Fig. 7

Administered mC4BPA peptide reaches PDAC stroma and functions in vivo. a The mC4BPA peptide, which is composed of 30 amino acids from the C-terminus of mC4BPA, was conjugated with Cyanine 5 (Cy5) at the N-terminus. b Experimental design of the randomized trial using PKCY cells in the orthotopic transplantation model. Mouse IgG2a antibody (Control); Gem and nab-paclitaxel (GnP); the combination of GnP and ICBs; and the combination of GnP, ICBs, and mC4BPA peptide were administered by intraperitoneal injection. c-h Immunofluorescence staining for representative pancreatic tumors in orthotopic transplantation models. (c, d) Immunofluorescence staining for DAPI, YFP, and mC4BPA in the GnP group; (e, f) for DAPI, YFP, mC4BPA, and CD8 in the GnP group; and (g, h) for DAPI, YFP, Cy5 (mC4BPA peptide) in the GnP/ICBs/mC4BPA peptide group. Yellow arrows show binding of the respective, fluorescence dye-labeled antibodies. Bar, 50 μm. i Number of CD8⁺ T cells counting in 2 different HPFs per mouse are depicted for treatment groups in box-plot histograms. (Control vs. GnP: P=0.43, Control vs. GnP/ICBs/mC4BPA peptide: *P=0.042, GnP vs. GnP/ICBs/mC4BPA peptide: P=0.14, Mann–Whitney–Wilcoxon test). j Waterfall plot indicating percent change in tumor volume after therapy compared with the tumor volume at baseline. (Control vs. GnP: P=0.12, Control vs. GnP/ICBs/mC4BPA peptide: *P=0.0034, GnP vs. GnP/ICBs/mC4BPA peptide: P=0.079, chi-square test). Each volume represents the mean ± SEM in the below box.