DEFENCE RESEARCH ESTABLISHMENT SUFFIELDRALSTON (ALBERTA), Nagata, Les P., Long, Melissa C., Schmaltz, Fay L., Rayner, George A., Wong, Jonathan P., DEFENCE RESEARCH ESTABLISHMENT SUFFIELDRALSTON (ALBERTA), Nagata, Les P., Long, Melissa C., Schmaltz, Fay L., Rayner, George A., and Wong, Jonathan P.
Previously, the complete genome of western equine encephalitis virus had been cloned and sequenced. This paper describes mammalian expression vectors pCXH-3 and pVHX-6, in which expression of the structural genes of western equine encephalitis virus have been placed under the control of the mammalian CMV promoter. When pCXH-3 or pVHX-6 is expressed using a cell-free transcription/translation system, in vitro, authentic structural proteins of western equine encephalitis virus are produced as verified by reactivity with monoclonal antibodies developed to western equine encephalitis virus. These vectors can also be complexed with liposomes and administered to mammalian cell culture. The viral envelope proteins were functionally expressed, as determined by histochemical staining with monoclonal antibodies which recognize WEE antigens. In addition, when pCXH-3 or pVHX-6 is administered intraepidermally and intramuscularly% to mice, a protective immune response is induced. Immunized mice had a significantly reduced risk of infection, against a subsequent intranasal challenge with western equine encephalitis virus. Development of a DNA vaccine to western equine encephalitis virus is promising. In a similar manner, DNA vaccines to related alphaviruses (Venezuelan and eastern equine encephalitis viruses) could also be developed.