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Zhang Z, Zhang H, Luo Q, Zheng Y, Kong W, Huang L, Zhao M. Variations in NSP1 of Porcine Reproductive and Respiratory Syndrome Virus Isolated in China from 1996 to 2022. Genes (Basel) 2023; 14:1435. [PMID: 37510339 PMCID: PMC10379836 DOI: 10.3390/genes14071435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Since its successful isolation in China in 1995, the porcine reproductive and respiratory syndrome virus (PRRSV) has been mutating into highly pathogenic strains by constantly changing pathogenicity and genetic makeup. In this study, we investigated the prevalence and genetic variation of nonstructural protein 1 (NSP1) in PRRSV-2, the main strain prevalent in China. After formulating hypotheses regarding the biology of the NSP1 protein, the nucleotide and amino acid similarity of NSP1 were analyzed and compared in 193 PRRSV-2 strains. The results showed that NSP1 has a stable hydrophobic protein with a molecular weight of 43,060.76 Da. Although NSP1 lacked signal peptides, it could regulate host cell signaling. Furthermore, NSP1 of different strains had high nucleotide (79.6-100%) and amino acid similarity (78.6-100%). In the amino acid sequence comparison of 15 representative strains of PRRSV-2, multiple amino acid substitution sites were found in NSP1. Phylogenetic tree analysis showed that lineages 1 and 8 had different evolutionary branches with long genetic distances. This study lays the foundation for an in-depth understanding of the nature and genetic variation of NSP1 and the development of a safe and effective vaccine in the future.
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Affiliation(s)
- Zhiqing Zhang
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
| | - Hang Zhang
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
| | - Qin Luo
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
| | - Yajie Zheng
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
| | - Weili Kong
- Gladstone Institutes of Virology and Immunology, University of California, San Francisco, CA 94158, USA;
| | - Liangzong Huang
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
| | - Mengmeng Zhao
- School of Life Science and Engineering, Foshan University, Foshan 528000, China; (Z.Z.); (Q.L.); (Y.Z.)
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Su CM, Du Y, Rowland RRR, Wang Q, Yoo D. Reprogramming viral immune evasion for a rational design of next-generation vaccines for RNA viruses. Front Immunol 2023; 14:1172000. [PMID: 37138878 PMCID: PMC10149994 DOI: 10.3389/fimmu.2023.1172000] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/03/2023] [Indexed: 05/05/2023] Open
Abstract
Type I interferons (IFNs-α/β) are antiviral cytokines that constitute the innate immunity of hosts to fight against viral infections. Recent studies, however, have revealed the pleiotropic functions of IFNs, in addition to their antiviral activities, for the priming of activation and maturation of adaptive immunity. In turn, many viruses have developed various strategies to counteract the IFN response and to evade the host immune system for their benefits. The inefficient innate immunity and delayed adaptive response fail to clear of invading viruses and negatively affect the efficacy of vaccines. A better understanding of evasion strategies will provide opportunities to revert the viral IFN antagonism. Furthermore, IFN antagonism-deficient viruses can be generated by reverse genetics technology. Such viruses can potentially serve as next-generation vaccines that can induce effective and broad-spectrum responses for both innate and adaptive immunities for various pathogens. This review describes the recent advances in developing IFN antagonism-deficient viruses, their immune evasion and attenuated phenotypes in natural host animal species, and future potential as veterinary vaccines.
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Affiliation(s)
- Chia-Ming Su
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Yijun Du
- Shandong Key Laboratory of Animal Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Raymond R. R. Rowland
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Qiuhong Wang
- Center for Food Animal Health, Department of Animal Sciences, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Wooster, OH, United States
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Dongwan Yoo
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- *Correspondence: Dongwan Yoo,
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3
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Signaling Lymphocytic Activation Molecule Family Member 1 Inhibits Porcine Reproductive and Respiratory Syndrome Virus Replication. Animals (Basel) 2022; 12:ani12243542. [PMID: 36552462 PMCID: PMC9774311 DOI: 10.3390/ani12243542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) causes a highly contagious disease in domestic swine. Signaling lymphocytic activation molecule family member 1 (SLAMF1) is a costimulatory factor that is involved in innate immunity, inflammation, and infection. Here, we demonstrate that overexpression of the SLAMF1 gene inhibited PRRSV replication significantly and reduced the levels of key signaling pathways, including MyD88, RIG-I, TLR2, TRIF, and inflammatory factors IL-6, IL-1β, IL-8, TNF-β, TNF-α, and IFN-α in vitro. However, the knockdown of the SLAMF1 gene could enhance replication of the PRRSV and the levels of key signaling pathways and inflammatory factors. Overall, our results identify a new, to our knowledge, antagonist of the PRRSV, as well as a novel antagonistic mechanism evolved by inhibiting innate immunity and inflammation, providing a new reference and direction for PRRSV disease resistance breeding.
