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1.
Nat Immunol ; 18(7): 762-770, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28504698

RESUMEN

Trafficking of tissue dendritic cells (DCs) via lymph is critical for the generation of cellular immune responses in draining lymph nodes (LNs). In the current study we found that DCs docked to the basolateral surface of lymphatic vessels and transited to the lumen through hyaluronan-mediated interactions with the lymph-specific endothelial receptor LYVE-1, in dynamic transmigratory-cup-like structures. Furthermore, we show that targeted deletion of the gene Lyve1, antibody blockade or depletion of the DC hyaluronan coat not only delayed lymphatic trafficking of dermal DCs but also blunted their capacity to prime CD8+ T cell responses in skin-draining LNs. Our findings uncovered a previously unknown function for LYVE-1 and show that transit through the lymphatic network is initiated by the recognition of leukocyte-derived hyaluronan.


Asunto(s)
Células Dendríticas/inmunología , Células Endoteliales/metabolismo , Glicoproteínas/genética , Ácido Hialurónico/metabolismo , Vasos Linfáticos/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animales , Movimiento Celular/inmunología , Células Dendríticas/metabolismo , Endotelio Linfático/citología , Endotelio Linfático/metabolismo , Citometría de Flujo , Glicoproteínas/metabolismo , Humanos , Inmunidad Celular/inmunología , Ganglios Linfáticos/inmunología , Proteínas de Transporte de Membrana , Ratones , Ratones Noqueados , Ratones Transgénicos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/inmunología
2.
Lancet ; 395(10227): 888-898, 2020 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-32085823

RESUMEN

BACKGROUND: Antiretroviral therapy (ART) cannot cure HIV infection because of a persistent reservoir of latently infected cells. Approaches that force HIV transcription from these cells, making them susceptible to killing-termed kick and kill regimens-have been explored as a strategy towards an HIV cure. RIVER is the first randomised trial to determine the effect of ART-only versus ART plus kick and kill on markers of the HIV reservoir. METHODS: This phase 2, open-label, multicentre, randomised, controlled trial was undertaken at six clinical sites in the UK. Patients aged 18-60 years who were confirmed as HIV-positive within a maximum of the past 6 months and started ART within 1 month from confirmed diagnosis were randomly assigned by a computer generated randomisation list to receive ART-only (control) or ART plus the histone deacetylase inhibitor vorinostat (the kick) and replication-deficient viral vector T-cell inducing vaccines encoding conserved HIV sequences ChAdV63. HIVconsv-prime and MVA.HIVconsv-boost (the kill; ART + V + V; intervention). The primary endpoint was total HIV DNA isolated from peripheral blood CD4+ T-cells at weeks 16 and 18 after randomisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT02336074. FINDINGS: Between June 14, 2015 and Jul 11, 2017, 60 men with HIV were randomly assigned to receive either an ART-only (n=30) or an ART + V + V (n=30) regimen; all 60 participants completed the study, with no loss-to-follow-up. Mean total HIV DNA at weeks 16 and 18 after randomisation was 3·02 log10 copies HIV DNA per 106 CD4+ T-cells in the ART-only group versus 3·06 log10 copies HIV DNA per 106 CD4+ T-cells in ART + V + V group, with no statistically significant difference between the two groups (mean difference of 0·04 log10 copies HIV DNA per 106 CD4+ T-cells [95% CI -0·03 to 0·11; p=0·26]). There were no intervention-related serious adverse events. INTERPRETATION: This kick and kill approach conferred no significant benefit compared with ART alone on measures of the HIV reservoir. Although this does not disprove the efficacy kick and kill strategy, for future trials enhancement of both kick and kill agents will be required. FUNDING: Medical Research Council (MR/L00528X/1).


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Antirretrovirales/uso terapéutico , Reservorios de Enfermedades , Infecciones por VIH , Inhibidores de Histona Desacetilasas/administración & dosificación , Vorinostat/administración & dosificación , Adulto , ADN Viral/análisis , Infecciones por VIH/tratamiento farmacológico , Humanos , Masculino , Transcripción Genética/efectos de los fármacos , Resultado del Tratamiento
3.
PLoS Pathog ; 15(2): e1007564, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30817809

RESUMEN

There are a number of vaccine candidates under development against a small number of the most common outbreak filoviruses all employing the virus glycoprotein (GP) as the vaccine immunogen. However, antibodies induced by such GP vaccines are typically autologous and limited to the other members of the same species. In contrast, T-cell vaccines offer a possibility to design a single pan-filovirus vaccine protecting against all known and even likely existing, but as yet unencountered members of the family. Here, we used a cross-filovirus immunogen based on conserved regions of the filovirus nucleoprotein, matrix and polymerase to construct simian adenovirus- and poxvirus MVA-vectored vaccines, and in a proof-of-concept study demonstrated a protection of the BALB/c and C57BL/6J mice against high, lethal challenges with Ebola and Marburg viruses, two distant members of the family, by vaccine-elicited T cells in the absence of GP antibodies.


