Figures & data
Figure 1. Immunologic microenvironment of CRC may dictate the sensitivity to checkpoint blockade. (A) The high density of mutations in MSI CRC increases the number of neoepitopes presented by tumor cells to tumor-infiltrating immune cells. Activation of the immune effector cells (CTL in the figure) is associated with the production of inflammatory mediators, including IFNγ which induces the upregulation of checkpoint ligands in the TME (on tumor cells in the figure). The recognition of neoepitopes by T cells and the nature of the checkpoints expressed in the TME will drive the sensitivity of the tumor to checkpoint blockade and will guide the nature of the inhibitors to be used. (B) Despite displaying a low density of mutations, some MSS CRC, present neoepitopes and are capable of activating specific immune responses. The frequency of such immunogenic MSS is yet unknown. The aforementioned immunogenic MSS CRC should be also eligible for the immune checkpoint blockade. (C) Most of the MSS CRC are poorly immunogenic and do not qualify for immune checkpoint blockade as a therapeutic approach.
