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1.
Cell Rep ; 43(5): 114122, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38652659

RESUMEN

DNA sensing is important for antiviral immunity. The DNA sensor cGAS synthesizes 2'3'-cyclic GMP-AMP (cGAMP), a second messenger that activates STING, which induces innate immunity. cGAMP not only activates STING in the cell where it is produced but cGAMP also transfers to other cells. Transporters, channels, and pores (including SLC19A1, SLC46A2, P2X7, ABCC1, and volume-regulated anion channels (VRACs)) release cGAMP into the extracellular space and/or import cGAMP. We report that infection with multiple human viruses depletes some of these cGAMP conduits. This includes herpes simplex virus 1 (HSV-1) that targets SLC46A2, P2X7, and the VRAC subunits LRRC8A and LRRC8C for degradation. The HSV-1 protein UL56 is necessary and sufficient for these effects that are mediated at least partially by proteasomal turnover. UL56 thereby inhibits cGAMP uptake via VRAC, SLC46A2, and P2X7. Taken together, HSV-1 antagonizes intercellular cGAMP transfer. We propose that this limits innate immunity by reducing cell-to-cell communication via the immunotransmitter cGAMP.


Asunto(s)
Herpesvirus Humano 1 , Nucleótidos Cíclicos , Animales , Humanos , Células HEK293 , Herpes Simple/virología , Herpes Simple/metabolismo , Herpes Simple/inmunología , Herpesvirus Humano 1/fisiología , Nucleótidos Cíclicos/metabolismo , Proteínas Virales/metabolismo
2.
EMBO J ; 41(14): e109217, 2022 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-35670106

RESUMEN

Varicella-Zoster virus (VZV) causes chickenpox and shingles. Although the infection is associated with severe morbidity in some individuals, molecular mechanisms that determine innate immune responses remain poorly defined. We found that the cGAS/STING DNA sensing pathway was required for type I interferon (IFN) induction during VZV infection and that recognition of VZV by cGAS restricted its replication. Screening of a VZV ORF expression library identified the essential VZV tegument protein ORF9 as a cGAS antagonist. Ectopically or virally expressed ORF9 bound to endogenous cGAS leading to reduced type I IFN responses to transfected DNA. Confocal microscopy revealed co-localisation of cGAS and ORF9. ORF9 and cGAS also interacted directly in a cell-free system and phase-separated together with DNA. Furthermore, ORF9 inhibited cGAMP production by cGAS. Taken together, these results reveal the importance of the cGAS/STING DNA sensing pathway for VZV recognition and identify a VZV immune antagonist that partially but directly interferes with DNA sensing via cGAS.


Asunto(s)
Herpesvirus Humano 3 , Interferón Tipo I , Nucleotidiltransferasas , Proteínas Virales , ADN/metabolismo , Herpesvirus Humano 3/genética , Herpesvirus Humano 3/inmunología , Humanos , Inmunidad Innata , Interferón Tipo I/inmunología , Proteínas de la Membrana/inmunología , Nucleotidiltransferasas/antagonistas & inhibidores , Nucleotidiltransferasas/inmunología , Proteínas Virales/inmunología
3.
Mol Cell ; 81(20): 4109-4110, 2021 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-34686311

RESUMEN

Unusual nucleic acids activate innate immunity and may be present in transformed cells. Meng et al. (2021) find that cancer-associated mutations in NF2 turn this tumor suppressor into a potent antagonist of DNA- and RNA-induced innate immune signaling.


Asunto(s)
Interferones , Ácidos Nucleicos , Inmunidad Innata , ARN , Transducción de Señal
5.
Immunity ; 54(9): 1961-1975.e5, 2021 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-34525337

