Zfp335 establishes neonatal immune tolerance through safeguarding effector Treg lineage commitment and maintenance [ChIP-seq]

Regulatory T (Treg) cells are crucial for maintaining peripheral immune tolerance and preventing destructive autoreactive responses, but how heterogeneous Treg populations establish tolerant status remains unclear. Here, we found that Zinc finger protein 335 (Zfp335) is indispensable for the differentiation and maintenance of effector Treg (eTreg) population and immunological self-tolerance in neonates. Mice with Zfp335 deletion in Treg cells exhibit early-onset autoimmune disease with severe inflammation in multiple organs and unrestricted activation and expansion of conventional T cells. Zfp335-deficient Treg cells display dysfunctional and pathogenic features together with multiple defects in proliferation, survival and suppressive function. Importantly, our single-cell RNA sequencing (scRNA-seq) analyses reveal distinct Treg populations and that Zfp335 deficiency causes an almost complete loss of eTreg population along with significant accumulation of dysfunctional Treg populations. Mechanistically, Zfp335 controls both fate decision and homeostasis of eTreg cells by directly targeting genes associated with homeostasis and oxidation-fueled oxidative phosphorylation (OXPHOS) and PI3K-Akt-mTOR metabolic pathways. Our data establish the concept that Zfp335 serves as a checkpoint and safeguard for eTreg lineage commitment and maintenance. Overall design: Examination of Treg cells from the lymph nodes of WT mice