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1.
Cell Host Microbe ; 32(5): 693-709.e7, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38670093

RESUMO

A major goal of HIV-1 vaccine development is the induction of broadly neutralizing antibodies (bnAbs). Although success has been achieved in initiating bnAb B cell lineages, design of boosting immunogens that select for bnAb B cell receptors with improbable mutations required for bnAb affinity maturation remains difficult. Here, we demonstrate a process for designing boosting immunogens for a V3-glycan bnAb B cell lineage. The immunogens induced affinity-matured antibodies by selecting for functional improbable mutations in bnAb precursor knockin mice. Moreover, we show similar success in prime and boosting with nucleoside-modified mRNA-encoded HIV-1 envelope trimer immunogens, with improved selection by mRNA immunogens of improbable mutations required for bnAb binding to key envelope glycans. These results demonstrate the ability of both protein and mRNA prime-boost immunogens for selection of rare B cell lineage intermediates with neutralizing breadth after bnAb precursor expansion, a key proof of concept and milestone toward development of an HIV-1 vaccine.


Assuntos
Vacinas contra a AIDS , Anticorpos Neutralizantes , Linfócitos B , Anticorpos Anti-HIV , HIV-1 , Vacinas contra a AIDS/imunologia , Vacinas contra a AIDS/genética , Animais , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , HIV-1/genética , Camundongos , Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Humanos , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Anticorpos Amplamente Neutralizantes/imunologia , Mutação , Desenvolvimento de Vacinas , Imunização Secundária , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
2.
Cell Rep ; 38(11): 110514, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35294883

RESUMO

The success of nucleoside-modified mRNAs in lipid nanoparticles (mRNA-LNP) as COVID-19 vaccines heralded a new era of vaccine development. For HIV-1, multivalent envelope (Env) trimer protein nanoparticles are superior immunogens compared with trimers alone for priming of broadly neutralizing antibody (bnAb) B cell lineages. The successful expression of complex multivalent nanoparticle immunogens with mRNAs has not been demonstrated. Here, we show that mRNAs can encode antigenic Env trimers on ferritin nanoparticles that initiate bnAb precursor B cell expansion and induce serum autologous tier 2 neutralizing activity in bnAb precursor VH + VL knock-in mice. Next-generation sequencing demonstrates acquisition of critical mutations, and monoclonal antibodies that neutralize heterologous HIV-1 isolates are isolated. Thus, mRNA-LNP can encode complex immunogens and may be of use in design of germline-targeting and sequential boosting immunogens for HIV-1 vaccine development.


Assuntos
Vacinas contra a AIDS , COVID-19 , HIV-1 , Nanopartículas , Animais , Anticorpos Monoclonais , Anticorpos Neutralizantes , Vacinas contra COVID-19 , Epitopos , Ferritinas/genética , Anticorpos Anti-HIV , Humanos , Lipossomos , Camundongos , RNA Mensageiro , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
3.
Cell Rep ; 36(7): 109561, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34407396

RESUMO

Elicitation of broadly neutralizing antibodies (bnAbs) by an HIV vaccine will involve priming the immune system to activate antibody precursors, followed by boosting immunizations to select for antibodies with functional features required for neutralization breadth. The higher the number of acquired mutations necessary for function, the more convoluted are the antibody developmental pathways. HIV bnAbs acquire a large number of somatic mutations, but not all mutations are functionally important. In this study, we identify a minimal subset of mutations sufficient for the function of the naturally occurring V3-glycan bnAb DH270.6. Using antibody library screening, candidate envelope immunogens that interact with DH270.6-like antibodies containing this set of key mutations are identified and selected in vitro. Our results demonstrate that less complex B cell evolutionary pathways than those naturally observed exist for the induction of HIV bnAbs by vaccination, and they establish rational approaches to identify boosting candidate immunogens.