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A New Long Noncoding RNA, MAHAT, Inhibits Replication of Porcine Reproductive and Respiratory Syndrome Virus by Recruiting DDX6 To Bind to ZNF34 and Promote an Innate Immune Response. J Virol 2022; 96:e0115422. [PMID: 36073922 PMCID: PMC9517731 DOI: 10.1128/jvi.01154-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) have increasingly been recognized as being integral to cellular processes, including the antiviral immune response. Porcine reproductive and respiratory syndrome virus (PRRSV) is costly to the global swine industry. To identify PRRSV-related lncRNAs, we performed RNA deep sequencing and compared the profiles of lncRNAs in PRRSV-infected and uninfected Marc-145 cells. We identified a novel lncRNA called MAHAT (maintaining cell morphology-associated and highly conserved antiviral transcript; LTCON_00080558) that inhibits PRRSV replication. MAHAT binds and negatively regulates ZNF34 expression by recruiting and binding DDX6, an RNA helicase forming a complex with ZNF34. Inhibition of ZNF34 expression results in increased type I interferon expression and decreased PRRSV replication. This finding reveals a novel mechanism by which PRRSV evades the host antiviral innate immune response by downregulating the MAHAT-DDX6-ZNF34 pathway. MAHAT could be a host factor target for antiviral therapies against PRRSV infection. IMPORTANCE Long noncoding RNAs (lncRNAs) play important roles in viral infection by regulating the transcription and expression of host genes, and interferon signaling pathways. Porcine reproductive and respiratory syndrome virus (PRRSV) causes huge economic losses in the swine industry worldwide, but the mechanisms of its pathogenesis and immunology are not fully understood. Here, a new lncRNA, designated MAHAT, was identified as a regulator of host innate immune responses. MAHAT negatively regulates the expression of its target gene, ZNF34, by recruiting and binding DDX6, an RNA helicase, forming a complex with ZNF34. Inhibition of ZNF34 expression increases type I interferon expression and decreases PRRSV replication. This finding suggests that MAHAT has potential as a new target for developing antiviral drugs against PRRSV infection.
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Mapping the Key Residues within the Porcine Reproductive and Respiratory Syndrome Virus nsp1α Replicase Protein Required for Degradation of Swine Leukocyte Antigen Class I Molecules. Viruses 2022; 14:v14040690. [PMID: 35458420 PMCID: PMC9030574 DOI: 10.3390/v14040690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 02/05/2023] Open
Abstract
The nonstructural protein 1α (nsp1α) of the porcine reproductive and respiratory syndrome virus (PRRSV) has been shown to target swine leukocyte antigen class I (SLA-I) for degradation, but the molecular details remain unclear. In this report, we further mapped the critical residues within nsp1α by site-directed mutagenesis. We identified a cluster of residues (i.e., Phe17, Ile81, Phe82, Arg86, Thr88, Gly90, Asn91, Phe94, Arg97, Thr160, and Asn161) necessary for this function. Interestingly, they are all located in a structurally relatively concentrated region. Further analysis by reverse genetics led to the generation of two viable viral mutants, namely, nsp1α-G90A and nsp1α-T160A. Compared to WT, nsp1α-G90A failed to co-localize with either chain of SLA-I within infected cells, whereas nsp1α-T160A exhibited a partial co-localization relationship. Consequently, the mutant nsp1α-G90A exhibited an impaired ability to downregulate SLA-I in infected macrophages as demonstrated by Western blot, indirect immunofluorescence, and flow cytometry analysis. Consistently, the ubiquitination level of SLA-I was significantly reduced in the conditions of both infection and transfection. Together, our results provide further insights into the mechanism underlying PRRSV subversion of host immunity and have important implications in vaccine development.
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Cook GM, Brown K, Shang P, Li Y, Soday L, Dinan AM, Tumescheit C, Mockett APA, Fang Y, Firth AE, Brierley I. Ribosome profiling of porcine reproductive and respiratory syndrome virus reveals novel features of viral gene expression. eLife 2022; 11:e75668. [PMID: 35226596 PMCID: PMC9000960 DOI: 10.7554/elife.75668] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/26/2022] [Indexed: 11/13/2022] Open
Abstract
The arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic losses to the swine industry worldwide. Here we apply ribosome profiling (RiboSeq) and parallel RNA sequencing (RNASeq) to characterise the transcriptome and translatome of both species of PRRSV and to analyse the host response to infection. We calculated programmed ribosomal frameshift (PRF) efficiency at both sites on the viral genome. This revealed the nsp2 PRF site as the second known example where temporally regulated frameshifting occurs, with increasing -2 PRF efficiency likely facilitated by accumulation of the PRF-stimulatory viral protein, nsp1β. Surprisingly, we find that PRF efficiency at the canonical ORF1ab frameshift site also increases over time, in contradiction of the common assumption that RNA structure-directed frameshift sites operate at a fixed efficiency. This has potential implications for the numerous other viruses with canonical PRF sites. Furthermore, we discovered several highly translated additional viral ORFs, the translation of which may be facilitated by multiple novel viral transcripts. For example, we found a highly expressed 125-codon ORF overlapping nsp12, which is likely translated from novel subgenomic RNA transcripts that overlap the 3' end of ORF1b. Similar transcripts were discovered for both PRRSV-1 and PRRSV-2, suggesting a potential conserved mechanism for temporally regulating expression of the 3'-proximal region of ORF1b. We also identified a highly translated, short upstream ORF in the 5' UTR, the presence of which is highly conserved amongst PRRSV-2 isolates. These findings reveal hidden complexity in the gene expression programmes of these important nidoviruses.
