Cell microparticles loaded with tumor antigen and resiquimod reprogram tumor-associated macrophages and promote stem-like CD8+ T cells to boost anti-PD-1 therapy

Tumor microenvironment profoundly affects the therapeutic efficacy of ICB. In view of the fact that inbred mouse strains bearing monoclonal cancer cell line-derived tumors respond in a dichotomous manner to ICB, to gain insight into the mechanisms of ICB resistance in HCC, the anti-PD-1 antibody-responsive and nonresponsive mice were used for analyzing the difference in gene expression using bulk RNA sequencing (RNA-seq). The orthotopic Hepa1-6 tumor-bearing mice were intraperitoneally injected with anti-PD-1 antibody or PBS every four days for five times and then the three PBS-treated tumors, anti-PD-1-treated three smallest tumors (deemed as anti-PD-1 antibody-responsive tumors) and the anti-PD-1-treated three largest tumors (deemed as anti-PD-1 antibody-nonresponsive) were used for analyzing the difference in gene expression using bulk RNA sequencing (RNA-seq).