FIG 4.

Optimization of DENV2 and DENV4 VLP constructs. (A) VLP production levels of the prM-EF108A_2/1 construct with two different DENV2 strains. Expression vectors were transfected into 293F cells, and culture supernatants were tested for VLP production on day 4 by using a goat anti-DENV2 E polyclonal antibody. (B) Effects of prM E90D mutation on DENV4 VLP production. Culture supernatants were harvested at 4 days posttransfection and assessed by Western blotting using an anti-DENV4 E monoclonal antibody. Images representative of at least 3 independent experiments are shown.