Fig 7.

Hepatic expression of selected cytokines and CD3 in woodchucks after two rounds of repeated injections with liver-nonpathogenic doses of WHV and subsequent challenge with a high, liver-pathogenic dose of WHV or injection with PBS. The levels of IFN-α, IFN-γ, TNF-α, IL-4, and CD3 mRNA were measured by real-time RT-PCR in liver tissue samples collected after the first round (n = 4) and second round (n = 4) of injections with 1.1 × 10² virions and then injected with PBS (n = 2) or rechallenged with 1.1 × 10⁶ virions (n = 2). The numbers (n) under each bar at the bottom of the figure indicate, respectively, the number of liver biopsy samples analyzed and the time of their collection, presented in weeks after the first injection of WHV in round 1 or round 2 or in weeks after rechallenge. The mean expression level of particular genes was normalized against β-actin expression and then compared with the mean determined in the liver samples collected prior to infection. Values marked with one asterisk were significant at a P value of ≤0.05, values with two asterisks were significant at a P value of ≤0.005, and values with three asterisks were significant at a P value of ≤0.0001.