FIG 2.

C. burnetii induces the expression of AMPs in S2 cells. (A to C) A luciferase reporter assay was performed to investigate the activation of the Drosocin (Dro) (A), CecropinA1 (CecA1) (B), and Defensin (Def) (C) AMP promoters in S2 cells following infection. At 24 h posttransfection, the cells were infected with C. burnetii (MOI = 100 GE/cell), and luciferase (luc) activity was assessed at different times postinfection. The firefly luciferase activity of each sample was normalized to Actin5C-driven Renilla luciferase activity to correct for transfection efficiency. (D to I) Drosophila S2 cells were infected with C. burnetii (MOI = 100 GE/cell), and total RNA was collected at 4 h and 24 h postinfection to examine AMP expression. Gene expression levels for Drosocin (D), CecropinA1 (E), Defensin (F), Diptericin (G), AttacinA (H), and Drosomycin (I) were determined by qRT-PCR. The relative expression of AMP was normalized to Drosophila RpII. The asterisks denote statistical significance (*, P < 0.05). The error bars indicate standard deviations.