Fig. 5

M1-like colonic macrophages and their factors IL-1β and TNF-α contribute to PD-1/PD-L1 inhibitor-related cardiotoxicity. In the B16F10 melanoma model, the mice were intraperitoneally administered with the PD-1/PD-L1 inhibitor BMS-1 (0, 5 and 10 mg/kg) every 2 days for 6 times (n = 10). A-C Representative images of immunostaining analysis of CD68⁺iNOS⁺ and CD68⁺CD206⁺ cells in colonic tissues and corresponding quantitative analysis. Scale bars, 20 μm. D M1 marker (iNOS and CXCL9) and M2 marker (CD206 and Arg-1) in colonic macrophages were measured by qPCR. E The production of M1 factors (IL-1β and TNF-α) and M2 factors (TGF-β and IL-10) in colonic macrophages were determined by ELISA. F In the B16F10 melanoma model, the mice were administrated intraperitoneally with 50 mg/kg anti-CSF-1 antibody 24 h before BMS-1 (10 mg/kg) injection, and followed by repeated injections of 25 mg/kg every 5 d to deplete colonic macrophages (n = 10). G The serum levels of creatine kinase-MB (CK-MB), aspartate transaminase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH). H Representative images of TUNEL assay of cardiac tissues and corresponding quantification analysis. Scale bars, 50 μm. I In the B16F10 melanoma model, the mice were administrated intraperitoneally with anti-IL-1β antibody (100 μg), anti-TNF-α antibody (100 μg) or their combination (IgG as control) every 2 days for 3 times during BMS-1 (10 mg/kg) injection (n = 10). J Representative images of Masson staining of cardiac tissues and corresponding quantification analysis. Scale bars, 20 μm. K Representative images of TUNEL assay of cardiac tissues and corresponding quantification analysis. Scale bars, 50 μm. The values are presented as the mean ± standard error of the mean. ^*P < 0.05, ^**P < 0.01 vs. control or BMS-1 or IgG, ^#P < 0.05, ^##P < 0.01 vs. anti-TNF-α