Figure 1.

Increased Tc17 infiltration associates with shorter survival in PDAC. (A) Double immunostaining of PDAC tissue sections using antibodies against CD8α (green) and RORγt (brown), scale bar 100 µm. (B) Kaplan-Meier curve of overall survival (survival %) of patients with surgically resected PDAC showing≤6/mm² vs >6/mm² CD8⁺ RORγt⁺ cell infiltation (n=71, p values determined by log-rank test). (C) CD8⁺ RORγt⁺ cell frequency per mm² in T1/2 vs T3/T4 tumours (n=105), in tumours ≤4 cm vs >4 cm (n=105), No vs n+tumours (n=109) and UICC stage I/II vs III/IV (n=106). Box-plots depict the lower and upper adjacent values (whiskers) and the upper and lower quartiles (top and bottom edges of the box). Horizontal lines inside boxes indicate median, p values determined by Mann-Whitney U test. Each dot represents one individual. (D) Triple immunostaining of PDAC tissue for CD8α, IL-17A, and alpha−smooth muscle actin (αSMA). Left, PDAC tissue areas are denoted with single-positive IL-17A⁺ cells (brown), single-positive CD8⁺ cells (magenta), double-positive CD8⁺IL-17A⁺ (magenta-brown) and single-positive αSMA⁺ cells (green), scale bar 200 µm. Right, image magnification of cells highlighted in the left panel, scale bar 20 µm. (E) Kaplan-Meier curve of overall survival (survival %) of patients with surgically resected PDAC showing ≤5/mm² vs >5/mm² CD8⁺ IL-17A⁺ cell infiltration (n=71, p values determined by log-rank test). (F) Linear regression analysis of CD8⁺RORγt⁺ vs CD8⁺IL-17A⁺ cell frequencies in PDAC tissue. Linear regression line, Spearman’s correlation coefficient rho, and respective p value is shown in the plot (n=111). (G–I) Kaplan-Meier curves of overall survival (survival %) of patients with surgically resected PDAC showing ≤38/mm² vs >38/mm² single-positive CD8⁺ cell infiltration (G), intratumoural CD8⁺IL-17A⁺/CD8 ratios ⁺ ≤0.13 vs >0.13 (H) and intratumoural CD8⁺RORγt ⁺/CD8⁺ ratios ≤0.15 vs >0.15 (I) (n=71, p values determined by log-rank test). PDAC, pancreatic ductal adenocarcinoma.