RESUMEN
The CD4-binding site (CD4bs) is a conserved epitope on HIV-1 envelope (Env) that can be targeted by protective broadly neutralizing antibodies (bnAbs). HIV-1 vaccines have not elicited CD4bs bnAbs for many reasons, including the occlusion of CD4bs by glycans, expansion of appropriate naive B cells with immunogens, and selection of functional antibody mutations. Here, we demonstrate that immunization of macaques with a CD4bs-targeting immunogen elicits neutralizing bnAb precursors with structural and genetic features of CD4-mimicking bnAbs. Structures of the CD4bs nAb bound to HIV-1 Env demonstrated binding angles and heavy-chain interactions characteristic of all known human CD4-mimicking bnAbs. Macaque nAb were derived from variable and joining gene segments orthologous to the genes of human VH1-46-class bnAb. This vaccine study initiated in primates the B cells from which CD4bs bnAbs can derive, accomplishing the key first step in the development of an effective HIV-1 vaccine.
Asunto(s)
Vacunas contra el SIDA , VIH-1 , Animales , Humanos , Anticuerpos ampliamente neutralizantes , Antígenos CD4 , Moléculas de Adhesión Celular , VIH-1/fisiología , Macaca , Vacunas contra el SIDA/inmunologíaRESUMEN
A critical roadblock to HIV vaccine development is the inability to induce B cell lineages of broadly neutralizing antibodies (bnAbs) in humans. In people living with HIV-1, bnAbs take years to develop. The HVTN 133 clinical trial studied a peptide/liposome immunogen targeting B cell lineages of HIV-1 envelope (Env) membrane-proximal external region (MPER) bnAbs (NCT03934541). Here, we report MPER peptide-liposome induction of polyclonal HIV-1 B cell lineages of mature bnAbs and their precursors, the most potent of which neutralized 15% of global tier 2 HIV-1 strains and 35% of clade B strains with lineage initiation after the second immunization. Neutralization was enhanced by vaccine selection of improbable mutations that increased antibody binding to gp41 and lipids. This study demonstrates proof of concept for rapid vaccine induction of human B cell lineages with heterologous neutralizing activity and selection of antibody improbable mutations and outlines a path for successful HIV-1 vaccine development.
Asunto(s)
Vacunas contra el SIDA , Anticuerpos Neutralizantes , Linfocitos B , Anticuerpos Anti-VIH , VIH-1 , Humanos , Vacunas contra el SIDA/inmunología , VIH-1/inmunología , Anticuerpos Neutralizantes/inmunología , Linfocitos B/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Linaje de la Célula , Liposomas , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Mutación , Proteína gp41 de Envoltorio del VIH/inmunologíaRESUMEN
Congenital Zika virus (ZIKV) infection results in neurodevelopmental deficits in up to 14% of infants born to ZIKV-infected mothers. Neutralizing antibodies are a critical component of protective immunity. Here, we demonstrate that plasma IgM contributes to ZIKV immunity in pregnancy, mediating neutralization up to 3 months post-symptoms. From a ZIKV-infected pregnant woman, we isolated a pentameric ZIKV-specific IgM (DH1017.IgM) that exhibited ultrapotent ZIKV neutralization dependent on the IgM isotype. DH1017.IgM targets an envelope dimer epitope within domain II. The epitope arrangement on the virion is compatible with concurrent engagement of all ten antigen-binding sites of DH1017.IgM, a solution not available to IgG. DH1017.IgM protected mice against viremia upon lethal ZIKV challenge more efficiently than when expressed as an IgG. Our findings identify a role for antibodies of the IgM isotype in protection against ZIKV and posit DH1017.IgM as a safe and effective candidate immunotherapeutic, particularly during pregnancy.
