RESUMO
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.
Assuntos
Vacinas contra a AIDS , Anticorpos Neutralizantes , Linfócitos B , Anticorpos Anti-HIV , HIV-1 , Humanos , Vacinas contra a AIDS/imunologia , HIV-1/imunologia , Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Linhagem da Célula , Lipossomos , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Mutação , Proteína gp41 do Envelope de HIV/imunologiaRESUMO
The mpox outbreak of 2022-2023 involved rapid global spread in men who have sex with men. We infected 18 rhesus macaques with mpox by the intravenous, intradermal, and intrarectal routes and observed robust antibody and T cell responses following all three routes of infection. Numerous skin lesions and high plasma viral loads were observed following intravenous and intradermal infection. Skin lesions peaked on day 10 and resolved by day 28 following infection. On day 28, we re-challenged all convalescent and 3 naive animals with mpox. All convalescent animals were protected against re-challenge. Transcriptomic studies showed upregulation of innate and inflammatory responses and downregulation of collagen formation and extracellular matrix organization following challenge, as well as rapid activation of T cell and plasma cell responses following re-challenge. These data suggest key mechanistic insights into mpox pathogenesis and immunity. This macaque model should prove useful for evaluating mpox vaccines and therapeutics.
Assuntos
Macaca mulatta , Monkeypox virus , Mpox , Animais , Humanos , Masculino , Homossexualidade Masculina , Mpox/imunologia , Minorias Sexuais e de Gênero , Monkeypox virus/fisiologiaRESUMO
Monoclonal antibodies (mAbs) are a focus in vaccine and therapeutic design to counteract severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants. Here, we combined B cell sorting with single-cell VDJ and RNA sequencing (RNA-seq) and mAb structures to characterize B cell responses against SARS-CoV-2. We show that the SARS-CoV-2-specific B cell repertoire consists of transcriptionally distinct B cell populations with cells producing potently neutralizing antibodies (nAbs) localized in two clusters that resemble memory and activated B cells. Cryo-electron microscopy structures of selected nAbs from these two clusters complexed with SARS-CoV-2 spike trimers show recognition of various receptor-binding domain (RBD) epitopes. One of these mAbs, BG10-19, locks the spike trimer in a closed conformation to potently neutralize SARS-CoV-2, the recently arising mutants B.1.1.7 and B.1.351, and SARS-CoV and cross-reacts with heterologous RBDs. Together, our results characterize transcriptional differences among SARS-CoV-2-specific B cells and uncover cross-neutralizing Ab targets that will inform immunogen and therapeutic design against coronaviruses.
Assuntos
Anticorpos Neutralizantes/imunologia , Linfócitos B/metabolismo , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Anticorpos Antivirais/sangue , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/metabolismo , Reações Antígeno-Anticorpo , Linfócitos B/citologia , Linfócitos B/virologia , COVID-19/patologia , COVID-19/virologia , Microscopia Crioeletrônica , Cristalografia por Raios X , Perfilação da Expressão Gênica , Humanos , Imunoglobulina A/imunologia , Região Variável de Imunoglobulina/química , Região Variável de Imunoglobulina/genética , Domínios Proteicos/imunologia , Multimerização Proteica , Estrutura Quaternária de Proteína , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Análise de Sequência de RNA , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Memory B cell reserves can generate protective antibodies against repeated SARS-CoV-2 infections, but with unknown reach from original infection to antigenically drifted variants. We charted memory B cell receptor-encoded antibodies from 19 COVID-19 convalescent subjects against SARS-CoV-2 spike (S) and found seven major antibody competition groups against epitopes recurrently targeted across individuals. Inclusion of published and newly determined structures of antibody-S complexes identified corresponding epitopic regions. Group assignment correlated with cross-CoV-reactivity breadth, neutralization potency, and convergent antibody signatures. Although emerging SARS-CoV-2 variants of concern escaped binding by many members of the groups associated with the most potent neutralizing activity, some antibodies in each of those groups retained affinity-suggesting that otherwise redundant components of a primary immune response are important for durable protection from evolving pathogens. Our results furnish a global atlas of S-specific memory B cell repertoires and illustrate properties driving viral escape and conferring robustness against emerging variants.
RESUMO
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.
