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Qin Fang - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Aquareovirus NS80 Initiates Efficient Viral Replication by Retaining Core Proteins within Replication-Associated Viral Inclusion Bodies
2016Co-Authors: Qin FangAbstract:Viral Inclusion Bodies (VIBs) are specific intracellular compartments for reoviruses replica-tion and assembly. Aquareovirus nonstructural protein NS80 has been identified to be the major constituent for forming globular VIBs in our previous study. In this study, we investi-gated the role of NS80 in Viral structural proteins expression and Viral replication. Immuno-fluorescence assays showed that NS80 could retain five core proteins or inner-capsid proteins (VP1-VP4 and VP6), but not outer-capsid proteins (VP5 and VP7), within VIBs in co-transfected or infected cells. Further co-immunoprecipitation analysis confirmed that NS80 could interact with each core protein respectively. In addition, we found that newly synthesized Viral RNAs co-localized with VIBs. Furthermore, time-course analysis of Viral structural proteins expression showed that the expression of NS80 was detected first, fol-lowed by the detection of inner shell protein VP3, and then of other inner-capsid proteins, suggesting that VIBs were essential for the formation of Viral core frame or progeny virion. Moreover, knockdown of NS80 by shRNA not only inhibited the expression of aquareovirus structural proteins, but also inhibited Viral infection. These results indicated that NS80-based VIBs were formed at earlier stage of infection, and NS80 was able to coordinate the expression of Viral structural proteins and Viral replication
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The N-Terminal of Aquareovirus NS80 Is Required for Interacting with Viral Proteins and Viral Replication
PloS one, 2016Co-Authors: Jie Zhang, Hong Guo, Qingxiu Chen, Fuxian Zhang, Qin FangAbstract:Reovirus replication and assembly occurs within Viral Inclusion Bodies that formed in specific intracellular compartments of cytoplasm in infected cells. Previous study indicated that aquareovirus NS80 is able to form Inclusion Bodies, and also can retain Viral proteins within its Inclusions. To better understand how NS80 performed in Viral replication and assembly, the functional regions of NS80 associated with other Viral proteins in aquareovirus replication were investigated in this study. Deletion mutational analysis and rotavirus NSP5-based protein association platform were used to detect association regions. Immunofluorescence images indicated that different N-terminal regions of NS80 could associate with Viral proteins VP1, VP4, VP6 and NS38. Further co-immunoprecipitation analysis confirmed the interaction between VP1, VP4, VP6 or NS38 with different regions covering the N-terminal amino acid (aa, 1-471) of NS80, respectively. Moreover, removal of NS80 N-terminal sequences required for interaction with proteins VP1, VP4, VP6 or NS38 not only prevented the capacity of NS80 to support Viral replication in NS80 shRNA-based replication complementation assays, but also inhibited the expression of aquareovirus proteins, suggesting that N-terminal regions of NS80 are necessary for Viral replication. These results provided a foundational basis for further understanding the role of NS80 in Viral replication and assembly during aquareovirus infection.
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Construction of NSP5-based protein association platform.
2016Co-Authors: Jie Zhang, Hong Guo, Qingxiu Chen, Fuxian Zhang, Qin FangAbstract:(A) Principle of the NSP5-based protein association platform. Plasmids expressing NS80 fragments (bait protein) fused to GFP-NSP5 and Viral proteins (prey protein) are co-transfected into Vero cells. If prey protein associate with bait protein, it will be recruited into Viral Inclusion Bodies. (B) NS80 and GFP-fused NSP5 form non-overlapping structures. Vero cells co-transfected with pCI-neo-NS80 and either GFP-NSP5 or NS38-GFP-NSP5 were fixed at 24 h post-transfection. Viral Inclusion Bodies were visualized by staining with NS80 pAbs followed by Alexa 568-conjugated donkey anti-rabbit IgG (red). Cell nuclei (blue) were stained with DAPI. (C and D) Vero cells were transfected with GFP-NS80, GFP-NSP5, or NS38-GFP-NSP5. At 24 h post-transfection, cells were fixed and stained with poly-ubiquitin or vimentin pAbs, and then followed by Alexa Fluor® 568-conjugated donkey anti-rabbit IgG (red). Cell nuclei (blue) were stained with DAPI. The images were obtained by fluorescence microscopy using a 40 × objective.
