|
|
Danny
Axford
,
Robin
Owen
,
Jun
Aishima
,
James
Foadi
,
Ann W.
Morgan
,
James I.
Robinson
,
Joanne E.
Nettleship
,
Raymond J.
Owens
,
Isabel
Moraes
,
Elizabeth E.
Fry
,
Jonathan
Grimes
,
Karl
Harlos
,
Abhay
Kotecha
,
Jingshan
Ren
,
Geoff
Sutton
,
Thomas S.
Walter
,
David I.
Stuart
,
Gwyndaf
Evans
Open Access
Abstract: Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams.
|
Jan 2012
|
|
|
|
Open Access
Abstract: Understanding virus antigenicity is of fundamental importance for the development of better, more cross-reactive vaccines. However, as far as we are aware, no systematic work has yet been conducted using the 3D structure of a virus to identify novel epitopes. Therefore we have extended several existing structural prediction algorithms to build a method for identifying epitopes on the appropriate outer surface of intact virus capsids (which are structurally different from globular proteins in both shape and arrangement of multiple repeated elements) and applied it here as a proof of principle concept to the capsid of foot-and-mouth disease virus (FMDV). We have analysed how reliably several freely available structure-based B cell epitope prediction programs can identify already known viral epitopes of FMDV in the context of the viral capsid. To do this we constructed a simple objective metric to measure the sensitivity and discrimination of such algorithms. After optimising the parameters for five methods using an independent training set we used this measure to evaluate the methods. Individually any one algorithm performed rather poorly (three performing better than the other two) suggesting that there may be value in developing virus-specific software. Taking a very conservative approach requiring a consensus between all three top methods predicts a number of previously described antigenic residues as potential epitopes on more than one serotype of FMDV, consistent with experimental results. The consensus results identified novel residues as potential epitopes on more than one serotype. These include residues 190–192 of VP2 (not previously determined to be antigenic), residues 69–71 and 193–197 of VP3 spanning the pentamer-pentamer interface, and another region incorporating residues 83, 84 and 169–174 of VP1 (all only previously experimentally defined on serotype A). The computer programs needed to create a semi-automated procedure for carrying out this epitope prediction method are presented.
|
May 2013
|
|
|
|
Open Access
Abstract: Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) are the two major causative agents of hand, foot and mouth disease (HFMD), for which there are currently no licenced treatments. Here, the acquisition of resistance towards two novel capsid-binding compounds, NLD and ALD, was studied and compared to the analogous compound GPP3. During serial passage, EV71 rapidly became resistant to each compound and mutations at residues I113 and V123 in VP1 were identified. A mutation at residue 113 was also identified in CVA16 after passage with GPP3. The mutations were associated with reduced thermostability and were rapidly lost in the absence of inhibitors. In silico modelling suggested that the mutations prevented the compounds from binding the VP1 pocket in the capsid. Although both viruses developed resistance to these potent pocket-binding compounds, the acquired mutations were associated with large fitness costs and reverted to WT phenotype and sequence rapidly in the absence of inhibitors. The most effective inhibitor, NLD, had a very large selectivity index, showing interesting pharmacological properties as a novel anti-EV71 agent.
|
Dec 2015
|
|
|
|
Ling
Zhu
,
Xiangxi
Wang
,
Jingshan
Ren
,
Abhay
Kotecha
,
Thomas S.
Walter
,
Shuai
Yuan
,
Teruo
Yamashita
,
Tobias J.
Tuthill
,
Elizabeth E.
Fry
,
Zihe
Rao
,
David I.
Stuart
Abstract: Aichi virus (AiV), an unusual and poorly characterized picornavirus, classified in the genus Kobuvirus, can cause severe gastroenteritis and deaths in children below the age of five years, especially in developing countries1,2. The seroprevalence of AiV is approximately 60% in children under the age of ten years and reaches 90% later in life3,4. There is no available vaccine or effective antiviral treatment. Here, we describe the structure of AiV at 3.7 Å. This first high-resolution structure for a kobuvirus is intermediate between those of the enteroviruses and cardioviruses, with a shallow, narrow depression bounded by the prominent VP0 CD loops (linking the C and D strands of the β-barrel), replacing the depression known as the canyon, frequently the site of receptor attachment in enteroviruses. VP0 is not cleaved to form VP2 and VP4, so the ‘VP2’ β-barrel structure is complemented with a unique extended structure on the inside of the capsid. On the outer surface, a polyproline helix structure, not seen previously in picornaviruses is present at the C terminus of VP1, a position where integrin binding motifs are found in some other picornaviruses. A peptide corresponding to this polyproline motif somewhat attenuates virus infectivity, presumably blocking host-cell attachment. This may guide cellular receptor identification.
