Figure 4.

Tumor infiltrating tumor antigen-specific CD8⁺ T cells acquire an effector memory phenotype in ICT responding animals. Representative FACs plots comparing CD8⁺Thy1.1⁺ (blue) and CD8⁺Thy1.1⁻ (gray) T cell phenotype in post-treatment (A) DLNs and (B) tumors. Cells were analyzed for CD44, CD62L, CD127, KLRG1 and T-bet expression. Gates on the FACS plot represent effector memory (T_EM; CD44^hiCD62L^loCD127^hiKLRG1^hi) and effector (T_EFF; CD44^hiCD62L^loCD127^loKLRG1^lo) T cell subsets. Graphs representing frequencies of tumor antigen-specific (CD8⁺Thy1.1⁺) and endogenous (CD8⁺Thy1.1⁻) T cells that exhibit T_EM or T_EFF phenotypes in (C) DLNs and (D) tumors, grouped by response/non-response to ICT. (E) Representative histograms comparing CD127 and KLRG1 expression on activated (CD44^hiCD62L^lo) CD8⁺Thy1.1⁺ T cells between responding and non-responding DLNs (top) and tumors (bottom). (F) Median fluorescence intensity (MFI) expression of CD127 and KLRG1 on CD8⁺Thy1.1⁺ T cells in DLNs (top) and tumors (bottom) represented as dot plots. Data shown as mean ± SD. Mann-Whitney U tests were used to compare between both responders and non-responders, and between Thy1.1⁺ and Thy1.1⁻ T cells for each T cell phenotype; *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001.