I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Diamond Proposal Number(s):
[23459]
Open Access
Abstract: There is an urgent need for improved malaria vaccine immunogens. Invasion of erythrocytes by Plasmodium falciparum is essential for its life cycle, preceding symptoms of disease and parasite transmission. Antibodies which target PfRH5 are highly effective at preventing erythrocyte invasion and the most potent growth-inhibitory antibodies bind a single epitope. Here we use structure-guided approaches to design a small synthetic immunogen, RH5-34EM which recapitulates this epitope. Structural biology and biophysics demonstrate that RH5-34EM is correctly folded and binds neutralising monoclonal antibodies with nanomolar affinity. In immunised rats, RH5-34EM induces PfRH5-targeting antibodies that inhibit parasite growth. While PfRH5-specific antibodies were induced at a lower concentration by RH5-34EM than by PfRH5, RH5-34EM induced antibodies that were a thousand-fold more growth-inhibitory as a factor of PfRH5-specific antibody concentration. Finally, we show that priming with RH5-34EM and boosting with PfRH5 achieves the best balance between antibody quality and quantity and induces the most effective growth-inhibitory response. This rationally designed vaccine immunogen is now available for use as part of future malaria vaccines, alone or in combination with other immunogens.
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Sep 2024
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I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Lawrence T.
Wang
,
Andrew J. R.
Cooper
,
Brendan
Farrell
,
Kazutoyo
Miura
,
Ababacar
Diouf
,
Nicole
Müller-Sienerth
,
Cécile
Crosnier
,
Lauren
Purser
,
Payton J.
Kirtley
,
Maciej
Maciuszek
,
Jordan R.
Barrett
,
Kirsty
Mchugh
,
Rodney
Ogwang
,
Courtney
Tucker
,
Shanping
Li
,
Safiatou
Doumbo
,
Didier
Doumtabe
,
Chul-Woo
Pyo
,
Jeff
Skinner
,
Carolyn M.
Nielsen
,
Sarah E.
Silk
,
Kassoum
Kayentao
,
Aissata
Ongoiba
,
Ming
Zhao
,
Doan C.
Nguyen
,
F. Eun-Hyung
Lee
,
Angela M.
Minassian
,
Daniel E.
Geraghty
,
Boubacar
Traore
,
Robert A.
Seder
,
Brandon K.
Wilder
,
Peter D.
Crompton
,
Gavin J.
Wright
,
Carole A.
Long
,
Simon J.
Draper
,
Matthew K.
Higgins
,
Joshua
Tan
Open Access
Abstract: Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is the most advanced blood-stage malaria vaccine candidate and is being evaluated for efficacy in endemic regions, emphasizing the need to study the underlying antibody response to RH5 during natural infection, which could augment or counteract responses to vaccination. Here, we found that RH5-reactive B cells were rare, and circulating immunoglobulin G (IgG) responses to RH5 were short-lived in malaria-exposed Malian individuals, despite repeated infections over multiple years. RH5-specific monoclonal antibodies isolated from eight malaria-exposed individuals mostly targeted non-neutralizing epitopes, in contrast to antibodies isolated from five RH5-vaccinated, malaria-naive UK individuals. However, MAD8–151 and MAD8–502, isolated from two malaria-exposed Malian individuals, were among the most potent neutralizers out of 186 antibodies from both cohorts and targeted the same epitopes as the most potent vaccine-induced antibodies. These results suggest that natural malaria infection may boost RH5-vaccine-induced responses and provide a clear strategy for the development of next-generation RH5 vaccines.
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Jul 2024
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Jordan R.
Barrett
,
Dimitra
Pipini
,
Nathan D.
Wright
,
Andrew J. R.
Cooper
,
Giacomo
Gorini
,
Doris
Quinkert
,
Amelia M.
Lias
,
Hannah
Davies
,
Cassandra A.
Rigby
,
Maya
Aleshnick
,
Barnabas G.
Williams
,
William J.
Bradshaw
,
Neil G.
Paterson
,
Thomas
Martinson
,
Payton
Kirtley
,
Luc
Picard
,
Christine D.
Wiggins
,
Francesca R.
