Antigen Nonspecific Induction of Distinct Regulatory T Cell States in Oncogene-Driven Hyperproliferative Skin.

Regulatory T cells (Tregs) are recruited to nonlymphoid tissues in chronic disease, including cancer, and the tissue environment is held to shape the Treg phenotype diversity. Using single-cell RNA sequencing, we examined the transcriptomic and TCR profile of Tregs recruited to hyperproliferative HPV16 E7-expressing transgenic and control nontransgenic murine skin grafts. Tregs were more abundant in E7 transgenic skin grafts than control grafts, without evidence of E7 specificity. E7 transgenic grafts attracted both Tregs and Tregs, which were phenotypically distinct but shared a core gene signature with previously described tumor-infiltrating Tregs. Pseudotime trajectory analysis of Tregs of defined TCR clonotypes predicted phenotypic plasticity within the skin and between the skin and draining lymph nodes. Thus, oncogene-induced hyperproliferative skin expressing a single defined non-self-antigen can attract and induce non-Ag-specific Tregs that acquire distinct regulatory phenotypes characterized by specific effector gene signatures.