Fig 2: Histopathological examination of specimens collected from mice. (A) Tissues from orthotopic mouse models treated with anti-CEA-CAR-T or non-modified T cells on day 21 were stained with hematoxylin and eosin and analyzed for CD4, CD8, CK, and CEA expression by antibody staining. (B) Counts of CD8+ T cells infiltrating into the center and peritumor area within the range of 0.25 mm2/field.

Fig 3: Immunohistochemical staining for CEA in PDAC patients. (A) CEA staining intensity was categorized into three grades. (B) Heterogeneity was classified into five grades. (C) Analysis of correlation between serum CEA and staining intensity of cell membrane CEA. There was no significant correlation.

Fig 4: In vitro functional assays: ELISA. (A) Quantitative measurement of IFN-γ in cell supernatant after co-culture with CAR-T. (B) The secretion levels of IFN-γ were correlated with the number of CEA molecules. ※ p < 0.05.

Fig 5: In vivo antigen quantification. (A) Immunofluorescence microscopy was used to detect CEA expression on cell membranes in cell lines. (B) Western blot analysis of whole-cell lysates using the indicated antibody detected the 180 kDa CEA, or anti-βactin antibody as the internal control. (C) Flow cytometry of each cell line tested qualitatively and quantitatively for CEA expression. For each graph, the red curve corresponds to cells, primary anti-CEA antibody, and secondary Alexa Fluor 488 conjugated antibody; the blue curve represents cells and isotype control.