Donnellan
,
Lloyd D. W.
King
,
Lawrence T.
Wang
,
Jonathan F.
Popplewell
,
Sarah E.
Silk
,
Jed
De Ruiter Swain
,
Katherine
Skinner
,
Vinayaka
Kotraiah
,
Amy R.
Noe
,
Randall S.
Macgill
,
C. Richter
King
,
Ashley J.
Birkett
,
Lorraine A.
Soisson
,
Angela M.
Minassian
,
Douglas A.
Lauffenburger
,
Kazutoyo
Miura
,
Carole A.
Long
,
Brandon K.
Wilder
,
Lizbe
Koekemoer
,
Joshua
Tan
,
Carolyn M.
Nielsen
,
Kirsty
Mchugh
,
Simon J.
Draper
Diamond Proposal Number(s):
[28172]
Open Access
Abstract: The highly conserved and essential Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) has emerged as the leading target for vaccines against the disease-causing blood stage of malaria. However, the features of the human vaccine-induced antibody response that confer highly potent inhibition of malaria parasite invasion into red blood cells are not well defined. Here, we characterize 236 human IgG monoclonal antibodies, derived from 15 donors, induced by the most advanced PfRH5 vaccine. We define the antigenic landscape of this molecule and establish that epitope specificity, antibody association rate, and intra-PfRH5 antibody interactions are key determinants of functional anti-parasitic potency. In addition, we identify a germline IgG gene combination that results in an exceptionally potent class of antibody and demonstrate its prophylactic potential to protect against P. falciparum parasite challenge in vivo. This comprehensive dataset provides a framework to guide rational design of next-generation vaccines and prophylactic antibodies to protect against blood-stage malaria.
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Jul 2024
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
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Robert J.
Ragotte
,
David
Pulido
,
Amelia M.
Lias
,
Doris
Quinkert
,
Daniel G. W.
Alanine
,
Abhishek
Jamwal
,
Hannah
Davies
,
Adéla
Nacer
,
Edward D.
Lowe
,
Geoffrey W.
Grime
,
Joseph J.
Illingworth
,
Robert F.
Donat
,
Elspeth F.
Garman
,
Paul W.
Bowyer
,
Matthew K.
Higgins
,
Simon J.
Draper
Diamond Proposal Number(s):
[12346, 18069, 23459]
Open Access
Abstract: Understanding mechanisms of antibody synergy is important for vaccine design and antibody cocktail development. Examples of synergy between antibodies are well-documented, but the mechanisms underlying these relationships often remain poorly understood. The leading blood-stage malaria vaccine candidate, CyRPA, is essential for invasion of Plasmodium falciparum into human erythrocytes. Here we present a panel of anti-CyRPA monoclonal antibodies that strongly inhibit parasite growth in in vitro assays. Structural studies show that growth-inhibitory antibodies bind epitopes on a single face of CyRPA. We also show that pairs of non-competing inhibitory antibodies have strongly synergistic growth-inhibitory activity. These antibodies bind to neighbouring epitopes on CyRPA and form lateral, heterotypic interactions which slow antibody dissociation. We predict that such heterotypic interactions will be a feature of many immune responses. Immunogens which elicit such synergistic antibody mixtures could increase the potency of vaccine-elicited responses to provide robust and long-lived immunity against challenging disease targets.
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Feb 2022
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I03-Macromolecular Crystallography
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Ivan
Campeotto
,
Francis
Galaway
,
Shahid
Mehmood
,
Lea K.
Barfod
,
Doris
Quinkert
,
Vinayaka
Kotraiah
,
Timothy W.
Phares
,
Katherine E.
Wright
,
Ambrosius P.
Snijders
,
Simon J.
Draper
,
Matthew K.
Higgins
,
Gavin J.
