Fig. 3

Overexpression of STING induces an antiviral immunity against a DNA virus.

EPC cells were transfected with 2 µg of pcDNA-STING, and pcDNA-MAVS or an empty vector (pcDNA) as positive and negative controls, respectively. At 48 h posttransfection, EPC cells were infected with a DNA virus of the Iridoviridae family, i.e., EHNV, at MOI of 1, 0.1 and 0.01 (A and C). The culture supernatants were collected at 0, 24, 48 and 72 h postinfection and the viral titer was determined by plaque assay on EPC cells (B and D). Cell monolayers were then stained with crystal violet either at 24 h postinfection (A) or 4 days postinfection (C) depending to the MOI used, as indicated. Each time point was represented by three independent experiments, and each virus titration was done in duplicate. Means are shown together with the standard errors. Asterisks indicate significant difference (*p<0.01 and **p<0.001) as determined by Student’s t test.