A plasmid-based reporter system for live cell imaging of dengue virus infected cells

• A dengue viral cleavage site between NS4B and NS5 was cloned upstream of an SV40 nuclear localization sequences and GFP to produce a DENV reporter, pNS4B5-GFP.
• Dengue serotypes 1–4 cleaved the GFP from NS4B and GFP was localized to the nucleus of virally infected cells.
• Nuclear GFP correlated with dengue antigen staining.
• Time-lapse imaging showed nuclear localization occurred as early as 8 h post-infection.

Cell culture models are used widely to study the effects of dengue virus (DENV) on host cell function. Current methods of identification of cells infected with an unmodified DENV requires fixation and permeablization of cells to allow DENV-specific antibody staining. This method does not permit imaging of viable cells over time. In this report, a plasmid-based reporter was developed to allow non-destructive identification of DENV-infected cells. The plasmid-based reporter was demonstrated to be broadly applicable to the four DENV serotypes, including low-passaged strains, and was specifically cleaved by the viral protease with minimal interference on viral production. This study reveals the potential for this novel reporter system to advance the studies of virus–host interactions during DENV infection.