Fig. 7. ZIKV infection of α-IFNAR-treated C57BL/6 mice promotes bystander activation independent of viral load.

C57BL/6 mice were treated with α-IFNAR antibody at −1, 0, 1, 3, 5 dpi and infected via FTPD with 1.4 × 10⁶ ZIKV PFU. Ifnar^-/- mice were infected via FTPD with 4 × 10⁵ ZIKV PFU. a Viral titer in the serum at 3 dpi (n =4, 5). b Spleen cells were isolated for flow cytometry at 8 dpi and CD45⁺ cells were assessed for % CD8⁺NKG2D⁺ T cells (n =4, 5). c Spleen CD8⁺ T cells were assessed for %NKG2D⁺ or D) NKG2D MFI (n =4, 5). e At 8 dpi, spleen CD8⁺ T cells were isolated via negative selection. A cytotoxicity assay was performed by incubating CFSE-labeled YAC-1 cells with spleen CD8⁺ T cells at various effector:target (E:T) ratios (n =4, 5). Each datapoint represents the mean of technical duplicates. f Weight loss at a % of D0 starting weight (n =4, 5). g Mice were assessed for clinical symptoms of paralysis at 8 dpi (n =8, 14; data represent two independent experiments). h Quantification of clinical scores in g (n =8, 14). i Representative flow cytometry plots of brains of ZIKV-infected Ifnar^-/- and α-IFNAR-treated C57BL/6 mice. j Quantification of i (n =4, 5). k Counts of immune cell populations from i (n =4, 5). l Counts of CD8⁺ and m CD8⁺NKG2D⁺ in ZIKV-infected Ifnar^-/- and α-IFNAR-treated C57BL/6 mice (n =4, 5). Data represents mean ± SEM (a–f, h, j–m) of one of two independent experiments with similar results. Statistical significance was determined by two-tailed Student’s t test (a–d, h, l, m) or repeated measures (f) or ordinary (e, j, k) two-way ANOVA with Sidak’s multiple comparisons test. MFI = mean fluorescence intensity. Source data are provided as a Source Data file.