Figure 1.

The immunization and sample collection schedule, and in vitro and in vivo expression of the prM-E proteins. (A) Diagram of immunization, sample collection and challenge in BALB/c mice. The mice were vaccinated at weeks 0, 3, and 6. Splenocytes and muscle tissues were obtained at the seventh week, and sera were collected at the ninth week, the sixth month, and the 12th month. The mice were challenged with DENVs at the ninth week and the 12th month. (B) In vitro expression of the prM-E proteins in plasmid-transfected Vero cells detected by IFA. DENV3-infected Vero cells served as the positive control. (C) The cell lysate and the supernatant of plasmid-transfected Vero cells were collected at 72 h after transfection and in vitro expression of the E protein was detected by Western blotting. DENV3-infected Vero cells served as the positive control. GAPDH served as the loading control. (D) In vivo expression of the prM-E protein at the injection site in muscle tissues detected by IHC.