51 results on '"Asfor AS"'
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2. Instrumentos processuais de controle dos regulamentos à luz dos ordenamentos jurídicos brasileiro e português
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Lucas Asfor Rocha Lima
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General Medicine - Abstract
O tema central deste estudo é a análise dos instrumentos processuais de controle jurisdicional dos regulamentos de uma perspectiva comparada entre os ordenamentos jurídicos brasileiro e português, tema reconhecidamente atrativo e ainda de grande utilização prática. A metodologia aqui empregada consiste em um cotejo analítico entre os dois sistemas jurídicos acerca das ações judiciais com vistas a exercer o devido controle sobre os atos regulatórios, como forma de consolidação do estado democrático de direito.
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- 2022
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3. An Infectious Bursal Disease Virus (IBDV) Reverse Genetics Rescue System and Neutralization Assay in Chicken B Cells
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Vishwanatha R. A. P. Reddy, Salik Nazki, Amin Asfor, and Andrew J. Broadbent
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Medical Laboratory Technology ,General Immunology and Microbiology ,General Neuroscience ,Health Informatics ,General Pharmacology, Toxicology and Pharmaceutics ,General Biochemistry, Genetics and Molecular Biology - Abstract
Infectious bursal disease virus (IBDV) is a major threat to the productivity of the poultry industry due to morbidity, mortality, and immunosuppression that exacerbates secondary infections and reduces the efficacy of vaccination programs. Field strains of IBDV have a preferred tropism for chicken B cells, the majority of which reside in the bursa of Fabricius (BF). IBDV adaptation to adherent cell culture is associated with mutations altering amino acids in the hypervariable region (HVR) of the capsid protein, which affects immunogenicity and virulence. Until recently, this has limited both the application of reverse genetics systems for engineering molecular clones, and the use of in vitro neutralization assays, to cell-culture-adapted strains of IBDV. Here, we describe the rescue of molecular clones of IBDV containing the HVR from diverse field strains, along with a neutralization assay to quantify antibody responses against the rescued viruses, both using chicken B cells. These methods are readily adaptable to any laboratory with molecular biology expertise and negate the need to obtain wild-type strains. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: A chicken B-cell rescue system for IBDV Basic Protocol 2: A chicken B-cell neutralization assay for IBDV.
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- 2023
4. Evaluating the Breadth of Neutralizing Antibody Responses Elicited by Infectious Bursal Disease Virus Genogroup A1 Strains Using a Novel Chicken B-Cell Rescue System and Neutralization Assay
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Vishwanatha R. A. P. Reddy, Salik Nazki, Andrew J. Brodrick, Amin Asfor, Joanna Urbaniec, Yasmin Morris, and Andrew J. Broadbent
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Epitopes ,Genotype ,Virology ,Insect Science ,Immunology ,Australia ,Animals ,Birnaviridae Infections ,Antibodies, Neutralizing ,Chickens ,Infectious bursal disease virus ,Microbiology ,Poultry Diseases - Abstract
Eight infectious bursal disease virus (IBDV) genogroups have been identified based on the sequence of the capsid hypervariable region (HVR) (A1 to A8). Given reported vaccine failures, there is a need to evaluate the ability of vaccines to neutralize the different genogroups. To address this, we used a reverse genetics system and the chicken B-cell line DT40 to rescue a panel of chimeric IBDVs and perform neutralization assays. Chimeric viruses had the backbone of a lab-adapted strain (PBG98) and the HVRs from diverse field strains as follows: classical F52-70 (A1), U.S. variant Del-E (A2), Chinese variant SHG19 (A2), very virulent UK661 (A3), M04/09 distinct (A4), Italian ITA-04 (A6), and Australian variant Vic-01/94 (A8). Rescued viruses showed no substitutions at amino acid positions 253, 284, or 330, previously found to be associated with cell-culture adaptation. Sera from chickens inoculated with wild-type (wt) (F52-70) or vaccine (228E) A1 strains had the highest mean virus neutralization (VN) titers against the A1 virus (log
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- 2022
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5. Evaluating the breadth of neutralizing antibody responses elicited by infectious bursal disease virus (IBDV) genogroup A1 strains using a novel chicken B-cell rescue system and neutralization assay
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Vishwanatha R. A. P. Reddy, Salik Nazki, Andrew J. Brodrick, Amin Asfor, Joanna Urbaniec, Yasmin Morris, and Andrew J. Broadbent
- Abstract
Eight infectious bursal disease virus (IBDV) genogroups have been identified based on the sequence of the capsid hypervariable region (HVR) (A1-8), yet many vaccines are based on A1 strains. Given reported vaccine failures, there is a need to evaluate the ability of vaccines to neutralize the different genogroups. To address this, we used a reverse genetics system and the chicken B-cell line DT40 to rescue a panel of chimeric IBDVs and perform neutralization assays. Chimeric viruses had the backbone of a lab-adapted strain (PBG98) and the HVRs from diverse field strains: classical F52-70 (A1), US-variant Del-E (A2), Chinese-variant SHG19 (A2), very-virulent UK661 (A3), M04/09 distinct (A4), Italian ITA-04 (A6), and Australian-variant Vic-01/94 (A8). Rescued viruses showed no substitutions at amino-acid positions 253, 284, or 330, previously associated with cell-culture adaptation. Sera from chickens inoculated with wt (F52-70) or vaccine (228E) A1 strains had the highest mean virus neutralization (VN) titers against the A1 virus (log2 15.41 and 12.66), and the lowest against A2 viruses (log2 7.41-7.91, p=0.0001-0.0274), consistent with A1 viruses being most antigenically distant from A2 strains, which correlated with the extent of differences in the predicted HVR structure. VN titers against the other genogroups ranged from log2 9.32-13.32, and A1 strains were likely more closely antigenically related to genogroups A3 and A4 than A6 and A8. Our data are consistent with field observations, validating our method, which can used to screen future vaccine candidates for breadth of neutralizing antibodies, and evaluate the antigenic relatedness of different genogroups.ImportanceThere is a need to evaluate the ability of vaccines to neutralize diverse IBDV genogroups, and to better understand the relationship between HVR sequence, structure, and antigenicity. Here, we used a chicken B cell-line to rescue a panel of chimeric IBDVs with the HVR from seven diverse IBDV field strains, and conduct neutralization assays and protein modelling. We evaluated the ability of serum from vaccinated or infected birds to neutralize the different genogroups. Our novel chicken B-cell rescue system and neutralization assay can be used to screen IBDV vaccine candidates, platforms, and regimens for the breadth of neutralizing antibody responses elicited, evaluate the antigenic relatedness of diverse IBDV strains, and when coupled with structural modelling, elucidate immunodominant and conserved epitopes to strategically design novel IBDV vaccines in the future.
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- 2022
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6. Exploring foot-and-mouth disease virus antibody interactions using biolayer interferometry
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Andrew Shaw, Alison Burman, Amin Asfor, Anna Ludi, Emiliana Brocchi, Santina Grazioli, and Donald King
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General Materials Science - Abstract
Foot-and-mouth disease virus (FMDV) vaccines protect animals from infection by inducing antibodies. The level of neutralising antibody induced in response to vaccination (or infection), as measured by a virus neutralisation test, is an important parameter with regards to the level of protection afforded against subsequent challenge. However, in addition to overall titre, antibody avidity also represents a crucial metric when assessing the protective efficacy of antibodies. In this project we investigated the use of biolayer interferometry (BLI) to measure the avidity of FMDV antibodies to FMDV antigens. Antibodies targeting site I of the FMDV particle were detected using a commercially synthesised biotinylated peptide. In contrast, the entire antigenic landscape of the FMDV particle was represented by biotinylated FMDV capsids. The antigens were loaded onto Octet streptavidin biosensors at an optimal concentration prior to dipping into antibodies. The sera from different animals varied in avidity, reflecting the quantitative differences in avidity that exist between individual animals in response to FMDV vaccines. Interestingly, the Kdis values obtained for site I vs the entire capsid were different, supporting the importance of other sites beyond site I. Similarly, monoclonal antibodies targeting distinct, known antigenic sites on the capsid surface also resulted in different avidities. The BLI methodology reported here offers a useful approach by which to investigate the strength of antibody interactions at specific sites. In conjunction with recombinant technology, BLI will help aid in investigations into the relative importance of the different antigenic sites with regards to inducing a protective response.