Wright
Diamond Proposal Number(s):
[23459]
Open Access
Abstract: Plasmodium falciparum RH5 is a secreted parasite ligand that is essential for erythrocyte invasion through direct interaction with the host erythrocyte receptor basigin. RH5 forms a tripartite complex with two other secreted parasite proteins, CyRPA and RIPR, and is tethered to the surface of the parasite through membrane-anchored P113. Antibodies against RH5, CyRPA, and RIPR can inhibit parasite invasion, suggesting that vaccines containing these three components have the potential to prevent blood-stage malaria. To further explore the role of the P113-RH5 interaction, we selected monoclonal antibodies against P113 that were either inhibitory or noninhibitory for RH5 binding. Using a Fab fragment as a crystallization chaperone, we determined the crystal structure of the RH5 binding region of P113 and showed that it is composed of two domains with structural similarities to rhamnose-binding lectins. We identified the RH5 binding site on P113 by using a combination of hydrogen-deuterium exchange mass spectrometry and site-directed mutagenesis. We found that a monoclonal antibody to P113 that bound to this interface and inhibited the RH5-P113 interaction did not inhibit parasite blood-stage growth. These findings provide further structural information on the protein interactions of RH5 and will be helpful in guiding the development of blood-stage malaria vaccines that target RH5.
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Oct 2020
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Daniel G. W.
Alanine
,
Doris
Quinkert
,
Rasika
Kumarasingha
,
Shahid
Mehmood
,
Francesca R.
Donnellan
,
Nana K.
Minkah
,
Bernadeta
Dadonaite
,
Ababacar
Diouf
,
Francis
Galaway
,
Sarah E.
Silk
,
Abhishek
Jamwal
,
Jennifer M.
Marshall
,
Kazutoyo
Miura
,
Lander
Foquet
,
Sean C.
Elias
,
Geneviève M.
Labbé
,
Alexander D.
Douglas
,
Jing
Jin
,
Ruth O.
Payne
,
Joseph J.
Illingworth
,
David J.
Pattinson
,
David
Pulido
,
Barnabas G.
Williams
,
Willem A.
De Jongh
,
Gavin J.
Wright
,
Stefan H. I.
Kappe
,
Carol V.
Robinson
,
Carole A.
Long
,
Brendan S.
Crabb
,
Paul R.
Gilson
,
Matthew
Higgins
,
Simon J.
Draper
Diamond Proposal Number(s):
[18069]
Open Access
Abstract: The Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is the leading target for next-generation vaccines against the disease-causing blood-stage of malaria. However, little is known about how human antibodies confer functional immunity against this antigen. We isolated a panel of human monoclonal antibodies (mAbs) against PfRH5 from peripheral blood B cells from vaccinees in the first clinical trial of a PfRH5-based vaccine. We identified a subset of mAbs with neutralizing activity that bind to three distinct sites and another subset of mAbs that are non-functional, or even antagonistic to neutralizing antibodies. We also identify the epitope of a novel group of non-neutralizing antibodies that significantly reduce the speed of red blood cell invasion by the merozoite, thereby potentiating the effect of all neutralizing PfRH5 antibodies as well as synergizing with antibodies targeting other malaria invasion proteins. Our results provide a roadmap for structure-guided vaccine development to maximize antibody efficacy against blood-stage malaria.
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Jun 2019
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I03-Macromolecular Crystallography
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Thomas. A.
Rawlinson
,
Natalie M.
Barber
,
Franziska
Mohring
,
Jee Sun
Cho
,
Varakorn
Kosaisavee
,
Samuel F.
Gerard
,
Daniel G. W.
Alanine
,
Geneviève M.
Labbé
,
Sean C.
Elias
,
Sarah E.
Silk
,
Doris
Quinkert
,
Jing
Jin
,
Jennifer M.
Marshall
,
Ruth O.
Payne
,
Angela M.
Minassian
,
Bruce
Russell
,
Laurent
Rénia
,
François H.
Nosten
,
Robert W.
Moon
,
Matthew K.
Higgins
,
Simon J.
