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1.
Immunity ; 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39163866

RESUMEN

Despite decades of antibody research, it remains challenging to predict the specificity of an antibody solely based on its sequence. Two major obstacles are the lack of appropriate models and the inaccessibility of datasets for model training. In this study, we curated >5,000 influenza hemagglutinin (HA) antibodies by mining research publications and patents, which revealed many distinct sequence features between antibodies to HA head and stem domains. We then leveraged this dataset to develop a lightweight memory B cell language model (mBLM) for sequence-based antibody specificity prediction. Model explainability analysis showed that mBLM could identify key sequence features of HA stem antibodies. Additionally, by applying mBLM to HA antibodies with unknown epitopes, we discovered and experimentally validated many HA stem antibodies. Overall, this study not only advances our molecular understanding of the antibody response to the influenza virus but also provides a valuable resource for applying deep learning to antibody research.

2.
Immunity ; 56(11): 2621-2634.e6, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37967533

RESUMEN

There is growing appreciation for neuraminidase (NA) as an influenza vaccine target; however, its antigenicity remains poorly characterized. In this study, we isolated three broadly reactive N2 antibodies from the plasmablasts of a single vaccinee, including one that cross-reacts with NAs from seasonal H3N2 strains spanning five decades. Although these three antibodies have diverse germline usages, they recognize similar epitopes that are distant from the NA active site and instead involve the highly conserved underside of NA head domain. We also showed that all three antibodies confer prophylactic and therapeutic protection in vivo, due to both Fc effector functions and NA inhibition through steric hindrance. Additionally, the contribution of Fc effector functions to protection in vivo inversely correlates with viral growth inhibition activity in vitro. Overall, our findings advance the understanding of NA antibody response and provide important insights into the development of a broadly protective influenza vaccine.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Humana , Infecciones por Orthomyxoviridae , Humanos , Gripe Humana/prevención & control , Neuraminidasa , Infecciones por Orthomyxoviridae/prevención & control , Subtipo H3N2 del Virus de la Influenza A , Epítopos , Anticuerpos Antivirales , Anticuerpos Monoclonales , Vacunación , Glicoproteínas Hemaglutininas del Virus de la Influenza
3.
Proc Natl Acad Sci U S A ; 121(15): e2317222121, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38557175

RESUMEN

Antigenic drift of SARS-CoV-2 is typically defined by mutations in the N-terminal domain and receptor binding domain of spike protein. In contrast, whether antigenic drift occurs in the S2 domain remains largely elusive. Here, we perform a deep mutational scanning experiment to identify S2 mutations that affect binding of SARS-CoV-2 spike to three S2 apex public antibodies. Our results indicate that spatially diverse mutations, including D950N and Q954H, which are observed in Delta and Omicron variants, respectively, weaken the binding of spike to these antibodies. Although S2 apex antibodies are known to be nonneutralizing, we show that they confer protection in vivo through Fc-mediated effector functions. Overall, this study indicates that the S2 domain of SARS-CoV-2 spike can undergo antigenic drift, which represents a potential challenge for the development of more universal coronavirus vaccines.


Asunto(s)
Deriva y Cambio Antigénico , COVID-19 , Humanos , SARS-CoV-2/genética , Anticuerpos , Glicoproteína de la Espiga del Coronavirus/genética , Anticuerpos Antivirales
4.
Bull World Health Organ ; 99(2): 155-161, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33551509

RESUMEN

Restrictive measures imposed because of the coronavirus disease 2019 (COVID-19) pandemic have resulted in severe social, economic and health effects. Some countries have considered the use of immunity certification as a strategy to relax these measures for people who have recovered from the infection by issuing these individuals a document, commonly called an immunity passport. This document certifies them as having protective immunity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus that causes COVID-19. The World Health Organization has advised against the implementation of immunity certification at present because of uncertainty about whether long-term immunity truly exists for those who have recovered from COVID-19 and concerns over the reliability of the proposed serological test method for determining immunity. Immunity certification can only be considered if scientific thresholds for assuring immunity are met, whether based on antibodies or other criteria. However, even if immunity certification became well supported by science, it has many ethical issues in terms of different restrictions on individual liberties and its implementation process. We examine the main considerations for the ethical acceptability of immunity certification to exempt individuals from restrictive measures during the COVID-19 pandemic. As well as needing to meet robust scientific criteria, the ethical acceptability of immunity certification depends on its uses and policy objectives and the measures in place to reduce potential harms, and prevent disproportionate burdens on non-certified individuals and violation of individual liberties and rights.