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- 2022
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7. Modeling Infectious Bursal Disease Virus (IBDV) Antigenic Drift In Vitro
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Amin S. Asfor, Vishwanatha R. A. P. Reddy, Salik Nazki, Joanna Urbaniec, Andrew J. Brodrick, and Andrew J. Broadbent
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Infectious Diseases ,Virology - Abstract
Infectious bursal disease virus (IBDV) vaccines do not induce sterilizing immunity, and vaccinated birds can become infected with field strains. Vaccine-induced immune selection pressure drives the evolution of antigenic drift variants that accumulate amino acid changes in the hypervariable region (HVR) of the VP2 capsid, which may lead to vaccine failures. However, there is a lack of information regarding how quickly mutations arise, and the relative contribution different residues make to immune escape. To model IBDV antigenic drift in vitro, we serially passaged a classical field strain belonging to genogroup A1 (F52/70) ten times, in triplicate, in the immortalized chicken B cell line, DT40, in the presence of sub-neutralizing concentrations of sera from birds inoculated with IBDV vaccine strain 2512, to generate escape mutants. This assay simulated a situation where classical strains may infect birds that have suboptimal vaccine-induced antibody responses. We then sequenced the HVR of the VP2 capsid at passage (P) 5 and 10 and compared the sequences to the parental virus (P0), and to the virus passaged in the presence of negative control chicken serum that lacked IBDV antibodies. Two escape mutants at P10 had the same mutations, D279Y and G281R, and a third had mutations S251I and D279N. Furthermore, at P5, the D279Y mutation was detectable, but the G281R mutation was not, indicating the mutations arose with different kinetics.
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- 2022
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8. Transcriptomic analysis reveals that severity of infectious bursal disease in White Leghorn inbred chicken lines is associated with greater bursal inflammation in vivo and more rapid induction of pro-inflammatory responses in primary bursal cells stimulated ex vivo
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Salik Nazki, Amin S. Asfor, Michael A. Skinner, Katherine L Dulwich, Elle A. Campbell, Broadbent Aj, Efstathios S. Giotis, and Vishwanatha R A P Reddy
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animal structures ,medicine.medical_treatment ,Inflammation ,Biology ,medicine.disease ,Virology ,Virus ,Infectious bursal disease ,Cytokine ,Inbred strain ,In vivo ,medicine ,Flock ,medicine.symptom ,Ex vivo - Abstract
In order to better understand differences in the outcome of infectious bursal disease virus (IBDV) infection, we inoculated a very virulent (vv) strain into White Leghorn chickens of inbred line W that was previously reported to experience over 24% flock mortality, and three inbred lines (15I, C.B4 and 0) that were previously reported to display no mortality. Within each experimental group, some individuals experienced more severe disease than others but line 15I birds experienced milder disease based on average clinical scores, percentage of birds with gross pathology, average bursal lesion scores and average peak bursal virus titre. RNA-Seq analysis revealed that more severe disease in line W was associated with significant up-regulation of pathways involved in inflammation, cytoskeletal regulation by Rho GTPases, nicotinic acetylcholine receptor signaling, and Wnt signaling in the bursa compared to line 15I. Primary bursal cell populations isolated from uninfected line W birds contained a significantly greater percentage of KUL01+ macrophages than cells isolated from line 15I birds (pex vivo with LPS, showed more rapid up-regulation of pro-inflammatory gene expression than those from line 15I birds. We hypothesize that a more rapid induction of pro-inflammatory cytokine responses in bursal cells following IBDV infection leads to more severe disease in line W birds than in line 15I.
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- 2021
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9. Cross-Serotype Reactivity of ELISAs Used to Detect Antibodies to the Structural Proteins of Foot-and-Mouth Disease Virus
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Anna B. Ludi, Alison Morris, Simon Gubbins, Amin Asfor, Madeeha Afzal, Clare F. Browning, Santina Grazioli, Efrem Alessandro Foglia, Ginette Wilsden, Alison Burman, Emiliana Brocchi, David J. Paton, and Donald P. King
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Epitopes ,Infectious Diseases ,Foot-and-Mouth Disease Virus ,Foot-and-Mouth Disease ,Virology ,Animals ,Capsid Proteins ,Cattle ,Enzyme-Linked Immunosorbent Assay ,Antibodies, Viral ,Serogroup ,foot-and-mouth disease virus ,serology ,cross-reactivity ,antibody ,SP-ELISA - Abstract
Antibodies to the foot-and-mouth disease virus (FMDV) capsid induced by infection or vaccination can provide serotype-specific protection and be measured using virus neutralization tests and viral structural-protein (SP-)ELISAs. Separate tests are needed for each serotype, but cross-serotype reactions complicate serotyping. In this study, inter-serotypic responses were quantified for five SP-ELISA formats by testing 294 monovalent mainly bovine sera collected following infection, vaccination, or vaccination and infection with one of five serotypes of FMDV. Over half of the samples, representing all three immunization categories, scored positive for at least one heterologous serotype and some scored positive for all serotypes tested. A comparative approach to identifying the strongest reaction amongst serotypes O, A and Asia 1 improved the accuracy of serotyping to 73–100% depending on the serotype and test system, but this method will be undermined where animals have been infected and/or vaccinated with multiple FMDV serotypes. Preliminary studies with stabilized recombinant capsid antigens of serotypes O and A that do not expose internal epitopes showed reduced cross-reactivity, supporting the hypothesis that capsid integrity can affect the serotype-specificity of the SP-ELISAs. The residual cross-reactivity associated with capsid surface epitopes was consistent with the evidence of cross-serotype virus neutralization.
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- 2022
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10. A COVID-19 vaccine candidate using SpyCatcher multimerization of the SARS-CoV-2 spike protein receptor-binding domain induces potent neutralising antibody responses
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Amin S. Asfor, Saira Hussain, Matthew Tully, Alain Townsend, Jane C. Edwards, Rebecca K. McLean, Rolle Rahikainen, Ryan Waters, Julia A. Tree, Phoebe Stevenson-Leggett, Adrian K. Zagrajek, Tomas Malinauskas, Isabelle Dietrich, John W. McCauley, Kuan-Ying A. Huang, Dagmara Bialy, Clare Browning, Tobias J. Tuthill, Elma Tchilian, Dalan Bailey, Jiandong Huo, Anna B. Ludi, Sylvia Crossley, Nazia Thakur, Philippa Hollinghurst, Carina Conceicao, Alison Burman, Christopher Chiu, Pramila Rijal, Ginette Wilsden, Holly Shelton, M. Pedrera, Valerie Mioulet, Raymond J. Owens, Ashley R. Gray, John A. Hammond, Karen R. Buttigieg, Joseph Newman, Lisa Schimanski, Simon P. Graham, Jack W.P. Hayes, Rodney S. Daniels, Katy Moffat, Ruth Harvey, Bryan Charleston, Miles W. Caroll, Mark Howarth, Sushant Bhat, Mehreen Azhar, Veronica Martini, Anthony H. Keeble, and Tiong Kit Tan
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chemistry.chemical_classification ,biology ,medicine.drug_class ,Immunogenicity ,Mutant ,Monoclonal antibody ,Virology ,Epitope ,Neutralization ,chemistry ,Polyclonal antibodies ,biology.protein ,medicine ,Antibody ,Glycoprotein - Abstract
There is dire need for an effective and affordable vaccine against SARS-CoV-2 to tackle the ongoing pandemic. In this study, we describe a modular virus-like particle vaccine candidate displaying the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) using SpyTag/SpyCatcher technology (RBD-SpyVLP). Low doses of RBD-SpyVLP in a prime-boost regimen induced a strong neutralising antibody response in mice and pigs that was superior to convalescent human sera. We evaluated antibody quality using ACE2 blocking and neutralisation of cell infection by pseudovirus or wild-type SARS-CoV-2. Using competition assays with a monoclonal antibody panel, we showed that RBD-SpyVLP induced a polyclonal antibody response that recognised all key epitopes on the RBD, reducing the likelihood of selecting neutralisation-escape mutants. The induction of potent and polyclonal antibody responses by RBD-SpyVLP provides strong potential to address clinical and logistic challenges of the COVID-19 pandemic. Moreover, RBD-SpyVLP is highly resilient, thermostable and can be lyophilised without losing immunogenicity, to facilitate global distribution and reduce cold-chain dependence.