Assuntos
Anticorpos Neutralizantes/imunologia , HIV-1/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Polissacarídeos/imunologia , SARS-CoV-2/imunologia , Vírus da Imunodeficiência Símia/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Linfócitos B/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , COVID-19/imunologia , Dimerização , Epitopos/imunologia , Glicosilação , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Humanos , Fragmentos Fab das Imunoglobulinas/química , Macaca mulatta , Polissacarídeos/química , Receptores de Antígenos de Linfócitos B/química , Vírus da Imunodeficiência Símia/genética , Vacinas/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genéticaRESUMO
Antibodies are key immune effectors that confer protection against pathogenic threats. The nature and longevity of the antibody response to SARS-CoV-2 infection are not well defined. We charted longitudinal antibody responses to SARS-CoV-2 in 92 subjects after symptomatic COVID-19. Antibody responses to SARS-CoV-2 are unimodally distributed over a broad range, with symptom severity correlating directly with virus-specific antibody magnitude. Seventy-six subjects followed longitudinally to â¼100 days demonstrated marked heterogeneity in antibody duration dynamics. Virus-specific IgG decayed substantially in most individuals, whereas a distinct subset had stable or increasing antibody levels in the same time frame despite similar initial antibody magnitudes. These individuals with increasing responses recovered rapidly from symptomatic COVID-19 disease, harbored increased somatic mutations in virus-specific memory B cell antibody genes, and had persistent higher frequencies of previously activated CD4+ T cells. These findings illuminate an efficient immune phenotype that connects symptom clearance speed to differential antibody durability dynamics.
Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos , Linfócitos T CD4-Positivos/imunologia , COVID-19 , Imunoglobulina G/imunologia , Ativação Linfocitária , Mutação , COVID-19/genética , COVID-19/imunologia , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologiaRESUMO
Several HIV-1 and SIV vaccine candidates have shown partial protection against viral challenges in rhesus macaques. However, the protective efficacy of vaccine-elicited polyclonal antibodies has not previously been demonstrated in adoptive transfer studies in nonhuman primates. In this study, we show that passive transfer of purified antibodies from vaccinated macaques can protect naive animals against SIVmac251 challenges. We vaccinated 30 rhesus macaques with Ad26-SIV Env/Gag/Pol and SIV Env gp140 protein vaccines and assessed the induction of antibody responses and a putative protective signature. This signature included multiple antibody functions and correlated with upregulation of interferon pathways in vaccinated animals. Adoptive transfer of purified immunoglobulin G (IgG) from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naive recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies in this model, even in the absence of virus neutralization.
Assuntos
Imunização Passiva/métodos , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Produtos do Gene env/imunologia , Produtos do Gene gag/imunologia , Produtos do Gene pol/imunologia , HIV-1/imunologia , Imunoglobulina G/imunologia , Macaca mulatta/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologiaRESUMO
Broadly neutralizing antibodies (bNAbs) represent a promising approach to prevent and treat HIV-1 infection. However, viral escape through mutation of the HIV-1 envelope glycoprotein (Env) limits clinical applications. Here we describe 1-18, a new VH1-46-encoded CD4 binding site (CD4bs) bNAb with outstanding breadth (97%) and potency (GeoMean IC50 = 0.048 µg/mL). Notably, 1-18 is not susceptible to typical CD4bs escape mutations and effectively overcomes HIV-1 resistance to other CD4bs bNAbs. Moreover, mutational antigenic profiling uncovered restricted pathways of HIV-1 escape. Of most promise for therapeutic use, even 1-18 alone fully suppressed viremia in HIV-1-infected humanized mice without selecting for resistant viral variants. A 2.5-Å cryo-EM structure of a 1-18-BG505SOSIP.664 Env complex revealed that these characteristics are likely facilitated by a heavy-chain insertion and increased inter-protomer contacts. The ability of 1-18 to effectively restrict HIV-1 escape pathways provides a new option to successfully prevent and treat HIV-1 infection.
