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1.
J Thorac Oncol ; 15(5): 827-842, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31945495

RESUMO

INTRODUCTION: Oncolytic immunotherapy is based on the use of nonpathogenic replicative oncolytic viruses that infect and kill tumor cells exclusively. Recently, we found that the spontaneous oncolytic activity of the Schwarz strain of measles virus (MV) against human malignant pleural mesothelioma (MPM) depends on defects in the antiviral type I interferon (IFN-I) response in tumor cells. METHODS: In this study, we studied three independent human MPM bio-collections to identify the defects in the IFN-I responses in tumor cells. RESULTS: We show that the most frequent defect is the homozygous deletions (HDs) of all the 14 IFN-I genes (IFN-α and IFN-ß) that we found in more than half of MV-sensitive MPM cell lines. These HDs occur together with the HDs of the tumor suppressor gene CDKN2A also located in the 9p21.3 chromosome region. Therefore, the IFN-I-/- MPM cell lines develop a partial and weak IFN-I response when they are exposed to the virus compared with that of normal cells and MV-resistant MPM cell lines. This response consists of the expression of a restricted number of IFN-stimulated genes that do not depend on the presence of IFN-I. In addition, the IFN-I-/- MPM cell lines infected by MV also develop a pro-inflammatory response associated with stress of the endoplasmic reticulum. CONCLUSION: Our study emphasizes the link between HDs of IFN-I encoding genes and the CDKN2A gene in MPM and sensitivity to MV oncolytic immunotherapy.

2.
Methods Mol Biol ; 2058: 127-132, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31486035

RESUMO

Oncolytic immunotherapy efficacy relies partially on the induction of immunogenic tumor cell death following infection with oncolytic viruses (OV) to induce an antitumor immune response. Here, we describe a method to determine if an OV is able to induce such an immunogenic tumor cell death. This method consists in testing whether tumor cells lysed by an OV are able to induce the maturation of human monocyte-derived immature dendritic cells (Mo-iDC).

3.
Sci Rep ; 9(1): 20134, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882812

RESUMO

T. capitatus is widely used in traditional medicine in Tunisia. The main goal of this study was to evaluate the phytochemical composition, the fatty acids profile, the antioxidant, antibacterial, and antifungal activities as well as the cytotoxic potential of the essential oil (EO) of this plant. The identification and the quantification of the different constituents of the tested EO was determined by gas chromatography-mass spectrometry (GC-MS). Antioxidant activities were evaluated by spectrophotometric methods and chemical tests. HCT 116 cells were used to evaluate the cytotoxic effect of the EO. The microdilution method was conducted to evaluate the antibacterial activity. Poisoned food method was used to test the antifungal activities against fungi species such Aspergillus niger and Aspergillus flavus. The EO presented several components, mainly monoterpenes. Results revealed that T. capitatus EO is not cytotoxic and showed excellent antioxidant activity with a dose dependent manner. Regarding antimicrobial activity, T. capitatus EO was efficient against all tested bacteria and fungi.

4.
Cell Host Microbe ; 26(6): 823-835.e11, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31761719

RESUMO

RNA-binding proteins (RBPs) perform key cellular activities by controlling the function of bound RNAs. The widely held assumption that RBPs are strictly intracellular has been challenged by the discovery of secreted RBPs. However, extracellular RBPs have been described in eukaryotes, while secreted bacterial RBPs have not been reported. Here, we show that the bacterial pathogen Listeria monocytogenes secretes a small RBP that we named Zea. We show that Zea binds a subset of L. monocytogenes RNAs, causing their accumulation in the extracellular medium. Furthermore, during L. monocytogenes infection, Zea binds RIG-I, the non-self-RNA innate immunity sensor, potentiating interferon-ß production. Mouse infection studies reveal that Zea affects L. monocytogenes virulence. Together, our results unveil that bacterial RNAs can be present extracellularly in association with RBPs, acting as "social RNAs" to trigger a host response during infection.