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aquareovirus ns80 initiates efficient Viral replication by retaining core proteins within replication associated Viral Inclusion Bodies
PLOS ONE, 2015Co-Authors: Liming Yan, Jie Zhang, Hong Guo, Qingxiu Chen, Fuxian Zhang, Shicui Yan, Qin FangAbstract:Viral Inclusion Bodies (VIBs) are specific intracellular compartments for reoviruses replication and assembly. Aquareovirus nonstructural protein NS80 has been identified to be the major constituent for forming globular VIBs in our previous study. In this study, we investigated the role of NS80 in Viral structural proteins expression and Viral replication. Immunofluorescence assays showed that NS80 could retain five core proteins or inner-capsid proteins (VP1-VP4 and VP6), but not outer-capsid proteins (VP5 and VP7), within VIBs in co-transfected or infected cells. Further co-immunoprecipitation analysis confirmed that NS80 could interact with each core protein respectively. In addition, we found that newly synthesized Viral RNAs co-localized with VIBs. Furthermore, time-course analysis of Viral structural proteins expression showed that the expression of NS80 was detected first, followed by the detection of inner shell protein VP3, and then of other inner-capsid proteins, suggesting that VIBs were essential for the formation of Viral core frame or progeny virion. Moreover, knockdown of NS80 by shRNA not only inhibited the expression of aquareovirus structural proteins, but also inhibited Viral infection. These results indicated that NS80-based VIBs were formed at earlier stage of infection, and NS80 was able to coordinate the expression of Viral structural proteins and Viral replication.
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aquareovirus ns80 recruits Viral proteins to its Inclusions and its c terminal domain is the primary driving force for Viral Inclusion formation
PLOS ONE, 2013Co-Authors: Ling Shao, Hong Guo, Liming Yan, Huan Liu, Qin FangAbstract:Cytoplasmic Inclusion Bodies formed in reovirus-infected cells are the sites of Viral replication and assembly. Previous studies have suggested that the NS80 protein of aquareovirus may be involved in the formation of Viral Inclusion Bodies. However, it remains unknown whether other Viral proteins are involved in the process, and what regions of NS80 may act coordinately in mediating Inclusion formation. Here, we observed that globular cytoplasmic Inclusions were formed in virus-infected cells and Viral proteins NS80 and NS38 colocalized in the Inclusions. During transfection, singly expressed NS80 could form cytoplasmic Inclusions and recruit NS38 and GFP-tagged VP4 to these structures. Further treatment of cells with nocodazole, a microtubule inhibitor, did not disrupt the Inclusion, suggesting that Inclusion formation does not rely on microtubule network. Besides, we identified that the region 530–742 of NS80 was likely the minimal region required for Inclusion formation, and the C-tail, coiled-coil region as well as the conserved linker region were essential for Inclusion phenotype. Moreover, with series deletions from the N-terminus, a stepwise conversion occurred from large condensed cytoplasmic to small nuclear Inclusions, then to a diffused intracellular distribution. Notablely, we found that the nuclear Inclusions, formed by NS80 truncations (471 to 513–742), colocalized with cellular protein β-catenin. These data indicated that NS80 could be a major mediator in recruiting NS38 and VP4 into Inclusion structures, and the C-terminus of NS80 is responsible for Inclusion formation.
Tsunekazu Hishima - One of the best experts on this subject based on the ideXlab platform.
