The interferon-rich skin environment regulates Langerhans cell ADAM17 to promote photosensitivity in lupus [array]

ABSTRACT: The autoimmune disease lupus erythematosus (lupus) is characterized in part by photosensitivity, where patients can develop inflammatory skin lesions with even ambient ultraviolet radiation (UVR) exposure. Evidence points to a role for type I interferon (IFN-I) in photosensitivity, but mechanistic understanding remains limited. We have shown that photosensitivity in lupus models is at least in part attributable to Langerhans cell (LC) dysfunction. Healthy LCs limit photosensitivity via a disintegrin and metalloprotease 17 (ADAM17), a sheddase that normally limits UVR-induced skin inflammation by releasing soluble epidermal growth factor receptor (EGFR) ligands to support keratinocyte survival. On the other hand, LCs from lesional and even non-lesional lupus model skin show reduced ADAM17 activity and mRNA expression. Non-lesional human lupus skin also showed evidence of LC dysfunction, and, here, we asked how the lupus skin environment contributes to this dysfunction. We show that non-lesional skin in human CLE and multiple photosensitive lupus models share gene expression patterns consistent with a high IFN environment and LC dysfunction. IFN-I inhibits murine and human LC ADAM17 activity, and anti-IFNAR1 in lupus models restores LC ADAM17 function and reduces photosensitivity in EGFR and LC ADAM17-dependent manners. Reactive oxygen species (ROS) are a mediator of ADAM17 activity, and we show that lupus models have reduced UVR-induced LC ROS generation that is restored by anti-IFNAR1. Our findings suggest shared pathogenic mechanisms of photosensitivity in human and murine lupus skin and a model whereby the IFN-I-rich microenvironment in non-lesional lupus skin inhibits UVR-induced ADAM17 activity, predisposing to photosensitivity. Our data also suggest that the beneficial effects of the recently FDA-approved anifrolumab (anti-IFNAR1) on human lupus skin could act in part by restoring LC function.

ORGANISM(S): Homo sapiens

PROVIDER: GSE227329 | GEO | 2023/04/10

REPOSITORIES: GEO