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Lai X, Wu A, Yu B, Yan H, Luo J, Zheng P, Yu J, Chen D. Retinoic acid alleviates rotavirus-induced intestinal damage by regulating redox homeostasis and autophagic flux in piglets. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2024; 16:409-421. [PMID: 38371474 PMCID: PMC10874719 DOI: 10.1016/j.aninu.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 12/11/2023] [Accepted: 12/28/2023] [Indexed: 02/20/2024]
Abstract
Rotaviruses (RV) are a major cause of severe gastroenteritis, particularly in neonatal piglets. Despite the availability of effective vaccines, the development of antiviral therapies for RV remains an ongoing challenge. Retinoic acid (RA), a metabolite of vitamin A, has been shown to have anti-oxidative and antiviral properties. However, the mechanism by which RA exerts its intestinal-protective and antiviral effects on RV infection is not fully understood. The study investigates the effects of RA supplementation in Duroc × Landrace × Yorkshire (DLY) piglets challenged with RV. Thirty-six DLY piglets were assigned into six treatments, including a control group, RA treatment group with two concentration gradients (5 and 15 mg/d), RV treatment group, and RV treatment group with the addition of different concentration gradients of RA (5 and 15 mg/d). Our study revealed that RV infection led to extensive intestinal architecture damage, which was mitigated by RA treatment at lower concentrations by increasing the villus height and villus height/crypt depth ratio (P < 0.05), enhancing intestinal stem cell signaling and promoting intestinal barrier functions. In addition, 15 mg/d RA supplementation significantly increased NRF2 and HO-1 protein expression (P < 0.05) and GSH content (P < 0.05), indicating that RA supplementation can enhance anti-oxidative signaling and redox homeostasis after RV challenge. Additionally, the research demonstrated that RA exerts a dual impact on the regulation of autophagy, both stimulating the initiation of autophagy and hindering the flow of autophagic flux. Through the modulation of autophagic flux, RA influence the progression of RV infection. These findings provide new insights into the regulation of redox hemostasis and autophagy by RA and its potential therapeutic application in RV infection.
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Affiliation(s)
- Xin Lai
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
| | - Aimin Wu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Hui Yan
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Junqiu Luo
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- Key Laboratory for Animal Disease-resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu, China
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Swevers L, Kontogiannatos D, Kolliopoulou A, Ren F, Feng M, Sun J. Mechanisms of Cell Entry by dsRNA Viruses: Insights for Efficient Delivery of dsRNA and Tools for Improved RNAi-Based Pest Control. Front Physiol 2021; 12:749387. [PMID: 34858204 PMCID: PMC8632066 DOI: 10.3389/fphys.2021.749387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/11/2021] [Indexed: 12/18/2022] Open
Abstract
While RNAi is often heralded as a promising new strategy for insect pest control, a major obstacle that still remains is the efficient delivery of dsRNA molecules within the cells of the targeted insects. However, it seems overlooked that dsRNA viruses already have developed efficient strategies for transport of dsRNA molecules across tissue barriers and cellular membranes. Besides protecting their dsRNA genomes in a protective shell, dsRNA viruses also display outer capsid layers that incorporate sophisticated mechanisms to disrupt the plasma membrane layer and to translocate core particles (with linear dsRNA genome fragments) within the cytoplasm. Because of the perceived efficiency of the translocation mechanism, it is well worth analyzing in detail the molecular processes that are used to achieve this feat. In this review, the mechanism of cell entry by dsRNA viruses belonging to the Reoviridae family is discussed in detail. Because of the large amount of progress in mammalian versus insect models, the mechanism of infections of reoviruses in mammals (orthoreoviruses, rotaviruses, orbiviruses) will be treated as a point of reference against which infections of reoviruses in insects (orbiviruses in midges, plant viruses in hemipterans, insect-specific cypoviruses in lepidopterans) will be compared. The goal of this discussion is to uncover the basic principles by which dsRNA viruses cross tissue barriers and translocate their cargo to the cellular cytoplasm; such knowledge subsequently can be incorporated into the design of dsRNA virus-based viral-like particles for optimal delivery of RNAi triggers in targeted insect pests.
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Affiliation(s)
- Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Dimitrios Kontogiannatos
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research “Demokritos”, Athens, Greece
| | - Feifei Ren
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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Abstract
Group A rotaviruses (RVAs) are the major cause of severe acute gastroenteritis (AGE) in children under 5 years of age, annually resulting in nearly 130,000 deaths worldwide. Social conditions in developing countries that contribute to decreased oral rehydration and vaccine efficacy and the lack of approved antiviral drugs position RVA as a global health concern. In this minireview, we present an update in the field of antiviral compounds, mainly in relation to the latest findings in RVA virion structure and the viral replication cycle. In turn, we attempt to provide a perspective on the possible treatments for RVA-associated AGE, with special focus on novel approaches, such as those representing broad-spectrum therapeutic options. In this context, the modulation of host factors, lipid droplets, and the viral polymerase, which is highly conserved among AGE-causing viruses, are analyzed as possible drug targets.
