title: A DNA vaccine encoding the E protein of West Nile virus is protective and can be boosted by recombinant domain DIII.
abstract: West Nile Virus (WNV) is an emerging pathogenic flavivirus with increasing distribution worldwide. Birds are the natural host of the virus, but also mammals, including humans, can be infected. In some cases, a WNV infection can be associated with severe neurological symptoms. All currently available WNV vaccines are in the veterinary sector, and there is a need to develop safe and effective immunization technologies, which can also be used in humans. An alternative to current vaccination methods is DNA immunization. Most current DNA vaccine candidates against flaviviruses simultaneously express the viral envelope (E) and membrane (prM) proteins, which leads to the formation of virus-like particles. Here we generated a DNA plasmid, which expresses only the E-protein ectodomain. Vaccination of mice stimulated anti-WNV T-cell responses and neutralizing antibodies that were higher than those obtained after immunizing with a recombinant protein previously shown to be a protective WNV vaccine. A single dose of the plasmid was sufficient to protect animals from a lethal challenge with the virus. Moreover, immunogenicity could be boosted when DNA injection was followed by immunization with recombinant domain DIII of the E-protein. This resulted in significantly enhanced neutralizing antibody titers and a more prominent cellular immune response. The results suggest that the WNV E-protein is sufficient as a protective antigen in DNA vaccines and that protection can be significantly improved by adding a recombinant protein boost to the DNA prime.
authors: Vaccine Technologies Unit, Fraunhofer Institute for Cell Therapy and Immunology, Perlickstrasse 1, D-04103 Leipzig, Germany.
authors: Anne
authors: A
authors: Schneeweiss
authors: Stefan
authors: S
authors: Chabierski
authors: Mathias
authors: M
authors: Salomo
authors: Nicolas
authors: N
authors: Delaroque
authors: Samiya
authors: S
authors: Al-Robaiy
authors: Thomas
authors: T
authors: Grunwald
authors: Kurt
authors: K
authors: Bürki
authors: Uwe G
authors: UG
authors: Liebert
authors: Sebastian
authors: S
authors: Ulbert