Fig. 4

ZIKV induces astrocyte activation, but IL-22 plays a dispensable role in vitro. a Mouse primary astrocytes were infected by ZIKV with rIL-22 (200 ng/mL) added or omitted in vitro. Uninfected cells were used as a control. Cells were harvested at 24 and 48 hrs, followed by qRT-PCR analysis for astrocyte activation and (b) apoptosis/proliferation markers. In panel a, the fold changes of infected groups were normalized to those of uninfected controls. The asterisks in the ZIKV group indicate the results of statistical analysis between ZIKV and control groups. No significant difference was found for any marker between ZIKV and ZIKV+IL-22 groups. c Mouse primary astrocytes were infected by ZIKV with or without rIL-22 (200 ng/mL) and IFN-γ (100 ng/mL) in vitro. Viral loads were measured at 12 and 24 hrs. d Mouse primary microglia cells were infected by ZIKV with rIL-22 (200 ng/mL) added or omitted in vitro. Transcript levels of inflammatory cytokines and anti-apoptotic marker as well as viral burdens were examined by qPCR. All experiments were repeated twice independently. Data are shown as means ± SEM. Each group contains at least three samples, and one-way ANOVA was used to compare three groups. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, NS, not significant