Validation and discovery of mechanisms that promote vitiligo pathogenesis using single-cell RNA-sequencing of cells isolated from skin interstitial fluid

Abstract

Abstract Vitiligo is an autoimmune disease in which CD8+ T cells destroy melanocytes, leading to patchy, depigmented lesions of the skin. To investigate possible immune processes in the skin that could explain the patchy appearance of vitiligo inflammation, we performed single-cell RNA-sequencing on cells isolated from the skin using a modified suction blistering technique. We compared the transcriptomes of cells isolated from lesional and non-lesional skin of six vitiligo subjects with active, spreading lesions as well as normal skin from six healthy subjects. Using differential gene analysis to cluster more than 18,000 cell transcriptomes in an unbiased fashion, we were able to identify the cellular components of the skin: melanocytes, keratinocytes, and Langerhans cells, as well as subgroups of immune cells. Consistent with previous findings by our group and others, this approach revealed an IFNγ signature in vitiligo lesions. This method identified 87 ligand-receptor pairs that may promote vitiligo pathogenesis, including CXCR6 and CXCL16 that were just recently implicated in vitiligo. The data set also revealed that Langerhans cells actively express many genes which have known risk alleles for vitiligo, highlighting a potential pivotal role in the development of vitiligo. Overall, single-cell RNA-sequencing of the skin infiltrate in vitiligo lesions is providing robust data that confirms many previous findings, but adds additional layers of nuance missed by conventional studies of bulk material. This level of resolution will yield powerful insight into the identification of novel drug targets in previously unknown signaling pathways in vitiligo and other diseases of the skin.