1
|
Guan B, Hong H, Kim M, Lu J, Moore MD. Evaluating the Potential of Ozone Microbubbles for Inactivation of Tulane Virus, a Human Norovirus Surrogate. ACS OMEGA 2024; 9:23184-23192. [PMID: 38854534 PMCID: PMC11154720 DOI: 10.1021/acsomega.3c08396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 05/11/2024] [Accepted: 05/15/2024] [Indexed: 06/11/2024]
Abstract
This study investigated the efficacy of low-dose ozone microbubble solution and conventional aqueous ozone as inactivation agents against Tulane virus samples in water over a short period of time. Noroviruses are the primary cause of foodborne illnesses in the US, and the development of effective inactivation agents is crucial. Ozone has a high oxidizing ability and naturally decomposes to oxygen, but it has limitations due to its low dissolution rate, solubility, and stability. Ozone microbubbles have been promising in enhancing inactivation, but little research has been done on their efficacy against noroviruses. The study examined the influence of the dissolved ozone concentration, inactivation duration, and presence of organic matter during inactivation. The results showed that ozone microbubbles had a longer half-life (14 ± 0.81 min) than aqueous ozone (3 ± 0.35 min). After 2, 10, and 20 min postgeneration, the ozone concentration of microbubbles naturally decreased from 4 ppm to 3.2 ± 0.2, 2.26 ± 0.19, and 1.49 ± 0.23 ppm and resulted in 1.43 ± 0.44, 0.88 ± 0.5, and 0.68 ± 0.53 log10 viral reductions, respectively, while the ozone concentration of aqueous ozone decreased from 4 ppm to 2.52 ± 0.07, 0.43 ± 0.05, and 0.09 ± 0.01 ppm and produced 0.8 ± 0.28, 0.29 ± 0.41, and 0.16 ± 0.21 log10 reductions against Tulane virus, respectively (p = 0.0526), suggesting that structuring of ozone in the bubbles over the applied treatment conditions did not have a significant effect, though future study with continuous generation of ozone microbubbles is needed.
Collapse
Affiliation(s)
- Bozhong Guan
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Haknyeong Hong
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Minji Kim
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Jiakai Lu
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Matthew D. Moore
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, United States
| |
Collapse
|
2
|
Sun C, Huang P, Xu X, Vago FS, Li K, Klose T, Jiang XJ, Jiang W. The 2.6 Å Structure of a Tulane Virus Variant with Minor Mutations Leading to Receptor Change. Biomolecules 2024; 14:119. [PMID: 38254719 PMCID: PMC10813083 DOI: 10.3390/biom14010119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
Human noroviruses (HuNoVs) are a major cause of acute gastroenteritis, contributing significantly to annual foodborne illness cases. However, studying these viruses has been challenging due to limitations in tissue culture techniques for over four decades. Tulane virus (TV) has emerged as a crucial surrogate for HuNoVs due to its close resemblance in amino acid composition and the availability of a robust cell culture system. Initially isolated from rhesus macaques in 2008, TV represents a novel Calicivirus belonging to the Recovirus genus. Its significance lies in sharing the same host cell receptor, histo-blood group antigen (HBGA), as HuNoVs. In this study, we introduce, through cryo-electron microscopy (cryo-EM), the structure of a specific TV variant (the 9-6-17 TV) that has notably lost its ability to bind to its receptor, B-type HBGA-a finding confirmed using an enzyme-linked immunosorbent assay (ELISA). These results offer a profound insight into the genetic modifications occurring in TV that are necessary for adaptation to cell culture environments. This research significantly contributes to advancing our understanding of the genetic changes that are pivotal to successful adaptation, shedding light on fundamental aspects of Calicivirus evolution.
Collapse
Affiliation(s)
- Chen Sun
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA (F.S.V.)
| | - Pengwei Huang
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Xueyong Xu
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA (F.S.V.)
| | - Frank S. Vago
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA (F.S.V.)
| | - Kunpeng Li
- School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA (F.S.V.)
| | - Xi Jason Jiang
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Wen Jiang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA (F.S.V.)
| |
Collapse
|
3
|
Bernardy C, Malley J. Impacts of Surface Characteristics and Dew Point on the Blue-Light (BL 405) Inactivation of Viruses. Microorganisms 2023; 11:2638. [PMID: 38004651 PMCID: PMC10673487 DOI: 10.3390/microorganisms11112638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
The increased prevalence of multidrug-resistant organisms (MDROs), healthcare associated infections (HAIs), and the recent COVID-19 pandemic has caused the photoinactivation industry to explore alternative wavelengths. Blue light (BL405) has gained significant interest as it is much less harmful to the skin and eyes than traditional germicidal wavelengths; therefore, in theory, it can be used continuously with human exposure. At present, the viricidal effects of BL405 are largely unknown as the literature predominately addresses bacterial disinfection performed with this wavelength. This work provides novel findings to the industry, reporting on the virucidal effects of BL405 on surfaces. This research utilizes three surfaces: ceramic, PTFE, and stainless steel. The efficacy of BL405 inactivation varied by surface type, which was due to surface characteristics, such as the contact angle, porosity, zeta potential, and reflectivity. Additionally, the effect of the dew point on BL405 inactivation efficacy was determined. This research is the first to study the effects of the dew point on the virucidal effectiveness of BL405 surface inactivation. The effects of the dew point were significant for all surfaces and the control experiments. The high-dew-point conditions (18 °C) yielded higher levels of BL405 inactivation and viral degradation for the experiments and controls, respectively.