Les restrictions imposées dans le cadre de la lutte contre la pandémie de maladie à coronavirus 2019 (COVID-19) ont eu de lourdes conséquences économiques, sociales et sanitaires. Certains pays ont envisagé la mise en place d'une stratégie visant à alléger ces restrictions pour les individus guéris en leur octroyant un document communément appelé «passeport d'immunité¼. Ce document atteste qu'ils ont développé une immunité protectrice contre le coronavirus 2 du syndrome respiratoire aigu sévère (SARS-CoV-2), le virus à l'origine de la COVID-19. L'Organisation mondiale de la Santé a déconseillé l'usage du certificat d'immunité pour l'instant, car l'incertitude demeure quant à l'existence réelle d'une immunité à long terme pour ceux qui se sont remis de la COVID-19. En outre, la fiabilité des tests sérologiques censés déterminer si l'individu est immunisé n'est pas avérée. Un tel certificat ne peut être instauré que si les seuils scientifiques en matière d'immunité sont respectés, qu'ils soient fondés sur les anticorps ou sur d'autres critères. Néanmoins, même si le certificat d'immunité est désormais bien accepté par la science, il s'accompagne de nombreuses questions d'ordre éthique en ce qui concerne la limitation des libertés individuelles et la mise en œuvre. Dans le présent document, nous examinons les principales considérations à prendre en compte pour garantir l'acceptabilité éthique du certificat d'immunité visant à lever les mesures de restriction pour certaines personnes durant la pandémie de COVID-19. Cette acceptabilité éthique dépend non seulement de son degré de conformité à des critères scientifiques stricts, mais aussi de son usage, des objectifs politiques ainsi que des mesures mises en place pour atténuer les préjudices potentiels et éviter d'imposer une charge disproportionnée sur les individus dépourvus de certificat, ou de bafouer les droits et libertés de tout un chacun.


Las medidas restrictivas impuestas a causa de la pandemia de la enfermedad coronavirus de 2019 (COVID-19) han tenido graves efectos sociales, económicos y sanitarios. Algunos países han considerado la posibilidad de utilizar la certificación de inmunidad como estrategia para flexibilizar dichas medidas para las personas que se han recuperado de la infección mediante la expedición a dichas personas de un documento, comúnmente denominado pasaporte de inmunidad. Este documento certifica que han desarrollado inmunidad protectora contra el coronavirus-2 del síndrome respiratorio agudo severo (SARS-CoV-2), el virus que causa la COVID-19. La Organización Mundial de la Salud ha desaconsejado la aplicación de la certificación de la inmunidad en la actualidad debido a la incertidumbre sobre si existe realmente una inmunidad a largo plazo para quienes se han recuperado de la COVID-19 y a las preocupaciones sobre la fiabilidad del método de prueba serológica propuesto para determinar la inmunidad. La certificación de la inmunidad solo puede considerarse si se cumplen los umbrales científicos para asegurar la inmunidad, ya sea que se basen en anticuerpos o en otros criterios. Sin embargo, incluso si la certificación de la inmunidad llegara a estar bien respaldada por la ciencia, tiene muchas cuestiones éticas en cuanto a las diferentes restricciones de las libertades individuales y su proceso de aplicación. Examinamos las principales consideraciones sobre la aceptabilidad ética de la certificación de la inmunidad para eximir a los individuos de las medidas restrictivas durante la pandemia de la COVID-19. Además de necesitar cumplir criterios científicos sólidos, la aceptabilidad ética de la certificación de inmunidad depende de sus usos y objetivos de política y de las medidas que se apliquen para reducir los posibles daños y evitar que se impongan cargas desproporcionadas a las personas que no cuenten con dicha certificación y se violen las libertades y derechos individuales.