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- 2020
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11. Salivary immunoglobulins (A, G, and M) in type 1 diabetes mellitus patients: A PROSPERO-registered systematic review and meta-analysis
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Thyciana Rodrigues Ribeiro, Fábio Wildson Gurgel Costa, Francisco Samuel Rodrigues Carvalho, Paulo Goberlanio de Barros Silva, Sara Maria Silva, Cristiane Sá Roriz Fonteles, and Renata Asfor Rocha Carvalho Martins
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0301 basic medicine ,Immunoglobulin A ,medicine.medical_specialty ,Saliva ,03 medical and health sciences ,0302 clinical medicine ,Diabetes mellitus ,Internal medicine ,medicine ,Humans ,General Dentistry ,Type 1 diabetes ,biology ,business.industry ,030206 dentistry ,Cell Biology ,General Medicine ,medicine.disease ,030104 developmental biology ,Diabetes Mellitus, Type 1 ,Otorhinolaryngology ,Immunoglobulin M ,Strictly standardized mean difference ,Meta-analysis ,Immunoglobulin G ,Immunoglobulin A, Secretory ,biology.protein ,Antibody ,business - Abstract
Objective To assess the difference in the salivary levels of immunoglobulins between patients with type 1 diabetes mellitus (DM1) and healthy controls. Design This systematic review was registered on the PROSPERO (CRD42020159198) database. All references were cross-checked and the risk of bias assessment was conducted using the Newcastle-Ottawa Scale. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to appraise the quality of evidence. The standardized mean difference and Cohen's d as the effect size were used in the meta-analysis. I-square statistics was used to estimate heterogeneity. Analysis was performed using the RevMan® software (p Results Of the total 92 articles, 9 were selected for this study. The meta-analysis included 333 DM1 patients and 325 healthy controls. DM1 patients showed a significant reduction in salivary flow (p = 0.0008; Cohen’s d= −0.19, CI 95 %= −0.33, −0.05), although not significant enough to modify the IgA concentration (p = 0.120; Cohen’s d = 0.58, CI 95 %= −0.15, 1.32). However, DM1 increased IgA concentration by reducing salivary flow (Cohen’s d = 0.84; CI 95 % = 0.36, 1.32), with a strong estimate of effect (p = 0.0006). Regarding IgG, no significant change was noted with DM1 in the patient’s saliva (p = 0.420). Furthermore, there was no significant variation in the salivary IgM levels (p = 0.300). Conclusions The data suggest that the salivary levels of the evaluated immunoglobulins do not seem to be altered in DM1 patients when compared to that in healthy controls. However, the increase in IgA salivary concentration was dependent on total protein estimation.
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- 2020
12. Defining dysmorphic facial features in congenital Zika syndrome
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Francisco Coracy C. Monteiro, Felipe Franco Marçal, Thyciana Rodrigues Ribeiro, Islane Verçosa, Cristiane Sá Roriz Fonteles, Renata Asfor Rocha Carvalho Martins, Erlane Marques Ribeiro, André Luiz Santos Pessoa, André Jalles Monteiro, Cauby Maia Chaves Junior, Luciano Pamplona de Góes Cavalcanti, Grisielle de Sá Cavalcante, Thayse Elaine Costa Figueiredo Lopes, Ana Lalessa Pereira de Oliveira, Fábio Wildson Gurgel Costa, Rebeca Bastos Vasconcelos, and Bianca Palhano Toscano
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0301 basic medicine ,Male ,Craniofacial abnormality ,Physical examination ,030105 genetics & heredity ,Nasal root ,03 medical and health sciences ,Intercanthal distance ,Pregnancy ,Genetics ,medicine ,Humans ,Dysmorphic facial features ,Genetics (clinical) ,medicine.diagnostic_test ,business.industry ,Zika Virus Infection ,Infant ,Anatomy ,Zika Virus ,medicine.disease ,Chin ,Prominent nasal root ,Facial height ,030104 developmental biology ,medicine.anatomical_structure ,Face ,Microcephaly ,Female ,business - Abstract
Congenital Zika syndrome (CZS) constitutes a recently identified malformation caused by Zika virus infection during pregnancy. Limited data is available to date on the facial dysmorphic features of these patients. This study evaluated the facial dysmorphisms of children with CZS, compared with clinically healthy children, using clinical examination and standardized photographic images. Sixty-three children with CZS (9.70 ± 3.2 months-age), and 31 Controls (8.67 ± 6.2 months-age) joined the study. Seven out of 15 indices differed between groups: midfacial height (MFH)/horizontal facial reference (HFR) (p = .0003), interalar distance/HFR (p = .0027), nasal root depth/MFH (p = .0030), posterior nasal length/MFH (p = .0002), vertical position of the ear/MFH (p
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- 2020
13. Evaluation of the immunogenicity of prime-boost vaccination with the replication-deficient viral vectored COVID-19 vaccine candidate ChAdOx1 nCoV-19
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Ginette Wilsden, Holly Shelton, Joseph Newman, Anna B. Ludi, Isabelle Dietrich, Amin S. Asfor, Phoebe Stevenson-Leggett, Teresa Lambe, Miles W. Carroll, Elizabeth R. Allen, Ciaran Gilbride, David Pulido, Sylvia Crossley, Christopher Chiu, John A. Hammond, Sarah C. Gilbert, Alexandra J. Spencer, Nazia Thakur, Philippa Hollinghurst, Jack W.P. Hayes, Katy Moffat, Alison Burman, Valerie Mioulet, Raymond J. Owens, Ryan Waters, Hannah Sharpe, Clare Browning, Tobias J. Tuthill, Marta Ulaszewska, Jiandong Huo, Bryan Charleston, Elma Tchilian, Sushant Bhat, Jane C. Edwards, Dagmara Bialy, Rebecca K. McLean, Daniel B. Wright, Veronica Martini, Carina Conceicao, Sandra Belij-Rammerstorfer, Simon P. Graham, and Dalan Bailey
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0301 basic medicine ,lcsh:Immunologic diseases. Allergy ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Immunology ,Booster immunisation ,Biology ,Simian ,Brief Communication ,lcsh:RC254-282 ,Viral vector ,03 medical and health sciences ,0302 clinical medicine ,Virology ,Pharmacology (medical) ,Pharmacology ,Vaccines ,Immunogenicity ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,biology.organism_classification ,030104 developmental biology ,Infectious Diseases ,Antibody response ,biology.protein ,Prime boost vaccination ,Antibody ,lcsh:RC581-607 ,030215 immunology - Abstract
Clinical development of the COVID-19 vaccine candidate ChAdOx1 nCoV-19, a replication-deficient simian adenoviral vector expressing the full-length SARS-CoV-2 spike (S) protein was initiated in April 2020 following non-human primate studies using a single immunisation. Here, we compared the immunogenicity of one or two doses of ChAdOx1 nCoV-19 in both mice and pigs. Whilst a single dose induced antigen-specific antibody and T cells responses, a booster immunisation enhanced antibody responses, particularly in pigs, with a significant increase in SARS-CoV-2 neutralising titres.