RESUMEN

Nucleic acids are powerful triggers of innate immunity and can adopt the Z-conformation, an unusual left-handed double helix. Here, we studied the biological function(s) of Z-RNA recognition by the adenosine deaminase ADAR1, mutations in which cause Aicardi-Goutières syndrome. Adar1mZα/mZα mice, bearing two point mutations in the Z-nucleic acid binding (Zα) domain that abolish Z-RNA binding, displayed spontaneous induction of type I interferons (IFNs) in multiple organs, including in the lung, where both stromal and hematopoietic cells showed IFN-stimulated gene (ISG) induction. Lung neutrophils expressed ISGs induced by the transcription factor IRF3, indicating an initiating role for neutrophils in this IFN response. The IFN response in Adar1mZα/mZα mice required the adaptor MAVS, implicating cytosolic RNA sensing. Adenosine-to-inosine changes were enriched in transposable elements and revealed a specific requirement of ADAR1's Zα domain in editing of a subset of RNAs. Thus, endogenous RNAs in Z-conformation have immunostimulatory potential curtailed by ADAR1, with relevance to autoinflammatory disease in humans.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/inmunología , Adenosina Desaminasa/genética , Interferón Tipo I/inmunología , ARN Bicatenario/genética , Adenosina/genética , Adenosina/metabolismo , Animales , Enfermedades Autoinmunes del Sistema Nervioso/genética , Enfermedades Autoinmunes del Sistema Nervioso/inmunología , Inosina/genética , Inosina/metabolismo , Interferón Tipo I/genética , Ratones , Mutación , Malformaciones del Sistema Nervioso/genética , Malformaciones del Sistema Nervioso/inmunología , Edición de ARN/genética , ARN Bicatenario/metabolismo
6.
Sci Rep ; 11(1): 13638, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34211037

RESUMEN

Human cells respond to infection by SARS-CoV-2, the virus that causes COVID-19, by producing cytokines including type I and III interferons (IFNs) and proinflammatory factors such as IL6 and TNF. IFNs can limit SARS-CoV-2 replication but cytokine imbalance contributes to severe COVID-19. We studied how cells detect SARS-CoV-2 infection. We report that the cytosolic RNA sensor MDA5 was required for type I and III IFN induction in the lung cancer cell line Calu-3 upon SARS-CoV-2 infection. Type I and III IFN induction further required MAVS and IRF3. In contrast, induction of IL6 and TNF was independent of the MDA5-MAVS-IRF3 axis in this setting. We further found that SARS-CoV-2 infection inhibited the ability of cells to respond to IFNs. In sum, we identified MDA5 as a cellular sensor for SARS-CoV-2 infection that induced type I and III IFNs.


Asunto(s)
COVID-19/inmunología , Interferón Tipo I/inmunología , Helicasa Inducida por Interferón IFIH1/inmunología , Interferones/inmunología , SARS-CoV-2/inmunología , Línea Celular , Humanos , Inmunidad Innata , ARN/inmunología , Interferón lambda
7.
Nat Cell Biol ; 23(7): 704-717, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34253898

RESUMEN

Haematopoietic stem cells (HSCs) are normally quiescent, but have evolved mechanisms to respond to stress. Here, we evaluate haematopoietic regeneration induced by chemotherapy. We detect robust chromatin reorganization followed by increased transcription of transposable elements (TEs) during early recovery. TE transcripts bind to and activate the innate immune receptor melanoma differentiation-associated protein 5 (MDA5) that generates an inflammatory response that is necessary for HSCs to exit quiescence. HSCs that lack MDA5 exhibit an impaired inflammatory response after chemotherapy and retain their quiescence, with consequent better long-term repopulation capacity. We show that the overexpression of ERV and LINE superfamily TE copies in wild-type HSCs, but not in Mda5-/- HSCs, results in their cycling. By contrast, after knockdown of LINE1 family copies, HSCs retain their quiescence. Our results show that TE transcripts act as ligands that activate MDA5 during haematopoietic regeneration, thereby enabling HSCs to mount an inflammatory response necessary for their exit from quiescence.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Elementos Transponibles de ADN , Hematopoyesis/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Helicasa Inducida por Interferón IFIH1/metabolismo , Agonistas Mieloablativos/farmacología , Animales , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Retrovirus Endógenos/genética , Activación Enzimática , Células HEK293 , Células Madre Hematopoyéticas/enzimología , Humanos , Helicasa Inducida por Interferón IFIH1/genética , Ligandos , Elementos de Nucleótido Esparcido Largo , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal
8.
EMBO Rep ; 22(8): e52447, 2021 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-34142428

