Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.376
Filtrar
1.
J Exp Med ; 218(4)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33544838

RESUMO

Yellow fever virus (YFV) live attenuated vaccine can, in rare cases, cause life-threatening disease, typically in patients with no previous history of severe viral illness. Autosomal recessive (AR) complete IFNAR1 deficiency was reported in one 12-yr-old patient. Here, we studied seven other previously healthy patients aged 13 to 80 yr with unexplained life-threatening YFV vaccine-associated disease. One 13-yr-old patient had AR complete IFNAR2 deficiency. Three other patients vaccinated at the ages of 47, 57, and 64 yr had high titers of circulating auto-Abs against at least 14 of the 17 individual type I IFNs. These antibodies were recently shown to underlie at least 10% of cases of life-threatening COVID-19 pneumonia. The auto-Abs were neutralizing in vitro, blocking the protective effect of IFN-α2 against YFV vaccine strains. AR IFNAR1 or IFNAR2 deficiency and neutralizing auto-Abs against type I IFNs thus accounted for more than half the cases of life-threatening YFV vaccine-associated disease studied here. Previously healthy subjects could be tested for both predispositions before anti-YFV vaccination.


Assuntos
Anticorpos Neutralizantes/imunologia , Autoanticorpos/imunologia , Doenças Autoimunes , COVID-19 , Doenças Genéticas Inatas , Interferon-alfa , Receptor de Interferon alfa e beta , SARS-CoV-2 , Vacina contra Febre Amarela , Vírus da Febre Amarela , Adolescente , Adulto , Idoso , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , COVID-19/genética , COVID-19/imunologia , Feminino , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/imunologia , Células HEK293 , Humanos , Interferon-alfa/genética , Interferon-alfa/imunologia , Masculino , Pessoa de Meia-Idade , Receptor de Interferon alfa e beta/deficiência , Receptor de Interferon alfa e beta/imunologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacina contra Febre Amarela/efeitos adversos , Vacina contra Febre Amarela/genética , Vacina contra Febre Amarela/imunologia , Vírus da Febre Amarela/genética , Vírus da Febre Amarela/imunologia
2.
PLoS One ; 16(1): e0244439, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33444326

RESUMO

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease representing a serious unmet medical need. The disease is associated with the loss of self-tolerance and exaggerated B cell activation, resulting in autoantibody production and the formation of immune complexes that accumulate in the kidney, causing glomerulonephritis. TLR7, an important mediator of the innate immune response, drives the expression of type-1 interferon (IFN), which leads to expression of type-1 IFN induced genes and aggravates lupus pathology. Because the lysosomal peptide symporter slc15a4 is critically required for type-1 interferon production by pDC, and for certain B cell functions in response to TLR7 and TLR9 signals, we considered it as a potential target for pharmacological intervention in SLE. We deleted the slc15a4 gene in C57BL/6, NZB, and NZW mice and found that pristane-challenged slc15a4-/- mice in the C57BL/6 background and lupus prone slc15a4-/- NZB/W F1 mice were both completely protected from lupus like disease. In the NZB/W F1 model, protection persisted even when disease development was accelerated with an adenovirus encoding IFNα, emphasizing a broad role of slc15a4 in disease initiation. Our results establish a non-redundant function of slc15a4 in regulating both innate and adaptive components of the immune response in SLE pathobiology and suggest that it may be an attractive drug target.


Assuntos
Lúpus Eritematoso Sistêmico/patologia , Proteínas de Membrana Transportadoras/metabolismo , Animais , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Imidazóis/farmacologia , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferon-alfa/farmacologia , Lúpus Eritematoso Sistêmico/metabolismo , Lúpus Eritematoso Sistêmico/mortalidade , Proteínas de Membrana Transportadoras/deficiência , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NZB , Camundongos Knockout , Taxa de Sobrevida , Terpenos/farmacologia , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo
3.
Eur J Immunol ; 51(4): 989-994, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33314090

RESUMO

Low concentrations of type-I interferon (IFN) in blood seem to be associated with more severe forms of Coronavirus disease 2019 (COVID-19). However, following the type-I interferon response (IR) in early stage disease is a major challenge. We evaluated detection of a molecular interferon signature on a FilmArray® system, which includes PCR assays for four interferon stimulated genes. We analyzed three types of patient populations: (i) children admitted to a pediatric emergency unit for fever and suspected infection, (ii) ICU-admitted patients with severe COVID-19, and (iii) healthcare workers with mild COVID-19. The results were compared to the reference tools, that is, molecular signature assessed with Nanostring® and IFN-α2 quantification by SIMOA® (Single MOlecule Array). A strong correlation was observed between the IR measured by the FilmArray®, Nanostring®, and SIMOA® platforms (r-Spearman 0.996 and 0.838, respectively). The FilmArray® panel could be used in the COVID-19 pandemic to evaluate the IR in 45-min with 2 min hand-on-time at hospitalization and to monitor the IR in future clinical trials.


