RESUMO
RNA helicases are involved in the innate immune response against pathogens, including bacteria and viruses; however, their mechanism in the human airway epithelial cells is still not fully understood. Here, we demonstrated that DEAH (Asp-Glu-Ala-His) box polypeptide 35 (DHX35), a member of the DExD/H (Asp-Glu-x-Asp/His)-box helicase family, boosts antiviral innate immunity in human airway epithelial cells. DHX35 knockdown attenuated the production of interferon-ß (IFN-ß), IL6, and CXCL10, whereas DHX35 overexpression increased their production. Upon stimulation, DHX35 was constitutively expressed, but it translocated from the nucleus into the cytosol, where it recognized cytosolic poly(I:C) and poly(dA:dT) via its HELICc domain. Mitochondrial antiviral signaling protein (MAVS) acted as an adaptor for DHX35 and interacted with the HELICc domain of DHX35 using amino acids 360-510. Interestingly, DHX35 interacted with retinoic acid-inducible gene 1 (RIG-I), enhanced the binding affinity of RIG-I with poly(I:C) and poly(dA:dT), and formed a signalsome with MAVS to activate interferon regulatory factor 3 (IRF3), NF-κB-p65, and MAPK signaling pathways. These results indicate that DHX35 not only acted as a cytosolic nucleic acid sensor but also synergized with RIG-I to enhance antiviral immunity in human airway epithelial cells. Our results demonstrate a novel molecular mechanism for DHX35 in RIG-I-mediated innate immunity and provide a novel candidate for drug and vaccine design to control viral infections in the human airway.
Assuntos
Proteína DEAD-box 58 , RNA Helicases DEAD-box , Imunidade Inata , Receptores Imunológicos , Humanos , Proteína DEAD-box 58/metabolismo , Proteína DEAD-box 58/imunologia , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/imunologia , Receptores Imunológicos/metabolismo , Poli I-C/imunologia , Poli I-C/farmacologia , RNA Helicases/metabolismo , RNA Helicases/imunologia , Transdução de Sinais/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Células HEK293RESUMO
A 44-year-old woman with autism spectrum disorder developed bulbar symptoms and generalized muscle weakness 7 months before referral. Six months before, she was administered glucocorticoid for liver involvement. During the course, while she presented alopecia, skin ulcers, and poikiloderma, hyperCKemia was observed only twice. Due to complications including cardiac involvement and hearing loss as well, we suspected mitochondrial disease and performed a muscle biopsy. The muscle pathology showed sarcoplasmic myxovirus resistance A (MxA) expression with scattered pattern. Since anti-melanoma differentiation-associated gene 5 (MDA5) antibody was detected, we diagnosed the patient with anti-MDA5 antibody-positive dermatomyositis (DM). We reinforced immunosuppressive therapy, and her clinical symptoms and liver involvement were improved. When we diagnose a case of anti-MDA5 antibody-positive DM who is difficult to make clinical diagnosis, it may be valuable to evaluate sarcoplasmic MxA expression on muscle pathology.
Assuntos
Autoanticorpos , Dermatomiosite , Helicase IFIH1 Induzida por Interferon , Proteínas de Resistência a Myxovirus , Humanos , Dermatomiosite/imunologia , Dermatomiosite/diagnóstico , Feminino , Helicase IFIH1 Induzida por Interferon/imunologia , Adulto , Autoanticorpos/sangue , Proteínas de Resistência a Myxovirus/genética , RNA Helicases DEAD-box/imunologia , RNA Helicases DEAD-box/genética , Retículo Sarcoplasmático , Músculo Esquelético/patologiaRESUMO
RLR helicases RIG-I and MDA5, which are known as pattern recognition receptors to sense cytoplasmic viral RNAs and trigger antiviral immune responses, are DExD/H-box helicases. In teleost, whether and how non-RLR helicases regulate RLR helicases to affect viral infection remains unclear. Here, we report that the non-RLR helicase DHX40 from grass carp (namely gcDHX40) is a negative regulator of grass carp reovirus (GCRV) infection and RLR-mediated type I IFN production. GcDHX40 was a cytoplasmic protein. Ectopic expression of gcDHX40 facilitated GCRV replication and suppressed type I IFN production induced by GCRV infection and by those genes involved the RLR antiviral signaling pathway. Mechanistically, gcDHX40 promoted the generation of viral inclusion bodies (VIBs) by interacting with the NS38 protein of GCRV. Additionally, gcDHX40 interacted with RLR helicase, and impaired the formation of RLR-MAVS functional complexes. Taken together, our results indicate that gcDHX40 is a novel important proviral host factor involving in promoting the generation of GCRV VIBs and inhibiting the production of RLR-mediated type I IFNs.