Assuntos
Anticorpos Amplamente Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Anticorpos Monoclonais/imunologia , Sítios de Ligação , Antígenos CD4/metabolismo , Células CHO , Estudos de Coortes , Cricetulus , Epitopos/imunologia , Feminino , Células HEK293 , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Mutação , Ligação Proteica/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/genéticaRESUMO
Anti-HIV-1 envelope broadly neutralizing monoclonal antibodies (bNAbs) isolated from memory B cells may not fully represent HIV-1-neutralizing profiles measured in plasma. Accordingly, we characterized near-pan-neutralizing antibodies extracted directly from the plasma of two "elite neutralizers." Circulating anti-gp120 polyclonal antibodies were deconvoluted using proteomics to guide lineage analysis of bone marrow plasma cells. In both subjects, a single lineage of anti-CD4-binding site (CD4bs) antibodies explained the plasma-neutralizing activity. Importantly, members of these lineages potently neutralized 89%-100% of a multi-tier 117 pseudovirus panel, closely matching the specificity and breadth of the circulating antibodies. X-ray crystallographic analysis of one monoclonal, N49P7, suggested a unique ability to bypass the CD4bs Phe43 cavity, while reaching deep into highly conserved residues of Layer 3 of the gp120 inner domain, likely explaining its extreme potency and breadth. Further direct analyses of plasma anti-HIV-1 bNAbs should provide new insights for developing antibody-based antiviral agents and vaccines.
Assuntos
Anticorpos Neutralizantes/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/metabolismo , Sequência de Aminoácidos , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/química , Sítios de Ligação , Antígenos CD4/química , Antígenos CD4/metabolismo , Cristalografia por Raios X , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/genética , Humanos , Simulação de Dinâmica Molecular , Ligação Proteica , Estrutura Terciária de Proteína , RNA Viral/sangue , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologiaRESUMO
Non-neutralizing antibodies (nnAbs) to HIV-1 show little measurable activity in prevention or therapy in animal models yet were the only correlate of protection in the RV144 vaccine trial. To investigate the role of nnAbs on HIV-1 infection in vivo, we devised a replication-competent HIV-1 reporter virus that expresses a heterologous HA-tag on the surface of infected cells and virions. Anti-HA antibodies bind to, but do not neutralize, the reporter virus in vitro. However, anti-HA protects against infection in humanized mice and strongly selects for nnAb-resistant viruses in an entirely Fc-dependent manner. Similar results were also obtained with tier 2 HIV-1 viruses using a human anti-gp41 nnAb, 246D. While nnAbs are demonstrably less effective than broadly neutralizing antibodies (bNAbs) against HIV-1 in vitro and in vivo, the data show that nnAbs can protect against and alter the course of HIV-1 infection in vivo. PAPERCLIP.
Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Vacinas contra a AIDS/imunologia , Animais , Antígenos CD4/química , Antígenos CD4/metabolismo , Modelos Animais de Doenças , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/genética , Humanos , Camundongos , Mutação , Receptores Fc/imunologia , Linfócitos T/virologiaRESUMO
Broadly neutralizing antibodies (bNAbs) against the HIV-1 envelope glycoprotein (Env) suppress viremia in animal models of HIV-1 and humans. To achieve potent activity without the emergence of viral escape mutants, co-administration of different bNAbs is necessary to target distinct epitopes essential for viral fitness. Here, we report the development of bispecific anti-Env neutralizing antibodies (biNAbs) with potent activity. Synergistic activity of biNAbs was achieved by combining an engineered hinge domain of IgG3 to increase Fab domain flexibility necessary for hetero-bivalent binding to the Env trimer while retaining the functional properties of the IgG1-Fc. Compared to unmodified biNAbs, hinge domain variants exhibited substantially improved neutralization activity, with particular combinations showing evidence of synergistic neutralization potency in vitro and enhanced in vivo therapeutic activity in HIV-1-infected humanized mice. These findings suggest innovative strategies for generating biNAbs with enhanced neutralization breadth and potency, representing ideal candidate molecules for the control of HIV-1 infection.