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unusual manifestation of disseminated herpes simplex virus type 2 infection associated with pharyngotonsilitis esophagitis and hemophagocytic lymphohisitocytosis without genital involvement
BMC Infectious Diseases, 2019Co-Authors: Shuhei Kurosawa, Noritaka Sekiya, Kazuaki Fukushima, Kazuhiko Ikeuchi, Akito Fukuda, Hideyuki Takahashi, Fangyi Chen, Hideki Hasegawa, Harutaka Katano, Tsunekazu HishimaAbstract:Herpes simplex virus (HSV) has various presentations, depending on the patient’s immune status, age, and the route of transmission. In adults, HSV type 1 is found predominantly in the oral area, and HSV type 2 (HSV-2) is commonly found in the genital area. HSV-2 infection without genital lesions is uncommon. Herein we report a unique case of pharyngotonsillitis as an initial manifestation of disseminated HSV-2 infection without genital involvement. A 46-year-old male was admitted to our hospital with a 1-week history of fever and sore throat. His past medical history included hypereosinophilic syndrome diagnosed at age 45 years. Physical examination revealed throat congestion, bilaterally enlarged tonsils with exudates, tender cervical lymphadenopathy in the left posterior triangle, and mild epigastric tenderness. The laboratory data demonstrated bicytopenia, elevated liver enzyme levels, and hyperferritinemia. A bone marrow smear showed hypocellular marrow with histiocytes and hemophagocytosis. The diagnosis of HLH was confirmed, and the patient was treated with methylprednisolone pulse therapy on days 1–3. On day 5, despite initial improvement of the fever and sore throat, multiple, new, small bullae developed on the patient’s face, trunk, and extremities. Additional testing showed that he was positive for HSV-specific immunoglobulin M and immunoglobulin G. Disseminated HSV infection was suspected, and intravenous acyclovir (10 mg/kg every 8 h) was begun. A subsequent direct antigen test of a bulla sample was positive for HSV-2. Moreover, tonsillar and esophageal biopsies revealed Viral Inclusion Bodies. Immunohistochemical staining and a quantitative real-time polymerase chain reaction (PCR) assay confirmed the presence of HSV-2. Disseminated HSV-2 infection with multiple bullae, tonsillitis, esophagitis, and suspected hepatic involvement was diagnosed. After a 2-week course of intravenous acyclovir, his hematological status and liver function normalized, and his cutaneous skin lesions resolved. He was discharged on day 22 in good general health and continued taking oral valacyclovir for Viral suppression due to his immunosuppressed status. Disseminated HSV-2 infection should be considered as one of the differential diagnoses in patients with pharyngotonsillitis and impaired liver function of unknown etiology even if there are no genital lesions.
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Unusual manifestation of disseminated herpes simplex virus type 2 infection associated with pharyngotonsilitis, esophagitis, and hemophagocytic lymphohisitocytosis without genital involvement
BMC, 2019Co-Authors: Shuhei Kurosawa, Noritaka Sekiya, Kazuaki Fukushima, Kazuhiko Ikeuchi, Akito Fukuda, Hideyuki Takahashi, Fangyi Chen, Hideki Hasegawa, Harutaka Katano, Tsunekazu HishimaAbstract:Abstract Background Herpes simplex virus (HSV) has various presentations, depending on the patient’s immune status, age, and the route of transmission. In adults, HSV type 1 is found predominantly in the oral area, and HSV type 2 (HSV-2) is commonly found in the genital area. HSV-2 infection without genital lesions is uncommon. Herein we report a unique case of pharyngotonsillitis as an initial manifestation of disseminated HSV-2 infection without genital involvement. Case presentation A 46-year-old male was admitted to our hospital with a 1-week history of fever and sore throat. His past medical history included hypereosinophilic syndrome diagnosed at age 45 years. Physical examination revealed throat congestion, bilaterally enlarged tonsils with exudates, tender cervical lymphadenopathy in the left posterior triangle, and mild epigastric tenderness. The laboratory data demonstrated bicytopenia, elevated liver enzyme levels, and hyperferritinemia. A bone marrow smear showed hypocellular marrow with histiocytes and hemophagocytosis. The diagnosis of HLH was confirmed, and the patient was treated with methylprednisolone pulse therapy on days 1–3. On day 5, despite initial improvement of the fever and sore throat, multiple, new, small bullae developed on the patient’s face, trunk, and extremities. Additional testing showed that he was positive for HSV-specific immunoglobulin M and immunoglobulin G. Disseminated HSV infection was suspected, and intravenous acyclovir (10 mg/kg every 8 h) was begun. A subsequent direct antigen test of a bulla sample was positive for HSV-2. Moreover, tonsillar and esophageal biopsies revealed Viral Inclusion Bodies. Immunohistochemical staining and a quantitative real-time polymerase chain reaction (PCR) assay confirmed the presence of HSV-2. Disseminated HSV-2 infection with multiple bullae, tonsillitis, esophagitis, and suspected hepatic involvement was diagnosed. After a 2-week course of intravenous acyclovir, his hematological status and liver function normalized, and his cutaneous skin lesions resolved. He was discharged on day 22 in good general health and continued taking oral valacyclovir for Viral suppression due to his immunosuppressed status. Conclusion Disseminated HSV-2 infection should be considered as one of the differential diagnoses in patients with pharyngotonsillitis and impaired liver function of unknown etiology even if there are no genital lesions
M J Mihatsch - One of the best experts on this subject based on the ideXlab platform.
