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Limited cellular levels of the HIV transcriptional activator Tat are one contributor to proviral latency that might be targeted in HIV cure strategies. We recently demonstrated that lipid nanoparticles containing HIV tat mRNA induce HIV expression in primary CD4 T cells. Here, we sought to further characterize tat mRNA in the context of several benchmark latency reversal agents (LRAs), including inhibitor of apoptosis protein antagonists (IAPi), bromodomain and extra-Terminal motif inhibitors (BETi), and histone deacetylase inhibitors (HDACi). tat mRNA reversed latency across several different cell line models of HIV latency, an effect dependent on the TAR hairpin loop. Synergistic enhancement of tat mRNA activity was observed with IAPi, HDACi, and BETi, albeit to variable degrees. In primary CD4 T cells from durably suppressed people with HIV, tat mRNA profoundly increased the frequencies of elongated, multiply-spliced, and polyadenylated HIV transcripts, while having a lesser impact on TAR transcript frequencies. tat mRNAs alone resulted in variable HIV p24 protein induction across donors. However, tat mRNA in combination with IAPi, BETi, or HDACi markedly enhanced HIV RNA and protein expression without overt cytotoxicity or cellular activation. Notably, combination regimens approached or in some cases exceeded the latency reversal activity of maximal mitogenic T cell stimulation. Higher levels of tat mRNA-driven HIV p24 induction were observed in donors with larger mitogen-inducible HIV reservoirs, and expression increased with prolonged exposure time. Combination LRA strategies employing both small molecule inhibitors and Tat delivered to CD4 T cells are a promising approach to effectively target the HIV reservoir.
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Infecciones por VIH , VIH-1 , Inhibidores de Histona Desacetilasas , Nanopartículas , Latencia del Virus , Productos del Gen tat del Virus de la Inmunodeficiencia Humana , Humanos , Fármacos Anti-VIH/farmacología , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/virología , Linfocitos T CD4-Positivos/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Antígenos VIH/genética , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , VIH-1/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Latencia del Virus/efectos de los fármacosRESUMEN
A major barrier to HIV-1 cure is caused by the pool of latently infected CD4 T-cells that persist under combination antiretroviral therapy (cART). This latent reservoir is capable of producing replication-competent infectious viruses once prolonged suppressive cART is withdrawn. Inducing the reactivation of HIV-1 gene expression in T-cells harboring a latent provirus in people living with HIV-1 under cART may result in depletion of this latent reservoir due to cytopathic effects or immune clearance. Studies have investigated molecules that reactivate HIV-1 gene expression, but to date, no latency reversal agent has been identified to eliminate latently infected cells harboring replication-competent HIV in cART-treated individuals. Stochastic fluctuations in HIV-1 tat gene expression have been described and hypothesized to allow the progression into proviral latency. We hypothesized that exposing latently infected CD4+ T-cells to Tat would result in effective latency reversal. Our results indicate the capacity of a truncated Tat protein and mRNA to reactivate HIV-1 in latently infected T-cells ex vivo to a similar degree as the protein kinase C agonist: phorbol 12-myristate 13-acetate, without T-cell activation or any significant transcriptome perturbation.
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Infecciones por VIH , VIH-1 , Activación Viral , Productos del Gen tat del Virus de la Inmunodeficiencia Humana , Humanos , Linfocitos T CD4-Positivos , Infecciones por VIH/genética , Infecciones por VIH/metabolismo , Provirus/genética , Latencia del Virus , Replicación Viral , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo , VIH-1/genética , VIH-1/metabolismoRESUMEN
Antigen-presenting cells are a heterogeneous group of cells that are characterized by their functional specialization. Consequently, targeting specific antigen-presenting cell subsets offers opportunities to induce distinct T cell responses. Here we report on the generation and use of nanobodies (Nbs) to target lentivectors specifically to human lymph node-resident myeloid dendritic cells, demonstrating that Nbs represent a powerful tool to redirect lentivectors to human antigen-presenting cell subsets.
