Vectors expressing chimeric Japanese encephalitis dengue 2 viruses

Area of Science:

• Virology
• Molecular Biology
• Vaccinology

Background:

• Self-replicating RNA (replicon) vectors derived from flaviviruses are valuable tools for gene expression and vaccine development.
• Japanese encephalitis virus (JEV) and Dengue 2 virus (DENV-2) are significant human pathogens within the Flaviviridae family.

Purpose of the Study:

• To construct and characterize novel JEV-based expression vectors containing DENV-2 genes.
• To evaluate the potential of these chimeric viruses for gene expression and as vaccine candidates.

Main Methods:

• Construction of two JEV vectors (pJED2, pJED2-1770) with full or partial replacement of PrM/M-E genes with DENV-2 sequences.
• Transfection of vectors into BHK-21 cells to produce chimeric viruses (JED2V, JED2-1770V).
• Characterization of chimeric viruses using cell culture (C6/36, BHK-21), RT-PCR, sequencing, immunofluorescence assay (IFA), Western blot, and immunogenicity studies in mice.

Main Results:

• Successfully generated infectious chimeric JEV-DENV-2 viruses (JED2V, JED2-1770V).
• Chimeric viruses exhibited cytopathic effects (CPE) in C6/36 cells but not BHK-21 cells.
• Molecular analyses confirmed the chimeric nature of the viruses.
• Immunogenicity studies in mice demonstrated the production of DENV-2 E protein-specific IgG antibodies with a neutralization titer of 10.

Conclusions:

• JEV-based expression vectors are functional and can be engineered to express heterologous genes from other flaviviruses.
• The developed chimeric JEV-DENV-2 viruses are viable candidates for further research in gene expression and vaccine development against flaviviral diseases.