Assuntos
Carpas , RNA Helicases DEAD-box , Doenças dos Peixes , Proteínas de Peixes , Imunidade Inata , Infecções por Reoviridae , Reoviridae , Proteínas não Estruturais Virais , Animais , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Proteínas não Estruturais Virais/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/virologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Carpas/imunologia , Carpas/genética , Infecções por Reoviridae/veterinária , Infecções por Reoviridae/imunologia , Reoviridae/fisiologia , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , RNA Helicases DEAD-box/metabolismo , Imunidade Inata/genética , RNA Helicases/genética , RNA Helicases/metabolismo , RNA Helicases/imunologia , Regulação da Expressão Gênica/imunologiaRESUMO
DDX43 is one of the members of the DExD/H-box protein family, and emerging data suggest that it may play an important role in antiviral immunity across mammals. However, little is known about DDX43 in the fish immune response. In this study, we isolated the cDNA sequence of ddx43 in Nile tilapia (Oreochromis niloticus). The ddx43 gene was 2338 bp in length, contained an open reading frame (ORF) of 2064 bp and encoded a polypeptide of 687 amino acids. The predicted protein of OnDDX43 has three conserved domains, including the RNA binding domain KH, DEAD-like helicase superfamily DEXDc and C-terminal HELICc domain. In healthy Nile tilapia, the Onddx43 transcript was broadly expressed in all examined tissues, with the highest expression levels in the muscle and brain and the lowest in the liver. After challenge with Streptococcus agalactiae, lipopolysaccharides (LPS) and polyinosinic polycytidylic acid (Poly I:C), the expression level of Onddx43 mRNA was upregulated or downregulated in all of the tissues tested. Overexpression of OnDDX43 in 293 T cells showed that it has a positive regulatory effect on IFN-ß. The subcellular localization showed that OnDDX43 was expressed in the cytoplasm. We performed further pull-down assays and found that OnDDX43 interacted with both interferon-ß promoter stimulator1 (IPS-1) and TIR domain-containing adaptor inducing interferon-ß (TRIF).
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transporte Vesicular/imunologia , Ciclídeos/imunologia , RNA Helicases DEAD-box/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Interferon beta/imunologia , Transdução de Sinais/imunologia , Animais , Ciclídeos/microbiologiaRESUMO
Detection of microbial products by multiprotein complexes known as inflammasomes is pivotal to host defense against pathogens. Nucleotide-binding domain leucine-rich repeat (NLR) CARD domain containing 4 (NLRC4) forms an inflammasome in response to bacterial products; this requires their detection by NLR family apoptosis inhibitory proteins (NAIPs), with which NLRC4 physically associates. However, the mechanisms underlying sterile NLRC4 inflammasome activation, which is implicated in chronic noninfectious diseases, remain unknown. Here, we report that endogenous short interspersed nuclear element (SINE) RNAs, which promote atrophic macular degeneration (AMD) and systemic lupus erythematosus (SLE), induce NLRC4 inflammasome activation independent of NAIPs. We identify DDX17, a DExD/H box RNA helicase, as the sensor of SINE RNAs that licenses assembly of an inflammasome comprising NLRC4, NLR pyrin domaincontaining protein 3, and apoptosis-associated speck-like proteincontaining CARD and induces caspase-1 activation and cytokine release. Inhibiting DDX17-mediated NLRC4 inflammasome activation decreased interleukin-18 release in peripheral blood mononuclear cells of patients with SLE and prevented retinal degeneration in an animal model of AMD. Our findings uncover a previously unrecognized noncanonical NLRC4 inflammasome activated by endogenous retrotransposons and provide potential therapeutic targets for SINE RNAdriven diseases.