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polyomavirus nephropathy in native kidneys and renal allografts an update on an escalating threat
Transplant International, 2006Co-Authors: Volker Nickeleit, M J MihatschAbstract:Summary Polyomavirus nephropathy, also termed BK-virus nephropathy (BKN) after the main causative agent, the polyoma-BK-virus strain, is a significant complication after kidney transplantation. BKN is the most common Viral infection that affects renal allografts with a prevalence of 1–9% on average 8–13 months post surgery. It can also occur sporadically in native kidneys. Viral nephropathy is caused by the (re)activation of latent BK viruses that enter into a replicative cycle under sustained and intensive immunosuppression. Pure productive kidney infections with JC- and SV-40 polyomaviruses are exceptionally rare. BKN is morphologically defined by the presence of intranuclear Viral Inclusion Bodies in epithelial cells and tubular injury, which is the morphological correlate for renal dysfunction. Renal disease can progress through different histologic stages (from early BKN stage A to late fibrotic stage C) that carry prognostic significance; disease stages B and C often result in chronic kidney (allograft) dysfunction and end-stage renal disease. The clinical goal is to diagnose Viral nephropathy in disease stage A and to limit chronic renal injury. Strategies to recognize, classify, and manage BKN are critically discussed including ancillary techniques for risk assessment and patient monitoring: (i) urine cytology and the search for so-called ‘decoy cells’; (ii) PCR analyses for Viral load measurements in the plasma and urine; and (iii) negative staining urine electron microscopy to identify Viral particles.
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testing for polyomavirus type bk dna in plasma to identify renal allograft recipients with Viral nephropathy
The New England Journal of Medicine, 2000Co-Authors: Volker Nickeleit, Peter Dalquen, Thomas Klimkait, M J Mihatsch, Isabelle Binet, Veronika Del Zenero, G Thiel, Hans H HirschAbstract:Background Reactivation of polyomavirus type BK (BK virus) is increasingly recognized as a cause of severe renal-allograft dysfunction. Currently, patients at risk for nephropathy due to infection with the BK virus are identified by the presence of cells containing Viral Inclusion Bodies (“decoy cells”) in the urine or by biopsy of allograft tissue. Methods In a retrospective analysis, we performed polymerase-chain-reaction assays for BK virus DNA in plasma samples from 9 renal-allograft recipients with BK virus nephropathy; 41 renal-allograft recipients who did not have signs of nephropathy, 16 of whom had decoy cells in the urine; and as immunocompromised controls, 17 patients who had human immunodeficiency virus type 1 (HIV-1) infection (stage C3 according to the classification of the Centers for Disease Control and Prevention) and who had not undergone transplantation. Results In all nine patients with BK virus nephropathy, BK virus DNA was detected in the plasma at the time of the initial histologic ...
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polyomavirus infection of renal allograft recipients from latent infection to manifest disease
Journal of The American Society of Nephrology, 1999Co-Authors: Volker Nickeleit, Hans H Hirsch, Peter Dalquen, Isabelle Binet, G Thiel, F Gudat, Olivier Prince, M J MihatschAbstract:Abstract . Polyomavirus (PV) exceptionally causes a morphologically manifest renal allograft infection. Five such cases were encountered in this study, and were followed between 40 and 330 d during persistent PV renal allograft infection. Transplant (Tx) control groups without PV graft infection were analyzed for comparison. Tissue and urine samples were evaluated by light microscopy, immunohistochemistry, electron microscopy, and PCR. The initial diagnosis of PV infection with the BK strain was made in biopsies 9 ± 2 mo (mean ± SD) post-Tx after prior rejection episodes and rescue therapy with tacrolimus. All subsequent biopsies showed persistent PV infection. Intranuclear Viral Inclusion Bodies in epithelial cells along the entire nephron and the transitional cell layer were histologic hallmarks of infection. Affected tubular cells were enlarged and often necrotic. In two patients, small glomerular crescents were found. In 54% of biopsies, infection was associated with pronounced inflammation, which had features of cellular rejection. All patients were excreting PV-infected cells in the urine. PV infection was associated with 40% graft loss (2 of 5) and a serum creatinine of 484 ± 326 μmol/L (mean ± SD; 11 mo post-Tx). Tx control groups showed PV-infected cells in the urine in 5%. Control subjects had fewer rejection episodes ( P P = 0.01). It is concluded that a manifest renal allograft infection with PV (BK strain) can persist in heavily immunosuppressed patients with recurrent rejection episodes. PV mainly affects tubular cells and causes necrosis, a major reason for functional deterioration. A biopsy is required for diagnosis. Urine cytology can serve as an adjunct diagnostic tool.
