Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nature ; 519(7541): 87-91, 2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25707797

RESUMO

Long-term in vivo expression of a broad and potent entry inhibitor could circumvent the need for a conventional vaccine for HIV-1. Adeno-associated virus (AAV) vectors can stably express HIV-1 broadly neutralizing antibodies (bNAbs). However, even the best bNAbs neutralize 10-50% of HIV-1 isolates inefficiently (80% inhibitory concentration (IC80) > 5 µg ml(-1)), suggesting that high concentrations of these antibodies would be necessary to achieve general protection. Here we show that eCD4-Ig, a fusion of CD4-Ig with a small CCR5-mimetic sulfopeptide, binds avidly and cooperatively to the HIV-1 envelope glycoprotein (Env) and is more potent than the best bNAbs (geometric mean half-maximum inhibitory concentration (IC50) < 0.05 µg ml(-1)). Because eCD4-Ig binds only conserved regions of Env, it is also much broader than any bNAb. For example, eCD4-Ig efficiently neutralized 100% of a diverse panel of neutralization-resistant HIV-1, HIV-2 and simian immunodeficiency virus isolates, including a comprehensive set of isolates resistant to the CD4-binding site bNAbs VRC01, NIH45-46 and 3BNC117. Rhesus macaques inoculated with an AAV vector stably expressed 17-77 µg ml(-1) of fully functional rhesus eCD4-Ig for more than 40 weeks, and these macaques were protected from several infectious challenges with SHIV-AD8. Rhesus eCD4-Ig was also markedly less immunogenic than rhesus forms of four well-characterized bNAbs. Our data suggest that AAV-delivered eCD4-Ig can function like an effective HIV-1 vaccine.


Assuntos
Antígenos CD4/imunologia , Dependovirus/genética , Imunoglobulinas/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Internalização do Vírus , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Antagonistas dos Receptores CCR5/imunologia , Antígenos CD4/genética , Feminino , Terapia Genética , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , HIV-2/imunologia , Imunoglobulinas/genética , Macaca mulatta , Masculino , Testes de Neutralização , Receptores CCR5/metabolismo , Síndrome de Imunodeficiência Adquirida dos Símios/virologia
2.
J Virol ; 86(22): 12417-21, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22933279

RESUMO

A tyrosine-sulfated CCR5-mimetic peptide, CCR5mim1, inhibits HIV-1 infection more efficiently than sulfopeptides based on the CCR5 amino terminus. Here we characterized sulfopeptide chimeras of CCR5mim1 and the heavy-chain CDR3 of the antibody PG16. Two chimeras bound a range of envelope glycoproteins and neutralized HIV-1 more efficiently than CCR5mim1. An immunoadhesin form of one of these, CCR5mim2-Ig, synergized with CD4-Ig to neutralize HIV-1. These sulfopeptides are among the broadest and most potent CCR5-mimetic peptides described to date.


Assuntos
Infecções por HIV/metabolismo , HIV-1/metabolismo , Receptores CCR5/metabolismo , Anticorpos Neutralizantes/química , Linfócitos T CD4-Positivos/citologia , Epitopos/química , Glicoproteínas/química , Células HEK293 , Humanos , Testes de Neutralização , Peptídeos/química , Ligação Proteica , Estrutura Terciária de Proteína , Receptores CCR5/química
3.
J Virol ; 85(15): 7563-71, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21613393

RESUMO

The HIV-1 envelope glycoprotein is a trimeric complex of heterodimers composed of a surface glycoprotein, gp120, and a transmembrane component, gp41. The association of this complex with CD4 stabilizes the coreceptor-binding site of gp120 and promotes the exposure of the gp41 helical region 1 (HR1). Here, we show that a 15-amino-acid peptide mimetic of the HIV-1 coreceptor CCR5 fused to a dimeric antibody Fc domain (CCR5mim-Ig) bound two gp120 molecules per envelope glycoprotein complex and by itself promoted HR1 exposure. CCR5mim-Ig also stabilized the association of a CD4-mimetic peptide with the envelope glycoprotein. A fusion of the CD4- and CCR5-mimetic peptides, DM1, bound gp120 and neutralized R5, R5X4, and X4 HIV-1 isolates comparably to CD4, and they did so markedly more efficiently than either peptide alone. Our data indicate that the potency of DM1-Ig derives from its avidity for the HIV-1 envelope glycoprotein trimer and from the bidirectional induction of its receptor-mimetic components. DM1 has significant advantages over other inhibitors that target both coreceptor and CD4-binding sites, and it may serve as a lead for a new class of HIV-1 inhibitor peptides.


Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/metabolismo , Mimetismo Molecular , Receptores CCR5/metabolismo , Sulfatos/metabolismo , Tirosina/metabolismo , Linhagem Celular , Citometria de Fluxo , Proteína gp120 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/química , HIV-1 , Humanos , Modelos Moleculares , Conformação Proteica , Receptores CCR5/química
4.
Proc Natl Acad Sci U S A ; 105(7): 2664-9, 2008 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-18268337

RESUMO

Transferrin receptor 1 (TfR1) is a cellular receptor for the New World hemorrhagic fever arenaviruses Machupo (MACV), Junín (JUNV), and Guanarito (GTOV). Each of these viruses is specifically adapted to a distinct rodent host species, but all cause human disease. Here we compare the ability of these viruses to use various mammalian transferrin receptor 1 (TfR1) orthologs, including those of the South American rodents that serve as reservoirs for MACV, JUNV, and GTOV (Calomys callosus, Calomys musculinus, and Zygodontomys brevicauda, respectively). Retroviruses pseudotyped with MACV and JUNV but not GTOV glycoproteins (GPs) efficiently used C. callosus TfR1, whereas only JUNV GP could use C. musculinus TfR1. All three viruses efficiently used Z. brevicauda TfR1. TfR1 orthologs from related rodents, including house mouse (Mus musculus) and rat (Rattus norvegicus), did not support entry of these viruses. In contrast, these viruses efficiently used human and domestic cat TfR1 orthologs. We further show that a local region of the human TfR1 apical domain, including tyrosine 211, determined the efficiency with which MACV, JUNV, and GTOV used various TfR1 orthologs. Our data show that these New World arenaviruses are specifically adapted to the TfR1 orthologs of their respective rodent hosts and identify key commonalities between these orthologs and human TfR1 necessary for efficient transmission of these viruses to humans.


Assuntos
Infecções por Arenaviridae/transmissão , Arenavirus do Novo Mundo/fisiologia , Receptores da Transferrina/metabolismo , Sequência de Aminoácidos , Animais , Infecções por Arenaviridae/genética , Infecções por Arenaviridae/metabolismo , Sítios de Ligação , Glicosilação , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Ligação Proteica , Estrutura Quaternária de Proteína , Receptores da Transferrina/química , Receptores da Transferrina/classificação , Receptores da Transferrina/genética , Alinhamento de Sequência , Homologia Estrutural de Proteína , Tirosina/genética , Tirosina/metabolismo , Internalização do Vírus
5.
J Biol Chem ; 281(39): 28529-35, 2006 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-16849323

RESUMO

Sulfated tyrosines at the amino terminus of the principal HIV-1 coreceptor CCR5 play a critical role in its ability to bind the HIV-1 envelope glycoprotein gp120 and mediate HIV-1 entry. Human antibodies that recognize the CCR5-binding region of gp120 are also modified by tyrosine sulfation, which is necessary for their ability to neutralize HIV-1. Here we demonstrate that a sulfated peptide derived from the CDR3 region of one of these antibodies, E51, can efficiently bind gp120. Association of this peptide, pE51, with gp120 requires tyrosine sulfation and is enhanced by, but not dependent on, CD4. Alteration of any of four pE51 tyrosines, or alteration of gp120 residues 420, 421, or 422, critical for association with CCR5, prevents gp120 association with pE51. pE51 neutralizes HIV-1 more effectively than peptides based on the CCR5 amino terminus and may be useful as a fusion partner with other protein inhibitors of HIV-1 entry. Our data provide further insight into the association of the CCR5 amino terminus with gp120, show that a conserved, sulfate-binding region of gp120 is accessible to inhibitors in the absence of CD4, and suggest that soluble mimetics of CCR5 can be more effective than previously appreciated.