Assuntos
COVID-19/sangue , Interferon-alfa/sangue , Reação em Cadeia da Polimerase/métodos , SARS-CoV-2/imunologia , Adulto , Idoso , COVID-19/imunologia , Criança , Feminino , Pessoal de Saúde , Humanos , Interferon Tipo I/sangue , Interferon Tipo I/genética , Interferon-alfa/genética , Masculino
4.
Signal Transduct Target Ther ; 5(1): 221, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024073
5.
Nat Rev Immunol ; 20(10): 585-586, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32788708
6.
J Exp Med ; 217(12)2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-32820330

RESUMO

Type I interferons (IFN-I) are a major antiviral defense and are critical for the activation of the adaptive immune system. However, early viral clearance by IFN-I could limit antigen availability, which could in turn impinge upon the priming of the adaptive immune system. In this study, we hypothesized that transient IFN-I blockade could increase antigen presentation after acute viral infection. To test this hypothesis, we infected mice with viruses coadministered with a single dose of IFN-I receptor-blocking antibody to induce a short-term blockade of the IFN-I pathway. This resulted in a transient "spike" in antigen levels, followed by rapid antigen clearance. Interestingly, short-term IFN-I blockade after coronavirus, flavivirus, rhabdovirus, or arenavirus infection induced a long-lasting enhancement of immunological memory that conferred improved protection upon subsequent reinfections. Short-term IFN-I blockade also improved the efficacy of viral vaccines. These findings demonstrate a novel mechanism by which IFN-I regulate immunological memory and provide insights for rational vaccine design.


Assuntos
Imunogenicidade da Vacina/imunologia , Interferon Tipo I/antagonistas & inibidores , Interferon-alfa/imunologia , Receptor de Interferon alfa e beta/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Animais , Anticorpos Bloqueadores/imunologia , Anticorpos Bloqueadores/farmacologia , Anticorpos Antivirais/imunologia , Apresentação do Antígeno/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/imunologia , Modelos Animais de Doenças , Expressão Gênica/imunologia , Células HEK293 , Humanos , Memória Imunológica , Interferon-alfa/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Interferon alfa e beta/genética , Transfecção , Infecção por Zika virus/virologia
7.
J Virol ; 94(17)2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32581092

RESUMO

Covalently closed circular DNA (cccDNA) of hepadnaviruses exists as an episomal minichromosome in the nucleus of an infected hepatocyte and serves as the template for the transcription of viral mRNAs. It had been demonstrated by others and us that interferon alpha (IFN-α) treatment of hepatocytes induced a prolonged suppression of human and duck hepatitis B virus cccDNA transcription, which is associated with the reduction of cccDNA-associated histone modifications specifying active transcription (H3K9ac or H3K27ac), but not the histone modifications marking constitutive (H3K9me3) or facultative (H3K27me3) heterochromatin formation. In our efforts to identify IFN-induced cellular proteins that mediate the suppression of cccDNA transcription by the cytokine, we found that downregulating the expression of signal transducer and activator of transcription 1 (STAT1), structural maintenance of chromosomes flexible hinge domain containing 1 (SMCHD1), or promyelocytic leukemia (PML) protein increased basal level of cccDNA transcription activity and partially attenuated IFN-α suppression of cccDNA transcription. In contrast, ectopic expression of STAT1, SMCHD1, or PML significantly reduced cccDNA transcription activity. SMCHD1 is a noncanonical SMC family protein and implicated in epigenetic silencing of gene expression. PML is a component of nuclear domain 10 (ND10) and is involved in suppressing the replication of many DNA viruses. Mechanistic analyses demonstrated that STAT1, SMCHD1, and PML were recruited to cccDNA minichromosomes and phenocopied the IFN-α-induced posttranslational modifications of cccDNA-associated histones. We thus conclude that STAT1, SMCHD1, and PML may partly mediate the suppressive effect of IFN-α on hepadnaviral cccDNA transcription.IMPORTANCE Pegylated IFN-α is the only therapeutic regimen that can induce a functional cure of chronic hepatitis B in a small, but significant, fraction of treated patients. Understanding the mechanisms underlying the antiviral functions of IFN-α in hepadnaviral infection may reveal molecular targets for development of novel antiviral agents to improve the therapeutic efficacy of IFN-α. By a loss-of-function genetic screening of individual IFN-stimulated genes (ISGs) on hepadnaviral mRNAs transcribed from cccDNA, we found that downregulating the expression of STAT1, SMCHD1, or PML significantly increased the level of viral RNAs without altering the level of cccDNA. Mechanistic analyses indicated that those cellular proteins are recruited to cccDNA minichromosomes and induce the posttranslational modifications of cccDNA-associated histones similar to those induced by IFN-α treatment. We have thus identified three IFN-α-induced cellular proteins that suppress cccDNA transcription and may partly mediate IFN-α silencing of hepadnaviral cccDNA transcription.