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Células Presentadoras de Antígenos/inmunología , Vectores Genéticos/metabolismo , Lentivirus/genética , Lentivirus/metabolismo , Anticuerpos de Dominio Único/metabolismo , Animales , Humanos , Ganglios Linfáticos/inmunologíaRESUMEN
The use of DNA and viral vector-based vaccines for the induction of cellular immune responses is increasingly gaining interest. However, concerns have been raised regarding the safety of these immunization strategies. Due to the lack of their genome integration, mRNA-based vaccines have emerged as a promising alternative. In this study, we evaluated the potency of antigen-encoding mRNA complexed with the cationic lipid 1,2-dioleoyl-3trimethylammonium-propane/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOTAP/DOPE ) as a novel vaccination approach. We demonstrate that subcutaneous immunization of mice with mRNA encoding the HIV-1 antigen Gag complexed with DOTAP/DOPE elicits antigen-specific, functional T cell responses resulting in specific killing of Gag peptide-pulsed cells and the induction of humoral responses. In addition, we show that DOTAP/DOPE complexed antigen-encoding mRNA displays immune-activating properties characterized by secretion of type I interferon (IFN) and the recruitment of proinflammatory monocytes to the draining lymph nodes. Finally, we demonstrate that type I IFN inhibit the expression of DOTAP/DOPE complexed antigen-encoding mRNA and the subsequent induction of antigen-specific immune responses. These results are of high relevance as they will stimulate the design and development of improved mRNA-based vaccination approaches.
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Antígenos/inmunología , Inmunidad Celular/efectos de los fármacos , Interferón Tipo I/farmacología , ARN Mensajero/inmunología , Animales , Ratones , ARN Mensajero/administración & dosificaciónRESUMEN
Chronic infection with hepatitis B virus (HBV) develops in millions of patients per year, despite the availability of effective prophylactic vaccines. Patients who resolve acute HBV infection develop HBV-specific polyfunctional T cells accompanied by neutralizing antibodies, while in patients with chronic hepatitis B (CHB), immune cells are dysfunctional and impaired. We describe a lipid nanoparticle (LNP)-formulated mRNA vaccine, optimized for the expression of HBV core, polymerase, and surface (preS2-S) antigens with the aim of inducing an effective immune response in patients with CHB. Prime and prime/boost vaccination with LNP-formulated mRNA encoding for core, pol, and/or preS2-S dosing strategies were compared in naive C57BL/6 and BALB/c mice. Immune responses were assessed by IFN-γ ELISpot, intracellular cytokine staining (ICS), and ELISA for antibody production, whereas anti-viral efficacy was evaluated in the AAV-HBV mouse model. The mRNA vaccine induced strong antigen-specific polyfunctional T cell responses in these mouse models, accompanied by the emergence of anti-HBs and anti-HBe antibodies. After three immunizations, the antigen-specific immune stimulation resulted in up to 1.7 log10 IU/mL reduction in systemic HBV surface antigen (HBsAg), accompanied by a transient drop in systemic HBeAg, and this was observed in 50% of the AAV-HBV-transduced mice in the absence of additional modalities such as adjuvants, HBsAg reducing agents, or checkpoint inhibitors. However, no treatment-related effect on viremia was observed in the liver. These results warrant further optimization and evaluation of this mRNA vaccine as a candidate in a multimodal therapeutic regimen for the treatment of chronic HBV infection.
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BACKGROUND AND AIMS: Treatment with siRNAs that target HBV has demonstrated robust declines in HBV antigens. This effect is also observed in the AAV-HBV mouse model, which was used to investigate if two cycles of GalNAc-HBV-siRNA treatment could induce deeper declines in HBsAg levels or prevent rebound, and to provide insights into the liver immune microenvironment. METHODS: C57Bl/6 mice were transduced with one of two different titers of AAV-HBV for 28 days, resulting in stable levels of HBsAg of about 103 or 105 IU/mL. Mice were treated for 12 weeks (four doses q3wk) per cycle with 3 mg/kg of siRNA-targeting HBV or an irrelevant sequence either once (single treatment) or twice (retreatment) with an 8-week treatment pause in between. Blood was collected to evaluate viral parameters. Nine weeks after the last treatment, liver samples were collected to perform phenotyping, bulk RNA-sequencing, and immunohistochemistry. RESULTS: Independent of HBsAg baseline levels, treatment with HBV-siRNA induced a rapid decline in HBsAg levels, which then plateaued before gradually rebounding 12 weeks after treatment stopped. A second cycle of HBV-siRNA treatment induced a further decline in HBsAg levels in serum and the liver, reaching undetectable levels and preventing rebound when baseline levels were 103 IU/mL. This was accompanied with a significant increase in inflammatory macrophages in the liver and significant upregulation of regulatory T-cells and T-cells expressing immune checkpoint receptors. CONCLUSIONS: Retreatment induced an additional decline in HBsAg levels, reaching undetectable levels when baseline HBsAg levels were 3log10 or less. This correlated with T-cell activation and upregulation of Trem2.
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Antígenos de Superficie de la Hepatitis B , Virus de la Hepatitis B , Animales , Ratones , Virus de la Hepatitis B/genética , ARN Interferente Pequeño/genética , Hígado , Retratamiento , ADN Viral , Antivirales/uso terapéutico , Glicoproteínas de Membrana , Receptores InmunológicosRESUMEN
Research on liver-related conditions requires a robust and efficient method to purify viable hepatocytes, lymphocytes and all other liver resident cells, such as Kupffer or liver sinusoidal endothelial cells. Here we describe a novel purification method using liver enzymatic digestion, followed by a downstream optimized purification. Using this enzymatic digestion protocol, the resident liver cells as well as viable hepatocytes could be captured, compared to the classical mechanical liver disruption method. Moreover, single-cell RNA-sequencing demonstrated higher quality lymphocyte data in downstream analyses after the liver enzymatic digestion, allowing for studying of immunological responses or changes. In order to also understand the peripheral immune landscape, a protocol for lymphocyte purification from mouse systemic whole blood was optimized, allowing for efficient removal of red blood cells. The combination of microbeads and mRNA blockers allowed for a clean blood sample, enabling robust single-cell RNA-sequencing data. These two protocols for blood and liver provide important new methodologies for liver-related studies such as NASH, hepatitis virus infections or cancer research but also for immunology where high-quality cells are indispensable for further downstream assays.
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Leucocitos , Hígado , Animales , Ratones , Hígado/inmunología , Leucocitos/inmunología , Hepatocitos/inmunología , Separación Celular/métodos , Análisis de la Célula Individual/métodos , Ratones Endogámicos C57BL , Masculino , Linfocitos/inmunología , Linfocitos/citologíaRESUMEN
The pivotal role of DCs in initiating immune responses led to their use as vaccine vectors. However, the relationship between DC subsets involved in antigen presentation and the type of elicited immune responses underlined the need for the characterization of the DCs generated in vitro. The phenotypes of tissue-derived APCs from a cynomolgus macaque model for human vaccine development were compared with ex vivo-derived DCs. Monocyte/macrophages predominated in bone marrow (BM) and blood. Myeloid DCs (mDCs) were present in all tested tissues and were more highly represented than plasmacytoid DCs (pDCs). As in human skin, Langerhans cells (LCs) resided exclusively in the macaque epidermis, expressing CD11c, high levels of CD1a and langerin (CD207). Most DC subsets were endowed with tissue-specific combinations of PRRs. DCs generated from CD34(+) BM cells (CD34-DCs) were heterogeneous in phenotype. CD34-DCs shared properties (differentiation and PRR) of dermal and epidermal DCs. After injection into macaques, CD34-DCs expressing HIV-Gag induced Gag-specific CD4(+) and CD8(+) T cells producing IFN-γ, TNF-α, MIP-1ß, or IL-2. In high responding animals, the numbers of polyfunctional CD8(+) T cells increased with the number of booster injections. This DC-based vaccine strategy elicited immune responses relevant to the DC subsets generated in vitro.