Assuntos
Proteínas Reguladoras de Apoptose/imunologia , Proteínas de Ligação ao Cálcio/imunologia , RNA Helicases DEAD-box/imunologia , Inflamassomos/imunologia , RNA/imunologia , Retroelementos/imunologia , Animais , Proteínas Reguladoras de Apoptose/deficiência , Proteínas de Ligação ao Cálcio/deficiência , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Chickens are the natural host of Newcastle disease virus (NDV) and avian influenza virus (AIV). The discovery that the RIG-I gene, the primary RNA virus pattern recognition receptor (PRR) in mammals, is naturally absent in chickens has directed attention to studies of chicken RNA PRRs and their functions in antiviral immune responses. Here, we identified Asp-Glu-Ala-Asp (DEAD)-box helicase 1 (DDX1) as an essential RNA virus PRR in chickens and investigated its functions in anti-RNA viral infections. The chDDX1 gene was cloned, and cross-species sequence alignment and phylogenetic tree analyses revealed high conservation of DDX1 among vertebrates. A quantitative RT-PCR showed that chDDX1 mRNA are widely expressed in different tissues in healthy chickens. In addition, chDDX1 was significantly upregulated after infection with AIV, NDV, or GFP-expressing vesicular stomatitis virus (VSV-GFP). Overexpression of chDDX1 in DF-1 cells induced the expression of IFN-ß, IFN-stimulated genes (ISGs), and proinflammatory cytokines; it also inhibited NDV and VSV replications. The knockdown of chDDX1 increased the viral yield of NDV and VSV and decreased the production of IFN-ß, which was induced by RNA analog polyinosinic-polycytidylic acid (poly[I:C]), by AIV, and by NDV. We used a chicken IRF7 (chIRF7) knockout DF-1 cell line in a series of experiments to demonstrate that chDDX1 activates IFN signaling via the chIRF7 pathway. Finally, an in-vitro pulldown assay showed a strong and direct interaction between poly(I:C) and the chDDX1 protein, indicating that chDDX1 may act as an RNA PRR during IFN activation. In brief, our results suggest that chDDX1 is an important mediator of IFN-ß and is involved in RNA- and RNA virus-mediated chDDX1-IRF7-IFN-ß signaling pathways.
Assuntos
Proteínas Aviárias/imunologia , Galinhas/imunologia , RNA Helicases DEAD-box/imunologia , Imunidade Inata/imunologia , Interferon gama/imunologia , Animais , Infecções por Vírus de RNA/imunologia , Receptores de Reconhecimento de Padrão/imunologia , Transdução de Sinais/imunologiaRESUMO
The cytoplasmic retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) initiate interferon (IFN) production and antiviral gene expression in response to RNA virus infection. Consequently, RLR signalling is tightly regulated by both host and viral factors. Tripartite motif protein 25 (TRIM25) is an E3 ligase that ubiquitinates multiple substrates within the RLR signalling cascade, playing both ubiquitination-dependent and -independent roles in RIG-I-mediated IFN induction. However, additional regulatory roles are emerging. Here, we show a novel interaction between TRIM25 and another protein in the RLR pathway that is essential for type I IFN induction, DEAD-box helicase 3X (DDX3X). In vitro assays and knockdown studies reveal that TRIM25 ubiquitinates DDX3X at lysine 55 (K55) and that TRIM25 and DDX3X cooperatively enhance IFNB1 induction following RIG-I activation, but the latter is independent of TRIM25's catalytic activity. Furthermore, we found that the influenza A virus non-structural protein 1 (NS1) disrupts the TRIM25:DDX3X interaction, abrogating both TRIM25-mediated ubiquitination of DDX3X and cooperative activation of the IFNB1 promoter. Thus, our results reveal a new interplay between two RLR-host proteins that cooperatively enhance IFN-ß production. We also uncover a new and further mechanism by which influenza A virus NS1 suppresses host antiviral defence.