Assuntos
DNA Circular/metabolismo , Hepadnaviridae/efeitos dos fármacos , Hepadnaviridae/genética , Interferon-alfa/metabolismo , Interferon-alfa/farmacologia , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Linhagem Celular , Galinhas , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/metabolismo , DNA Viral/genética , Epigênese Genética , Infecções por Hepadnaviridae/virologia , Vírus da Hepatite B do Pato/efeitos dos fármacos , Vírus da Hepatite B , Hepatite B Crônica/virologia , Hepatócitos/virologia , Código das Histonas , Histonas/metabolismo , Humanos , Interferon-alfa/genética , Proteína da Leucemia Promielocítica/metabolismo , Processamento de Proteína Pós-Traducional , RNA Viral , Fator de Transcrição STAT1/metabolismo , Transcrição Genética , Replicação Viral
8.
Yakugaku Zasshi ; 140(5): 687-700, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32378673

RESUMO

Recent advances in high-throughput technologies have revealed that 75% of the human genome is transcribed to RNA, whereas only 3% of transcripts are translated into proteins. Consequently, many long non-coding RNAs (lncRNAs) have been identified, which has improved our understanding of the complexity of biological processes. LncRNAs comprise multiple classes of RNA transcripts that regulate the transcription, stability and translation of protein-coding genes in a genome. Natural antisense transcripts (NATs) form one such class, and the GENCODE v30 catalog contains 16193 lncRNA loci, of which 5611 are antisense loci. This review outlines our emerging understanding of lncRNAs, with a particular focus on how lncRNAs regulate gene expression using interferon-α1 (IFN-α1) mRNA and its antisense partner IFN-α1 antisense (as)RNA as an example. We have identified and characterized the asRNA that determines post-transcriptional IFN-α1 mRNA levels. IFN-α1 asRNA stabilizes IFN-α1 mRNA by cytoplasmic sense-antisense duplex formation, which may enhance the accessibility of an RNA stabilizer protein or decrease the affinity of an RNA decay factor for the RNA. IFN-α1 asRNA can also act as competing molecules in the competing endogenous (ce)RNA network with other members of the IFNA multigene family mRNAs/asRNAs, and other cellular mRNA transcripts. Furthermore, antisense oligoribonucleotides representing functional domains of IFN-α1 asRNA inhibit influenza virus proliferation in the respiratory tract of virus-infected animals. Thus, these findings support, at least in part, the rationale that dissecting the activity of NAT on gene expression regulation promises to reveal previously unanticipated biology, with potential to provide new therapeutic approaches to diseases.


Assuntos
Regulação da Expressão Gênica/genética , RNA Antissenso/fisiologia , RNA não Traduzido/fisiologia , Animais , Genoma Humano/genética , Humanos , Interferon-alfa/química , Interferon-alfa/genética , Família Multigênica , Oligorribonucleotídeos Antissenso/fisiologia , Orthomyxoviridae/fisiologia , Estabilidade de RNA , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Sistema Respiratório/virologia , Transcrição Genética/genética , Replicação Viral
9.
Immunity ; 52(4): 668-682.e7, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32294407

