Fig. 2.

Antibodies targeting CD25 and CTLA-4 induce CD4⁺ T cell infiltration into spontaneous PDAC tumors. Mice (n = 4/group) were treated with: a anti-CD25 (day 1) versus isotype control (day 1) or b anti-CTLA-4 (days 1, 4, 8, 11), or isotype control (days 1, 4, 8, 11). Shown is the impact of treatment with: a anti-CD25 (black) versus control (gray) and b anti-CTLA-4 (black) versus control (gray) on the frequency of CD3⁺CD4⁺Foxp3⁺ Tregs and CD3⁺CD4⁺Foxp3^neg conventional T cells detected in the peripheral blood after treatment. Shown is: c quantification per high power field (hpf) and d representative images of immunohistochemistry to detect CD3, CD8, CD4 and Foxp3 cells in PDAC tumors from KPC mice at 14 ± 2 days after beginning treatment with anti-CD25 (n = 5) or anti-CTLA-4 (n = 5) with comparison to isotype control (n = 4). Scale at 40× magnification