Collapse
Affiliation(s)
| | - James Malley
- Department of Civil and Environmental Engineering, College of Engineering & Physical Sciences, University of New Hampshire, Durham, NH 03824, USA;
| |
Collapse
|
4
|
Huang J, Park GW, Jones RM, Fraser AM, Vinjé J, Jiang X. Efficacy of EPA-registered disinfectants against two human norovirus surrogates and Clostridioides difficile endospores. J Appl Microbiol 2022; 132:4289-4299. [PMID: 35279925 PMCID: PMC9119914 DOI: 10.1111/jam.15524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 11/27/2022]
Abstract
AIMS To determine the efficacy of a panel of nine EPA-registered disinfectants against two human norovirus (HuNoV) surrogates (feline calicivirus [FCV] and Tulane virus [TuV]) and Clostridioides difficile endospores. METHODS AND RESULTS Nine EPA-registered products, five of which contained H2 O2 as active ingredient, were tested against infectious FCV, TuV and C. difficile endospores using two ASTM methods, a suspension and carrier test. Efficacy claims against FCV were confirmed for 8 of 9 products. The most efficacious product containing H2 O2 as ingredient achieved a >5.1 log reduction of FCV and >3.1 log reduction of TuV after 5 min, and >6.0 log reduction of C. difficile endospores after 10 min. Of the five products containing H2 O2 , no strong correlation (R2 = 0.25, p = 0.03) was observed between disinfection efficacy and H2 O2 concentration. Addition of 0.025% ferrous sulphate to 1% H2 O2 solution improved efficacy against FCV, TuV and C. difficile. CONCLUSION Disinfectants containing H2 O2 are the most efficacious disinfection products against FCV, TuV and C. difficile endospores. Product formulation, rather than the concentration of H2 O2 in a product, impacts the efficacy of a disinfection product. SIGNIFICANCE AND IMPACT OF STUDY H2 O2 -based disinfectants are efficacious against surrogate viruses for HuNoV and C. difficile endospores.
Collapse
Affiliation(s)
- Jinge Huang
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, South Carolina, USA
| | - Geun Woo Park
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Rachael M. Jones
- Department of Family and Preventive Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Angela M. Fraser
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, South Carolina, USA
| | - Jan Vinjé
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Xiuping Jiang
- Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, South Carolina, USA
| |
Collapse
|
5
|
Inactivation Mechanism and Efficacy of Grape Seed Extract for Human Norovirus Surrogate. Appl Environ Microbiol 2022; 88:e0224721. [PMID: 35465682 DOI: 10.1128/aem.02247-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proper disinfection of harvested food and water is critical to minimize infectious disease. Grape seed extract (GSE), a commonly used health supplement, is a mixture of plant-derived polyphenols. Polyphenols possess antimicrobial and antifungal properties, but antiviral effects are not well-known. Here we show that GSE outperformed chemical disinfectants (e.g., free chlorine and peracetic acids) in inactivating Tulane virus, a human norovirus surrogate. GSE induced virus aggregation, a process that correlated with a decrease in virus titers. This aggregation and disinfection were not reversible. Molecular docking simulations indicate that polyphenols potentially formed hydrogen bonds and strong hydrophobic interactions with specific residues in viral capsid proteins. Together, these data suggest that polyphenols physically associate with viral capsid proteins to aggregate viruses as a means to inhibit virus entry into the host cell. Plant-based polyphenols like GSE are an attractive alternative to chemical disinfectants to remove infectious viruses from water or food. IMPORTANCE Human noroviruses are major food- and waterborne pathogens, causing approximately 20% of all cases of acute gastroenteritis cases in developing and developed countries. Proper sanitation or disinfection are critical strategies to minimize human norovirus-caused disease until a reliable vaccine is created. Grape seed extract (GSE) is a mixture of plant-derived polyphenols used as a health supplement. Polyphenols are known for antimicrobial, antifungal, and antibiofilm activities, but antiviral effects are not well-known. In studies presented here, plant-derived polyphenols outperformed chemical disinfectants (i.e., free chlorine and peracetic acids) in inactivating Tulane virus, a human norovirus surrogate. Based on data from molecular assays and molecular docking simulations, the current model is that the polyphenols in GSE bind to the Tulane virus capsid, an event that triggers virion aggregation. It is thought that this aggregation prevents Tulane virus from entering host cells.
Collapse
|
6
|
Oh C, Kim K, Araud E, Wang L, Shisler JL, Nguyen TH. A novel approach to concentrate human and animal viruses from wastewater using receptors-conjugated magnetic beads. WATER RESEARCH 2022; 212:118112. [PMID: 35091223 DOI: 10.1016/j.watres.2022.118112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/07/2023]
Abstract
Viruses are present at low concentrations in wastewater; therefore, an effective method for concentrating virus particles is necessary for accurate wastewater-based epidemiology (WBE). We designed a novel approach to concentrate human and animal viruses from wastewater using porcine gastric mucin-conjugated magnetic beads (PGM-MBs). We systematically evaluated the performances of the PGM-MBs method (sensitivity, specificity, and robustness to environmental inhibitors) with six viral species, including Tulane virus (a surrogate for human norovirus), rotavirus, adenovirus, porcine coronavirus (transmissible gastroenteritis virus or TGEV), and two human coronaviruses (NL63 and SARS-CoV-2) in influent wastewater and raw sewage samples. We determined the multiplication factor (the ratio of genome concentration of the final solution to that of the initial solution) for the PGM-MBs method, which ranged from 1.3 to 64.0 depending on the viral species. Because the recovery efficiency was significantly higher when calculated with virus titers than it was with genome concentration, the PGM-MBs method could be an appropriate tool for assessing the risk to humans who are inadvertently exposed to wastewater contaminated with infectious viruses. Furthermore, PCR inhibitors were not concentrated by PGM-MBs, suggesting that this tool will be successful for use with environmental samples. In addition, the PGM-MBs method is cost-effective (0.5 USD/sample) and has a fast turnaround time (3 h from virus concentration to genome quantification). Thus, this method can be implemented in high throughput facilities. Because of its strong performance, intrinsic characteristics of targeting the infectious virus, robustness to wastewater, and adaptability to high throughput systems, the PGM-MBs method can be successfully applied to WBE and ultimately provides valuable public health information.