Assuntos
Proteína DEAD-box 58/metabolismo , Listeria monocytogenes/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Proteína DEAD-box 58/imunologia , Células HEK293 , Interações entre Hospedeiro e Microrganismos , Humanos , Imunidade Inata , Interferon beta/metabolismo , Listeria monocytogenes/imunologia , Listeria monocytogenes/patogenicidade , Camundongos , RNA Bacteriano/metabolismo , Transdução de Sinais/imunologia , Virulência/imunologia
5.
Sci Transl Med ; 11(512)2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578242

RESUMO

Lassa fever is a major threat in Western Africa. The large number of people living at risk for this disease calls for the development of a vaccine against Lassa virus (LASV). We generated live-attenuated LASV vaccines based on measles virus and Mopeia virus platforms and expressing different LASV antigens, with the aim to develop a vaccine able to protect after a single shot. We compared the efficacy of these vaccines against LASV in cynomolgus monkeys. The vaccines were well tolerated and protected the animals from LASV infection and disease after a single immunization but with varying efficacy. Analysis of the immune responses showed that complete protection was associated with robust secondary T cell and antibody responses against LASV. Transcriptomic and proteomic analyses showed an early activation of innate immunity and T cell priming after immunization with the most effective vaccines, with changes detectable as early as 2 days after immunization. The most efficacious vaccine candidate, a measles vector simultaneously expressing LASV glycoprotein and nucleoprotein, has been selected for further clinical evaluation.

6.
Sci Signal ; 12(601)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31575732

RESUMO

The retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) RIG-I, MDA5, and LGP2 stimulate inflammatory and antiviral responses by sensing nonself RNA molecules produced during viral replication. Here, we investigated how LGP2 regulates the RIG-I- and MDA5-dependent induction of type I interferon (IFN) signaling and showed that LGP2 interacted with different components of the RNA-silencing machinery. We identified a direct protein-protein interaction between LGP2 and the IFN-inducible, double-stranded RNA binding protein PACT. The LGP2-PACT interaction was mediated by the regulatory C-terminal domain of LGP2 and was necessary for inhibiting RIG-I-dependent responses and for amplifying MDA5-dependent responses. We described a point mutation within LGP2 that disrupted the LGP2-PACT interaction and led to the loss of LGP2-mediated regulation of RIG-I and MDA5 signaling. These results suggest a model in which the LGP2-PACT interaction regulates the inflammatory responses mediated by RIG-I and MDA5 and enables the cellular RNA-silencing machinery to coordinate with the innate immune response.

7.
PLoS Negl Trop Dis ; 13(8): e0007299, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31412040

RESUMO

BACKGROUND: To be transmitted to vertebrate hosts via the saliva of their vectors, arthropod-borne viruses have to cross several barriers in the mosquito body, including the midgut infection and escape barriers. Yellow fever virus (YFV) belongs to the genus Flavivirus, which includes human viruses transmitted by Aedes mosquitoes, such as dengue and Zika viruses. The live-attenuated YFV-17D vaccine has been used safely and efficiently on a large scale since the end of World War II. Early studies have shown, using viral titration from salivary glands of infected mosquitoes, that YFV-17D can infect Aedes aegypti midgut, but does not disseminate to other tissues. METHODOLOGY/PRINCIPAL FINDINGS: Here, we re-visited this issue using a panel of techniques, such as RT-qPCR, Western blot, immunofluorescence and titration assays. We showed that YFV-17D replication was not efficient in Aedes aegypti midgut, as compared to the clinical isolate YFV-Dakar. Viruses that replicated in the midgut failed to disseminate to secondary organs. When injected into the thorax of mosquitoes, viruses succeeded in replicating into midgut-associated tissues, suggesting that, during natural infection, the block for YFV-17D replication occurs at the basal membrane of the midgut. CONCLUSIONS/SIGNIFICANCE: The two barriers associated with Ae. aegypti midgut prevent YFV-17D replication. Our study contributes to our basic understanding of vector-pathogen interactions and may also aid in the development of non-transmissible live virus vaccines.


Assuntos
Aedes/virologia , Trato Gastrointestinal/virologia , Replicação Viral/efeitos dos fármacos , Vacina contra Febre Amarela/farmacologia , Vírus da Febre Amarela/efeitos dos fármacos , Vírus da Febre Amarela/crescimento & desenvolvimento , Animais , Linhagem Celular , Trato Gastrointestinal/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Mosquitos Vetores , Glândulas Salivares , Vacinas Atenuadas , Carga Viral , Vírus da Febre Amarela/genética
8.
Viruses ; 11(3)2019 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-30909570