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Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Activación de Linfocitos , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genética , Proteínas Adaptadoras Transductoras de Señales/biosíntesis , Animales , Presentación de Antígeno , Antígenos CD/biosíntesis , Antígenos CD1/biosíntesis , Antígenos CD34/genética , Células de la Médula Ósea , Antígeno CD11c/biosíntesis , Diferenciación Celular , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Lectinas Tipo C/biosíntesis , Macaca fascicularis/inmunología , Macrófagos , Masculino , Lectinas de Unión a Manosa/biosíntesis , ARN Mensajero/genética , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
BACKGROUND: Human polyomaviruses (HPyV) infections cause mostly unapparent or mild primary infections, followed by lifelong nonpathogenic persistence. HPyV, and specifically JCPyV, are known to co-diverge with their host, implying a slow rate of viral evolution and a large timescale of virus/host co-existence. Recent bio-informatic reports showed a large level of peptide homology between JCPyV and the human proteome. In this study, the antibody response to PyV peptides is evaluated. METHODS: The in-silico analysis of the HPyV proteome was followed by peptide microarray serology. A HPyV-peptide microarray containing 4,284 peptides was designed and covered 10 polyomavirus proteomes. Plasma samples from 49 healthy subjects were tested against these peptides. RESULTS: In-silico analysis of all possible HPyV 5-mer amino acid sequences were compared to the human proteome, and 1,609 unique motifs are presented. Assuming a linear epitope being as small as a pentapeptide, on average 9.3% of the polyomavirus proteome is unique and could be recognized by the host as non-self. Small t Ag (stAg) contains a significantly higher percentage of unique pentapeptides. Experimental evidence for the presence of antibodies against HPyV 15-mer peptides in healthy subjects resulted in the following observations: i) antibody responses against stAg were significantly elevated, and against viral protein 2 (VP2) significantly reduced; and ii) there was a significant correlation between the increasing number of embedded unique HPyV penta-peptides and the increase in microarray fluorescent signal. CONCLUSION: The anti-peptide HPyV-antibodies in healthy subjects are preferably directed against the penta-peptide derived unique fraction of the viral proteome.
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Anticuerpos Antivirales/sangre , Antígenos Virales/inmunología , Poliomavirus/inmunología , Adulto , Antígenos Virales/genética , ADN Viral/química , ADN Viral/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Poliomavirus/genética , Análisis por Matrices de Proteínas , Análisis de Secuencia de ADN , Estudios Seroepidemiológicos , Proteínas Virales/genética , Proteínas Virales/inmunología , Adulto JovenRESUMEN
The development of latency reversing agents that potently reactivate HIV without inducing global T cell activation would benefit the field of HIV reservoir research and could pave the way to a functional cure. Here, we explore the reactivation capacity of a lipid nanoparticle containing Tat mRNA (Tat-LNP) in CD4 T cells from people living with HIV undergoing antiretroviral therapy (ART). When combined with panobinostat, Tat-LNP induces latency reversal in a significantly higher proportion of latently infected cells compared to PMA/ionomycin (≈ 4-fold higher). We demonstrate that Tat-LNP does not alter the transcriptome of CD4 T cells, enabling the characterization of latently infected cells in their near-native state. Upon latency reversal, we identify transcriptomic differences between infected cells carrying an inducible provirus and non-infected cells (e.g. LINC02964, GZMA, CCL5). We confirm the transcriptomic differences at the protein level and provide evidence that the long non-coding RNA LINC02964 plays a role in active HIV infection. Furthermore, p24+ cells exhibit heightened PI3K/Akt signaling, along with downregulation of protein translation, suggesting that HIV-infected cells display distinct signatures facilitating their long-term persistence. Tat-LNP represents a valuable research tool for in vitro reservoir studies as it greatly facilitates the in-depth characterization of HIV reservoir cells' transcriptome and proteome profiles.