Collapse
Affiliation(s)
- Chamteut Oh
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, United States.
| | - Kyukyoung Kim
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, United States
| | - Elbashir Araud
- Holonyak Micro & Nanotechnology Lab, University of Illinois at Urbana-Champaign
| | - Leyi Wang
- Veterinary Diagnostic Laboratory and Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, United States
| | - Joanna L Shisler
- Department of Microbiology, University of Illinois at Urbana-Champaign, United States
| | - Thanh H Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, United States; Institute of Genomic Biology, University of Illinois at Urbana-Champaign, United States
| |
Collapse
|
7
|
Expression of quasi-equivalence and capsid dimorphism in the Hepadnaviridae. PLoS Comput Biol 2020; 16:e1007782. [PMID: 32310951 PMCID: PMC7192502 DOI: 10.1371/journal.pcbi.1007782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 04/30/2020] [Accepted: 03/10/2020] [Indexed: 12/13/2022] Open
Abstract
Hepatitis B virus (HBV) is a leading cause of liver disease. The capsid is an essential component of the virion and it is therefore of interest how it assembles and disassembles. The capsid protein is unusual both for its rare fold and that it polymerizes according to two different icosahedral symmetries, causing the polypeptide chain to exist in seven quasi-equivalent environments: A, B, and C in AB and CC dimers in T = 3 capsids, and A, B, C, and D in AB and CD dimers in T = 4 capsids. We have compared the two capsids by cryo-EM at 3.5 Å resolution. To ensure a valid comparison, the two capsids were prepared and imaged under identical conditions. We find that the chains have different conformations and potential energies, with the T = 3 C chain having the lowest. Three of the four quasi-equivalent dimers are asymmetric with respect to conformation and potential energy; however, the T = 3 CC dimer is symmetrical and has the lowest potential energy although its intra-dimer interface has the least free energy of formation. Of all the inter-dimer interfaces, the CB interface has the least area and free energy, in both capsids. From the calculated energies of higher-order groupings of dimers discernible in the lattices we predict early assembly intermediates, and indeed we observe such structures by negative stain EM of in vitro assembly reactions. By sequence analysis and computational alanine scanning we identify key residues and motifs involved in capsid assembly. Our results explain several previously reported observations on capsid assembly, disassembly, and dimorphism. Hepatitis B virus has infected approximately one third of the human population and causes almost 1 million deaths from liver disease annually. The capsid is a defining feature of a virus, distinct from host components, and therefore a target for intervention. Unusually for a virus, Hepatitis B assembles two capsids, with different geometries, from the same dimeric protein. Geometric principles dictate that the subunits in this system occupy seven different environments. From comparing the two capsids by cryo-electron microscopy at high resolution under the exact same conditions we find that the polypeptide chains adopt seven different conformations. We use these structures to calculate potential energies (analogous to elastic deformation or strain) for the individual chains, dimers, and several higher-order groupings discernible in the two lattices. We also calculate the binding energies between chains. We find that some groupings have substantially lower energy and are therefore potentially more stable, allowing us to predict likely intermediates on the two assembly pathways. We also observe such intermediates by electron microscopy of in vitro capsid assembly reactions. This is the first structural characterization of the early assembly intermediates of this important human pathogen.
Collapse
|
8
|
Dynamics in the murine norovirus capsid revealed by high-resolution cryo-EM. PLoS Biol 2020; 18:e3000649. [PMID: 32231352 PMCID: PMC7108717 DOI: 10.1371/journal.pbio.3000649] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 02/28/2020] [Indexed: 01/28/2023] Open
Abstract
Icosahedral viral capsids must undergo conformational rearrangements to coordinate essential processes during the viral life cycle. Capturing such conformational flexibility has been technically challenging yet could be key for developing rational therapeutic agents to combat infections. Noroviruses are nonenveloped, icosahedral viruses of global importance to human health. They are a common cause of acute gastroenteritis, yet no vaccines or specific antiviral agents are available. Here, we use genetics and cryo-electron microscopy (cryo-EM) to study the high-resolution solution structures of murine norovirus as a model for human viruses. By comparing our 3 structures (at 2.9- to 3.1-Å resolution), we show that whilst there is little change to the shell domain of the capsid, the radiating protruding domains are flexible, adopting distinct states both independently and synchronously. In doing so, the capsids sample a range of conformational space, with implications for maintaining virion stability and infectivity.
Collapse
|
9
|
Katayama K. [Review Norovirus]. Uirusu 2020; 70:117-128. [PMID: 34544926 DOI: 10.2222/jsv.70.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Noroviruses commonly cause infectious gastroenteritis and massive food poisoning. There is an urgent need to elucidate the infection mechanism of noroviruses and to develop vaccines and therapeutic drugs. In addition to human disease, noroviruses have been implicated in animal disease. Noroviruses that cause murine diseases can be propagated in strained cultured cells, and for many years, murine norovirus has been used as a model for human noroviruses that could not be propagated in cultured cells. That model and advances in technology have been instrumental in basic studies of noroviruses. From structural biology, noroviruses undergo dynamic shape changes to improve their infectivity when they infect cells. New culture techniques have made human intestinal organoids available for studying the mechanisms of pathogenic expression of human noroviruses in the intestinal tract, mechanisms of infection growth, and the search for receptor molecules. Vaccines and antivirals using human intestinal organoids are under active development, and some are already in clinical trials. In this paper, I review the latest research results, vaccine development, and other advances from the history of norovirus discovery.