RESUMO

Lassa virus (LASV) and Mopeia virus (MOPV) are two closely related Old-World mammarenaviruses. LASV causes severe hemorrhagic fever with high mortality in humans, whereas no case of MOPV infection has been reported. Comparing MOPV and LASV is a powerful strategy to unravel pathogenic mechanisms that occur during the course of pathogenic arenavirus infection. We used a yeast two-hybrid approach to identify cell partners of MOPV and LASV Z matrix protein in which two autophagy adaptors were identified, NDP52 and TAX1BP1. Autophagy has emerged as an important cellular defense mechanism against viral infections but its role during arenavirus infection has not been shown. Here, we demonstrate that autophagy is transiently induced by MOPV, but not LASV, in infected cells two days after infection. Impairment of the early steps of autophagy significantly decreased the production of MOPV and LASV infectious particles, whereas a blockade of the degradative steps impaired only MOPV infectious particle production. Our study provides insights into the role played by autophagy during MOPV and LASV infection and suggests that this process could partially explain their different pathogenicity.


Assuntos
Arenavirus/fisiologia , Autofagia , Vírus Lassa/fisiologia , Animais , Arenavirus/patogenicidade , Chlorocebus aethiops , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Vírus Lassa/patogenicidade , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Técnicas do Sistema de Duplo-Híbrido , Células Vero
9.
NPJ Vaccines ; 4: 12, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30820355

RESUMO

Following the RTS,S malaria vaccine, which showed only partial protection with short-term memory, there is strong support to develop second-generation malaria vaccines that yield higher efficacy with longer duration. The use of replicating viral vectors to deliver subunit vaccines is of great interest due to their capacity to induce efficient cellular immune responses and long-term memory. The measles vaccine virus offers an efficient and safe live viral vector that could easily be implemented in the field. Here, we produced recombinant measles viruses (rMV) expressing malaria "gold standard" circumsporozoïte antigen (CS) of Plasmodium berghei (Pb) and Plasmodium falciparum (Pf) to test proof of concept of this delivery strategy. Immunization with rMV expressing PbCS or PfCS induced high antibody responses in mice that did not decrease for at least 22 weeks post-prime, as well as rapid development of cellular immune responses. The observed long-term memory response is key for development of second-generation malaria vaccines. Sterile protection was achieved in 33% of immunized mice, as usually observed with the CS antigen, and all other immunized animals were clinically protected from severe and lethal Pb ANKA-induced cerebral malaria. Further rMV-vectored malaria vaccine candidates expressing additional pre-erythrocytic and blood-stage antigens in combination with rMV expressing PfCS may provide a path to development of next generation malaria vaccines with higher efficacy.

10.
Front Immunol ; 10: 134, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30809223

RESUMO

The guanabenz derivative Sephin1 has recently been proposed to increase the levels of translation initiation factor 2 (eIF2α) phosphorylation by inhibiting dephosphorylation by the protein phosphatase 1-GADD34 (PPP1R15A) complex. As phosphorylation of eIF2α by protein kinase R (PKR) is a prominent cellular antiviral pathway, we evaluated the consequences of Sephin1 treatment on virus replication. Our results provide evidence that Sephin1 downregulates replication of human respiratory syncytial virus, measles virus, human adenovirus 5 virus, human enterovirus D68, human cytomegalovirus, and rabbit myxoma virus. However, Sephin1 proved to be inactive against influenza virus, as well as against Japanese encephalitis virus. Sephin1 increased the levels of phosphorylated eIF2α in cells exposed to a PKR agonist. By contrast, in virus-infected cells, the levels of phosphorylated eIF2α did not always correlate with the inhibition of virus replication by Sephin1. This work identifies Sephin1 as an antiviral molecule in cell culture against RNA, as well as DNA viruses belonging to phylogenetically distant families.


Assuntos
Antivirais/farmacologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Guanabenzo/análogos & derivados , Animais , Antivirais/uso terapêutico , Linhagem Celular , Vírus de DNA/efeitos dos fármacos , Vírus de DNA/fisiologia , Guanabenzo/farmacologia , Guanabenzo/uso terapêutico , Humanos , Camundongos , Fosforilação/efeitos dos fármacos , Infecções por Poxviridae/tratamento farmacológico , Vírus de RNA/efeitos dos fármacos , Vírus de RNA/fisiologia , Coelhos , Infecções Tumorais por Vírus/tratamento farmacológico , Replicação Viral/efeitos dos fármacos
11.
Cancer Immunol Immunother ; 68(4): 533-544, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30656384

