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Durie IA, Dzimianski JV, Daczkowski CM, McGuire J, Faaberg K, Pegan SD. Structural insights into the interaction of papain-like protease 2 from the alphacoronavirus porcine epidemic diarrhea virus and ubiquitin. Acta Crystallogr D Struct Biol 2021; 77:943-953. [PMID: 34196620 PMCID: PMC8251346 DOI: 10.1107/s205979832100509x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/13/2021] [Indexed: 01/02/2023] Open
Abstract
Porcine epidemic diarrhea is a devastating porcine disease that is caused by the alphacoronavirus porcine epidemic diarrhea virus (PEDV). Like other members of the Coronaviridae family, PEDV encodes a multifunctional papain-like protease 2 (PLP2) that has the ability to process the coronavirus viral polyprotein to aid in RNA replication and antagonize the host innate immune response through cleavage of the regulatory proteins ubiquitin (Ub) and/or interferon-stimulated gene product 15 (ISG15) (deubiquitination and deISGylation, respectively). Because Betacoronavirus PLPs have been well characterized, it was sought to determine how PLP2 from the alphacoronavirus PEDV differentiates itself from its related counterparts. PEDV PLP2 was first biochemically characterized, and a 3.1 Å resolution crystal structure of PEDV PLP2 bound to Ub was then solved, providing insight into how Alphacoronavirus PLPs bind to their preferred substrate, Ub. It was found that PEDV PLP2 is a deubiquitinase and readily processes a variety of di-Ub linkages, in comparison with its Betacoronavirus counterparts, which have a narrower range of di-Ub activity but process both Ub and ISG15.
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Affiliation(s)
- Ian A. Durie
- Pharmaceutical and Biomedical Sciences, University of Georgia, 240 West Green Street, Athens, GA 30602, USA
| | - John V. Dzimianski
- Pharmaceutical and Biomedical Sciences, University of Georgia, 240 West Green Street, Athens, GA 30602, USA
| | - Courtney M. Daczkowski
- Pharmaceutical and Biomedical Sciences, University of Georgia, 240 West Green Street, Athens, GA 30602, USA
| | - Jack McGuire
- Pharmaceutical and Biomedical Sciences, University of Georgia, 240 West Green Street, Athens, GA 30602, USA
| | - Kay Faaberg
- Virus and Prion Research Unit, USDA–ARS–National Animal Disease Center, Ames, IA 50010, USA
| | - Scott D. Pegan
- Pharmaceutical and Biomedical Sciences, University of Georgia, 240 West Green Street, Athens, GA 30602, USA
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Park J, Choi S, Jeon JH, Lee KW, Lee C. Novel lineage 1 recombinants of porcine reproductive and respiratory syndrome virus isolated from vaccinated herds: genome sequences and cytokine production profiles. Arch Virol 2020; 165:2259-2277. [PMID: 32699981 DOI: 10.1007/s00705-020-04743-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/18/2020] [Indexed: 01/19/2023]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a widely disseminated, macrophage-tropic arterivirus that exhibits profound genetic and pathogenic heterogeneity. The present study was conducted to determine the complete genome sequences of two novel Korean lineage 1 PRRSV-2 strains, KNU-1901 and KNU-1902, which were isolated from vaccinated pig farms experiencing unusually high morbidity and mortality. Both isolates contained notable discontinuous 423-nucleotide deletions (DELs) within the genes encoding nonstructural protein 2 (nsp2) and GP3 when compared with the prototype strain VR-2332. In particular, the nsp2 DEL viruses had unique quadripartite discontinuous DEL signatures (111-1-19-9) in nsp2; this is an expanded version of the tripartite 111-1-19 DEL previously identified in virulent lineage 1 PRRSV-2 strains. Phylogenetic analysis revealed that both novel nsp2 DEL viruses belong to the Korean clade (KOR C) of lineage 1 isolates based on ORF5 but cluster with lineage KOR A strains based on the nsp2 or complete genome sequence. Recombination detection analysis suggested that both novel isolates are recombinants and may have evolved via natural inter-lineage recombination between circulating KOR A and KOR C strains. Interestingly, compared with the prototype VR-2332 virus, the novel nsp2 DEL variants were less efficient at promoting the expression of immune response genes in porcine alveolar macrophage culture. Taken together, we conclude that KNU-1901 and KNU-1902 are recently evolved recombinant variants of the virulent lineage 1 family that caused the regional severe PRRS outbreaks.
