Figure 2. DMAb results in long-term expression of neutralizing DENV antibodies in mouse serum.

(a) Total serum-detectable levels of human IgG was measured by ELISA after a single intramuscular injection of DNA plasmid encoding the anti-DENV human IgG antibody DVSF-1 into Foxn1/NuJ immunodeficient mice. Human IgG levels between weeks 0–4 (left; data displayed are mean of duplicate values each animal +/−SEM) and at week 19 (right; error bars display the mean of duplicate values from five animals +/− SEM). Each line (left) or dot (right) represents an individual mouse (n = 5 mice). (b) Total human IgG in serum was measured by ELISA after intramuscular injection of pDVSF-3 WT or pDVSF-3 LALA plasmids in 129/Sv mice (n = 4–5 mice per group, data displayed are the mean +/− SEM of each group’s animals and are representative of two independent experiments). (c) Vero cells were either uninfected (Mock) or infected by DENV1, 2, 3, or 4, then fixed, permeabilized, and stained with 129/Sv mouse serum taken at days 0 or 7 post-DNA injection of either pDVSF-3 WT, pDVSF-3 LALA or pVax empty vector (n = 5 mice per group, data representative of two independent experiments).(d) Neutralization was assessed by incubating DENV1, 2, 3, or 4 with serial dilutions of 129/Sv mouse serum taken at day 7 post-DNA injection of either pDVSF-3 WT or pDVSF-3 LALA (n = 5 mice per group) before addition to Vero cells. The percentage of infected cells is shown; error bars are the mean +/− SEM of each group’s animals).