Asunto(s)
Prueba Serológica para COVID-19/ética , COVID-19/diagnóstico , Certificación/ética , Pandemias , Salud Pública/ética , Humanos , Inmunidad Humoral
6.
Biotechnol Appl Biochem ; 67(6): 880-891, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33011985

RESUMEN

This paper focuses on the ethical and regulatory issues raised by gene editing. In the introduction of this paper, authors provide the background where the ethical and regulatory issues by gene editing have been raised including the scientific dimension of gene-editing techniques. In the second part of the paper, the authors focus on ethical issues in human gene editing with the start of Huang Junjiu case and He Jiankui case. Here, the authors discuss the criteria for evaluating action, general ethical issues in gene editing, and try to answer two crucial questions: is it ethically justifiable to use human embryo in ex vivo genome editing study and is it ethically justifiable to perform heritable human genome editing? In answering the second question, the authors discuss the arguments against and for heritable human genome editing, methodological problem, and the building of an ethical framework for heritable human genome editing. In the third part of the paper, the authors focus on regulatory issues in gene editing including proactionary approach versus ethically thinking ahead approach, self-regulation versus top-down regulation, transparency versus confidentiality, and education versus punishment.


Asunto(s)
Discusiones Bioéticas , Edición Génica , Genoma Humano , China , Edición Génica/ética , Edición Génica/legislación & jurisprudencia , Humanos
7.
Bioethics ; 34(2): 172-182, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31639227

RESUMEN

This article consists of four parts. In the first part it briefly describes the history of body-to-head transplantation (BHT) and the surgical plan proposed by Drs. Sergio Canavero and Ren Xiaoping on a human subject. In the second part it argues that the BHT procedure that they propose is scientifically invalid and technically infeasible so therefore would end in failure. In the third part it argues that the present conceivable procedure of BHT cannot be ethically justified because it would bring great harm to the human subject, it is uncertain who would be the possible beneficiary, and valid informed consent cannot be obtained. In the fourth part it argues that the action of performing the procedure of BHT might violate China's current criminal and civil laws. The conclusion that follows from the arguments above is that BHT should be prohibited now and also in the near future. However, this conclusion does not preclude scientists, neurosurgeons and bioethicists doing research into scientific, technical, surgical and ethical issues raised by BHT.


Asunto(s)
Investigación Biomédica/ética , Investigación Biomédica/legislación & jurisprudencia , Ética Médica , Ética en Investigación , Cabeza/cirugía , Sujetos de Investigación , Trasplante/ética , Anastomosis Quirúrgica , China , Humanos
8.
J Org Chem ; 84(6): 3624-3631, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30806513

RESUMEN

The Cu(I)- or Ag(I)-catalyzed cycloaddition between 8-ethynyladenine or guanine nucleosides and TMSN3 gave 8-(1- H-1,2,3-triazol-4-yl) nucleosides in good yields. On the other hand, reactions of 5-ethynyluracil or cytosine nucleosides with TMSN3 led to the chemoselective formation of triazoles via Cu(I)-catalyzed cycloaddition or vinyl azides via Ag(I)-catalyzed hydroazidation. These nucleosides with a minimalistic triazolyl modification showed excellent fluorescent properties with 8-(1- H-1,2,3-triazol-4-yl)-2'-deoxyadenosine (8-TrzdA), exhibiting a quantum yield of 44%. The 8-TrzdA 5'-triphosphate was incorporated into duplex DNA containing a one-nucleotide gap by DNA polymerase ß.


Asunto(s)
Fluorescencia , Nucleósidos de Purina/química , Nucleósidos de Pirimidina/química , Triazoles/química , Catálisis , Cobre/química , Estructura Molecular , Nucleósidos de Purina/síntesis química , Nucleósidos de Pirimidina/síntesis química , Plata/química
9.
Front Bioeng Biotechnol ; 12: 1428832, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39119275

RESUMEN

This paper will focus on analyzing the argument with appealing to nature against synthetic biology and provide a counter-argument against it through demonstrating the ambiguity of the concept of nature, denying the existence of a morally significant line between natural and non/unnatural, and disproving the allegations against synthetic biology raised by the argument appealing to nature. The paper consists of two parts following a brief introduction. The first part will describe the argument appealing to nature against synthetic biology, and identify the deficiencies of the argument per se, e.g., the ambiguity of the concept 'nature'; and the problems in the morally significant line between the natural and the non/unnatural. The second part will discuss the allegations to synthetic biology stemming from this argument, e.g., committing metaphysical and ethical mistakes, and doing possible harms to the environment.