|
Sep 2016
|
|
|
|
Abstract: Foot-and-mouth disease virus (FMDV) is notoriously unstable, particularly the O and SAT serotypes. Consequently, vaccines derived from heat-labile SAT viruses have been linked to the induction of poor duration immunity and hence require more frequent vaccinations to ensure protection. In-silico calculations predicted residue substitutions that would increase interactions at the inter-pentameric interface supporting increased stability. We assessed the stability of the 18 recombinant mutant viruses for their growth kinetics; antigenicity; plaque morphology; genetic stability; temperature, ionic and pH stability using the thermofluor and inactivation assays, in order to evaluate potential SAT2 vaccine candidates with improved stability. The most stable mutation was the single mutant S2093Y for temperature and pH stability, whilst other promising single mutants were E3198A, L2094V,S2093H and the triple mutant F2062Y-H2087M-H3143V. Although the S2093Y mutant had the greatest stability it exhibited smaller plaques; a reduced growth rate; a change in a monoclonal antibody footprint, and poor genetic stability properties compared to the wild-type virus. However, these factors affecting production can be overcome. The addition of 1M NaCl salt was found to further increase the stability of the SAT2 panel of viruses. The S2093Y and S2093H mutants were selected for future use in stabilising SAT2 vaccines.
|
Mar 2017
|
|
|
|
Philip
Roedig
,
Helen M.
Ginn
,
Tim
Pakendorf
,
Geoff
Sutton
,
Karl
Harlos
,
Thomas S.
Walter
,
Jan
Meyer
,
Pontus
Fischer
,
Ramona
Duman
,
Ismo
Vartiainen
,
Bernd
Reime
,
Martin
Warmer
,
Aaron S.
Brewster
,
Iris D.
Young
,
Tara
Michels-Clark
,
Nicholas K.
Sauter
,
Abhay
Kotecha
,
James
Kelly
,
David J.
Rowlands
,
Marcin
Sikorsky
,
Silke
Nelson
,
Daniel S.
Damiani
,
Roberto
Alonso-Mori
,
Jingshan
Ren
,
Elizabeth E.
Fry
,
Christian
David
,
David I.
Stuart
,
Armin
Wagner
,
Alke
Meents
Abstract: We report a method for serial X-ray crystallography at X-ray free-electron lasers (XFELs), which allows for full use of the current 120-Hz repetition rate of the Linear Coherent Light Source (LCLS). Using a micropatterned silicon chip in combination with the high-speed Roadrunner goniometer for sample delivery, we were able to determine the crystal structures of the picornavirus bovine enterovirus 2 (BEV2) and the cytoplasmic polyhedrosis virus type 18 polyhedrin, with total data collection times of less than 14 and 10 min, respectively. Our method requires only micrograms of sample and should therefore broaden the applicability of serial femtosecond crystallography to challenging projects for which only limited sample amounts are available. By synchronizing the sample exchange to the XFEL repetition rate, our method allows for most efficient use of the limited beam time available at XFELs and should enable a substantial increase in sample throughput at these facilities.
|
Jun 2017
|
|
|
|
Abstract: Enterovirus 71 (EV71) is a common cause of hand, foot and mouth disease—a disease endemic especially in the Asia-Pacific region1. Scavenger receptor class B member 2 (SCARB2) is the major receptor of EV71, as well as several other enteroviruses responsible for hand, foot and mouth disease, and plays a key role in cell entry2. The isolated structures of EV71 and SCARB2 are known3,4,5,6, but how they interact to initiate infection is not. Here, we report the EV71–SCARB2 complex structure determined at 3.4 Å resolution using cryo-electron microscopy. This reveals that SCARB2 binds EV71 on the southern rim of the canyon, rather than across the canyon, as predicted3,7,8. Helices 152–163 (α5) and 183–193 (α7) of SCARB2 and the viral protein 1 (VP1) GH and VP2 EF loops of EV71 dominate the interaction, suggesting an allosteric mechanism by which receptor binding might facilitate the low-pH uncoating of the virus in the endosome/lysosome. Remarkably, many residues within the binding footprint are not conserved across SCARB2-dependent enteroviruses; however, a conserved proline and glycine seem to be key residues. Thus, although the virus maintains antigenic variability even within the receptor-binding footprint, the identification of binding ‘hot spots’ may facilitate the design of receptor mimic therapeutics less likely to quickly generate resistance.
|
Dec 2018
|
|
|
|
Gareth
Shimmon
,
Abhay
Kotecha
,
Jingshan
Ren
,
Amin S.