Assuntos
Antivirais/imunologia , Proteína DEAD-box 58/imunologia , RNA Helicases DEAD-box/imunologia , Imunidade/imunologia , Receptores Imunológicos/imunologia , Fatores de Transcrição/imunologia , Proteínas com Motivo Tripartido/imunologia , Ubiquitina-Proteína Ligases/imunologia , Linhagem Celular , Regulação da Expressão Gênica/imunologia , Células HEK293 , Humanos , Vírus da Influenza A/imunologia , Interferons/imunologia , Regiões Promotoras Genéticas/imunologia , Ligação Proteica/imunologia , Transdução de Sinais/imunologia , Ubiquitinação/imunologiaRESUMO
Rationale: Hosts defend against viral infection by sensing viral pathogen-associated molecular patterns and activating antiviral innate immunity through TBK1-IRF3 signaling. However, the underlying molecular mechanism remains unclear. Methods: SiRNAs targeting Sirt1-7 were transfected into macrophages to screen the antiviral function. Sirt5 deficient mice or macrophages were subjected to viral infection to assess in vivo and in vitro function of Sirt5 by detecting cytokines, viral replicates and survival rate. Immunoprecipitation, WesternBlot and luciferase reporter assay were used to reveal molecular mechanism. Results: In this study, we functionally screened seven Sirtuin family members, and found that Sirtuin5 (Sirt5) promotes antiviral signaling and responses. Sirt5 deficiency leads to attenuated antiviral innate immunity in vivo and in vitro upon viral infection by decreasing TBK1-IRF3 activation and type I IFN production. Sirt5 overexpression increased antiviral innate immunity. Mechanism investigation revealed that Sirt5 interacts with DDX3 and demalonylates DDX3, which is critical for TBK1-IRF3 activation. Mutation of the demalonylation lysine sites (K66, K130, and K162) of DDX3 increased ifnß transcription. Furthermore, the acetylation on lysine 118 of DDX3 positively regulated ifnß transcription, whereas Sirt5 could not deacetylate this site. Conclusion: Sirt5 promotes anti- RNA and DNA virus innate immune responses by increasing TBK1 signaling through demalonylating DDX3, which identifies a novel regulatory pathway of antiviral innate immune response.
Assuntos
RNA Helicases DEAD-box/imunologia , Imunidade Inata , Macrófagos/imunologia , Sirtuínas/imunologia , Estomatite Vesicular/imunologia , Vírus da Estomatite Vesicular Indiana/imunologia , Animais , RNA Helicases DEAD-box/genética , Células HEK293 , Humanos , Lipoilação/genética , Lipoilação/imunologia , Macrófagos/virologia , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Células RAW 264.7 , Sirtuínas/genética , Estomatite Vesicular/genética , Vírus da Estomatite Vesicular Indiana/genéticaRESUMO
DEAD (Glu-Asp-Ala-Glu) box RNA helicases have been proven to contribute to antiviral innate immunity. The DDX21 RNA helicase was identified as a nuclear protein involved in rRNA processing and RNA unwinding. DDX21 was also proven to be the scaffold protein in the complex of DDX1-DDX21-DHX36, which senses double-strand RNA and initiates downstream innate immunity. Here, we identified that DDX21 undergoes caspase-dependent cleavage after virus infection and treatment with RNA/DNA ligands, especially for RNA virus and ligands. Caspase-3/6 cleaves DDX21 at D126 and promotes its translocation from the nucleus to the cytoplasm in response to virus infection. The cytoplasmic cleaved DDX21 negatively regulates the interferon beta (IFN-ß) signaling pathway by suppressing the formation of the DDX1-DDX21-DHX36 complex. Thus, our data identify DDX21 as a regulator of immune balance and most importantly uncover a potential role of DDX21 cleavage in the innate immune response to virus. IMPORTANCE Innate immunity serves as the first barrier against virus infection. DEAD (Glu-Asp-Ala-Glu) box RNA helicases, originally considered to be involved in RNA processing and RNA unwinding, have been shown to play an important role in antiviral innate immunity. The precise regulation of innate immunity is critical for the host because the aberrant production of cytokines leads to unexpected pathological consequences. Here, we identified that DDX21 was cleaved at D126 by virus infection and treatment with RNA/DNA ligands via the caspase-3/6-dependent pathway. The cytoplasmic cleaved DDX21 negatively regulates the IFN-ß signaling pathway by suppressing the formation of the DDX1-DDX21-DHX36 complex. In sum, our data identify DDX21 as a regulator of immune balance and most importantly uncover a potential role of DDX21 cleavage in the innate immune response to virus.
