Role In Ovarian Function, R. A. Cushman, M. F. Allan, S. A. Jones, Gary P. Rupp, S. E. Echternkamp

School of Veterinary and Biomedical Sciences: Faculty Publications

The clock gene Period 1 (Per1) may be a prolificacy gene, because it localized to the mouse oocyte and Per1-null drosophila shed fewer eggs. Because Per1 mapped to a region of mouse chromosome 11 syntenic to bovine chromosome 19 where a quantitative trait loci (QTL) for ovulation rate existed, we hypothesized that Per1 influenced folliculogenesis and ovulation rate in ruminants. Ovarian cortex was collected at slaughter on days 5, 12, 15, 17, and 20 after estrus for real-time RT-PCR evaluation of Per1mRNAexpression in Dorset (n = 18), Romanov (n = 10), Romanov/Dorset (n = 21), and Composite …

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Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …

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Full-Text Articles in Medicine and Health Sciences

Reduced Intestinal Colonization Of Adult Beef Cattle By Escherichia Coli O157:H7 Tir Deletion And Nalidixic-Acid-Resistant Mutants Lacking Flagellar Expression, Gustavo Bretschneider, Emil M. Berberov, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine Intestinal Epithelial Cell Lines As A New In Vitro Model For Studying Adherence And Pathogenesis Of Enterotoxigenic Escherichia Coli, Seung Y. Koh, Sajan George, Volker Brozel, Rodney A. Moxley, David H. Francis, Radhey Kaushik

School of Veterinary and Biomedical Sciences: Faculty Publications

School of Veterinary and Biomedical Sciences: Faculty Publications

Light-Evoked Calcium Responses Of Isolated Melanopsin- Expressing Retinal Ganglion Cells, Andrew T. E. Hartwick, Jayne R. Bramley, Jianing Yu, Kelly T. Stevens, Charles N. Allen, William H. Baldridge, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Differences In Virulence Among Escherichia Coli O157:H7 Strains Isolated From Humans During Disease Outbreaks And From Healthy Cattle, Diane R. Baker, Rodney A. Moxley, Mike B. Steele, Jeffrey T. Lejeune, Jane Christopher-Hennings, Ding-Geng Chen, Philip R. Hardwidge, David H. Francis

School of Veterinary and Biomedical Sciences: Faculty Publications

Enhancement Of Efficacy Of Prrsv Vaccines By Altering The Glycosylation Pattern Of Viral Glycoproteins, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Otk18, A Zinc-Finger Protein, Regulates Human Immunodeficiency Virus Type 1 Long Terminal Repeat Through Two Distinct Regulatory Regions, Masahide Horiba, Lindsey B. Martinez, James L. Buescher, Sinji Sato, Jenae Limoges, Yunquan Jiang, Clinton J. Jones, Tsuneya Ikezu

School of Veterinary and Biomedical Sciences: Faculty Publications

Isotype-Specific Antibody Responses Against Escherichia Coli O157:H7 Locus Of Enterocyte Effacement Proteins In Adult Beef Cattle Following Experimental Infection, G. Bretschneider, E. M. Berberov, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

Low Molecular Weight Protein Tyrosine Phosphatase (Lmw-Ptp) And Its Possible Physiological Functions Of Redox Signaling In The Eye Lens, Kuiyi Xing, Ashraf Raza, Stefan Lofgren, M. Rohan Fernando, Ye-Shih Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

The Infected Cell Protein 0 Encoded By Bovine Herpesvirus 1 (Bicp0) Induces Degradation Of Interferon Response Factor 3 And, Consequently, Inhibits Beta Interferon Promoter Activity, Kazima Saira, You Zhou, Clinton J. Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Localization Of Period 1 Mrna In The Ruminant Oocyte And Investigations Of Its Role In Ovarian Function, R. A. Cushman, M. F. Allan, S. A. Jones, Gary P. Rupp, S. E. Echternkamp

School of Veterinary and Biomedical Sciences: Faculty Publications

School of Veterinary and Biomedical Sciences: Faculty Publications