Figure 1.

HFRT induces significant alterations of MDSCs and T cells within tumors

(A) Treatment scheme. (B) Bar plots showing fractions of CD45⁺ tumor-infiltrating immune cells (TIICs), CD11c⁺ DCs, CD49b⁺ NK cells, CD11b⁺ F4/80⁺ macrophages, or CD4⁺ CD25⁺ Foxp3⁺ Treg cells in CT26 tumors. (C and E) Representative flow plots of CD45⁺ TIICs, CD3⁺, CD4⁺, CD8⁺ T cells, Gr-1⁺ CD11b⁺ MDSCs, Gr-1⁺ CD11b⁺ Ly6G^high polymorphonuclear (PMN)-MDSCs, or Gr-1⁺ CD11b⁺ Ly6G^low M-MDSCs in CT26 tumors (percentage of all live cells) in tumor. (D and F) Bar plots showing fractions of total MDSCs, PMN-MDSCs, M-MDSCs, CD3⁺, CD4⁺, or CD8⁺ T cells (percentage of all live cells) in CT26 tumor. (G) Representative multicolor immunofluorescence images of tumor specimens from rectal cancer patients who received 5 × 5 Gy preoperative HFRT (n = 3; scale bar: 100 μm; magnification 20×; MDSCs: red arrowheads, T cells: white arrowheads). (H–K) Bar plots showing fractions of CD45⁺ TIICs, CD3⁺, CD4⁺, CD8⁺ T cells, MDSCs, PMN-MDSCs, and M-MDSCs (percentage of all live cells) in 4T1 (H and J) or MC38 (I and K) tumor. The results are presented as mean ± SEM. ∗p < 0.05 and ∗∗p < 0.01; NS, p > 0.05 (unpaired Student’s t test).