Deciphering Mechanisms of UVR-Induced Tumoral Immune Checkpoint Regulation against Melanoma.

Exposure to solar ultraviolet radiation (UVR) impacts various cellular, genetic, and immunologic responses governing biological and pathophysiologic events including the development of skin cancers. The mechanistic insights into UVR-induced immune tolerance against skin cancers, particularly cutaneous melanoma, have been a great challenge, given the sophisticated regulation of immune checkpoint proteins. A study led by Wang and colleagues has elucidated novel mechanisms of UVR-induced immune suppression, implicated in melanoma immune evasion and progression mediated via upregulation of PD-L1, and reduced CD8+ T-cell-mediated cytotoxicity in HMGB1/TBK1/IRF3/NF-κB-dependent manner. These findings offer new mechanistic insights into UVR-induced melanoma immune evasion and progression.See related article by Wang et al., p. 2909.