Collapse
Affiliation(s)
- Kazuhiko Katayama
- Laboratory of Viral Infection I, Department of Infection Control and Immunology, Ōmura Satoshi Memorial Institute & Graduate School of Infection Control Sciences, Kitasato University
| |
Collapse
|
10
|
Ailavadi S, Davidson PM, Morgan MT, D'Souza DH. Thermal Inactivation Kinetics of Tulane Virus in Cell-Culture Medium and Spinach. J Food Sci 2019; 84:557-563. [DOI: 10.1111/1750-3841.14461] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/25/2018] [Accepted: 01/12/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Sukriti Ailavadi
- Dept. of Food Science; Univ. of Tennessee; 2605 River Drive Knoxville TN 37996 U.S.A
| | - P. Michael Davidson
- Dept. of Food Science; Univ. of Tennessee; 2605 River Drive Knoxville TN 37996 U.S.A
| | - Mark T. Morgan
- Dept. of Food Science; Univ. of Tennessee; 2605 River Drive Knoxville TN 37996 U.S.A
| | - Doris H. D'Souza
- Dept. of Food Science; Univ. of Tennessee; 2605 River Drive Knoxville TN 37996 U.S.A
| |
Collapse
|
11
|
Li X, Huang R, Chen H. Evaluation of Assays to Quantify Infectious Human Norovirus for Heat and High-Pressure Inactivation Studies Using Tulane Virus. FOOD AND ENVIRONMENTAL VIROLOGY 2017; 9:314-325. [PMID: 28238030 DOI: 10.1007/s12560-017-9288-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
We compared the heat and high hydrostatic pressure (HHP) inactivation results of Tulane virus (TV), a human norovirus (HuNoV) surrogate, obtained by plaque assay, direct quantitative reverse transcription PCR (RT-qPCR), porcine gastric mucin magnetic beads (PGM-MBs) binding assay followed by RT-qPCR (PGM/PCR), and propidium monoazide (PMA) assay followed by RT-qPCR (PMA/PCR). Heat and HHP inactivation of a HuNoV genotype I.1 (GI.1) strain and a genotype II.4 (GII.4) strain was also evaluated using those molecular assays. Viruses were heat treated at 50-90 °C for 2 min and HHP treated at 100-550 MPa at initial temperatures of 4 or 21 °C for 2 min. For heat treatment, the three molecular methods significantly underestimated the inactivation of TV. It could be logically concluded that the PGM/PCR assay was better than the PMA/PCR and direct RT-qPCR assays in estimating the inactivation of HuNoV GI.1. The three molecular methods were comparable in estimating the heat inactivation of GII.4. For HHP treatment, both PGM/PCR and PMA/PCR assays were able to estimate inactivation of TV at ≤~2-log reduction levels, but significantly underestimated its inactivation at >~2-log reduction levels. The direct RT-qPCR assay was the worst method for estimating HHP inactivation of TV. It could be logically concluded that the PGM/PCR and PMA/PCR assays were comparable in estimating the HHP inactivation of GI.1 and both were significantly better than the direct RT-qPCR assay. Among the three molecular methods, the PGM/PCR assay was the best in estimating the HHP inactivation of GII.4. These results demonstrated that the PGM/PCR assay was probably the method of choice in estimating the inactivation of HuNoV GI.1 and GII.4 for heat and HHP treatments, but this method would likely result in underestimation of HuNoV inactivation.
Collapse
Affiliation(s)
- Xinhui Li
- Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI, 54601, USA
| | - Runze Huang
- Department of Animal & Food Sciences, University of Delaware, Newark, DE, 19716-2150, USA
| | - Haiqiang Chen
- Department of Animal & Food Sciences, University of Delaware, Newark, DE, 19716-2150, USA.
| |
Collapse
|
12
|
Yu G, Li K, Huang P, Jiang X, Jiang W. Antibody-Based Affinity Cryoelectron Microscopy at 2.6-Å Resolution. Structure 2017; 24:1984-1990. [PMID: 27806259 DOI: 10.1016/j.str.2016.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 02/02/2023]
Abstract
The affinity cryoelectron microscopy (cryo-EM) approach has been explored in recent years to simplify and/or improve the sample preparation for cryo-EM, which can bring previously challenging specimens such as those of low abundance and/or unpurified ones within reach of the cryo-EM technique. Despite the demonstrated successes for solving structures to low to intermediate resolutions, the lack of near-atomic structures using this approach has led to a common perception of affinity cryo-EM as a niche technique incapable of reaching high resolutions. Here, we report a ∼2.6-Å structure solved using the antibody-based affinity grid approach with low-concentration Tulane virus purified from a low-yield cell-culture system that has been challenging to standard cryo-EM grid preparation. Quantitative analyses of the structure indicate data and reconstruction quality comparable with the conventional grid preparation method using samples at high concentration.
