title: Constitutively Active IRF7/IRF3 Fusion Protein Completely Protects Swine against Foot-and-Mouth Disease.
abstract: Foot-and-mouth disease (FMD) remains one of the most devastating livestock diseases around the world. Several serotype-specific vaccine formulations exist, but they require about 5 to 7 days to induce protective immunity. Our previous studies have shown that a constitutively active fusion protein of porcine interferon (IFN) regulatory factors (IRF) 7 and 3 [IRF7/3(5D)] strongly induced type I IFN and antiviral genes in vitro and prevented mortality in an FMD mouse model when delivered with a replication-defective adenoviral vector [Ad5-poIRF7/3(5D)]. Here, we demonstrate that pigs treated with 10(8), 10(9), or 10(10) PFU of Ad5-poIRF7/3(5D) 24 h before FMDV challenge were fully protected from FMD clinical signs and did not develop viremia, virus shedding or antibodies against FMDV nonstructural proteins. Pigs treated with Ad5-poIRF7/3(5D) had higher levels of IFN and antiviral activity in serum, and upregulated expression of several IFN-stimulated genes in peripheral blood mononuclear cells, compared to pigs treated with Ad5-Blue vector control. Importantly, treatment of porcine cultured cells with Ad5-poIRF7/3(5D) inhibited the replication of all 7 FMDV serotypes. In vitro experiments using cultured embryonic fibroblasts derived from IFN receptor knockout mice suggested that the antiviral response induced by Ad5-poIRF7/3(5D) was dependent on type I and III IFN pathways; however, experiments with mice demonstrated that a functional type I IFN pathway mediates Ad5-poIRF7/3(5D) protection conferred in vivo Our studies demonstrate that inoculation with Ad5-poIRF7/3(5D) completely protects swine against FMD by inducing a strong type I IFN response and highlights its potential application to rapidly and effectively prevent FMDV replication and dissemination.
  
  
  
  Foot-and-mouth disease virus (FMDV) causes a fast-spreading disease that affects farm animals, with economically and socially devastating consequences. Our study shows that inoculation with a constitutively active transcription factor, namely, a fusion protein of porcine interferon (IFN) regulatory factors (IRF) 7 and 3 delivered by an adenovirus vector [Ad5-poIRF7/3(5D)], is a new effective treatment to prevent FMD in swine. Animals pretreated with Ad5-poIRF7/3(5D) 1 day before being exposed to FMDV were completely protected from viral replication and clinical disease. It is noteworthy that the doses of Ad5-poIRF7/3(5D) required for protection are lower than those previously reported for similar approaches using Ad5 vectors delivering type I, II, or III IFN, suggesting that this novel strategy would be economically appealing to counteract FMD. Our results also indicate that a dynamic interplay among different components of pigs' innate immune defenses allows potent antiviral effects after Ad5-poIF7/3(5D) administration.
authors.affiliation: Foreign Animal Disease Research Unit, Agricultural Research Services, U.S. Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA Oak Ridge Institute for Science and Education, PIADC Research Participation Program, Oak Ridge, Tennessee, USA.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Ramírez-Carvajal
authors.affiliation: Foreign Animal Disease Research Unit, Agricultural Research Services, U.S. Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA Department of Pathobiology and Veterinary Science, CANR, University of Connecticut, Storrs, Connecticut, USA.
authors.forename: Fayna
authors.initials: F
authors.lastname: Diaz-San Segundo
authors.affiliation: Foreign Animal Disease Research Unit, Agricultural Research Services, U.S. Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA Oak Ridge Institute for Science and Education, PIADC Research Participation Program, Oak Ridge, Tennessee, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ramirez-Medina
authors.affiliation: Foreign Animal Disease Research Unit, Agricultural Research Services, U.S. Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA.
authors.forename: Luis L
authors.initials: LL
authors.lastname: Rodríguez
authors.affiliation: Foreign Animal Disease Research Unit, Agricultural Research Services, U.S. Department of Agriculture, Plum Island Animal Disease Center, Greenport, New York, USA teresa.delossantos@ars.usda.gov.
authors.forename: Teresa
authors.initials: T
authors.lastname: de Los Santos
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002460:Cell Line; D004337:Drug Carriers / Q000008:administration & dosage; D005536:Foot-and-Mouth Disease / Q000473:pathology / Q000517:prevention & control* / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology* / Q000502:physiology; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000378:metabolism*; D050839:Interferon Regulatory Factor-7 / Q000235:genetics / Q000378:metabolism*; D007370:Interferon Type I / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D016019:Survival Analysis; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control* / Q000821:virology; D014161:Transduction, Genetic; D016896:Treatment Outcome; D014779:Virus Replication
chemical_list: D004337:Drug Carriers; D050838:Interferon Regulatory Factor-3; D050839:Interferon Regulatory Factor-7; D007370:Interferon Type I; D007378:Interleukins; D011993:Recombinant Fusion Proteins