Fig. 3

Lymphocytes and IFNγ signaling are required in the resistance to ZIKV PE243. Four-week-old A129 or AG129 mice were inoculated intravenously with 2 × 10⁵ PFU of ZIKV PE243. a Body weight gain and b lethality of A129 mice previously depleted of CD8⁺ (n = 4), CD4⁺ T cells (n = 9), or B cells (n = 9) infected, and monitored for up to 15 days postinfection. Control mice received IgG2a isotype control (n = 10). c Body weight gain and d lethality of infected AG129 mice (n = 11) compared to A129 mice (n = 10). e ZIKV RNA copies in the spleen, kidney, liver, and brain postinfection of A129 (n = 4–6) or AG129 mice (n = 3–4), and infectious particles of ZIKV in the spleen and brain at 7 days postinfection, determined, respectively, by qRT-PCR and plaque assay. The horizontal dotted line indicates the limit of detection. f Representative photomicrographs of DAB-stained (Scale bar: 200 μm) or IgG-stained (Scale bar: 500 μm) brain sections retrieved from uninfected AG129 mice (n = 3) or AG129 mice at day 7 postinfection with ZIKV PE243 (n = 3). The arrow points to a focus of microhemorrhage in the white matter while IgG stains in brown. g Frequency of effector CD8⁺ T cells or CD4⁺ T cells, CD4⁺CXCR5⁺PD-1⁺ cells, germinal center B cells and plasma cells in the spleen of infected AG129 mice (n = 8) at day 7 postinfection, compared to uninfected AG129 mice (n = 5–6). Results are shown as mean in g and e or as mean ± standard deviation in a, c, and e. Data are presented as a pool of two (a, b, and g) or three (c and d) independent experiments, experiments were performed once in e and f. Survival data were analyzed by log rank test. Data were analyzed by Student’s t test in e and g. (*) p ≤ 0.05; (**) p ≤ 0.01; (***) p ≤ 0.001; (****) p ≤ 0.0001; ns not significant; Hypo hypothalamus; hipp hippocampus