Assuntos
Anticorpos Neutralizantes/imunologia , Linfócitos B/citologia , Linhagem da Célula , Mutação/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Sequência de Aminoácidos , Linhagem Celular , Humanos , Mutagênese/genética , Ligação Proteica , Vacinação , Produtos do Gene env do Vírus da Imunodeficiência Humana/química
4.
bioRxiv ; 2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34401876

RESUMO

The success of nucleoside-modified mRNAs in lipid nanoparticles (mRNA-LNP) as COVID-19 vaccines heralded a new era of vaccine development. For HIV-1, multivalent envelope (Env) trimer protein nanoparticles are superior immunogens compared to trimers alone for priming of broadly neutralizing antibody (bnAb) B cell lineages. The successful expression of complex multivalent nanoparticle immunogens with mRNAs has not been demonstrated. Here we show that mRNAs can encode antigenic Env trimers on ferritin nanoparticles that initiate bnAb precursor B cell expansion and induce serum autologous tier 2 neutralizing activity in bnAb precursor VH + VL knock-in mice. Next generation sequencing demonstrated acquisition of critical mutations, and monoclonal antibodies that neutralized heterologous HIV-1 isolates were isolated. Thus, mRNA-LNP can encode complex immunogens and are of use in design of germline-targeting and sequential boosting immunogens for HIV-1 vaccine development.

5.
Immunohorizons ; 4(11): 713-728, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33172842

RESUMO

Rab11 recycling endosomes are involved in immunological synaptic functions, but the roles of Rab11 family-interacting protein 5 (Rab11Fip5), one of the Rab11 effectors, in the immune system remain obscure. Our previous study demonstrated that RAB11FIP5 transcripts are significantly elevated in PBMCs from HIV-1-infected individuals, making broadly HIV-1-neutralizing Abs compared with those without broadly neutralizing Abs; however, the role of Rab11FiP5 in immune functions remains unclear. In this study, a RAB11FIP5 gene knockout (RAB11FIP5 -/-) mouse model was employed to study the role of Rab11Fip5 in immune responses. RAB11FIP5 -/- mice exhibited no perturbation in lymphoid tissue cell subsets, and Rab11Fip5 was not required for serum Ab induction following HIV-1 envelope immunization, Ab transcytosis to mucosal sites, or survival after influenza challenge. However, differences were observed in multiple transcripts, including cytokine genes, in lymphocyte subsets from envelope-immunized RAB11FIP5 -/- versus control mice. These included alterations in several genes in NK cells that mirrored observations in NKs from HIV-infected humans expressing less RAB11FIP5, although Rab11Fip5 was dispensable for NK cell cytolytic activity. Notably, immunized RAB11FIP5 -/- mice had lower IL4 expression in CD4+ T follicular helper cells and showed lower TNF expression in CD8+ T cells. Likewise, TNF-α production by human CD8+ T cells correlated with PBMC RAB11FIP5 expression. These observations in RAB11FIP5 -/- mice suggest a role for Rab11Fip5 in regulating cytokine responses.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Anticorpos Neutralizantes/imunologia , Infecções por HIV/imunologia , Transcriptoma , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Feminino , Infecções por HIV/fisiopatologia , HIV-1/patogenicidade , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
6.
Nat Commun ; 10(1): 654, 2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30737386

RESUMO

Somatic mutations within antibody variable and framework regions (FWR) can alter thermostability and structural flexibility, but their impact on functional potency is unclear. Here we study thermostability and use molecular dynamics (MD) simulations to assess the role of FWR mutations during maturation of HIV-1 broadly neutralizing antibodies (bnAbs). The tested bnAbs show lower thermostability than their unmutated ancestor antibodies. FWR mutations in the Fab elbow region are frequently observed in HIV-1 bnAbs and MD simulations show that such FWR mutations alter interdomain flexibility in two HIV-1 bnAbs. In a CD4-binding site lineage, reversion mutations result in a loss of neutralization potency in an early intermediate and affinity-matured bnAb against autologous and heterologous Tier-2 viruses, respectively. Elbow region reversion mutations in a glycan-V3 bnAb modestly reduces potency against an autologous virus isolate. Thus, selection of mutations in the Fab elbow region impacts interdomain conformational flexibility and paratope plasticity during bnAb development.


