Figure 6. Phenotype of macrophages that regulate T cell immunosurveillance in spontaneous pancreatic carcinoma.

(A) Immunofluorescence images (with high magnification insets) showing DiI-liposome (red) uptake within (i) spleen, (ii) peritumoral lymph node, and (iii) tumor in a KPC mouse 24 hours after intraperitoneal injection of DiI-liposomes. Nuclei are stained with DAPI (blue). Scale bars, 20 μm. (B) A representative lymph node adjacent to tumor showing (i) F4/80⁺ macrophages (green), (ii) DiI-liposomes (red), and (iii) merged images revealing DiI-liposome uptake by F4/80⁺ macrophages. Scale bars, 20 μm. (C) Uptake of DiI liposomes by myeloid cells expressing F4/80, Ly6C, and Ly6G markers versus CD3⁺ T cells was quantified in KPC mice by flow cytometry. Gating strategy is shown in Supplementary Figure 8. *P<0.05, Student's t test. (D) Mean fluorescence intensity (MFI) for surface molecules present on CD45⁺ CD3^neg CD11b⁺ Ly6G^neg F4/80⁺ Ly6C^low cells in KPC (blue) vs control (white) mice. *P<0.05, **P<0.005, Student's t test.