Project description:Thymic-derived natural T regulatory cells (nTregs) are characterized by functional and phenotypic heterogeneity. Recently, a small fraction of peripheral Tregs have been shown to express Klrg1, but it remains unclear the extent Klrg1 defines a unique Treg subset. Here we show that Klrg1+ Tregs represent a terminally differentiated Treg subset derived from Klrg1- Tregs. This subset is a recent antigen-responsive and a highly activated short-lived Treg population that expresses enhanced levels of Treg suppressive molecules and that preferentially resides within mucosal tissues. The development of Klrg1+ Tregs also requires extensive IL-2R signaling. This activity represents a distinct function for IL-2, independent from its contribution to Treg homeostasis and competitive fitness. These and other properties are analogous to terminally differentiated short-lived CD8+ T effector cells. Our findings suggest that an important pathway driving antigen-activated conventional T lymphocytes also operates for Tregs. Gene expression analysis was performed of this and other Treg subsets based on expression of CD62L, CD69, and Klrg1 to define the molecular properties of Klrg1+ Tregs and its relationship to other Treg subsets found in the peripheral immune tissues. Mice were euthanized, spleen cell preparations were made, and each Treg subset was isolated by FACS cell sorting. RNA was immediately prepared for processing.
Project description:Thymic-derived natural T regulatory cells (nTregs) are characterized by functional and phenotypic heterogeneity. Recently, a small fraction of peripheral Tregs have been shown to express Klrg1, but it remains unclear the extent Klrg1 defines a unique Treg subset. Here we show that Klrg1+ Tregs represent a terminally differentiated Treg subset derived from Klrg1- Tregs. This subset is a recent antigen-responsive and a highly activated short-lived Treg population that expresses enhanced levels of Treg suppressive molecules and that preferentially resides within mucosal tissues. The development of Klrg1+ Tregs also requires extensive IL-2R signaling. This activity represents a distinct function for IL-2, independent from its contribution to Treg homeostasis and competitive fitness. These and other properties are analogous to terminally differentiated short-lived CD8+ T effector cells. Our findings suggest that an important pathway driving antigen-activated conventional T lymphocytes also operates for Tregs. Gene expression analysis was performed of this and other Treg subsets based on expression of CD62L, CD69, and Klrg1 to define the molecular properties of Klrg1+ Tregs and its relationship to other Treg subsets found in the peripheral immune tissues.
Project description:Regulatory T cells (Tregs) are immune cells that play a crucial role in maintaining tolerance to harmless antigens, including commensal microbes. In the intestine, Tregs can be classified into subsets based on their expression of transcription factors Helios, Rorg, Gata3 and cMaf. The exact functions of the intestinal Treg subsets and their role in maintaining tolerance to intestinal microbes is not fully understood. Here, we generated conditional knockout mice of each Treg subset and profiled the composition of their intestinal microbiota by performing 16S rRNA sequencing of stool from conditional knockouts and matched littermate controls.
Project description:While unique subsets of Treg cells have been described in some non-lymphoid tissues, their relationship to Treg cells in secondary lymphoid organs and circulation remains unclear. We have identified a recirculating and highly suppressive effector Treg cell subset that expresses the α2 integrin, CD49b, and exhibits a unique tissue distribution. To identify genes and pathways enriched in CD49b+ Treg cells, we performed RNA-seq of splenic CD49b+ and CD49b− Treg cells that were of otherwise similar activation status based on expression of CD44 and CD62L. This revealed that splenic CD49b+ Treg cells express genes related to migration and activation, but are relatively depleted of genes whose expression is TCR-dependent in Treg cells. These results shed light on the identity and development of a functionally potent subset of mature effector Treg cells that recirculates through and surveys peripheral tissues.
Project description:All the sorted Treg cells are gated on CD4+CD25+CD127(low), followed by gating on various subsets using markers indicated in the sample names. All the sorted Teff cells are gated on CD4+CD25-CD127(hi), and further sorted for CD45RO- and CD45RO+ phenotype.
Project description:While unique subsets of Treg cells have been described in some non-lymphoid tissues, their relationship to Treg cells in secondary lymphoid organs and circulation remains unclear. We have identified a recirculating and highly suppressive effector Treg cell subset that expresses the α2 integrin, CD49b, and exhibits a unique tissue distribution. We used TCR sequencing to ask whether CD49b+ activated Treg cells and CD49b− activated Treg cells represent stable states of Treg cell differentiation instructed by distinct TCR repertoires. We did not find a pattern of clonotypes that was specific to either subset, suggesting that essentially all CD49b− Treg cells could give rise to CD49b+ cells. These results shed light on the identity and development of a functionally potent subset of mature effector Treg cells that recirculate through and survey peripheral tissues.
Project description:Regulatory T (Treg) cells derived from the thymus (tTreg) and periphery (pTreg) play central and distinct roles in immunosuppression, but mechanisms governing the generation and activation of Treg subsets in vivo remain uncertain. Here, we report that mechanistic target of rapamycin (mTOR) unexpectedly supports the homeostasis and functional activation of tTreg and pTreg cells. Further, mTOR signaling is crucial for programming activated Treg cell effector function to protect immune tolerance and tissue homeostasis. Treg-specific deletion of mTOR drives spontaneous TH2 responses and altered barrier tissue homeostasis, associated with reductions in both thymic derived effector Treg (eTreg) and pTreg cells. Mechanistically, mTOR acts downstream of antigenic signals to drive IRF4 expression and mitochondrial metabolism, and accordingly, disruption of mitochondrial metabolism severely impairs Treg cell suppressive function and their homeostasis in tissues. Collectively, our results demonstrate that mTOR coordinates transcriptional and metabolic programs in activated Treg subsets to mediate tissue homeostasis