RESUMO
Coronavirus disease 2019, caused by SARS-CoV-2, remains an on-going pandemic, partly due to the emergence of variant viruses that can "break-through" the protection of the current vaccines and neutralizing antibodies (nAbs), highlighting the needs for broadly nAbs and next-generation vaccines. We report an antibody that exhibits breadth and potency in binding the receptor-binding domain (RBD) of the virus spike glycoprotein across SARS coronaviruses. Initially, a lead antibody was computationally discovered and crystallographically validated that binds to a highly conserved surface of the RBD of wild-type SARS-CoV-2. Subsequently, through experimental affinity enhancement and computational affinity maturation, it was further developed to bind the RBD of all concerning SARS-CoV-2 variants, SARS-CoV-1 and pangolin coronavirus with pico-molar binding affinities, consistently exhibited strong neutralization activity against wild-type SARS-CoV-2 and the Alpha and Delta variants. These results identify a vulnerable target site on coronaviruses for development of pan-sarbecovirus nAbs and vaccines.
Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Antivirais/genética , Anticorpos Antivirais/metabolismo , Afinidade de Anticorpos , Especificidade de Anticorpos , Reações Antígeno-Anticorpo , Antígenos Virais/química , Antígenos Virais/genética , Anticorpos Amplamente Neutralizantes/genética , Anticorpos Amplamente Neutralizantes/metabolismo , Cristalografia por Raios X , Epitopos/química , Epitopos/imunologia , Humanos , Fragmentos de Imunoglobulinas/imunologia , Simulação de Acoplamento Molecular , Método de Monte Carlo , Testes de Neutralização , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Domínios Proteicos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/metabolismo , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
BACKGROUND: The mechanisms of immune response are structured within a highly complex regulatory system. Genetic associations with variation in the immune response to rubella vaccine have typically been assessed one locus at a time. We simultaneously assessed the associations between 726 SNPs tagging 84 candidate immune response genes and rubella-specific antibody levels. Blood samples were obtained from 714 school-aged children who had received two doses of MMR vaccine. Associations between rubella-specific antibody levels and 726 candidate tagSNPs were assessed both one SNP at a time and in a variety of multigenic analyses. RESULTS: Single-SNP assessments identified 4 SNPs that appeared to be univariately associated with rubella antibody levels: rs2844482 (p = 0.0002) and rs2857708 (p = 0.001) in the 5'UTR of the LTA gene, rs7801617 in the 5'UTR of the IL6 gene (p = 0.0005), and rs4787947 in the 5'UTR of the IL4R gene (p = 0.002). While there was not significant evidence in favor of epistatic genetic associations among the candidate SNPs, multigenic analyses identified 29 SNPs significantly associated with rubella antibody levels when selected as a group (p = 0.017). This collection of SNPs included not only those that were significant univariately, but others that would not have been identified if only considered in isolation from the other SNPs. CONCLUSIONS: For the first time, multigenic assessment of associations between candidate SNPs and rubella antibody levels identified a broad number of genetic associations that would not have been deemed important univariately. It is important to consider approaches like those applied here in order to better understand the full genetic complexity of response to vaccination.
Assuntos
Anticorpos Antivirais/biossíntese , Interleucina-6/genética , Lectinas/genética , Vacina contra Sarampo-Caxumba-Rubéola , Receptores de Interleucina-4/genética , Rubéola (Sarampo Alemão)/prevenção & controle , Adolescente , Anticorpos Antivirais/sangue , Anticorpos Antivirais/genética , Criança , Estudos de Associação Genética , Humanos , Polimorfismo de Nucleotídeo Único , População , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/genética , Rubéola (Sarampo Alemão)/imunologia , VacinaçãoRESUMO
Differentiating foot-and-mouth disease virus (FMDV) antibodies generated during a natural infection from those due to vaccination (DIVA) is crucial for proving freedom from disease after an outbreak and allowing resumption of trade in livestock products. The World Organisation for Animal Health (OIE) recommends that FMDV vaccines are composed of inactivated virus that has been purified to remove non-structural viral proteins. Such purified vaccines primarily induce antibodies to viral structural proteins, whereas replicating virus stimulates host antibodies specific for both structural and non-structural proteins. The current preferred FMDV DIVA test is a competitive ELISA (C-ELISA) designed to detect antibodies to the non-structural protein 3ABC. Previously, we described the development of an FMDV DIVA test based entirely on recombinant proteins (the recombinant detecting antibody and the 3ABC coating antigen) produced in Escherichia coli. In this study, we have determined the precise binding site of the recombinant detecting antibody to a conserved sequence within the 3B region of the 3ABC protein, replaced the original E-tag of the detecting antibody with two in-house tags and engineered a direct antibody-reporting enzyme (alkaline phosphatase) fusion protein. These modifications have further improved the DIVA test, providing great potential for large scale production and uptake due to its simplicity, reproducibility and low cost.