RESUMO

The primary mechanisms supporting immunoregulatory polarization of myeloid cells upon infiltration into tumors remain largely unexplored. Elucidation of these signals could enable better strategies to restore protective anti-tumor immunity. Here, we investigated the role of the intrinsic activation of the PKR-like endoplasmic reticulum (ER) kinase (PERK) in the immunoinhibitory actions of tumor-associated myeloid-derived suppressor cells (tumor-MDSCs). PERK signaling increased in tumor-MDSCs, and its deletion transformed MDSCs into myeloid cells that activated CD8+ T cell-mediated immunity against cancer. Tumor-MDSCs lacking PERK exhibited disrupted NRF2-driven antioxidant capacity and impaired mitochondrial respiratory homeostasis. Moreover, reduced NRF2 signaling in PERK-deficient MDSCs elicited cytosolic mitochondrial DNA elevation and, consequently, STING-dependent expression of anti-tumor type I interferon. Reactivation of NRF2 signaling, conditional deletion of STING, or blockade of type I interferon receptor I restored the immunoinhibitory potential of PERK-ablated MDSCs. Our findings demonstrate the pivotal role of PERK in tumor-MDSC functionality and unveil strategies to reprogram immunosuppressive myelopoiesis in tumors to boost cancer immunotherapy.


Assuntos
Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Epitelial do Ovário/imunologia , Regulação Neoplásica da Expressão Gênica , Melanoma Experimental/imunologia , Proteínas de Membrana/imunologia , Neoplasias Cutâneas/imunologia , eIF-2 Quinase/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/metabolismo , Carcinoma Pulmonar de Lewis/patologia , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Feminino , Humanos , Imunossupressão , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon beta/genética , Interferon beta/imunologia , Masculino , Melanoma Experimental/genética , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/patologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/imunologia , Receptores de Interferon/genética , Receptores de Interferon/imunologia , Transdução de Sinais , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Resposta a Proteínas não Dobradas/imunologia , eIF-2 Quinase/deficiência , eIF-2 Quinase/genética
10.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188736

RESUMO

Hepatitis B virus (HBV) chronically infects approximately 350 million people worldwide, and 600,000 deaths are caused by HBV-related hepatic failure, liver cirrhosis, and hepatocellular carcinoma annually. It is important to reveal the mechanism underlying the regulation of HBV replication. This study demonstrated that osteopetrosis-associated transmembrane protein 1 (Ostm1) plays an inhibitory role in HBV replication. Ostm1 represses the levels of HBeAg and HBsAg proteins, HBV 3.5-kb and 2.4/2.1-kb RNAs, and core-associated DNA in HepG2, Huh7, and NTCP-HepG2 cells. Notably, Ostm1 has no direct effect on the activity of HBV promoters or the transcription of HBV RNAs; instead, Ostm1 binds to HBV RNA to facilitate RNA decay. Detailed studies further demonstrated that Ostm1 binds to and recruits the RNA exosome complex to promote the degradation of HBV RNAs, and knockdown of the RNA exosome component exonuclease 3 (Exosc3) leads to the elimination of Ostm1-mediated repression of HBV replication. Mutant analyses revealed that the N-terminal domain, the transmembrane domain, and the C-terminal domain are responsible for the repression of HBV replication, and the C-terminal domain is required for interaction with the RNA exosome complex. Moreover, Ostm1 production is not regulated by interferon-α (IFN-α) or IFN-γ, and the expression of IFN signaling components is not affected by Ostm1, suggesting that Ostm1 anti-HBV activity is independent of the IFN signaling pathway. In conclusion, this study revealed a distinct mechanism underlying the repression of HBV replication, in which Ostm1 binds to HBV RNA and recruits RNA exosomes to degrade viral RNA, thereby restricting HBV replication.IMPORTANCE Hepatitis B virus (HBV) is a human pathogen infecting the liver to cause a variety of diseases ranging from acute hepatitis to advanced liver diseases, fulminate hepatitis, liver cirrhosis, and hepatocellular carcinoma, thereby causing a major health problem worldwide. In this study, we demonstrated that Ostm1 plays an inhibitory role in HBV protein production, RNA expression, and DNA replication. However, Ostm1 has no effect on the activities of the four HBV promoters; instead, it binds to HBV RNA and recruits RNA exosomes to promote HBV RNA degradation. We further demonstrated that the anti-HBV activity of Ostm1 is independent of the interferon signaling pathway. In conclusion, this study reveals a distinct mechanism underlying the repression of HBV replication and suggests that Ostm1 is a potential therapeutic agent for HBV infection.


