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2.
Cell Host Microbe ; 25(1): 59-72.e8, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30629920

RESUMO

Eliciting HIV-1-specific broadly neutralizing antibodies (bNAbs) remains a challenge for vaccine development, and the potential of passively delivered bNAbs for prophylaxis and therapeutics is being explored. We used neutralization data from four large virus panels to comprehensively map viral signatures associated with bNAb sensitivity, including amino acids, hypervariable region characteristics, and clade effects across four different classes of bNAbs. The bNAb signatures defined for the variable loop 2 (V2) epitope region of HIV-1 Env were then employed to inform immunogen design in a proof-of-concept exploration of signature-based epitope targeted (SET) vaccines. V2 bNAb signature-guided mutations were introduced into Env 459C to create a trivalent vaccine, and immunization of guinea pigs with V2-SET vaccines resulted in increased breadth of NAb responses compared with Env 459C alone. These data demonstrate that bNAb signatures can be utilized to engineer HIV-1 Env vaccine immunogens capable of eliciting antibody responses with greater neutralization breadth.


Assuntos
Anticorpos Neutralizantes/imunologia , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Vacinas , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/uso terapêutico , Formação de Anticorpos , Modelos Animais de Doenças , Epitopos/genética , Feminino , Cobaias , Células HEK293 , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , Humanos , Imunização , Concentração Inibidora 50 , Modelos Moleculares , Mutação , Fragmentos de Peptídeos/imunologia , Ligação Proteica , Vacinação , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
3.
Cell ; 170(4): 637-648.e10, 2017 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-28757252

RESUMO

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/virologia
4.
Nature ; 535(7613): 556-60, 2016 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-27338952

RESUMO

Interruption of combination antiretroviral therapy in HIV-1-infected individuals leads to rapid viral rebound. Here we report the results of a phase IIa open label clinical trial evaluating 3BNC117,a broad and potent neutralizing antibody against the CD4 binding site of the HIV-1 Env protein, during analytical treatment interruption in 13 HIV-1-infected individuals. Participants with 3BNC117-sensitive virus outgrowth cultures were enrolled. Results show that two or four 30 mg kg(-1) 3BNC117 infusions,separated by 3 or 2 weeks, respectively, are generally well tolerated.Infusions are associated with a delay in viral rebound of 5-9 weeks after two infusions, and up to 19 weeks after four infusions, or an average of 6.7 and 9.9 weeks, respectively, compared with 2.6 weeks for historical controls (P < 0.00001). Rebound viruses arise predominantly from a single provirus. In most individuals,emerging viruses show increased resistance, indicating escape.However, 30% of participants remained suppressed until antibody concentrations waned below 20 µg ml(-1), and the viruses emerging in all but one of these individuals showed no apparent resistance to 3BCN117, suggesting failure to escape over a period of 9-19 weeks.We conclude that the administration of 3BNC117 exerts strong selective pressure on HIV-1 emerging from latent reservoirs during analytical treatment interruption in humans.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/crescimento & desenvolvimento , HIV-1/imunologia , Adolescente , Adulto , Idoso , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/uso terapêutico , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/imunologia , Antígenos CD4/metabolismo , Reservatórios de Doenças/virologia , Esquema de Medicação , Feminino , Anticorpos Anti-HIV/administração & dosagem , Anticorpos Anti-HIV/uso terapêutico , Proteína gp160 do Envelope de HIV/antagonistas & inibidores , Proteína gp160 do Envelope de HIV/química , Proteína gp160 do Envelope de HIV/imunologia , Proteína gp160 do Envelope de HIV/metabolismo , Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , Estudo Historicamente Controlado , Humanos , Masculino , Pessoa de Meia-Idade , Provírus/efeitos dos fármacos , Provírus/crescimento & desenvolvimento , Provírus/imunologia , Fatores de Tempo , Distribuição Tecidual , Carga Viral/efeitos dos fármacos , Carga Viral/imunologia , Adulto Jovem
6.
Elife ; 52016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26997349

