Specific ablation of PD-1 on regulatory T cells promotes antitumor immunity

Regulatory T cells (Tregs) have an immunosuppressive function and highly express PD-1 in tumor microenvironment, but the function of PD-1 in Tregs is still controversial. Using murine tumor model, we demonstrated that Tregs-specific PD-1 conditional Knock-Out mice are resistant to tumor progression. Using PD-1 hetero conditional Knock-Out mice in which both PD-1 expressing Tregs and deficient Tregs co-exist, we found that specific ablation of PD-1 on Tregs results in impaired proliferative capacity and functionality of Tumor-infiltrating Tregs. Single cell RNA and VDJ sequencing revealed that PD-1 signaling in TI Tregs induces global transcriptome crucial for Tregs homeostasis and functionality. Taken together, we suggest that specific ablation of PD-1 on Tregs promotes antitumor immunity by exacerbating Tregs stability and functionality. Overall design: mRNA profile of Tumor infiltrating CD4+ T cells from Isotype control or aPD-1 treated TC-1 tumor bearing PD-1 hetero conditional KO mice (PD-1fl/fl X Foxp3eGFP-Cre-ERT2(+/-)) at day 14 after tumor injection Please note that the *Whole_Processed_*.tsv.gz files contain the GSM4995463-GSM4995466 processed data, the *Integrated-2 and *Integrated-3 files contain processed data for seq 2 and sep3 samples, respectively.