Assuntos
Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/imunologia , Mutação/genética , Varredura Diferencial de Calorimetria , Dicroísmo Circular , HIV-1/imunologia , Humanos , Simulação de Dinâmica Molecular , Testes de Neutralização , Ressonância de Plasmônio de Superfície
7.
Immunity ; 49(6): 1162-1174.e8, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30552024

RESUMO

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.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Polissacarídeos/imunologia , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/genética , Sequência de Aminoácidos , Anticorpos Monoclonais/classificação , Anticorpos Monoclonais/genética , Anticorpos Neutralizantes/classificação , Anticorpos Neutralizantes/genética , Linfócitos B/imunologia , Linfócitos B/metabolismo , Sítios de Ligação/genética , Anticorpos Amplamente Neutralizantes , Antígenos CD4/genética , Antígenos CD4/imunologia , Antígenos CD4/metabolismo , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/terapia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Filogenia , Polissacarídeos/metabolismo , Homologia de Sequência de Aminoácidos
8.
Nat Commun ; 8(1): 1732, 2017 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-29170366

RESUMO

A strategy for HIV-1 vaccine development is to define envelope (Env) evolution of broadly neutralizing antibodies (bnAbs) in infection and to recreate those events by vaccination. Here, we report host tolerance mechanisms that limit the development of CD4-binding site (CD4bs), HCDR3-binder bnAbs via sequential HIV-1 Env vaccination. Vaccine-induced macaque CD4bs antibodies neutralize 7% of HIV-1 strains, recognize open Env trimers, and accumulate relatively modest somatic mutations. In naive CD4bs, unmutated common ancestor knock-in mice Env+B cell clones develop anergy and partial deletion at the transitional to mature B cell stage, but become Env- upon receptor editing. In comparison with repetitive Env immunizations, sequential Env administration rescue anergic Env+ (non-edited) precursor B cells. Thus, stepwise immunization initiates CD4bs-bnAb responses, but immune tolerance mechanisms restrict their development, suggesting that sequential immunogen-based vaccine regimens will likely need to incorporate strategies to expand bnAb precursor pools.


Assuntos
Anticorpos Neutralizantes/biossíntese , Linfócitos B/imunologia , Anticorpos Anti-HIV/biossíntese , HIV-1/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Linfócitos B/citologia , Sítios de Ligação de Anticorpos , Antígenos CD4/metabolismo , Linhagem da Célula/imunologia , Anergia Clonal , Feminino , Técnicas de Introdução de Genes , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/genética , Humanos , Tolerância Imunológica , Imunização/métodos , Macaca mulatta , Masculino , Camundongos , Camundongos Transgênicos , Modelos Moleculares
9.
Sci Immunol ; 2(7)2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28783671

RESUMO

Induction of broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development. Antibody 10E8, reactive with the distal portion of the membrane-proximal external region (MPER) of HIV-1 gp41, is broadly neutralizing. However, the ontogeny of distal MPER antibodies and the relationship of memory B cell to plasma bnAbs are poorly understood. HIV-1-specific memory B cell flow sorting and proteomic identification of anti-MPER plasma antibodies from an HIV-1-infected individual were used to isolate broadly neutralizing distal MPER bnAbs of the same B cell clonal lineage. Structural analysis demonstrated that antibodies from memory B cells and plasma recognized the envelope gp41 bnAb epitope in a distinct orientation compared with other distal MPER bnAbs. The unmutated common ancestor of this distal MPER bnAb was autoreactive, suggesting lineage immune tolerance control. Construction of chimeric antibodies of memory B cell and plasma antibodies yielded a bnAb that potently neutralized most HIV-1 strains.

10.
J Virol Methods ; 249: 85-93, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28837840

RESUMO

Development of a HIV-1 vaccine is a major global priority. The yellow fever virus (YFV) attenuated vaccine 17D is among the most effective of currently used vaccines. However, the stability of the YFV17D vector when carrying non-flavivirus genes has been problematic. We have constructed and expressed HIV-1 Env in YFV17D with either single transmembrane (STM) or double transmembrane (DTM) YFV E protein domains for the development of anti-HIV antibodies. Here we describe modifications of the YFV17D vector such that HIV-1 Env gp120 is expressed in up to 5 passages in Vero cells. Immunization with recombinant YFV17D vector prime followed by HIV-1 CH505 TF gp120 protein boosts were able to induce neutralizing antibodies for a HIV-1 tier 1 isolate in mice. This modified YFV vector may be a starting point for constructing HIV-1 vaccine candidate priming vectors.