Asunto(s)
Filoviridae/inmunología , Linfocitos T/inmunología , Vacunas Virales/farmacología , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Vacunas contra el Virus del Ébola , Ebolavirus/patogenicidad , Femenino , Filoviridae/metabolismo , Filoviridae/patogenicidad , Fiebre Hemorrágica Ebola , Inmunidad Celular/inmunología , Masculino , Marburgvirus/patogenicidad , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Prueba de Estudio Conceptual , Linfocitos T/metabolismo
4.
Matern Child Nutr ; 17(2): e13110, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33269548

RESUMEN

With expanded HIV treatment and prevention programmes, most infants born to HIV-positive women are uninfected, but the patterns and determinants of their growth are not well described. This study aimed to assess growth patterns in a cohort of HIV-exposed uninfected (HEU) infants who participated in an experimental HIV vaccine trial and to test for associations with maternal and infant factors, including in-utero exposure to antiretroviral therapy (ART), mode of delivery, exclusive breastfeeding, mother's education and receipt of the vaccine. Infants in the trial were seen at regular clinic visits from birth to 48 weeks of age. From the anthropometric measurements at these visits, weight-for-age z-scores (WAZ), weight-for-length z-scores (WLZ) and length-for-age z-scores (LAZ) were computed using World Health Organization (WHO) software and reference tables. Growth patterns were investigated with respect to maternal and infant factors, using linear mixed regression models. From 94 infants included at birth, growth data were available for 75.5% at 48 weeks. The determinants of infant growth in this population are multifactorial: infant LAZ during the first year was significantly lower among infants delivered by caesarean section (p = 0.043); both WAZ and LAZ were depressed among infants with longer exposure to maternal ART (WAZ: p = 0.015; LAZ: p < 0.0001) and among infants of mothers with lower educational level (WAZ: p = 0.038; LAZ: p < 0.0001); the effect of maternal education was modified by breastfeeding practice, with no differences seen in exclusively breastfed infants. These findings inform intervention strategies to preserve growth in this vulnerable infant population.


Asunto(s)
Infecciones por VIH , Complicaciones Infecciosas del Embarazo , Lactancia Materna , Cesárea , Estudios de Cohortes , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Lactante , Recién Nacido , Embarazo , Complicaciones Infecciosas del Embarazo/prevención & control
5.
J Virol ; 93(7)2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30674626

RESUMEN

Cytotoxic T lymphocytes (CTLs) with strong abilities to suppress HIV-1 replication and recognize circulating HIV-1 could be key for both HIV-1 cure and prophylaxis. We recently designed conserved mosaic T-cell vaccine immunogens (tHIVconsvX) composed of 6 Gag and Pol regions. Since the tHIVconsvX vaccine targets conserved regions common to most global HIV-1 variants and employs a bivalent mosaic design, it is expected that it could be universal if the vaccine works. Although we recently demonstrated that CTLs specific for 5 Gag epitopes in the vaccine immunogens had strong ability to suppress HIV-1 replication in vitro and in vivo, it remains unknown whether the Pol region-specific CTLs are equally efficient. In this study, we investigated CTLs specific for Pol epitopes in the immunogens in treatment-naive Japanese patients infected with HIV-1 clade B. Overall, we mapped 20 reported and 5 novel Pol conserved epitopes in tHIVconsvX. Responses to 6 Pol epitopes were significantly associated with good clinical outcome, suggesting that CTLs specific for these 6 Pol epitopes had a strong ability to suppress HIV-1 replication in HIV-1-infected individuals. In vitro T-cell analyses further confirmed that the Pol-specific CTLs could effectively suppress HIV-1 replication. The present study thus demonstrated that the Pol regions of the vaccine contained protective epitopes. T-cell responses to the previous 5 Gag and present 6 Pol protective epitopes together also showed a strong correlation with better clinical outcome. These findings support the testing of the conserved mosaic vaccine in HIV-1 cure and prevention in humans.IMPORTANCE It is likely necessary for an effective AIDS vaccine to elicit CD8+ T cells with the ability to recognize circulating HIV-1 and suppress its replication. We recently developed novel bivalent mosaic T-cell vaccine immunogens composed of conserved regions of the Gag and Pol proteins matched to at least 80% globally circulating HIV-1 isolates. Nevertheless, it remains to be proven if vaccination with these immunogens can elicit T cells with the ability to suppress HIV-1 replication. It is well known that Gag-specific T cells can suppress HIV-1 replication more effectively than T cells specific for epitopes in other proteins. We recently identified 5 protective Gag epitopes in the vaccine immunogens. In this study, we identified T cells specific for 6 Pol epitopes present in the immunogens with strong abilities to suppress HIV-1 in vivo and in vitro This study further encourages clinical testing of the conserved mosaic T-cell vaccine in HIV-1 prevention and cure.