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Affiliation(s)
- Jonghyun Park
- Animal Virology Laboratory, School of Life Sciences, College of Natural Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Subin Choi
- Animal Virology Laboratory, School of Life Sciences, College of Natural Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Ji Hyun Jeon
- Animal Virology Laboratory, School of Life Sciences, College of Natural Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | | | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, College of Natural Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea.
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Bester SM, Daczkowski CM, Faaberg KS, Pegan SD. Insights into the Porcine Reproductive and Respiratory Syndrome Virus Viral Ovarian Tumor Domain Protease Specificity for Ubiquitin and Interferon Stimulated Gene Product 15. ACS Infect Dis 2018; 4:1316-1326. [PMID: 29856201 DOI: 10.1021/acsinfecdis.8b00068] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a widespread economically devastating disease caused by PRRS virus (PRRSV). First recognized in the late 1980s, PRRSV is known to undergo somatic mutations and high frequency viral recombination, which leads to many diverse viral strains. This includes differences within viral virulence factors, such as the viral ovarian tumor domain (vOTU) protease, also referred to as the papain-like protease 2. These proteases down-regulate innate immunity by deubiquitinating proteins targeted by the cell for further processing and potentially also acting against interferon-stimulated genes (ISGs). Recently, vOTUs from vaccine derivative Ingelvac PRRS modified live virus (MLV) and the highly pathogenic PRRSV strain JXwn06 were biochemically characterized, revealing a marked difference in activity toward K63 linked polyubiquitin chains and a limited preference for interferon-stimulated gene product 15 (ISG15) substrates. To extend our research, the vOTUs from NADC31 (low virulence) and SDSU73 (moderately virulent) were biochemically characterized using a myriad of ubiquitin and ISG15 related assays. The K63 polyubiquitin cleavage activity profiles of these vOTUs were found to track with the established pathogenesis of MLV, NADC31, SDSU73, and JXwn06 strains. Fascinatingly, NADC31 demonstrated significantly enhanced activity toward ISG15 substrates compared to its counterparts. Utilizing this information and strain-strain differences within the vOTU encoding region, sites were identified that can modulate K63 polyubiquitin and ISG15 cleavage activities. This information represents the basis for new tools to probe the role of vOTUs in the context of PRRSV pathogenesis.
