Figure 6.

Depletion of B cells results in a significant decrease of antitumor response in anti-CTLA-4 treatment. (A) Experimental protocol of treating human immune system mice with anti-CTLA-4 (200 µg, i.p.), anti-CD20 (300 µg, i.p.) or combination, starting post 15 days orthotropic cecum-implantation with 3 days interval. N=5 mice per group. All animals are sacrificed at the first observed endpoint (t=33 days) of control mice. (B) B cell (hCD20) population (percentage of hCD45⁺ cells) in cecum, liver, peritoneum, bone-marrow, and spleen samples, determined by flow cytometry. (C) Tumor/metastases area (hNucleoli mm² in cecum, liver, and peritoneum. Mann-Whitney: *p<0.05; **p<0.01; ***p<0.001; ****p<0.0001; ns, not significant. (D) Histological (hNucleoli) examples of liver metastases, scale-bar is 100 µm. CTLA-4, cytotoxic T-lymphocytes-associated protein 4; i.p., intraperitoneal.