Asunto(s)
Vacunas contra el SIDA/inmunología , Secuencia Conservada/inmunología , Epítopos de Linfocito T/inmunología , Productos del Gen pol/inmunología , VIH-1/inmunología , Linfocitos T Citotóxicos/inmunología , Replicación Viral/inmunología , Secuencia de Aminoácidos , Línea Celular , Reacciones Cruzadas/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Seropositividad para VIH/inmunología , Seropositividad para VIH/virología , Humanos , Linfocitos T Citotóxicos/virología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología
6.
Proc Natl Acad Sci U S A ; 113(20): 5682-7, 2016 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-27114505

RESUMEN

The αß T-cell coreceptor CD4 enhances immune responses more than 1 million-fold in some assays, and yet the affinity of CD4 for its ligand, peptide-major histocompatibility class II (pMHC II) on antigen-presenting cells, is so weak that it was previously unquantifiable. Here, we report that a soluble form of CD4 failed to bind detectably to pMHC II in surface plasmon resonance-based assays, establishing a new upper limit for the solution affinity at 2.5 mM. However, when presented multivalently on magnetic beads, soluble CD4 bound pMHC II-expressing B cells, confirming that it is active and allowing mapping of the native coreceptor binding site on pMHC II. Whereas binding was undetectable in solution, the affinity of the CD4/pMHC II interaction could be measured in 2D using CD4- and adhesion molecule-functionalized, supported lipid bilayers, yielding a 2D Kd of ∼5,000 molecules/µm(2) This value is two to three orders of magnitude higher than previously measured 2D Kd values for interacting leukocyte surface proteins. Calculations indicated, however, that CD4/pMHC II binding would increase rates of T-cell receptor (TCR) complex phosphorylation by threefold via the recruitment of Lck, with only a small, 2-20% increase in the effective affinity of the TCR for pMHC II. The affinity of CD4/pMHC II therefore seems to be set at a value that increases T-cell sensitivity by enhancing phosphorylation, without compromising ligand discrimination.


Asunto(s)
Antígenos CD4/química , Antígeno HLA-A24/química , Cadenas HLA-DRB1/química , Sitios de Unión , Antígenos CD4/metabolismo , Células HEK293 , Antígeno HLA-A24/metabolismo , Cadenas HLA-DRB1/metabolismo , Humanos , Proteínas de Unión a Maltosa/química , Modelos Moleculares , Fosforilación , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Mapeo de Interacción de Proteínas , Procesamiento Proteico-Postraduccional , Estabilidad Proteica , Resonancia por Plasmón de Superficie
7.
Retrovirology ; 15(1): 46, 2018 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-29970102

RESUMEN

BACKGROUND: Development of AIDS vaccines for effective prevention of circulating HIV-1 is required, but no trial has demonstrated definitive effects on the prevention. Several recent T-cell vaccine trials showed no protection against HIV-1 acquisition although the vaccines induced HIV-1-specific T-cell responses, suggesting that the vaccine-induced T cells have insufficient capacities to suppress HIV-1 replication and/or cross-recognize circulating HIV-1. Therefore, it is necessary to develop T-cell vaccines that elicit T cells recognizing shared protective epitopes with strong ability to suppress HIV-1. We recently designed T-cell mosaic vaccine immunogens tHIVconsvX composed of 6 conserved Gag and Pol regions and demonstrated that the T-cell responses to peptides derived from the vaccine immunogens were significantly associated with lower plasma viral load (pVL) and higher CD4+ T-cell count (CD4 count) in HIV-1-infected, treatment-naive Japanese individuals. However, it remains unknown T cells of which specificities have the ability to suppress HIV-1 replication. In the present study, we sought to identify more T cells specific for protective Gag epitopes in the vaccine immunogens, and analyze their abilities to suppress HIV-1 replication and recognize epitope variants in circulating HIV-1. RESULTS: We determined 17 optimal Gag epitopes and their HLA restriction, and found that T-cell responses to 9 were associated significantly with lower pVL and/or higher CD4 count. T-cells recognizing 5 of these Gag peptides remained associated with good clinical outcome in 221 HIV-1-infected individuals even when comparing responders and non-responders with the same restricting HLA alleles. Although it was known previously that T cells specific for 3 of these protective epitopes had strong abilities to suppress HIV-1 replication in vivo, here we demonstrated equivalent abilities for the 2 novel epitopes. Furthermore, T cells against all 5 Gag epitopes cross-recognized variants in majority of circulating HIV-1. CONCLUSIONS: We demonstrated that T cells specific for 5 Gag conserved epitopes in the tHIVconsvX have ability to suppress replication of circulating HIV-1 in HIV-1-infected individuals. Therefore, the tHIVconsvX vaccines have the right specificity to contribute to prevention of HIV-1 infection and eradication of latently infected cells following HIV-1 reactivation.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/fisiología , Replicación Viral/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Alelos , Secuencia de Aminoácidos , Línea Celular , Secuencia Conservada , Reacciones Cruzadas/inmunología , Mapeo Epitopo , Epítopos de Linfocito T/química , Infecciones por VIH/genética , Antígenos HLA/genética , Antígenos HLA/inmunología , Interacciones Huésped-Patógeno/inmunología , Humanos , Péptidos/química , Péptidos/inmunología , Especificidad del Receptor de Antígeno de Linfocitos T , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/química
8.
Mol Ther ; 25(2): 494-503, 2017 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-28153096

