MICE IMMUNIZED WITH A DENGUE TYPE-2 VIRUS-E AND NS1 FUSION PROTEIN MADE IN ESCHERICHIA-COLI ARE PROTECTED AGAINST LETHAL DENGUE VIRUS-INFECTION

A gene fragment encoding the C-terminal 204 amino acids (AA) from the structural envelope glycoprotein (E) and the N-terminal 65 AA from non -structural protein one (NS1) of dengue type 2 virus (DEN-2) was expre ssed in Escherichia coli (E. coli) as a fusion protein with staphyloco ccal protein A. The recombinant fusion protein was purified and analys ed for its antigenicity, its immunogenicity and its ability to protect mice against lethal challenge with live DEN-2 virus. The recombinant protein was found to be reactive with anti-DEN-2 polyclonal and monocl onal antibodies. Mice immunized with the purified fusion protein made anti-DEN-2 antibodies measured by the hemagglutination-inhibition (HI) and neutralization (N) tests, and were protected against lethal chall enge with DEN-2 virus administered by intracranial inoculation.