Assuntos
Anticorpos Biespecíficos/química , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Animais , Anticorpos Biespecíficos/imunologia , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Epitopos , Proteína gp120 do Envelope de HIV/química , Infecções por HIV/prevenção & controle , Infecções por HIV/terapia , Humanos , Imunização Passiva , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fab das Imunoglobulinas/imunologia , Imunoglobulina G/química , Imunoglobulina G/imunologia , CamundongosRESUMO
While the search for an efficacious HIV-1 vaccine remains elusive, emergence of a new generation of virus-neutralizing monoclonal antibodies (mAbs) has re-ignited the field of passive immunization for HIV-1 prevention. However, the plasticity of HIV-1 demands additional improvements to these mAbs to better ensure their clinical utility. Here, we report engineered bispecific antibodies that are the most potent and broad HIV-neutralizing antibodies to date. One bispecific antibody, 10E8V2.0/iMab, neutralized 118 HIV-1 pseudotyped viruses tested with a mean 50% inhibitory concentration (IC50) of 0.002 µg/mL. 10E8V2.0/iMab also potently neutralized 99% of viruses in a second panel of 200 HIV-1 isolates belonging to clade C, the dominant subtype accounting for â¼50% of new infections worldwide. Importantly, 10E8V2.0/iMab reduced virus load substantially in HIV-1-infected humanized mice and also provided complete protection when administered prior to virus challenge. These bispecific antibodies hold promise as novel prophylactic and/or therapeutic agents in the fight against HIV-1.
Assuntos
Anticorpos Biespecíficos/imunologia , Anticorpos Neutralizantes/imunologia , Proteína gp160 do Envelope de HIV/imunologia , HIV-1/imunologia , Animais , Anticorpos Biespecíficos/química , Anticorpos Monoclonais/química , Anticorpos Neutralizantes/química , Proteína gp160 do Envelope de HIV/química , Infecções por HIV/prevenção & controle , Infecções por HIV/terapia , Humanos , Imunização Passiva , CamundongosRESUMO
Antibodies developed during HIV-1 infection lose efficacy as the viral spike mutates. We postulated that anti-HIV-1 antibodies primarily bind monovalently because HIV's low spike density impedes bivalent binding through inter-spike crosslinking, and the spike structure prohibits bivalent binding through intra-spike crosslinking. Monovalent binding reduces avidity and potency, thus expanding the range of mutations permitting antibody evasion. To test this idea, we engineered antibody-based molecules capable of bivalent binding through intra-spike crosslinking. We used DNA as a "molecular ruler" to measure intra-epitope distances on virion-bound spikes and construct intra-spike crosslinking molecules. Optimal bivalent reagents exhibited up to 2.5 orders of magnitude increased potency (>100-fold average increases across virus panels) and identified conformational states of virion-bound spikes. The demonstration that intra-spike crosslinking lowers the concentration of antibodies required for neutralization supports the hypothesis that low spike densities facilitate antibody evasion and the use of molecules capable of intra-spike crosslinking for therapy or passive protection.
Assuntos
Anticorpos Neutralizantes/química , Anticorpos Anti-HIV/química , HIV-1 , Fragmentos Fab das Imunoglobulinas/química , Imunoglobulina G/química , Anticorpos Neutralizantes/imunologia , Reagentes de Ligações Cruzadas/metabolismo , Cristalografia por Raios X , Epitopos , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Imunoglobulina G/imunologia , Engenharia de ProteínasRESUMO
A subset of individuals infected with HIV-1 develops broadly neutralizing antibodies (bNAbs) that can prevent infection, but it has not yet been possible to elicit these antibodies by immunization. To systematically explore how immunization might be tailored to produce them, we generated mice expressing the predicted germline or mature heavy chains of a potent bNAb to the CD4 binding site (CD4bs) on the HIV-1 envelope glycoprotein (Env). Immunogens specifically designed to activate B cells bearing germline antibodies are required to initiate immune responses, but they do not elicit bNAbs. In contrast, native-like Env trimers fail to activate B cells expressing germline antibodies but elicit bNAbs by selecting for a restricted group of light chains bearing specific somatic mutations that enhance neutralizing activity. The data suggest that vaccination to elicit anti-HIV-1 antibodies will require immunization with a succession of related immunogens.