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Affiliation(s)
- Georgia M Cook
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Katherine Brown
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Pengcheng Shang
- Department of Diagnostic Medicine and Pathobiology, Kansas State UniversityManhattanUnited States
| | - Yanhua Li
- Department of Diagnostic Medicine and Pathobiology, Kansas State UniversityManhattanUnited States
| | - Lior Soday
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Adam M Dinan
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | | | | | - Ying Fang
- Department of Diagnostic Medicine and Pathobiology, Kansas State UniversityManhattanUnited States
| | - Andrew E Firth
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Ian Brierley
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
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7
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Li J, Wang D, Fang P, Pang Y, Zhou Y, Fang L, Xiao S. DEAD-Box RNA Helicase 21 (DDX21) Positively Regulates the Replication of Porcine Reproductive and Respiratory Syndrome Virus via Multiple Mechanisms. Viruses 2022; 14:v14030467. [PMID: 35336874 PMCID: PMC8949431 DOI: 10.3390/v14030467] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022] Open
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) remains a persistent hazard in the global pig industry. DEAD (Glu-Asp-Ala-Glu) box helicase 21 (DDX21) is a member of the DDX family. In addition to its function of regulating cellular RNA metabolism, DDX21 also regulates innate immunity and is involved in the replication cycle of some viruses. However, the relationship between DDX21 and PRRSV has not yet been explored. Here, we found that a DDX21 overexpression promoted PRRSV replication, whereas knockdown of DDX21 reduced PRRSV proliferation. Mechanistically, DDX21 promoted PRRSV replication independently of its ATPase, RNA helicase, and foldase activities. Furthermore, overexpression of DDX21 stabilized the expressions of PRRSV nsp1α, nsp1β, and nucleocapsid proteins, three known antagonists of interferon β (IFN-β). Knockdown of DDX21 activated the IFN-β signaling pathway in PRRSV-infected cells, suggesting that the effect of DDX21 on PRRSV-encoded IFN-β antagonists may be a driving factor for its contribution to viral proliferation. We also found that PRRSV infection enhanced DDX21 expression and promoted its nucleus-to-cytoplasm translocation. Screening PRRSV-encoded proteins showed that nsp1β interacted with the C-terminus of DDX21 and enhanced the expression of DDX21. Taken together, these findings reveal that DDX21 plays an important role in regulating PRRSV proliferation through multiple mechanisms.
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Affiliation(s)
- Jia Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Puxian Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Yu Pang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Yanrong Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (J.L.); (D.W.); (P.F.); (Y.P.); (Y.Z.); (L.F.)
- The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Correspondence:
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8
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Duan Z, Yuan C, Han Y, Zhou L, Zhao J, Ruan Y, Chen J, Ni M, Ji X. TMT-based quantitative proteomics analysis reveals the attenuated replication mechanism of Newcastle disease virus caused by nuclear localization signal mutation in viral matrix protein. Virulence 2021; 11:607-635. [PMID: 32420802 PMCID: PMC7549962 DOI: 10.1080/21505594.2020.1770482] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Nuclear localization of cytoplasmic RNA virus proteins mediated by intrinsic nuclear localization signal (NLS) plays essential roles in successful virus replication. We previously reported that NLS mutation in the matrix (M) protein obviously attenuates the replication and pathogenicity of Newcastle disease virus (NDV), but the attenuated replication mechanism remains unclear. In this study, we showed that M/NLS mutation not only disrupted M's nucleocytoplasmic trafficking characteristic but also impaired viral RNA synthesis and transcription. Using TMT-based quantitative proteomics analysis of BSR-T7/5 cells infected with the parental NDV rSS1GFP and the mutant NDV rSS1GFP-M/NLSm harboring M/NLS mutation, we found that rSS1GFP infection stimulated much greater quantities and more expression changes of differentially expressed proteins involved in host cell transcription, ribosomal structure, posttranslational modification, and intracellular trafficking than rSS1GFP-M/NLSm infection. Further in-depth analysis revealed that the dominant nuclear accumulation of M protein inhibited host cell transcription, RNA processing and modification, protein synthesis, posttranscriptional modification and transport; and this kind of inhibition could be weakened when most of M protein was confined outside the nucleus. More importantly, we found that the function of M protein in the cytoplasm effected the inhibition of TIFA expression in a dose-dependent manner, and promoted NDV replication by down-regulating TIFA/TRAF6/NF-κB-mediated production of cytokines. It was the first report about the involvement of M protein in NDV immune evasion. Taken together, our findings demonstrate that NDV replication is closely related to the nucleocytoplasmic trafficking of M protein, which accelerates our understanding of the molecular functions of NDV M protein.