RESUMO

Efforts to elicit broadly neutralizing antibodies (bNAbs) against HIV-1 require understanding germline bNAb recognition of HIV-1 envelope glycoprotein (Env). The VRC01-class bNAb family derived from the VH1-2*02 germline allele arose in multiple HIV-1-infected donors, yet targets the CD4-binding site on Env with common interactions. Modified forms of the 426c Env that activate germline-reverted B cell receptors are candidate immunogens for eliciting VRC01-class bNAbs. We present structures of germline-reverted VRC01-class bNAbs alone and complexed with 426c-based gp120 immunogens. Germline bNAb-426c gp120 complexes showed preservation of VRC01-class signature residues and gp120 contacts, but detectably different binding modes compared to mature bNAb-gp120 complexes. Unlike typical antibody-antigen interactions, VRC01-class germline antibodies exhibited preformed antigen-binding conformations for recognizing immunogens. Affinity maturation introduced substitutions increasing induced-fit recognition and electropositivity, potentially to accommodate negatively-charged complex-type N-glycans on gp120. These results provide general principles relevant to the unusual evolution of VRC01-class bNAbs and guidelines for structure-based immunogen design.


Assuntos
Anticorpos Neutralizantes/química , Anticorpos Anti-HIV/química , Antígenos HIV/química , Proteína gp120 do Envelope de HIV/química , HIV-1/química , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/metabolismo , Cristalografia por Raios X , Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/metabolismo , Antígenos HIV/imunologia , Antígenos HIV/metabolismo , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/imunologia , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica
7.
PLoS Pathog ; 11(10): e1005238, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26516768

RESUMO

The CD4 binding site (CD4bs) on the envelope glycoprotein is a major site of vulnerability that is conserved among different HIV-1 isolates. Many broadly neutralizing antibodies (bNAbs) to the CD4bs belong to the VRC01 class, sharing highly restricted origins, recognition mechanisms and viral escape pathways. We sought to isolate new anti-CD4bs bNAbs with different origins and mechanisms of action. Using a gp120 2CC core as bait, we isolated antibodies encoded by IGVH3-21 and IGVL3-1 genes with long CDRH3s that depend on the presence of the N-linked glycan at position-276 for activity. This binding mode is similar to the previously identified antibody HJ16, however the new antibodies identified herein are more potent and broad. The most potent variant, 179NC75, had a geometric mean IC80 value of 0.42 µg/ml against 120 Tier-2 HIV-1 pseudoviruses in the TZM.bl assay. Although this group of CD4bs glycan-dependent antibodies can be broadly and potently neutralizing in vitro, their in vivo activity has not been tested to date. Here, we report that 179NC75 is highly active when administered to HIV-1-infected humanized mice, where it selects for escape variants that lack a glycan site at position-276. The same glycan was absent from the virus isolated from the 179NC75 donor, implying that the antibody also exerts selection pressure in humans.


Assuntos
Anticorpos Neutralizantes/imunologia , Antígenos CD4/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Polissacarídeos/química , Animais , Sítios de Ligação , Células HEK293 , Anticorpos Anti-HIV/química , Humanos , Camundongos
8.
Cell ; 161(6): 1280-92, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-26004070

RESUMO

The site on the HIV-1 gp120 glycoprotein that binds the CD4 receptor is recognized by broadly reactive antibodies, several of which neutralize over 90% of HIV-1 strains. To understand how antibodies achieve such neutralization, we isolated CD4-binding-site (CD4bs) antibodies and analyzed 16 co-crystal structures -8 determined here- of CD4bs antibodies from 14 donors. The 16 antibodies segregated by recognition mode and developmental ontogeny into two types: CDR H3-dominated and VH-gene-restricted. Both could achieve greater than 80% neutralization breadth, and both could develop in the same donor. Although paratope chemistries differed, all 16 gp120-CD4bs antibody complexes showed geometric similarity, with antibody-neutralization breadth correlating with antibody-angle of approach relative to the most effective antibody of each type. The repertoire for effective recognition of the CD4 supersite thus comprises antibodies with distinct paratopes arrayed about two optimal geometric orientations, one achieved by CDR H3 ontogenies and the other achieved by VH-gene-restricted ontogenies.


