FIG 5.

ORF3a-induced apoptosis by natural and artificial mutant variants correlate with cellular oxidative stress and innate immune proinflammatory responses. 293T cells were transfected with plasmids harboring ORF3a wild type (WT), ΔG188, or Q57H mutant variant. Effects of ORF3a mutant variants on cytopathic effects (A), as measured by cellular growth (a), cell viability (b), and cell death (c), at the indicated times. (B) Effects of ORF3a mutant variants on apoptosis (a) and necrosis (b). (C) Induction of oxidative stress. The images were taken at 72 hpt. Scale bar = 20 μM. (D) ORF3a elevates NF-κB-mediated transcriptional activities. (E) Activation of cellular innate immune proinflammatory responses, as measured by qRT-PCR. Data are presented as mean ± SE from three independent experiments. Statistical differences between control and ORF3a WT or mutants (indicated with #) or between WT and mutants (indicated with *) were evaluated. * or #, P < 0.05; ** or ##, P < 0.01; *** or ###, P < 0.001 (one-way ANOVA).