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Affiliation(s)
- Zhiqiang Duan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Chao Yuan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Yifan Han
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Lei Zhou
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Jiafu Zhao
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Yong Ruan
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Jiaqi Chen
- College of Animal Science, Guizhou University , Guiyang, China
| | - Mengmeng Ni
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University , Guiyang, China.,College of Animal Science, Guizhou University , Guiyang, China
| | - Xinqin Ji
- College of Animal Science, Guizhou University , Guiyang, China
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9
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Wall GV, Wright IM, Barnardo C, Erasmus BJ, van Staden V, Potgieter AC. African horse sickness virus NS4 protein is an important virulence factor and interferes with JAK-STAT signaling during viral infection. Virus Res 2021; 298:198407. [PMID: 33812899 DOI: 10.1016/j.virusres.2021.198407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 12/24/2022]
Abstract
African horse sickness virus (AHSV) non-structural protein NS4 is a nucleocytoplasmic protein that is expressed in the heart, lung, and spleen of infected horses, binds dsDNA, and colocalizes with promyelocytic leukemia nuclear bodies (PML-NBs). The aim of this study was to investigate the role of AHSV NS4 in viral replication, virulence and the host immune response. Using a reverse genetics-derived virulent strain of AHSV-5 and NS4 deletion mutants, we showed that knockdown of NS4 expression has no impact in cell culture, but results in virus attenuation in infected horses. RNA sequencing (RNA-seq) was used to investigate the transcriptional response in these horses, to see how the lack of NS4 mediates the transition of the virus from virulent to attenuated. The presence of NS4 was shown to result in a 24 hour (h) delay in the transcriptional activation of several immune system processes compared to when the protein was absent. Included in these processes were the RIG-I-like, Toll-like receptor, and JAK-STAT signaling pathways, which are key pathways involved in innate immunity and the antiviral response. Thus, it was shown that AHSV NS4 suppresses the host innate immune transcriptional response in the early stages of the infection cycle. We investigated whether AHSV NS4 affects the innate immune response by impacting the JAK-STAT signaling pathway specifically. Using confocal laser scanning microscopy (CLSM) we showed that AHSV NS4 disrupts JAK-STAT signaling by interfering with the phosphorylation and/or translocation of STAT1 and pSTAT1 into the nucleus. Overall, these results showed that AHSV NS4 is a key virulence factor in horses and allows AHSV to overcome host antiviral responses in order to promote viral replication and spread.
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Affiliation(s)
- Gayle V Wall
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - Isabella M Wright
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Carin Barnardo
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Baltus J Erasmus
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa
| | - Vida van Staden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, 0002, South Africa
| | - A Christiaan Potgieter
- Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa; Department of Biochemistry, Focus Area for Human Metabolomics, North-West University, Potchefstroom, South Africa.
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10
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Sun H, Huang Y, Mei S, Xu F, Liu X, Zhao F, Yin L, Zhang D, Wei L, Wu C, Ma S, Wang J, Cen S, Liang C, Hu S, Guo F. A Nuclear Export Signal Is Required for cGAS to Sense Cytosolic DNA. Cell Rep 2021; 34:108586. [PMID: 33406424 DOI: 10.1016/j.celrep.2020.108586] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/02/2020] [Accepted: 12/10/2020] [Indexed: 02/08/2023] Open
Abstract
The cyclic GMP-AMP (cGAMP) synthase (cGAS) is a key DNA sensor that initiates STING-dependent signaling to produce type I interferons through synthesizing the secondary messenger 2'3'-cGAMP. In this study, we confirm previous studies showing that cGAS is located both in the cytoplasm and in the nucleus. Nuclear accumulation is observed when leptomycin B is used to block the exportin, CRM1 protein. As a result, leptomycin B impairs the production of interferons in response to DNA stimulation. We further identify a functional nuclear export signal (NES) in cGAS, 169LEKLKL174. Mutating this NES leads to the sequestration of cGAS within the nucleus and the loss of interferon response to cytosolic DNA treatment, and it further determines the key amino acid to L172. Collectively, our data demonstrate that the cytosolic DNA-sensing function of cGAS depends on its presence within the cytoplasm, which is warranted by a functional NES.
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Affiliation(s)
- Hong Sun
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Yu Huang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Shan Mei
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Fengwen Xu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Xiaoman Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Fei Zhao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Lijuan Yin
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Di Zhang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Liang Wei
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Chao Wu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Shichao Ma
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Jianwei Wang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, PRC
| | - Chen Liang
- McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal H3T 1E2, Canada
| | - Siqi Hu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC.
| | - Fei Guo
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, and Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, PRC.
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11
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Molecular and Cellular Mechanisms for PRRSV Pathogenesis and Host Response to Infection. Virus Res 2020; 286:197980. [PMID: 32311386 PMCID: PMC7165118 DOI: 10.1016/j.virusres.2020.197980] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/13/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022]
Abstract
PRRSV has evolved to arm with various strategies to modify host antiviral response. Viral modulation of homeostatic cellular processes provides favorable conditions for PRRSV survival during infection. PRRSV modulation of cellular processes includes pathways for interferons, apoptosis, microRNAs, cytokines, autophagy, and viral genome recombination.
Porcine reproductive and respiratory syndrome virus (PRRSV) has caused tremendous amounts of economic losses to the swine industry for more than three decades, but its control is still unsatisfactory. A significant amount of information is available for host cell-virus interactions during infection, and it is evident that PRRSV has evolved to equip various strategies to disrupt the host antiviral system and provide favorable conditions for survival. The current study reviews viral strategies for modulations of cellular processes including innate immunity, apoptosis, microRNAs, inflammatory cytokines, and other cellular pathways.