Draper
Diamond Proposal Number(s):
[18069]
Abstract: The most widespread form of malaria is caused by Plasmodium vivax. To replicate, this parasite must invade immature red blood cells through a process requiring interaction of the P. vivax Duffy binding protein (PvDBP) with its human receptor, the Duffy antigen receptor for chemokines. Naturally acquired antibodies that inhibit this interaction associate with clinical immunity, suggesting PvDBP as a leading candidate for inclusion in a vaccine to prevent malaria due to P. vivax. Here, we isolated a panel of monoclonal antibodies from human volunteers immunized in a clinical vaccine trial of PvDBP. We screened their ability to prevent PvDBP from binding to the Duffy antigen receptor for chemokines, and their capacity to block red blood cell invasion by a transgenic Plasmodium knowlesi parasite genetically modified to express PvDBP and to prevent reticulocyte invasion by multiple clinical isolates of P. vivax. This identified a broadly neutralizing human monoclonal antibody that inhibited invasion of all tested strains of P. vivax. Finally, we determined the structure of a complex of this antibody bound to PvDBP, indicating the molecular basis for inhibition. These findings will guide future vaccine design strategies and open up possibilities for testing the prophylactic use of such an antibody.
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May 2019
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Diamond Proposal Number(s):
[12346]
Open Access
Abstract: Many promising vaccine candidates from pathogenic viruses, bacteria, and parasites are unstable and cannot be produced cheaply for clinical use. For instance, Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is essential for erythrocyte invasion, is highly conserved among field isolates, and elicits antibodies that neutralize in vitro and protect in an animal model, making it a leading malaria vaccine candidate. However, functional RH5 is only expressible in eukaryotic systems and exhibits moderate temperature tolerance, limiting its usefulness in hot and low-income countries where malaria prevails. Current approaches to immunogen stabilization involve iterative application of rational or semirational design, random mutagenesis, and biochemical characterization. Typically, each round of optimization yields minor improvement in stability, and multiple rounds are required. In contrast, we developed a one-step design strategy using phylogenetic analysis and Rosetta atomistic calculations to design PfRH5 variants with improved packing and surface polarity. To demonstrate the robustness of this approach, we tested three PfRH5 designs, all of which showed improved stability relative to wild type. The best, bearing 18 mutations relative to PfRH5, expressed in a folded form in bacteria at >1 mg of protein per L of culture, and had 10–15 °C higher thermal tolerance than wild type, while also retaining ligand binding and immunogenic properties indistinguishable from wild type, proving its value as an immunogen for a future generation of vaccines against the malaria blood stage. We envision that this efficient computational stability design methodology will also be used to enhance the biophysical properties of other recalcitrant vaccine candidates from emerging pathogens.
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Jan 2017
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I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Katherine E.
Wright
,
Kathryn A.
Hjerrild
,
Jonathan
Bartlett
,
Alexander D.
Douglas
,
Jing
Jin
,
Rebecca E.
Brown
,
Joseph J.
Illingworth
,
Rebecca
Ashfield
,
Stine B.
Clemmensen
,
Willem A.
De Jongh
,
Simon J.
Draper
,
Matthew K.
Higgins
Diamond Proposal Number(s):
[9306]
Open Access
Abstract: Invasion of host erythrocytes is essential to the life cycle of Plasmodium parasites and development of the pathology of malaria. The stages of erythrocyte invasion, including initial contact, apical reorientation, junction formation, and active invagination, are directed by coordinated release of specialized apical organelles and their parasite protein contents1. Among these proteins, and central to invasion by all species, are two parasite protein families, the reticulocyte-binding protein homologue (RH) and erythrocyte-binding like proteins, which mediate host-parasite interactions2. RH5 from Plasmodium falciparum (PfRH5) is the only member of either family demonstrated to be necessary for erythrocyte invasion in all tested strains, through its interaction with the erythrocyte surface protein basigin (also known as CD147 and EMMPRIN)3, 4. Antibodies targeting PfRH5 or basigin efficiently block parasite invasion in vitro4, 5, 6, 7, 8, 9, making PfRH5 an excellent vaccine candidate. Here we present crystal structures of PfRH5 in complex with basigin and two distinct inhibitory antibodies. PfRH5 adopts a novel fold in which two three-helical bundles come together in a kite-like architecture, presenting binding sites for basigin and inhibitory antibodies at one tip. This provides the first structural insight into erythrocyte binding by the Plasmodium RH protein family and identifies novel inhibitory epitopes to guide design of a new generation of vaccines against the blood-stage parasite.
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Nov 2014
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