Figure 5. Effector/regulatory T cell ratios changes in favor of CD8 effector memory cells as a result of vaccination and HCT.

A, Experimental scheme. Syngeneic Thy 1.1 donors were vaccinated with 10⁶ irradiated CT26 cells and CpG. Bone marrow and splenocytes were transplanted into lethally irradiated Thy 1.2 hosts with s.c. tumors established for 14 days. Tumor-infiltrating cells and host spleens were analyzed d 14 after HCT (28 days after tumors were induced). Control tumor-bearing animals did not receive irradiation and HCT. B, Analysis of CD62L expression on CD8⁺ and CD4⁺ tumor-infiltrating T cells form irradiated hosts that received HCT (gated Thy1.1⁺ cells) or untreated control animals (no HCT)(gated Thy1.2⁺cells) at day 28. The data are representative for the group of animals (n=5).

C–D, CD25 expression of tumor-infiltration CD4+ T cells and analysis of CD4⁺CD25⁺Foxp3⁺ T cells in tumors obtained from untreated animals on day 14, untreated animals on day 28 as well as tumor-bearing animals that received HCT (day 28). Mean percentages and SE are shown (n=5 in each group). E, CD8⁺ effector memory/Treg ratio in tumors in animals receiving HCT versus untreated animals on day 28. Mean percentages and SE are shown (n=5 in each group) (p<0.05).