title: Identification of a new cell line permissive to porcine reproductive and respiratory syndrome virus infection and replication which is phenotypically distinct from MARC-145 cell line.
abstract: BACKGROUND
  Airborne transmitted pathogens, such as porcine reproductive and respiratory syndrome virus (PRRSV), need to interact with host cells of the respiratory tract in order to be able to enter and disseminate in the host organism. Pulmonary alveolar macrophages (PAM) and MA104 derived monkey kidney MARC-145 cells are known to be permissive to PRRSV infection and replication and are the most studied cells in the literature. More recently, new cell lines developed to study PRRSV have been genetically modified to make them permissive to the virus. The SJPL cell line origin was initially reported to be epithelial cells of the respiratory tract of swine. Thus, the goal of this study was to determine if SJPL cells could support PRRSV infection and replication in vitro.
  
  
  RESULTS
  The SJPL cell growth was significantly slower than MARC-145 cell growth. The SJPL cells were found to express the CD151 protein but not the CD163 and neither the sialoadhesin PRRSV receptors. During the course of the present study, the SJPL cells have been reported to be of monkey origin. Nevertheless, SJPL cells were found to be permissive to PRRSV infection and replication even if the development of the cytopathic effect was delayed compared to PRRSV-infected MARC-145 cells. Following PRRSV replication, the amount of infectious viral particles produced in SJPL and MARC-145 infected cells was similar. The SJPL cells allowed the replication of several PRRSV North American strains and were almost efficient as MARC-145 cells for virus isolation. Interestingly, PRRSV is 8 to 16 times more sensitive to IFNα antiviral effect in SJPL cell in comparison to that in MARC-145 cells. PRRSV induced an increase in IFNβ mRNA and no up regulation of IFNα mRNA in both infected cell types. In addition, PRRSV induced an up regulation of IFNγ and TNF-α mRNAs only in infected MARC-145 cells.
  
  
  CONCLUSIONS
  In conclusion, the SJPL cells are permissive to PRRSV. In addition, they are phenotypically different from MARC-145 cells and are an additional tool that could be used to study PRRSV pathogenesis mechanisms in vitro.
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP), Centre de recherche en infectiologie porcine (CRIP), Faculté de médecine vétérinaire Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, J2S 7C6, Québec, Canada.
authors.forename: Chantale
authors.initials: C
authors.lastname: Provost
authors.forename: Jian Jun
authors.initials: JJ
authors.lastname: Jia
authors.forename: Nedzad
authors.initials: N
authors.lastname: Music
authors.forename: Cynthia
authors.initials: C
authors.lastname: Lévesque
authors.forename: Marie-Ève
authors.initials: MÈ
authors.lastname: Lebel
authors.forename: Jérôme R E
authors.initials: JR
authors.lastname: del Castillo
authors.forename: Mario
authors.initials: M
authors.lastname: Jacques
authors.forename: Carl A
authors.initials: CA
authors.lastname: Gagnon
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D016898:Interferon-alpha / Q000494:pharmacology; D019316:Porcine respiratory and reproductive syndrome virus / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D011991:Receptors, Virus / Q000378:metabolism; D013552:Swine; D014764:Viral Proteins / Q000378:metabolism; D056189:Viral Tropism; D057074:Virus Release; D014779:Virus Replication / Q000187:drug effects
chemical_list: D016207:Cytokines; D016898:Interferon-alpha; D012333:RNA, Messenger; D011991:Receptors, Virus; D014764:Viral Proteins; D053148:Caspase 3; D053179:Caspase 7