Figure 4. Functional significance of T regulatory cells in NSCLC.

(A) Frequency of Foxp3⁺ T_reg cells within the CD4⁺ T cell compartment in human NSCLC assessed by flow cytometry, with representative FoxP3 immunohistochemistry shown on left. n=6 per group. (B) Frequency of Foxp3⁺ Treg cells within the CD4⁺ T cell compartment in CC10-TAg tumors at various ages as assessed by flow cytometry, with representative FoxP3 immunohistochemistry shown on left. n=5∓8 mice per group. (C) Percent of CD3⁺CD4⁺FoxP3⁺ cells expressing CD103⁺ in CC10-TAg tumors. n=5∓8 mice per group. (D) T_reg depletion was assessed in CC10-TAg mice in a prevention trial by IP injections of αCD25 mAb every 5 days from 4 weeks until 8 weeks of age. (E) Frequency of Foxp3⁺ T_regs represented as percentage of CD3⁺CD4⁺ T cells in spleen (left) and lung tumors (right) following treatment with αCD25 mAb. (F) Tumor burden represented as percentage of lung area following αCD25 treatment in CC10-TAg mice. (G) Number of BrdU⁺ tumor cells per square millimeter of lung tumors. (H) Angiogenic vasculature represented as percent positive pixels of CD31 staining by automated quantification of representative stained sections. (I) Number of cleaved caspase 3⁺ tumor cells per square millimeter of lung tumors. (J) Immune cell complexity of lung tumors following T_reg depletion represented as percentage of CD45⁺ leukocytes assessed by flow cytometry. (K) CD8⁺ T cell infiltrate of lung tumors as assessed by flow cytometry, shown as a percent of total CD45⁺ cells. (L) Absolute numbers of CD8⁺ cells per square millimeter of lung tumor with representative immunohistochemistry shown to the right. (E-L) n=12∓13 mice per group with data obtained over 3 independent cohorts of animals. *p<0.05; **p<0.01, ***p<0.001.