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Reovirus σ1 Conformational Flexibility Modulates the Efficiency of Host Cell Attachment. J Virol 2020; 94:JVI.01163-20. [PMID: 32938765 DOI: 10.1128/jvi.01163-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/09/2020] [Indexed: 02/07/2023] Open
Abstract
Reovirus attachment protein σ1 is a trimeric molecule containing tail, body, and head domains. During infection, σ1 engages sialylated glycans and junctional adhesion molecule-A (JAM-A), triggering uptake into the endocytic compartment, where virions are proteolytically converted to infectious subvirion particles (ISVPs). Further disassembly allows σ1 release and escape of transcriptionally active reovirus cores into the cytosol. Electron microscopy has revealed a distinct conformational change in σ1 from a compact form on virions to an extended form on ISVPs. To determine the importance of σ1 conformational mobility, we used reverse genetics to introduce cysteine mutations that can cross-link σ1 by establishing disulfide bonds between structurally adjacent sites in the tail, body, and head domains. We detected phenotypic differences among the engineered viruses. A mutant with a cysteine pair in the head domain replicates with enhanced kinetics, forms large plaques, and displays increased avidity for JAM-A relative to the parental virus, mimicking properties of ISVPs. However, unlike ISVPs, particles containing cysteine mutations that cross-link the head domain uncoat and transcribe viral positive-sense RNA with kinetics similar to the parental virus and are sensitive to ammonium chloride, which blocks virion-to-ISVP conversion. Together, these data suggest that σ1 conformational flexibility modulates the efficiency of reovirus host cell attachment.IMPORTANCE Nonenveloped virus entry is an incompletely understood process. For reovirus, the functional significance of conformational rearrangements in the attachment protein, σ1, that occur during entry and particle uncoating are unknown. We engineered and characterized reoviruses containing cysteine mutations that cross-link σ1 monomers in nonreducing conditions. We found that the introduction of a cysteine pair in the receptor-binding domain of σ1 yielded a virus that replicates with faster kinetics than the parental virus and forms larger plaques. Using functional assays, we found that cross-linking the σ1 receptor-binding domain modulates reovirus attachment but not uncoating or transcription. These data suggest that σ1 conformational rearrangements mediate the efficiency of reovirus host cell binding.
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Fuzawa M, Bai H, Shisler JL, Nguyen TH. The Basis of Peracetic Acid Inactivation Mechanisms for Rotavirus and Tulane Virus under Conditions Relevant for Vegetable Sanitation. Appl Environ Microbiol 2020; 86:e01095-20. [PMID: 32709728 PMCID: PMC7499037 DOI: 10.1128/aem.01095-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 07/21/2020] [Indexed: 01/11/2023] Open
Abstract
We determined the disinfection efficacy and inactivation mechanisms of peracetic acid (PAA)-based sanitizer using pH values relevant for vegetable sanitation against rotavirus (RV) and Tulane virus (TV; a human norovirus surrogate). TV was significantly more resistant to PAA disinfection than RV: for a 2-log10 reduction of virus titer, RV required 1 mg/liter PAA for 3.5 min of exposure, while TV required 10 mg/liter PAA for 30 min. The higher resistance of TV can be explained, in part, by significantly more aggregation of TV in PAA solutions. The PAA mechanisms of virus inactivation were explored by quantifying (i) viral genome integrity and replication using reverse transcription-quantitative PCR (RT-qPCR) and (ii) virus-host receptor interactions using a cell-free binding assay with porcine gastric mucin conjugated with magnetic beads (PGM-MBs). We observed that PAA induced damage to both RV and TV genomes and also decreased virus-receptor interactions, with the latter suggesting that PAA damages viral proteins important for binding its host cell receptors. Importantly, the levels of genome-versus-protein damage induced by PAA were different for each virus. PAA inactivation correlated with higher levels of RV genome damage than of RV-receptor interactions. For PAA-treated TV, the opposite trends were observed. Thus, PAA inactivates each of these viruses via different molecular mechanisms. The findings presented here potentially contribute to the design of a robust sanitation strategy for RV and TV using PAA to prevent foodborne disease.IMPORTANCE In this study, we examined the inactivation mechanisms of peracetic acid (PAA), a sanitizer commonly used for postharvest vegetable washing, for two enteric viruses: Tulane virus (TV) as a human norovirus surrogate and rotavirus (RV). PAA disinfection mechanisms for RV were mainly due to genome damage. In contrast, PAA disinfection in TV was due to damage of the proteins important for binding to its host receptor. We also observed that PAA triggered aggregation of TV to a much greater extent than RV. These studies demonstrate that different viruses are inactivated via different PAA mechanisms. This information is important for designing an optimal sanitation practice for postharvest vegetable washing to minimize foodborne viral diseases.
