Fig. 8.

Ad5-TA vaccinated mice had overall reduced portal, periportal and lobular hepatic inflammation as compared to unvaccinated mice, when challenged with toxin A. WT BALB/c mice were IM injected (10¹⁰ vp/mouse) with Ad5-Null or Ad5-C. difficile-TA. At 14 dpi mice were challenged with 300 ng (6 × LD₅₀ ) of purified toxin A (IP). At 14 dpi survivors from both groups were sacrificed, liver sections were stained with H&E and morphometric evaluation of these sections was performed as described in Section 2. (A) Representative sections from each treated animal were analyzed, scored and averaged for the levels of portal, periportal and lobular inflammation, as described in Section 2. The sum of averages for each category was computed to obtain a total inflammation index score. The error bars represent ±SD. Unvaccinated censored mice (n = 2) were used as positive control (high inflammation). Statistical analysis was completed using two-tailed Student’s t-test to compare 2 groups of virus-injected animals: Ad5-Null injected (n = 4) and Ad5-TA injected (n = 4). There was a trend of reduced inflammation in vaccinated mice, however, no significant differences was detected. (B) Representative liver sections for each group of mice are shown. Arrows indicate the following: (1) complete lobular disarray, with pooling of erythrocytes throughout the tissue subsequent to hemorrhage; (2) glassy eosinophilic hyalin deposition; (3) necrosis; (4) areas of cellular swelling indicating cell stress.