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Productos del Gen tat , VIH-1 , Nanopartículas , ARN Viral , Latencia del Virus , Latencia del Virus/efectos de los fármacos , Latencia del Virus/genética , Productos del Gen tat/genética , Productos del Gen tat/metabolismo , ARN Viral/administración & dosificación , ARN Viral/genética , ARN Viral/metabolismo , Nanopartículas/administración & dosificación , Nanopartículas/química , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , Infecciones por VIH/virología , Panobinostat/farmacología , Terapia Antirretroviral Altamente Activa , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/virología , Antígenos CD4/genética , Antígenos CD4/metabolismo , VIH-1/efectos de los fármacos , VIH-1/genética , Provirus/efectos de los fármacos , Provirus/genética , Análisis de Expresión Génica de una Sola Célula , Proteína p24 del Núcleo del VIH/genética , Proteína p24 del Núcleo del VIH/metabolismo , ARN Largo no Codificante/metabolismo , Células Cultivadas , Humanos , Ionomicina/farmacologíaRESUMEN
BACKGROUND: Suppression of HBV DNA, inhibition of HBV surface (HBsAg) production and therapeutic vaccination to reverse HBV-specific T-cell exhaustion in chronic HBV patients are likely required to achieve a functional cure. In the AAV-HBV mouse model, therapeutic vaccination can be effective in clearing HBV when HBsAg levels are low. Using a single-cell approach, we investigated the liver immune environment with different levels of HBsAg and sustained HBsAg loss through treatment with a GalNAc-HBV-siRNA followed by therapeutic vaccination. METHODS: AAV-HBV-transduced C57BL/6 mice were treated with GalNAc-HBV-siRNA to lower HBsAg levels and then vaccinated using a DNA vaccine. We used single-cell RNA and V(D)J sequencing to understand liver immune microenvironment changes. RESULTS: GalNAc-HBV-siRNA, followed by therapeutic vaccination, achieved sustained HBsAg loss in all mice. This was accompanied by CD4 follicular helper T-cell induction, polyclonal activation of CD8 T cells and clonal expansion of plasma cells that were responsible for antibody production. CONCLUSIONS: This study provides novel insights into liver immune changes at the single-cell level, highlighting the correlation between induced reduction of HBsAg levels and clonal expansion of CD4, CD8 T cells and plasma cells in the liver upon HBV siRNA and subsequent therapeutic vaccination.
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Immunotherapy aims to assist the natural immune system in achieving control over viral infection. Various immunotherapy formats have been evaluated in either therapy-naive or therapy-experienced HIV-infected patients over the last 20 years. These formats included non-antigen specific strategies such as cytokines that stimulate immunity or suppress the viral replication, as well as antibodies that block negative regulatory pathways. A number of HIV-specific therapeutic vaccinations have also been proposed, using in vivo injection of inactivated virus, plasmid DNA encoding HIV antigens, or recombinant viral vectors containing HIV genes. A specific format of therapeutic vaccines consists of ex vivo loading of autologous dendritic cells with one of the above mentioned antigenic formats or mRNA encoding HIV antigens.This review provides an extensive overview of the background and rationale of these different therapeutic attempts and discusses the results of trials in the SIV macaque model and in patients. To date success has been limited, which could be explained by insufficient quality or strength of the induced immune responses, incomplete coverage of HIV variability and/or inappropriate immune activation, with ensuing increased susceptibility of target cells.Future attempts at therapeutic vaccination should ideally be performed under the protection of highly active antiretroviral drugs in patients with a recovered immune system. Risks for immune escape should be limited by a better coverage of the HIV variability, using either conserved or mosaic sequences. Appropriate molecular adjuvants should be included to enhance the quality and strength of the responses, without inducing inappropriate immune activation. Finally, to achieve a long-lasting effect on viral control (i.e. a "functional cure") it is likely that these immune interventions should be combined with anti-latency drugs and/or gene therapy.
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Infecciones por VIH/terapia , VIH-1/inmunología , Inmunoterapia/métodos , Vacunas contra el SIDA/administración & dosificación , Animales , Antirretrovirales/administración & dosificación , Ensayos Clínicos como Asunto , Modelos Animales de Enfermedad , Infecciones por VIH/virología , Humanos , Macaca , Resultado del TratamientoRESUMEN
A variety of immune-based therapies has been developed in order to boost or induce protective CD8(+) T cell responses in order to control HIV replication. Since dendritic cells (DCs) are professional antigen-presenting cells (APCs) with the unique capability to stimulate naïve T cells into effector T cells, their use for the induction of HIV-specific immune responses has been studied intensively. In the present study we investigated whether modulation of the activation state of DCs electroporated with consensus codon-optimized HxB2 gag mRNA enhances their capacity to induce HIV gag-specific T cell responses. To this end, mature DCs were (i) co-electroporated with mRNA encoding interleukin (IL)-12p70 mRNA, or (ii) activated with a cytokine cocktail consisting of R848 and interferon (IFN)-γ. Our results confirm the ability of HxB2 gag-expressing DCs to expand functional HIV-specific CD8(+) T cells. However, although most of the patients had detectable gag-specific CD8(+) T cell responses, no significant differences in the level of expansion of functional CD8(+) T cells could be demonstrated when comparing conventional or immune-modulated DCs expressing IL-12p70. This result which goes against expectation may lead to a re-evaluation of the need for IL-12 expression by DCs in order to improve T-cell responses in HIV-1-infected individuals.