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Affiliation(s)
- Miyu Fuzawa
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Hezi Bai
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Joanna L Shisler
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Screening for Components/Compounds with Anti-Rotavirus Activity: Detection of Interaction Between Viral Spike Proteins and Glycans. Methods Mol Biol 2020. [PMID: 32306358 DOI: 10.1007/978-1-0716-0430-4_50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Rotaviruses are the major etiologic agents of acute gastroenteritis. Viral attachment to the cell surface is crucial to initiate infection. The VP8∗ domain, the trypsinized cleavage fragment of the outermost spike protein VP4 of rotavirus, has a galectin-like structure required for binding to the cell surface. We used the evanescent-field fluorescence-assisted assay to understand the complex mechanism underlying the virus-glycan/glycoprotein interaction. Besides, we have described virus infection assays, neutralization assay, and pretreatment assay, using cell culture. These approaches using rotavirus particles will provide novel information that has been difficult to obtain from glycan microarray using recombinant VP8∗.
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Liu D, Geng H, Zhang Z, Xing Y, Yang D, Liu Z, Wang D. An Effective Platform for Exploring Rotavirus Receptors by Bacterial Surface Display System. Virol Sin 2019; 35:103-109. [PMID: 31777010 PMCID: PMC7035415 DOI: 10.1007/s12250-019-00174-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022] Open
Abstract
Rotavirus (RV) is a major foodborne pathogen. For RV prevention and control, it is a key to uncover the interaction mechanism between virus and its receptors. However, it is hard to specially purify the viral receptors, including histo-blood group antigens (HBGAs). Previously, the protruding domain protein (P protein) of human norovirus (genotype II.4) was displayed on the surface of Escherichia coli, and it specifically recognized and captured the viral ligands. In order to further verify the feasibility of the system, P protein was replaced by VP8* of RV (G9P[8]) in this study. In the system, VP8* could be correctly released by thrombin treatment with antigenicity retaining, which was confirmed by Western blot and Enzyme-Linked Immunosorbent Assays. Type A HBGAs from porcine gastric mucin (PGM) were recognized and captured by this system. From saliva mixture, the captured viral receptor bound with displayed VP8* was confirmed positive with monoclonal antibody against type A HBGAs. It indicated that the target ligands could be easily separated from the complex matrix. These results demonstrate that the bacterial surface display system will be an effective platform to explore viral receptors/ligands from cell lines or food matrix.
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Affiliation(s)
- Danlei Liu
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.,State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Haoran Geng
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zilei Zhang
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.,State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, 510070, China
| | - Yifan Xing
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Danlu Yang
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhicheng Liu
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Dapeng Wang
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China. .,Shanghai Food Safety and Engineering Technology Research Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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Rodríguez JM, Luque D. Structural Insights into Rotavirus Entry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1215:45-68. [DOI: 10.1007/978-3-030-14741-9_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Rotavirus Genomic RNA Complex Forms via Specific RNA-RNA Interactions: Disruption of RNA Complex Inhibits Virus Infectivity. Viruses 2017; 9:v9070167. [PMID: 28661470 PMCID: PMC5537659 DOI: 10.3390/v9070167] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 01/18/2023] Open
Abstract
Rotavirus (RV), a member of the Reoviridae family, causes infection in children and infants, with high morbidity and mortality. To be viable, the virus particle must package a set of eleven RNA segments. In order to understand the packaging mechanism, here, we co-synthesized sets of RNA segments in vitro in different combinations and detected by two alternate methods: the electrophoretic mobility shift assay (EMSA) and the RNA-bead pull-down assay. We showed that viral positive-sense RNA segments interact with each other in a specific manner, forming RNA complexes, and that the RNA–RNA interactions followed a sequential order initiated by small RV segments. Further, we demonstrated that RNA complexes were perturbed by targeted specific antisense oligoribonucleotides (ORNs) complementary to short RNA sequences, indicating that the RNA–RNA interactions between different segments were sequence-specific. The same inhibitory ORNs also had the capability to inhibit virus replication. The combined in vitro and in vivo data inferred that RNA–RNA interactions and specific complex formation are essential for sorting different segments, possibly prior to, or during, genome packaging. As genome assembly is a universal requirement in the Reoviridae family, this work offers an approach towards a further understanding of the sorting and packaging mechanisms of RV and related dsRNA (double-stranded RNA) viruses.
