Project description:Regulatory T cells (Tregs) are essential for limiting adaptive immunity, and restrain type-2 inflammation in allergic disease. As Tregs function locally, the mechanisms that coordinate their suppressive role in the inflamed niche are of great interest. Here we show that group 2 innate lymphoid cells (ILC2) are critical mediators of IL-33-driven Treg expansion in allergic inflammation. ILC2-derived OX40L promotes the local expansion of Gata3high Tregs, which possess distinct transcriptional and functional programmes that enforce co-localisation with ILC2 in the inflamed airways. Using OX40 Treg-conditional mutant mice, we show that Gata3high Tregs are important for restraining adaptive type-2 immunity. Mechanistically, Gata3high Tregs modulate OX40L bioavailability on ILC2, which controls effector memory Th2 cell formation. As such, ILC2 can simultaneously engage both the effector and regulatory arms of adaptive type-2 immunity via the OX40L-OX40 signalling axis. More specifically, ILC2-Treg interactions serve as a critical feedback mechanism to control adaptive type-2 immunity.
Project description:With the aim of understanding how Treg cells in highly vascularized tissues are related to Treg cells in other organs, we performed RNA-seq analysis of bulk Treg and Tconv cells isolated from liver, blood, spleen, and the liver-draining portal lymph node. This revealed a clear separation of cell transcriptomes by both tissue and Treg/Tconv identity, with cells from the liver falling between blood- and spleen-derived cells. Compared to splenic Treg cells, hepatic Treg cells were enriched for genes related to proliferation and activation, and genes encoding chemokine and cytokine receptors.
Project description:Regulatory T (Treg) maintain the tumor microenvironment in an immunosuppressive state preventing effective anti-tumor immune response. A possible strategy to overcome Treg cell suppression focuses on OX40, a costimulatory molecule expressed constitutively by Treg cells while induced in activated effector T (Teff) cells. OX40 stimulation by the agonist mAb OX86 inhibits Treg cell suppression and boosts Teff cell activation. Here we uncover the mechanisms underlying the therapeutic activity of OX86 treatment dissecting its distinct effects on Treg and on effector memory T (Tem) cells, which are the most abundant CD4+ populations strongly expressing OX40 at the tumor site. In response to OX86, tumor-infiltrating Treg cells produced significantly less interleukin 10 (IL-10), possibly in relation to a decrease in the transcription factor IRF1. Tem cells responded to OX86 by upregulating surface CD40L expression, providing a licensing signal to dendritic cells (DCs). The CD40L/CD40 axis was required for Tem cell-mediated in vitro DC maturation and in vivo DC migration. Accordingly, OX86 treatment was no longer therapeutic in CD40 KO mice. In conclusion, following OX40 stimulation, blockade of Treg cell suppression and enhancement of the Tem cell adjuvant effect both concurred to free DCs from immunosuppression and to activate the immune response against the tumor. Total RNA obtained from sorted mouse FoxP3-GFP+ Treg activated in vitro with anti-CD3 in the presence of an OX40-agonist mAb (OX86) or isotype control.
Project description:Regulatory T (Treg) maintain the tumor microenvironment in an immunosuppressive state preventing effective anti-tumor immune response. A possible strategy to overcome Treg cell suppression focuses on OX40, a costimulatory molecule expressed constitutively by Treg cells while induced in activated effector T (Teff) cells. OX40 stimulation by the agonist mAb OX86 inhibits Treg cell suppression and boosts Teff cell activation. Here we uncover the mechanisms underlying the therapeutic activity of OX86 treatment dissecting its distinct effects on Treg and on effector memory T (Tem) cells, which are the most abundant CD4+ populations strongly expressing OX40 at the tumor site. In response to OX86, tumor-infiltrating Treg cells produced significantly less interleukin 10 (IL-10), possibly in relation to a decrease in the transcription factor IRF1. Tem cells responded to OX86 by upregulating surface CD40L expression, providing a licensing signal to dendritic cells (DCs). The CD40L/CD40 axis was required for Tem cell-mediated in vitro DC maturation and in vivo DC migration. Accordingly, OX86 treatment was no longer therapeutic in CD40 KO mice. In conclusion, following OX40 stimulation, blockade of Treg cell suppression and enhancement of the Tem cell adjuvant effect both concurred to free DCs from immunosuppression and to activate the immune response against the tumor.
Project description:miRNA expression profiling in highly purified murine CD4+ Tconv and Treg cells. FoxP3-GFP-hCre1a(high) reporter mice were used to separate both populations based on surface markers and presence or absence of GFP. Two-condition experiment, Tconv vs. Treg. Biological replicates: 1 Tconv, 1 Treg, purified from the same pooled mice. One replicate on 1 array.
Project description:Microarray used to detail the global gene transcription underlying sorted IFNg+ and IFNg- Tregs (CD4+CD25+CD127lo) and Tconv (CD4+CD25-CD127+) for fresh (unexpanded) and 14 day expanded cells from human blood. Treg and Tconv were FACS isolated from five healthy subjects (median age of 26, range 22-30). Sorted cells were separated into two groups: the first group was stimulated for 4 hours with PMA/ionomycin and labeled with the IFNg cytokine capture kit (Miltenyi Biotech) followed by FACS isolation of IFNg- and IFNg+ populations. The second set was expanded to day 14 prior to reactivation and cytokine cell capture. For each IFNg sorted population, cells were pelleted and flash frozen before RNA isolation and processing.
Project description:Regulatory T cells (Tregs) are essential for limiting adaptive immunity, and restrain type-2 inflammation in allergic disease. As Tregs function locally, the mechanisms that coordinate their suppressive role in the inflamed niche are of great interest. Here we show that group 2 innate lymphoid cells (ILC2) are critical mediators of IL-33-driven Treg expansion in allergic inflammation. ILC2-derived OX40L promotes the local expansion of Gata3high Tregs, which possess distinct transcriptional and functional programmes that enforce co-localisation with ILC2 in the inflamed airways. Using OX40 Treg-conditional mutant mice, we show that Gata3high Tregs are important for restraining adaptive type-2 immunity. Mechanistically, Gata3high Tregs modulate OX40L bioavailability on ILC2, which controls effector memory Th2 cell formation. As such, ILC2 can simultaneously engage both the effector and regulatory arms of adaptive type-2 immunity via the OX40L-OX40 signalling axis. More specifically, ILC2-Treg interactions serve as a critical feedback mechanism to control adaptive type-2 immunity.
Project description:We have employed whole genome microarray expression profiling of human Treg and Tconv cells as a discovery platform to identify genes differentially expressed upon signal of pseudostarvation (either mTOR inhibition or leptin neutralizaion) responsible for proliferation of Treg cell on one side and inhibition of Tconv cells on the other. Human Treg and Tconv cells isolated from healthy donors were pretreated or not with rapamycin or leptin mAb and stimulated with anti-CD3 and anti-CD28 beads for 12h.