Figure 6.

GUCY2C-specific CAR T cells do not induce tissue damage. (A and B) MS24 CAR-T cells were administered to BALB/c mice with CT26.GUCY2C lung metastases established 14 d earlier following 5 Gy TBI. (A) Lungs, spleens, and intestines were collected 2 d later, and tissue sections were stained with anti-GUCY2C (red) and anti-GFP (green) antibodies and counterstained with DAPI. (B) GFP+ MS24 CAR-T cells were quantified in remnant follicles in spleen, tumor metastases in lungs, and Peyer's patches in intestines by immunostaining of GFP. Data represent the mean of four mice. (****p < 0.001, One-way ANOVA compared to accumulation in lung metastases). (C and D) BALB/c mice were treated with PBS, 5 Gy TBI, 5 Gy TBI + 1 × 10⁷ Control or MS24 CAR-T cells. On day 6 post-treatment, mice were sacrificed and tissues collected, fixed in formalin, and paraffin embedded. Slides were stained with H&E and scored for pathology. Scale bars indicate 100 μm. (C) Representative H&E-stained small intestine and colon sections. (D) Inflammatory scoring for all tissues collected. No significant differences between Control and MS24 CAR-T cell treatment groups were detected (One-way ANOVA).