Single-cell RNA sequencing of emigrating cells from human psoriasis skin and control normal skin
Single-cell RNA sequencing is transforming how we understand skin immunology, but previous human skin single-cell RNA sequencing data included only a small fraction of inflammatory cells among the overall cell population, such that functional subsets may be difficult to ascertain. We have overcome these obstacles by harvesting inflammatory cells emigrating from a half of 6 mm punch biopsy skin after 48-hour incubation in culture medium without any enzyme, and then analyzing the harvested cells with single-cell RNA sequencing. By this strategy, we obtained single-cell RNA sequencing data of 24,354 cells (leukocytes 46.0%, keratinocytes 49.6%, and melanocytes 2.4%) from 13 human psoriasis skin and 5 healthy volunteer skin. Unsupervised clustering identified NK cells, CD161+ T-cells, CD8+ T-cells, CD4+ T-cells, regulatory T-cells, mature & semimature dendritic cells, melanocytes, and keratinocytes in different layers - S. (Stratum) corneum, S. granulosum, S. spinosum, and S. basale. To understand psoriasis immunopathogenesis at single-cell levels, we compared gene expression between psoriasis cells vs. control cells within each inflammatory cell subtype clusters. Overall design: Transcriptome profiles of 13 human psoriasis lesional skin and 5 healthy volunteers' normal control skin were generated by droplet-based single cell RNA-sequencing.