Assuntos
Exossomos/metabolismo , Vírus da Hepatite B/fisiologia , Proteínas de Membrana/metabolismo , RNA Viral/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Replicação Viral , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Exossomos/genética , Exossomos/virologia , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Células Hep G2 , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/metabolismo , Antígenos E da Hepatite B/genética , Antígenos E da Hepatite B/metabolismo , Humanos , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Proteínas de Membrana/genética , Domínios Proteicos , RNA Viral/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ubiquitina-Proteína Ligases/genética
11.
Biochem Biophys Res Commun ; 525(2): 477-482, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32111355

RESUMO

Plasmacytoid dendritic cells (pDCs) are characterized by an exclusive expression of nucleic acid sensing Toll-like receptor 7 (TLR7) and TLR9, and production of high amounts of type I interferon (IFN) in response to TLR7/9 signaling. This function is crucial for both antiviral immunity and the pathogenesis of autoimmune diseases. An Ets family transcription factor, i.e., Spi-B (which is highly expressed in pDCs) is required for TLR7/9 signal-induced type I IFN production and can transactivate IFN-α promoter in synergy with IFN regulatory factor-7 (IRF-7). Herein, we analyzed how Spi-B contributes to the transactivation of the Ifna4 promoter. We performed deletion and/or mutational analyses of the Ifna4 promoter and an electrophoretic mobility shift assay (EMSA) and observed an Spi-B binding site in close proximity to the IRF-7 binding site. The EMSA results also showed that the binding of Spi-B to the double-stranded DNA probe potentiated the recruitment of IRF-7 to its binding site. We also observed that the association of Spi-B with transcriptional coactivator p300 was required for the Spi-B-induced synergistic enhancement of the Ifna4 promoter activity by Spi-B. These results clarify the molecular mechanism of action of Spi-B in the transcriptional activation of the Ifna4 promoter.


Assuntos
Interferon-alfa/genética , Proteínas Proto-Oncogênicas c-ets/metabolismo , Ativação Transcricional , Animais , Proteína p300 Associada a E1A/metabolismo , Células HEK293 , Humanos , Camundongos , Mutação , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-ets/genética
12.
Gene ; 741: 144539, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32160960

RESUMO

microRNAs (miRNAs) are involved in the physiological and pathophysiological processes of diabetes and its microvascular and macrovascular complications. Hence, the aim of the study was to investigate whether miR-499-3p played an important role in diabetic retinopathy. Diabetic retinopathy was developed in rats by intraperitoneal injection of streptozocin (STZ), followed by collection of retinal tissues and preparation of retinal cells. Immunohistochemical staining was used to detect expression of interferon alpha 2 (IFNA2). RT-qPCR was used to determine the expression of miR-499-3p. Bioinformatics website and dual luciferase reporter gene assay were used to validate the targeting relationship between miR-499-3p and IFNA2. Gain- and loss-of-function assays were performed to explore the functional roles of aberrantly expressed miR-499-3p and IFNA2 in retinal cell proliferation by MTT, and apoptosis by flow cytometry. In retinal tissues and cells of diabetic rats, IFNA2 expression was reduced, and miR-499-3p expression increased to activate the toll-like receptor 4 (TLR4) signaling pathway. IFNA2 was a target gene of miR-499-3p and negatively regulated by miR-499-3p. Further, downregulated miR-499-3p promoted retinal cell proliferation while suppressing apoptosis to alleviate diabetic retinopathy. All in all, miR-499-3p promoted retinopathy by enhancing activation of the TLR4 signaling pathway, which provides a new therapeutic target for diabetic retinopathy.