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12
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Xu J, Zhang L, Xu Y, Zhang H, Gao J, Wang Q, Tian Z, Xuan L, Chen H, Wang Y. PP2A Facilitates Porcine Reproductive and Respiratory Syndrome Virus Replication by Deactivating irf3 and Limiting Type I Interferon Production. Viruses 2019; 11:v11100948. [PMID: 31618847 PMCID: PMC6832233 DOI: 10.3390/v11100948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/11/2019] [Accepted: 10/11/2019] [Indexed: 12/12/2022] Open
Abstract
Protein phosphatase 2A (PP2A), a major serine/threonine phosphatase in mammalian cells, is known to regulate the kinase-driven intracellular signaling pathways. Emerging evidences have shown that the PP2A phosphatase functions as a bona-fide therapeutic target for anticancer therapy, but it is unclear whether PP2A affects a porcine reproductive and respiratory syndrome virus infection. In the present study, we demonstrated for the first time that inhibition of PP2A activity by either inhibitor or small interfering RNA duplexes in target cells significantly reduced their susceptibility to porcine reproductive and respiratory syndrome virus (PRRSV) infection. Further analysis revealed that inhibition of PP2A function resulted in augmented production of type I interferon (IFN). The mechanism is that inhibition of PP2A activity enhances the levels of phosphorylated interferon regulatory factor 3, which activates the transcription of IFN-stimulated genes. Moreover, inhibition of PP2A activity mainly blocked PRRSV replication in the early stage of viral life cycle, after virus entry but before virus release. Using type I IFN receptor 2 specific siRNA in combination with PP2A inhibitor, we confirmed that the effect of PP2A on viral replication within target cells was an interferon-dependent manner. Taken together, these findings demonstrate that PP2A serves as a negative regulator of host cells antiviral responses and provides a novel therapeutic target for virus infection.
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Affiliation(s)
- Jiayu Xu
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Lu Zhang
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Yunfei Xu
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - He Zhang
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Junxin Gao
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Qian Wang
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhijun Tian
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Lv Xuan
- Department of public health policy, University of California, Irvine, CA 92697, USA
| | - Hongyan Chen
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
| | - Yue Wang
- State Key Laboratory of Veterinary Biotechnology, Heilongjiang Provincial Key Laboratory of Laboratory Animal and Comparative Medicine, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China.
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13
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Ke H, Han M, Kim J, Gustin KE, Yoo D. Porcine Reproductive and Respiratory Syndrome Virus Nonstructural Protein 1 Beta Interacts with Nucleoporin 62 To Promote Viral Replication and Immune Evasion. J Virol 2019; 93:e00469-19. [PMID: 31043527 PMCID: PMC6600190 DOI: 10.1128/jvi.00469-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/23/2019] [Indexed: 12/18/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) blocks host mRNA nuclear export to the cytoplasm, and nonstructural protein 1 beta (nsp1β) of PRRSV has been identified as the protein that disintegrates the nuclear pore complex. In the present study, the molecular basis for the inhibition of host mRNA nuclear export was investigated. Nucleoporin 62 (Nup62) was found to bind to nsp1β, and the region representing the C-terminal residues 328 to 522 of Nup62 was determined to be the binding domain for nsp1β. The nsp1β L126A mutant in the SAP domain did not bind to Nup62, and in L126A-expressing cells, host mRNA nuclear export occurred normally. The vL126A mutant PRRSV generated by reverse genetics replicated at a lower rate, and the titer was lower than for wild-type virus. In nsp1β-overexpressing cells or small interfering RNA (siRNA)-mediated Nup62 knockdown cells, viral protein synthesis increased. Notably, the production of type I interferons (IFN-α/β), IFN-stimulated genes (PKR, OAS, Mx1, and ISG15 genes), IFN-induced proteins with tetratricopeptide repeats (IFITs) 1 and 2, and IFN regulatory factor 3 decreased in these cells. As a consequence, the growth of vL126A mutant PRRSV was rescued to the level of wild-type PRRSV. These findings are attributed to nuclear pore complex (NPC) disintegration by nsp1β, resulting in increased viral protein production and decreased host protein production, including antiviral proteins in the cytoplasm. Our study reveals a new strategy of PRRSV for immune evasion and enhanced replication during infection.IMPORTANCE Porcine reproductive and respiratory syndrome virus (PRRSV) causes PRRS and is known to effectively suppress host innate immunity. The PRRSV nsp1β protein blocks host mRNA nuclear export, which has been shown to be one of the viral mechanisms for inhibition of antiviral protein production. nsp1β binds to the cellular protein nucleoporin 62 (Nup62), and as a consequence, the nuclear pore complex (NPC) is disintegrated and the nucleocytoplasmic trafficking of host mRNAs and host proteins is blocked. We show the dual benefits of Nup62 and nsp1β binding for PRRSV replication: the inhibition of host antiviral protein expression and the exclusive use of host translation machinery by the virus. Our study unveils a novel strategy of PRRSV for immune evasion and enhanced replication during infection.