RESUMEN

Cyclic GMP-AMP (cGAMP) is an immunostimulatory molecule produced by cGAS that activates STING. cGAMP is an adjuvant when administered alongside antigens. cGAMP is also incorporated into enveloped virus particles during budding. Here, we investigate whether inclusion of cGAMP within viral vaccine vectors enhances their immunogenicity. We immunise mice with virus-like particles (VLPs) containing HIV-1 Gag and the vesicular stomatitis virus envelope glycoprotein G (VSV-G). cGAMP loading of VLPs augments CD4 and CD8 T-cell responses. It also increases VLP- and VSV-G-specific antibody titres in a STING-dependent manner and enhances virus neutralisation, accompanied by increased numbers of T follicular helper cells. Vaccination with cGAMP-loaded VLPs containing haemagglutinin induces high titres of influenza A virus neutralising antibodies and confers protection upon virus challenge. This requires cGAMP inclusion within VLPs and is achieved at markedly reduced cGAMP doses. Similarly, cGAMP loading of VLPs containing the SARS-CoV-2 Spike protein enhances Spike-specific antibody titres. cGAMP-loaded VLPs are thus an attractive platform for vaccination.


Asunto(s)
COVID-19 , Vacunas contra la Influenza , Vacunas de Partículas Similares a Virus , Animales , Humanos , Ratones , Nucleótidos Cíclicos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Vacunas de Partículas Similares a Virus/genética
9.
Cells ; 9(6)2020 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-32560274

RESUMEN

The Zika virus (ZIKV) has received much attention due to an alarming increase in cases of neurological disorders including congenital Zika syndrome associated with infection. To date, there is no effective treatment available. An immediate response by the innate immune system is crucial for effective control of the virus. Using CRISPR/Cas9-mediated knockouts in A549 cells, we investigated the individual contributions of the RIG-I-like receptors MDA5 and RIG-I to ZIKV sensing and control of this virus by using a Brazilian ZIKV strain. We show that RIG-I is the main sensor for ZIKV in A549 cells. Surprisingly, we observed that loss of RIG-I and consecutive type I interferon (IFN) production led to virus-induced apoptosis. ZIKV non-structural protein NS5 was reported to interfere with type I IFN receptor signaling. Additionally, we show that ZIKV NS5 inhibits type I IFN induction. Overall, our study highlights the importance of RIG-I-dependent ZIKV sensing for the prevention of virus-induced cell death and shows that NS5 inhibits the production of type I IFN.


Asunto(s)
Muerte Celular/fisiología , Proteína 58 DEAD Box/metabolismo , Receptores Inmunológicos/metabolismo , Infección por el Virus Zika/virología , Animales , Chlorocebus aethiops/virología , Humanos , Inmunidad Innata/inmunología , Transducción de Señal/inmunología , Células Vero/virología , Proteínas no Estructurales Virales/metabolismo , Virus Zika/inmunología , Virus Zika/metabolismo , Infección por el Virus Zika/inmunología
10.
Cell Rep ; 31(6): 107640, 2020 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-32402273

RESUMEN

The anti-leukemia agent forodesine causes cytotoxic overload of intracellular deoxyguanosine triphosphate (dGTP) but is efficacious only in a subset of patients. We report that SAMHD1, a phosphohydrolase degrading deoxyribonucleoside triphosphate (dNTP), protects cells against the effects of dNTP imbalances. SAMHD1-deficient cells induce intrinsic apoptosis upon provision of deoxyribonucleosides, particularly deoxyguanosine (dG). Moreover, dG and forodesine act synergistically to kill cells lacking SAMHD1. Using mass cytometry, we find that these compounds kill SAMHD1-deficient malignant cells in patients with chronic lymphocytic leukemia (CLL). Normal cells and CLL cells from patients without SAMHD1 mutation are unaffected. We therefore propose to use forodesine as a precision medicine for leukemia, stratifying patients by SAMHD1 genotype or expression.