RESUMO

Cancer immunotherapy is seeing an increasing focus on vaccination with tumor-associated antigens (TAAs). Human telomerase (hTERT) is a TAA expressed by most tumors to overcome telomere shortening. Tolerance to hTERT can be easily broken both naturally and experimentally and hTERT DNA vaccine candidates have been introduced in clinical trials. DNA prime/boost strategies have been widely developed to immunize efficiently against infectious diseases. We explored the use of a recombinant measles virus (MV) hTERT vector to boost DNA priming as recombinant live attenuated measles virus has an impressive safety and efficacy record. Here, we show that a MV-TERT vector can rapidly and strongly boost DNA hTERT priming in MV susceptible IFNAR/CD46 mouse models. The cellular immune responses were Th1 polarized. No humoral responses were elicited. The 4 kb hTERT transgene did not impact MV replication or induction of cell-mediated responses. These findings validate the MV-TERT vector to boost cell-mediated responses following DNA priming in humans.


Assuntos
Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/imunologia , Vetores Genéticos , Imunidade Celular , Vírus do Sarampo , Linfócitos T/imunologia , Telomerase/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Vacinas Anticâncer/genética , Linhagem Celular , Chlorocebus aethiops , Citocinas/metabolismo , Citotoxicidade Imunológica , Vetores Genéticos/genética , Humanos , Imunização , Imunização Secundária , Vírus do Sarampo/genética , Camundongos , Camundongos Transgênicos , Telomerase/genética , Vacinas de DNA , Células Vero
12.
Viruses ; 11(1)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30650657

RESUMO

Flaviviruses, such as dengue (DENV), West Nile (WNV), yellow fever (YFV) and Zika (ZIKV) viruses, are mosquito-borne pathogens that present a major risk to global public health. To identify host factors that promote flavivirus replication, we performed a genome-wide gain-of-function cDNA screen for human genes that enhance the replication of flavivirus reporter particles in human cells. The screen recovered seventeen potential host proteins that promote viral replication, including the previously known dolichyl-diphosphooligosaccharide--protein glycosyltransferase non-catalytic subunit (DDOST). Using silencing approaches, we validated the role of four candidates in YFV and WNV replication: ribosomal protein L19 (RPL19), ribosomal protein S3 (RPS3), DDOST and importin 9 (IPO9). Applying a panel of virological, biochemical and microscopic methods, we validated further the role of RPL19 and DDOST as host factors required for optimal replication of YFV, WNV and ZIKV. The genome-wide gain-of-function screen is thus a valid approach to advance our understanding of flavivirus replication.


Assuntos
Flavivirus/genética , Interações Hospedeiro-Patógeno/genética , Replicação Viral , Animais , Linhagem Celular , Culicidae/virologia , Vírus da Dengue/genética , Flavivirus/fisiologia , Biblioteca Gênica , Hexosiltransferases/genética , Humanos , Carioferinas/genética , Proteínas de Membrana/genética , Proteínas Ribossômicas/genética , Vírus do Nilo Ocidental/genética , Zika virus/genética
13.
Expert Rev Vaccines ; 18(4): 393-403, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30601074

RESUMO

INTRODUCTION: The large global burden of viral infections and especially the rapidly spreading vector-borne diseases and other emerging viral diseases show the need for new approaches in vaccine development. Several new vaccine technology platforms have been developed and are under evaluation. Areas covered: This article discusses the measles vector platform technology derived from the safe and highly efficacious measles virus vaccine. The pipeline of measles-vectored vaccine candidates against viral diseases is reviewed. Particular focus is given to the Chikungunya vaccine candidate as the first measles-vectored vaccine that demonstrated safety, immunogenicity, and functionality of the technology in humans even in the presence of pre-existing anti-measles immunity and thus achieved proof of concept for the technology. Expert commentary: Demonstrating no impact of pre-existing anti-measles immunity in humans on the response to the transgene was fundamental for the technology and indicates that the technology is suitable for large-scale immunization in measles pre-immune populations. The proof of concept in humans combined with a large preclinical track record of safety, immunogenicity, and efficacy for a variety of pathogens suggest the measles vector platform as promising plug-and-play vaccine platform technology for rapid development of effective preventive vaccines against viral and other infectious diseases.

