Figure 2. IFN Induction in Draining Lymph Nodes and Serum of Mice Infected with WNV.
(A, B) Mice were inoculated with 102 PFU of WNV by footpad injection and euthanized at the indicated times. Total RNA from draining lymph was analyzed for (A) IFN-α and (B) IFN-β mRNA expression by qRT-PCR. Data are normalized to 18S rRNA and are expressed as the relative fold increase over normalized RNA from uninfected controls. Average values are from five to 12 mice per time point, and error bars indicate the SD. Asterisks indicate differences that are statistically significant (*, p < 0.05).
(C) IFN activity was determined from serum collected on days 1 to 4 after infection by an EMCV bioassay in L929 cells. Data reflect the average of serum samples harvested from five to ten mice per time point and are shown as the percentage of cells protected from lysis by EMCV (see Materials and Methods). Asterisks indicate differences that are statistically significant (*, p < 0.05; ***, p < 0.0001).