Assuntos
Retinopatia Diabética/genética , Interferon-alfa/genética , MicroRNAs/genética , Receptor 4 Toll-Like/genética , Animais , Apoptose/genética , Proliferação de Células/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Retinopatia Diabética/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Ratos , Retina/metabolismo , Retina/patologia , Transdução de Sinais/genética
13.
BMC Biotechnol ; 20(1): 16, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32169063

RESUMO

BACKGROUND: The type I human interferon (IFN) family consists of a group of cytokines with a multiplicity of biological activities, including antiviral, antitumor, and immunomodulatory effects. However, because the half-life of IFN is short, its clinical application is limited. Increasing the yield and biological activity of IFN while extending its half-life is currently the focus of IFN research. RESULTS: Two novel long-acting recombinant human IFN-α2b (rhIFN-α2b) proteins were designed in which the carboxyl-terminal peptide (CTP) of the human chorionic gonadotropin ß su bunit and N-linked glycosylation sequences were linked to rhIFN-α2b. They were designated IFN-1CTPON (fused at the C-terminus of rhIFN-α2b) and IFN-2CTPON (fused at both the C-terminus and N-terminus of rhIFN-α2b). Monoclonal CHO cell strains stably and efficiently expressing the IFNs were successfully selected with methotrexate (MTX), and the highest expression levels were 1468 mg/l and 1196 mg/l for IFN-1CTPON and IFN-2CTPON, respectively. The proteins were purified with affinity chromatography and molecular sieve chromatography. IFN-1CTPON and IFN-2CTPON showed antiviral and antiproliferative activities in vitro. Notably, the half-life of IFN-1CTPON and IFN-2CTPON in vivo were three-fold and two-fold longer than that of commercially available rhIFN-α2b. CONCLUSIONS: CHO cell strains stably expressing long-acting rhIFN-α2b were screened. The purified IFN-CTPON protein has biological activity and an extended half-life, and therefore potential applications.


Assuntos
Antineoplásicos/farmacologia , Antivirais/farmacologia , Gonadotropina Coriônica Humana Subunidade beta/genética , Interferon-alfa/genética , Proteínas Recombinantes de Fusão/farmacologia , Animais , Células CHO , Proliferação de Células/efeitos dos fármacos , Gonadotropina Coriônica Humana Subunidade beta/química , Cromatografia de Afinidade , Cricetulus , Preparações de Ação Retardada , Glicosilação , Meia-Vida , Células HeLa , Vírus da Hepatite B/efeitos dos fármacos , Humanos , Interferon-alfa/metabolismo , Interferon-alfa/farmacologia , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/metabolismo
14.
Int J Mol Sci ; 21(4)2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32098104

RESUMO

Nervous necrosis virus (NNV) results in high mortality rates of infected marine fish worldwide. Interferons (IFNs) are cytokines in vertebrates that suppress viral replication and regulate immune responses. Heterologous overexpression of fish IFN in bacteria could be problematic because of protein solubility and loss of function due to protein misfolding. In this study, a protein model of the IFN-α of Epinephelus septemfasciatus was built based on comparative modeling. In addition, PelB and SacB signal peptides were fused to the N-terminus of E. septemfasciatus IFN-α for overexpression of soluble, secreted IFN in Escherichia coli (E-IFN) and Bacillus subtilis (B-IFN). Cytotoxicity tests indicated that neither recombinant grouper IFN-α were cytotoxic to a grouper head kidney cell line (GK). The GK cells stimulated with E-IFN and B-IFN exhibited elevated expression of antiviral Mx genes when compared with the control group. The NNV challenge experiments demonstrated that GK cells pretreated or co-treated with E-IFN and B-IFN individually had three times the cell survival rates of untreated cells, indicating the cytoprotective ability of our recombinant IFNs. These data provide a protocol for the production of soluble, secreted, and functional grouper IFN of high purity, which may be applied to aquaculture fisheries for antiviral infection.


Assuntos
Bacillus subtilis , Escherichia coli , Proteínas de Peixes , Interferon-alfa , Perciformes/genética , Animais , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Linhagem Celular , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Peixes/biossíntese , Proteínas de Peixes/genética , Proteínas de Peixes/farmacologia , Interferon-alfa/biossíntese , Interferon-alfa/genética , Interferon-alfa/farmacologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
15.
Int J Mol Sci ; 21(3)2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32046242

