A proof of concept for structure-based vaccine design targeting RSV in humans

Crank, Michelle C.; Ruckwardt, Tracy J.; Chen, Man; Morabito, Kaitlyn M.; Phung, Emily; Costner, Pamela; Holman, LaSonji A.; Hickman, Somia P.; Berkowitz, Nina M.; Gordon, Ingelise J.; Yamshchikov, Galina V.; Gaudinski, Martin R.; Kumar, Abhinav; Chang, Lauren; Moin, Syed M.; Hill, Juliane P; DiPiazza, Anthony; Schwartz, Richard; Kueltzo, Lisa A.; Cooper, Jonathan W.; Chen, Peifeng; Stein, Judith A.; Carlton, Kevin; Gall, Jason; Nason, Martha; Kwong, Peter D.; Chen, Grace L.; Mascola, John R.; McLellan, Jason S.; Ledgerwood, Julie E.; Graham, Barney S.; Team, Vrc Study

doi:10.1126/science.aav9033

Cited by 221 publications

(169 citation statements)

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“…A stabilized prefusion conformation of class I fusion proteins is desirable for vaccine 40 development because this conformation is found on infectious virions and displays most or all of 41 the neutralizing epitopes that can be targeted by antibodies to prevent the entry process [14][15][16] . We 42 and others have observed that prefusion stabilization tends to increase the recombinant 43 expression of viral glycoproteins, possibly by preventing triggering or misfolding that results 44 from a tendency to adopt the more stable postfusion structure.…”

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confidence: 99%

Structure-based Design of Prefusion-stabilized SARS-CoV-2 Spikes

Hsieh

Goldsmith

Schaub

et al. 2020

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1The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has led to accelerated 2 efforts to develop therapeutics, diagnostics, and vaccines to mitigate this public health 3 emergency. A key target of these efforts is the spike (S) protein, a large trimeric class I fusion 4 protein that is metastable and difficult to produce recombinantly in large quantities. Here, we 5 designed and expressed over 100 structure-guided spike variants based upon a previously 6 determined cryo-EM structure of the prefusion SARS-CoV-2 spike. Biochemical, biophysical 7 and structural characterization of these variants identified numerous individual substitutions that 8 increased protein yields and stability. The best variant, HexaPro, has six beneficial proline 9 substitutions leading to ~10-fold higher expression than its parental construct and is able to 10 withstand heat stress, storage at room temperature, and multiple freeze-thaws. A 3.2 Å-resolution 11 cryo-EM structure of HexaPro confirmed that it retains the prefusion spike conformation. High-12 yield production of a stabilized prefusion spike protein will accelerate the development of 13 vaccines and serological diagnostics for SARS-CoV-2. 14 3 INTRODUCTION 15 Coronaviruses are enveloped viruses containing positive-sense RNA genomes. Four human 16 coronaviruses generally cause mild respiratory illness and circulate annually. However, SARS-17 CoV and MERS-CoV were acquired by humans via zoonotic transmission and caused outbreaks 18 of severe respiratory infections with high case-fatality rates in 2002 and 2012, respectively 1,2 . 19 SARS-CoV-2 is a novel betacoronavirus that emerged in Wuhan, China in December 2019 and 20 is the causative agent of the ongoing COVID-19 pandemic 3,4 . As of May 26, 2020, the WHO has 21 reported over 5 million cases and 350,000 deaths worldwide. Effective vaccines, therapeutic 22 antibodies and small-molecule inhibitors are urgently needed, and the development of these 23 interventions is proceeding rapidly. 24 Coronavirus virions are decorated with a spike (S) glycoprotein that binds to host-cell 25 receptors and mediates cell entry via fusion of the host and viral membranes 5 . S proteins are 26 trimeric class I fusion proteins that are expressed as a single polypeptide that is subsequently 27cleaved into S1 and S2 subunits by cellular proteases 6,7 . The S1 subunit contains the receptor-28 binding domain (RBD), which, in the case of SARS-CoV-2, recognizes the angiotensin-29 converting enzyme 2 (ACE2) receptor on the host-cell surface [8][9][10] . The S2 subunit mediates 30 membrane fusion and contains an additional protease cleavage site, referred to as S2′, that is 31 adjacent to a hydrophobic fusion peptide. Binding of the RBD to ACE2 triggers S1 dissociation, 32 allowing for a large rearrangement of S2 as it transitions from a metastable prefusion 33 conformation to a highly stable postfusion conformation 6,11 . During this rearrangement, the 34 fusion peptide is inserted into the host-cell membrane after cleavage at S2′, and two h...