Asunto(s)
Nucleótidos de Desoxiguanina/metabolismo , Nucleósidos de Purina/farmacología , Pirimidinonas/farmacología , Proteína 1 que Contiene Dominios SAM y HD/metabolismo , Animales , Resistencia a Antineoplásicos , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos C57BL
11.
Eur J Immunol ; 50(1): 56-62, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31608988

RESUMEN

Toll-like receptor 7 (TLR7) is an innate immune sensor for single-strand RNA (ssRNA). Recent structural analysis revealed that TLR7 has an additional binding site for nucleosides such as guanosine, and is activated when both guanosine and ssRNA bind. The nucleoside binding site also accommodates imidazoquinoline derivatives such as R848, which activate TLR7 in the absence of ssRNA. Here, we report that deoxyguanosine (dG) triggered cytokine production in murine bone marrow derived macrophages and plasmacytoid dendritic cells, as well as in human peripheral blood mononuclear cells, including type I interferons and pro-inflammatory factors such as TNF and IL-6. This signalling activity of dG was dependent on TLR7 and its adaptor MyD88 and did not require amplification via the type I interferon receptor. dG-triggered cytokine production required endosomal maturation but did not depend on the concurrent provision of RNA. We conclude that dG induces an inflammatory response through TLR7 and propose that dG is an RNA-independent TLR7 agonist.


Asunto(s)
Desoxiguanosina/inmunología , Inflamación/inmunología , Receptor Toll-Like 7/agonistas , Animales , Desoxiguanosina/metabolismo , Humanos , Inflamación/metabolismo , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL
13.
Nat Cell Biol ; 19(9): 1061-1070, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28759028

RESUMEN

Cellular senescence is triggered by various distinct stresses and characterized by a permanent cell cycle arrest. Senescent cells secrete a variety of inflammatory factors, collectively referred to as the senescence-associated secretory phenotype (SASP). The mechanism(s) underlying the regulation of the SASP remains incompletely understood. Here we define a role for innate DNA sensing in the regulation of senescence and the SASP. We find that cyclic GMP-AMP synthase (cGAS) recognizes cytosolic chromatin fragments in senescent cells. The activation of cGAS, in turn, triggers the production of SASP factors via stimulator of interferon genes (STING), thereby promoting paracrine senescence. We demonstrate that diverse stimuli of cellular senescence engage the cGAS-STING pathway in vitro and we show cGAS-dependent regulation of senescence following irradiation and oncogene activation in vivo. Our findings provide insights into the mechanisms underlying cellular senescence by establishing the cGAS-STING pathway as a crucial regulator of senescence and the SASP.


Asunto(s)
Senescencia Celular , Cromatina/enzimología , Citosol/enzimología , Inmunidad Innata , Nucleotidiltransferasas/metabolismo , Animales , Proliferación Celular , Células Cultivadas , Senescencia Celular/efectos de la radiación , Cromatina/inmunología , Cromatina/efectos de la radiación , Citosol/inmunología , Citosol/efectos de la radiación , Activación Enzimática , Femenino , Genotipo , Inmunidad Innata/efectos de la radiación , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/inmunología , Estrés Oxidativo , Comunicación Paracrina , Fenotipo , Interferencia de ARN , Transducción de Señal , Factores de Tiempo , Transfección
14.
Methods Mol Biol ; 1656: 143-152, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28808967

RESUMEN

Sensing of cytoplasmic DNA by cGAS is essential for the initiation of immune responses against several viruses. cGAS also plays important roles in some autoinflammatory and autoimmune diseases and may be involved in immune responses targeting cancer cells. Once activated, cGAS catalyzes the formation of the di-nucleotide 2'-3'-cyclic GMP-AMP (cGAMP), which propagates a signaling cascade leading to the production of type I interferons (IFNs). Interestingly, cGAMP is incorporated into enveloped viruses and is transferred to newly infected cells by virions. In this article, we describe a method to purify cGAMP from viral particles and a bioassay to measure its activity. This assay takes advantage of a reporter cell line that expresses the genes encoding green fluorescent protein (GFP) and firefly luciferase under the control of the IFNß promoter, allowing the testing of several samples in a single experiment taking not more than 3 days.


Asunto(s)
Interferón beta/inmunología , Nucleótidos Cíclicos , Virión , Virus , Humanos , Inmunidad Innata , Nucleótidos Cíclicos/inmunología , Nucleótidos Cíclicos/aislamiento & purificación , Células THP-1 , Virión/química , Virión/inmunología , Virosis/inmunología , Virus/química , Virus/inmunología
15.
EMBO J ; 36(17): 2529-2543, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28716805