Asunto(s)
Inmunoglobulina M , Embarazo , Infección por el Virus Zika , Virus Zika , Animales , Femenino , Ratones , Embarazo/inmunología , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Epítopos , Pruebas de Neutralización , Infección por el Virus Zika/inmunología , Inmunoglobulina M/inmunología , Inmunoglobulina M/aislamiento & purificaciónRESUMEN
SARS-CoV-2-neutralizing antibodies (NAbs) protect against COVID-19. A concern regarding SARS-CoV-2 antibodies is whether they mediate disease enhancement. Here, we isolated NAbs against the receptor-binding domain (RBD) or the N-terminal domain (NTD) of SARS-CoV-2 spike from individuals with acute or convalescent SARS-CoV-2 or a history of SARS-CoV infection. Cryo-electron microscopy of RBD and NTD antibodies demonstrated function-specific modes of binding. Select RBD NAbs also demonstrated Fc receptor-γ (FcγR)-mediated enhancement of virus infection in vitro, while five non-neutralizing NTD antibodies mediated FcγR-independent in vitro infection enhancement. However, both types of infection-enhancing antibodies protected from SARS-CoV-2 replication in monkeys and mice. Three of 46 monkeys infused with enhancing antibodies had higher lung inflammation scores compared to controls. One monkey had alveolar edema and elevated bronchoalveolar lavage inflammatory cytokines. Thus, while in vitro antibody-enhanced infection does not necessarily herald enhanced infection in vivo, increased lung inflammation can rarely occur in SARS-CoV-2 antibody-infused macaques.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/inmunología , Animales , Anticuerpos Antivirales/inmunología , Líquido del Lavado Bronquioalveolar/química , COVID-19/patología , COVID-19/virología , Citocinas/metabolismo , Femenino , Haplorrinos , Humanos , Pulmón/patología , Pulmón/virología , Masculino , Ratones , Ratones Endogámicos BALB C , Dominios Proteicos , ARN Guía de Kinetoplastida/metabolismo , Receptores de IgG/metabolismo , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/química , Carga Viral , Replicación ViralRESUMEN
Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , VIH-1/inmunología , Fragmentos Fab de Inmunoglobulinas/inmunología , Polisacáridos/inmunología , SARS-CoV-2/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Linfocitos B/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , COVID-19/inmunología , Dimerización , Epítopos/inmunología , Glicosilación , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Macaca mulatta , Polisacáridos/química , Receptores de Antígenos de Linfocitos B/química , Virus de la Inmunodeficiencia de los Simios/genética , Vacunas/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Antibodies with ontogenies from VH1-2 or VH1-46-germline genes dominate the broadly neutralizing response against the CD4-binding site (CD4bs) on HIV-1. Here, we define with longitudinal sampling from time-of-infection the development of a VH1-46-derived antibody lineage that matured to neutralize 90% of HIV-1 isolates. Structures of lineage antibodies CH235 (week 41 from time-of-infection, 18% breadth), CH235.9 (week 152, 77%), and CH235.12 (week 323, 90%) demonstrated the maturing epitope to focus on the conformationally invariant portion of the CD4bs. Similarities between CH235 lineage and five unrelated CD4bs lineages in epitope focusing, length-of-time to develop breadth, and extraordinary level of somatic hypermutation suggested commonalities in maturation among all CD4bs antibodies. Fortunately, the required CH235-lineage hypermutation appeared substantially guided by the intrinsic mutability of the VH1-46 gene, which closely resembled VH1-2. We integrated our CH235-lineage findings with a second broadly neutralizing lineage and HIV-1 co-evolution to suggest a vaccination strategy for inducing both lineages.
Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Secuencia de Aminoácidos , Anticuerpos Neutralizantes/química , Linfocitos B/inmunología , Anticuerpos Anti-VIH/química , Proteína gp120 de Envoltorio del VIH/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Alineación de SecuenciaRESUMEN
Development of strategies for induction of HIV-1 broadly neutralizing antibodies (bnAbs) by vaccines is a priority. Determining the steps of bnAb induction in HIV-1-infected individuals who make bnAbs is a key strategy for immunogen design. Here, we study the B cell response in a bnAb-producing individual and report cooperation between two B cell lineages to drive bnAb development. We isolated a virus-neutralizing antibody lineage that targeted an envelope region (loop D) and selected virus escape mutants that resulted in both enhanced bnAb lineage envelope binding and escape mutant neutralization-traits associated with increased B cell antigen drive. Thus, in this individual, two B cell lineages cooperated to induce the development of bnAbs. Design of vaccine immunogens that simultaneously drive both helper and broadly neutralizing B cell lineages may be important for vaccine-induced recapitulation of events that transpire during the maturation of neutralizing antibodies in HIV-1-infected individuals.