14.
Viruses ; 12(1)2019 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-31906112

RESUMO

Lassa virus (LASV) and Mopeia virus (MOPV) are two closely related, rodent-born mammarenaviruses. LASV is the causative agent of Lassa fever, a deadly hemorrhagic fever endemic in West Africa, whereas MOPV is non-pathogenic in humans. The Z matrix protein of arenaviruses is essential to virus assembly and budding by recruiting host factors, a mechanism that remains partially defined. To better characterize the interactions involved, a yeast two-hybrid screen was conducted using the Z proteins from LASV and MOPV as a bait. The cellular proteins ITCH and WWP1, two members of the Nedd4 family of HECT E3 ubiquitin ligases, were found to bind the Z proteins of LASV, MOPV and other arenaviruses. The PPxY late-domain motif of the Z proteins is required for the interaction with ITCH, although the E3 ubiquitin-ligase activity of ITCH is not involved in Z ubiquitination. The silencing of ITCH was shown to affect the replication of the old-world mammarenaviruses LASV, MOPV, Lymphocytic choriomeningitis virus (LCMV) and to a lesser extent Lujo virus (LUJV). More precisely, ITCH was involved in the egress of virus-like particles and the release of infectious progeny viruses. Thus, ITCH constitutes a novel interactor of LASV and MOPV Z proteins that is involved in virus assembly and release.

15.
Blood Adv ; 2(23): 3492-3505, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30530776

RESUMO

In this study, we assessed the sensitivity of myeloma cells to the oncolytic measles virus (MV) in relation to p53 using 37 cell lines and 23 primary samples. We showed that infection and cell death were correlated with CD46 expression, which was associated with TP53 status; TP53 abn cell lines highly expressed CD46 and were preferentially infected by MV when compared with the TP53 wt cell lines (P = .046 and P = .045, respectively). Infection of myeloma cells was fully dependent on CD46 expression in both cell lines and primary cells. In the TP53 wt cell lines, but not the TP53 abn cell lines, activation of the p53 pathway with nutlin3a inhibited both CD46 expression and MV infection, while TP53 silencing reciprocally increased CD46 expression and MV infection. We showed using a p53 chromatin immunoprecipitation assay and microRNA assessment that CD46 gene expression was directly and indirectly regulated by p53. Primary myeloma cells overexpressed CD46 as compared with normal cells and were highly infected and killed by MV. CD46 expression and MV infection were inhibited by nutlin3a in primary p53-competent myeloma cells, but not in p53-deficient myeloma cells, and the latter were highly sensitive to MV infection. In summary, myeloma cells were highly sensitive to MV and infection inhibition by the p53 pathway was abrogated in p53-deficient myeloma cells. These results argue for an MV-based clinical trial for patients with p53 deficiency.


Assuntos
Vírus do Sarampo/fisiologia , Proteína Cofatora de Membrana/metabolismo , Mieloma Múltiplo/patologia , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Humanos , Proteína Cofatora de Membrana/antagonistas & inibidores , Proteína Cofatora de Membrana/genética , MicroRNAs/metabolismo , Mieloma Múltiplo/metabolismo , Ligação Proteica , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/química , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética
17.
RNA ; 24(10): 1285-1296, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30012569

RESUMO

Defective interfering (DI) genomes, or defective viral genomes (DVGs), are truncated viral genomes generated during replication of most viruses, including live viral vaccines. Among these, "panhandle" or copy-back (cb) and "hairpin" or snap-back (sb) DI genomes are generated during RNA virus replication. 5' cb/sb DI genomes are highly relevant for viral pathogenesis since they harbor immunostimulatory properties that increase virus recognition by the innate immune system of the host. We have developed DI-tector, a user-friendly and freely available program that identifies and characterizes cb/sb genomes from next-generation sequencing (NGS) data. DI-tector confirmed the presence of 5' cb genomes in cells infected with measles virus (MV). DI-tector also identified a novel 5' cb genome, as well as a variety of 3' cb/sb genomes whose existence had not previously been detected by conventional approaches in MV-infected cells. The presence of these novel cb/sb genomes was confirmed by RT-qPCR and RT-PCR, validating the ability of DI-tector to reveal the landscape of DI genome population in infected cell samples. Performance assessment using different experimental and simulated data sets revealed the robust specificity and sensitivity of DI-tector. We propose DI-tector as a universal tool for the unbiased detection of DI viral genomes, including 5' cb/sb DI genomes, in NGS data.


