Figure 3. 4T1-specific IFNγ-producing cells are induced in untreated and CY+TLRa-treated 4T1 TB mice, giving rise to immunological memory.
A.-B. Purified CD8+ T-cells from LN of naïve (non-TB), untreated TB, and CY+CpG-treated TB mice were evaluated for IFNγ production by ELISpot. Samples were studied at d28 of 4T1 tumor challenge, comparing untreated mice vs CY+CpG-treated mice at c2d3. A. Enriched CD8+ T-cells (1×105 cells per well) were cultured in the presence or absence of irradiated 4T1 or BM185 tumor cell lines (1×105 cells per well) for 48h. IFNγ production was analyzed as number of IFNγ spots per 1×105 enriched CD8+ T-cells. Data are expressed as means ± SD, obtained from three independent biological experiments with three replicates per group. Statistical analysis was performed using one-way ANOVA with Tukey's posttest (*p < 0.05; **p < 0.01, ***p < 0.001). B. Representative ELISpot wells for naïve “N”, untreated 4T1 TB “U” and CY+CpG-treated 4T1 TB “T” mice. C. Long-term tumor-free CY+CpG-treated mice were rechallenged s.c. with 1×106 4T1 viable tumor cells. Mice displaying progression of the 4T1 rechallenge were again treated with CY+CpG for 7 cycles. Each line represents a single mouse (n = 6), plotted to show primary tumor size vs day post tumor challenge. D. 4T1 growth in challenged naïve mice vs rechallenged long-term tumor-free mice. Data correspond to 10 mice per group. Representative data from two independent biological experiments with similar results. Data are expressed as means ± SD. Statistical comparisons were performed using Student's t-Test.