FIG 3.

Antiviral activity and IFN-I and -III mRNA induction by BV infection in human epithelial cells. (A) Characterization of cGAS and STING expression in HEK293 and HEK293 T cells by Western blotting. (B and C) HEK293 (B) or HEK293 T (C) cells were transfected with pTRIP-CMV-Puro-2A-cGAS (cGAS) or pcDNAhSTING (STING) and, after 48 h, infected with BV at an MOI of 100, 10, or 1. At 4 hpi, cells were infected with VSV at an MOI of 0.1. Sixteen hours later, VSV production was determined in Vero cells. (D and E) As indicated in the figure, some HEK293 cells were transfected only with poly(dA-dT) (1 μg/ml) or were pretreated with NU7026 (30 μM) for 16 h, and some HEK293 T cells were transfected with pTRIP-CMV-Puro-2A-cGAS (cGAS) or pcDNAhSTING (STING). After 48 h, cells were infected with BV at an MOI of 100, 10, or 1. After 4 h, RNA was extracted and RT-qPCR assays were performed. All the data from three independent experiments in biological triplicate were averaged and are shown as means ± SD. β actin was used as the housekeeping gene. The permutation test was used for comparisons of each treatment to untreated cells (indicated above each column: *, P < 0.05; **, P < 0.01; ***, P < 0.001). Statistical analyses among treatments were performed by a t test or one-way ANOVA followed by Bonferroni’s test (*, P < 0.05).