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Affiliation(s)
- Stephanie M. Bester
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602, United States
| | - Courtney M. Daczkowski
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602, United States
| | - Kay S. Faaberg
- Virus and Prion Research Unit, USDA-ARS-National Animal Disease Center, Ames, Iowa 50010, United States
| | - Scott D. Pegan
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia 30602, United States
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Lee SC, Lee S, Yoo GW, Choi HW, Noh YH, Park CE, Shin JH, Yoon IJ, Kang SY, Lee C. Phenotypic and genotypic analyses of an attenuated porcine reproductive and respiratory syndrome virus strain after serial passages in cultured porcine alveolar macrophages. J Vet Sci 2018; 19:358-367. [PMID: 29486535 PMCID: PMC5974517 DOI: 10.4142/jvs.2018.19.3.358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/24/2018] [Accepted: 01/30/2018] [Indexed: 12/02/2022] Open
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine viral pathogen that causes major economic losses worldwide. We previously reported an over-attenuated phenotype of cell-adapted PRRSV strain CA-2-P100 in vivo. In the present study, CA-2-P100 was serially propagated in cultured porcine alveolar macrophage (PAM) cells for up to 20 passages to obtain the derivative strain CA-2-MP120. Animal inoculation studies revealed that both CA-2-P100 and CA-2-MP120 had decreased virulence, eliciting weight gains, body temperatures, and histopathologic lesions similar to those in the negative control group. However, compared to CA-2-P100 infection, CA-2-MP120 yielded consistently higher viremia kinetics and enhanced antibody responses in pigs. All pigs inoculated with CA-2-MP120 developed viremia and seroconverted to PRRSV. During 20 passages in PAM cells, CA-2-MP120 acquired 15 amino acid changes that were mostly distributed in nsp2 and minor structural protein-coding regions. Among these changes, 6 mutations represented reversions to the sequences of the reference CA-2 and parental CA-2-P20 strains. These genetic drifts may be hypothetical molecular markers associated with PRRSV macrophage tropism and virulence. Our results indicate that the PAM-passaged CA-2-MP120 strain is a potential candidate for developing a live, attenuated PRRSV vaccine.
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Affiliation(s)
- Seung-Chul Lee
- Choongang Vaccine Laboratory, Daejeon 34055, Korea.,College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
| | - Sunhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Korea
| | - Gun-Woo Yoo
- Choongang Vaccine Laboratory, Daejeon 34055, Korea
| | | | - Yun-Hee Noh
- Choongang Vaccine Laboratory, Daejeon 34055, Korea
| | - Chang Eon Park
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Korea
| | - Jae-Ho Shin
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Korea
| | | | - Shien-Young Kang
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Korea
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Comparison of Asian porcine high fever disease isolates of porcine reproductive and respiratory syndrome virus to United States isolates for their ability to cause disease and secondary bacterial infection in swine. Vet Microbiol 2017; 203:6-17. [PMID: 28619168 DOI: 10.1016/j.vetmic.2017.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 11/21/2022]
Abstract
Epidemiologic data from Asian outbreaks of highly-pathogenic (HP) porcine reproductive and respiratory syndrome virus (PRRSV) suggest that disease severity was associated with both the virulence of the PRRSV isolates and secondary bacterial infections. Previous reports have indicated that U.S. isolates of PRRSV predispose to secondary bacterial infections as well, but the severity of disease that occurred in Asia in pigs infected with these HP-PRRSV strains has not been reported in the U.S. The objectives of this research were to compare the pathogenesis of Asian and U.S. PRRSV isolates with regard to their ability to cause disease and predispose to secondary bacterial infections in swine. To address these objectives groups of pigs were infected with 1 of 2 Asian HP-PRRSV strains (rJXwn06 or rSRV07) or 1 of 2 U.S. PRRSV strains (SDSU73 or VR-2332) alone or in combination with Streptococcus suis, Haemophilus parasuis, and Actinobacillus suis. Pigs infected with rJXwn06 exhibited the most severe clinical disease while the pigs infected with rSRV07 and SDSU73 exhibited moderate clinical disease, and pigs infected with VR-2332 exhibited minimal clinical signs. The frequency of secondary bacterial pneumonia was associated with the clinical severity induced by the PRRSV strains evaluated. The levels of proinflammatory cytokines in the serum were often lower for pigs coinfected with virus and bacteria compared to pigs infected with PRRSV alone indicating an alteration in the immune response in coinfected pigs. Combined our results demonstrate that severity of disease appears to be dependent on virulence of the PRRSV strain, and development of secondary bacterial infection.