Asunto(s)
Vacunas contra el SIDA/química , Vacunas contra el SIDA/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , VIH-1/fisiología , Secuencia de Aminoácidos , Linfocitos B/inmunología , Evasión Inmune , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Alineación de Secuencia , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunologíaRESUMEN
Lineage-based vaccine design is an attractive approach for eliciting broadly neutralizing antibodies (bNAbs) against HIV-1. However, most bNAb lineages studied to date have features indicative of unusual recombination and/or development. From an individual in the prospective RV217 cohort, we identified three lineages of bNAbs targeting the membrane-proximal external region (MPER) of the HIV-1 envelope. Antibodies RV217-VRC42.01, -VRC43.01, and -VRC46.01 used distinct modes of recognition and neutralized 96%, 62%, and 30%, respectively, of a 208-strain virus panel. All three lineages had modest levels of somatic hypermutation and normal antibody-loop lengths and were initiated by the founder virus MPER. The broadest lineage, VRC42, was similar to the known bNAb 4E10. A multimeric immunogen based on the founder MPER activated B cells bearing the unmutated common ancestor of VRC42, with modest maturation of early VRC42 intermediates imparting neutralization breadth. These features suggest that VRC42 may be a promising template for lineage-based vaccine design.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Vacunas contra el SIDA/inmunología , Secuencia de Aminoácidos , Linfocitos B/inmunología , Línea Celular , Células HEK293 , Infecciones por VIH/inmunología , Humanos , Leucocitos Mononucleares , Estudios LongitudinalesRESUMEN
Elicitation of VRC01-class broadly neutralizing antibodies (bnAbs) is an appealing approach for a preventative HIV-1 vaccine. Despite extensive investigations, strategies to induce VRC01-class bnAbs and overcome the barrier posed by the envelope N276 glycan have not been successful. Here, we inferred a high-probability unmutated common ancestor (UCA) of the VRC01 lineage and reconstructed the stages of lineage maturation. Env immunogens designed on reverted VRC01-class bnAbs bound to VRC01 UCA with affinity sufficient to activate naive B cells. Early mutations defined maturation pathways toward limited or broad neutralization, suggesting that focusing the immune response is likely required to steer B cell maturation toward the development of neutralization breadth. Finally, VRC01 lineage bnAbs with long CDR H3s overcame the HIV-1 N276 glycan barrier without shortening their CDR L1, revealing a solution for broad neutralization in which the heavy chain, not CDR L1, is the determinant to accommodate the N276 glycan.
Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Polisacáridos/inmunología , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/genética , Secuencia de Aminoácidos , Anticuerpos Monoclonales/clasificación , Anticuerpos Monoclonales/genética , Anticuerpos Neutralizantes/clasificación , Anticuerpos Neutralizantes/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Sitios de Unión/genética , Anticuerpos ampliamente neutralizantes , Antígenos CD4/genética , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Anticuerpos Anti-VIH , Proteína gp120 de Envoltorio del VIH/genética , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp120 de Envoltorio del VIH/metabolismo , Infecciones por VIH/terapia , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , VIH-1/fisiología , Humanos , Filogenia , Polisacáridos/metabolismo , Homología de Secuencia de AminoácidoRESUMEN
Betacoronaviruses caused the outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, as well as the current pandemic of SARS coronavirus 2 (SARS-CoV-2)1-4. Vaccines that elicit protective immunity against SARS-CoV-2 and betacoronaviruses that circulate in animals have the potential to prevent future pandemics. Here we show that the immunization of macaques with nanoparticles conjugated with the receptor-binding domain of SARS-CoV-2, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV and SARS-CoV-2 (including the B.1.1.7, P.1 and B.1.351 variants). Vaccination of macaques with these nanoparticles resulted in a 50% inhibitory reciprocal serum dilution (ID50) neutralization titre of 47,216 (geometric mean) for SARS-CoV-2, as well as in protection against SARS-CoV-2 in the upper and lower respiratory tracts. Nucleoside-modified mRNAs that encode a stabilized transmembrane spike or monomeric receptor-binding domain also induced cross-neutralizing antibody responses against SARS-CoV and bat coronaviruses, albeit at lower titres than achieved with the nanoparticles. These results demonstrate that current mRNA-based vaccines may provide some protection from future outbreaks of zoonotic betacoronaviruses, and provide a multimeric protein platform for the further development of vaccines against multiple (or all) betacoronaviruses.