Assuntos
Anticorpos Neutralizantes/genética , Anticorpos Antivirais/genética , Técnicas de Introdução de Genes , HIV-1/imunologia , Cadeias Pesadas de Imunoglobulinas/genética , Animais , Antígenos Virais , Linfócitos B/imunologia , Antígenos CD4/metabolismo , Infecções por HIV/imunologia , Humanos , Camundongos , Mutação , Baço/citologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismoRESUMO
Broadly neutralizing antibodies (bNAbs) against HIV-1 provide both effective pre-exposure prophylaxis and treatment of HIV-1 infection in murine and nonhuman primate models, suggesting their potential use in humans. Although much is known about the role of variable domains in the neutralization breadth and potency of these bNAbs, the contribution of Fc domains to their activities is, by contrast, poorly characterized. Assessment of the in vivo activity of several bNAbs revealed that FcγR-mediated effector function contributes substantially to their capacity to block viral entry, suppress viremia, and confer therapeutic activity. Enhanced in vivo potency of anti-HIV-1 bNAbs was associated with preferential engagement of activating, but not inhibitory FcγRs, and Fc domain-engineered bNAb variants with selective binding capacity for activating FcγRs displayed augmented protective activity. These findings reveal key roles for Fc effector function in the in vivo activity of anti-HIV-1 bNAbs and provide strategies for generating bNAbs with improved efficacy.
Assuntos
Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1 , Animais , Modelos Animais de Doenças , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Imunoglobulina G/imunologia , Camundongos , Primatas , Receptores de IgG/metabolismo , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Latent reservoirs of HIV-1-infected cells are refractory to antiretroviral therapies (ART) and remain the major barrier to curing HIV-1. Because latently infected cells are long-lived, immunologically invisible, and may undergo homeostatic proliferation, a "shock and kill" approach has been proposed to eradicate this reservoir by combining ART with inducers of viral transcription. However, all attempts to alter the HIV-1 reservoir in vivo have failed to date. Using humanized mice, we show that broadly neutralizing antibodies (bNAbs) can interfere with establishment of a silent reservoir by Fc-FcR-mediated mechanisms. In established infection, bNAbs or bNAbs plus single inducers are ineffective in preventing viral rebound. However, bNAbs plus a combination of inducers that act by independent mechanisms synergize to decrease the reservoir as measured by viral rebound. Thus, combinations of inducers and bNAbs constitute a therapeutic strategy that impacts the establishment and maintenance of the HIV-1 reservoir in humanized mice.
Assuntos
Anticorpos Neutralizantes/administração & dosagem , Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Latência Viral/efeitos dos fármacos , Animais , Fármacos Anti-HIV/uso terapêutico , Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígeno CTLA-4/administração & dosagem , Infecções por HIV/virologia , HIV-1/genética , HIV-1/fisiologia , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Humanos , Ácidos Hidroxâmicos/administração & dosagem , Fragmentos Fc das Imunoglobulinas/imunologia , Camundongos , Receptores Fc/imunologia , VorinostatRESUMO
Broadly neutralizing antibodies (bNAbs) against HIV-1 envelope (Env) inform vaccine design and are potential therapeutic agents. We identified SF12 and related bNAbs with up to 62% neutralization breadth from an HIV-infected donor. SF12 recognized a glycan-dominated epitope on Env's silent face and was potent against clade AE viruses, which are poorly covered by V3-glycan bNAbs. A 3.3Å cryo-EM structure of a SF12-Env trimer complex showed additional contacts to Env protein residues by SF12 compared with VRC-PG05, the only other known donor-derived silentface antibody, explaining SF12's increased neutralization breadth, potency, and resistance to Env mutation routes. Asymmetric binding of SF12 was associated with distinct N-glycan conformations across Env protomers, demonstrating intra-Env glycan heterogeneity. Administrating SF12 to HIV-1-infected humanized mice suppressed viremia and selected for viruses lacking the N448gp120 glycan. Effective bNAbs can therefore be raised against HIV-1 Env's silent face, suggesting their potential for HIV-1 prevention, therapy, and vaccine development.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/isolamento & purificação , Afinidade de Anticorpos/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Epitopos/química , Epitopos/imunologia , Glicosilação , Anticorpos Anti-HIV/isolamento & purificação , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , Humanos , Modelos Moleculares , Filogenia , Polissacarídeos/química , Polissacarídeos/metabolismo , Ligação Proteica/imunologia , Conformação Proteica , 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/metabolismoRESUMO
Broadly neutralizing antibodies (bNAbs) to HIV-1 can prevent infection and are therefore of great importance for HIV-1 vaccine design. Notably, bNAbs are highly somatically mutated and generated by a fraction of HIV-1-infected individuals several years after infection. Antibodies typically accumulate mutations in the complementarity determining region (CDR) loops, which usually contact the antigen. The CDR loops are scaffolded by canonical framework regions (FWRs) that are both resistant to and less tolerant of mutations. Here, we report that in contrast to most antibodies, including those with limited HIV-1 neutralizing activity, most bNAbs require somatic mutations in their FWRs. Structural and functional analyses reveal that somatic mutations in FWR residues enhance breadth and potency by providing increased flexibility and/or direct antigen contact. Thus, in bNAbs, FWRs play an essential role beyond scaffolding the CDR loops and their unusual contribution to potency and breadth should be considered in HIV-1 vaccine design.