Assuntos
Caspases/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , Imunidade Inata , Viroses/imunologia , Células A549 , Caspases/classificação , Caspases/genética , Linhagem Celular , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Células HEK293 , Células HeLa , Humanos , Interferon beta/imunologia , Ligação Proteica , Transdução de Sinais/imunologia , Células THP-1RESUMO
The management of patients with triple-negative breast cancer (TNBC) continues to pose a significant clinical challenge. Less than 30% of women with metastatic TNBC survive 5 years, despite adjuvant chemotherapy and the initial higher rates of clinical response that can be achieved with neoadjuvant chemotherapy. ImmunoBody is a plasmid DNA designed to encode a human antibody molecule with complementarity-determining regions engineered to express cytotoxic and helper T-cell epitopes derived from the cancer antigen of interest. The helicase antigen (HAGE) is a cancer testis antigen, which is expressed in TNBC. Herein, we have identified a 30-amino-acid-long HAGE-derived sequence containing human leukocyte antigen (HLA)-A2- and HLA-DR1-restricted epitopes and demonstrated that the use of this sequence as a peptide (with CpG/incomplete Freund's adjuvant) or incorporated into an ImmunoBody vaccine can generate specific interferon-γ-secreting splenocytes in HHDII+ DR1+ mice. T-cell responses elicited by the ImmunoBody-HAGE vaccine were superior to peptide immunization. Moreover, splenocytes from ImmunoBody-HAGE-vaccinated mice stimulated in vitro could recognize HAGE+ tumor cells and the human TNBC cell line MDA-MB-231. More importantly, the growth of implanted HHDII+ DR1+ HAGE+ Luc+ B16 cells.
Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer , RNA Helicases DEAD-box/imunologia , Neoplasias de Mama Triplo Negativas , Vacinas de DNA , Animais , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T , Antígeno HLA-A2 , Humanos , Masculino , Camundongos , Linfócitos T , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/terapia , Vacinas de DNA/imunologiaRESUMO
Signaling pathways in innate and adaptive immunity play vital roles in pathogen recognition and the functions of immune cells. Higher-order assemblies have recently emerged as a central principle that governs immune signaling and, by extension, cellular communication in general. There are mainly two types of higher-order assemblies: 1) ordered, solid-like large supramolecular complexes formed by stable and rigid protein-protein interactions, and 2) liquid-like phase-separated condensates formed by weaker and more dynamic intermolecular interactions. This review covers key examples of both types of higher-order assemblies in major immune pathways. By placing emphasis on the molecular structures of the examples provided, we discuss how their structural organization enables elegant mechanisms of signaling regulation.