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Linfocitos T CD8-positivos/inmunología , Células Dendríticas/inmunología , Infecciones por VIH/inmunología , VIH-1 , Interleucina-12/metabolismo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Presentación de Antígeno , Células Dendríticas/metabolismo , Electroporación , Técnicas de Transferencia de Gen , Infecciones por VIH/metabolismo , Infecciones por VIH/terapia , VIH-1/inmunología , Humanos , Imidazoles/farmacología , Interferón gamma/farmacología , Interleucina-12/genética , Activación de Linfocitos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Polyelectrolyte microcapsules (MCs) are potent protein delivery vehicles which can be tailored with ligands to stimulate maturation of dendritic cells (DCs). We investigated the immune stimulatory capacity of monocyte-derived DC (Mo-DC) loaded with these MCs, containing p24 antigen from human immunodeficiency virus type 1 (HIV-1) alone [p24-containing MC (MCp24)] or with the Toll-like receptor ligand 3 (TLR3) ligand poly I:C (MCp24pIC) as a maturation factor. MO-DC, loaded with MCp24pIC, upregulated CCR7, CD80, CD83, and CD86 and produced high amounts of interleukin-12 (IL-12) cytokine, to a similar extent as MCp24 in the presence of an optimized cytokine cocktail. MO-DC from HIV-infected patients under highly active antiretroviral therapy (HAART) exposed to MCp24 together with cytokine cocktail or to MCp24pIC expanded autologous p24-specific CD4(+) and CD8(+) T-cell responses as measured by interferon-gamma (IFN-gamma) and IL-2 cytokine production and secretion. In vivo relevance was shown by immunizing C57BL/6 mice with MCp24pIC, which induced both humoral and cellular p24-specific immune responses. Together these data provide a proof of principle that both antigen and DC maturation signal can be delivered as a complex with polyelectrolyte capsules to stimulate virus-specific T cells both in vitro and in vivo. Polyelectrolyte MCs could be useful for in vivo immunization in HIV-1 and other infections.
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Células Dendríticas/inmunología , Portadores de Fármacos/química , Proteína p24 del Núcleo del VIH/inmunología , Poli I-C/inmunología , Polímeros/química , Animales , Femenino , Proteína p24 del Núcleo del VIH/química , VIH-1/inmunología , Humanos , Inmunidad Celular/inmunología , Inmunidad Humoral/inmunología , Interferón gamma/metabolismo , Interleucina-12/metabolismo , Interleucina-2/metabolismo , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Poli I-C/químicaRESUMEN
We describe two patients who did not experience a viral rebound after cessation of HAART which was initiated for progressive disease. CD4 T-cell count remained stable in one patient and progressively declined in the other, despite apparent viral control. We failed to identify any immune activation or genetic markers that could offer an explanation for this unusual "secondary controller" status. But their viruses are clearly less fit compared to viruses from rebounders.
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Despite the availability of an effective prophylactic vaccine for more than 30 years, nearly 300 million people worldwide are chronically infected with the hepatitis B virus (HBV), leading to 1 death every 30 s mainly from viral hepatitis-related cirrhosis and liver cancer. Chronic HBV patients exhibit weak, transient, or dysfunctional CD8+ T-cell responses to HBV, which contrasts with high CD8+ T-cell responses seen for resolvers of acute HBV infection. Therefore, a therapeutic DNA vaccine was designed, expressing both HBV core and polymerase proteins, and was sequence optimized to ensure high protein expression and secretion. Although the vaccine, administered intramuscularly via electroporation, had no effect on plasma viral parameters in a mouse model of persistent HBV infection, it did induce robust HBV-specific immune responses in healthy and adeno-associated hepatitis B virus (AAV-HBV) infected mice as well as in healthy non-human primates.
