Figure 5.

p53 Loss Increases Intratumoral and Systemic Suppressive Treg Cell Lineages

(A–E) Flow cytometry analysis of tumors from FVB mice injected with the isogenic cells lines KC1-p53^WT (black circles) and KC1-p53^KO (open circles) and analyzed 7 days post-injection. Cohort sizes n = 7–10, the means are represented as ±SEM.

(A) CD4⁺ T cell frequencies in the dLN from KC1-p53^WT KC1-p53^KO recipients.

(B) Intracellular staining of FOXP3 and CD4 surface expression in T cells within the dLN.

(C) The mean fluorescence intensity (MFI) of CD25 and GITR and the frequency of KLRG1 surface expression within Treg cell populations in tumor dLN.

(D) Frequencies of CD4⁺ T cell infiltration in KC1-p53^WT KC1-p53^KO tumors.

(E) Intracellular staining for FOXP3 in tumor-infiltrating CD4⁺T cells (left) and surface expression of KLRG1 within the CD4⁺FOXP3⁺ T cell population (right).

(F) Ex vivo Treg suppression assay of sorted CD4⁺CD25⁺ Treg cells from mice (cohort size n = 6) injected with KC1-p53^WT (black circles) and KC1-p53^KO (open circles) cell lines. Data show percentage of proliferating co-cultured CD4⁺CD25⁻ T cells that were stained with v450 proliferation dye. Each point represents CD4⁺CD25⁺ Treg cells from two pooled recipient FVB mice, and the means are represented as ±SEM.

An unpaired Student’s t test was used for statistics with p values of ^∗p < 0.05 and ^∗∗p < 0.01. See also Figure S5.