RESUMEN

To be effective against HIV type 1 (HIV-1), vaccine-induced T cells must selectively target epitopes, which are functionally conserved (present in the majority of currently circulating and reactivated HIV-1 strains) and, at the same time, beneficial (responses to which are associated with better clinical status and control of HIV-1 replication), and rapidly reach protective frequencies upon exposure to the virus. Heterologous prime-boost regimens using virally vectored vaccines are currently the most promising vaccine strategies; nevertheless, induction of robust long-term memory remains challenging. To this end, lentiviral vectors induce high frequencies of memory cells due to their low-inflammatory nature, while typically inducing only low anti-vector immune responses. Here, we describe construction of novel candidate vaccines ZVex.tHIVconsv1 and ZVex.tHIVconsv2, which are based on an integration-deficient lentiviral vector platform with preferential transduction of human dendritic cells and express a bivalent mosaic of conserved-region T cell immunogens with a high global HIV-1 match. Each of the two mosaic vaccines was individually immunogenic. When administered together in heterologous prime-boost regimens with chimpanzee adenovirus and/or poxvirus modified vaccinia virus Ankara (MVA) vaccines to BALB/c and outbred CD1-Swiss mice, they induced a median frequency of over 6,000 T cells/106 splenocytes, which were plurifunctional, broadly specific, and cross-reactive. These results support further development of this vaccine concept.


Asunto(s)
Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Vectores Genéticos/genética , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Lentivirus/genética , Linfocitos T/inmunología , Linfocitos T/metabolismo , Vacunas contra el SIDA/genética , Vacunas contra el SIDA/inmunología , Animales , Secuencia Conservada , Modelos Animales de Enfermedad , Epítopos/genética , Epítopos/inmunología , Femenino , Orden Génico , Infecciones por VIH/virología , Humanos , Inmunidad Celular , Ratones , Péptidos/genética , Péptidos/inmunología
9.
Eur J Immunol ; 46(1): 60-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26467324

RESUMEN

Recognition and eradication of infected cells by cytotoxic T lymphocytes is a key defense mechanism against intracellular pathogens. High-throughput definition of HLA class I-associated immunopeptidomes by mass spectrometry is an increasingly important analytical tool to advance our understanding of the induction of T-cell responses against pathogens such as HIV-1. We utilized a liquid chromatography tandem mass spectrometry workflow including de novo-assisted database searching to define the HLA class I-associated immunopeptidome of HIV-1-infected human cells. We here report for the first time the identification of 75 HIV-1-derived peptides bound to HLA class I complexes that were purified directly from HIV-1-infected human primary CD4(+) T cells and the C8166 human T-cell line. Importantly, one-third of eluted HIV-1 peptides had not been previously known to be presented by HLA class I. Over 82% of the identified sequences originated from viral protein regions for which T-cell responses have previously been reported but for which the precise HLA class I-binding sequences have not yet been defined. These results validate and expand the current knowledge of virus-specific antigenic peptide presentation during HIV-1 infection and provide novel targets for T-cell vaccine development.


Asunto(s)
Antígenos Virales/inmunología , VIH-1/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Línea Celular , Cromatografía Líquida de Alta Presión , Humanos , Linfocitos T Citotóxicos/inmunología , Espectrometría de Masas en Tándem
10.
PLoS Pathog ; 11(2): e1004658, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25723536

