Background and objective: Dengue is a major public
health problem in tropical and subtropical countries.
The four dengue virus serotypes can cause a wide
range of mild to severe diseases. Many research and
development efforts are ongoing to find a better
effective and accessible version of vaccine,
therapeutic agent, or diagnostic tool. Envelope (E)
protein is a primary target for serologic diagnosis and
immunization. This work aimed to express and
characterize truncated E (rE74-118) protein of dengue
virus serotype 2 (DENV-2) in both in vitro and in vivo
properties.
Methods and results: A truncated DENV-2 envelope
E protein, amino acid sequence 74-118, encoding gene
was amplified and cloned into the pET-32b plasmid.
The recombinant plasmid was then expressed in
Escherichia coli (SHuffle) to produce the recombinant
protein rE74-118. Recombinant E protein in truncated
form (rE74-118) was successfully constructed,
expressed, and purified in the concentration of 5.8
mg/ml. The rE74-118 protein was tested for its specificity with an anti-E monoclonal antibodies and
dengue patient sera. Furthermore, its immunogenicity
in BALB/c mice was also tested. The results showed
that the rE74-118 protein can specifically react to
anti-E monoclonal antibodies and dengue patient sera.
This protein also induces the humoral response with
a low-level of neutralizing activity against DENV-2, as
well as the protein do not show enhancing activities
against all four serotypes.
Conclusion: The truncated rE74-118 protein showed
both antigenic and immunogenic properties in these
in vitro and in vivo characterizations.