UV irradiation drives lineage-specific MITF-mediated transcription of PD-L1 to confer immune tolerance to UV-mutated melanocytes.

UV-induced activation of MITF drives PD-L1 expression in melanocytes, promoting immune tolerance and enabling survival of UV-mutated cells.

• Why it matters: Understanding how melanocytes evade immune clearance despite high mutational burdens is crucial for insights into melanoma development and immune therapies.
• What they did: The study examined primary human melanocytes and mouse models, showing MITF directly activates PD-L1 transcription independently of interferon signaling, with PD-L1 expression influenced by UV exposure.
• The result: Loss of PD-L1 in melanocytes led to immune infiltration and depigmentation, while PD-L1 deficiency increased susceptibility to immune attack, highlighting a melanocyte-intrinsic tolerance mechanism that impacts melanoma immune evasion and therapy response.