Collapse
Affiliation(s)
- Guimei Yu
- Department of Biological Science, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Kunpeng Li
- Department of Biological Science, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Pengwei Huang
- Divisions of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Xi Jiang
- Divisions of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Wen Jiang
- Department of Biological Science, Markey Center for Structural Biology, Purdue University, West Lafayette, IN 47907, USA.
| |
Collapse
|
13
|
Chhabra P, Ranjan P, Cromeans T, Sambhara S, Vinjé J. Critical role of RIG-I and MDA5 in early and late stages of Tulane virus infection. J Gen Virol 2017; 98:1016-1026. [PMID: 28530548 DOI: 10.1099/jgv.0.000769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Human noroviruses are a major cause of acute gastroenteritis worldwide, but the lack of a robust cell culture system or small animal model have hampered a better understanding of innate immunity against these viruses. Tulane virus (TV) is the prototype virus of a tentative new genus, Recovirus, in the family Caliciviridae. Its epidemiology and biological properties most closely resemble human norovirus. The host innate immune response to RNA virus infection primarily involves pathogen-sensing toll-like receptors (TLRs) TLR3 and TLR7 and retinoic acid-inducible gene I-like receptor RIG-I and melanoma differentiation associated gene 5 (MDA5). In this study, by using siRNA knockdown, we report that TV infection in LLC-MK2 cells results in an early [3 h post infection (h p.i.), P<0.05] RIG-I-dependent and type I interferon-mediated antiviral response, whereas an MDA5-mediated antiviral effect was observed at later (12 h p.i.; P<0.05) stages of TV replication. Induction of RIG-I and MDA5 was critical for inhibition of TV replication. Furthermore, pre-activation of the RIG-I/MDA5 pathway prevented TV replication (>900-fold decrease; P<0.05), suggesting that RIG-I and MDA5 ligands could be used to develop novel preventive and therapeutic measures against norovirus.
Collapse
Affiliation(s)
- Preeti Chhabra
- Gastroenteritis and Respiratory Viruses Laboratory Branch, Division of Viral Diseases, National Center for Immunizations and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Priya Ranjan
- Immunology and Pathogenesis Branch, Influenza Division, National Center for Immunizations and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | | | - Suryaprakash Sambhara
- Immunology and Pathogenesis Branch, Influenza Division, National Center for Immunizations and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| | - Jan Vinjé
- Gastroenteritis and Respiratory Viruses Laboratory Branch, Division of Viral Diseases, National Center for Immunizations and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
| |
Collapse
|
14
|
Conley M, Emmott E, Orton R, Taylor D, Carneiro DG, Murata K, Goodfellow IG, Hansman GS, Bhella D. Vesivirus 2117 capsids more closely resemble sapovirus and lagovirus particles than other known vesivirus structures. J Gen Virol 2017; 98:68-76. [PMID: 27902397 PMCID: PMC5370393 DOI: 10.1099/jgv.0.000658] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/11/2016] [Indexed: 01/06/2023] Open
Abstract
Vesivirus 2117 is an adventitious agent that, in 2009, was identified as a contaminant of Chinese hamster ovary cells propagated in bioreactors at a pharmaceutical manufacturing plant belonging to Genzyme. The consequent interruption in supply of Fabrazyme and Cerezyme (drugs used to treat Fabry and Gaucher diseases, respectively) caused significant economic losses. Vesivirus 2117 is a member of the Caliciviridae, a family of small icosahedral viruses encoding a positive-sense RNA genome. We have used cryo-electron microscopy and three-dimensional image reconstruction to calculate a structure of vesivirus 2117 virus-like particles as well as feline calicivirus and a chimeric sapovirus. We present a structural comparison of several members of the Caliciviridae, showing that the distal P domain of vesivirus 2117 is morphologically distinct from that seen in other known vesivirus structures. Furthermore, at intermediate resolutions, we found a high level of structural similarity between vesivirus 2117 and Caliciviridae from other genera: sapovirus and rabbit hemorrhagic disease virus. Phylogenetic analysis confirms vesivirus 2117 as a vesivirus closely related to canine vesiviruses. We postulate that morphological differences in virion structure seen between vesivirus clades may reflect differences in receptor usage.
Collapse
Affiliation(s)
- Michaela Conley
- Medical Research Council – University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Edward Emmott
- Department of Pathology, Division of Virology, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
| | - Richard Orton
- Medical Research Council – University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - David Taylor
- National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan
- Present address: Howard Hughes Medical Institute, 742 Stanley Hall, MS 3220 University of California, Berkeley, CA 94720-3220, USA
| | - Daniel G Carneiro
- Medical Research Council – University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
- Present address: School of Immunity and Infection, Institute of Biomedical Research, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Kazuyoshi Murata
- National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Ian G Goodfellow
- Department of Pathology, Division of Virology, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
| | - Grant S Hansman
- National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan
- Present address: Centre for Infectious Diseases, Department of Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, Heidelberg 69120, Germany
| | - David Bhella
- Medical Research Council – University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, UK
| |
Collapse
|
15
|
Yu G, Li K, Liu Y, Chen Z, Wang Z, Yan R, Klose T, Tang L, Jiang W. An algorithm for estimation and correction of anisotropic magnification distortion of cryo-EM images without need of pre-calibration. J Struct Biol 2016; 195:207-215. [PMID: 27270241 DOI: 10.1016/j.jsb.2016.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/02/2016] [Accepted: 06/03/2016] [Indexed: 11/17/2022]
Abstract
Anisotropic magnification distortion of TEM images (mainly the elliptic distortion) has been recently found as a potential resolution-limiting factor in single particle 3-D reconstruction. Elliptic distortions of ∼1-3% have been reported for multiple microscopes under low magnification settings (e.g., 18,000×), which significantly limited the achievable resolution of single particle 3-D reconstruction, especially for large particles. Here we report a generic algorithm that formulates the distortion correction problem as a generalized 2-D alignment task and estimates the distortion parameters directly from the particle images. Unlike the present pre-calibration methods, our computational method is applicable to all datasets collected at a broad range of magnifications using any microscope without need of additional experimental measurements. Moreover, the per-micrograph and/or per-particle level elliptic distortion estimation in our method could resolve potential distortion variations within a cryo-EM dataset, and further improve the 3-D reconstructions relative to constant-value correction by the pre-calibration methods. With successful applications to multiple datasets and cross-validation with the pre-calibration method, we have demonstrated the validity and robustness of our algorithm in estimating the distortion; correction of the elliptic distortion significantly improved the achievable resolutions by ∼1-3 folds and enabled 3-D reconstructions of multiple viral structures at 2.4-2.6Å resolutions. The resolution limits with elliptic distortion and the amounts of resolution improvements with distortion correction were found to strongly correlate with the product of the particle size and the amount of distortion, which can help assess if elliptic distortion is a major resolution limiting factor for single particle cryo-EM projects.
