BioRxiv

Basic-Leucine-Zipper Transcription Factors Regulate Selective Molecular Phenotypes in Regulatory T Cells During IL-2-Induced Activation

Joyce Tse, Xuan Liu, Ittai Eres, Tracy Yamawaki, Matt Kanke, Marisela Killian, Junedh Amrute, Ashutosh Chaudhry, Anupama Sahoo, Wenjun Liu, Cheng-Yuan Kao, Xin Luo, Jiamiao Lu, Daniel Lu, Songli Wang, Scott Martin, Chi-Ming Li

Abstract

Regulatory T (Treg) cells have long been recognized as modulators of immunological tolerance and homeostasis. Previously, we used scRNA-seq to reveal significant Treg heterogeneity in response to IL-2-induced activation. Herein, we leveraged enrichment analyses, as well as bulk and single-nucleus multi-omics in splenic and lung Tregs, to uncover and confirm the importance of transcription factors (TFs) and chromatin remodeling in Treg activation. Multiple bZIP TF motifs showed increased chromatin accessibility post IL-2 treatment, with correlated transcriptional changes resembling Th1 and Th2 molecular phenotypes, further confirmed by spatial ATAC-seq. By combining gene perturbation and CUT&RUN assays before and after Treg stimulation, we show that bZIP TFs, such as BATF and BACH1, are critical to IL-2-induced Treg activation, coordinating epigenetic and transcriptional changes that selectively drive T-helper phenotypes and metabolic pathways.