RESUMO
Elicitation of broadly neutralizing antibodies (bnAbs) is a goal of vaccine design as a strategy for targeting highly divergent strains of HIV-1. Current HIV-1 vaccine design efforts seek to elicit bnAbs by first eliciting their precursors through prime-boost regimens. This requires an understanding of the co-evolution between viruses and antibodies. Towards this goal, we have analyzed two cooperating antibodies, DH475 and DH272, which exerted pressure on the HIV population in an infected donor, called CH848, to evolve in such a way that it became sensitive to the V3-glycan supersite DH270 bnAb lineage. We obtained a 2.90Å crystal structure of DH475 in complex with the Man9 glycan and a negative stain EM model of DH272 in complex with the HIV-1 spike trimer, Env. Coupled with additional modeling studies and biochemical data, our studies reveal that DH475 contacts a V3- and V4-glycan dependent epitope accessible on an open or shed Env and that DH272 makes critical contacts with the V1V2 and V3 loops on HIV-1 Env. Using these data, we suggest a prime-boost regimen that may facilitate the initiation of DH270-like bnAb precursors.
Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Vacinas , Anticorpos Neutralizantes , Anticorpos Amplamente Neutralizantes , Epitopos , Anticorpos Anti-HIV , Humanos , PolissacarídeosRESUMO
Antibodies that can neutralize diverse HIV-1 strains develop in ~10-20% of HIV-1 infected individuals, and their elicitation is a goal of vaccine design. Such antibodies can also serve as therapeutics for those who have already been infected with the virus. Structural characterizations of broadly reactive antibodies in complex with the HIV-1 spike indicate that there are a limited number of sites of vulnerability on the spike. Analysis of their structures can help reveal commonalities that would be useful in vaccine design and provide insights on combinations of antibodies that can be used to minimize the incidence of viral resistance mutations. In this review, we give an update on recent structures determined of the spike in complex with broadly neutralizing antibodies in the context of all epitopes on the HIV-1 spike identified to date.
Assuntos
Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Antígenos CD4/química , Antígenos CD4/imunologia , Epitopos/genética , Anticorpos Anti-HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Humanos , Camundongos , Mutação , Internalização do Vírus , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Coronavirus research has gained tremendous attention because of the COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus (nCoV or SARS-CoV-2). In this review, we highlight recent studies that provide atomic-resolution structural details important for the development of monoclonal antibodies (mAbs) that can be used therapeutically and prophylactically and for vaccines against SARS-CoV-2. Structural studies with SARS-CoV-2 neutralizing mAbs have revealed a diverse set of binding modes on the spike's receptor-binding domain and N-terminal domain and highlight alternative targets on the spike. We consider this structural work together with mAb effects in vivo to suggest correlations between structure and clinical applications. We also place mAbs against severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses in the context of the SARS-CoV-2 spike to suggest features that may be desirable to design mAbs or vaccines capable of conferring broad protection.