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Lee SC, Choi HW, Nam E, Noh YH, Lee S, Lee YJ, Park GS, Shin JH, Yoon IJ, Kang SY, Lee C. Pathogenicity and genetic characteristics associated with cell adaptation of a virulent porcine reproductive and respiratory syndrome virus nsp2 DEL strain CA-2. Vet Microbiol 2016; 186:174-88. [PMID: 27016772 DOI: 10.1016/j.vetmic.2016.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/03/2016] [Accepted: 03/03/2016] [Indexed: 02/06/2023]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is the most common and world-widespread viral pathogen of swine. We previously reported genomic sequences and pathogenicity of type 2 Korean PRRSV strains belonging to the virulent lineage 1 family, which contain remarkable amino acid deletions in nonstructural protein 2 (nsp2 DEL) compared to VR-2332. Here, a virulent type 2 Korean PRRSV nsp2 DEL strain, CA-2, was serially propagated in MARC-145 cells for up to 100 passages (CA-2-P100). As the passage number increased, the phenotypic characteristics of cell-adapted CA-2 strains were altered, in terms of higher viral titers and larger plaque sizes compared to the parental virus. Pro-inflammatory cytokine genes, including TNF-α, IL-8, MCP-1, and MCP-2, were found to be significantly down-regulated in PAM cells with the CA-2-P100 strain compared to its parental nsp2 DEL virus. Animal inoculation studies demonstrated that the virulence of CA-2-P100 was reduced significantly, with showing normal weight gain, body temperatures, and lung lesions comparable to the control group. Furthermore, high-passage CA-2-P100 showed declined and transient viremia kinetics, as well as delayed and low PRRSV-specific antibody responses in infected pigs. In addition, we determined whole genome sequences of low to high-passage derivatives of CA-2. The nsp2 DEL pattern was conserved for 100 passages, whereas no other deletions or insertions arose during the cell adaptation process. However, CA-2-P100 possessed 54 random nucleotide substitutions that resulted in 27 amino acid changes distributed throughout the genome, suggesting that these genetic drifts provide a possible molecular basis correlated with the cell-adapted features in vitro and the attenuated phenotype in vivo. Taken together, our data indicate that the cell-attenuated CA-2-P100 strain is a promising candidate for developing a safe and effective live PRRSV vaccine.
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Affiliation(s)
- Seung-Chul Lee
- Choongang Vaccine Laboratory, Daejeon 34055, Republic of Korea; College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Hwan-Won Choi
- Choongang Vaccine Laboratory, Daejeon 34055, Republic of Korea
| | - Eeuri Nam
- Choongang Vaccine Laboratory, Daejeon 34055, Republic of Korea
| | - Yun-Hee Noh
- Choongang Vaccine Laboratory, Daejeon 34055, Republic of Korea
| | - Sunhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Yoo Jin Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Gun-Seok Park
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jae-Ho Shin
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 41566, Republic of Korea
| | - In-Joong Yoon
- Choongang Vaccine Laboratory, Daejeon 34055, Republic of Korea
| | - Shien-Young Kang
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Republic of Korea.
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea.
