Fig. 6.

Role of immune subsets and gemcitabine in control of Pan02 growth. a Effect of depletion of the CD8⁺ T cells, CD4⁺ T cells, or NK cells in mice immunized with MVA-survivin and gemcitabine. C57BL/6 mice received s.c. injections of 2.5 × 10⁵ Pan02 cells. Gemcitabine (60 mg/kg) was injected i.p. on day 3. Mice were immunized twice i.p. with 5 × 10⁷ pfu of MVA-survivin. Mice treated with MVA-survivin with gemcitabine were i.p. injected with 200 μg of anti-CD8 mAb (H35) or anti-CD4 mAb (GK1.5), or anti-asialo GM1 (dilution 1/20) with a maintenance dose every 3 days until killing of the animals. b Effect of gemcitabine on susceptibility of Pan02 to cytotoxic T lymphocytes using chromium release assay. To generate effectors, Pan02-bearing C57BL6 mice (n = 3) were first immunized with MVA-survivin 3 days after tumor inoculation. Splenocytes were then harvested 1 week post-immunization and incubated for 1 week with irradiated Pan02 cells. These effectors were then incubated in 96-well plates (in triplicate) for 4 h with ⁵¹Cr-labeled Pan02 cells that had been treated overnight either in the presence or absence of 10 nM gemcitabine. *P < 0.05, Student’s t test