10.
Nat Commun ; 15(1): 4056, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38744813

RESUMEN

The fusion peptide of SARS-CoV-2 spike protein is functionally important for membrane fusion during virus entry and is part of a broadly neutralizing epitope. However, sequence determinants at the fusion peptide and its adjacent regions for pathogenicity and antigenicity remain elusive. In this study, we perform a series of deep mutational scanning (DMS) experiments on an S2 region spanning the fusion peptide of authentic SARS-CoV-2 in different cell lines and in the presence of broadly neutralizing antibodies. We identify mutations at residue 813 of the spike protein that reduced TMPRSS2-mediated entry with decreased virulence. In addition, we show that an F823Y mutation, present in bat betacoronavirus HKU9 spike protein, confers resistance to broadly neutralizing antibodies. Our findings provide mechanistic insights into SARS-CoV-2 pathogenicity and also highlight a potential challenge in developing broadly protective S2-based coronavirus vaccines.


Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , Mutación , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Internalización del Virus , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/metabolismo , Humanos , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Anticuerpos Neutralizantes/inmunología , COVID-19/virología , COVID-19/inmunología , Animales , Anticuerpos Antivirales/inmunología , Serina Endopeptidasas/genética , Serina Endopeptidasas/inmunología , Serina Endopeptidasas/metabolismo , Chlorocebus aethiops , Células HEK293 , Células Vero , Epítopos/inmunología , Epítopos/genética , Línea Celular , Ratones
11.
bioRxiv ; 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39257766

RESUMEN

Antibody discovery is crucial for developing therapeutics and vaccines as well as understanding adaptive immunity. However, the lack of approaches to synthesize antibodies with defined sequences in a high-throughput manner represents a major bottleneck in antibody discovery. Here, we presented oPool+ display, which combines oligo pool synthesis and mRNA display to construct and characterize many natively paired antibodies in parallel. As a proof-of-concept, we applied oPool+ display to rapidly screen the binding activity of >300 natively paired influenza hemagglutinin (HA) antibodies against the conserved HA stem domain. Structural analysis of 16.ND.92, one of the identified HA stem antibodies, revealed a unique binding mode distinct from other known broadly neutralizing HA stem antibodies with convergent sequence features. Yet, despite such differences, 16.ND.92 remained broadly reactive and conferred in vivo protection. Overall, this study not only established an experimental platform that can be applied in both research and therapeutics to accelerate antibody discovery, but also provides molecular insights into antibody responses to the influenza HA stem, which is a major target for universal influenza vaccine development.

12.
Nat Commun ; 15(1): 5175, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890325

RESUMEN

The receptor-binding site of influenza A virus hemagglutinin partially overlaps with major antigenic sites and constantly evolves. In this study, we observe that mutations G186D and D190N in the hemagglutinin receptor-binding site have coevolved in two recent human H3N2 clades. X-ray crystallography results show that these mutations coordinately drive the evolution of the hemagglutinin receptor binding mode. Epistasis between G186D and D190N is further demonstrated by glycan binding and thermostability analyses. Immunization and neutralization experiments using mouse and human samples indicate that the evolution of receptor binding mode is accompanied by a change in antigenicity. Besides, combinatorial mutagenesis reveals that G186D and D190N, along with other natural mutations in recent H3N2 strains, alter the compatibility with a common egg-adaptive mutation in seasonal influenza vaccines. Overall, our findings elucidate the role of epistasis in shaping the recent evolution of human H3N2 hemagglutinin and substantiate the high evolvability of its receptor-binding mode.


Asunto(s)
Epistasis Genética , Evolución Molecular , Glicoproteínas Hemaglutininas del Virus de la Influenza , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana , Humanos , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Animales , Ratones , Sitios de Unión , Gripe Humana/virología , Mutación , Cristalografía por Rayos X , Vacunas contra la Influenza , Unión Proteica , Receptores Virales/metabolismo , Receptores Virales/genética , Receptores Virales/química , Femenino
13.
Front Pharmacol ; 14: 1214590, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37701030