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , Betacoronavirus/inmunología , COVID-19/inmunología , COVID-19/prevención & control , Resfriado Común/prevención & control , Reacciones Cruzadas/inmunología , Pandemias , Vacunas Virales/inmunología , Adyuvantes Inmunológicos , Administración Intranasal , Animales , COVID-19/epidemiología , Vacunas contra la COVID-19/inmunología , Resfriado Común/inmunología , Resfriado Común/virología , Modelos Animales de Enfermedad , Femenino , Humanos , Macaca/inmunología , Masculino , Modelos Moleculares , Nanopartículas/química , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Tráquea , VacunaciónRESUMEN
How different classes of the B cell antigen receptor (BCR) sense viral antigens used in vaccination protocols is poorly understood. Here, we study antigen binding and sensing of human Ramos B cells expressing a BCR of either the IgM or IgG1 class with specificity for the CD4-binding-site of the envelope (Env) protein of the HIV-1. Both BCRs carry an identical antigen binding site derived from the broad neutralizing antibody (bnAb) CH31. We find a five times higher expression of the IgG1-BCR in comparison to the IgM-BCR on the surface of transfected Ramos B cells. The two BCR classes also differ from each other in their interaction with cognate HIV Env antigens in that the IgG1-BCR and IgM-BCR bind preferentially to polyvalent and monovalent antigens, respectively. By generating an IgM/IgG1 chimeric BCR, we found that the class-specific BCR expression and antigen-sensing behavior can be transferred with the CH1γ domain from the IgG1-BCR to the IgM-BCR. Thus, the class of CH1 domain has an impact on BCR assembly and expression as well as on antigen sensing.
Asunto(s)
VIH-1 , Inmunoglobulina G , Inmunoglobulina M , Receptores de Antígenos de Linfocitos B , Humanos , Inmunoglobulina M/inmunología , Inmunoglobulina G/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/inmunología , VIH-1/inmunología , VIH-1/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Anticuerpos Anti-VIH/inmunología , Dominios Proteicos , Anticuerpos Neutralizantes/inmunologíaRESUMEN
Antibodies perform both neutralizing and non-neutralizing effector functions that protect against certain pathogen-induced diseases. A human antibody directed at the SARS-CoV-2 Spike N-terminal domain (NTD), DH1052, was recently shown to be non-neutralizing, yet it protected mice and cynomolgus macaques from severe disease. The mechanisms of NTD non-neutralizing antibody-mediated protection are unknown. Here we show that Fc effector functions mediate NTD non-neutralizing antibody (non-nAb) protection against SARS-CoV-2 MA10 viral challenge in mice. Though non-nAb prophylactic infusion did not suppress infectious viral titers in the lung as potently as neutralizing antibody (nAb) infusion, disease markers including gross lung discoloration were similar in nAb and non-nAb groups. Fc functional knockout substitutions abolished non-nAb protection and increased viral titers in the nAb group. Fc enhancement increased non-nAb protection relative to WT, supporting a positive association between Fc functionality and degree of protection from SARS-CoV-2 infection. For therapeutic administration of antibodies, non-nAb effector functions contributed to virus suppression and lessening of lung discoloration, but the presence of neutralization was required for optimal protection from disease. This study demonstrates that non-nAbs can utilize Fc-mediated mechanisms to lower viral load and prevent lung damage due to coronavirus infection.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , Fragmentos Fc de Inmunoglobulinas , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , SARS-CoV-2/inmunología , Ratones , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Anticuerpos Antivirales/inmunología , Anticuerpos Neutralizantes/inmunología , Fragmentos Fc de Inmunoglobulinas/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Humanos , Femenino , Dominios Proteicos/inmunología , Carga Viral , Pulmón/virología , Pulmón/inmunología , Pulmón/patologíaRESUMEN
