RESUMO
The isolation of CCoV-HuPn-2018 from a child respiratory swab indicates that more coronaviruses are spilling over to humans than previously appreciated. We determined the structures of the CCoV-HuPn-2018 spike glycoprotein trimer in two distinct conformational states and showed that its domain 0 recognizes sialosides. We identified that the CCoV-HuPn-2018 spike binds canine, feline, and porcine aminopeptidase N (APN) orthologs, which serve as entry receptors, and determined the structure of the receptor-binding B domain in complex with canine APN. The introduction of an oligosaccharide at position N739 of human APN renders cells susceptible to CCoV-HuPn-2018 spike-mediated entry, suggesting that single-nucleotide polymorphisms might account for viral detection in some individuals. Human polyclonal plasma antibodies elicited by HCoV-229E infection and a porcine coronavirus monoclonal antibody inhibit CCoV-HuPn-2018 spike-mediated entry, underscoring the cross-neutralizing activity among É-coronaviruses. These data pave the way for vaccine and therapeutic development targeting this zoonotic pathogen representing the eighth human-infecting coronavirus.
Assuntos
Coronavirus Humano 229E , Infecções por Coronavirus , Coronavirus , Animais , Antígenos CD13/química , Antígenos CD13/metabolismo , Gatos , Linhagem Celular , Coronavirus/metabolismo , Coronavirus Humano 229E/metabolismo , Cães , Humanos , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , SuínosRESUMO
Exposure histories to SARS-CoV-2 variants and vaccinations will shape the specificity of antibody responses. To understand the specificity of Delta-elicited antibody immunity, we characterize the polyclonal antibody response elicited by primary or mRNA vaccine-breakthrough Delta infections. Both types of infection elicit a neutralizing antibody response focused heavily on the receptor-binding domain (RBD). We use deep mutational scanning to show that mutations to the RBD's class 1 and class 2 epitopes, including sites 417, 478, and 484-486 often reduce binding of these Delta-elicited antibodies. The anti-Delta antibody response is more similar to that elicited by early 2020 viruses than the Beta variant, with mutations to the class 1 and 2, but not class 3 epitopes, having the largest effects on polyclonal antibody binding. In addition, mutations to the class 1 epitope (e.g., K417N) tend to have larger effects on antibody binding and neutralization in the Delta spike than in the D614G spike, both for vaccine- and Delta-infection-elicited antibodies. These results help elucidate how the antigenic impacts of SARS-CoV-2 mutations depend on exposure history.
Assuntos
COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Formação de Anticorpos , Epitopos , Humanos , Testes de Neutralização , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas Sintéticas , Vacinas de mRNARESUMO
Many SARS-CoV-2 variants have mutations at key sites targeted by antibodies. However, it is unknown if antibodies elicited by infection with these variants target the same or different regions of the viral spike as antibodies elicited by earlier viral isolates. Here we compare the specificities of polyclonal antibodies produced by humans infected with early 2020 isolates versus the B.1.351 variant of concern (also known as Beta or 20H/501Y.V2), which contains mutations in multiple key spike epitopes. The serum neutralizing activity of antibodies elicited by infection with both early 2020 viruses and B.1.351 is heavily focused on the spike receptor-binding domain (RBD). However, within the RBD, B.1.351-elicited antibodies are more focused on the "class 3" epitope spanning sites 443 to 452, and neutralization by these antibodies is notably less affected by mutations at residue 484. Our results show that SARS-CoV-2 variants can elicit polyclonal antibodies with different immunodominance hierarchies.
Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/imunologia , Epitopos/imunologia , Humanos , Imunização Passiva/métodos , Testes de Neutralização , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Tratamento Farmacológico da COVID-19RESUMO
There is intense interest in antibody immunity to coronaviruses. However, it is unknown if coronaviruses evolve to escape such immunity, and if so, how rapidly. Here we address this question by characterizing the historical evolution of human coronavirus 229E. We identify human sera from the 1980s and 1990s that have neutralizing titers against contemporaneous 229E that are comparable to the anti-SARS-CoV-2 titers induced by SARS-CoV-2 infection or vaccination. We test these sera against 229E strains isolated after sera collection, and find that neutralizing titers are lower against these "future" viruses. In some cases, sera that neutralize contemporaneous 229E viral strains with titers >1:100 do not detectably neutralize strains isolated 8-17 years later. The decreased neutralization of "future" viruses is due to antigenic evolution of the viral spike, especially in the receptor-binding domain. If these results extrapolate to other coronaviruses, then it may be advisable to periodically update SARS-CoV-2 vaccines.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Coronavirus Humano 229E/genética , Coronavirus Humano 229E/imunologia , Evasão da Resposta Imune , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologiaRESUMO
Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population and how this heterogeneity affects virus evolution. Here, we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of two H3N2 strains, A/Hong Kong/45/2019 and A/Perth/16/2009, affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that were fixed in influenza variants after 2020 cause greater escape from sera from younger individuals compared with adults. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups and suggest approaches to understand how this heterogeneous selection shapes viral evolution.