Assuntos
Imunidade Inata , Inflamassomos/imunologia , Complexos Multiproteicos/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Imunidade Adaptativa , Animais , Proteína DEAD-box 58/genética , Proteína DEAD-box 58/imunologia , Proteína DEAD-box 58/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , RNA Helicases DEAD-box/metabolismo , Regulação da Expressão Gênica , Humanos , Inflamassomos/genética , Inflamassomos/ultraestrutura , Modelos Moleculares , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Conformação Proteica , Mapeamento de Interação de Proteínas , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Receptores Imunológicos/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Toll-Like/genética , Receptores Toll-Like/imunologia , Receptores Toll-Like/metabolismoRESUMO
DEAD-box helicases participate in nearly all steps of an RNA's life. In recent years, increasing evidence has shown that several family members are multitasking enzymes. They are often involved in different processes, which may be typical for RNA helicases, such as RNA export and translation, or atypical, e.g., acting as nucleic acid sensors that activate downstream innate immune signaling. This review focuses on the DEAD-box protein DDX41 and summarizes our current understanding of its roles as an innate immunity sensor in the cytosol and in pre-mRNA splicing in the nucleus and discusses DDX41's involvement in disease.
Assuntos
RNA Helicases DEAD-box/imunologia , Imunidade Inata/imunologia , RNA Mensageiro/imunologia , Humanos , Splicing de RNA/genética , RNA Mensageiro/genéticaRESUMO
DEAD-box helicase 5 (DDX5) plays a significant role in tumorigenesis and regulates viral replication of several viruses. An avian oncogenic herpesvirus, Marek's disease virus (MDV), is widely known to cause immunosuppression and lymphoma in chickens. However, the underlying mechanisms of how DDX5 plays a role in viral replication remain unclear. In this study, we show that MDV inhibits the production of interferon beta (IFN-ß) in chicken embryo fibroblasts (CEFs) by increasing the expression level and promoting the nuclear aggregation of DDX5. We further reveal how DDX5 down-regulates melanoma differentiation-associated gene 5/toll-like receptor 3 signaling through the fundamental transcription factor, interferon regulatory factor 1. MDV replication is suppressed, and the production of IFN-ß is promoted in the DDX5 absented CEFs. Taken together, our investigations demonstrate that MDV inhibits IFN-ß production by targeting DDX5-mediated signaling to facilitate viral replication, which offers a novel insight into the mechanism by which an avian oncogenic herpesvirus replicates in chicken cells.
Assuntos
Proteínas Aviárias/imunologia , RNA Helicases DEAD-box/imunologia , Fibroblastos/imunologia , Herpesvirus Galináceo 2/imunologia , Interferon beta/imunologia , Replicação Viral/imunologia , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Western Blotting , Células Cultivadas , Embrião de Galinha , Galinhas/genética , Galinhas/imunologia , Galinhas/virologia , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Fibroblastos/metabolismo , Fibroblastos/virologia , Regulação da Expressão Gênica/imunologia , Herpesvirus Galináceo 2/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/genética , Imunidade Inata/imunologia , Interferon beta/genética , Interferon beta/metabolismo , Doença de Marek/genética , Doença de Marek/imunologia , Doença de Marek/virologia , RNA-Seq/métodos , Transcriptoma/imunologiaRESUMO
Beyond its well-known canonical function as a tumor suppressor, p53 is also involved in numerous cellular processes through altered transcription under both normal and pathological conditions. The functional diversity of p53 outputs is complex and dependent on cell context. However, the underlying mechanisms responsible for this diversity remain largely unclear. The emerging evidence of p53 mutations involved in regulating endocytic trafficking and signaling, in tandem to promote malignancy (invasion, exosome biogenesis and immune evasion), sheds light on possible mechanisms behind the p53-driven complexity. The interrelated nature of endocytic trafficking and receptor signaling that form dynamic and adaptable feedback loops - either positive or negative - functions to modulate multiple cellular outputs. Biasing the tunable endocytic trafficking and receptor signaling network by mutant p53 expands the purview of p53, allowing its contribution to diverse and aggressive phenotypes. In this review, we explore recent studies in which the novel role of mutant p53 in altering endocytic trafficking to bias receptor signaling and drive transforming phenotypes is revealed. Understanding the complex crosstalk of mutant p53, endocytic trafficking and receptor signaling will allow the development of therapies to selectively target p53-altered endocytic processes.