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- 2020
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14. Avidity of Polyclonal Antibodies to Foot-and-Mouth Disease Virus in Bovine Serum Measured Using Bio-Layer Interferometry
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Andrew E. Shaw, Alison Burman, Amin Asfor, Emiliana Brocchi, Santina Grazioli, Clare Browning, Anna Ludi, Tobias J. Tuthill, and Donald P. King
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foot-and-mouth disease virus ,antibodies ,bio-layer interferometry ,avidity ,vaccines ,Interferometry ,Infectious Diseases ,Foot-and-Mouth Disease Virus ,Foot-and-Mouth Disease ,viruses ,Virology ,Animals ,Cattle ,Enzyme-Linked Immunosorbent Assay ,Viral Vaccines ,chemical and pharmacologic phenomena ,Antibodies, Viral - Abstract
Foot-and-mouth disease (FMD) is a disease of cloven-hoofed livestock caused by FMD virus (FMDV). FMD can be controlled through the use of inactivated vaccines, and it is well established that the protection afforded by FMD vaccines correlates strongly with neutralising antibody titres. However, the overall strength of binding, referred to as avidity, is also an important parameter with respect to the ability of antibodies to neutralise virus infection, and there is evidence that avidity can affect the level of protection afforded by FMDV vaccines. Here, as an alternative to modified enzyme-linked immunosorbent assays (avidity ELISAs) incorporating a chaotropic wash step, we used bio-layer interferometry (BLI) to measure the avidity of bovine polyclonal antibodies against FMDV capsids. We conducted preliminary experiments using recombinant FMDV capsids, as well as peptides representing antigenic loops, to demonstrate that the binding of monoclonal antibodies targeting specific antigenic sites could be detected using BLI. Subsequent experiments using polyclonal sera derived from FMD vaccinated cattle provided evidence of a positive correlation between the neutralising titre of the serum and the avidity as measured by BLI. Furthermore, we observed an increase in BLI avidity, as well as in the titre, in vaccinated animals upon challenge with the live virus.
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- 2022
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15. The stronger downregulation ofin vitroandin vivoinnate antiviral responses by a very virulent strain of infectious bursal disease virus (IBDV), compared to a classical strain, is mediated, in part, by the VP4 protein
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Alice Gray, Michael A. Skinner, Katherine L Dulwich, Amin S. Asfor, Andrew J. Broadbent, Efstathios S. Giotis, Biotechnology and Biological Sciences Research Council (BBSRC), and National Centre for the Replacement, Refinement and Reduction of Animals in Research
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0301 basic medicine ,Microbiology (medical) ,IBDV ,viruses ,030106 microbiology ,Immunology ,lcsh:QR1-502 ,Virulence ,Biology ,0601 Biochemistry and Cell Biology ,Microbiology ,lcsh:Microbiology ,Proinflammatory cytokine ,03 medical and health sciences ,In vivo ,Bursa of Fabricius ,030304 developmental biology ,0303 health sciences ,Attenuated vaccine ,Strain (chemistry) ,030306 microbiology ,Virology ,cytokines ,In vitro ,3. Good health ,virulence ,030104 developmental biology ,Infectious Diseases ,Viral replication ,inflammation ,VP4 ,type I IFN ,0605 Microbiology - Abstract
IBDV is economically important to the poultry industry. Very virulent (vv) strains cause higher mortality rates than other strains for reasons that remain poorly understood. In order to provide more information on IBDV disease outcome, groups of chickens (n=18) were inoculated with the vv strain, UK661, or the classical strain, F52/70. Birds infected with UK661 had a lower survival rate (50%) compared to F52/70 (80%). There was no difference in peak viral replication in the bursa of Fabricius (BF), but the expression of chicken IFNβ, MX1 and IL-8 was significantly lower in the BF of birds infected with UK661 compared to F52/70 (pUK661) also showed a reduced level of IFNα and IL-8 compared to cells infected with a chimeric virus carrying the F52/70-VP4 gene (PBG98-VP4F52/70), and birds infected with PBG98-VP4UK661also had a reduced expression of IFNα in the BF compared to birds infected with PBG98-VP4F52/70. Taken together, these data demonstrate that UK661 induced the expression of lower levels of anti-viral type I IFN and proinflammatory genes than the classical strainin vitroandin vivoand this was, in part, due to strain-dependent differences in the VP4 protein.
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- 2019
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16. The Stronger Downregulation of
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Katherine L, Dulwich, Amin, Asfor, Alice, Gray, Efstathios S, Giotis, Michael A, Skinner, and Andrew J, Broadbent
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IBDV ,Down-Regulation ,Birnaviridae Infections ,Antiviral Agents ,Infectious bursal disease virus ,cytokines ,virulence ,Cellular and Infection Microbiology ,inflammation ,VP4 ,Animals ,Chickens ,Poultry Diseases ,type I IFN ,Original Research - Abstract
IBDV is economically important to the poultry industry. Very virulent (vv) strains cause higher mortality rates than other strains for reasons that remain poorly understood. In order to provide more information on IBDV disease outcome, groups of chickens (n = 18) were inoculated with the vv strain, UK661, or the classical strain, F52/70. Birds infected with UK661 had a lower survival rate (50%) compared to F52/70 (80%). There was no difference in peak viral replication in the bursa of Fabricius (BF), but the expression of chicken IFNα, IFNβ, MX1, and IL-8 was significantly lower in the BF of birds infected with UK661 compared to F52/70 (p < 0.05) as quantified by RTqPCR, and this trend was also observed in DT40 cells infected with UK661 or F52/70 (p < 0.05). The induction of expression of type I IFN in DF-1 cells stimulated with polyI:C (measured by an IFN-β luciferase reporter assay) was significantly reduced in cells expressing ectopic VP4 from UK661 (p < 0.05), but was higher in cells expressing ectopic VP4 from F52/70. Cells infected with a chimeric recombinant IBDV carrying the UK661-VP4 gene in the background of PBG98, an attenuated vaccine strain that induces high levels of innate responses (PBG98-VP4UK661) also showed a reduced level of IFNα and IL-8 compared to cells infected with a chimeric virus carrying the F52/70-VP4 gene (PBG98-VP4F52/70) (p < 0.01), and birds infected with PBG98-VP4UK661 also had a reduced expression of IFNα in the BF compared to birds infected with PBG98-VP4F52/70 (p < 0.05). Taken together, these data demonstrate that UK661 induced the expression of lower levels of anti-viral type I IFN and proinflammatory genes than the classical strain in vitro and in vivo and this was, in part, due to strain-dependent differences in the VP4 protein.