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Affiliation(s)
- Hanzhong Ke
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Mingyuan Han
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, USA
| | - Jineui Kim
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kurt E Gustin
- Department of Basic Medical Sciences, College of Medicine-Phoenix, The University of Arizona, Phoenix, Arizona, USA
| | - Dongwan Yoo
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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14
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Chen J, Wang D, Sun Z, Gao L, Zhu X, Guo J, Xu S, Fang L, Li K, Xiao S. Arterivirus nsp4 Antagonizes Interferon Beta Production by Proteolytically Cleaving NEMO at Multiple Sites. J Virol 2019; 93:e00385-19. [PMID: 30944180 PMCID: PMC6613749 DOI: 10.1128/jvi.00385-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/30/2019] [Indexed: 12/24/2022] Open
Abstract
Equine arteritis virus (EAV) and porcine reproductive and respiratory syndrome virus (PRRSV) represent two members of the family Arteriviridae and pose major threats for the horse- and swine-breeding industries worldwide. A previous study suggested that PRRSV nsp4, a 3C-like protease, antagonizes interferon beta (IFN-β) production by cleaving the NF-κB essential modulator (NEMO) at a single site, glutamate 349 (E349). Here, we demonstrated that EAV nsp4 also inhibited virus-induced IFN-β production by targeting NEMO for proteolytic cleavage and that the scission occurred at four sites: E166, E171, glutamine 205 (Q205), and E349. Additionally, we found that, besides the previously reported cleavage site E349 in NEMO, scission by PRRSV nsp4 took place at two additional sites, E166 and E171. These results imply that while cleaving NEMO is a common strategy utilized by EAV and PRRSV nsp4 to antagonize IFN induction, EAV nsp4 adopts a more complex substrate recognition mechanism to target NEMO. By analyzing the abilities of the eight different NEMO fragments resulting from EAV or PRRSV nsp4 scission to induce IFN-β production, we serendipitously found that a NEMO fragment (residues 1 to 349) could activate IFN-β transcription more robustly than full-length NEMO, whereas all other NEMO cleavage products were abrogated for the IFN-β-inducing capacity. Thus, NEMO cleavage at E349 alone may not be sufficient to completely inactivate the IFN response via this signaling adaptor. Altogether, our findings suggest that EAV and PRRSV nsp4 cleave NEMO at multiple sites and that this strategy is critical for disarming the innate immune response for viral survival.IMPORTANCE The arterivirus nsp4-encoded 3C-like protease (3CLpro) plays an important role in virus replication and immune evasion, making it an attractive target for antiviral therapeutics. Previous work suggested that PRRSV nsp4 suppresses type I IFN production by cleaving NEMO at a single site. In contrast, the present study demonstrates that both EAV and PRRSV nsp4 cleave NEMO at multiple sites and that this strategy is essential for disruption of type I IFN production. Moreover, we reveal that EAV nsp4 also cleaves NEMO at glutamine 205 (Q205), which is not targeted by PRRSV nsp4. Notably, targeting a glutamine in NEMO for cleavage has been observed only with picornavirus 3C proteases (3Cpro) and coronavirus 3CLpro In aggregate, our work expands knowledge of the innate immune evasion mechanisms associated with NEMO cleavage by arterivirus nsp4 and describes a novel substrate recognition characteristic of EAV nsp4.
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Affiliation(s)
- Jiyao Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Zheng Sun
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Li Gao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Xinyu Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Jiahui Guo
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shangen Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Kui Li
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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15
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ZAP, a CCCH-Type Zinc Finger Protein, Inhibits Porcine Reproductive and Respiratory Syndrome Virus Replication and Interacts with Viral Nsp9. J Virol 2019; 93:JVI.00001-19. [PMID: 30867303 DOI: 10.1128/jvi.00001-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 03/04/2019] [Indexed: 01/27/2023] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens affecting many swine-producing regions. Current vaccination strategies and antiviral drugs provide only limited protection. PRRSV infection can cleave mitochondrial antiviral signaling protein (MAVS) and inhibit the induction of type I interferon. The antiviral effector molecules that are involved in host protective responses to PRRSV infection are not fully understood. Here, by using transcriptome sequencing, we found that a zinc finger antiviral protein, ZAP, is upregulated in MAVS-transfected Marc-145 cells and that ZAP suppresses PRRSV infection at the early stage of replication. We also found that the viral protein Nsp9, an RNA-dependent RNA polymerase (RdRp), interacts with ZAP. The interacting locations were mapped to the zinc finger domain of ZAP and N-terminal amino acids 150 to 160 of Nsp9. These findings suggest that ZAP is an effective antiviral factor for suppressing PRRSV infection, and they shed light on virus-host interaction.IMPORTANCE PRRSV continues to adversely impact the global swine industry. It is important to understand the various antiviral factors against PRRSV infection. Here, a zinc finger protein, termed ZAP, was screened from MAVS-induced antiviral genes by transcriptome sequencing, and it was found to remarkably suppress PRRSV replication and interact with PRRSV Nsp9. The zinc finger domain of ZAP and amino acids 150 to 160 of Nsp9 are responsible for the interaction. These findings expand the antiviral spectrum of ZAP and provide a better understanding of ZAP antiviral mechanisms, as well as virus-host interactions.
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16
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Shi P, Su Y, Li R, Zhang L, Chen C, Zhang L, Faaberg K, Huang J. Dual Regulation of Host TRAIP Post-translation and Nuclear/Plasma Distribution by Porcine Reproductive and Respiratory Syndrome Virus Non-structural Protein 1α Promotes Viral Proliferation. Front Immunol 2018; 9:3023. [PMID: 30619364 PMCID: PMC6305329 DOI: 10.3389/fimmu.2018.03023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/06/2018] [Indexed: 12/11/2022] Open
Abstract
In this study, we show that porcine reproductive and respiratory syndrome virus (PRRSV) non-structural protein 1α (nsp1α) facilitates PRRSV escape from innate immune by modulating nuclear to cytoplasmic translocation and distribution ratio of TRAIP to promote virus proliferation. Mechanistically, TRAIP interacts with PRRSV nsp1α via its K205 site, while NSP1α decreases the SUMOylation and K48 ubiquitination independent of the TRAIP interaction K205 site. Modulation of the dual modification of TRAIP by PRRSV nsp1α results in over-enrichment of TRAIP in the cytoplasm. Enrichment of nsp1α-induced cytoplasmic TRAIP in turn leads to excessive K48 ubiquitination and degradation of serine/threonine-protein kinase (TBK1), thereby antagonizing TBK1-IRF3-IFN signaling. This study proposes a novel mechanism by which PRRSV utilizes host proteins to regulate innate immunity. Findings from this study provides novel perspective to advance our understanding in the pathogenesis of PRRSV.