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Beards G. Rotavirus. WIKIJOURNAL OF MEDICINE 2017. [DOI: 10.15347/wjm/2017.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Fuzawa M, Ku KM, Palma-Salgado SP, Nagasaka K, Feng H, Juvik JA, Sano D, Shisler JL, Nguyen TH. Effect of Leaf Surface Chemical Properties on Efficacy of Sanitizer for Rotavirus Inactivation. Appl Environ Microbiol 2016; 82:6214-6222. [PMID: 27520815 PMCID: PMC5068170 DOI: 10.1128/aem.01778-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/07/2016] [Indexed: 01/23/2023] Open
Abstract
The use of sanitizers is essential for produce safety. However, little is known about how sanitizer efficacy varies with respect to the chemical surface properties of produce. To answer this question, the disinfection efficacies of an oxidant-based sanitizer and a new surfactant-based sanitizer for porcine rotavirus (PRV) strain OSU were examined. PRV was attached to the leaf surfaces of two kale cultivars with high epicuticular wax contents and one cultivar of endive with a low epicuticular wax content and then treated with each sanitizer. The efficacy of the oxidant-based sanitizer correlated with leaf wax content as evidenced by the 1-log10 PRV disinfection on endive surfaces (low wax content) and 3-log10 disinfection of the cultivars with higher wax contents. In contrast, the surfactant-based sanitizer showed similar PRV disinfection efficacies (up to 3 log10) that were independent of leaf wax content. A statistical difference was observed with the disinfection efficacies of the oxidant-based sanitizer for suspended and attached PRV, while the surfactant-based sanitizer showed similar PRV disinfection efficacies. Significant reductions in the entry and replication of PRV were observed after treatment with either disinfectant. Moreover, the oxidant-based-sanitizer-treated PRV showed sialic acid-specific binding to the host cells, whereas the surfactant-based sanitizer increased the nonspecific binding of PRV to the host cells. These findings suggest that the surface properties of fresh produce may affect the efficacy of virus disinfection, implying that food sanitizers should be carefully selected for the different surface characteristics of fresh produce. IMPORTANCE Food sanitizer efficacies are affected by the surface properties of vegetables. This study evaluated the disinfection efficacies of two food sanitizers, an oxidant-based sanitizer and a surfactant-based sanitizer, on porcine rotavirus strain OSU adhering to the leaf epicuticular surfaces of high- and low-wax-content cultivars. The disinfection efficacy of the oxidant-based sanitizer was affected by the surface properties of the vegetables, while the surfactant-based sanitizer was effective for both high- and low-wax leafy vegetable cultivars. This study suggests that the surface properties of vegetables may be an important factor that interacts with disinfection with food sanitizers of rotaviruses adhering to fresh produce.
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Affiliation(s)
- Miyu Fuzawa
- Department of Civil and Environmental Engineering, College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kang-Mo Ku
- Division of Plant and Soil Sciences, Davis College of Agriculture, Natural Resources and Design, West Virginia University, Morgantown, West Virginia, USA
| | - Sindy Paola Palma-Salgado
- Department of Food Science and Human Nutrition, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kenya Nagasaka
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Hao Feng
- Department of Food Science and Human Nutrition, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - John A Juvik
- Department of Crop Science, College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Daisuke Sano
- Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Joanna L Shisler
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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12
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Fusion of the mouse IgG1 Fc domain to the VHH fragment (ARP1) enhances protection in a mouse model of rotavirus. Sci Rep 2016; 6:30171. [PMID: 27439689 PMCID: PMC4954977 DOI: 10.1038/srep30171] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/28/2016] [Indexed: 11/15/2022] Open
Abstract
A variable fragment of a heavy chain antibody (VHH) directed against rotavirus, also referred to as anti-rotavirus protein 1 (ARP1), was shown to confer protection against rotavirus induced diarrhea in infant mouse model of rotavirus induced diarrhea. In this study, we have fused the mouse IgG1 Fc to ARP1 to improve the protective capacity of ARP1 by inducing an Fc-mediated effector function. We have shown that the Fc-ARP1 fusion protein confers significantly increased protection against rotavirus in a neonatal mouse model of rotavirus-induced diarrhea by reducing the prevalence, duration and severity of diarrhea and the viral load in the small intestines, suggesting that the Fc part of immunoglobulins may be engaged in Fc-mediated neutralization of rotavirus. Engineered conventional-like antibodies, by fusion of the Fc part of immunoglobulins to antigen-specific heavy-chain only VHH fragments, might be applied to novel antibody-based therapeutic approaches to enhance elimination of pathogens by activation of distinct effector signaling pathways.
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Smith YE, Vellanki SH, Hopkins AM. Dynamic interplay between adhesion surfaces in carcinomas: Cell-cell and cell-matrix crosstalk. World J Biol Chem 2016; 7:64-77. [PMID: 26981196 PMCID: PMC4768125 DOI: 10.4331/wjbc.v7.i1.64] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/22/2015] [Accepted: 11/04/2015] [Indexed: 02/05/2023] Open
Abstract
Cell-cell and cell-matrix signaling and communication between adhesion sites involve mechanisms which are required for cellular functions during normal development and homeostasis; however these cellular functions and mechanisms are often deregulated in cancer. Aberrant signaling at cell-cell and cell-matrix adhesion sites often involves downstream mediators including Rho GTPases and tyrosine kinases. This review discusses these molecules as putative mediators of cellular crosstalk between cell-cell and cell-matrix adhesion sites, in addition to their attractiveness as therapeutic targets in cancer. Interestingly, inter-junctional crosstalk mechanisms are frequently typified by the way in which bacterial and viral pathogens opportunistically infect or intoxicate mammalian cells. This review therefore also discusses the concept of learning from pathogen-host interaction studies to better understand coordinated communication between cell-cell and cell-matrix adhesion sites, in addition to highlighting the potential therapeutic usefulness of exploiting pathogens or their products to tap into inter-junctional crosstalk. Taken together, we feel that increased knowledge around mechanisms of cell-cell and cell-matrix adhesion site crosstalk and consequently a greater understanding of their therapeutic targeting offers a unique opportunity to contribute to the emerging molecular revolution in cancer biology.