Polly Roy - One of the best experts on this subject based on the ideXlab platform.
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cellular casein kinase 2 and protein phosphatase 2a modulate replication site assembly of bluetongue virus
Journal of Biological Chemistry, 2016Co-Authors: Bjornpatrick Mohl, Polly RoyAbstract:A number of cytoplasmic replicating viruses produce cytoplasmic Inclusion Bodies or protein aggregates; however, a hallmark of viruses of the Reoviridae family is that they utilize these sites for purposes of replication and capsid assembly, functioning as Viral assembly factories. Here we have used bluetongue virus (BTV) as a model system for this broad family of important viruses to understand the mechanisms regulating Inclusion body assembly. Newly synthesized Viral proteins interact with sequestered Viral RNA molecules prior to capsid assembly and double-stranded RNA synthesis within Viral Inclusion Bodies (VIBs). VIBs are predominantly comprised of a BTV-encoded non-structural protein 2 (NS2). Previous in vitro studies indicated that casein kinase 2 (CK2) mediated the phosphorylation of NS2, which regulated the propensity of NS2 to form larger aggregates. Using targeted pharmacological reagents, specific mutation in the Viral genome by reverse genetics and confocal microscopy, here we demonstrate that CK2 activity is important for BTV replication. Furthermore, we show that a novel host cell factor, protein phosphatase 2A, is involved in NS2 dephosphorylation and that, together with CK2, it regulates VIB morphology and virus replication. Thus, these two host enzymes influence the dynamic nature of VIB assembly/disassembly, and these concerted activities may be relevant to the assembly and the release of these cores from VIBs.
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phosphorylation of bluetongue virus nonstructural protein 2 is essential for formation of Viral Inclusion Bodies
Journal of Virology, 2005Co-Authors: Jens Modrof, Polly Roy, Kostas LymperopoulosAbstract:In bluetongue virus (BTV)-infected cells, large cytoplasmic aggregates are formed, termed Viral Inclusion Bodies (VIBs), which are believed to be the sites of Viral replication and morphogenesis. The BTV nonstructural protein NS2 is the major component of VIBs. NS2 undergoes intracellular phosphorylation and possesses a strong single-stranded RNA binding activity. By changing phosphorylated amino acids to alanines and aspartates, we have mapped the phosphorylated sites of NS2 to two serine residues at positions 249 and 259. Since both of these serines are within the context of protein kinase CK2 recognition signals, we have further examined if CK2 is involved in NS2 phosphorylation by both intracellular colocalization and an in vitro phosphorylation assay. In addition, we have utilized the NS2 mutants to determine the role of phosphorylation on NS2 activities. The data obtained demonstrate that NS2 phosphorylation is not necessary either for its RNA binding properties or for its ability to interact with the Viral polymerase VP1. However, phosphorylated NS2 exhibited VIB formation while unmodified NS2 failed to assemble as VIBs although smaller oligomeric forms of NS2 were readily formed. Our data reveal that NS2 phosphorylation controls VIBs formation consistent with a model in which NS2 provides the matrix for Viral assembly.
Zheng Xing - One of the best experts on this subject based on the ideXlab platform.
