The F3: CCL19+ Immune-interacting population was characterised by expression of genes associated with T-reticular cells (specialised fibroblasts in lymphoid organs), including genes involved in the segregation of immune cells (CCL19, CH25H), maintenance of immune cell niches (IL33, TNFSF13B), and antigen presentation (MHC-II molecules , CD74 (Supplementary figure 1f)).(Lütge, Pikor, and Ludewig 2021) T-reticular cells modulate T-cell location and activity in lymphoid organs/structures,(Lütge, Pikor, and Ludewig 2021) suggesting a similar role for F3 fibroblasts in skin.
This population also shared additional genes with F2/F3 bridge, including CXCL12, APOE, and PLA2G2A. PLA2G2A has been reported to marker a fibroblast population in cancer. APOE has been used. todescribe immune-interacting/inflammatory fibroblasts in skin more broadly.
These fibroblasts were enriched in Tcell regions in our data.