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Guerrero CA, Guerrero RA, Silva E, Acosta O, Barreto E. Experimental Adaptation of Rotaviruses to Tumor Cell Lines. PLoS One 2016; 11:e0147666. [PMID: 26828934 PMCID: PMC4734670 DOI: 10.1371/journal.pone.0147666] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/06/2016] [Indexed: 01/06/2023] Open
Abstract
A number of viruses show a naturally extended tropism for tumor cells whereas other viruses have been genetically modified or adapted to infect tumor cells. Oncolytic viruses have become a promising tool for treating some cancers by inducing cell lysis or immune response to tumor cells. In the present work, rotavirus strains TRF-41 (G5) (porcine), RRV (G3) (simian), UK (G6-P5) (bovine), Ym (G11-P9) (porcine), ECwt (murine), Wa (G1-P8), Wi61 (G9) and M69 (G8) (human), and five wild-type human rotavirus isolates were passaged multiple times in different human tumor cell lines and then combined in five different ways before additional multiple passages in tumor cell lines. Cell death caused by the tumor cell-adapted isolates was characterized using Hoechst, propidium iodide, 7-AAD, Annexin V, TUNEL, and anti-poly-(ADP ribose) polymerase (PARP) and -phospho-histone H2A.X antibodies. Multiple passages of the combined rotaviruses in tumor cell lines led to a successful infection of these cells, suggesting a gain-of-function by the acquisition of greater infectious capacity as compared with that of the parental rotaviruses. The electropherotype profiles suggest that unique tumor cell-adapted isolates were derived from reassortment of parental rotaviruses. Infection produced by such rotavirus isolates induced chromatin modifications compatible with apoptotic cell death.
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Affiliation(s)
- Carlos A. Guerrero
- Department of Physiological Sciences, Faculty of Medicine, Universidad Nacional de Colombia, Bogota, D.C., Colombia
- * E-mail:
| | - Rafael A. Guerrero
- Department of Physiological Sciences, Faculty of Medicine, Universidad Nacional de Colombia, Bogota, D.C., Colombia
| | - Elver Silva
- Department of Physiological Sciences, Faculty of Medicine, Universidad Nacional de Colombia, Bogota, D.C., Colombia
| | - Orlando Acosta
- Department of Physiological Sciences, Faculty of Medicine, Universidad Nacional de Colombia, Bogota, D.C., Colombia
| | - Emiliano Barreto
- Institute of Biotechnology, Universidad Nacional de Colombia, Bogota, D.C., Colombia
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Miyazaki N, Higashiura A, Higashiura T, Akita F, Hibino H, Omura T, Nakagawa A, Iwasaki K. Electron microscopic imaging revealed the flexible filamentous structure of the cell attachment protein P2 of Rice dwarf virus located around the icosahedral 5-fold axes. J Biochem 2015; 159:181-90. [PMID: 26374901 DOI: 10.1093/jb/mvv092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/30/2015] [Indexed: 02/02/2023] Open
Abstract
The minor outer capsid protein P2 of Rice dwarf virus (RDV), a member of the genus Phytoreovirus in the family Reoviridae, is essential for viral cell entry. Here, we clarified the structure of P2 and the interactions to host insect cells. Negative stain electron microscopy (EM) showed that P2 proteins are monomeric and flexible L-shaped filamentous structures of ∼20 nm in length. Cryo-EM structure revealed the spatial arrangement of P2 in the capsid, which was prescribed by the characteristic virion structure. The P2 proteins were visualized as partial rod-shaped structures of ∼10 nm in length in the cryo-EM map and accommodated in crevasses on the viral surface around icosahedral 5-fold axes with hydrophobic interactions. The remaining disordered region of P2 assumed to be extended to the radial direction towards exterior. Electron tomography clearly showed that RDV particles were away from the cellular membrane at a uniform distance and several spike-like densities, probably corresponding to P2, connecting a viral particle to the host cellular membrane during cell entry. By combining the in vitro and in vivo structural information, we could gain new insights into the detailed mechanism of the cell entry of RDV.