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Developing an immunotherapy to keep human immunodeficiency virus type 1 (HIV-1) replication suppressed while discontinuing highly active antiretroviral therapy (HAART) is an important challenge. In the present work, we evaluated in vitro whether dendritic cells (DC) electroporated with gag mRNA can induce HIV-specific responses in T cells from chronically infected subjects. Monocyte-derived DC, from therapy-naïve and HAART-treated HIV-1-seropositive subjects, that were electroporated with consensus codon-optimized HxB2 gag mRNA efficiently expanded T cells, secreting gamma interferon (IFN-gamma) and interleukin 2 (IL-2), as well as other cytokines and perforin, upon restimulation with a pool of overlapping Gag peptides. The functional expansion levels after 1 week of stimulation were comparable in T cells from HAART-treated and treatment-naïve patients and involved both CD4(+) and CD8(+) T cells, with evidence of bifunctionality in T cells. Epitope mapping of p24 showed that stimulated T cells had a broadened response toward previously nondescribed epitopes. DC, from HAART-treated subjects, that were electroporated with autologous proviral gag mRNA equally efficiently expanded HIV-specific T cells. Regulatory T cells did not prevent the induction of effector T cells in this system, whereas the blocking of PD-L1 slightly increased the induction of T-cell responses. This paper shows that DC, loaded with consensus or autologous gag mRNA, expand HIV-specific T-cell responses in vitro.
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Células Dendríticas/inmunología , Electroporación , VIH-1/inmunología , ARN Mensajero/genética , ARN Viral/genética , Linfocitos T/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Células Dendríticas/virología , Mapeo Epitopo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/genética , VIH-1/aislamiento & purificación , Humanos , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Perforina/biosíntesis , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Currently, there is an increasing interest to apply pre-fusion (pre-F) protein of respiratory syncytial virus (RSV) as antigen for the development of a subunit vaccine. A pre-F-containing powder would increase the flexibility regarding the route of administration. For instance, a pre-F-containing powder could be incorporated into a single-injection system releasing a primer, and after a lag time, a booster. The most challenging aspect, obtaining the booster after a lag time, may be achieved by incorporating the powder into a core encapsulated by a nonporous poly(dl-lactic-co-glycolic acid) (PLGA) shell. We intended to develop a stable freeze-dried pre-F-containing powder. Furthermore, we investigated whether incorporation of this powder into the core-shell implant was feasible and whether this system would induce a delayed RSV virus-neutralizing antibody (VNA) response in mice. The developed pre-F-containing powder, consisting of pre-F in a matrix of inulin, HEPES, sodium chloride, and Tween 80, was stable during freeze-drying and storage for at least 28 days at 60 °C. Incorporation of this powder into the core-shell implant was feasible and the core-shell production process did not affect the stability of pre-F. An in vitro release study showed that pre-F was incompletely released from the core-shell implant after a lag time of 4 weeks. The incomplete release may be the result of pre-F instability within the core-shell implant during the lag time and requires further research. Mice subcutaneously immunized with a pre-F-containing core-shell implant showed a delayed RSV VNA response that corresponded with pre-F release from the core-shell implant after a lag time of approximately 4 weeks. Moreover, pre-F-containing core-shell implants were able to boost RSV VNA titers of primed mice after a lag time of 4 weeks. These findings could contribute to the development of a single-injection pre-F-based vaccine containing a primer and a booster.
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A single-injection vaccine formulation that provides for both a prime and a boost immunization would have various advantages over a multiple-injection regime. For such a vaccine formulation, it is essential that the booster dose is released after a certain, preferably adjustable, lag time. In this study we investigated whether a core-shell based implant, containing ovalbumin as core material and poly(DL-lactic-co-glycolic acid) of various monomer ratios as shell material can be used to obtain such a booster release. An in vitro release study showed that the lag time after which the ovalbumin was released from the core-shell implant increased with increasing lactic to glycolic acid ratio of the polymer and ranged from 3-6 weeks. Fluorescence spectroscopy showed minimal differences between native ovalbumin and ovalbumin from core-shell implants that were incubated until just before the observed in vitro release. In addition, mice immunized with a subcutaneous inserted core-shell implant containing ovalbumin showed an ovalbumin-specific IgG1 antibody response after a lag time of 4 or 6-8 weeks. Moreover, delayed release of ovalbumin caused higher IgG1 antibody titers than conventional subcutaneous vaccination with ovalbumin dissolved in PBS. Collectively, these findings could contribute to the further development of a single-injection vaccine, making multiple injections of the vaccine superfluous.