Collapse
Affiliation(s)
- Guimei Yu
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Kunpeng Li
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Yue Liu
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Zhenguo Chen
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Zhiqing Wang
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Rui Yan
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Thomas Klose
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Liang Tang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA
| | - Wen Jiang
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
16
|
Yu G, Li K, Jiang W. Antibody-based affinity cryo-EM grid. Methods 2016; 100:16-24. [PMID: 26804563 DOI: 10.1016/j.ymeth.2016.01.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 12/01/2022] Open
Abstract
The Affinity Grid technique combines sample purification and cryo-Electron Microscopy (cryo-EM) grid preparation into a single step. Several types of affinity surfaces, including functionalized lipids monolayers, streptavidin 2D crystals, and covalently functionalized carbon surfaces have been reported. More recently, we presented a new affinity cryo-EM approach, cryo-SPIEM, which applies the traditional Solid Phase Immune Electron Microscopy (SPIEM) technique to cryo-EM. This approach significantly simplifies the preparation of affinity grids and directly works with native macromolecular complexes without need of target modifications. With wide availability of high affinity and high specificity antibodies, the antibody-based affinity grid would enable cryo-EM studies of the native samples directly from cell cultures, targets of low abundance, and unstable or short-lived intermediate states.
Collapse
Affiliation(s)
- Guimei Yu
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Kunpeng Li
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Wen Jiang
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
17
|
Abstract
Specific conformations of signaling proteins can serve as “signals” in signal transduction by being recognized by receptors.
Collapse
Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC)
- Brussels
- Belgium
- Vrije Universiteit Brussel
- Brussels
| |
Collapse
|
18
|
Antigenic and Cryo-Electron Microscopy Structure Analysis of a Chimeric Sapovirus Capsid. J Virol 2015; 90:2664-75. [PMID: 26699644 DOI: 10.1128/jvi.02916-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 12/18/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED The capsid protein (VP1) of all caliciviruses forms an icosahedral particle with two principal domains, shell (S) and protruding (P) domains, which are connected via a flexible hinge region. The S domain forms a scaffold surrounding the nucleic acid, while the P domains form a homodimer that interacts with receptors. The P domain is further subdivided into two subdomains, termed P1 and P2. The P2 subdomain is likely an insertion in the P1 subdomain; consequently, the P domain is divided into the P1-1, P2, and P1-2 subdomains. In order to investigate capsid antigenicity, N-terminal (N-term)/S/P1-1 and P2/P1-2 were switched between two sapovirus genotypes GI.1 and GI.5. The chimeric VP1 constructs were expressed in insect cells and were shown to self-assemble into virus-like particles (VLPs) morphologically similar to the parental VLPs. Interestingly, the chimeric VLPs had higher levels of cross-reactivities to heterogeneous antisera than the parental VLPs. In order to better understand the antigenicity from a structural perspective, we determined an intermediate-resolution (8.5-Å) cryo-electron microscopy (cryo-EM) structure of a chimeric VLP and developed a VP1 homology model. The cryo-EM structure revealed that the P domain dimers were raised slightly (∼5 Å) above the S domain. The VP1 homology model allowed us predict the S domain (67-229) and P1-1 (229-280), P2 (281-447), and P1-2 (448-567) subdomains. Our results suggested that the raised P dimers might expose immunoreactive S/P1-1 subdomain epitopes. Consequently, the higher levels of cross-reactivities with the chimeric VLPs resulted from a combination of GI.1 and GI.5 epitopes. IMPORTANCE We developed sapovirus chimeric VP1 constructs and produced the chimeric VLPs in insect cells. We found that both chimeric VLPs had a higher level of cross-reactivity against heterogeneous VLP antisera than the parental VLPs. The cryo-EM structure of one chimeric VLP (Yokote/Mc114) was solved to 8.5-Å resolution. A homology model of the VP1 indicated for the first time the putative S and P (P1-1, P2, and P1-2) domains. The overall structure of Yokote/Mc114 contained features common among other caliciviruses. We showed that the P2 subdomain was mainly involved in the homodimeric interface, whereas a large gap between the P1 subdomains had fewer interactions.
