Fig. 6: CTR9 is required for immune evasion in PDAC.

a Box plots showing the percentage of the indicated cells (left), or intensity of DAB (diaminobenzidine) staining (right) in tumor tissue. Mice carrying tumors expressing doxycycline-inducible shRNA against Ctr9 were treated for three days with doxycycline or control. For each plot, 4–6 regions per tumor were evaluated from three independent tumors, n = 14 regions analyzed. P values were calculated using unpaired two-tailed t-test using Welch’s correction. In the box plot, the central line shows the median, the box borders extend from the 25th to the 75th percentile, and the whiskers go down to the smallest value and up to the largest. b Bar plots showing flow cytometry analysis of immune cell subsets in the tissues of tumors initiated by orthotopic transplantation of KPC cells harboring doxycycline-inducible shNTC or shCTR9. After 7 days of transplantation, doxycycline treatment was added for 3 days. Pre-gating was performed using single living cells. cDC1 cells were defined as (CD45⁺, CD11b⁻, CD11c⁺). Data are presented as mean ± s.d. (n = 6 independent tumors; unpaired two-sided t-test). c Left, bar plots showing the percentage of CTLA4⁺ T-cells of CD3e⁺ or CD8⁺ cells, data are presented as mean ± s.d. (n = 6 independent tumors; unpaired two-sided t-test). Middle, histograms showing staining of CTLA4 on T-cells (CD3e⁺), with intensity on the x-axis, and counts on the y-axis. Right, flow cytometry contour plot, documenting the gating strategy for CTLA4⁺ T-cells (CD3e⁺). d Representative immunohistochemistry images of tumor sections stained for CD8 (brown) with two different magnifications. Note the juxtaposition of CD8-positive T-cells with the remaining tumor cells. “-CTR9” refers to three days of doxycycline treatment. e Luciferase imaging of KPC cell derived tumors harboring shRNA against Ctr9 upon orthotopic transplantation into NRG mice. Doxycycline treatment was started 7 days after transplantation. Luciferase activity of KPC cells was measured at day 7 after transplantation (start) and after 1 and 2 weeks of doxycycline treatment. f Kaplan–Meier plot of NRG mice transplanted with KPC cells expressing doxycycline-inducible shCTR9. shRNA was induced with doxycycline from day 7. P values were calculated using two-sided Mantel–Cox test. Source data are provided as a Source Data file.