RESUMEN

Defining the components of an HIV immunogen that could induce effective CD8+ T cell responses is critical to vaccine development. We addressed this question by investigating the viral targets of CD8+ T cells that potently inhibit HIV replication in vitro, as this is highly predictive of virus control in vivo. We observed broad and potent ex vivo CD8+ T cell-mediated viral inhibitory activity against a panel of HIV isolates among viremic controllers (VC, viral loads <5000 copies/ml), in contrast to unselected HIV-infected HIV Vaccine trials Network (HVTN) participants. Viral inhibition of clade-matched HIV isolates was strongly correlated with the frequency of CD8+ T cells targeting vulnerable regions within Gag, Pol, Nef and Vif that had been identified in an independent study of nearly 1000 chronically infected individuals. These vulnerable and so-called "beneficial" regions were of low entropy overall, yet several were not predicted by stringent conservation algorithms. Consistent with this, stronger inhibition of clade-matched than mismatched viruses was observed in the majority of subjects, indicating better targeting of clade-specific than conserved epitopes. The magnitude of CD8+ T cell responses to beneficial regions, together with viral entropy and HLA class I genotype, explained up to 59% of the variation in viral inhibitory activity, with magnitude of the T cell response making the strongest unique contribution. However, beneficial regions were infrequently targeted by CD8+ T cells elicited by vaccines encoding full-length HIV proteins, when the latter were administered to healthy volunteers and HIV-positive ART-treated subjects, suggesting that immunodominance hierarchies undermine effective anti-HIV CD8+ T cell responses. Taken together, our data support HIV immunogen design that is based on systematic selection of empirically defined vulnerable regions within the viral proteome, with exclusion of immunodominant decoy epitopes that are irrelevant for HIV control.


Asunto(s)
Vacunas contra el SIDA/uso terapéutico , Linfocitos T CD8-positivos/patología , Infecciones por VIH/prevención & control , Infecciones por VIH/terapia , VIH-1/inmunología , Inmunidad Celular , Vacunas contra el SIDA/inmunología , Adulto , Linfocitos T CD8-positivos/clasificación , Epítopos de Linfocito T/inmunología , Femenino , Infecciones por VIH/inmunología , Humanos , Epítopos Inmunodominantes/inmunología , Masculino , Persona de Mediana Edad , Vacunación , Carga Viral/inmunología , Adulto Joven
11.
Mol Ther ; 24(2): 375-384, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26581160

RESUMEN

The biggest roadblock in development of effective vaccines against human immunodeficiency virus type 1 (HIV-1) is the virus genetic diversity. For T-cell vaccine, this can be tackled by focusing the vaccine-elicited T-cells on the highly functionally conserved regions of HIV-1 proteins, mutations in which typically cause a replicative fitness loss, and by computing multivalent mosaic proteins, which maximize the coverage of potential 9-mer T-cell epitopes of the input viral sequences. Our first conserved region vaccines HIVconsv employed clade alternating consensus sequences and showed promise in the initial clinical trials in terms of magnitude and breadth of elicited CD8(+) T-cells. Here, monitoring T-cells restricted by HLA-A*02:01 in transgenic mice, we assessed whether or not the tHIVconsv design (HIVconsv with a tissue plasminogen activator leader sequence) benefits from combining with a complementing conserved mosaic immunogen tHIVcmo, and compared the bivalent immunization to that with trivalent conserved mosaic vaccines. A hierarchy of tHIVconsv ≤ tHIVconsv+tHIVcmo < tCmo1+tCmo2+tCmo3 vaccinations for induction of CD8(+) T-cell responses was observed in terms of recognition of tested peptide variants. Thus, our HLA-A*02:01-restricted epitope data concur with previously published mouse and macaque observations and suggest that even conserved region vaccines benefit from oligovalent mosaic design.


Asunto(s)
Vacunas contra el SIDA/inmunología , Epítopos de Linfocito T/metabolismo , Infecciones por VIH/terapia , Antígeno HLA-A2/metabolismo , Animales , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Ratones , Ratones Transgénicos
12.
Mol Ther ; 24(4): 832-42, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26743582

RESUMEN

An effective human immunodeficiency virus type 1 (HIV-1) vaccine is the best solution for halting the acquired immune deficiency syndrome epidemic. Here, we describe the design and preclinical immunogenicity of T-cell vaccine expressing novel immunogens tHIVconsvX, vectored by DNA, simian (chimpanzee) adenovirus, and poxvirus modified vaccinia virus Ankara (MVA), a combination highly immunogenic in humans. The tHIVconsvX immunogens combine the three leading strategies for elicitation of effective CD8(+) T cells: use of regions of HIV-1 proteins functionally conserved across all M group viruses (to make HIV-1 escape costly on viral fitness), inclusion of bivalent complementary mosaic immunogens (to maximize global epitope matching and breadth of responses, and block common escape paths), and inclusion of epitopes known to be associated with low viral load in infected untreated people (to induce field-proven protective responses). tHIVconsvX was highly immunogenic in two strains of mice. Furthermore, the magnitude and breadth of CD8(+) T-cell responses to tHIVconsvX-derived peptides in treatment-naive HIV-1(+) patients significantly correlated with high CD4(+) T-cell count and low viral load. Overall, the tHIVconsvX design, combining the mosaic and conserved-region approaches, provides an indisputably better coverage of global HIV-1 variants than previous T-cell vaccines. These immunogens delivered in a highly immunogenic framework of adenovirus prime and MVA boost are ready for clinical development.