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Affiliation(s)
- Naoyuki Miyazaki
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan; Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi, Japan;
| | | | - Tomoko Higashiura
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Fusamichi Akita
- Laboratory of Virology, National Agricultural Research Center, Tsukuba, Ibaraki, Japan; and Photosynthesis Research Center, Graduate School of Natural Science and Technology, Okayama University, Okayama, Okayama, Japan
| | - Hiroyuki Hibino
- Laboratory of Virology, National Agricultural Research Center, Tsukuba, Ibaraki, Japan; and
| | - Toshihiro Omura
- Laboratory of Virology, National Agricultural Research Center, Tsukuba, Ibaraki, Japan; and
| | - Atsushi Nakagawa
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kenji Iwasaki
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan;
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16
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Tsuruta Y, Shibutani ST, Watanabe R, Iwata H. The requirement of environmental acidification for Ibaraki virus infection to host cells. J Vet Med Sci 2015; 78:153-6. [PMID: 26321298 PMCID: PMC4751137 DOI: 10.1292/jvms.15-0222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The effect of environmental acidification on Ibaraki virus (IBAV) infection was tested
using endosomal inhibitory chemicals and low pH treatment. Treatment of target cells with
endosomal inhibitors significantly decreased the progeny virus production. IBAV outer
capsid proteins, VP5 and VP2, were removed from virion when purified IBAV was exposed to
low pH environment. Further experiment showed that the exposure to low pH buffer
facilitated IBAV infection when the cellular endosomal pathway was impaired by bafilomycin
A1. Results obtained in this study suggest that acidic environment is essential to
initiate IBAV infection.
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Affiliation(s)
- Yuya Tsuruta
- Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-0841, Japan
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17
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Venkataram Prasad BV, Shanker S, Hu L, Choi JM, Crawford SE, Ramani S, Czako R, Atmar RL, Estes MK. Structural basis of glycan interaction in gastroenteric viral pathogens. Curr Opin Virol 2014; 7:119-27. [PMID: 25073118 PMCID: PMC4251800 DOI: 10.1016/j.coviro.2014.05.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 05/28/2014] [Indexed: 01/12/2023]
Abstract
A critical event in the life cycle of a virus is its initial attachment to host cells. This involves recognition by the viruses of specific receptors on the cell surface, including glycans. Viruses typically exhibit strain-dependent variations in recognizing specific glycan receptors, a feature that contributes significantly to cell tropism, host specificity, host adaptation and interspecies transmission. Examples include influenza viruses, noroviruses, rotaviruses, and parvoviruses. Both rotaviruses and noroviruses are well known gastroenteric pathogens that are of significant global health concern. While rotaviruses, in the family Reoviridae, are the major causative agents of life-threatening diarrhea in children, noroviruses, which belong to the Caliciviridae family, cause epidemic and sporadic cases of acute gastroenteritis across all age groups. Both exhibit enormous genotypic and serotypic diversity. Consistent with this diversity each exhibits strain-dependent variations in the types of glycans they recognize for cell attachment. This chapter reviews the current status of the structural biology of such strain-dependent glycan specificities in these two families of viruses.
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Affiliation(s)
- B V Venkataram Prasad
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States; Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States.
| | - Sreejesh Shanker
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Liya Hu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Jae-Mun Choi
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Sue E Crawford
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Sasirekha Ramani
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Rita Czako
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Robert L Atmar
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States
| | - Mary K Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, United States
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18
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Teimoori A, Soleimanjahi H, Makvandi M. Characterization and Transferring of Human Rotavirus Double-Layered Particles in MA104 Cells. Jundishapur J Microbiol 2014; 7:e10375. [PMID: 25371799 PMCID: PMC4217670 DOI: 10.5812/jjm.10375] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 04/25/2013] [Accepted: 06/01/2013] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Rotavirus (RV) is a major cause of gastroenteritis in infants and children and is one of the most severe public health problems. Rotaviruses outer layer contains two proteins including VP4 and VP7. These proteins are necessary for host-cell binding and penetration. TLP (triple layer virus particle) of RV is a complete infectious virion that binds to the target cells and internalized at the cytoplasm. The DLP (double layer virus particle) is a non-infectious particle that is formed through exclusion of the outer layer proteins including VP4 and VP7. These DLPs are the transcriptionally active forms of rotavirus. OBJECTIVES The aim of this study was to transfer DLP of RV into cytoplasm of MA104 cells by Lipofectamine and to analyze their replication. MATERIALS AND METHODS Initially, rotavirus was purified by CsCl discontinuous gradient and DLP was separated from TLP based on density differences. For confirmation, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the proteins were conducted Then the purified DLP of RV was transferred into MA104 cells using Lipofectamine. RESULTS We attempt to avoid the attachment and entry of the rotavirus by using Lipofectamine to mediate the delivery of viral particles directly into the cytoplasm. DLP was endocytosed into the cytoplasm following treatment by Lipofectamine and then replicated in cytoplasm. CONCLUSIONS Therefore the non-infectious DLPs were became infectious if introduced into the cytoplasm of permissive and cancerous cells, without passing attachment and entry process.