Assuntos
Vacinas contra a AIDS/imunologia , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , HIV-1/imunologia , Vírus da Febre Amarela/genética , Vacinas contra a AIDS/genética , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Chlorocebus aethiops , Vetores Genéticos , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Imunização Secundária , Camundongos , Testes de Neutralização , Vacinas Atenuadas/imunologia , Vacinas de DNA/imunologia , Células Vero
11.
Sci Transl Med ; 9(381)2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28298420

RESUMO

A preventive HIV-1 vaccine should induce HIV-1-specific broadly neutralizing antibodies (bnAbs). However, bnAbs generally require high levels of somatic hypermutation (SHM) to acquire breadth, and current vaccine strategies have not been successful in inducing bnAbs. Because bnAbs directed against a glycosylated site adjacent to the third variable loop (V3) of the HIV-1 envelope protein require limited SHM, the V3-glycan epitope is an attractive vaccine target. By studying the cooperation among multiple V3-glycan B cell lineages and their coevolution with autologous virus throughout 5 years of infection, we identify key events in the ontogeny of a V3-glycan bnAb. Two autologous neutralizing antibody lineages selected for virus escape mutations and consequently allowed initiation and affinity maturation of a V3-glycan bnAb lineage. The nucleotide substitution required to initiate the bnAb lineage occurred at a low-probability site for activation-induced cytidine deaminase activity. Cooperation of B cell lineages and an improbable mutation critical for bnAb activity defined the necessary events leading to breadth in this V3-glycan bnAb lineage. These findings may, in part, explain why initiation of V3-glycan bnAbs is rare, and suggest an immunization strategy for inducing similar V3-glycan bnAbs.


Assuntos
Anticorpos Neutralizantes/metabolismo , HIV-1/imunologia , Polissacarídeos/metabolismo , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Cristalografia por Raios X , Humanos , Masculino , Mutação/genética , Testes de Neutralização , Filogenia , Ligação Proteica , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo
12.
J Immunol ; 198(3): 1047-1055, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011932

RESUMO

In the RV144 gp120 HIV vaccine trial, decreased transmission risk was correlated with Abs that reacted with a linear epitope at a lysine residue at position 169 (K169) in the HIV-1 envelope (Env) V2 region. The K169 V2 response was restricted to Abs bearing Vλ rearrangements that expressed aspartic acid/glutamic acid in CDR L2. The AE.A244 gp120 in AIDSVAX B/E also bound to the unmutated ancestor of a V2-glycan broadly neutralizing Ab, but this Ab type was not induced in the RV144 trial. In this study, we sought to determine whether immunodominance of the V2 linear epitope could be overcome in the absence of human Vλ rearrangements. We immunized IgH- and Igκ-humanized mice with the AE.A244 gp120 Env. In these mice, the V2 Ab response was focused on a linear epitope that did not include K169. V2 Abs were isolated that used the same human VH gene segment as an RV144 V2 Ab but paired with a mouse λ L chain. Structural characterization of one of these V2 Abs revealed how the linear V2 epitope could be engaged, despite the lack of aspartic acid/glutamic acid encoded in the mouse repertoire. Thus, despite the absence of the human Vλ locus in these humanized mice, the dominance of Vλ pairing with human VH for HIV-1 Env V2 recognition resulted in human VH pairing with mouse λ L chains instead of allowing otherwise subdominant V2-glycan broadly neutralizing Abs to develop.


Assuntos
Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/imunologia , Motivos de Aminoácidos , Animais , Anticorpos Neutralizantes/imunologia , Epitopos , Humanos , Cadeias Pesadas de Imunoglobulinas/imunologia , Cadeias lambda de Imunoglobulina/imunologia , Camundongos
13.
JCI Insight ; 1(20): e88522, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27942585