Assuntos
Endocitose/genética , Mutação com Ganho de Função , Integrina beta1/genética , Neoplasias Pulmonares/genética , Proteína Supressora de Tumor p53/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , Endossomos/genética , Endossomos/metabolismo , Receptores ErbB/genética , Receptores ErbB/imunologia , Regulação Neoplásica da Expressão Gênica , Humanos , Integrina beta1/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Ribonuclease III/genética , Ribonuclease III/imunologia , Transdução de Sinais , Evasão Tumoral , Proteína Supressora de Tumor p53/imunologiaRESUMO
As a member of DExD/H-box helicase family, DDX41 (DEAD box polypeptide 41) acts as an intracellular DNA sensor that induces type I IFN expression in mammals. Fish DDX41 shares some similar properties with the mammalian counterparts. In this study, a DDX41 orthologous gene from grass carp (Ctenopharyngodon idellus) (CiDDX41) was cloned and characterized. The ORF of CiDDX41 encodes a polypeptide of 614 amino acids. Multiple alignments showed that DDX41 is highly conserved among different species. Phylogenetic tree analysis revealed that CiDDX41 shares a high degree of homology with Sinocyclocheilus rhinocerous DDX41. CiDDX41 is highly expressed in kidney, intestines, liver and spleen. Their expressions are up-regulated more obviously after the treatment with GCRV. Over-expression of CiDDX41 in CIK cells increases the transcription level of grass carp IFN I and ISG15. On the contrary, knockdown of CiDDX41 inhibits the IFN I and ISG15 transcription. Moreover, a part of CiDDX41 translocates from the nuclear to cytoplasm to interact with grass carp STING (CiSTING). In CIK cells, overexpression of CiDDX41 and CiSTING can promote the phosphorylation and nuclear-cytoplasm translocation of grass carp IRF7 (CiIRF7) and then acutely up-regulate the IFN I and ISG15 expression. However, the knockdown of CiDDX41 inhibits the phosphorylation IRF7. Taken together, all these results above suggested that CiDDX41 performs as an activator for innate immune through STING-IRF7 mediated signaling pathway.
Assuntos
Carpas/genética , Carpas/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Sequência de Aminoácidos , Animais , Citocinas/química , Citocinas/genética , Citocinas/imunologia , RNA Helicases DEAD-box/química , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , Proteínas de Peixes/química , Perfilação da Expressão Gênica/veterinária , Interferon Tipo I/química , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Filogenia , Alinhamento de Sequência/veterinária , Ubiquitinas/química , Ubiquitinas/genética , Ubiquitinas/imunologiaRESUMO
Faithful maintenance of immune homeostasis relies on the capacity of the cellular immune surveillance machinery to recognize "nonself", such as the presence of pathogenic RNA. Several families of pattern-recognition receptors exist that detect immunostimulatory RNA and then induce cytokine-mediated antiviral and proinflammatory responses. Here, we review the distinct features of bona fide RNA sensors, Toll-like receptors and retinoic-acid inducible gene-I (RIG-I)-like receptors in particular, with a focus on their functional specificity imposed by cell-type-dependent expression, subcellular localization, and ligand preference. Furthermore, we highlight recent advances on the roles of nucleotide-binding oligomerization domain (NOD)-like receptors and DEAD-box or DEAH-box RNA helicases in an orchestrated RNA-sensing network and also discuss the relevance of RNA sensor polymorphisms in human disease.
