Figure 2.

Passive NS1 immunity in AG129 ADE infection model. (A) AG129 mice born to DENV1-immune mothers were passively transferred with NS1 immune serum collected from NS1(16681)-immunized A129 mice (Fig. 1 A) or with naive serum. 1 d after transfer, the mice were challenged s.c. with 10³ PFU D2Y98P. (B and C) Systemic sNS1 level) and viremia titers (C) were measured at days 2, 4, and 6 p.i. (n = 4–5). (D and E) Mice (n = 8) were monitored daily upon challenge. Kaplan–Meier survival curve and clinical score are shown. (F) Vascular leakage was assessed in indicated tissues at day 6 p.i. (n = 4–5). Data are representative of at least two independent experiments. Data were analyzed by nonparametric Mann–Whitney U test. *, P < 0.05; **, P < 0.01; ns, not significant. Results were expressed as averages ± SD (B and F).