Detailed studies of the broadly neutralizing antibodies (bNAbs) that underlie the best available examples of the humoral immune response to HIV are providing important information for the development of therapies and prophylaxis for HIV-1 infection. Here, we report a CD4-binding site (CD4bs) antibody, named N6, that potently neutralized 98% of HIV-1 isolates, including 16 of 20 that were resistant to other members of its class. N6 evolved a mode of recognition such that its binding was not impacted by the loss of individual contacts across the immunoglobulin heavy chain. In addition, structural analysis revealed that the orientation of N6 permitted it to avoid steric clashes with glycans, which is a common mechanism of resistance. Thus, an HIV-1-specific bNAb can achieve potent, near-pan neutralization of HIV-1, making it an attractive candidate for use in therapy and prophylaxis.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , Sitios de Unión de Anticuerpos/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Especificidad de Anticuerpos , Linfocitos T CD4-Positivos/inmunología , Separación Celular , Proteína gp120 de Envoltorio del VIH/inmunología , HumanosRESUMEN
IMPORTANCE: Multiple SARS-CoV-2 variants of concern have emerged and caused a significant number of infections and deaths worldwide. These variants of concern contain mutations that might significantly affect antigen-targeting by antibodies. It is therefore important to further understand how antibody binding and neutralization are affected by the mutations in SARS-CoV-2 variants. We highlighted how antibody epitope specificity can influence antibody binding to SARS-CoV-2 spike protein variants and neutralization of SARS-CoV-2 variants. We showed that weakened spike binding and neutralization of Beta (B.1.351) and Omicron (BA.1) variants compared to wildtype are not universal among the panel of antibodies and identified antibodies of a specific binding footprint exhibiting consistent enhancement of spike binding and retained neutralization to Beta variant. These data and analysis can inform how antigen-targeting by antibodies might evolve during a pandemic and prepare for potential future sarbecovirus outbreaks.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/metabolismo , COVID-19 , SARS-CoV-2/genética , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
In HIV-1, the ability to mount antibody responses to conserved, neutralizing epitopes is critical for protection. Here we have studied the light chain usage of human and rhesus macaque antibodies targeted to a dominant region of the HIV-1 envelope second variable (V2) region involving lysine (K) 169, the site of immune pressure in the RV144 vaccine efficacy trial. We found that humans and rhesus macaques used orthologous lambda variable gene segments encoding a glutamic acid-aspartic acid (ED) motif for K169 recognition. Structure determination of an unmutated ancestor antibody demonstrated that the V2 binding site was preconfigured for ED motif-mediated recognition prior to maturation. Thus, light chain usage for recognition of the site of immune pressure in the RV144 trial is highly conserved across species. These data indicate that the HIV-1 K169-recognizing ED motif has persisted over the diversification between rhesus macaques and humans, suggesting an evolutionary advantage of this antibody recognition mode.
Asunto(s)
Vacunas contra el SIDA , Anticuerpos Antivirales/metabolismo , Linfocitos B/inmunología , Epítopos de Linfocito B/metabolismo , Proteína gp120 de Envoltorio del VIH/metabolismo , Infecciones por VIH/inmunología , VIH-1/inmunología , Cadenas Ligeras de Inmunoglobulina/metabolismo , Secuencia de Aminoácidos , Animales , Afinidad de Anticuerpos/genética , Células Cultivadas , Ensayos Clínicos como Asunto , Secuencia Conservada/genética , Mapeo Epitopo , Epítopos de Linfocito B/genética , Epítopos de Linfocito B/inmunología , Proteína gp120 de Envoltorio del VIH/genética , Proteína gp120 de Envoltorio del VIH/inmunología , Infecciones por VIH/prevención & control , Humanos , Macaca mulatta , Datos de Secuencia Molecular , Mutación/genética , Filogenia , Unión Proteica/genética , Ingeniería de ProteínasRESUMEN
The RV144 HIV-1 trial of the canary pox vector (ALVAC-HIV) plus the gp120 AIDSVAX B/E vaccine demonstrated an estimated efficacy of 31%, which correlated directly with antibodies to HIV-1 envelope variable regions 1 and 2 (V1-V2). Genetic analysis of trial viruses revealed increased vaccine efficacy against viruses matching the vaccine strain at V2 residue 169. Here, we isolated four V2 monoclonal antibodies from RV144 vaccinees that recognize residue 169, neutralize laboratory-adapted HIV-1, and mediate killing of field-isolate HIV-1-infected CD4(+) T cells. Crystal structures of two of the V2 antibodies demonstrated that residue 169 can exist within divergent helical and loop conformations, which contrasted dramatically with the ß strand conformation previously observed with a broadly neutralizing antibody PG9. Thus, RV144 vaccine-induced immune pressure appears to target a region that may be both sequence variable and structurally polymorphic. Variation may signal sites of HIV-1 envelope vulnerability, providing vaccine designers with new options.
Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Secuencia de Aminoácidos , Sustitución de Aminoácidos/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/metabolismo , Anticuerpos Anti-VIH/química , Anticuerpos Anti-VIH/metabolismo , Proteína gp120 de Envoltorio del VIH/química , Proteína gp120 de Envoltorio del VIH/metabolismo , Humanos , Simulación del Acoplamiento Molecular , Datos de Secuencia Molecular , Péptidos/química , Péptidos/inmunología , Péptidos/metabolismo , Unión Proteica/inmunología , Conformación ProteicaRESUMEN
Small-molecule viral entry inhibitors, such as BMS-626529 (BMS-529), allosterically block CD4 binding to HIV-1 envelope (Env) and inhibit CD4-induced structural changes in Env trimers. Here, we show that the binding of BMS-529 to clade C soluble chimeric gp140 SOSIP (ch.SOSIP) and membrane-bound trimers with intact transmembrane domain (gp150) prevented trimer conformational transitions and enhanced their immunogenicity. When complexed to BMS-529, ch.SOSIP trimers retained their binding to broadly neutralizing antibodies (bNAbs) and to their unmutated common ancestor (UCA) antibodies, while exposure of CD4-induced (CD4i) non-bNAb epitopes was inhibited. BMS-529-complexed gp150 trimers in detergent micelles, which were isolated from CHO cells, bound to bNAbs, including UCA and intermediates of the CD4 binding site (bs) CH103 bNAb lineage, and showed limited exposure of CD4i epitopes and a glycosylation pattern with a preponderance of high-mannose glycans. In rabbits, BMS-529-complexed V3 glycan-targeting ch.SOSIP immunogen induced in the majority of immunized animals higher neutralization titers against both autologous and select high mannose-bearing heterologous tier 2 pseudoviruses than those immunized with the noncomplexed ch.SOSIP. In rhesus macaques, BMS-529 complexed to CD4 bs-targeting ch.SOSIP immunogen induced stronger neutralization against tier 2 pseudoviruses bearing high-mannose glycans than noncomplexed ch.SOSIP trimer immunogen. When immunized with gp150 complexed to BMS-529, rhesus macaques showed neutralization against tier 2 pseudoviruses with targeted glycan deletion and high-mannose glycan enrichment. These results demonstrated that stabilization of Env trimer conformation with BMS-529 improved the immunogenicity of select chimeric SOSIP trimers and elicited tier 2 neutralizing antibodies of higher potency than noncomplexed trimers.IMPORTANCE Soluble forms of HIV-1 envelope trimers exhibit conformational heterogeneity and undergo CD4-induced (CD4i) exposure of epitopes of non-neutralizing antibodies that can potentially hinder induction of broad neutralizing antibody responses. These limitations have been mitigated through recent structure-guided approaches and include trimer-stabilizing mutations that resist trimer conformational transition and exposure of CD4i epitopes. The use of small-molecule viral inhibitors that allosterically block CD4 binding represents an alternative strategy for stabilizing Env trimer in the pre-CD4-triggered state of both soluble and membrane-bound trimers. In this study, we report that the viral entry inhibitor BMS-626529 restricts trimer conformational transition and improves the immunogenicity of select Env trimer immunogens.
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Fármacos Anti-VIH/farmacología , Anticuerpos Neutralizantes/farmacología , Anticuerpos Antivirales/farmacología , Infecciones por VIH/tratamiento farmacológico , Inmunoconjugados/farmacología , Piperazinas/farmacología , Triazoles/farmacología , Animales , Fármacos Anti-VIH/química , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/química , Antígenos CD4/antagonistas & inhibidores , Antígenos CD4/genética , Antígenos CD4/inmunología , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Células CHO , Cricetulus , Glicosilación , Células HEK293 , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , VIH-1/crecimiento & desarrollo , VIH-1/inmunología , Humanos , Inmunoconjugados/química , Macaca mulatta , Piperazinas/química , Multimerización de Proteína , Conejos , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Triazoles/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/antagonistas & inhibidores , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunologíaRESUMEN
Induction of protective antibodies is a critical goal of HIV-1 vaccine development. One strategy is to induce nonneutralizing antibodies (NNAbs) that kill virus-infected cells, as these antibody specificities have been implicated in slowing HIV-1 disease progression and in protection. HIV-1 Env constant region 1 and 2 (C1C2) monoclonal antibodies (MAbs) frequently mediate potent antibody-dependent cellular cytotoxicity (ADCC), making them an important vaccine target. Here, we explore the effect of delayed and repetitive boosting of RV144 vaccine recipients with AIDSVAX B/E on the C1C2-specific MAb repertoire. It was found that boosting increased clonal lineage-specific ADCC breadth and potency. A ligand crystal structure of a vaccine-induced broad and potent ADCC-mediating C1C2-specific MAb showed that it bound a highly conserved Env gp120 epitope. Thus, boosting to affinity mature these types of IgG C1C2-specific antibody responses may be one method by which to make an improved HIV vaccine with higher efficacy than that seen in the RV144 trial.IMPORTANCE Over one million people become infected with HIV-1 each year, making the development of an efficacious HIV-1 vaccine an important unmet medical need. The RV144 human HIV-1 vaccine regimen is the only HIV-1 clinical trial to date to demonstrate vaccine efficacy. An area of focus has been on identifying ways by which to improve upon RV144 vaccine efficacy. The RV305 HIV-1 vaccine regimen was a follow-up boost of RV144 vaccine recipients that occurred 6 to 8 years after the conclusion of RV144. Our study focused on the effect of delayed boosting in humans on the vaccine-induced Env constant region 1 and 2 (C1C2)-specific antibody repertoire. It was found that boosting with an HIV-1 Env vaccine increased C1C2-specific antibody-dependent cellular cytotoxicity potency and breadth.
