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1.
Nature ; 505(7484): 502-8, 2014 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-24352234

RESUMEN

A major challenge for the development of a highly effective AIDS vaccine is the identification of mechanisms of protective immunity. To address this question, we used a nonhuman primate challenge model with simian immunodeficiency virus (SIV). We show that antibodies to the SIV envelope are necessary and sufficient to prevent infection. Moreover, sequencing of viruses from breakthrough infections revealed selective pressure against neutralization-sensitive viruses; we identified a two-amino-acid signature that alters antigenicity and confers neutralization resistance. A similar signature confers resistance of human immunodeficiency virus (HIV)-1 to neutralization by monoclonal antibodies against variable regions 1 and 2 (V1V2), suggesting that SIV and HIV share a fundamental mechanism of immune escape from vaccine-elicited or naturally elicited antibodies. These analyses provide insight into the limited efficacy seen in HIV vaccine trials.


Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/prevención & control , Infecciones por VIH/virología , VIH-1/inmunología , Vacunas contra el SIDAS/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Neutralizantes/inmunología , Susceptibilidad a Enfermedades/inmunología , Femenino , Efecto Fundador , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/química , Humanos , Evasión Inmune/inmunología , Macaca mulatta , Masculino , Datos de Secuencia Molecular , Filogenia , Riesgo , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/química , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/fisiología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
2.
J Virol ; 89(12): 6462-80, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25855741

RESUMEN

UNLABELLED: An effective human immunodeficiency virus type 1 (HIV-1) vaccine must induce protective antibody responses, as well as CD4(+) and CD8(+) T cell responses, that can be effective despite extraordinary diversity of HIV-1. The consensus and mosaic immunogens are complete but artificial proteins, computationally designed to elicit immune responses with improved cross-reactive breadth, to attempt to overcome the challenge of global HIV diversity. In this study, we have compared the immunogenicity of a transmitted-founder (T/F) B clade Env (B.1059), a global group M consensus Env (Con-S), and a global trivalent mosaic Env protein in rhesus macaques. These antigens were delivered using a DNA prime-recombinant NYVAC (rNYVAC) vector and Env protein boost vaccination strategy. While Con-S Env was a single sequence, mosaic immunogens were a set of three Envs optimized to include the most common forms of potential T cell epitopes. Both Con-S and mosaic sequences retained common amino acids encompassed by both antibody and T cell epitopes and were central to globally circulating strains. Mosaics and Con-S Envs expressed as full-length proteins bound well to a number of neutralizing antibodies with discontinuous epitopes. Also, both consensus and mosaic immunogens induced significantly higher gamma interferon (IFN-γ) enzyme-linked immunosorbent spot assay (ELISpot) responses than B.1059 immunogen. Immunization with these proteins, particularly Con-S, also induced significantly higher neutralizing antibodies to viruses than B.1059 Env, primarily to tier 1 viruses. Both Con-S and mosaics stimulated more potent CD8-T cell responses against heterologous Envs than did B.1059. Both antibody and cellular data from this study strengthen the concept of using in silico-designed centralized immunogens for global HIV-1 vaccine development strategies. IMPORTANCE: There is an increasing appreciation for the importance of vaccine-induced anti-Env antibody responses for preventing HIV-1 acquisition. This nonhuman primate study demonstrates that in silico-designed global HIV-1 immunogens, designed for a human clinical trial, are capable of eliciting not only T lymphocyte responses but also potent anti-Env antibody responses.


Asunto(s)
VIH-1/inmunología , Vacunas contra el SIDAS/inmunología , Vacunación/métodos , Vacunas de ADN/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Antígenos Virales/genética , Antígenos Virales/inmunología , Aspartato Aminotransferasas , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Secuencia de Consenso , Ensayo de Immunospot Ligado a Enzimas , Anticuerpos Anti-VIH/sangre , VIH-1/genética , Humanos , Interferón gamma/metabolismo , Macaca mulatta , Vacunas contra el SIDAS/administración & dosificación , Vacunas contra el SIDAS/genética , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
3.
Retrovirology ; 7: 7, 2010 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-20122164

RESUMEN

Breast milk transmission remains a major mode of infant HIV acquisition, yet anatomic and immunologic forces shaping virus quasispecies in milk are not well characterized. In this study, phylogenic analysis of envelope sequences of milk SIV variants revealed groups of nearly identical viruses, indicating local virus production. However, comparison of the patterns and rates of CTL escape of blood and milk virus demonstrated only subtle differences between the compartments. These findings suggest that a substantial fraction of milk viruses are produced by locally-infected cells, but are shaped by cellular immune pressures similar to that in the blood.