Asfor
,
Joseph
Newman
,
Stephen
Berryman
,
Eleanor M.
Cottam
,
Sarah
Gold
,
Toby J.
Tuthill
,
Donald P.
King
,
Emiliana
Brocchi
,
Andrew M. Q.
King
,
Ray
Owens
,
Elizabeth E.
Fry
,
David I.
Stuart
,
Alison
Burman
,
Terry
Jackson
Open Access
Abstract: Foot-and-mouth disease (FMD) affects economically important livestock and is one of the most contagious viral diseases. The most commonly used FMD diagnostic assay is a sandwich ELISA. However, the main disadvantage of this ELISA is that it requires anti-FMD virus (FMDV) serotype-specific antibodies raised in small animals. This problem can be, in part, overcome by using anti-FMDV monoclonal antibodies (MAbs) as detecting reagents. However, the long-term use of MAbs may be problematic and they may need to be replaced. Here we have constructed chimeric antibodies (mouse/rabbit D9) and Fabs (fragment antigen-binding) (mouse/cattle D9) using the Fv (fragment variable) regions of a mouse MAb, D9 (MAb D9), which recognises type O FMDV. The mouse/rabbit D9 chimeric antibody retained the FMDV serotype-specificity of MAb D9 and performed well in a FMDV detection ELISA as well as in routine laboratory assays. Cryo-electron microscopy analysis confirmed engagement with antigenic site 1 and peptide competition studies identified the aspartic acid at residue VP1 147 as a novel component of the D9 epitope. This chimeric expression approach is a simple but effective way to preserve valuable FMDV antibodies, and has the potential for unlimited generation of antibodies and antibody fragments in recombinant systems with the concomitant positive impacts on the 3Rs (Replacement, Reduction and Refinement) principles.
|
Aug 2018
|
|
|
|
Yuguang
Zhao
,
Daming
Zhou
,
Tao
Ni
,
Dimple
Karia
,
Abhay
Kotecha
,
Xiangxi
Wang
,
Zihe
Rao
,
E. Yvonne
Jones
,
Elizabeth E.
Fry
,
Jingshan
Ren
,
David I.
Stuart
Open Access
Abstract: Coxsackievirus A10 (CV-A10) is responsible for an escalating number of severe infections in children, but no prophylactics or therapeutics are currently available. KREMEN1 (KRM1) is the entry receptor for the largest receptor-group of hand-foot-and-mouth disease causing viruses, which includes CV-A10. We report here structures of CV-A10 mature virus alone and in complex with KRM1 as well as of the CV-A10 A-particle. The receptor spans the viral canyon with a large footprint on the virus surface. The footprint has some overlap with that seen for the neonatal Fc receptor complexed with enterovirus E6 but is larger and distinct from that of another enterovirus receptor SCARB2. Reduced occupancy of a particle-stabilising pocket factor in the complexed virus and the presence of both unbound and expanded virus particles suggests receptor binding initiates a cascade of conformational changes that produces expanded particles primed for viral uncoating.
|
Jan 2020
|
|
|
|
Open Access
Abstract: Global vaccination programs using live-attenuated oral and inactivated polio vaccine (OPV and IPV) have almost eradicated poliovirus (PV) but these vaccines or their production pose significant risk in a polio-free world. Recombinant PV virus-like particles (VLPs), lacking the viral genome, represent safe next-generation vaccines, however their production requires optimisation. Here we present an efficient mammalian expression strategy producing good yields of wild-type PV VLPs for all three serotypes and a thermostabilised variant for PV3. Whilst the wild-type VLPs were predominantly in the non-native C-antigenic form, the thermostabilised PV3 VLPs adopted the native D-antigenic conformation eliciting neutralising antibody titres equivalent to the current IPV and were indistinguishable from natural empty particles by cryo-electron microscopy with a similar stabilising lipidic pocket-factor in the VP1 β-barrel. This factor may not be available in alternative expression systems, which may require synthetic pocket-binding factors. VLPs equivalent to these mammalian expressed thermostabilized particles, represent safer non-infectious vaccine candidates for the post-eradication era.
|
Jan 2021
|
|