RESUMEN

Nucleic acids are potent triggers for innate immunity. Double-stranded DNA and RNA adopt different helical conformations, including the unusual Z-conformation. Z-DNA/RNA is recognised by Z-binding domains (ZBDs), which are present in proteins implicated in antiviral immunity. These include ZBP1 (also known as DAI or DLM-1), which induces necroptosis, an inflammatory form of cell death. Using reconstitution and knock-in models, we report that mutation of key amino acids involved in Z-DNA/RNA binding in ZBP1's ZBDs prevented necroptosis upon infection with mouse cytomegalovirus. Induction of cell death was cell autonomous and required RNA synthesis but not viral DNA replication. Accordingly, ZBP1 directly bound to RNA via its ZBDs. Intact ZBP1-ZBDs were also required for necroptosis triggered by ectopic expression of ZBP1 and caspase blockade, and ZBP1 cross-linked to endogenous RNA These observations show that Z-RNA may constitute a molecular pattern that induces inflammatory cell death upon sensing by ZBP1.


Asunto(s)
Apoptosis/fisiología , Glicoproteínas/metabolismo , ARN/metabolismo , Animales , Citomegalovirus/genética , Infecciones por Citomegalovirus/metabolismo , Glicoproteínas/genética , Ratones , Ratones Transgénicos , Células 3T3 NIH , Conformación de Ácido Nucleico , ARN/química , Proteínas de Unión al ARN
16.
Cell Rep ; 16(6): 1492-1501, 2016 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-27477283

RESUMEN

SAMHD1 is a restriction factor for HIV-1 infection. SAMHD1 mutations cause the autoinflammatory Aicardi-Goutières syndrome that is characterized by chronic type I interferon (IFN) secretion. We show that the spontaneous IFN response in SAMHD1-deficient cells and mice requires the cGAS/STING cytosolic DNA-sensing pathway. We provide genetic evidence that cell-autonomous control of lentivirus infection in myeloid cells by SAMHD1 limits virus-induced production of IFNs and the induction of co-stimulatory markers. This program of myeloid cell activation required reverse transcription, cGAS and STING, and signaling through the IFN receptor. Furthermore, SAMHD1 reduced the induction of virus-specific cytotoxic T cells in vivo. Therefore, virus restriction by SAMHD1 limits the magnitude of IFN and T cell responses. This demonstrates a competition between cell-autonomous virus control and subsequent innate and adaptive immune responses, a concept with important implications for the treatment of infection.


Asunto(s)
Inmunidad Adaptativa/inmunología , VIH-1/inmunología , Inmunidad Innata/inmunología , Proteínas de la Membrana/metabolismo , Nucleotidiltransferasas/metabolismo , Proteína 1 que Contiene Dominios SAM y HD/metabolismo , Animales , Células Dendríticas/inmunología , Infecciones por VIH/metabolismo , VIH-1/genética , Interferón beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteína 1 que Contiene Dominios SAM y HD/deficiencia , Replicación Viral/inmunología
17.
Hum Vaccin Immunother ; 11(4): 1030-5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25751015

RESUMEN

Viral vector vaccines designed to elicit CD8(+) T cells in non-human primates exert potent control of immunodeficiency virus infections; however, similar approaches have been unsuccessful in humans. Adenoviral vectors elicit potent T cell responses but also induce production of immunosuppressive interleukin-10 (IL-10), which can limit the expansion of T cell responses. We investigated whether inhibiting IL-10 signaling prior to immunization with a candidate adenovirus vectored-HIV-1 vaccine, ChAdV63.HIVconsv, could modulate innate and adaptive immune responses in BALB/c mice. Transient IL-10 receptor blockade led to a modest but significant increase in the total magnitude CD8(+) T cell response to HIVconsv, but did not affect T cell responses to immunodominant epitopes. Anti-IL-10R-treated animals also exhibited greater expression of CD86 on CD11c(+) dendritic cells. Our data support further investigation and optimization of IL-10 blocking strategies to improve the immunogenicity of vaccines based on replication-defective adenoviruses.