Assuntos
Vacinas contra a AIDS/imunologia , Desenho de Fármacos , Anticorpos Anti-HIV/imunologia , HIV-1 , Mutação , Vacinas contra a AIDS/química , Vacinas contra a AIDS/genética , Sequência de Aminoácidos , Anticorpos Neutralizantes , Regiões Determinantes de Complementaridade , Cristalografia por Raios X , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/genética , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
The global diversity of HIV-1 represents a critical challenge facing HIV-1 vaccine development. HIV-1 mosaic antigens are bioinformatically optimized immunogens designed for improved coverage of HIV-1 diversity. However, the protective efficacy of such global HIV-1 vaccine antigens has not previously been evaluated. Here, we demonstrate the capacity of bivalent HIV-1 mosaic antigens to protect rhesus monkeys against acquisition of infection following heterologous challenges with the difficult-to-neutralize simian-human immunodeficiency virus SHIV-SF162P3. Adenovirus/poxvirus and adenovirus/adenovirus vector-based vaccines expressing HIV-1 mosaic Env, Gag, and Pol afforded a significant reduction in the per-exposure acquisition risk following repetitive, intrarectal SHIV-SF162P3 challenges. Protection against acquisition of infection correlated with vaccine-elicited binding, neutralizing, and functional nonneutralizing antibodies, suggesting that the coordinated activity of multiple antibody functions may contribute to protection against difficult-to-neutralize viruses. These data demonstrate the protective efficacy of HIV-1 mosaic antigens and suggest a potential strategy for the development of a global HIV-1 vaccine. PAPERCLIP:
Assuntos
Vacinas contra a AIDS/imunologia , HIV-1 , Animais , Formação de Anticorpos , Feminino , Antígenos HIV/imunologia , Proteínas do Vírus da Imunodeficiência Humana/imunologia , Imunidade Celular , Macaca mulatta , Masculino , Dados de Sequência Molecular , Organismos Livres de Patógenos EspecíficosRESUMO
Antiretroviral therapy is highly effective in suppressing human immunodeficiency virus (HIV)1. However, eradication of the virus in individuals with HIV has not been possible to date2. Given that HIV suppression requires life-long antiretroviral therapy, predominantly on a daily basis, there is a need to develop clinically effective alternatives that use long-acting antiviral agents to inhibit viral replication3. Here we report the results of a two-component clinical trial involving the passive transfer of two HIV-specific broadly neutralizing monoclonal antibodies, 3BNC117 and 10-1074. The first component was a randomized, double-blind, placebo-controlled trial that enrolled participants who initiated antiretroviral therapy during the acute/early phase of HIV infection. The second component was an open-label single-arm trial that enrolled individuals with viraemic control who were naive to antiretroviral therapy. Up to 8 infusions of 3BNC117 and 10-1074, administered over a period of 24 weeks, were well tolerated without any serious adverse events related to the infusions. Compared with the placebo, the combination broadly neutralizing monoclonal antibodies maintained complete suppression of plasma viraemia (for up to 43 weeks) after analytical treatment interruption, provided that no antibody-resistant HIV was detected at the baseline in the study participants. Similarly, potent HIV suppression was seen in the antiretroviral-therapy-naive study participants with viraemia carrying sensitive virus at the baseline. Our data demonstrate that combination therapy with broadly neutralizing monoclonal antibodies can provide long-term virological suppression without antiretroviral therapy in individuals with HIV, and our experience offers guidance for future clinical trials involving next-generation antibodies with long half-lives.