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mentioning

confidence: 99%

Structure-based Design of Prefusion-stabilized SARS-CoV-2 Spikes

Hsieh

Goldsmith

Schaub

et al. 2020

Preprint

Self Cite

186

294

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“…Protein-based subunit vaccines are generally safer than vaccines based on live attenuated or inactivated viruses but usually have low immunogenicity and efficacy [20,21]. However, vaccine performance can be improved by structure-based designs via masking non-neutralizing or unfavorable epitopes, or via antigen conjugation [27,38,39]. In addition, the choice of adjuvant can greatly influence the immunogenicity and efficacy of vaccines, including subunit vaccines [29,40,41].…”

Section: Discussionmentioning

confidence: 99%

Effects of Adjuvants on the Immunogenicity and Efficacy of a Zika Virus Envelope Domain III Subunit Vaccine

et al. 2019

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Zika virus (ZIKV), a mosquito-borne flavivirus, has attracted global attention due to its close association with congenital Zika syndrome and neurological diseases, and transmission through additional routes, such as sexual contact. Currently there are no vaccines approved for ZIKV, and thus, there is an urgent need to develop an effective and safe ZIKV vaccine. Domain III (DIII) of the ZIKV envelope (E) protein is an important vaccine target, and a vaccine developed using a mutant DIII of E (EDIII) protein protects adult and pregnant mice, and unborn offspring, against ZIKV infection. Here, we have used immunocompetent BALB/c mice treated with anti-interferon-α/β receptor 1 (Ifnar1) antibodies to investigate whether three adjuvants (aluminum (Alum), monophosphoryl lipid A (MPL), and MF59), either alone or in combination, could improve the efficacy of this EDIII subunit vaccine. Our data show that, although vaccine formulated with a single adjuvant induced a specific antibody and cellular immune response, and reduced viral load in mice challenged with ZIKV, the combination of Alum and MPL adjuvants led to a more robust and balanced immune response, stronger neutralizing activity against three recent ZIKV human strains, and greater protection against a high-dose ZIKV challenge. Particularly, the combination of Alum with MPL significantly reduced viral titers and viral RNA copy numbers in sera and tissues, including the male reproductive organs. Overall, this study has identified the combination of Alum and MPL as the most effective adjuvant for ZIKV EDIII subunit vaccines, and it has important implications for subunit vaccines against other enveloped viruses, including non-ZIKV flaviviruses.Vaccines 2019, 7, 161 2 of 16 with microcephaly, fetal demise, and other congenital disorders [4][5][6]. Thus, ZIKV has emerged as a global health threat and there is an urgent requirement for an effective vaccine to combat ZIKV-associated diseases.The ZIKV genome encodes a single polyprotein, which is processed into three structural proteins (capsid (C), precursor of membrane/membrane (prM/M), and envelope (E)) and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) [7][8][9]. The E protein has important roles in infection and pathogenesis, is involved in virus binding to target cells and membrane fusion, and also serves as an important vaccine target [7,8]. The E protein is a transmembrane protein and consists of three domains termed I, II, and III (DI-DIII), a fusion loop (FL), and a stalk region (S) [8]. The DI-DII region of ZIKV E protein is a target for cross-reactive antibodies with other flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), whereas the DIII domain induces ZIKV-specific antibodies [10][11][12], and therefore, is a key target for ZIKV vaccine development. ZIKV vaccine candidates under development include inactivated virus, live attenuated virus, DNA, mRNA, viral vectors, virus-like particles (VLPs), and viral proteins (or subunit vaccines) [13][14][15][16]. Although ma...

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“…Antibodies directed to antigenic sites present in the pre-F conformation are more efficient at neutralizing RSV than those directed to antigenic sites present in the more stable post-F confirmation. Although it contains a central conserved domain available for neutralizing antibody binding, the G-protein is not a primary target for vaccine development because it is mostly covered in glycans, and it is not as well conserved within RSV types as the F-protein [39,40]. F -determines viral entry to host cells G -determines binding to host cells F and G proteins have the antigenic determinants that elicit neutralizing antibodies to RSV…”

Section: The Structure Of Rsv and Immunitymentioning

confidence: 99%