Genomic analysis and pathogenic characteristics of Type 2 porcine reproductive and respiratory syndrome virus nsp2 deletion strains isolated in Korea
| Autor: | Yoo Jin Lee, Yun-Hee Noh, In-Joong Yoon, Shien-Young Kang, Hyun Soo Kim, Eeuri Nam, Changhee Lee, Young-Ki Choi, Hwan-Won Choi, Seung-Chul Lee |
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| Rok vydání: | 2014 |
| Předmět: |
Untranslated region
Chemokine Swine viruses Molecular Sequence Data Porcine Reproductive and Respiratory Syndrome Viremia Genome Viral Viral Nonstructural Proteins Antibodies Viral Microbiology Genome Cell Line Random Allocation Sequence Homology Nucleic Acid Republic of Korea medicine Animals Porcine respiratory and reproductive syndrome virus Gene Sequence Deletion Whole genome sequencing Genetics General Veterinary biology Gene Expression Profiling General Medicine medicine.disease Porcine reproductive and respiratory syndrome virus biology.organism_classification Virology In vitro Gene Expression Regulation biology.protein Cytokines |
| Zdroj: | Veterinary Microbiology. 170:232-245 |
| ISSN: | 0378-1135 |
| DOI: | 10.1016/j.vetmic.2014.02.027 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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