Construction and Evaluation of a Polyvalent Genetically Engineered Vaccine Candidate for VEE.
Abstract
The goal of thIs project was to produce a safe and effective molecularly cloned live virus vaccine for Venezuelan equine encephalitis virus (TEE). A panel of attenuating mutations was generated using biological selection techniques and in vitro mutagenesis targeted to regions conserved among alphaviruses. The full-length cDNA clone of the virulent Trinidad donkey strain of VEE was altered by site-directed mutagenesis to contain multiple attenuating mutations. Several multiple mutant clones were constructed, and progeny viruses, produced by transfection of cultured cells with RNA transcripts, were tested for virulence and immunogenicity in rodent models. The candidate vaccine, designated V3526, contains a deletion of the PE2 cleavage signal in conjunction with a second mutation at El position 253, from phe to ser. V3526 is avirulent in mice inoculated subcutaneously, intraperitoneally and intranasally, and is highly attenuated even when inoculated directly into the brain. Immunization with V3526 induces strong protection in mice against both parenteral and intranasal challenge with virulent VEE. Construction of attenuated mutants like V3526 may be possible for other alphaviruses, all of which contain similar PE2 cleavage signals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1997
- Accession Number
- ADB228895
Entities
People
- Robert E. Johnston
Organizations
- University of North Carolina at Chapel Hill