Figure 6.

Rectal adenoviral vector encoding murine interleukin 10 (AdvmuIL-10) induced a diminished antiadenoviral response in IL-10−/− mice. The neutralising antiadenovirus antibody titre was analysed in serum from (A) IL-10−/− and (B) wild-type mice four weeks after rectal instillation of 5×10⁸ PFU of AdvmuIL-10, empty cassette adenoviral vector (Adv0), or saline vehicle. Serial serum dilutions were incubated for 90 minutes at 37°C with 2×10⁶ PFU of adenoviral vector encoding β-galactosidase (Advβgal) and applied in duplicate to 80% confluent 293 cells on a 96 well plate. After one hour at 37°C, 50 μl of Dulbecco’s modified Eagle’s medium containing 10% fetal calf serum was added to each well, and cells were cultured for a further 36 hours. Cell supernatants were then removed and assayed using a β-galactosidase substrate solution. In this assay, a low optical density reflects a high titre of serum antiadenoviral antibodies. Results are expressed as mean (SEM) optical density for each group. ***p<0.001 compared with saline treated mice, two way ANOVA).