CD8+ T cells from tumor-bearing mice have impaired antitumor effector function as compared with CD8 T cells harvested from tumor-free mice. A/J mice were inoculated subcutaneously with 105 live AGN2a cells (tumor-bearing) or PBS (tumor-free) in the hind flank. Vaccinated (Presensitized) mice were given 2 × 106 irradiated AGN2a-4P vaccine cells on days 0 and 7, as shown at the top of Figure 1. Five days after the second vaccination (day 12), spleens were harvested for in vitro analyses. (A) Splenic CD8+ T cells were purified by immunomagnetic cell sorting, and examined in IFN-γ ELISPOT assays using live AGN2a cells as stimulators. Shown is a representative of 2 independent experiments in which the CD8 T cells were pooled from 3-5 individual mice. ***P < .001 when tumor-bearing results were compared with tumor-free results. (B) CD8+ splenocytes were analyzed for expression of CD44, CD49b, and L-selectin by flow cytometry. Data are representative of at least 3 separate experiments.