Assuntos
Anticorpos Neutralizantes/química , Anticorpos Antivirais/química , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/fisiologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Linfócitos B/imunologia , Antígenos CD4/metabolismo , Regiões Determinantes de Complementaridade , Epitopos de Linfócito B , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de Sequência
9.
Nature ; 522(7557): 487-91, 2015 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-25855300

RESUMO

HIV-1 immunotherapy with a combination of first generation monoclonal antibodies was largely ineffective in pre-clinical and clinical settings and was therefore abandoned. However, recently developed single-cell-based antibody cloning methods have uncovered a new generation of far more potent broadly neutralizing antibodies to HIV-1 (refs 4, 5). These antibodies can prevent infection and suppress viraemia in humanized mice and nonhuman primates, but their potential for human HIV-1 immunotherapy has not been evaluated. Here we report the results of a first-in-man dose escalation phase 1 clinical trial of 3BNC117, a potent human CD4 binding site antibody, in uninfected and HIV-1-infected individuals. 3BNC117 infusion was well tolerated and demonstrated favourable pharmacokinetics. A single 30 mg kg(-1) infusion of 3BNC117 reduced the viral load in HIV-1-infected individuals by 0.8-2.5 log10 and viraemia remained significantly reduced for 28 days. Emergence of resistant viral strains was variable, with some individuals remaining sensitive to 3BNC117 for a period of 28 days. We conclude that, as a single agent, 3BNC117 is safe and effective in reducing HIV-1 viraemia, and that immunotherapy should be explored as a new modality for HIV-1 prevention, therapy and cure.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/terapia , HIV-1/imunologia , Carga Viral/imunologia , Viremia/terapia , Adulto , Sequência de Aminoácidos , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/efeitos adversos , Anticorpos Neutralizantes/farmacologia , Anticorpos Neutralizantes/uso terapêutico , Sítios de Ligação , Antígenos CD4/metabolismo , Estudos de Casos e Controles , Evolução Molecular , Feminino , Anticorpos Anti-HIV/administração & dosagem , Anticorpos Anti-HIV/efeitos adversos , Anticorpos Anti-HIV/farmacologia , Anticorpos Anti-HIV/uso terapêutico , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/química , HIV-1/efeitos dos fármacos , Humanos , Imunização Passiva/métodos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fatores de Tempo , Carga Viral/efeitos dos fármacos , Viremia/imunologia , Viremia/virologia , Adulto Jovem
10.
J Immunol Methods ; 418: 61-5, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25667013

RESUMO

Isolation and characterization of anti HIV-1 broadly neutralizing antibodies (bNAbs) have elucidated new epitopes and sites of viral vulnerability. Anti-HIV-1 bNAbs typically show high levels of somatic mutations in their variable region genes. This feature potentially limits antibody identification, since the mutated antibody sequences are no longer complimentary to primers designed based on germline antibody sequences. Here we report a new set of primers for Igλ light chains that aligns to the 5' end of the leader sequence and is highly efficient for the amplification of antibodies that contain mutations and deletions in the 5' end of human Igλ.


Assuntos
Infecções por HIV/genética , Infecções por HIV/imunologia , Cadeias lambda de Imunoglobulina/genética , Cadeias lambda de Imunoglobulina/imunologia , Mutagênese/genética , Mutação/genética , Citometria de Fluxo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/virologia
12.
Science ; 346(6215): 1380-1383, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25504724

RESUMO

Some HIV-infected individuals develop broadly neutralizing antibodies (bNAbs), whereas most develop antibodies that neutralize only a narrow range of viruses (nNAbs). bNAbs, but not nNAbs, protect animals from experimental infection and are likely a key component of an effective vaccine. nNAbs and bNAbs target the same regions of the viral envelope glycoprotein (Env), but for reasons that remain unclear only nNAbs are elicited by Env immunization. We show that in contrast to germline-reverted (gl) bNAbs, glnNAbs recognized diverse recombinant Envs. Moreover, owing to binding affinity differences, nNAb B cell progenitors had an advantage in becoming activated and internalizing Env compared with bNAb B cell progenitors. We then identified an Env modification strategy that minimized the activation of nNAb B cells targeting epitopes that overlap those of bNAbs.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/imunologia , Afinidade de Anticorpos , Linfócitos B/imunologia , Ligação Competitiva , Epitopos/imunologia , Anticorpos Anti-HIV/genética , Humanos , Ativação Linfocitária , Modelos Moleculares , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Proteínas Recombinantes/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
13.
Nat Methods ; 11(12): 1253-60, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25362362