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- 2019
17. Detection of antibodies against a conserved capsid epitope as the basis of a novel universal serological test for foot-and-mouth disease
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Anna B. Ludi, Ginette Wilsden, Santina Grazioli, Stephen Berryman, Satya Parida, Krupali Parekh, Donald P. King, Amin S. Asfor, Toby Tuthill, N. Howe, and Emiliana Brocchi
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Serotype ,medicine.drug_class ,viruses ,biochemical phenomena, metabolism, and nutrition ,Biology ,Monoclonal antibody ,Virology ,Epitope ,Virus ,Serology ,Capsid ,Antigen ,medicine ,Seroconversion - Abstract
Diagnostic tests for foot-and-mouth disease (FMD) include the detection of antibodies against either the viral non-structural proteins or the capsid. The detection of antibodies against the structural proteins (SP) of the capsid can be used to monitor seroconversion in both infected and vaccinated animals. However, SP tests need to be tailored to the individual FMD virus serotype and their sensitivity performances may be affected by antigenic variability within each serotype and mismatching between tests reagents. As a consequence, FMD Reference Laboratories need to maintain contingency to employ multiple type-specific assays for large-scale serological surveillance and post-vaccination monitoring in the event of FMD outbreaks. In this study, a highly conserved region in the N terminus of FMDV capsid protein VP2 (VP2N) was characterised using a panel of intertypic-reactive monoclonal antibodies. This revealed a universal epitope in VP2N which could be used as a peptide antigen to detect FMDV-specific antibodies against all types of the virus. A VP2-peptide ELISA (VP2-ELISA) was optimised using experimental and reference antisera from immunized, convalescent and negative animals (n=172). The VP2-ELISA is universal, simple and provided sensitive (98.6 %) and specific (93%) detection of antibodies to all FMDV strains used in this study. We anticipate that this SP test could have utility for sero-surveillance during virus incursions in FMD-free countries and as an additional screening tool to assess FMD virus circulation in endemic countries.
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- 2019
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18. In vivo and ex vivo models of infectious bursal disease virus (IBDV) in inbred chicken lines differing in their resistance to the disease
- Author
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Kate Dulwich, Amin S. Asfor, and Andrew J. Broadbent
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animal structures ,Virulence ,Biology ,medicine.disease ,Virology ,Virus ,Fold change ,Infectious bursal disease ,Viral replication ,In vivo ,medicine ,General Materials Science ,Bursa of Fabricius ,Ex vivo - Abstract
Infectious bursal disease virus (IBDV) targets B cells in the bursa of Fabricius (BF), causing immunosuppression in chickens and mortality. Susceptibility differs between inbred chickens, with 0 % mortality in ‘resistant’ lines and up to 80 % mortality in ‘susceptible’ lines. However, the mechanism of disease resistance is not understood. In order to address this, chickens (n=18) from three ‘resistant’ lines (15, C and O) and one ‘susceptible’ line (W) were infected with the very virulent IBDV strain, UK661. Clinical scores were recorded and tissues harvested at necropsy on day one, two and three post-infection for RNA extraction and virus titration, compared to non-infected controls. Interestingly, within a given line, we observed a range of symptoms, with some individuals experiencing more severe disease than others, despite no difference in viral replication. Line 15 was the least susceptible to disease based on the average clinical scores (3.2 (15), 5.7 (C), 4.8 (O) and 4.7 (W)) and the percentage of birds with a clinical score of 2 or above (17 % (15), 100 % (C), 83 % (O) and 83 % (W)). The average peak virus replication was also significantly lower in line 15 birds (6.3 log10 fold change) compared to lines C or O (7.0 and 6.8 log10 fold change) (P
- Published
- 2019
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19. Absorption characteristics of composite materials reinforced by zinc oxide nanoparticles and Kevlar fibres
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M A Rajab, A K Asfor, and Z A Abed
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Materials science ,Formaldehyde ,chemistry.chemical_element ,Nanoparticle ,Epoxy ,Zinc ,Kevlar ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Phenol ,Composite material ,Absorption (chemistry) - Abstract
The research aims to study the effect of zinc oxide nanoparticles and Kevlar fibres on the absorption property of composite materials consisting of epoxy resins and phenol formaldehyde in different proportions. The results showed: Epoxy resins are not absorbed without adding phenol formaldehyde, which means an increase in the absorption property with an increases the proportion of phenol formaldehyde increases. The fibre strengthening also increases the absorption, so Kevlar with fibres gave the highest absorption; However, the absorption property decreases when the compounds are enhanced with zinc oxide nanoparticles as compared to the effects seen in the non-reinforced compounds.
- Published
- 2021
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20. The conserved N-terminus of human rhinovirus capsid protein VP4 contains membrane pore-forming activity and is a target for neutralizing antibodies
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Tobias J. Tuthill, Anusha Panjwani, and Amin S. Asfor
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0301 basic medicine ,Rhinovirus ,Membrane permeability ,Picornavirus ,Short Communication ,viruses ,Amino Acid Motifs ,Biology ,Antibodies, Viral ,Virus ,03 medical and health sciences ,0302 clinical medicine ,Virology ,Membrane activity ,Humans ,030212 general & internal medicine ,Conserved Sequence ,Myristoylation ,Picornaviridae Infections ,Animal ,myristoylation ,Cell Membrane ,virus diseases ,RNA ,biology.organism_classification ,Antibodies, Neutralizing ,non-enveloped virus ,picornavirus ,030104 developmental biology ,membrane permeability ,Capsid ,Cytoplasm ,viroporin ,Capsid Proteins ,Positive-strand RNA Viruses ,virus cell entry - Abstract
Human rhinovirus is the causative agent of the common cold and belongs to the non-enveloped picornavirus family. A trigger such as receptor binding or low pH initiates conformational changes in the capsid that allow the virus to attach to membranes and form a pore for the translocation of viral RNA into the cytoplasm. We previously showed that recombinant capsid protein VP4 was able to form membrane pores. In this study, we show the N-terminus but not C-terminus of VP4 formed pores with properties similar to full-length VP4 and consistent with the size required for transfer of RNA. Sera against the N-terminus but not C-terminus of VP4 were shown to neutralize virus infectivity. Together, this suggests that the N-terminus of VP4 is responsible for membrane activity. This study contributes to an improved understanding of the mechanisms for involvement of VP4 in entry and its potential as an antiviral target.
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- 2016
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21. Wear Resistance Of Hybrid Blend Reinforced By Fibers With Different Mixing Ratio
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Dr. Mustafa Ahmed. Rajab, Zainab Saad Mahdi, and Amera Kanan Asfor
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The research aims to study the mechanical properties (Hardness and Wear Resistance) of composite materials (epoxy resins with phenolic formaldehyde resin) supported by graphite or silica particles or both, and reinforced with carbon fibers of a standard format (-90, 0, +90).easy
- Published
- 2018
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22. An Ex Vivo Chicken Primary Bursal-cell Culture Model to Study Infectious Bursal Disease Virus Pathogenesis
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Amin S. Asfor, Alice Gray, Katherine L Dulwich, Andrew J. Broadbent, and Venugopal Nair
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0301 basic medicine ,animal structures ,CD40 ,biology ,General Immunology and Microbiology ,General Chemical Engineering ,General Neuroscience ,Virulence ,medicine.disease ,Virology ,Virus ,General Biochemistry, Genetics and Molecular Biology ,3. Good health ,Infectious bursal disease ,03 medical and health sciences ,030104 developmental biology ,Viral replication ,Cell culture ,biology.protein ,medicine ,Bursa of Fabricius ,Ex vivo - Abstract
Infectious bursal disease virus (IBDV) is a birnavirus of economic importance to the poultry industry. The virus infects B cells, causing morbidity, mortality, and immunosuppression in infected birds. In this study, we describe the isolation of chicken primary bursal cells from the bursa of Fabricius, the culture and infection of the cells with IBDV, and the quantification of viral replication. The addition of chicken CD40 ligand significantly increased cell proliferation fourfold over six days of culture and significantly enhanced cell viability. Two strains of IBDV, a cell-culture adapted strain, D78, and a very virulent strain, UK661, replicated well in the ex vivo cell cultures. This model will be of use in determining how cells respond to IBDV infection and will permit a reduction in the number of infected birds used in IBDV pathogenesis studies. The model can also be expanded to include other viruses and could be applied to different species of birds.