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Affiliation(s)
- Ali Teimoori
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran
| | - Hoorieh Soleimanjahi
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran
- Corresponding author: Hoorieh Soleimanjahi, Department of Virology, Faculty of Medical Science, Tarbiat Modares University, Tehran, IR Iran. Tel/Fax: +98-2182883561, E-mail:
| | - Manoochehr Makvandi
- Department of Virology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
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Proteolytic activation of the porcine epidemic diarrhea coronavirus spike fusion protein by trypsin in cell culture. J Virol 2014; 88:7952-61. [PMID: 24807723 DOI: 10.1128/jvi.00297-14] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Isolation of porcine epidemic diarrhea coronavirus (PEDV) from clinical material in cell culture requires supplementation of trypsin. This may relate to the confinement of PEDV natural infection to the protease-rich small intestine of pigs. Our study focused on the role of protease activity on infection by investigating the spike protein of a PEDV isolate (wtPEDV) using a reverse genetics system based on the trypsin-independent cell culture-adapted strain DR13 (caPEDV). We demonstrate that trypsin acts on the wtPEDV spike protein after receptor binding. We mapped the genetic determinant for trypsin-dependent cell entry to the N-terminal region of the fusion subunit of this class I fusion protein, revealing a conserved arginine just upstream of the putative fusion peptide as the potential cleavage site. Whereas coronaviruses are typically processed by endogenous proteases of the producer or target cell, PEDV S protein activation strictly required supplementation of a protease, enabling us to study mechanistic details of proteolytic processing. Importance: Recurring PEDV epidemics constitute a serious animal health threat and an economic burden, particularly in Asia but, as of recently, also on the North-American subcontinent. Understanding the biology of PEDV is critical for combatting the infection. Here, we provide new insight into the protease-dependent cell entry of PEDV.
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Abstract
Viral particles consist essentially of a proteinaceous capsid protecting a genome and involved also in many functions during the virus life cycle. In simple viruses, the capsid consists of a number of copies of the same, or a few different proteins organized into a symmetric oligomer. Structurally complex viruses present a larger variety of components in their capsids than simple viruses. They may contain accessory proteins with specific architectural or functional roles; or incorporate non-proteic elements such as lipids. They present a range of geometrical variability, from slight deviations from the icosahedral symmetry to complete asymmetry or even pleomorphism. Putting together the many different elements in the virion requires an extra effort to achieve correct assembly, and thus complex viruses require sophisticated mechanisms to regulate morphogenesis. This chapter provides a general view of the structure and assembly of complex viruses.
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Affiliation(s)
- Mauricio G. Mateu
- "Severo Ochoa" (CSIC_UAM), And Dept. of Molecular Biology, Centro de Biología Molecular, Cantoblanco, Madrid, 28049 Madrid Spain
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21
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Santana AY, Guerrero CA, Acosta O. Implication of Hsc70, PDI and integrin αvβ3 involvement during entry of the murine rotavirus ECwt into small-intestinal villi of suckling mice. Arch Virol 2013; 158:1323-36. [PMID: 23404461 DOI: 10.1007/s00705-013-1626-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 12/23/2012] [Indexed: 11/25/2022]
Abstract
In the present study, a homologous rotavirus, ECwt, infecting small intestinal villi isolated from ICR and BALB/c mice were used as a model for identifying cell-surface molecules involved in rotavirus entry. Small-intestinal villi were treated with anti-Hsc70, anti-PDI, anti-integrin β3 or anti-ERp57 antibodies or their corresponding F(ab')2 fragments before inoculation with rotavirus ECwt, RRV or Wa. Pretreatment of villi decreased virus infectivity by about 50-100 % depending of the rotavirus strain, antibody structure and detection assay used. Similar results were obtained by treating viral inocula with purified proteins Hsc70, PDI or integrin β3 before inoculation of untreated villi. Rotavirus infection of villi proved to be sensitive to membrane-impermeant thiol/disulfide inhibitors such as DTNB and bacitracin, suggesting the involvement of a redox reaction in infection. The present results suggest that PDI, Hsc70 and integrin β3 are used by both homologous and heterologous rotaviruses during infection of isolated mouse villi.
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Affiliation(s)
- Ana Y Santana
- Instituto de Biotecnología, Universidad Nacional de Colombia, Bogotá, Colombia
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22
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Abstract
PURPOSE OF REVIEW New knowledge on rotavirus infection in children and well established mouse models has renewed interest in whether rotavirus could cause biliary atresia, an idiopathic, obliterative infantile disease of bile ducts that is the primary indication for liver transplant in children. RECENT FINDINGS Studies in the rotavirus mouse model of biliary atresia indicate that infection of biliary epithelium is an inaugural event leading to biliary inflammation and obstruction, which is preceded by systemic spread of rotavirus, which also occurs during human rotavirus enteric infections. Viral factors, including rotavirus gene 4, are important for biliary infection and biliary atresia in mice. Specific host factors related to inflammatory processes (natural killer and T cells, interferon) are also critical, and a paucity of regulatory T cells in neonates may play a key role in pathogenesis in experimental biliary atresia. Rotavirus vaccination has substantially decreased rotavirus diarrheal disease worldwide and might enable demonstration of a cause-effect relationship between rotavirus infection and biliary atresia in humans. SUMMARY Rotavirus can be detected in the serum of mice and children and causes biliary atresia in neonatal mice. Approaches to re-examine whether rotavirus causes biliary atresia in children are discussed based on concepts from the mouse model of biliary atresia and rotavirus vaccination programs.