Assuntos
Imunidade Inata/imunologia , RNA Viral/imunologia , Receptores de Reconhecimento de Padrão/imunologia , Citocinas/imunologia , Proteína DEAD-box 58/genética , Proteína DEAD-box 58/imunologia , Proteína DEAD-box 58/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , RNA Helicases DEAD-box/metabolismo , Humanos , Interferon Tipo I/imunologia , Proteínas NLR/genética , Proteínas NLR/imunologia , Proteínas NLR/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Receptores Imunológicos/metabolismo , Transdução de Sinais/imunologia , Receptores Toll-Like/metabolismoRESUMO
DEAD (Asp-Glu-Ala-Asp) box RNA helicase 3 (DDX3X) is demonstrated to have crucial functions in the antiviral immune response. To our knowledge, little information focuses on the function of duck DDX3X. In this study, duck DDX3X (duDDX3X) was cloned and its role in the type I interferon (IFN) signaling pathway was investigated using duck embryo fibroblast (DEF) cells. Full-length duDDX3X cDNA encodes 652 amino acid residues and contains a DEADc domain and a HELICc domain. According to tissue distribution analysis, duDDX3X mRNA was widely expressed in different tissues, especially the spleen and the liver. Overexpression of duDDX3X in DEF cells induced IFN-ß by activating transcription factors IRF1 and NF-κB. Knockdown of duDDX3X in DEF cells with siRNA significantly reduced IFN-ß expression induced by poly(I:C), a double-stranded RNA (dsRNA) analog. Our results demonstrated that duck DDX3X was involved in the dsRNA-mediated type I IFN signaling pathway in DEF cells.
Assuntos
Proteínas Aviárias/genética , RNA Helicases DEAD-box/genética , Patos/genética , Sequência de Aminoácidos , Animais , Proteínas Aviárias/análise , Proteínas Aviárias/imunologia , Clonagem Molecular , RNA Helicases DEAD-box/análise , RNA Helicases DEAD-box/imunologia , DNA Complementar/genética , Patos/imunologia , Imunidade Inata , Interferon beta/imunologia , Modelos Moleculares , NF-kappa B/imunologia , Filogenia , Transdução de SinaisRESUMO
The human ovary orchestrates sex hormone production and undergoes monthly structural changes to release mature oocytes. The outer lining of the ovary (cortex) has a key role in defining fertility in women as it harbors the ovarian reserve. It has been postulated that putative oogonial stem cells exist in the ovarian cortex and that these can be captured by DDX4 antibody isolation. Here, we report single-cell transcriptomes and cell surface antigen profiles of over 24,000 cells from high quality ovarian cortex samples from 21 patients. Our data identify transcriptional profiles of six main cell types; oocytes, granulosa cells, immune cells, endothelial cells, perivascular cells, and stromal cells. Cells captured by DDX4 antibody are perivascular cells, not oogonial stem cells. Our data do not support the existence of germline stem cells in adult human ovaries, thereby reinforcing the dogma of a limited ovarian reserve.
Assuntos
Células-Tronco de Oogônios , Ovário/citologia , Análise de Célula Única/métodos , Adulto , Biomarcadores/metabolismo , Células Cultivadas , RNA Helicases DEAD-box/imunologia , RNA Helicases DEAD-box/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Procedimentos de Readequação Sexual , TranscriptomaRESUMO
DEAD-box helicases are a large family of conserved RNA-binding proteins that belong to the broader group of cellular DExD/H helicases. Members of the DEAD-box helicase family have roles throughout cellular RNA metabolism from biogenesis to decay. Moreover, there is emerging evidence that cellular RNA helicases, including DEAD-box helicases, play roles in the recognition of foreign nucleic acids and the modulation of viral infection. As intracellular parasites, viruses must evade detection by innate immune sensing mechanisms and degradation by cellular machinery while also manipulating host cell processes to facilitate replication. The ability of DEAD-box helicases to recognize RNA in a sequence-independent manner, as well as the breadth of cellular functions carried out by members of this family, lead them to influence innate recognition and viral infections in multiple ways. Indeed, DEAD-box helicases have been shown to contribute to intracellular immune sensing, act as antiviral effectors, and even to be coopted by viruses to promote their replication. However, our understanding of the mechanisms underlying these interactions, as well as the cellular roles of DEAD-box helicases themselves, is limited in many cases. We will discuss the diverse roles that members of the DEAD-box helicase family play during viral infections.