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- 2018
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23. Prediction and characterization of novel epitopes of serotype A foot-and-mouth disease viruses circulating in East Africa using site-directed mutagenesis
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Richard Reeve, Daniel T. Haydon, Amin S. Asfor, Satya Parida, David J. Paton, Mana Mahapatra, and Fufa Dawo Bari
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RNA viruses ,Serotype ,viruses ,Biology ,Antibodies, Viral ,Serogroup ,Epitope ,Neutralization ,Virus ,Cell Line ,Epitopes ,03 medical and health sciences ,Neutralization Tests ,Virology ,Animals ,030304 developmental biology ,0303 health sciences ,Animal ,030306 microbiology ,virus diseases ,Africa, Eastern ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Antibodies, Neutralizing ,Standard ,Reverse Genetics ,Reverse genetics ,3. Good health ,Capsid ,Foot-and-Mouth Disease Virus ,Mutagenesis, Site-Directed ,biology.protein ,Capsid Proteins ,Foot-and-mouth disease virus ,Antibody - Abstract
Epitopes on the surface of the foot-and-mouth disease virus (FMDV) capsid have been identified by monoclonal antibody (mAb) escape mutant studies leading to the designation of four antigenic sites in serotype A FMDV. Previous work focused on viruses isolated mainly from Asia, Europe and Latin America. In this study we report on the prediction of epitopes in African serotype A FMDVs and testing of selected epitopes using reverse genetics. Twenty-four capsid amino acid residues were predicted to be of antigenic significance by analysing the capsid sequences (n = 56) using in silico methods, and six residues by correlating capsid sequence with serum–virus neutralization data. The predicted residues were distributed on the surface-exposed capsid regions, VP1–VP3. The significance of residue changes at eight of the predicted epitopes was tested by site-directed mutagenesis using a cDNA clone resulting in the generation of 12 mutant viruses involving seven sites. The effect of the amino acid substitutions on the antigenic nature of the virus was assessed by virus neutralization (VN) test. Mutations at four different positions, namely VP1-43, VP1-45, VP2-191 and VP3-132, led to significant reduction in VN titre (P value = 0.05, 0.05, 0.001 and 0.05, respectively). This is the first time, to our knowledge, that the antigenic regions encompassing amino acids VP1-43 to -45 (equivalent to antigenic site 3 in serotype O), VP2-191 and VP3-132 have been predicted as epitopes and evaluated serologically for serotype A FMDVs. This identifies novel capsid epitopes of recently circulating serotype A FMDVs in East Africa.
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- 2015
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24. The cellular chaperone heat shock protein 90 is required for foot-and-mouth disease virus capsid precursor processing and assembly of capsid pentamers
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Stephen Curry, Amin S. Asfor, Joseph Newman, Terry Jackson, Stephen Berryman, and Tobias J. Tuthill
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0301 basic medicine ,EMPTY CAPSIDS ,Picornavirus ,viruses ,virus assembly ,polyprotein processing ,Virus Replication ,MAMMALIAN-CELLS ,Cricetinae ,Benzoquinones ,2. Zero hunger ,biology ,3C PROTEASE ,3C Viral Proteases ,virus diseases ,POLIOVIRUS P1 PRECURSOR ,11 Medical And Health Sciences ,Cell biology ,Cysteine Endopeptidases ,Capsid ,INFECTED-CELLS ,RNA, Viral ,Foot-and-mouth disease virus ,Viral genome replication ,Life Sciences & Biomedicine ,Cell Survival ,Pentamer ,Lactams, Macrocyclic ,Immunology ,VIRAL REPLICATION ,Microbiology ,Cell Line ,Viral Proteins ,03 medical and health sciences ,Viral entry ,Virology ,Animals ,HSP90 Heat-Shock Proteins ,Protein Precursors ,3-DIMENSIONAL STRUCTURE ,Science & Technology ,Cell-Free System ,foot-and-mouth disease virus ,Structure and Assembly ,Isoxazoles ,Resorcinols ,biochemical phenomena, metabolism, and nutrition ,06 Biological Sciences ,biology.organism_classification ,SUBVIRAL PARTICLES ,hsp90 ,030104 developmental biology ,picornavirus ,Viral replication ,Foot-and-Mouth Disease ,Insect Science ,Chaperone (protein) ,biology.protein ,Capsid Proteins ,07 Agricultural And Veterinary Sciences ,VP1/2A JUNCTION ,Protein Processing, Post-Translational ,HSP90 MOLECULAR CHAPERONE ,Molecular Chaperones - Abstract
Productive picornavirus infection requires the hijacking of host cell pathways to aid with the different stages of virus entry, synthesis of the viral polyprotein, and viral genome replication. Many picornaviruses, including foot-and-mouth disease virus (FMDV), assemble capsids via the multimerization of several copies of a single capsid precursor protein into a pentameric subunit which further encapsidates the RNA. Pentamer formation is preceded by co- and posttranslational modification of the capsid precursor (P1-2A) by viral and cellular enzymes and the subsequent rearrangement of P1-2A into a structure amenable to pentamer formation. We have developed a cell-free system to study FMDV pentamer assembly using recombinantly expressed FMDV capsid precursor and 3C protease. Using this assay, we have shown that two structurally different inhibitors of the cellular chaperone heat shock protein 90 (hsp90) impeded FMDV capsid precursor processing and subsequent pentamer formation. Treatment of FMDV permissive cells with the hsp90 inhibitor prior to infection reduced the endpoint titer by more than 10-fold while not affecting the activity of a subgenomic replicon, indicating that translation and replication of viral RNA were unaffected by the drug. IMPORTANCE FMDV of the Picornaviridae family is a pathogen of huge economic importance to the livestock industry due to its effect on the restriction of livestock movement and necessary control measures required following an outbreak. The study of FMDV capsid assembly, and picornavirus capsid assembly more generally, has tended to be focused upon the formation of capsids from pentameric intermediates or the immediate cotranslational modification of the capsid precursor protein. Here, we describe a system to analyze the early stages of FMDV pentameric capsid intermediate assembly and demonstrate a novel requirement for the cellular chaperone hsp90 in the formation of these pentameric intermediates. We show the added complexity involved for this process to occur, which could be the basis for a novel antiviral control mechanism for FMDV.
