title: Antiviral activity produced by an IPNV-carrier EPC cell culture confers resistance to VHSV infection.
abstract: Infectious pancreatic necrosis virus (IPNV), a fish birnavirus, can establish a persistent infection on epithelioma papulosum cyprinid (EPC) cells producing a carrier state where a small fraction of IPNV-infected cells is maintained in the culture after continuous subculture. The EPC(IPNV) cells are resistant to challenge with IPNV as well as to challenge with viral hemorrhagic septicemia virus (VHSV), a rhabdovirus. In this work, the antiviral effect of the IPNV carrier culture conditioned medium (EPC(IPNV)-CM) was tested and analyzed in detail. EPC cells treated with the carrier culture supernatant become protected against VHSV challenge. Size-fractionation by filtration and acid and heat treatment showed that the IPNV persistently infected cells release an acid-resistant soluble factor in the molecular weight fraction bellow 50 kDa. The capacity of the EPC(IPNV)-CM to induce cytokine genes in EPC cells was also determined by real-time RT-PCR. We found that there is a positive correlation between up-regulation of mx gene expression in EPC cells treated with EPC(IPNV)-CM and protection against VHSV challenge. Our findings indicate that the control of IPNV multiplication in the carrier culture as well as the interference with rhabdovirus replication are connected to the production and release of an antiviral (interferon-like) factor to the medium.
authors.affiliation: Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Av. Universidad s/n, 03202 Elche, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Jurado
authors.forename: Pablo
authors.initials: P
authors.lastname: García-Valtanen
authors.forename: Amparo
authors.initials: A
authors.lastname: Estepa
authors.forename: Luis
authors.initials: L
authors.lastname: Perez
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003530:Cyprinidae; D060467:Disease Resistance; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000821:virology; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology; D018061:Infectious pancreatic necrosis virus / Q000502:physiology*; D007372:Interferons / Q000235:genetics / Q000276:immunology; D029141:Novirhabdovirus / Q000502:physiology*; D018353:Rhabdoviridae Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary* / Q000821:virology
chemical_list: D029941:Fish Proteins; D007372:Interferons
keywords: EPC cell line; IPNV; Interferon-like; VHSV; Viral interference