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/terapia , Adenovirus de los Simios/inmunología , Animales , Recuento de Linfocito CD4 , VIH-1/fisiología , Células HeLa , Humanos , Ratones , Virus Vaccinia/inmunología , Carga Viral
13.
J Virol ; 89(11): 5760-71, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25810538

RESUMEN

UNLABELLED: Cytotoxic T cells substantially contribute to the control of intracellular pathogens such as human immunodeficiency virus type 1 (HIV-1). Here, we evaluated the immunopeptidome of Jurkat cells infected with the vaccine candidate MVA.HIVconsv, which delivers HIV-1 conserved antigenic regions by using modified vaccinia virus Ankara (MVA). We employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify 6,358 unique peptides associated with the class I human leukocyte antigen (HLA), of which 98 peptides were derived from the MVA vector and 7 were derived from the HIVconsv immunogen. Human vaccine recipients responded to the peptide sequences identified by LC-MS/MS. Peptides derived from the conserved HIV-1 regions were readily detected as early as 1.5 h after MVA.HIVconsv infection. Four of the seven conserved peptides were monitored between 0 and 3.5 h of infection by using quantitative mass spectrometry (Q-MS), and their abundance in HLA class I associations reflected levels of the whole HIVconsv protein in the cell. While immunopeptides delivered by the incoming MVA vector proteins could be detected, all early HIVconsv-derived immunopeptides were likely synthesized de novo. MVA.HIVconsv infection generally altered the composition of HLA class I-associated human (self) peptides, but these changes corresponded only partially to changes in the whole cell host protein abundance. IMPORTANCE: The vast changes in cellular antigen presentation after infection of cells with a vectored vaccine, as shown here for MVA.HIVconsv, highlight the complexity of factors that need to be considered for efficient antigen delivery and presentation. Identification and quantitation of HLA class I-associated peptides by Q-MS will not only find broad application in T-cell epitope discovery but also inform vaccine design and allow evaluation of efficient epitope presentation using different delivery strategies.


Asunto(s)
Vacunas contra el SIDA/inmunología , Antígenos Virales/análisis , VIH-1/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Péptidos/análisis , Linfocitos T Citotóxicos/química , Cromatografía Liquida , Vectores Genéticos , Humanos , Células Jurkat , Linfocitos T Citotóxicos/inmunología , Espectrometría de Masas en Tándem , Factores de Tiempo , Vacunas Sintéticas/inmunología , Virus Vaccinia/genética , Virus Vaccinia/inmunología
14.
J Transl Med ; 13: 60, 2015 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-25879820

RESUMEN

BACKGROUND: None of the HIV T-cell vaccine candidates that have reached advanced clinical testing have been able to induce protective T cell immunity. A major reason for these failures may have been suboptimal T cell immunogen designs. METHODS: To overcome this problem, we used a novel immunogen design approach that is based on functional T cell response data from more than 1,000 HIV-1 clade B and C infected individuals and which aims to direct the T cell response to the most vulnerable sites of HIV-1. RESULTS: Our approach identified 16 regions in Gag, Pol, Vif and Nef that were relatively conserved and predominantly targeted by individuals with reduced viral loads. These regions formed the basis of the HIVACAT T-cell Immunogen (HTI) sequence which is 529 amino acids in length, includes more than 50 optimally defined CD4(+) and CD8(+) T-cell epitopes restricted by a wide range of HLA class I and II molecules and covers viral sites where mutations led to a dramatic reduction in viral replicative fitness. In both, C57BL/6 mice and Indian rhesus macaques immunized with an HTI-expressing DNA plasmid (DNA.HTI) induced broad and balanced T-cell responses to several segments within Gag, Pol, and Vif. DNA.HTI induced robust CD4(+) and CD8(+) T cell responses that were increased by a booster vaccination using modified virus Ankara (MVA.HTI), expanding the DNA.HTI induced response to up to 3.2% IFN-γ T-cells in macaques. HTI-specific T cells showed a central and effector memory phenotype with a significant fraction of the IFN-γ(+) CD8(+) T cells being Granzyme B(+) and able to degranulate (CD107a(+)). CONCLUSIONS: These data demonstrate the immunogenicity of a novel HIV-1 T cell vaccine concept that induced broadly balanced responses to vulnerable sites of HIV-1 while avoiding the induction of responses to potential decoy targets that may divert effective T-cell responses towards variable and less protective viral determinants.


Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/inmunología , Linfocitos T/inmunología , Alelos , Secuencia de Aminoácidos , Animales , Antivirales/inmunología , Linfocitos T CD4-Positivos/inmunología , Estudios de Cohortes , Epítopos/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Células HEK293 , Haplotipos , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Inmunidad Celular , Inmunidad Humoral , Memoria Inmunológica , Macaca mulatta , Masculino , Ratones Endogámicos C57BL , Péptidos/química , Péptidos/inmunología , Linfocitos T Citotóxicos/inmunología , Vacunación
15.
Mol Ther ; 22(2): 464-475, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24166483

RESUMEN

Virus diversity and escape from immune responses are the biggest challenges to the development of an effective vaccine against HIV-1. We hypothesized that T-cell vaccines targeting the most conserved regions of the HIV-1 proteome, which are common to most variants and bear fitness costs when mutated, will generate effectors that efficiently recognize and kill virus-infected cells early enough after transmission to potentially impact on HIV-1 replication and will do so more efficiently than whole protein-based T-cell vaccines. Here, we describe the first-ever administration of conserved immunogen vaccines vectored using prime-boost regimens of DNA, simian adenovirus and modified vaccinia virus Ankara to uninfected UK volunteers. The vaccine induced high levels of effector T cells that recognized virus-infected autologous CD4(+) cells and inhibited HIV-1 replication by up to 5.79 log10. The virus inhibition was mediated by both Gag- and Pol- specific effector CD8(+) T cells targeting epitopes that are typically subdominant in natural infection. These results provide proof of concept for using a vaccine to target T cells at conserved epitopes, showing that these T cells can control HIV-1 replication in vitro.


Asunto(s)
Vacunas contra el SIDA/inmunología , Epítopos de Linfocito T/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Linfocitos T/inmunología , Vacunas contra el SIDA/genética , Adolescente , Adulto , Secuencia de Aminoácidos , Células Cultivadas , Secuencia Conservada/inmunología , Mapeo Epitopo , Epítopos de Linfocito T/química , Femenino , Infecciones por VIH/prevención & control , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Especificidad del Receptor de Antígeno de Linfocitos T/inmunología , Subgrupos de Linfocitos T/inmunología , Vacunas de ADN/genética , Vacunas de ADN/inmunología , Replicación Viral/inmunología , Adulto Joven , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen pol del Virus de la Inmunodeficiencia Humana/inmunología
16.
Nat Rev Immunol ; 2(4): 283-91, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12001999

RESUMEN

The rationale for developing anti-HIV vaccines that stimulate cytotoxic T-lymphocyte responses is given. We argue that such vaccines will work, provided that attention is paid to the development of memory T-cell responses that are strong and preferably activated. Furthermore, the vaccine should match the prevailing virus clade as closely as possible. Vaccines will have to stimulate a wide range of responses, but it is not clear how this can be achieved.


Asunto(s)
Vacunas contra el SIDA/inmunología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Linfocitos T CD8-positivos/inmunología , Citotoxicidad Inmunológica , VIH , Síndrome de Inmunodeficiencia Adquirida/virología , Animales , VIH/genética , VIH/inmunología , Humanos
17.
NPJ Vaccines ; 9(1): 74, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582771

RESUMEN

Recombinant native-like HIV-1 envelope glycoprotein (Env) trimers are used in candidate vaccines aimed at inducing broadly neutralizing antibodies. While state-of-the-art SOSIP or single-chain Env designs can be expressed as native-like trimers, undesired monomers, dimers and malformed trimers that elicit non-neutralizing antibodies are also formed, implying that these designs could benefit from further modifications for gene-based vaccination approaches. Here, we describe the triple tandem trimer (TTT) design, in which three Env protomers are genetically linked in a single open reading frame and express as native-like trimers. Viral vectored Env TTT induced similar neutralization titers but with a higher proportion of trimer-specific responses. The TTT design was also applied to generate influenza hemagglutinin (HA) trimers without the need for trimerization domains. Additionally, we used TTT to generate well-folded chimeric Env and HA trimers that harbor protomers from three different strains. In summary, the TTT design is a useful platform for the design of HIV-1 Env and influenza HA immunogens for a multitude of vaccination strategies.

18.
Eur J Immunol ; 42(12): 3243-55, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22930183

RESUMEN

The popularity of nonreplicating adenoviruses of chimpanzee origin (ChAdVs) as vectors for subunit vaccines is on the rise. This is mainly for their excellent safety and impressive immunogenicity observed in human studies to date. Here, we recloned the chimpanzee adenovirus sero type 68 (ChAdV-68), also designated SAdV-25 and AdC68, genome and demonstrated its straightforward genetic manipulation facilitated by the use of bacterial artificial chromosome recombineering. To generate the ChAdV68.GagB vaccine, the HIV-1 consensus clade B Gag-derived Tg was inserted into the E1 region. In part confirming previous observations, the ChAdV68.GagB vaccine alone and in heterologous prime-boost regimens with plasmid DNA- and modified vaccinia virus Ankara (MVA)-vectored vaccines induced robust polyfunctional HIV-1-specific CD8(+) and CD4(+) T-cell responses with a gut-homing phenotype. Importantly, we showed that when a single epitope is expressed as an immunodominant CD8(+) T-cell determinant, responses elicited by ChAdV68.GagB alone and in combination lowered surrogate challenge EcoHIV/NDK (where EcoHIV is chimeric ecotropic HIV) virus load in mice both at the peak T-cell frequencies 2 weeks after vaccination and 16 weeks later indicating development of protective effector memory. These results parallel the immunogenicity of similar vaccine regimens in macaques and an ongoing phase I/IIa trial in humans, and support further development of vaccines vectored by ChAdVs.


Asunto(s)
Vacunas contra el SIDA/inmunología , Adenoviridae , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/prevención & control , VIH-1/inmunología , Inmunización Secundaria , Virus Vaccinia , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/genética , Vacunas contra el SIDA/farmacología , Animales , Ensayos Clínicos Fase I como Asunto , Ensayos Clínicos Fase II como Asunto , Genoma Viral/genética , Genoma Viral/inmunología , Células HEK293 , Infecciones por VIH/genética , Infecciones por VIH/inmunología , VIH-1/genética , Humanos , Macaca , Ratones , Ratones Endogámicos BALB C , Pan troglodytes , Factores de Tiempo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genética
19.
J Virol ; 86(8): 4082-90, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22318135

RESUMEN

Vaccination using "naked" DNA is a highly attractive strategy for induction of pathogen-specific immune responses; however, it has been only weakly immunogenic in humans. Previously, we constructed DNA-launched Semliki Forest virus replicons (DREP), which stimulate pattern recognition receptors and induce augmented immune responses. Also, in vivo electroporation was shown to enhance immune responses induced by conventional DNA vaccines. Here, we combine these two approaches and show that in vivo electroporation increases CD8(+) T cell responses induced by DREP and consequently decreases the DNA dose required to induce a response. The vaccines used in this study encode the multiclade HIV-1 T cell immunogen HIVconsv, which is currently being evaluated in clinical trials. Using intradermal delivery followed by electroporation, the DREP.HIVconsv DNA dose could be reduced to as low as 3.2 ng to elicit frequencies of HIV-1-specific CD8(+) T cells comparable to those induced by 1 µg of a conventional pTH.HIVconsv DNA vaccine, representing a 625-fold molar reduction in dose. Responses induced by both DREP.HIVconsv and pTH.HIVconsv were further increased by heterologous vaccine boosts employing modified vaccinia virus Ankara MVA.HIVconsv and attenuated chimpanzee adenovirus ChAdV63.HIVconsv. Using the same HIVconsv vaccines, the mouse observations were supported by an at least 20-fold-lower dose of DNA vaccine in rhesus macaques. These data point toward a strategy for overcoming the low immunogenicity of DNA vaccines in humans and strongly support further development of the DREP vaccine platform for clinical evaluation.


Asunto(s)
ADN Viral/inmunología , VIH-1/inmunología , Plásmidos/inmunología , Virus de los Bosques Semliki/genética , Virus de los Bosques Semliki/inmunología , Linfocitos T/inmunología , Vacunas de ADN/inmunología , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/genética , Vacunas contra el SIDA/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Línea Celular , ADN Viral/genética , Electroporación , Femenino , Orden Génico , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Humanos , Macaca mulatta , Ratones , Ratones Endogámicos BALB C , Plásmidos/administración & dosificación , Plásmidos/genética , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética
20.
PLoS Pathog ; 7(5): e1002041, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21625575

RESUMEN

Immunodominance in T cell responses to complex antigens like viruses is still incompletely understood. Some data indicate that the dominant responses to viruses are not necessarily the most protective, while other data imply that dominant responses are the most important. The issue is of considerable importance to the rational design of vaccines, particularly against variable escaping viruses like human immunodeficiency virus type 1 and hepatitis C virus. Here, we showed that sequential inactivation of dominant epitopes up-ranks the remaining subdominant determinants. Importantly, we demonstrated that subdominant epitopes can induce robust responses and protect against whole viruses if they are allowed at least once in the vaccination regimen to locally or temporally dominate T cell induction. Therefore, refocusing T cell immune responses away from highly variable determinants recognized during natural virus infection towards subdominant, but conserved regions is possible and merits evaluation in humans.


Asunto(s)
Vacunas contra el SIDA/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/virología , Epítopos de Linfocito T/inmunología , VIH-1/inmunología , Epítopos Inmunodominantes/inmunología , Animales , Citocinas/análisis , Femenino , Ratones , Ratones Endogámicos BALB C , Reacción en Cadena de la Polimerasa
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