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23
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Fiege B, Rademacher C, Cartmell J, Kitov PI, Parra F, Peters T. Molecular Details of the Recognition of Blood Group Antigens by a Human Norovirus as Determined by STD NMR Spectroscopy. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201105719] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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24
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Fiege B, Rademacher C, Cartmell J, Kitov PI, Parra F, Peters T. Molecular details of the recognition of blood group antigens by a human norovirus as determined by STD NMR spectroscopy. Angew Chem Int Ed Engl 2011; 51:928-32. [PMID: 22170811 DOI: 10.1002/anie.201105719] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Indexed: 01/26/2023]
Affiliation(s)
- Brigitte Fiege
- Center of Structural and Cell Biology in Medicine, Institute of Chemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
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25
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McDonald SM, Patton JT. Assortment and packaging of the segmented rotavirus genome. Trends Microbiol 2011; 19:136-44. [PMID: 21195621 PMCID: PMC3072067 DOI: 10.1016/j.tim.2010.12.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 11/19/2010] [Accepted: 12/01/2010] [Indexed: 12/13/2022]
Abstract
The rotavirus (RV) genome comprises 11 segments of double-stranded RNA (dsRNA) and is contained within a non-enveloped, icosahedral particle. During assembly, a highly coordinated selective packaging mechanism ensures that progeny RV virions contain one of each genome segment. Cis-acting signals thought to mediate assortment and packaging are associated with putative panhandle structures formed by base-pairing of the ends of RV plus-strand RNAs (+RNAs). Viral polymerases within assembling core particles convert the 11 distinct +RNAs to dsRNA genome segments. It remains unclear whether RV +RNAs are assorted before or during encapsidation, and the functions of viral proteins during these processes are not resolved. However, as reviewed here, recent insights gained from the study of RV and two other segmented RNA viruses, influenza A virus and bacteriophage Φ6, reveal potential mechanisms of RV assortment and packaging.
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Affiliation(s)
- Sarah M McDonald
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-8026, USA
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26
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Rhesus rotavirus entry into a polarized epithelium is endocytosis dependent and involves sequential VP4 conformational changes. J Virol 2010; 85:2492-503. [PMID: 21191022 DOI: 10.1128/jvi.02082-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Rotavirus (RV) cell entry is an incompletely understood process, involving VP4 and VP7, the viral proteins composing the outermost layer of the nonenveloped RV triple-layered icosahedral particle (TLP), encasing VP6. VP4 can exist in three conformational states: soluble, cleaved spike, and folded back. In order to better understand the events leading to RV entry, we established a detection system to image input virus by monitoring the rhesus RV (RRV) antigens VP4, VP6, and VP7 at very early times postinfection. We provide evidence that decapsidation occurs directly after cell membrane penetration. We also demonstrate that several VP4 and VP7 conformational changes take place during entry. In particular, we detected, for the first time, the generation of folded-back VP5 in the context of the initiation of infection. Folded-back VP5 appears to be limited to the entry step. We furthermore demonstrate that RRV enters the cell cytoplasm through an endocytosis pathway. The endocytosis hypothesis is supported by the colocalization of RRV antigens with the early endosome markers Rab4 and Rab5. Finally, we provide evidence that the entry process is likely dependent on the endocytic Ca(2+) concentration, as bafilomycin A1 treatment as well as an augmentation of the extracellular calcium reservoir using CaEGTA, which both lead to an elevated intraendosomal calcium concentration, resulted in the accumulation of intact virions in the actin network. Together, these findings suggest that internalization, decapsidation, and cell membrane penetration involve endocytosis, calcium-dependent uncoating, and VP4 conformational changes, including a fold-back.
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27
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RGD motif of lipoprotein T, involved in adhesion of Mycoplasma conjunctivae to lamb synovial tissue cells. J Bacteriol 2010; 192:3773-9. [PMID: 20494988 DOI: 10.1128/jb.00253-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipoprotein T (LppT), a membrane-located 105-kDa lipoprotein of Mycoplasma conjunctivae, the etiological agent of infectious keratoconjunctivitis (IKC) of domestic sheep and wild Caprinae, was characterized. LppT was shown to promote cell attachment to LSM 192 primary lamb joint synovial cells. Adhesion of M. conjunctivae to LSM 192 cells is inhibited by antibodies directed against LppT. The RGD (Arg-Gly-Asp) motif of LppT was found to be a specific site for binding of M. conjunctivae to these eukaryotic host cells. Recombinant LppT fixed to polymethylmethacrylate slides binds LSM 192 cells, whereas LppT lacking the RGD site is deprived of binding capacity to LSM 192, and LppT containing RGE rather than RGD shows reduced binding. Synthetic nonapeptides derived from LppT containing RGD competitively inhibit binding of LSM 192 cells to LppT-coated slides, whereas nonapeptides containing RAD rather than RGD do not inhibit. RGD-containing, LppT-derived nonapeptides are able to directly inhibit binding of M. conjunctivae to LSM 192 cells by competitive inhibition, whereas the analogous nonapeptide containing RAD rather than RGD or the fibronectin-derived RGD hexapeptide has no inhibitory effect. These results reveal LppT as the first candidate of a RGD lectin in Mycoplasma species that is assumed to bind to beta integrins.
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