Figure 4.

After 59 days of PDV tumor growth, rosiglitazone treatment continues to promote tumor infiltration of CD3⁺ cells but also suppresses a late increase in CD11b⁺Gr-1⁺ myeloid cells. After 59 days of tumor growth, mice were euthanized and vehicle (VEH) treated PDV tumors and the surviving rosiglitazone (Rosig)-treated PDV tumors were excised. (A–C.) Rosig treatments promotes tumor infiltrating CD3⁺ T-cells. Formalin-fixed paraffin-embedded (FFPE) tumor sections were labeled by immunofluorescence with anti-CD3 antibodies and anti-pan-CK antibodies. Tissues cytometry was then performed as detailed in Figure 3. Total infiltrating CD3⁺ T-cells, intra-tumoral CD3⁺ T-cells, and peri-tumoral CD3⁺ T-cells are shown. Rosig treatment resulted in a significant increase in CD3 cells relative to all cells in the tumor (A) and in intra-tumoral CD3⁺ cells (B) (n = 7 for VEH and n = 7 for Rosig treated groups, 2-tailed t-test). (D–F) PDV tumors obtained from mice treated with Rosig show a significant reduction in CD11b⁺Gr-1⁺myeloid cells, but no significant reduction in myeloid cells expressing only CD11b or only Gr-1. FFPE tumor sections were labeled by immunofluorescence with anti-CD11b and anti-Gr-1 as in Figure 3. Tissue cytometry was then performed to quantitate cells labeled with both CD11b and Gr-1 (CD11b⁺Gr-1⁺), CD11b alone (CD11b⁺) or Gr-1 alone (Gr-1⁺). Rosig treatment significantly decreased the numbers of myeloid cells co-expressing both CD11b and Gr-1 (D), but had no significant effect on myeloid cells expressing only CD11b (E) or Gr-1 (F) (n = 6 for VEH treated and n = 5 for Rosig treated groups, 2-tailed t-test). * p < 0.05; ns = non-significant.