Figure 2

DENV infection causes minor effects on cell growth but considerably changes microglial cell morphology. (A) MTT and (B) LDH assays showed the cell viability and cytotoxicity, respectively, of BV2 cells inoculated with different MOIs of DENV 2 for the indicated different times. The quantitative data (optical density, O.D.) are shown as the means ± SD from three independent experiments. ns, not significant. The cells were inoculated with DENV 2 (MOI = 50) (C) without or (D) with Alexa-594 labeling (red). At 6 h post-infection, time-lapse microscopy showed changes in cell morphology characterized as round, spindle, and multipolar. The percentages of cells with morphological changes were determined and quantified as the means ± SD of three independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001. (E) Confocal microscopy showed actin polymerization (green) after DENV infection as detected by viral E protein expression (red). (F) Representative confocal fluorescent immunostaining of Iba-1 (green) in DENV-infected brains. Dotted lines indicate the hippocampal region. For all images, representative data were selectively obtained from three individual experiments. DAPI staining indicated the nuclei (blue).