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suppression of the ifn α and β induction through sequestering irf7 into Viral Inclusion Bodies by nonstructural protein nss in severe fever with thrombocytopenia syndrome bunyavirus infection
Journal of Immunology, 2019Co-Authors: Ye Hong, Xian Qi, Mifang Liang, Carol J Cardona, Dexin Li, Chuan Li, Zheng XingAbstract:Induction of type I IFNs during Viral infection is crucial for host defense. IRF 3 and IRF7 play a critical role as key transcription factors in the activation of the IFN induction. Viruses have evolved a variety of strategies to evade innate immunity. Our previous studies have shown that the nonstructural protein (NSs) of the severe fever with thrombocytopenia syndrome virus (SFTSV) can suppress the IFN-β induction through its interaction with tank-binding kinase-1 and sequestering the inhibitor of nuclear factor kappa B kinase(IKK) complex into the Inclusion Bodies formed by NSs. In this study, we characterized the unique function of IRF7 in innate immunity and its role in inducing IFN-α in particular, regulated by NSs during the SFTSV infection in several cell types of human origin. Whereas IRF3 is constitutively expressed, IRF7 was significantly induced differentially in various cell types in response to SFTSV infection, promoted the induction of IFN-α2 and -α4, and further induced IFN-β, thus contributing to suppressing the Viral replication. Our data indicate that NSs directly interacted with and sequestered IRF7 into the Inclusion Bodies, which is different from IRF3 indirectly interacting with NSs. Although interaction of NSs with IRF7 did not inhibit IRF7 phosphorylation, p-IRF7 was trapped in the Inclusion Bodies, resulting in a significant reduction of the IFN-α2 and -α4 induction and therefore enhanced Viral replication. Interaction of the Viral NSs with both IRF7 and IRF3 and subsequent sequestration of these transcription factors into Viral Inclusion Bodies, a unique strategy used by this phlebovirus, may ensure effective evasion and suppression of host innate immunity.
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roles of Viral Inclusion Bodies in innate immune evasion in infection with a novel bunyavirus inm8p 441
Journal of Immunology, 2014Co-Authors: Mifang Liang, Zheng Xing, Carol J CardonaAbstract:Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus in the family Bunyaviridae. We have previously shown that innate immunity in host cells was modulated in infected cells and antiViral cytokine induction was suppressed by nonstructural protein NSs of SFTSV. In this study, we analyzed the pattern recognition receptors and the signaling pathways for mounting innate defense against viruses. Through studying virus-host interactions, we have explored the strategy exploited by SFTSV to evade host antiViral responses. We found that NSs can form Inclusion Bodies in infected cells. Viral Inclusion Bodies (IBs), which are accumulated aggregates of Viral proteins, are commonly formed during Viral replication in infected cells, but their role in Viral immune evasion has barely been explored. Interestingly NSs interacted with multiple players in the signaling pathways. Through interacting with tank-binding kinase 1 (TBK1), NSs was able to sequester the IKK complex, including IKKϵ and IRF3 into IBs, albeit NSs did not interact with IKKϵ or IRF3 directly. In the presence of NSs, IRF3 could still be phosphorylated, but p-IRF3 was trapped into cytoplasmic IBs in SFTSV-infected cells; consequently, IFN-β induction was reduced and Viral replication enhanced. Sequestering IKK complex, active IRF3, and other signaling molecules into Viral IBs resulting in a reduced IFN response, is a novel mechanism for viruses to evade innate immunity.
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evasion of antiViral immunity through sequestering of tbk1 ikke irf3 into Viral Inclusion Bodies
Journal of Virology, 2014Co-Authors: Zerui Zhang, Mifang Liang, Carol J Cardona, Zheng XingAbstract:Cells are equipped with pattern recognition receptors (PRRs) such as the Toll-like and RIG-I-like receptors that mount innate defenses against viruses. However, viruses have evolved multiple strategies to evade or thwart host antiViral responses. Viral Inclusion Bodies (IBs), which are accumulated aggregates of Viral proteins, are commonly formed during the replication of some viruses in infected cells, but their role in Viral immune evasion has rarely been explored. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus in the Bunyaviridae. The SFTS Viral nonstructural protein NSs can suppress host beta interferon (IFN-β) responses. NSs can form IBs in infected and transfected cells. Through interaction with tank-binding kinase 1 (TBK1), Viral NSs was able to sequester the IKK complex, including IKKe and IRF3, into IBs, although NSs did not interact with IKKe or IRF3 directly. When cells were infected with influenza A virus, IRF3 was phosphorylated and active phosphorylated IRF3 (p-IRF3) was translocated into the nucleus. In the presence of NSs, IRF3 could still be phosphorylated, but p-IRF3 was trapped in cytoplasmic IBs, resulting in reduced IFN-β induction and enhanced Viral replication. Sequestration of the IKK complex and active IRF3 into Viral IBs through the interaction of NSs and TBK1 is a novel mechanism for Viral evasion of innate immunity.