RESUMO

The ALVAC prime/ALVAC + AIDSVAX B/E boost RV144 vaccine trial induced an estimated 31% efficacy in a low-risk cohort where HIV­1 exposures were likely at mucosal surfaces. An immune correlates study demonstrated that antibodies targeting the V2 region and in a secondary analysis antibody-dependent cellular cytotoxicity (ADCC), in the presence of low envelope-specific (Env-specific) IgA, correlated with decreased risk of infection. Thus, understanding the B cell repertoires induced by this vaccine in systemic and mucosal compartments are key to understanding the potential protective mechanisms of this vaccine regimen. We immunized rhesus macaques with the ALVAC/AIDSVAX B/E gp120 vaccine regimen given in RV144, and then gave a boost 6 months later, after which the animals were necropsied. We isolated systemic and intestinal vaccine Env-specific memory B cells. Whereas Env-specific B cell clonal lineages were shared between spleen, draining inguinal, anterior pelvic, posterior pelvic, and periaortic lymph nodes, members of Env­specific B cell clonal lineages were absent in the terminal ileum. Env­specific antibodies were detectable in rectal fluids, suggesting that IgG antibodies present at mucosal sites were likely systemically produced and transported to intestinal mucosal sites.


Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos B/classificação , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/prevenção & controle , Imunidade nas Mucosas , Animais , Anticorpos Anti-HIV/análise , Proteína gp120 do Envelope de HIV/administração & dosagem , Imunização Secundária , Imunoglobulina G/análise , Macaca mulatta
14.
EBioMedicine ; 14: 97-111, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27919754

RESUMO

HIV-1 infection occurs primarily through mucosal transmission. Application of biologically relevant mucosal models can advance understanding of the functional properties of antibodies that mediate HIV protection, thereby guiding antibody-based vaccine development. Here, we employed a human ex vivo vaginal HIV-1 infection model and a rhesus macaque in vivo intrarectal SHIV challenge model to probe the protective capacity of monoclonal broadly-neutralizing (bnAb) and non-neutralizing Abs (nnAbs) that were functionally modified by isotype switching. For human vaginal explants, we developed a replication-competent, secreted NanoLuc reporter virus system and showed that CD4 binding site bnAbs b12 IgG1 and CH31 IgG1 and IgA2 isoforms potently blocked HIV-1JR-CSF and HIV-1Bal26 infection. However, IgG1 and IgA nnAbs, either alone or together, did not inhibit infection despite the presence of FcR-expressing effector cells in the tissue. In macaques, the CH31 IgG1 and IgA2 isoforms infused before high-dose SHIV challenge were completely to partially protective, respectively, while nnAbs (CH54 IgG1 and CH38 mIgA2) were non-protective. Importantly, in both mucosal models IgG1 isotype bnAbs were more protective than the IgA2 isotypes, attributable in part to greater neutralization activity of the IgG1 variants. These findings underscore the importance of potent bnAb induction as a primary goal of HIV-1 vaccine development.


Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Mucosa/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Biomarcadores , Modelos Animais de Doenças , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/genética , Humanos , Imunidade nas Mucosas , Imunofenotipagem , Leucócitos/imunologia , Leucócitos/metabolismo , Macaca mulatta , Mucosa/virologia , Testes de Neutralização , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/imunologia , Vagina/imunologia , Vagina/virologia
15.
EBioMedicine ; 12: 196-207, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27612593

RESUMO

Most HIV-1 vaccines elicit neutralizing antibodies that are active against highly sensitive (tier-1) viruses or rare cases of vaccine-matched neutralization-resistant (tier-2) viruses, but no vaccine has induced antibodies that can broadly neutralize heterologous tier-2 viruses. In this study, we isolated antibodies from an HIV-1-infected individual that targeted the gp41 membrane-proximal external region (MPER) that may have selected single-residue changes in viral variants in the MPER that resulted in neutralization sensitivity to antibodies targeting distal epitopes on the HIV-1 Env. Similarly, a single change in the MPER in a second virus from another infected-individual also conferred enhanced neutralization sensitivity. These gp41 single-residue changes thus transformed tier-2 viruses into tier-1 viruses that were sensitive to vaccine-elicited tier-1 neutralizing antibodies. These data demonstrate that Env amino acid changes within the MPER bnAb epitope of naturally-selected escape viruses can increase neutralization sensitivity to multiple types of neutralizing antibodies, and underscore the critical importance of the MPER for maintaining the integrity of the tier-2 HIV-1 trimer.


