164 Tissue differentiation of IL26+ TH17 cells into IL-17A producers via an epithelial crosstalk

Interleukin (IL)-26 is a TH17 cytokine with known antimicrobial and pro-inflammatory functions. However, the precise role of IL-26 in context pathogenic responses unknown. Here we identify population blood Th17 intermediates that produce high levels differentiate into IL-17A-producing cells upon TGF-b1 exposure in-vitro. By combining single cell RNA sequencing, TCR sequencing spatial transcriptomics found this process occurs psoriatic skin. In fact, IL-26+ infiltrated skin, induced expression basal keratinocytes thereby promoted their own differentiation cells. Thus, our study identifies IL-26-producing as an early stage infiltrates tissues controls its maturation IL17A-producing cells, via epithelial crosstalk involving paracrine production TGF-b1.