title: Packaging of porcine reproductive and respiratory syndrome virus replicon RNA by a stable cell line expressing its nucleocapsid protein.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV), a member of the Arteriviridae family, is one of the most common and economically important swine pathogens. Although both live-attenuated and killed-inactivated vaccines against the virus have been available for a decade, PRRSV is still a major problem in the swine industry worldwide. To explore the possibility of producing single-round infectious PRRSV replicon particles as a potential vaccine strategy, we have now generated two necessary components: 1) a stable cell line (BHK/Sinrepl9/PRRSV-N) that constitutively expresses the viral nucleocapsid (N) protein localized to the cytoplasm and the nucleolus and 2) a PRRSV replicon vector (pBAC/PRRSV/Replicon-AN) with a 177-nucleotide deletion, removing the 3'-half portion of ORF7 in the viral genome, from which the self-replicating propagation-defective replicon RNAs were synthesized in vitro by SP6 polymerase run-off transcription. Transfection of this replicon RNA into N protein-expressing BHK-21 cells led to the secretion of infectious particles that packaged the replicon RNA, albeit with a low production efficiency of 0.4 × 10(2) to 1.1 × 10(2) infectious units/ml; the produced particles had only single-round infectivity with no cell-to-cell spread. This trans-complementation system for PRRSV provides a useful platform for studies to define the packaging signals and motifs present within the viral genome and N protein, respectively, and to develop viral replicon-based antiviral vaccines that will stop the infection and spread of this pathogen.
authors: Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, 361-763, Republic of Korea.
authors: Byung-Hak
authors: BH
authors: Song
authors: Jeong-Min
authors: JM
authors: Kim
authors: Jin-Kyoung
authors: JK
authors: Kim
authors: Han-Saem
authors: HS
authors: Jang
authors: Gil-Nam
authors: GN
authors: Yun
authors: Eun-Jin
authors: EJ
authors: Choi
authors: Jae-Young
authors: JY
authors: Song
authors: Sang-Im
authors: SI
authors: Yun
authors: Young-Min
authors: YM
authors: Lee
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000378:metabolism*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000502:physiology*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012093:Replicon / Q000235:genetics / Q000502:physiology; D014162:Transfection; D014765:Viral Vaccines; D014771:Virion / Q000378:metabolism / Q000502:physiology; D019065:Virus Assembly
chemical_list: D019590:Nucleocapsid Proteins; D012367:RNA, Viral; D014765:Viral Vaccines