Asunto(s)
Sangre/virología , Mama/virología , Leche Humana/virología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/crecimiento & desarrollo , Animales , Análisis por Conglomerados , Femenino , Macaca mulatta , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Análisis de Secuencia de ADN , Homología de Secuencia , Virus de la Inmunodeficiencia de los Simios/clasificación , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/aislamiento & purificación
4.
Nat Commun ; 8: 15711, 2017 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-28593989

RESUMEN

The RV144 Thai trial HIV-1 vaccine of recombinant poxvirus (ALVAC) and recombinant HIV-1 gp120 subtype B/subtype E (B/E) proteins demonstrated 31% vaccine efficacy. Here we design an ALVAC/Pentavalent B/E/E/E/E vaccine to increase the diversity of gp120 motifs in the immunogen to elicit a broader antibody response and enhance protection. We find that immunization of rhesus macaques with the pentavalent vaccine results in protection of 55% of pentavalent-vaccine-immunized macaques from simian-human immunodeficiency virus (SHIV) challenge. Systems serology of the antibody responses identifies plasma antibody binding to HIV-infected cells, peak ADCC antibody titres, NK cell-mediated ADCC and antibody-mediated activation of MIP-1ß in NK cells as the four immunological parameters that best predict decreased infection risk that are improved by the pentavalent vaccine. Thus inclusion of additional gp120 immunogens to a pox-prime/protein boost regimen can augment antibody responses and enhance protection from a SHIV challenge in rhesus macaques.


Asunto(s)
Vacunas contra el SIDA/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Células Asesinas Naturales/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Animales , Proteínas del Sistema Complemento/inmunología , Epítopos/inmunología , Femenino , Anticuerpos Anti-VIH/inmunología , VIH-1 , Humanos , Células Asesinas Naturales/citología , Leucocitos Mononucleares/citología , Macaca mulatta , Masculino , Mutación , Pruebas de Neutralización , Fagocitosis , Filogenia , Valor Predictivo de las Pruebas , Unión Proteica , Proteínas Recombinantes/inmunología , Análisis de Regresión
5.
Virology ; 475: 37-45, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25462344

RESUMEN

Simian-human immunodeficiency viruses (SHIVs) that mirror natural transmitted/founder (T/F) viruses in man are needed for evaluation of HIV-1 vaccine candidates in nonhuman primates. Currently available SHIVs contain HIV-1 env genes from chronically-infected individuals and do not reflect the characteristics of biologically relevant HIV-1 strains that mediate human transmission. We chose to develop clade C SHIVs, as clade C is the major infecting subtype of HIV-1 in the world. We constructed 10 clade C SHIVs expressing Env proteins from T/F viruses. Three of these ten clade C SHIVs (SHIV KB9 C3, SHIV KB9 C4 and SHIV KB9 C5) replicated in naïve rhesus monkeys. These three SHIVs are mucosally transmissible and are neutralized by sCD4 and several HIV-1 broadly neutralizing antibodies. However, like natural T/F viruses, they exhibit low Env reactivity and a Tier 2 neutralization sensitivity. Of note, none of the clade C T/F SHIVs elicited detectable autologous neutralizing antibodies in the infected monkeys, even though antibodies that neutralized a heterologous Tier 1 HIV-1 were generated. Challenge with these three new clade C SHIVs will provide biologically relevant tests for vaccine protection in rhesus macaques.


Asunto(s)
VIH-1/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/genética , Proteínas del Envoltorio Viral/metabolismo , Animales , Regulación Viral de la Expresión Génica/fisiología , Células HEK293 , Humanos , Mutación , Filogenia , Viremia
6.
Sci Transl Med ; 3(81): 81ra36, 2011 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-21543722

RESUMEN

The RV144 vaccine trial in Thailand demonstrated that an HIV vaccine could prevent infection in humans and highlights the importance of understanding protective immunity against HIV. We used a nonhuman primate model to define immune and genetic mechanisms of protection against mucosal infection by the simian immunodeficiency virus (SIV). A plasmid DNA prime/recombinant adenovirus serotype 5 (rAd5) boost vaccine regimen was evaluated for its ability to protect monkeys from infection by SIVmac251 or SIVsmE660 isolates after repeat intrarectal challenges. Although this prime-boost vaccine regimen failed to protect against SIVmac251 infection, 50% of vaccinated monkeys were protected from infection with SIVsmE660. Among SIVsmE660-infected animals, there was about a one-log reduction in peak plasma virus RNA in monkeys expressing the major histocompatibility complex class I allele Mamu-A*01, implicating cytotoxic T lymphocytes in the control of SIV replication once infection is established. Among Mamu-A*01-negative monkeys challenged with SIVsmE660, no CD8(+) T cell response or innate immune response was associated with protection against virus acquisition. However, low levels of neutralizing antibodies and an envelope-specific CD4(+) T cell response were associated with vaccine protection in these monkeys. Moreover, monkeys that expressed two TRIM5 alleles that restrict SIV replication were more likely to be protected from infection than monkeys that expressed at least one permissive TRIM5 allele. This study begins to elucidate the mechanisms of vaccine protection against immunodeficiency viruses and highlights the need to analyze these immune and genetic correlates of protection in future trials of HIV vaccine strategies.


Asunto(s)
Membrana Mucosa/virología , Virus de la Inmunodeficiencia de los Simios/patogenicidad , Alelos , Animales , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/metabolismo , Proteínas Portadoras/genética , Haplorrinos , Humanos
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