RESUMO

Nanobodies are single-domain antibodies derived from the variable regions of Camelidae atypical immunoglobulins. They show promise as high-affinity reagents for research, diagnostics and therapeutics owing to their high specificity, small size (∼15 kDa) and straightforward bacterial expression. However, identification of repertoires with sufficiently high affinity has proven time consuming and difficult, hampering nanobody implementation. Our approach generates large repertoires of readily expressible recombinant nanobodies with high affinities and specificities against a given antigen. We demonstrate the efficacy of this approach through the production of large repertoires of nanobodies against two antigens, GFP and mCherry, with Kd values into the subnanomolar range. After mapping diverse epitopes on GFP, we were also able to design ultrahigh-affinity dimeric nanobodies with Kd values as low as ∼30 pM. The approach presented here is well suited for the routine production of high-affinity capture reagents for various biomedical applications.


Assuntos
Epitopos/imunologia , Proteínas de Fluorescência Verde/imunologia , Proteínas Luminescentes/imunologia , Proteínas Recombinantes/isolamento & purificação , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/isolamento & purificação , Animais , Camelídeos Americanos , Epitopos/genética , Epitopos/metabolismo , Biblioteca Gênica , Proteínas de Fluorescência Verde/metabolismo , Imunização , Proteínas Luminescentes/metabolismo , Linfócitos/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Anticorpos de Domínio Único/genética , Anticorpos de Domínio Único/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Cell Rep ; 7(3): 785-95, 2014 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-24767986

RESUMO

Broadly neutralizing antibodies (bNAbs) to HIV-1 envelope glycoprotein (Env) can prevent infection in animal models. Characterized bNAb targets, although key to vaccine and therapeutic strategies, are currently limited. We defined a new site of vulnerability by solving structures of bNAb 8ANC195 complexed with monomeric gp120 by X-ray crystallography and trimeric Env by electron microscopy. The site includes portions of gp41 and N-linked glycans adjacent to the CD4-binding site on gp120, making 8ANC195 the first donor-derived anti-HIV-1 bNAb with an epitope spanning both Env subunits. Rather than penetrating the glycan shield by using a single variable-region CDR loop, 8ANC195 inserted its entire heavy-chain variable domain into a gap to form a large interface with gp120 glycans and regions of the gp120 inner domain not contacted by other bNAbs. By isolating additional 8ANC195 clonal variants, we identified a more potent variant, which may be valuable for therapeutic approaches using bNAb combinations with nonoverlapping epitopes.


Assuntos
Anticorpos Neutralizantes/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/metabolismo , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Epitopos/química , Epitopos/imunologia , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/genética , Humanos , Simulação de Dinâmica Molecular , Polissacarídeos/química , Polissacarídeos/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo
15.
Cell ; 156(4): 633-48, 2014 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-24529371

RESUMO

Despite 30 years of effort, there is no effective vaccine for HIV-1. However, antibodies can prevent HIV-1 infection in humanized mice and macaques when passively transferred. New single-cell-based methods have uncovered many broad and potent donor-derived antibodies, and structural studies have revealed the molecular bases for their activities. The new data suggest why such antibodies are difficult to elicit and inform HIV-1 vaccine development efforts. In addition to protecting against infection, the newly identified antibodies can suppress active infections in mice and macaques, suggesting they could be valuable additions to anti-HIV-1 therapies and to strategies to eradicate HIV-1 infection.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1 , Vacinas contra a AIDS/uso terapêutico , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/química , Humanos , Imunoterapia , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
16.
J Exp Med ; 210(13): 2813-21, 2013 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-24277152

RESUMO

The neutralizing activity of anti-HIV-1 antibodies is typically measured in assays where cell-free virions enter reporter cell lines. However, HIV-1 cell to cell transmission is a major mechanism of viral spread, and the effect of the recently described broadly neutralizing antibodies (bNAbs) on this mode of transmission remains unknown. Here we identify a subset of bNAbs that inhibit both cell-free and cell-mediated infection in primary CD4(+) lymphocytes. These antibodies target either the CD4-binding site (NIH45-46 and 3BNC60) or the glycan/V3 loop (10-1074 and PGT121) on HIV-1 gp120 and act at low concentrations by inhibiting multiple steps of viral cell to cell transmission. These antibodies accumulate at virological synapses and impair the clustering and fusion of infected and target cells and the transfer of viral material to uninfected T cells. In addition, they block viral cell to cell transmission to plasmacytoid DCs and thereby interfere with type-I IFN production. Thus, only a subset of bNAbs can efficiently prevent HIV-1 cell to cell transmission, and this property should be considered an important characteristic defining antibody potency for therapeutic or prophylactic antiviral strategies.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV/fisiologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Técnicas de Cocultura , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células HEK293 , Células HeLa , Humanos , Concentração Inibidora 50 , Microscopia de Fluorescência , Fatores de Tempo , Vírion/fisiologia
17.
J Immunol Methods ; 397(1-2): 47-54, 2013 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-24041474