Collapse
|
19
|
Mechanism of Cell Culture Adaptation of an Enteric Calicivirus, the Porcine Sapovirus Cowden Strain. J Virol 2015; 90:1345-58. [PMID: 26581980 DOI: 10.1128/jvi.02197-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/08/2015] [Indexed: 01/21/2023] Open
Abstract
UNLABELLED The porcine sapovirus (SaV) (PoSaV) Cowden strain is one of only a few culturable enteric caliciviruses. Compared to the wild-type (WT) PoSaV Cowden strain, tissue culture-adapted (TC) PoSaV has two conserved amino acid substitutions in the RNA-dependent RNA polymerase (RdRp) and six in the capsid protein (VP1). By using the reverse-genetics system, we identified that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328), but not the substitutions in the RdRp region, were critical for the cell culture adaptation of the PoSaV Cowden strain. The other two substitutions in VP1 (residues 291 and 295) reduced virus replication in vitro. Three-dimensional (3D) structural analysis of VP1 showed that residue 178 was located near the dimer-dimer interface, which may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 were located at protruding subdomain 2 (P2) of VP1, which may influence virus binding to cellular receptors; and residue 295 was located at the interface of two monomeric VP1 proteins, which may influence VP1 dimerization. Although reversion of the mutation at residue 291 or 295 from that of the TC strain to that of the WT reduced virus replication in vitro, it enhanced virus replication in vivo, and the revertants induced higher-level serum and mucosal antibody responses than those induced by the TC PoSaV Cowden strain. Our findings reveal the molecular basis for PoSaV adaptation to cell culture. These findings may provide new, critical information for the cell culture adaptation of other PoSaV strains and human SaVs or noroviruses. IMPORTANCE The tissue culture-adapted porcine sapovirus Cowden strain is one of only a few culturable enteric caliciviruses. We discovered that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328) were critical for its adaptation to LLC-PK cells. Two substitutions in VP1 (residues 291 and 295) reduced virus replication in vitro but enhanced virus replication and induced higher-level serum and mucosal antibody responses in gnotobiotic pigs than those induced by the tissue culture-adapted strain. Structural modeling analysis of VP1 suggested that residue 178 may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 may influence virus binding to cellular receptors; and residue 295 may influence VP1 dimerization. Our findings will provide new information for the cell culture adaptation of other sapoviruses and possibly noroviruses.
Collapse
|
20
|
Tulane virus recognizes sialic acids as cellular receptors. Sci Rep 2015; 5:11784. [PMID: 26146020 PMCID: PMC4491846 DOI: 10.1038/srep11784] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/05/2015] [Indexed: 12/17/2022] Open
Abstract
The recent discovery that human noroviruses (huNoVs) recognize sialic acids (SAs) in addition to histo-blood group antigens (HBGAs) pointed to a new direction in studying virus-host interactions during calicivirus infection. HuNoVs remain difficult to study due to the lack of an effective cell culture model. In this study, we demonstrated that Tulane virus (TV), a cultivable primate calicivirus, also recognizes SAs in addition to the previously known TV-HBGA interactions. Evidence supporting this discovery includes that TV virions bound synthetic sialoglycoconjugates (SGCs) and that treatment of TV permissive LLC-MK2 cells with either neuraminidases or SA-binding lectins inhibited TV infectivity. In addition, we found that Maackia amurensis leukoagglutinin (MAL), a lectin that recognizes the α-2,3 linked SAs, bound LLC-MK2 cells, as well as TV, by which MAL promoted TV infectivity in cell culture. Our findings further highlight TV as a valuable surrogate for huNoVs, particularly in studying virus-host interactions that may involve two host carbohydrate receptors or co-receptors for infection.
Collapse
|
21
|
Abstract
UNLABELLED Tulane virus (TV), the prototype of the Recovirus genus in the calicivirus family, was isolated from the stools of rhesus monkeys and can be cultivated in vitro in monkey kidney cells. TV is genetically closely related to the genus Norovirus and recognizes the histo-blood group antigens (HBGAs), similarly to human noroviruses (NoVs), making it a valuable surrogate for human NoVs. However, the precise structures of HBGAs recognized by TV remain elusive. In this study, we performed binding and blocking experiments on TV with extended HBGA types and showed that, while TV binds all four types (types 1 to 4) of the B antigens, it recognizes only the A type 3 antigen among four types of A antigens tested. The requirements for HBGAs in TV replication were demonstrated by blocking of TV replication in cell culture using the A type 3/4 and B saliva samples. Similar results were also observed in oligosaccharide-based blocking assays. Importantly, the previously reported, unexplained increase in TV replication by oligosaccharide in cell-based blocking assays has been clarified, which will facilitate the application of TV as a surrogate for human NoVs. IMPORTANCE Our understanding of the role of HBGAs in NoV infection has been significantly advanced in the past decade, but direct evidence for HBGAs as receptors for human NoVs remains lacking due to a lack of a cell culture method. TV recognizes HBGAs and can replicate in vitro, providing a valuable surrogate for human NoVs. However, TV binds to some but not all saliva samples from A-positive individuals, and an unexplained observation of synthetic oligosaccharide blocking of TV binding has been reported. These issues have been resolved in this study.
Collapse
|
22
|
Sestak K. Role of histo-blood group antigens in primate enteric calicivirus infections. World J Virol 2014; 3:18-21. [PMID: 25392814 PMCID: PMC4227010 DOI: 10.5501/wjv.v3.i3.18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 08/20/2014] [Accepted: 09/19/2014] [Indexed: 02/05/2023] Open
Abstract
Human noroviruses (NoV) are associated with large proportion of non-bacterial diarrhea outbreaks together with > 50% of food-associated diarrheas. The function of histo-blood group antigens (HBGAs) in pathogenesis of virus infection was implicated. Until recently however, due to lack of a robust animal and in vitro models of human NoV infection, only the partial knowledge concerning the virus pathogenesis (receptor, co-receptor and target cell) and absence of viable vaccine candidates were the frequently referenced attributes of this acute diarrheal illness. Recently, a novel group of enteric caliciviruses (CV) of rhesus macaque host origin was discovered and described. The new genus within the family Caliciviridae was identified: Rhesus Enteric CV, i.e., “Recovirus” (ReCV). ReCVs are genetically and biologically close relatives of human NoVs, exhibit similar genetic and biological features and are capable of being propagated in cell culture. ReCVs cause symptomatic disease (diarrhea and fever) in experimentally inoculated macaques. Formulation and evaluation of efficient NoV vaccine might take several years. As suggested by recent studies, inhibition of HBGAs or HBGA-based antivirals could meanwhile be exploited as vaccine alternatives. The purpose of this minireview is to provide the guidance in respect to newly available primate model of enteric CV infection and its similarities with human NoV in utilizing the HBGAs as potential virus co-receptors to indirectly address the unresolved questions of NoV pathogenesis and immunity.