RESUMEN

As international academic exchanges and cooperation deepen, China has actively engaged in international biomedical research collaboration and achieved significant success. However, these accomplishments have been accompanied by ethical controversies and issues, with ethics dumping being a recurrently discussed focus among scholars. This paper reviews ethics dumping incidents in China's biomedical research field and analyzes the underlying causes to answer why China is often susceptible to ethics dumping. We argue that the primary reasons include weak ethical awareness among some researchers, an oversimplified research evaluation system, gaps in relevant ethics governance and oversight mechanisms, and limited capabilities of certain ethics committees. To address these issues, we propose five ethics governance recommendations: establishing refined ethics committees at various levels and types; advancing theoretical and practical research on science and technology ethics governance; strengthening legislation and regulation related to emerging science and technology; emphasizing self-regulation and capacity building of research institutions; and providing special protection and healthcare for victims of ethics dumping. The aim is to enhance China's research supervision system and prevent similar ethics dumping incidents from recurring.

14.
Front Genet ; 14: 1261623, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37928244

RESUMEN

Background: Human biobanks are an essential resource for contemporary medical research, crucial in treating and preventing human diseases and improving health. Public trust in human biobanks is a vital social prerequisite for their continued operation and related research. Methods: Drawing on the "leap of faith" theory proposed by Georg Simmel and Guido Möllering, this paper first examines the relationship between public trust and human biobanks and the process through which such trust is established. Subsequently, based on the results of this analysis, targeted policy recommendations are put forward to consolidate or enhance public trust in human biobanks. Results: Public trust in human biobanks stems from certain "good reasons," through which uncertainty and vulnerability are "suspended" by faith, leading to a leap toward the "land of expectations." In this progress, the critical factors in building and enhancing public trust in human biobanks are the public's propensity to trust, the inherent trustworthiness of human biobanks, and the security and interactivity of the trust environment. Conclusion: Public trust in human biobanks cannot be determined by any universal formula, as it is influenced by many factors, including intangible elements such as faith that defy empirical understanding. Nonetheless, public trust in human biobanks can be enhanced through measures such as fostering the public's propensity to trust, enhancing the inherent trustworthiness of human biobanks, establishing structural safeguards for the trust environment through ethical norms, systems, and supervision, and promoting public participation.

15.
bioRxiv ; 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-37461670

RESUMEN

IGHV1-69 is frequently utilized by broadly neutralizing influenza antibodies to the hemagglutinin (HA) stem. These IGHV1-69 HA stem antibodies have diverse complementarity-determining region (CDR) H3 sequences. Besides, their light chains have minimal to no contact with the epitope. Consequently, sequence determinants that confer IGHV1-69 antibodies with HA stem specificity remain largely elusive. Using high-throughput experiments, this study revealed the importance of light chain sequence for the IGHV1-69 HA stem antibody CR9114, which is the broadest influenza antibody known to date. Moreover, we demonstrated that the CDR H3 sequences from many other IGHV1-69 antibodies, including those to HA stem, were incompatible with CR9114. Along with mutagenesis and structural analysis, our results indicate that light chain and CDR H3 sequences coordinately determine the HA stem specificity of IGHV1-69 antibodies. Overall, this work provides molecular insights into broadly neutralizing antibody responses to influenza virus, which have important implications for universal influenza vaccine development.

16.
Cell Rep ; 42(11): 113410, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-37976161

RESUMEN

IGHV1-69 is frequently utilized by broadly neutralizing influenza antibodies to the hemagglutinin (HA) stem. These IGHV1-69 HA stem antibodies have diverse complementarity-determining region (CDR) H3 sequences. Besides, their light chains have minimal to no contact with the epitope. Consequently, sequence determinants that confer IGHV1-69 antibodies with HA stem specificity remain largely elusive. Using high-throughput experiments, this study reveals the importance of light-chain sequence for the IGHV1-69 HA stem antibody CR9114, which is the broadest influenza antibody known to date. Moreover, we demonstrate that the CDR H3 sequences from many other IGHV1-69 antibodies, including those to the HA stem, are incompatible with CR9114. Along with mutagenesis and structural analysis, our results indicate that light-chain and CDR H3 sequences coordinately determine the HA stem specificity of IGHV1-69 antibodies. Overall, this work provides molecular insights into broadly neutralizing antibody responses to influenza virus, which have important implications for universal influenza vaccine development.


Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Humanos , Hemaglutininas , Anticuerpos ampliamente neutralizantes , Anticuerpos Neutralizantes , Glicoproteínas Hemaglutininas del Virus de la Influenza , Anticuerpos Antivirales , Regiones Determinantes de Complementariedad
17.
bioRxiv ; 2023 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-37745338

RESUMEN

Despite decades of antibody research, it remains challenging to predict the specificity of an antibody solely based on its sequence. Two major obstacles are the lack of appropriate models and inaccessibility of datasets for model training. In this study, we curated a dataset of >5,000 influenza hemagglutinin (HA) antibodies by mining research publications and patents, which revealed many distinct sequence features between antibodies to HA head and stem domains. We then leveraged this dataset to develop a lightweight memory B cell language model (mBLM) for sequence-based antibody specificity prediction. Model explainability analysis showed that mBLM captured key sequence motifs of HA stem antibodies. Additionally, by applying mBLM to HA antibodies with unknown epitopes, we discovered and experimentally validated many HA stem antibodies. Overall, this study not only advances our molecular understanding of antibody response to influenza virus, but also provides an invaluable resource for applying deep learning to antibody research.

18.
bioRxiv ; 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38076875

RESUMEN

The fusion peptide of SARS-CoV-2 spike protein is functionally important for membrane fusion during virus entry and is part of a broadly neutralizing epitope. However, sequence determinants at the fusion peptide and its adjacent regions for pathogenicity and antigenicity remain elusive. In this study, we performed a series of deep mutational scanning (DMS) experiments on an S2 region spanning the fusion peptide of authentic SARS-CoV-2 in different cell lines and in the presence of broadly neutralizing antibodies. We identified mutations at residue 813 of the spike protein that reduced TMPRSS2-mediated entry with decreased virulence. In addition, we showed that an F823Y mutation, present in bat betacoronavirus HKU9 spike protein, confers resistance to broadly neutralizing antibodies. Our findings provide mechanistic insights into SARS-CoV-2 pathogenicity and also highlight a potential challenge in developing broadly protective S2-based coronavirus vaccines.

19.
Nat Commun ; 14(1): 2003, 2023 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-37037866

RESUMEN

Designing prefusion-stabilized SARS-CoV-2 spike is critical for the effectiveness of COVID-19 vaccines. All COVID-19 vaccines in the US encode spike with K986P/V987P mutations to stabilize its prefusion conformation. However, contemporary methods on engineering prefusion-stabilized spike immunogens involve tedious experimental work and heavily rely on structural information. Here, we establish a systematic and unbiased method of identifying mutations that concomitantly improve expression and stabilize the prefusion conformation of the SARS-CoV-2 spike. Our method integrates a fluorescence-based fusion assay, mammalian cell display technology, and deep mutational scanning. As a proof-of-concept, we apply this method to a region in the S2 domain that includes the first heptad repeat and central helix. Our results reveal that besides K986P and V987P, several mutations simultaneously improve expression and significantly lower the fusogenicity of the spike. As prefusion stabilization is a common challenge for viral immunogen design, this work will help accelerate vaccine development against different viruses.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Humanos , COVID-19/prevención & control , Vacunas contra la COVID-19 , Glicoproteína de la Espiga del Coronavirus , Mutación , Mamíferos/metabolismo
20.
Cell Rep ; 42(1): 111951, 2023 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-36640354

RESUMEN

Influenza neuraminidase (NA) has received increasing attention as an effective vaccine target. However, its mutational tolerance is not well characterized. Here, the fitness effects of >6,000 mutations in human H3N2 NA are probed using deep mutational scanning. Our result shows that while its antigenic regions have high mutational tolerance, there are solvent-exposed regions with low mutational tolerance. We also find that protein stability is a major determinant of NA mutational fitness. The deep mutational scanning result correlates well with mutational fitness inferred from natural sequences using a protein language model, substantiating the relevance of our findings to the natural evolution of circulating strains. Additional analysis further suggests that human H3N2 NA is far from running out of mutations despite already evolving for >50 years. Overall, this study advances our understanding of the evolutionary potential of NA and the underlying biophysical constraints, which in turn provide insights into NA-based vaccine design.


Asunto(s)
Gripe Humana , Humanos , Gripe Humana/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Neuraminidasa/genética , Neuraminidasa/metabolismo , Evolución Molecular , Mutación/genética
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