RESUMO

Significant efforts have been made to identify HIV-1 neutralizing antibodies because they are considered to be critical to the design of an effective HIV-1 vaccine. Although soluble HIV-1 envelope proteins can be used for this purpose, these reagents differ from membrane-anchored HIV-1 envelope spike in a number of important ways and display only a subset of its native epitopes. Consistent with this, some broadly neutralizing antibodies preferentially bind cell surface-expressed HIV-1 envelope, but not the soluble protein. Here we report the details of a new method for isolating anti-HIV-1 specific B cells based on capturing cells that produce antibodies to cell surface-expressed gp160Δc(BaL). While this method is far less efficient than sorting with soluble envelope proteins, it isolated broadly neutralizing anti-HIV-1 antibodies that bind cell surface-expressed gp160Δc(BaL) but not soluble envelope proteins.


Assuntos
Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/isolamento & purificação , Proteína gp160 do Envelope de HIV/imunologia , Proteína gp160 do Envelope de HIV/metabolismo , HIV-1/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linhagem Celular , Células HEK293 , Proteína gp160 do Envelope de HIV/biossíntese , Humanos
18.
Science ; 341(6151): 1199-204, 2013 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-24031012

RESUMO

Despite 30 years of study, there is no HIV-1 vaccine and, until recently, there was little hope for a protective immunization. Renewed optimism in this area of research comes in part from the results of a recent vaccine trial and the use of single-cell antibody-cloning techniques that uncovered naturally arising, broad and potent HIV-1-neutralizing antibodies (bNAbs). These antibodies can protect against infection and suppress established HIV-1 infection in animal models. The finding that these antibodies develop in a fraction of infected individuals supports the idea that new approaches to vaccination might be developed by adapting the natural immune strategies or by structure-based immunogen design. Moreover, the success of passive immunotherapy in small-animal models suggests that bNAbs may become a valuable addition to the armamentarium of drugs that work against HIV-1.


Assuntos
Vacinas contra a AIDS/uso terapêutico , Síndrome de Imunodeficiência Adquirida/terapia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/terapia , HIV-1/imunologia , Síndrome de Imunodeficiência Adquirida/prevenção & controle , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/genética , Anticorpos Anti-HIV/biossíntese , Anticorpos Anti-HIV/genética , Humanos , Imunoterapia , Proteínas do Envelope Viral/imunologia
19.
Immunity ; 39(2): 245-58, 2013 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-23911655

RESUMO

Antibodies of the VRC01 class neutralize HIV-1, arise in diverse HIV-1-infected donors, and are potential templates for an effective HIV-1 vaccine. However, the stochastic processes that generate repertoires in each individual of >10(12) antibodies make elicitation of specific antibodies uncertain. Here we determine the ontogeny of the VRC01 class by crystallography and next-generation sequencing. Despite antibody-sequence differences exceeding 50%, antibody-gp120 cocrystal structures reveal VRC01-class recognition to be remarkably similar. B cell transcripts indicate that VRC01-class antibodies require few specific genetic elements, suggesting that naive-B cells with VRC01-class features are generated regularly by recombination. Virtually all of these fail to mature, however, with only a few-likely one-ancestor B cell expanding to form a VRC01-class lineage in each donor. Developmental similarities in multiple donors thus reveal the generation of VRC01-class antibodies to be reproducible in principle, thereby providing a framework for attempts to elicit similar antibodies in the general population.


Assuntos
Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Sequência de Bases , Cristalografia por Raios X , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Humanos , Leucócitos Mononucleares , Dados de Sequência Molecular , Análise de Sequência de DNA
20.
Cell ; 153(1): 126-38, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23540694

RESUMO

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 Drogas , 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 Sequência
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