Assuntos
Substituição de Aminoácidos , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Domínios e Motivos de Interação entre Proteínas/genética , Domínios e Motivos de Interação entre Proteínas/imunologia , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Bloqueadores/imunologia , Anticorpos Neutralizantes/genética , Variação Antigênica , Modelos Animais de Doenças , Expressão Gênica , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/química , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , Humanos , Imunização , Macaca mulatta , Mutação , Testes de Neutralização
16.
Cell Host Microbe ; 18(3): 354-62, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26355218

RESUMO

The third variable (V3) loop and the CD4 binding site (CD4bs) of the HIV-1 envelope are frequently targeted by neutralizing antibodies (nAbs) in infected individuals. In chronic infection, HIV-1 escape mutants repopulate the plasma, and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3 and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses.


Assuntos
Anticorpos Neutralizantes/imunologia , Linfócitos T CD4-Positivos/virologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Seleção Genética , Ligação Viral , Sítios de Ligação , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Dados de Sequência Molecular , Mutação , RNA Viral/genética , Análise de Sequência de DNA
17.
PLoS Pathog ; 11(8): e1005042, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26237403

RESUMO

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Imunofluorescência , HIV-1/imunologia , Humanos , Mucosa Intestinal/virologia , Macaca mulatta , Conformação Proteica , Reto , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ressonância de Plasmônio de Superfície , Proteínas do Envelope Viral/química
18.
J Clin Invest ; 125(7): 2702-6, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26053661

RESUMO

Despite the wide availability of antiretroviral drugs, more than 250,000 infants are vertically infected with HIV-1 annually, emphasizing the need for additional interventions to eliminate pediatric HIV-1 infections. Here, we aimed to define humoral immune correlates of risk of mother-to-child transmission (MTCT) of HIV-1, including responses associated with protection in the RV144 vaccine trial. Eighty-three untreated, HIV-1-transmitting mothers and 165 propensity score-matched nontransmitting mothers were selected from the Women and Infants Transmission Study (WITS) of US nonbreastfeeding, HIV-1-infected mothers. In a multivariable logistic regression model, the magnitude of the maternal IgG responses specific for the third variable loop (V3) of the HIV-1 envelope was predictive of a reduced risk of MTCT. Neutralizing Ab responses against easy-to-neutralize (tier 1) HIV-1 strains also predicted a reduced risk of peripartum transmission in secondary analyses. Moreover, recombinant maternal V3-specific IgG mAbs mediated neutralization of autologous HIV-1 isolates. Thus, common V3-specific Ab responses in maternal plasma predicted a reduced risk of MTCT and mediated autologous virus neutralization, suggesting that boosting these maternal Ab responses may further reduce HIV-1 MTCT.


Assuntos
Anticorpos Anti-HIV/sangue , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/transmissão , HIV-1/imunologia , Fragmentos de Peptídeos/imunologia , Complicações Infecciosas na Gravidez/imunologia , Vacinas contra a AIDS/farmacologia , Anticorpos Neutralizantes/sangue , Especificidade de Anticorpos , Antígenos Virais , Estudos de Coortes , Feminino , Infecções por HIV/complicações , Humanos , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Modelos Logísticos , Análise Multivariada , Gravidez , Fatores de Risco
19.
Cell ; 158(3): 481-91, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25065977

RESUMO

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.


Assuntos
Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/fisiologia , Sequência de Aminoácidos , Linfócitos B/imunologia , Evasão da Resposta Imune , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Alinhamento de Sequência , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
20.
PLoS One ; 9(3): e90725, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24614505

RESUMO

B-cell chronic lymphocytic leukemia (B-CLL) patients expressing unmutated immunoglobulin heavy variable regions (IGHVs) use the IGHV1-69 B cell receptor (BCR) in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s) (≥21 aa). IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54) of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54) allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.


Assuntos
Anticorpos Antineoplásicos/imunologia , Bactérias/imunologia , Reações Cruzadas/imunologia , Antígenos HIV/imunologia , Antígenos da Hepatite C/imunologia , Intestinos/microbiologia , Leucemia Linfocítica Crônica de Células B/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Alelos , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Linhagem Celular Tumoral , Antígenos HIV/química , Infecções por HIV/imunologia , HIV-1/imunologia , Hepacivirus/imunologia , Humanos , Hibridomas/imunologia , Cadeias Pesadas de Imunoglobulinas , Região Variável de Imunoglobulina , Dados de Sequência Molecular , Paraproteínas/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Simbiose , Resultado do Tratamento
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