Assuntos
Anticorpos Antivirais , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A Subtipo H3N2 , Influenza Humana , Mutação , Humanos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Adulto , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Influenza Humana/virologia , Influenza Humana/imunologia , Fatores Etários , Pessoa de Meia-Idade , Adulto Jovem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Antígenos Virais/genética , Antígenos Virais/imunologia , Adolescente , Evolução Molecular , Idoso , CriançaRESUMO
Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population, and how this heterogeneity affects virus evolution. Here we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of the A/Hong Kong/45/2019 (H3N2) and A/Perth/16/2009 (H3N2) strains affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that fixed in influenza variants after 2020 cause the greatest escape from sera from younger individuals. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups, and suggest approaches to understand how this heterogeneous selection shapes viral evolution.
RESUMO
Exposure histories to SARS-CoV-2 variants and vaccinations will shape the specificity of antibody responses. To understand the specificity of Delta-elicited antibody immunity, we characterize the polyclonal antibody response elicited by primary or mRNA vaccine-breakthrough Delta infections. Both types of infection elicit a neutralizing antibody response focused heavily on the receptor-binding domain (RBD). We use deep mutational scanning to show that mutations to the RBD's class 1 and class 2 epitopes, including sites 417, 478, and 484-486 often reduce binding of these Delta-elicited antibodies. The anti-Delta antibody response is more similar to that elicited by early 2020 viruses than the Beta variant, with mutations to the class 1 and 2, but not class 3 epitopes, having the largest effects on polyclonal antibody binding. In addition, mutations to the class 1 epitope (e.g., K417N) tend to have larger effects on antibody binding and neutralization in the Delta spike than in the D614G spike, both for vaccine- and Delta-infection-elicited antibodies. These results help elucidate how the antigenic impacts of SARS-CoV-2 mutations depend on exposure history.
RESUMO
Antivirals are used not only in the current treatment of influenza but are also stockpiled as a first line of defense against novel influenza strains for which vaccines have yet to be developed. Identifying drug resistance mutations can guide the clinical deployment of the antiviral and can additionally define the mechanisms of drug action and drug resistance. Pimodivir is a first-in-class inhibitor of the polymerase basic protein 2 (PB2) subunit of the influenza A virus polymerase complex. A number of resistance mutations have previously been identified in treated patients or cell culture. Here, we generate a complete map of the effect of all single-amino-acid mutations to an avian PB2 on resistance to pimodivir. We identified both known and novel resistance mutations not only in the previously implicated cap-binding and mid-link domains, but also in the N-terminal domain. Our complete map of pimodivir resistance thus enables the evaluation of whether new viral strains contain mutations that will confer pimodivir resistance.
Assuntos
Antivirais/farmacologia , Aves/virologia , Farmacorresistência Viral/genética , Vírus da Influenza A/genética , Mutação , Piridinas/farmacologia , Pirimidinas/farmacologia , Pirróis/farmacologia , Proteínas Virais/genética , Células A549 , Animais , Variação Genética , Humanos , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Proteínas de Ligação ao Cap de RNA/antagonistas & inibidores , Proteínas Virais/químicaRESUMO
Many SARS-CoV-2 variants have mutations at key sites targeted by antibodies. However, it is unknown if antibodies elicited by infection with these variants target the same or different regions of the viral spike as antibodies elicited by earlier viral isolates. Here we compare the specificities of polyclonal antibodies produced by humans infected with early 2020 isolates versus the B.1.351 variant of concern (also known as Beta or 20H/501Y.V2), which contains mutations in multiple key spike epitopes. The serum neutralizing activity of antibodies elicited by infection with both early 2020 viruses and B.1.351 is heavily focused on the spike receptor-binding domain (RBD). However, within the RBD, B.1.351-elicited antibodies are more focused on the "class 3" epitope spanning sites 443 to 452, and neutralization by these antibodies is notably less affected by mutations at residue 484. Our results show that SARS-CoV-2 variants can elicit polyclonal antibodies with different immunodominance hierarchies.