Fig. 1

A129 mice 4-week-old survive to ZIKV PE243 and evoke a robust immune response. Three- and 4-week-old A129 mice were inoculated intravenously with 2 × 10⁵ PFU of ZIKV strain PE243. Uninfected mice were used as control. a, b Body weight gain (a) and lethality (b) of 3- (n = 9) or 4-week-old A129 mice (n = 15) infected with ZIKV PE243 were monitored for up to 15 days postinfection. c ZIKV RNA copies in the spleen, kidney, liver, and brain determined by qRT-PCR at days 3, 5, and 7 postinfection of 3- (n = 3–8) or 4-week-old mice (n = 4–6). Results are expressed as RNA equivalent/copies and normalized by GAPDH. Flow cytometry were performed on splenocytes from uninfected (n = 4–8) or 4-week-old mice at day 7 postinfection (n = 4–15). For cytokines and cytotoxic factors detection, splenocytes were restimulated in vitro with PMA and ionomycin in the presence of brefeldin A during 4 h. d Representative dot plot and frequency of CD62L⁻CD44⁺ (effector) among CD8⁺. e Representative counter plot and frequency of IFNγ, IL-2, CD107a, granzyme B (GrzmB), and perforin (Prfn) among CD8⁺ T cells. f Representative dot plot and frequency of CD62L^-CD44⁺ (effector) among CD4⁺. g Representative counter plot and frequency of I IFNγ, IL-4, and IL-17 among CD4⁺ T cells. h Representative counter plot and frequency of CD25⁺Foxp3⁺ or CXCR5⁺PD-1⁺ and CXCR5⁺PD-1⁺IFNγ⁺ among CD4⁺ T cells. i Representative counter plot and frequency of germinal center B cells among B220⁺CD138⁻ and plasma cells. Results are shown as mean in d–i or as mean ± standard deviation in a and c. Data are representative of two independent experiments in a, b, and c, data are presented as a pool of two or three independent experiments in d–i. Survival data were analyzed by log rank test. Data were analyzed by Student’s t test in c–i. * p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.001; **** p ≤ 0.0001