title: A recombinant DNA vaccine protects mice deficient in the alpha/beta interferon receptor against lethal challenge with Usutu virus.
abstract: Usutu virus (USUV) is a mosquito-borne flavivirus whose circulation had been confined to Africa since it was first detected in 1959. However, in the last decade USUV has emerged in Europe causing episodes of avian mortality and sporadic severe neuroinvasive infections in humans. Remarkably, adult laboratory mice exhibit limited susceptibility to USUV infection, which has impaired the analysis of the immune responses, thus complicating the evaluation of virus-host interactions and of vaccine candidates against this pathogen. In this work, we showed that mice deficient in the alpha/beta interferon receptor (IFNAR (-/-) mice) were highly susceptible to USUV infection and provided a lethal challenge model for vaccine testing. To validate this infection model, a plasmid DNA vaccine candidate encoding the precursor of membrane (prM) and envelope (E) proteins of USUV was engineered. Transfection of cultured cells with this plasmid resulted in expression of USUV antigens and the assembly and secretion of small virus-like particles also known as recombinant subviral particles (RSPs). A single intramuscular immunization with this plasmid was sufficient to elicit a significant level of protection against challenge with USUV in IFNAR (-/-) mice. The characterization of the humoral response induced revealed that DNA vaccination primed anti-USUV antibodies, including neutralizing antibodies. Overall, these results probe the suitability of IFNAR (-/-) mice as an amenable small animal model for the study of USUV host virus interactions and vaccine testing, as well as the feasibility of DNA-based vaccine strategies for the control of this pathogen.
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain; Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Martín-Acebes
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
authors.forename: Ana-Belén
authors.initials: AB
authors.lastname: Blázquez
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cañas-Arranz
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Vázquez-Calvo
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Merino-Ramos
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain.
authors.forename: Estela
authors.initials: E
authors.lastname: Escribano-Romero
authors.affiliation: Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Sobrino
authors.affiliation: Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain. Electronic address: jcsaiz@inia.es.
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Saiz
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology; D018349:Encephalitis Viruses, Japanese; D018177:Flavivirus Infections / Q000517:prevention & control*; D022321:Japanese Encephalitis Vaccines / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D053633:Receptor, Interferon alpha-beta / Q000235:genetics*; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D022321:Japanese Encephalitis Vaccines; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D053633:Receptor, Interferon alpha-beta
keywords: Antibodies; DNA vaccine; Flavivirus; IFNAR mice; Usutu virus