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Affiliation(s)
- Peidian Shi
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Yanxin Su
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Ruiqiao Li
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Lei Zhang
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Chen Chen
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Lilin Zhang
- School of Life Sciences, Tianjin University, Tianjin, China
| | - Kay Faaberg
- Agricultural Research Service, USDA, National Animal Disease Center, Ames, IA, United States
| | - Jinhai Huang
- School of Life Sciences, Tianjin University, Tianjin, China
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17
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Chen X, Bai J, Liu X, Song Z, Zhang Q, Wang X, Jiang P. Nsp1α of Porcine Reproductive and Respiratory Syndrome Virus Strain BB0907 Impairs the Function of Monocyte-Derived Dendritic Cells via the Release of Soluble CD83. J Virol 2018; 92:e00366-18. [PMID: 29793955 PMCID: PMC6052304 DOI: 10.1128/jvi.00366-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/08/2018] [Indexed: 12/21/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV), a virulent pathogen of swine, suppresses the innate immune response and induces persistent infection. One mechanism used by viruses to evade the immune system is to cripple the antigen-processing machinery in monocyte-derived dendritic cells (MoDCs). In this study, we show that MoDCs infected by PRRSV express lower levels of the major histocompatibility complex (MHC)-peptide complex proteins TAP1 and ERp57 and are impaired in their ability to stimulate T cell proliferation and increase their production of CD83. Neutralization of sCD83 removes the inhibitory effects of PRRSV on MoDCs. When MoDCs are incubated with exogenously added sCD83 protein, TAP1 and ERp57 expression decreases and T lymphocyte activation is impaired. PRRSV nonstructural protein 1α (Nsp1α) enhances CD83 promoter activity. Mutations in the ZF domain of Nsp1α abolish its ability to activate the CD83 promoter. We generated recombinant PRRSVs with mutations in Nsp1α and the corresponding repaired PRRSVs. Viruses with Nsp1α mutations did not decrease levels of TAP1 and ERp57, impair the ability of MoDCs to stimulate T cell proliferation, or increase levels of sCD83. We show that the ZF domain of Nsp1α stimulates the secretion of CD83, which in turn inhibits MoDC function. Our study provides new insights into the mechanisms of immune suppression by PRRSV.IMPORTANCE PRRSV has a severe impact on the swine industry throughout the world. Understanding the mechanisms by which PRRSV infection suppresses the immune system is essential for a robust and sustainable swine industry. Here, we demonstrated that PRRSV infection manipulates MoDCs by interfering with their ability to produce proteins in the MHC-peptide complex. The virus also impairs the ability of MoDCs to stimulate cell proliferation, due in large part to the enhanced release of soluble CD83 from PRRSV-infected MoDCs. The viral nonstructural protein 1 (Nsp1) is responsible for upregulating CD83 promoter activity. Amino acids in the ZF domain of Nsp1α (L5-2A, rG45A, G48A, and L61-6A) are essential for CD83 promoter activation. Viruses with mutations at these sites no longer inhibit MoDC-mediated T cell proliferation. These findings provide novel insights into the mechanism by which the adaptive immune response is suppressed during PRRSV infection.
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Affiliation(s)
- Xi Chen
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Juan Bai
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xuewei Liu
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zhongbao Song
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Qiaoya Zhang
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xianwei Wang
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Ping Jiang
- Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Jiangsu Coinnovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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18
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Ke H, Han M, Zhang Q, Rowland R, Kerrigan M, Yoo D. Type I interferon suppression-negative and host mRNA nuclear retention-negative mutation in nsp1β confers attenuation of porcine reproductive and respiratory syndrome virus in pigs. Virology 2018; 517:177-187. [PMID: 29402432 DOI: 10.1016/j.virol.2018.01.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/17/2018] [Accepted: 01/21/2018] [Indexed: 12/20/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has the ability to suppress the type I interferons (IFNs-α/β) induction to facilitate its survival during infection, and the nsp1 protein of PRRSV has been identified as the potent IFN antagonist. The nsp1β subunit of nsp1 has also been shown to block the host mRNA nuclear export as one of the mechanisms to suppress host antiviral protein production. The SAP motif in nsp1β is the functional motif for both IFN suppression and host mRNA nuclear retention, and using infectious clones, two mutant viruses vL126A and vL135A have been generated. These mutants retain the infectivity, but the phenotype is negative for both IFN suppression and host mRNA nuclear retention due to the loss of the SAP motif. To examine the pathogenic role of IFN suppression in pigs, 40 piglets were allotted to four groups and each group was intramuscularly infected with vL126A, vL135A, wild-type (WT) PRRSV, and placebo. Pigs infected with vL126A or vL135A exhibited mild clinical signs with low viral titers and short duration of viremia. The levels of PRRSV-specific antibody remained comparable in all infected groups but the neutralizing antibody titers were high in vL126A-infected or vL135A-infected pigs. The IFN-α concentration was also high in pigs infected with the SAP mutants. Reversion to WT sequence was observed in the SAP motif in some animals, and the revertants regained the function to suppress IFN production and host mRNA nuclear export, indicating strong selection pressure in the SAP motif of nsp1β. Together, our data demonstrate that the IFN antagonism and host mRNA nuclear retention mediated by nsp1β contributes to viral virulence, and loss of these functions confers PRRSV attenuation.
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Affiliation(s)
- Hanzhong Ke
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Mingyuan Han
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA
| | - Qingzhan Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Raymond Rowland
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Maureen Kerrigan
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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19
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Jing H, Zhou Y, Fang L, Ding Z, Wang D, Ke W, Chen H, Xiao S. DExD/H-Box Helicase 36 Signaling via Myeloid Differentiation Primary Response Gene 88 Contributes to NF-κB Activation to Type 2 Porcine Reproductive and Respiratory Syndrome Virus Infection. Front Immunol 2017; 8:1365. [PMID: 29123520 PMCID: PMC5662876 DOI: 10.3389/fimmu.2017.01365] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/05/2017] [Indexed: 02/02/2023] Open
Abstract
DExD/H-box helicase 36 (DHX36) is known to be an ATP-dependent RNA helicase that unwinds the guanine-quadruplexes DNA or RNA, but emerging data suggest that it also functions as pattern recognition receptor in innate immunity. Porcine reproductive and respiratory syndrome virus (PRRSV) is an Arterivirus that has been devastating the swine industry worldwide. Interstitial pneumonia is considered to be one of the most obvious clinical signs of PRRSV infection, suggesting that the inflammatory response plays an important role in PRRSV pathogenesis. However, whether DHX36 is involved in PRRSV-induced inflammatory cytokine expression remains unclear. In this study, we found that PRRSV infection increased the expression of DHX36. Knockdown of DHX36 and its adaptor myeloid differentiation primary response gene 88 (MyD88) by small-interfering RNA in MARC-145 cells significantly reduced NF-κB activation and pro-inflammatory cytokine expression after PRRSV infection. Further investigation revealed that PRRSV nucleocapsid protein interacted with the N-terminal quadruplex binding domain of DHX36, which in turn augmented nucleocapsid protein-induced NF-κB activation. Taken together, our results suggest that DHX36-MyD88 has a relevant role in the recognition of PRRSV nucleocapsid protein and in the subsequent activation of pro-inflammatory NF-κB pathway.
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Affiliation(s)
- Huiyuan Jing
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Yanrong Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Zhen Ding
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Wenting Ke
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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Identification of a linear B-cell epitope on non-structural protein 12 of porcine reproductive and respiratory syndrome virus, using a monoclonal antibody. Arch Virol 2017; 162:2239-2246. [PMID: 28365807 DOI: 10.1007/s00705-017-3355-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 03/20/2017] [Indexed: 10/19/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has caused tremendous economic losses and continues to be a serious problem to the swine industry worldwide. The structure and function of PRRSV nonstructural protein 12 (NSP12) is still unknown. In this study, we produced a monoclonal antibody, named as 1E5, against the NSP12 protein of HP (highly pathogenic) -PRRSV strain HuN4. A series of partially overlapping recombinant NSP12 truncations and synthesized peptides were used to define the epitope recognized by 1E5. We found that 130KANATSMRFH139 is the minimal linear epitope and that it is highly conserved among some HP-PRRSV isolates of type 2 PRRSV, but not the classical isolates of type 2 PRRSV or the isolates of type 1 PRRSV. Therefore, 1E5 can be used to establish a valuable tool to distinguish infections with HP-PRRSV isolates of type 2 PRRSV from the classical isolates of type 2 PRRSV and type 1 PRRSV.
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The viral innate immune antagonism and an alternative vaccine design for PRRS virus. Vet Microbiol 2017; 209:75-89. [PMID: 28341332 PMCID: PMC7111430 DOI: 10.1016/j.vetmic.2017.03.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 02/06/2023]
Abstract
PRRS virus has evolved to suppress the antiviral innate immunity during infection. Type I interferons are potent antiviral cytokines and function to stimulate the adaptive immune responses. Six viral proteins have been identified as interferon antagonists and characterized for their molecular actions. Interferon antagonism-negative viruses are attenuated and have been proven induce protective immunity. Interferon suppression-negative PRRS virus may serve as an alternative vaccine for PRRS.
Porcine reproductive and respiratory syndrome (PRRS) remains one of the most economically significant diseases in the swine industry worldwide. The current vaccines are less satisfactory to confer protections from heterologous infections and long-term persistence, and the need for better vaccines are urgent. The immunological hallmarks in PRRSV-infected pigs include the unusually poor production of type I interferons (IFNs-α/β) and the aberrant and delayed adaptive immune responses, indicating that PRRSV has the ability to suppress both innate and adaptive immune responses in the host. Type I IFNs are the potent antiviral cytokines and recent studies reveal their pleiotropic functions in the priming of expansion and maturation of adaptive immunity. Thus, IFN antagonism-negative PRRSV is hypothesized to be attenuated and to build effective and broad- spectrum innate and adaptive immune responses in pigs. Such vaccines are promising alternatives to traditional vaccines for PRRSV.
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