Figure 1. IFN-γ-deficient mice are highly susceptible to DENV infection.

(A) WT mice were inoculated with 10LD₅₀ of DENV-2 and at the indicated timepoints, the following parameters were assessed: IFN-γ concentration in serum (left panel) and spleen (right panel), measured by ELISA (A); IFN-γ intracellular staining in splenic cells, assessed by FACS analysis (B). (C–J) WT and IFN-γ^−/− mice were inoculated with 10LD₅₀ of DENV-2 and at the indicated timepoints, the following parameters were assessed: lethality rates after infection (C); platelet counts (D) and hematocrit (E) in blood; TNF-α (F) and IL-6 (G) concentration, measured by ELISA, and AST activity (H), measured by colorimetric assay, in serum; Liver injury, assessed by Hematoxylin & Eosin staining (five days after infection) (I); Viral loads recovered from the spleen, by plaque assay (J). Results are expressed as mean ± SEM (except for J, expressed as median) and are representative of at least two independent experiments. N = 5 mice per group * P<0.05 vs. NI. # P<0.05 vs. WT. NI: Not infected. ND: Not detected. dpi:day post-infection.