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Genomic analysis and pathogenic characteristics of Type 2 porcine reproductive and respiratory syndrome virus nsp2 deletion strains isolated in Korea. Vet Microbiol 2014; 170:232-45. [PMID: 24646599 DOI: 10.1016/j.vetmic.2014.02.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 02/06/2014] [Accepted: 02/17/2014] [Indexed: 11/20/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine virus that exhibits genetic and pathogenic heterogeneity among isolates. The present study was conducted to determine the complete genome sequence and pathogenicity of two Korean type 2 PRRSV nonstructural protein 2 (nsp2) deletion mutants, CA-2 and KNU-12-KJ4. The full-length genomes of CA-2 and KNU-12-KJ4 were determined to be 15,018 and 15,019 nucleotides in length, excluding the poly(A) tail, respectively, which were 393- or 392-nucleotide shorter than that of the type 2 NA prototype strain VR-2332 due to the presence of notable large deletions within the nsp2 gene. The genomes of CA-2 and KNU-12-KJ4 consisted of a 189- or 190-nucleotide 5' untranslated region (UTR), a 14,677-nucleotide protein-coding region, and a 151-nucleotide 3' UTR. Whole genome evaluation revealed that the nucleotide sequences of CA-2 and KNU-12-KJ4 are most similar to each other (10.7% sequence divergence), and then to the Korean strain CA-1 (11.3% sequence divergence) and the US strain MN184C (13.1% sequence divergence), respectively. To evaluate the in vitro immunity of nsp2 deletion variants, we sought to explore alteration of inflammatory cytokine and chemokine expression in PAM-pCD163 cells infected with each virus strain using quantitative real-time RT-PCR. Cytokine genes including IL-8, IL-10, and TNF-α, and chemokines such as MCP-1 and RANTES were found to be significantly elevated in nsp2 deletion virus-infected PAM cells. In contrast, expression of interferons (IFN-β, γ, and λ) and antiviral genes including ISG-15, -54, and -56 were unchanged or down-regulated in PAM cells infected with the nsp2 deletion mutants. Animal studies to assess the pathogenicity of nsp2 deletion PRRSVs demonstrated that both CA-2 and KNU-12-KJ4 strains notably produce weight loss in infected pigs. Furthermore, the nsp2 deletion mutants replicated well in pigs with significantly increased and prolonged viremia kinetics. Taken together, our results indicate that, among the three isolates, the outcome of in vitro and in vivo infection by CA-2 and KNU-12-KJ4 is comparable, suggesting that the large nsp2 deletion may be one of the viral genetic determinants contributing to PRRSV pathogenicity.
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Brockmeier SL, Loving CL, Vorwald AC, Kehrli ME, Baker RB, Nicholson TL, Lager KM, Miller LC, Faaberg KS. Genomic sequence and virulence comparison of four Type 2 porcine reproductive and respiratory syndrome virus strains. Virus Res 2012; 169:212-21. [PMID: 23073232 DOI: 10.1016/j.virusres.2012.07.030] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 07/20/2012] [Accepted: 07/30/2012] [Indexed: 02/05/2023]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a ubiquitous and costly virus that exhibits substantial sequence and virulence disparity among diverse isolates. In this study, we compared the whole genomic sequence and virulence of 4 Type 2 PRRSV isolates. Among the 4 isolates, SDSU73, MN184, and NADC30 were all clearly more virulent than NADC31, and among the 3 more virulent isolates, there were subtle differences based on viral replication, lung lesions, lymphadenopathy, febrile response, decreased weight gains, and cytokine responses in the lung. Lesions consistent with bacterial bronchopneumonia were present to varying degrees in pigs infected with PRRSV, and bacteria typically associated with the porcine respiratory disease complex were isolated from the lung of these pigs. Genomic sequence evaluation indicates that SDSU73 is most similar to the nucleotide sequence of JA142, the parental strain of Ingelvac(®) PRRS ATP, while the nucleotide sequences of NADC30 and NADC31 are more similar to strain MN184. Both the NADC30 and NADC31 isolates of PRRSV, isolated in 2008, maintain the nonstructural protein 2 (nsp2) deletion seen in MN184 that was isolated in 2001, but NADC31 has two additional 15 and 36 nucleotide deletions, and these strains are 8-14% different on a nucleotide basis from the MN184 strain. These results indicate that newer U.S. Type 2 strains still exhibit variability in sequence and pathogenicity and although PRRSV strains appear to be reducing the size of the nsp2 over time, this does not necessarily mean that the strain is more virulent.
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Affiliation(s)
- Susan L Brockmeier
- Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA 50010, United States.