- Published
- 2017
25. Fragment-derived inhibitors of human N-myristoyltransferase block capsid assembly and replication of the common cold virus
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Amin S. Asfor, Robin J. Leatherbarrow, Iva Hopkins-Navratilova, Aurelie Mousnier, Sean Robinson, Anabel Guedán, Inmaculada Pérez-Dorado, Andrew Simon Bell, Joseph Newman, Anthony J. Wilkinson, Markus Ritzefeld, Roberto Solari, Edward W. Tate, J.A. Hutton, Dawid Swieboda, Sebastian L. Johnston, Tobias J. Tuthill, James A. Brannigan, Julia Morales-Sanfrutos, Medical Research Council (MRC), Wellcome Trust, Asthma UK, GlaxoSmithKline Services Unlimited, and Cancer Research UK
- Subjects
0301 basic medicine ,Viral capsid assembly ,Rhinovirus ,Chemistry, Multidisciplinary ,General Chemical Engineering ,viruses ,PREVENTS ,medicine.disease_cause ,Virus Replication ,01 natural sciences ,INFECTION ,Enzyme Inhibitors ,Cytotoxicity ,Molecular Structure ,Chemistry ,Poliovirus ,NMT2 ,MYRISTOYLATION ,3. Good health ,Capsid ,Physical Sciences ,PROTEOMICS ,03 Chemical Sciences ,Antiviral Agents ,Virus ,Article ,03 medical and health sciences ,Inhibitory Concentration 50 ,SDG 3 - Good Health and Well-being ,medicine ,Humans ,Myristoylation ,Science & Technology ,CYSTIC-FIBROSIS ,010405 organic chemistry ,Virus Assembly ,Organic Chemistry ,General Chemistry ,Virology ,0104 chemical sciences ,030104 developmental biology ,CELLS ,ASTHMA ,Linker ,Acyltransferases ,HeLa Cells - Abstract
Rhinoviruses (RVs) are the pathogens most often responsible for the common cold, and are a frequent cause of exacerbations in asthma, chronic obstructive pulmonary disease and cystic fibrosis. Here we report the discovery of IMP-1088, a picomolar dual inhibitor of the human N-myristoyltransferases NMT1 and NMT2, and use it to demonstrate that pharmacological inhibition of host-cell N-myristoylation rapidly and completely prevents rhinoviral replication without inducing cytotoxicity. The identification of cooperative binding between weak-binding fragments led to rapid inhibitor optimization through fragment reconstruction, structure-guided fragment linking and conformational control over linker geometry. We show that inhibition of the co-translational myristoylation of a specific virus-encoded protein (VP0) by IMP-1088 potently blocks a key step in viral capsid assembly, to deliver a low nanomolar antiviral activity against multiple RV strains, poliovirus and foot and-mouth disease virus, and protection of cells against virus-induced killing, highlighting the potential of host myristoylation as a drug target in picornaviral infections.
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- 2017
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26. Recombinant pestivirus E2 glycoproteins prevent viral attachment to permissive and non permissive cells with different efficiency
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P.R. Wakeley, David J. Paton, A.S. Asfor, and Trevor W. Drew
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Cancer Research ,viruses ,Virus Attachment ,Heterologous ,Spodoptera ,Virus ,law.invention ,Viral Envelope Proteins ,law ,Virology ,Sf9 Cells ,Animals ,Pathogen ,Glycoproteins ,Infectivity ,chemistry.chemical_classification ,biology ,Pestivirus ,biology.organism_classification ,Recombinant Proteins ,Infectious Diseases ,chemistry ,Recombinant DNA ,biology.protein ,Antibody ,Glycoprotein - Abstract
Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen, which like other pestiviruses has similar molecular biological features to hepaciviruses, including human Hepatitis C virus. The pestivirus E2 glycoproteins are the major target for virus-neutralising antibodies, as well as playing a role in receptor binding and host range restriction. In this study, recombinant E2 glycoproteins (rE2) derived from three different pestivirus species were examined for their inhibitory effects on pestivirus infectivity in cell culture. Histidine-tagged rE2 glycoproteins of BVDV type 2 strain 178003, BVDV type 1 strain Oregon C24V and CSFV strain Alfort 187 were produced in Spodoptera frugiperda insect cells and purified under native conditions. The ability of rE2 glycoprotein to inhibit the infection of permissive cells by both homologous and heterologous virus was compared, revealing that the inhibitory effects of rE2 glycoproteins correlated with the predicted similarity of the E2 structures in the recombinant protein and the test virus. This result suggests that the sequence and structure of E2 are likely to be involved in the host specificity of pestiviruses at their point of uptake into cells.
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- 2014
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27. Novel antibody binding determinants on the capsid surface of serotype O foot-and-mouth disease virus
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Sasmita Upadhyaya, Donald P. King, Mana Mahapatra, Nick J. Knowles, David J. Paton, and Amin S. Asfor
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Serotype ,viruses ,DNA Mutational Analysis ,Guinea Pigs ,Molecular Sequence Data ,Biology ,Antibodies, Viral ,Neutralization ,Epitope ,Virus ,Epitopes ,03 medical and health sciences ,Neutralization Tests ,Virology ,Animals ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,030306 microbiology ,virus diseases ,Sequence Analysis, DNA ,Positive-strand RNA ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Antibodies, Neutralizing ,Standard ,3. Good health ,Amino acid ,Capsid ,chemistry ,Foot-and-Mouth Disease Virus ,biology.protein ,Capsid Proteins ,Cattle ,Foot-and-mouth disease virus ,Antibody ,Animal viruses ,Protein Binding - Abstract
Five neutralizing antigenic sites have been described for serotype O foot-and-mouth disease viruses (FMDV) based on monoclonal antibody (mAb) escape mutant studies. However, a mutant virus selected to escape neutralization of mAb binding at all five sites was previously shown to confer complete cross-protection with the parental virus in guinea pig challenge studies, suggesting that amino acid residues outside the mAb binding sites contribute to antibody-mediated in vivo neutralization of FMDV. Comparison of the ability of bovine antisera to neutralize a panel of serotype O FMDV identified three novel putative sites at VP2-74, VP2-191 and VP3-85, where amino acid substitutions correlated with changes in sero-reactivity. The impact of these positions was tested using site-directed mutagenesis to effect substitutions at critical amino acid residues within an infectious copy of FMDV O1 Kaufbeuren (O1K). Recovered viruses containing additional mutations at VP2-74 and VP2-191 exhibited greater resistance to neutralization with both O1K guinea pig and O BFS bovine antisera than a virus that was engineered to include only mutations at the five known antigenic sites. The changes at VP2-74 and VP3-85 are adjacent to critical amino acids that define antigenic sites 2 and 4, respectively. However VP2-191 (17 Å away from VP2-72), located at the threefold axis and more distant from previously identified antigenic sites, exhibited the most profound effect. These findings extend our knowledge of the surface features of the FMDV capsid known to elicit neutralizing antibodies, and will improve our strategies for vaccine strain selection and rational vaccine design.
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- 2014
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28. [Untitled]
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Luana Gondim de Castro, Bruno Furtado-Lima, Laércia Ferreira Martins, Vinicius Diniz Arcelino do Ceará, Alessandro Pontes-Arruda, and Ivna Fernandes Queiroz-Asfor
- Subjects
medicine.medical_specialty ,law ,business.industry ,medicine ,Critical Care and Intensive Care Medicine ,Intensive care medicine ,business ,Intensive care unit ,law.invention - Published
- 2012
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29. Efeito Antibacteriano do Carvacrol e Timol nos Materiais Dentários: uma Revisão de Literatura
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J F Costa, A L P Oliveira, Thyciana Rodrigues Ribeiro, F C M Chaves Filho, Marcelino Silva, Cristiane Sá Roriz Fonteles, Renata Asfor Rocha Carvalho Martins, and R B V Marinho
- Abstract
O objetivo desta revisão é descrever a atividade antimicrobiana dos Óleos Essenciais (OE’s) carvacrol e timol e suas aplicações nos materiais dentários.Foi realizada uma revisão de literatura, utilizando-se as bases de dados “Medline”, “Lilacs” e “SciELO”, os descritores “Anti-infecciosos”, “Thymol”, “Oils, Volatile”, tendo sido encontrados 571 artigos e selecionados 25 publicados entre 2007 e 2017, escritos em inglês, português e/ou espanhol. Relatos de casos foram excluídos. As pesquisas com materiais dentários contendo produtos naturais aumentaram devido à busca por novas substâncias com maior atividade farmacológica, menor toxicidade e maior biocompatibilidade. Dentre os estudos levantados, os OE’s carvacrol e timol se mostraram mais prevalentes. A atividade antibacteriana destes compostos pode ocorrer pela desestabilização da parede celular, aumento da permeabilidade da membrana citoplasmática e pela alteração de vários sistemas enzimáticos, incluindo aqueles envolvidos na produção de energia celular e na síntese de componentes estruturais. Entre as possibilidades de aplicações, estes OE’s foram empregados em soluções irrigadoras para canais radiculares, dentifrícios, exaguatórios bucais e vernizes, demonstrando eficácia antibacteriana. Portanto, estudos desses produtos naturais na odontologia são realizados, visando à obtenção de materiais dentários com agentes antimicrobianos que possibilitem a prevenção e tratamento de doenças bucais, com poucos efeitos colaterais indesejáveis e fácil acesso à população.Palavras-chave: Anti-Infecciosos. Thymol. Oils. Volatile.
