Figure 1.

Synergistic effect of immunogenic chemotherapies and immune checkpoint inhibitors. Cisplatin (CDDP) is a non-immunogenic cell death (ICD)-inducing chemotherapeutic that fails to prime adaptive immunity in tumors, forming a “cold” immune microenvironment that consists more immune suppressive cells like tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDCSs), and regulatory T cells (Tregs), but less antigen presenting cells such as dendritic cells (DCs) or effector cells such as cytotoxic T lymphocytes (CTLs). Thus, CDDP cannot synergize with PD-1 targeting immune checkpoint inhibitors (ICIs). Oxaliplatin (OXA) induces ICD and establishes a primed “hot” tumor immune microenvironment that favors the infiltration and accumulation of DCs and CTLs over immunosuppressive cells, thus sensitizing to the immunotherapeutic effects of PD-1 targeting antibodies.