Assuntos
Vírus Defeituosos/genética , Genoma Viral , Genômica , Software , Linhagem Celular , Biologia Computacional/métodos , Genes de RNAr , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , RNA Viral , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Replicação Viral
18.
Cell Rep ; 24(2): 320-328, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29996094

RESUMO

The flavivirus genus comprises major human pathogens, such as Dengue (DENV) and Zika (ZIKV) viruses. RIG-I and MDA5 are key cytoplasmic pathogen recognition receptors that are implicated in detecting viral RNAs. Here, we show that RNAs that co-purified with RIG-I during DENV infection are immuno-stimulatory, whereas RNAs bound to MDA5 are not. An affinity purification method combined with next-generation sequencing (NGS) revealed that the 5' region of the DENV genome is recognized by RIG-I. No DENV RNA was bound to MDA5. In vitro production of fragments of the DENV genome confirmed the NGS data and revealed that the 5' end of the genome, when bearing 5'-triphosphates, is the RIG-I ligand. The 5' region of the ZIKV genome is also a RIG-I agonist. We propose that RIG-I binds to the highly structured and conserved 5' region of flavivirus nascent transcripts before capping and that this mechanism leads to interferon secretion by infected cells.


Assuntos
Proteína DEAD-box 58/metabolismo , Vírus da Dengue/genética , Genoma Viral , Zika virus/genética , Células Dendríticas/imunologia , Células Dendríticas/virologia , Dengue/virologia , Células HEK293 , Humanos , Replicação Viral/fisiologia
19.
Sci Rep ; 8(1): 10889, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30022130

RESUMO

Plasmacytoid dendritic cells (pDCs) are specialized in the production of interferons (IFNs) in response to viral infections. The Flaviviridae family comprises enveloped RNA viruses such as Hepatitis C virus (HCV) and Dengue virus (DENV). Cell-free flaviviridae virions poorly stimulate pDCs to produce IFN. By contrast, cells infected with HCV and DENV potently stimulate pDCs via short-range delivery of viral RNAs, which are either packaged within immature virions or secreted exosomes. We report that cells infected with Yellow fever virus (YFV), the prototypical flavivirus, stimulated pDCs to produce IFNs in a TLR7- and cell contact- dependent manner. Such stimulation was unaffected by the presence of YFV neutralizing antibodies. As reported for DENV, cells producing immature YFV particles were more potent at stimulating pDCs than cells releasing mature virions. Additionally, cells replicating a release-deficient YFV mutant or a YFV subgenomic RNA lacking structural protein-coding sequences participated in pDC stimulation. Thus, viral RNAs produced by YFV-infected cells reach pDCs via at least two mechanisms: within immature particles and as capsid-free RNAs. Our work highlights the ability of pDCs to respond to a variety of viral RNA-laden carriers generated from infected cells.


Assuntos
Capsídeo , Células Dendríticas/imunologia , Interferons/metabolismo , RNA Viral/metabolismo , Vírion/imunologia , Febre Amarela/imunologia , Vírus da Febre Amarela/imunologia , Adulto , Idoso , Células Cultivadas , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/genética , Vírion/metabolismo , Febre Amarela/metabolismo , Febre Amarela/virologia , Adulto Jovem
20.
Oncoimmunology ; 7(3): e1407897, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29399408

RESUMO

Oncolytic immunotherapy using oncolytic viruses (OV) has been shown to stimulate the antitumor immune response by inducing the release of tumor-associated antigens (TAA) and danger signals from the dying infected tumor cells. In this study, we sought to determine if the lysis of tumor cells induced by different OV: measles virus, vaccinia virus, vesicular stomatitis virus, herpes simplex type I virus, adenovirus or enterovirus, has consequences on the capacity of tumor cells to present TAA, such as NY-ESO-1. We show that the co-culture of NY-ESO-1neg/HLA-DP4pos melanoma cells with NY-ESO-1pos/HLA-DP4neg melanoma cells infected and killed by different OV induces an intercellular transfer of NY-ESO-1 that allows the recognition of NY-ESO-1neg/HLA-DP4pos tumor cells by an HLA-DP4/NY-ESO-1(157-170)-specific CD4+ cytotoxic T cell clone, NY67. We then confirmed this result in a second model with an HLA-DP4+ melanoma cell line that expresses a low amount of NY-ESO-1. Recognition of this cell line by the NY67 clone is largely increased in the presence of OV productive infection. Altogether, our results show for the first time another mechanism of stimulation of the anti-tumor immune response by OV, via the loading of tumor cells with TAA that sensitizes them for direct recognition by specific effector CD4+ T cells, supporting the use of OV for cancer immunotherapy.

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