Asunto(s)
Adenovirus de los Simios/genética , Linfocitos T CD8-positivos/inmunología , Vectores Genéticos/genética , VIH-1/inmunología , Receptores de Interleucina-10/antagonistas & inhibidores , Vacunas contra el SIDA , Animales , Antígeno B7-2/metabolismo , Antígeno CD11c/metabolismo , Ensayo de Immunospot Ligado a Enzimas , Femenino , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1/metabolismo , Ratones , Ratones Endogámicos BALB C
18.
Clin Vaccine Immunol ; 21(11): 1565-72, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25230940

RESUMEN

A likely requirement for a protective vaccine against human immunodeficiency virus type 1 (HIV-1)/AIDS is, in addition to eliciting antibody responses, induction of effective T cells. To tackle HIV-1 diversity by T-cell vaccines, we designed an immunogen, HIVconsv, derived from the most functionally conserved regions of the HIV-1 proteome and demonstrated its high immunogenicity in humans and rhesus macaques when delivered by regimens combining plasmid DNA, nonreplicating simian (chimpanzee) adenovirus ChAdV-63, and nonreplicating modified vaccinia virus Ankara (MVA) as vectors. Here, we aimed to increase the decision power for iterative improvements of this vaccine strategy in the BALB/c mouse model. First, we found that prolonging the period after the ChAdV63.HIVconsv prime up to 6 weeks increased the frequencies of HIV-1-specific, gamma interferon (IFN-γ)-producing T cells induced by the MVA.HIVconsv boost. Induction of strong responses allowed us to map comprehensively the H-2(d)-restricted T-cell responses to these regions and identified 8 HIVconsv peptides, of which three did not contain a previously described epitope and were therefore considered novel. Induced effector T cells were oligofunctional and lysed sensitized targets in vitro. Our study therefore provides additional tools for studying and optimizing vaccine regimens in this commonly used small animal model, which will in turn guide vaccine improvements in more expensive nonhuman primate and human clinical trials.


Asunto(s)
Vacunas contra el SIDA/inmunología , Secuencia Conservada/inmunología , VIH-1/inmunología , Interferón gamma/metabolismo , Linfocitos T/inmunología , Proteínas Virales/inmunología , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/aislamiento & purificación , Adenoviridae/genética , Animales , Portadores de Fármacos , Epítopos de Linfocito T/administración & dosificación , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Femenino , Vectores Genéticos , Ratones Endogámicos BALB C , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Virus Vaccinia/genética
19.
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
20.
EMBO J ; 32(18): 2454-62, 2013 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-23872947

RESUMEN

SAMHD1 is a host restriction factor for human immunodeficiency virus 1 (HIV-1) in cultured human cells. SAMHD1 mutations cause autoimmune Aicardi-Goutières syndrome and are found in cancers including chronic lymphocytic leukaemia. SAMHD1 is a triphosphohydrolase that depletes the cellular pool of deoxynucleoside triphosphates, thereby preventing reverse transcription of retroviral genomes. However, in vivo evidence for SAMHD1's antiviral activity has been lacking. We generated Samhd1 null mice that do not develop autoimmune disease despite displaying a type I interferon signature in spleen, macrophages and fibroblasts. Samhd1(-/-) cells have elevated deoxynucleoside triphosphate (dNTP) levels but, surprisingly, SAMHD1 deficiency did not lead to increased infection with VSV-G-pseudotyped HIV-1 vectors. The lack of restriction is likely attributable to the fact that dNTP concentrations in SAMHD1-sufficient mouse cells are higher than the KM of HIV-1 reverse transcriptase (RT). Consistent with this notion, an HIV-1 vector mutant bearing an RT with lower affinity for dNTPs was sensitive to SAMHD1-dependent restriction in cultured cells and in mice. This shows that SAMHD1 can restrict lentiviruses in vivo and that nucleotide starvation is an evolutionarily conserved antiviral mechanism.


Asunto(s)
Enfermedades Autoinmunes del Sistema Nervioso/metabolismo , Infecciones por VIH/fisiopatología , VIH-1/fisiología , Proteínas de Unión al GTP Monoméricas/metabolismo , Malformaciones del Sistema Nervioso/metabolismo , Transcripción Reversa/fisiología , Animales , Enfermedades Autoinmunes del Sistema Nervioso/genética , Línea Celular , Vectores Genéticos/genética , Infecciones por VIH/genética , Transcriptasa Inversa del VIH/metabolismo , VIH-1/enzimología , Interferón Tipo I/metabolismo , Ratones , Ratones Noqueados , Proteínas de Unión al GTP Monoméricas/genética , Malformaciones del Sistema Nervioso/genética , Nucleótidos/metabolismo , Transcripción Reversa/genética , Proteína 1 que Contiene Dominios SAM y HD
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