RESUMO

Among environmental factors likely associated with Alzheimer's disease (AD), persistent virus infections, and age-related progressive decline of immune competence might play a pivotal role. However, AD antimicrobial brain immune responses are poorly investigated. The present study focused on genes involved in antimicrobial defenses, especially against virus infections, in the AD brain. In particular, mRNA levels of IRF7, MED23, IL28B, and IFN-α genes were analyzed in hippocampus and temporal cortex brain samples from AD and non-demented controls. All subjects were also genotyped for APOE ε, IRF7, MED23, and IL28B gene polymorphisms. Most AD patients showed decreased mRNA levels of all investigated genes in the hippocampus and temporal cortex. However, a small group of AD patients showed increased hippocampal mRNA expression of MED23, IL28B, and IFN-α. mRNA levels of MED23, IL28B, IFN-α from the hippocampus and those of MED23 from the temporal cortex were further decreased in APOE ε4 allele AD carriers. Moreover, rs6598008 polymorphism of IRF7 was significantly associated with decreased hippocampal expression of IRF7, MED23, IL28B, and IFN-α. These findings suggest that AD brains show impaired innate antimicrobial gene expression profiles, and individual genetic makeup, such as positivity for the APOE ε4 and IRF7 A alleles, might affect brain immune efficiency.


Assuntos
Doença de Alzheimer/imunologia , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Hipocampo/metabolismo , Imunidade Inata/fisiologia , Idoso , Idoso de 80 Anos ou mais , Alelos , Doença de Alzheimer/genética , Feminino , Humanos , Imunidade Inata/genética , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/metabolismo , Interferon-alfa/genética , Interferon-alfa/metabolismo , Interferons/genética , Interferons/metabolismo , Masculino , Complexo Mediador/genética , Complexo Mediador/metabolismo , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
16.
J Biomed Sci ; 27(1): 4, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31898495

RESUMO

Dengue virus (DENV) is the etiological agent of dengue fever. Severe dengue could be fatal and there is currently no effective antiviral agent or vaccine. The only licensed vaccine, Dengvaxia, has low efficacy against serotypes 1 and 2. Cellular miRNAs are post-transcriptional regulators that could play a role in direct regulation of viral genes. Host miRNA expressions could either promote or repress viral replications. Induction of some cellular miRNAs could help the virus to evade the host immune response by suppressing the IFN-α/ß signaling pathway while others could upregulate IFN-α/ß production and inhibit the viral infection. Understanding miRNA expressions and functions during dengue infections would provide insights into the development of miRNA-based therapeutics which could be strategized to act either as miRNA antagonists or miRNA mimics. The known mechanisms of how miRNAs impact DENV replication are diverse. They could suppress DENV multiplication by directly binding to the viral genome, resulting in translational repression. Other miRNA actions include modulation of host factors. In addition, miRNAs that could modulate immunopathogenesis are discussed. Major hurdles lie in the development of chemical modifications and delivery systems for in vivo delivery. Nevertheless, advancement in miRNA formulations and delivery systems hold great promise for the therapeutic potential of miRNA-based therapy, as supported by Miravirsen for treatment of Hepatitis C infection which has successfully completed phase II clinical trial.


Assuntos
Dengue/tratamento farmacológico , Interferon-alfa/genética , Interferon beta/genética , MicroRNAs/genética , Antivirais , Dengue/genética , Dengue/virologia , Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Humanos , Imunidade Inata/genética , Interferon-alfa/uso terapêutico , Interferon beta/uso terapêutico , MicroRNAs/uso terapêutico , Transdução de Sinais/genética , Replicação Viral/genética
17.
Microb Pathog ; 140: 103965, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31904449

RESUMO

Coxsackie B viruses (CV-B) are associated with several central nervous system (CNS) disorders. These viruses are predominantly transmitted by fecal-oral route but vertical transmission can also occur. This work attempted to study the immune response ensuing vertical transmission of CV-B to the brain, and its eventual implementation in the brain pathogenesis. To this end, pregnant Swiss albino mice were inoculated with CV-B4 E2 or with sterile medium for control animals. At different ages after birth, brains were collected and analyzed for virus infection, histopathological changes and immune response. Infectious particles were detected in offspring's brain which demonstrates vertical transmission of the virus. This infection is persistent since the long lasting detection of viral RNA in offspring's brain. Some pathological signs including meningitis, edema and accumulation of inflammatory cells within and surrounding the inflammatory areas were observed. Immunoflorescence staining unveiled the presence of T lymphocytes and microgliosis in the sites of lesion for a long period after birth. Multiplex cytokines measurement upon supernatants of in vitro mixed brain cells and extracted mononuclear cells from offspring's brain has demonstrated an elevated secretion of the pro-inflammatory cytokines TNFα, IL-6 and IFNα and the chemokines RANTES and MCP-1. Hence, vertical transmission of CV-B4 and its persistence within offspring's brain can lead to pathological features linked to increased and sustained immune response.


