Figure 1.

Mechanisms of radiation therapy and immunity (abscopal effect) [29].

TAAs are released by radiation to a tumor. After that, TAAs are captured by APCs, such as macrophages and dendritic cells. DAMPs and pro-inflammatory cytokines (IFN-I) are released by radiation to a tumor. DAMPs and pro-inflammatory cytokines lead to maturation and activation of dendritic cells. Radiotherapy results in upregulation of PD-L1 and MHC class I on tumor cells. APCs migrate to lymph nodes to present TAAs to cytotoxic T cells. Activated T cells induce immunogenic tumor cell death by acting on the primary irradiated tumor, as well as distant metastatic sites.