Assuntos
Anticorpos Anti-HIV/química , Proteína gp120 do Envelope de HIV/química , HIV-1/química , Receptores CCR5/química , Tirosina/química , Sequência de Aminoácidos , Linhagem Celular , Relação Dose-Resposta a Droga , Infecções por HIV , Humanos , Dados de Sequência Molecular , Peptídeos/química , Ligação Proteica , Estrutura Terciária de Proteína , Sulfatos/química
6.
J Virol ; 78(19): 10628-35, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15367630

RESUMO

Infection of receptor-bearing cells by coronaviruses is mediated by their spike (S) proteins. The coronavirus (SARS-CoV) that causes severe acute respiratory syndrome (SARS) infects cells expressing the receptor angiotensin-converting enzyme 2 (ACE2). Here we show that codon optimization of the SARS-CoV S-protein gene substantially enhanced S-protein expression. We also found that two retroviruses, simian immunodeficiency virus (SIV) and murine leukemia virus, both expressing green fluorescent protein and pseudotyped with SARS-CoV S protein or S-protein variants, efficiently infected HEK293T cells stably expressing ACE2. Infection mediated by an S-protein variant whose cytoplasmic domain had been truncated and altered to include a fragment of the cytoplasmic tail of the human immunodeficiency virus type 1 envelope glycoprotein was, in both cases, substantially more efficient than that mediated by wild-type S protein. Using S-protein-pseudotyped SIV, we found that the enzymatic activity of ACE2 made no contribution to S-protein-mediated infection. Finally, we show that a soluble and catalytically inactive form of ACE2 potently blocked infection by S-protein-pseudotyped retrovirus and by SARS-CoV. These results permit studies of SARS-CoV entry inhibitors without the use of live virus and suggest a candidate therapy for SARS.


Assuntos
Carboxipeptidases/metabolismo , Vírus da Leucemia Murina/fisiologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Vírus da Imunodeficiência Símia/fisiologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Animais , Carboxipeptidases/genética , Linhagem Celular , HIV-1/genética , Humanos , Vírus da Leucemia Murina/genética , Vírus da Leucemia Murina/metabolismo , Dados de Sequência Molecular , Peptidil Dipeptidase A , Receptores Virais/metabolismo , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/metabolismo , Glicoproteína da Espícula de Coronavírus , Vírion/química , Vírion/metabolismo , Replicação Viral
7.
Cell ; 114(2): 161-70, 2003 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-12887918

RESUMO

Sulfated tyrosines at the amino terminus of the principal HIV-1 coreceptor CCR5 play a critical role in its ability to bind the HIV-1 envelope glycoprotein gp120 and mediate HIV-1 infection. Here, we show that a number of human antibodies directed against gp120 are tyrosine sulfated at their antigen binding sites. Like that of CCR5, antibody association with gp120 is dependent on sulfate moieties, enhanced by CD4, and inhibited by sulfated CCR5-derived peptides. Most of these antibodies preferentially associate with gp120 molecules of CCR5-utilizing (R5) isolates and neutralize primary R5 isolates more efficiently than laboratory-adapted isolates. These studies identify a distinct subset of CD4-induced HIV-1 neutralizing antibodies that closely emulate CCR5 and demonstrate that tyrosine sulfation can contribute to the potency and diversity of the human humoral response.


Assuntos
Anticorpos Monoclonais/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/metabolismo , Receptores CCR5/metabolismo , Sulfatos/metabolismo , Tirosina/metabolismo , Sequência de Aminoácidos , Linfócitos B/metabolismo , Sítios de Ligação , Antígenos CD4/química , Antígenos CD4/metabolismo , Linhagem Celular , Humanos , Hibridomas/metabolismo , Modelos Biológicos , Dados de Sequência Molecular , Receptores CCR5/química , Relação Estrutura-Atividade
8.
J Virol ; 76(13): 6857-62, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12050401

RESUMO

Nef enhances the serine phosphorylation of the human immunodeficiency virus type 1 matrix (MA) protein, which suggests that MA may be a functional target of Nef. Using mutants that remain infectious despite the absence of most or all of MA, we show in the present study that the ability of Nef to enhance virus infectivity is not compromised even if MA is entirely replaced by a heterologous lipid anchor.


Assuntos
Deleção de Genes , Produtos do Gene nef/metabolismo , HIV-1/patogenicidade , Proteínas da Matriz Viral/genética , Linhagem Celular , HIV-1/fisiologia , Humanos , Fosforilação , Linfócitos T/virologia , Proteínas da Matriz Viral/metabolismo , Produtos do Gene nef do Vírus da Imunodeficiência Humana
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...