title: In vitro analysis of the factors contributing to the antiviral state induced by a plasmid encoding the viral haemorrhagic septicaemia virus glycoprotein G in transfected trout cells.
abstract: We have found out that transfection of the RTG-2 cell line with the viral haemorrhagic septicaemia virus (VHSV) glycoprotein G (G(VHSV))-coding plasmid induces an anti-VHSV state, similar to that induced by poly I:C. Taking the advantage of the constitutive expression of toll-like receptor 9 gene (tlr9) in RTG-2 cells, we have investigated whether this antiviral state was induced by the cytosine-phosphodiester-guanine (CpG) motifs present in the plasmid DNA, by the endogenous expression of G(VHSV) protein or by both elements. For that, we have analysed the expression profile of the rainbow trout tlr9 and several genes related to TLR9-mediated immune response in the absence or presence of a lysosomotropic drug that specifically blocks TLR9-CpG DNA interaction. The results suggested that the high levels of cell protection conferred by a plasmid encoding G(VHSV) gene are due to G(VHSV) rather than to the CpG motifs within plasmid DNA. Therefore, plasmid DNA might not play a key role in the immune response elicited by DNA vaccines or perhaps other receptors instead TLR9 could be implicated in CpG motifs recognition and signalling. In addition, since RTG-2 cells express tlr9 gene, this cell line could be a good tool for screening TLR9 agonists, such as the immunomodulatory oligonucleotides (IMOs), as fish DNA vaccine adjuvants.
authors.affiliation: IBMC, Miguel Hernández University, 03202 Elche, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Ortega-Villaizan
authors.forename: V
authors.initials: V
authors.lastname: Chico
authors.forename: A
authors.initials: A
authors.lastname: Martinez-Lopez
authors.forename: A
authors.initials: A
authors.lastname: Falco
authors.forename: L
authors.initials: L
authors.lastname: Perez
authors.forename: J M
authors.initials: JM
authors.lastname: Coll
authors.forename: A
authors.initials: A
authors.lastname: Estepa
mesh_terms: D000818:Animals; D002460:Cell Line; D020869:Gene Expression Profiling; D031941:Hemorrhagic Septicemia, Viral / Q000276:immunology*; D017686:Oncorhynchus mykiss / Q000276:immunology*; D010957:Plasmids; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: C096089:G protein, viral hemorrhagic septicemia virus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins