Effect of depletion of Ku70 on gene expression profiles of murine regulatory T cells in lung tumor microevnronment

The functions of the DNA repair protein Ku70 in immune homeostasis and tumor immunity remain unexplored. Here, we conducted deep sequencing of mRNA profiles from tumor-infiltrating Treg cells (from Foxp3Cre and Xrcc6fl/fl;Foxp3Cre mice injected with Lewis lung carcinoma cells). By comparing gene expression profiles, we found that Ku70-absent Treg displayed activated pathways in response to inflammatory factors and upregulated expression of genes negatively regulated by Foxp3. These findings strongly indicate that Ku70 plays a supportive role in enhancing Foxp3 transcriptional activity. Overall design: To investigate the role of Ku70 in the regulating of Treg function, we generated Treg cell-specific knockout mice (Xrcc6flox/floxFoxp3Yfp-Cre, cKO) and Foxp3Yfp-Cre (control, WT) mice. To establish lung metastasis model, LLC cells (1 million per mouse) were tail-intravenously injecting into 8- to 10-week-old WT and cKO mice. Tumors were excised at 21 days, and Tumor-infiltrating Treg cells were isolated for RNA sequencing.