title: Vaccination of mice using the West Nile virus E-protein in a DNA prime-protein boost strategy stimulates cell-mediated immunity and protects mice against a lethal challenge.
abstract: West Nile virus (WNV) is a mosquito-borne flavivirus that is endemic in Africa, the Middle East, Europe and the United States. There is currently no antiviral treatment or human vaccine available to treat or prevent WNV infection. DNA plasmid-based vaccines represent a new approach for controlling infectious diseases. In rodents, DNA vaccines have been shown to induce B cell and cytotoxic T cell responses and protect against a wide range of infections. In this study, we formulated a plasmid DNA vector expressing the ectodomain of the E-protein of WNV into nanoparticles by using linear polyethyleneimine (lPEI) covalently bound to mannose and examined the potential of this vaccine to protect against lethal WNV infection in mice. Mice were immunized twice (prime--boost regime) with the WNV DNA vaccine formulated with lPEI-mannose using different administration routes (intramuscular, intradermal and topical). In parallel a heterologous boost with purified recombinant WNV envelope (E) protein was evaluated. While no significant E-protein specific humoral response was generated after DNA immunization, protein boosting of DNA-primed mice resulted in a marked increase in total neutralizing antibody titer. In addition, E-specific IL-4 T-cell immune responses were detected by ELISPOT after protein boost and CD8(+) specific IFN-γ expression was observed by flow cytometry. Challenge experiments using the heterologous immunization regime revealed protective immunity to homologous and virulent WNV infection.
authors: Laboratory of Gene Therapy, Faculty of Veterinary Sciences, Ghent University, Merelbeke, Belgium.
authors: Marina
authors: M
authors: De Filette
authors: Institute of Virology, University of Zurich, Zurich, Switzerland.
authors: Silke
authors: S
authors: Soehle
authors: Department of Immunology, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany.
authors: Sebastian
authors: S
authors: Ulbert
authors: Departments of Medicine, Molecular Microbiology and Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors: Justin
authors: J
authors: Richner
authors: Departments of Medicine, Molecular Microbiology and Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America.
authors: Michael S
authors: MS
authors: Diamond
authors: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors: Alessandro
authors: A
authors: Sinigaglia
authors: Department of Molecular Medicine, University of Padova, Padova, Italy.
authors: Luisa
authors: L
authors: Barzon
authors: Operational Direction Interactions and Surveillance, Veterinary and Agrochemical Research Centre (CODA/CERVA), Brussels, Belgium.
authors: Stefan
authors: S
authors: Roels
authors: Genetic Immunity, Budapest, Hungary and McLean, Virginia, United States of America.
authors: Julianna
authors: J
authors: Lisziewicz
authors: Genetic Immunity, Budapest, Hungary and McLean, Virginia, United States of America.
authors: Orsolya
authors: O
authors: Lorincz
authors: Laboratory of Gene Therapy, Faculty of Veterinary Sciences, Ghent University, Merelbeke, Belgium.
authors: Niek N
authors: NN
authors: Sanders
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D005260:Female; D007111:Immunity, Cellular; D007114:Immunization; D007117:Immunization, Secondary; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry; D018418:Th2 Cells / Q000276:immunology; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014901:West Nile Fever / Q000276:immunology* / Q000401:mortality / Q000517:prevention & control*; D053060:West Nile Virus Vaccines / Q000009:adverse effects / Q000276:immunology*; D014902:West Nile virus / Q000235:genetics / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D053060:West Nile Virus Vaccines