- Published
- 2018
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30. Implicações da Adição de Própolis nas Propriedades Físico-Mecânicas do Cimento de Ionômero de Vidro
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Sara Maria Silva, Thyciana Rodrigues Ribeiro, Cristiane Sá Roriz Fonteles, A L P Oliveira, F C M Chaves Filho, Renata Asfor Rocha Carvalho Martins, and J F Costa
- Abstract
O objetivo do presente trabalho foi realizar uma revisão da literatura sobre as propriedades físico-mecânicas do cimento de ionômero de vidro (CIV) adicionado de própolis. Para essa finalidade, foi efetuada busca no banco de dados Medline/Pubmed, utilizando os descritores “propolis”, “glass ionomer cements” e “dental materials”, na língua inglesa, no período de 2009 a 2017. Foi encontrado um total de 7 artigos, dos quais foram selecionados 6 após leitura de títulos e resumos, considerando o idioma, o período e o grau de envolvimento do artigo com o tema em questão como critérios de inclusão/exclusão. Como resultados, verificou-se que, embora os estudos apontem melhora dos efeitos antimicrobianos a partir da associação entre a própolis e o CIV, seus efeitos sobre as propriedades físico-mecânicas do cimento ainda não são totalmente conhecidos. Nos artigos selecionados foram avaliadas propriedades como resistência à compressão, solubilidade e sorção de água, com alguns resultados controversos. Tendo em vista que o cimento de ionômero de vidro é um material muito útil e versátil na Odontologia e que a própolis tem sido cada vez mais adicionada a ele em situações como no tratamento restaurador atraumático e na cimentação de bandas ortodônticas a fim de potencializar a ação antimicrobiana dos CIVs, ainda são necessárias pesquisas adicionais para melhor compreensão dessas peculiaridades.Palavras-chave: Propolis. Glass Ionomer Cements. Dental Materials.
- Published
- 2018
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31. Aplicabilidade de Óleos Essenciais em Materiais Dentários: uma Revisão de Literatura
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Cristiane Sá Roriz Fonteles, Renata Asfor Rocha Carvalho Martins, A L P Oliveira, Thyciana Rodrigues Ribeiro, F C M Chaves Filho, Marcelino Silva, and J F Costa
- Abstract
O objetivo do presente trabalho foi realizar uma revisão de literatura sobre as propriedades terapêuticas dos óleos essenciais (OEs) em Odontologia visando sua aplicabilidade em materiais dentários com ação antimicrobiana. Para tanto, foi realizada uma pesquisa nas bases de dados eletrônicas MEDLINE e BVS, utilizando os descritores Oils, Volatile, Dental Materials e Anti-Infective Agents em português e inglês. Foram encontrados 51 artigos publicados no período de 2007 a 2017 e 15 foram selecionados através de leitura de títulos e resumos, excluindo-se relatos de casos. Durante a análise dos artigos, destacaram-se os OEs de Lippia sidoides, timol, carvacrol e Rosmarinus officinalis que, além de serem de fácil obtenção, apresentaram atividade antibacteriana e antifúngica significativa contra S. Mutans, C. Albicans e E. Faecalis. Essas propriedades apresentadas pelos OEs propiciaram potenciais aplicabilidades em dentifrícios, enxaguatórios bucais, condicionadores de tecido, aplicações intracanal, adesivos e vernizes conferindo-lhes características antimicrobianas importantes no controle dos patógenos orais agindo de forma versátil em diferentes sítios a depender do local de aplicação do material. Importante destacar que a validação científica, clínica e comercial da atividade terapêutica dos OEs em materiais dentários são essenciais para possibilitar avanços na odontologia preventiva e restauradora, possibilitando, alternativas naturais, com poucos efeitos colaterais e que possam melhorar a qualidade de vida dos pacientes.Palavras-chave: Oils. Volatile. Dental Materials. Anti-Infective Agents.
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- 2018
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32. Uma Visão Processual dos Direitos Fundamentais
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Tiago Asfor Rocha Lima
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A temática que se objeta tratar envolve por natureza a análise do conceito de jurisdição constitucional, especialmente tendo em vista a perspectiva dos direitos fundamentais como aqueles direitos protegidos processualmente e dotados de um status especial por cada Constituição, características estas que os distinguem dos demais direitos positivados no restante do ordenamento jurídico.
- Published
- 2004
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33. ANALISANDO PESSOAS E FATOS
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Cesar Asfor Rocha
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- 2009
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34. O JUIZ E O MINISTÉRIO PÚBLICO
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Cesar Asfor Rocha
- Published
- 2009
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35. ATÉ BREVE, COLEGA!
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Cesar Asfor Rocha
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- 2009
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36. O JUIZ E A FUNÇÃO DE JULGAR
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Cesar Asfor Rocha
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- 2009
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37. O INGRESSO NA MAGISTRATURA
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Cesar Asfor Rocha
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- 2009
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38. O JUIZ E OS ADVOGADOS
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Cesar Asfor Rocha
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- 2009
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39. O JUIZ E A IMPRENSA
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Cesar Asfor Rocha
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- 2009
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40. O JUIZ E AS RELAÇÕES COM OS COLEGAS
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Cesar Asfor Rocha
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- 2009
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41. O JUIZ, OS TRIBUNAIS E A JURISPRUDÊNCIA
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Cesar Asfor Rocha
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- 2009
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42. O JUIZ E AS EXPECTATIVAS DA SOCIEDADE
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Cesar Asfor Rocha
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- 2009
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43. O SABER E OS SABERES DO JUIZ
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Cesar Asfor Rocha
- Published
- 2009
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44. INTERPRETANDO AS LEIS COM JUSTIÇA
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Cesar Asfor Rocha
- Published
- 2009
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45. O JUIZ, A POLÍTICA E OS POLÍTICOS
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Cesar Asfor Rocha
- Published
- 2009
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46. INTRODUÇÃO
- Author
-
Cesar Asfor Rocha
- Published
- 2009
- Full Text
- View/download PDF
47. A LINGUAGEM DO JUIZ
- Author
-
Cesar Asfor Rocha
- Published
- 2009
- Full Text
- View/download PDF
48. A FAMÍLIA E OS AMIGOS
- Author
-
Cesar Asfor Rocha
- Published
- 2009
- Full Text
- View/download PDF
49. Healthy Caregivers-Healthy Children (HC2): A Childcare Center Based Obesity Prevention
- Author
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Kris Arheart, L. Asfor, Ruby Natale, Alan M. Delamater, Sarah E. Messiah, and Susan B. Uhlhorn
- Subjects
Obesity prevention ,Gerontology ,Nutrition and Dietetics ,business.industry ,Medicine (miscellaneous) ,Medicine ,Center (algebra and category theory) ,business - Published
- 2013
- Full Text
- View/download PDF
50. 105. Development of an ELISA for the differential serological diagnosis of pestivirus infections in pigs
- Author
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S.J. Moore, P.R. Wakeley, A. Asfor, and T. Sandvik
- Subjects
General Veterinary ,Pestivirus infections ,Biology ,Virology ,Serology - Published
- 2003
- Full Text
- View/download PDF
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