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Vacunas contra el SIDA/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Anticuerpos Monoclonales/inmunología , Formación de Anticuerpos/inmunología , Especificidad de Anticuerpos/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Epítopos/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/ultraestructura , Proteína gp120 de Envoltorio del VIH/ultraestructura , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Inmunización Secundaria/métodos , Inmunoglobulina G/inmunologíaRESUMEN
Viral glycoproteins are a primary target for host antibody responses. However, glycans on viral glycoproteins can hinder antibody recognition since they are self glycans derived from the host biosynthesis pathway. During natural HIV-1 infection, neutralizing antibodies are made against glycans on HIV-1 envelope glycoprotein (Env). However, such antibodies are rarely elicited with vaccination. Previously, the vaccine-induced, macaque antibody DH501 was isolated and shown to bind to high mannose glycans on HIV-1 Env. Understanding how DH501 underwent affinity maturation to recognize glycans could inform vaccine induction of HIV-1 glycan antibodies. Here, we show that DH501 Env glycan reactivity is mediated by both germline-encoded residues that contact glycans, and somatic mutations that increase antibody paratope flexibility. Only somatic mutations in the heavy chain were required for glycan reactivity. The paratope conformation was fragile as single mutations within the immunoglobulin fold or complementarity determining regions were sufficient for eliminating antibody function. Taken together, the initial germline VHDJH rearrangement generated contact residues capable of binding glycans, and somatic mutations were required to form a flexible paratope with a cavity conducive to HIV-1 envelope glycan binding. The requirement for the presence of most somatic mutations across the heavy chain variable region provides one explanation for the difficulty in inducing anti-Env glycan antibodies with HIV-1 Env vaccination.
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Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Polisacáridos/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/genética , Animales , Anticuerpos Neutralizantes/genética , Anticuerpos Neutralizantes/inmunología , Secuencia de Bases , Infecciones por VIH/inmunología , Humanos , MutaciónRESUMEN
The CD4 binding site (CD4bs) of the HIV-1 envelope glycoprotein is susceptible to multiple lineages of broadly neutralizing antibodies (bnAbs) that are attractive to elicit with vaccines. The CH235 lineage (VH1-46) of CD4bs bnAbs is particularly attractive because the most mature members neutralize 90% of circulating strains, do not possess long HCDR3 regions, and do not contain insertions and deletions that may be difficult to induce. We used virus neutralization to measure the interaction of CH235 unmutated common ancestor (CH235 UCA) with functional Env trimers on infectious virions to guide immunogen design for this bnAb lineage. Two Env mutations were identified, one in loop D (N279K) and another in V5 (G458Y), that acted synergistically to render autologous CH505 transmitted/founder virus susceptible to neutralization by CH235 UCA. Man5-enriched N-glycans provided additional synergy for neutralization. CH235 UCA bound with nanomolar affinity to corresponding soluble native-like Env trimers as candidate immunogens. A cryo-EM structure of CH235 UCA bound to Man5-enriched CH505.N279K.G458Y.SOSIP.664 revealed interactions of the antibody light chain complementarity determining region 3 (CDR L3) with the engineered Env loops D and V5. These results demonstrate that virus neutralization can directly inform vaccine design and suggest a germline targeting and reverse engineering strategy to initiate and mature the CH235 bnAb lineage.