Collapse
|
23
|
Yu G, Vago F, Zhang D, Snyder JE, Yan R, Zhang C, Benjamin C, Jiang X, Kuhn RJ, Serwer P, Thompson DH, Jiang W. Single-step antibody-based affinity cryo-electron microscopy for imaging and structural analysis of macromolecular assemblies. J Struct Biol 2014; 187:1-9. [PMID: 24780590 DOI: 10.1016/j.jsb.2014.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 04/15/2014] [Accepted: 04/17/2014] [Indexed: 11/18/2022]
Abstract
Single particle cryo-electron microscopy (cryo-EM) is an emerging powerful tool for structural studies of macromolecular assemblies (i.e., protein complexes and viruses). Although single particle cryo-EM requires less concentrated and smaller amounts of samples than X-ray crystallography, it remains challenging to study specimens that are low-abundance, low-yield, or short-lived. The recent development of affinity grid techniques can potentially further extend single particle cryo-EM to these challenging samples by combining sample purification and cryo-EM grid preparation into a single step. Here we report a new design of affinity cryo-EM approach, cryo-SPIEM, that applies a traditional pathogen diagnosis tool Solid Phase Immune Electron Microscopy (SPIEM) to the single particle cryo-EM method. This approach provides an alternative, largely simplified and easier to use affinity grid that directly works with most native macromolecular complexes with established antibodies, and enables cryo-EM studies of native samples directly from cell cultures. In the present work, we extensively tested the feasibility of cryo-SPIEM with multiple samples including those of high or low molecular weight, macromolecules with low or high symmetry, His-tagged or native particles, and high- or low-yield macromolecules. Results for all these samples (non-purified His-tagged bacteriophage T7, His-tagged Escherichiacoli ribosomes, native Sindbis virus, and purified but low-concentration native Tulane virus) demonstrated the capability of cryo-SPIEM approach in specifically trapping and concentrating target particles on TEM grids with minimal view constraints for cryo-EM imaging and determination of 3D structures.
Collapse
Affiliation(s)
- Guimei Yu
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Frank Vago
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Dongsheng Zhang
- Divisions of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jonathan E Snyder
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Rui Yan
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Ci Zhang
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | | | - Xi Jiang
- Divisions of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Richard J Kuhn
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA
| | - Philip Serwer
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - David H Thompson
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Wen Jiang
- Markey Center for Structural Biology, Department of Biological Science, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
24
|
Abstract
With fast progresses in instrumentation, image processing algorithms, and computational resources, single particle electron cryo-microscopy (cryo-EM) 3-D reconstruction of icosahedral viruses has now reached near-atomic resolutions (3-4 Å). With comparable resolutions and more predictable outcomes, cryo-EM is now considered a preferred method over X-ray crystallography for determination of atomic structure of icosahedral viruses. At near-atomic resolutions, all-atom models or backbone models can be reliably built that allow residue level understanding of viral assembly and conformational changes among different stages of viral life cycle. With the developments of asymmetric reconstruction, it is now possible to visualize the complete structure of a complex virus with not only its icosahedral shell but also its multiple non-icosahedral structural features. In this chapter, we will describe single particle cryo-EM experimental and computational procedures for both near-atomic resolution reconstruction of icosahedral viruses and asymmetric reconstruction of viruses with both icosahedral and non-icosahedral structure components. Procedures for rigorous validation of the reconstructions and resolution evaluations using truly independent de novo initial models and refinements are also introduced.
Collapse
Affiliation(s)
- Fei Guo
- Department of Biological Sciences, Markey Center for Structural Biology, Purdue University, West Lafayette, IN, USA
| | | |
Collapse
|
25
|
Kucukelbir A, Sigworth FJ, Tagare HD. Quantifying the local resolution of cryo-EM density maps. Nat Methods 2014; 11:63-5. [PMID: 24213166 PMCID: PMC3903095 DOI: 10.1038/nmeth.2727] [Citation(s) in RCA: 1373] [Impact Index Per Article: 137.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 10/02/2013] [Indexed: 01/11/2023]
Abstract
We propose a definition of local resolution for three-dimensional electron cryo-microscopy (cryo-EM) density maps that uses local sinusoidal features. Our algorithm has no free parameters and is applicable to other imaging modalities, including tomography. By evaluating the local resolution of single-particle reconstructions and subtomogram averages for four example data sets, we report variable resolution across a 4- to 40-Å range.
Collapse
Affiliation(s)
- Alp Kucukelbir
- Department of Biomedical Engineering, Yale University, New Haven, United States
| | - Fred J. Sigworth
- Department of Biomedical Engineering, Yale University, New Haven, United States
- Department of Cellular and Molecular Physiology, Yale University, New Haven, United States
| | - Hemant D. Tagare
- Department of Biomedical Engineering, Yale University, New Haven, United States
- Department of Diagnostic Radiology, Yale University, New Haven, United States
| |
Collapse
|