Assuntos
Encéfalo/patologia , Infecções por Coxsackievirus/imunologia , Infecções por Coxsackievirus/transmissão , Enterovirus Humano B/fisiologia , Complicações Infecciosas na Gravidez/imunologia , Animais , Encéfalo/imunologia , Encéfalo/virologia , Infecções por Coxsackievirus/patologia , Infecções por Coxsackievirus/virologia , Citocinas/genética , Citocinas/imunologia , Enterovirus Humano B/genética , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas , Interferon-alfa/genética , Interferon-alfa/imunologia , Masculino , Camundongos , Gravidez , Complicações Infecciosas na Gravidez/genética , Complicações Infecciosas na Gravidez/patologia , Complicações Infecciosas na Gravidez/virologia , Linfócitos T/imunologia
18.
Prep Biochem Biotechnol ; 50(3): 281-291, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31718419

RESUMO

The use of interferon α-2 in combination with thymosin α-1 shows higher anti-cancer effect in comparison when both are used individually because of their synergistic effects. In this study we produced an important human interferon α-2-thymosin α-1 (IFNα2-Tα1) fusion protein with probable pharmaceutical properties coupled to its high-level expression, characterization, and study of its biological activity. The IFNα2-Tα1 fusion gene was constructed by over-lap extension PCR and expressed in Escherichia coli expression system. The expression of IFNα2-Tα1 fusion protein was optimized to higher level and its maximum expression was obtained in modified terrific broth medium when lactose was used as inducer. The fusion protein was refolded into its native biologically active form with maximum yield of 83.14% followed by purification with ∼98% purity and 69% final yield. A band of purified IFNα2-Tα1 fusion protein equal to ∼23 kDa was observed on 12 % SDS-PAGE gel. The integrity of IFNα2-Tα1 fusion protein was confirmed by western blot analysis and secondary structure was assessed by CD spectroscopy. When IFNα2-Tα1 fusion protein was subjected to its biological activity analysis it was observed that it exhibits both IFNα2 & Tα1 activities as well as significantly higher anticancer activity as compared to IFNα-2 alone.


Assuntos
Interferon-alfa , Proteínas Recombinantes de Fusão , Timalfasina , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Interferon-alfa/química , Interferon-alfa/genética , Interferon-alfa/isolamento & purificação , Interferon-alfa/farmacologia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Timalfasina/química , Timalfasina/genética , Timalfasina/isolamento & purificação , Timalfasina/farmacologia
19.
Protein Expr Purif ; 166: 105509, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31604114

RESUMO

Consensus interferon (cIFN) is a wholly synthetic therapeutic protein which is used to treat hepatitis C/B and certain types of malignancies. It has short serum half-life, therefore, to maintain its therapeutic level in the human body it requires thrice-weekly administration. Various strategies like PEGylation and micro-encapsulation have been developed during the last few years to enhance the pharmacokinetics of small therapeutic peptides. This study executed the human albumin-fusion technology, a simple and flexible approach to extend the serum circulating half-life of cIFN, because human serum albumin (HSA) has long circulating half-life (19 days) and very minute immunological activities. We integrated the codon-optimized HSA-cIFN fusion gene into Pichia pastoris genome by homologous recombination. The selection of hyper-resistant P. pastoris clone against Zeocin™ achieved a high-level secretory expression (250 mg/L) of fusion protein. HSA-cIFN fusion protein was purified using one-step purification by affinity chromatography with 34% recovery. The SDS-PAGE and SEC-HPLC analysis confirmed the final purified product has molecular weight of 87 kDa with 98% purity. Western blot analysis using anti-IFN antibodies further verified the purified HSA-cIFN fusion protein. The specific biological activity was 2.1 × 106 IU/mg as assessed by cytopathic inhibition assay, and half-life of fusion protein was estimated by in vitro thermal and proteolytic stability studies. This work concludes that by using albumin fusion technology, codon optimization and one-step purification a high yield of 86 mg/L of biologically active protein with improved serum half-life was obtained.


Assuntos
Interferon-alfa/genética , Pichia/genética , Proteínas Recombinantes de Fusão/genética , Albumina Sérica Humana/genética , Sequência de Aminoácidos , Clonagem Molecular , Fermentação , Interferon-alfa/química , Peso Molecular , Peptídeos/química , Pichia/química , Conformação Proteica , Estabilidade Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Albumina Sérica Humana/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...