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Tian K, Yu X, Zhao T, Feng Y, Cao Z, Wang C, Hu Y, Chen X, Hu D, Tian X, Liu D, Zhang S, Deng X, Ding Y, Yang L, Zhang Y, Xiao H, Qiao M, Wang B, Hou L, Wang X, Yang X, Kang L, Sun M, Jin P, Wang S, Kitamura Y, Yan J, Gao GF. Emergence of fatal PRRSV variants: unparalleled outbreaks of atypical PRRS in China and molecular dissection of the unique hallmark. PLoS One 2007; 2:e526. [PMID: 17565379 PMCID: PMC1885284 DOI: 10.1371/journal.pone.0000526] [Citation(s) in RCA: 791] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 05/22/2007] [Indexed: 11/18/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a severe viral disease in pigs, causing great economic losses worldwide each year. The causative agent of the disease, PRRS virus (PRRSV), is a member of the family Arteriviridae. Here we report our investigation of the unparalleled large-scale outbreaks of an originally unknown, but so-called "high fever" disease in China in 2006 with the essence of PRRS, which spread to more than 10 provinces (autonomous cities or regions) and affected over 2,000,000 pigs with about 400,000 fatal cases. Different from the typical PRRS, numerous adult sows were also infected by the "high fever" disease. This atypical PRRS pandemic was initially identified as a hog cholera-like disease manifesting neurological symptoms (e.g., shivering), high fever (40-42 degrees C), erythematous blanching rash, etc. Autopsies combined with immunological analyses clearly showed that multiple organs were infected by highly pathogenic PRRSVs with severe pathological changes observed. Whole-genome analysis of the isolated viruses revealed that these PRRSV isolates are grouped into Type II and are highly homologous to HB-1, a Chinese strain of PRRSV (96.5% nucleotide identity). More importantly, we observed a unique molecular hallmark in these viral isolates, namely a discontinuous deletion of 30 amino acids in nonstructural protein 2 (NSP2). Taken together, this is the first comprehensive report documenting the 2006 epidemic of atypical PRRS outbreak in China and identifying the 30 amino-acid deletion in NSP2, a novel determining factor for virulence which may be implicated in the high pathogenicity of PRRSV, and will stimulate further study by using the infectious cDNA clone technique.
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Affiliation(s)
- Kegong Tian
- China Animal Disease Control Center, Beijing, China
- * To whom correspondence should be addressed. E-mail: (KT); (GG)
| | - Xiuling Yu
- China Animal Disease Control Center, Beijing, China
| | - Tiezhu Zhao
- China Animal Disease Control Center, Beijing, China
| | - Youjun Feng
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Graduate University, Chinese Academy of Sciences, Beijing, China
| | - Zhen Cao
- China Animal Disease Control Center, Beijing, China
| | | | - Yan Hu
- China Animal Disease Control Center, Beijing, China
| | - Xizhao Chen
- China Animal Disease Control Center, Beijing, China
| | - Dongmei Hu
- China Animal Disease Control Center, Beijing, China
| | - Xinsheng Tian
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Graduate University, Chinese Academy of Sciences, Beijing, China
| | - Di Liu
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuo Zhang
- China Animal Disease Control Center, Beijing, China
| | - Xiaoyu Deng
- China Animal Disease Control Center, Beijing, China
| | - Yinqiao Ding
- China Animal Disease Control Center, Beijing, China
| | - Lu Yang
- China Animal Disease Control Center, Beijing, China
| | - Yunxia Zhang
- China Animal Disease Control Center, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Haixia Xiao
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Graduate University, Chinese Academy of Sciences, Beijing, China
| | - Mingming Qiao
- China Animal Disease Control Center, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Bin Wang
- China Animal Disease Control Center, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lili Hou
- China Animal Disease Control Center, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | | | - Xinyan Yang
- China Animal Disease Control Center, Beijing, China
| | - Liping Kang
- China Animal Disease Control Center, Beijing, China
| | - Ming Sun
- China Animal Disease Control Center, Beijing, China
| | - Ping Jin
- China Animal Disease Control Center, Beijing, China
| | - Shujuan Wang
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yoshihiro Kitamura
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jinghua Yan
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - George F. Gao
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * To whom correspondence should be addressed. E-mail: (KT); (GG)
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