UHRF1-Mediated Maintenance DNA Methylation is Required for Induced Regulatory T Cell Function Following Influenza Induced Lung Injury in Young Adult Mice [EM-seq]

Regulatory T cells (Tregs) promote resolution of inflammation and repair of epithelial damage following lung injury, thus representing a possible cellular therapeutic for ARDS. Foxp3+ natural regulatory T cells (nTregs) require specific DNA methylation patterns maintained by the epigenetic regulator, Ubiquitin-like with PHD and RING finger domains 1, (UHRF1), to function, but the DNA methylation requirements of in vitro induced Tregs (iTregs) remain unknown. Here we tested whether the loss of Uhrf1 would augment the pro-recovery function of iTregs during viral pneumonia. We found that the loss of maintenance DNA methylation in iTregs results in reduced engraftment and a delayed repair response after experimental influenza pneumonia. Transcriptional and DNA methylation profiling of sorted Uhrf1-deficient iTregs post infection provide insight into the mechanisms underlying their impaired ability to promote repair, with Uhrf1-defiicent iTregs demonstrating greater instability via gain of alternate effector T cell lineage-defining transcription factors. Strategies to promote stability iTregs could be leveraged to further augment their pro-recovery function during pneumonia and ARDS. Overall design: Adoptively transferred Uhrf1fl/fl and Uhrf1+/+Foxp3-GFP+tdTomato+ iTreg cells were sorted from lung single cell suspension of Foxp3DTR mice infected with influenza virus on days 11 and 24 post infection. DNA libraries were subsequently generated to profile genomic CpG DNA methylation of Uhrf1-deficient and Uhrf1-sufficient iTregs following influenza infection.