Fig. 5

ZIKV infection induces the splicing of xbp1 and the translocation of XBP1s into the nuclei of human neural cells. a, b CCF- STTG1 and SK-N-SH were infected with ZIKV at an MOI of 5 PFU/cell. Positive control (Tm) was treated with 2 μM tunicamycin. RNA was extracted at 24 and 48 hpi and the first strand cDNA was synthesized. Primers that specifically amplified xbp1s and total xbp1 (including both xbp1u and xbp1s) were used to analyze xbp1s via RT-qPCR. The relative expression levels of the xbp1s and t-xbp1 were calculated according to the 2^−∆∆Ct method. The ratios of xbp1s/t-xbp1 between mock-infected and ZIKV-infected were calculated. Data represented three independent experiments and error bars indicate mean ± SD. Statistical analyses were performed using multiple t tests (N = 3) (P < 0.05 or P < 0.01). c, d CCF- STTG1 and SK-N-SH were infected with ZIKV at an MOI of 5 PFU/cell and fixed at 24 hpi at which time xbp1 starts to be spliced. Cells were stained with Goat anti-Rabbit IgG secondary antibody, FITC (green) against anti-XBP1 antibody (recognizing both non-spliced and spliced isoforms of XBP1) and Goat anti-Mouse IgG secondary antibody, Texas Red®-X (red) against anti-ZIKV envelope protein antibody. Cell nucleus was visualized using Hoechst 33258 (blue). Positive control (Tm) was treated with 2 μM tunicamycin. The results represent three independent experiments and one of three experiments is shown. e Positive rates of nuclear localization were counted. Data represent three independent experiments and error bars indicate mean ± SD. Statistical analyses were performed using multiple t tests (N = 3) (P < 0.05 or P < 0.01)