Project description:Differentiation and homeostasis of Foxp3 + regulatory T cells (Tregs) are tightly controlled by the interleukin-2 receptor (IL-2R) signaling, yet the mechanisms governing these processes are incompletely understood. Here we report that transcription factor Bach2 attenuates IL-2R signaling to coordinate Treg differentiation and homeostasis by directly repressed CD25 (IL-2Rα). Thus, Bach2 balances IL-2R signaling to orchestrate development and homeostasis of various Treg subsets.
Project description:Through their functional diversification, CD4+ T cells play key roles in both driving and constraining immune-mediated pathology. Transcription factors are critical in the generation and maintenance of cellular diversity and negative regulators antagonistic to alternate fates often act in conjunction with positive regulators to stabilize lineage specification1. Polymorphisms within the locus encoding a transcription factor BACH2 are associated with diverse immune-mediated diseases including asthma2, multiple sclerosis3, Crohn¹s disease4-5, coeliac disease6, vitiligo7 and type 1 diabetes8. A role for Bach2 in maintaining immune homeostasis, however, has not been established. Here, we define Bach2 as a broad regulator of immune activation that stabilizes immunoregulatory capacity while repressing the differentiation programmes of multiple effector lineages in CD4+ T cells. Bach2 was required for efficient formation of regulatory (Treg) cells and consequently for suppression of lethal inflammation in a manner that was Treg cell dependent. Assessment of the genome-wide function of Bach2, however, revealed that it represses genes associated with effector cell differentiation. Consequently, its absence during Treg polarization resulted in inappropriate diversion to effector lineages. In addition, Bach2 constrained full effector differentiation within Th1, Th2 and Th17 cell lineages. These findings identify Bach2 as a key regulator of CD4+ T-cell differentiation that prevents inflammatory disease by controlling the balance between tolerance and immunity. The role of Bach2t to regulate immune homeostasis was investigated by mapping DNA binding profiles of Bach2 in iTreg condition. The function of Bach2 was also evaluated by comparing transcriptome in WT and Bach2-deficient iTreg cells and further comparison was done with transcriptome in naive, Th1, Th2, and Th17 conditions.
Project description:The datasets were obtained to investigate the transcriptional profile of Tfh, Tfr and Treg cells isolated from different human tissues. The comparison between lymphoid tissues with different frequency of the most mature Tfh and Tfr cells allows the investigation of maturation as well as tissue adaptation of those different cell subsets. To address these issues, three different cell populations from three different tissues were sorted by index sorting, with Tfh cells as CD4+CXCR5+ICOS+; Tfr cells as CD4+CXCR5+CD25+ and Treg cells as CD4+CXCR5-CD25+. Smart-seq2 protocol was used mRNA library preparations.
Project description:Through their functional diversification, CD4+ T cells play key roles in both driving and constraining immune-mediated pathology. Transcription factors are critical in the generation and maintenance of cellular diversity and negative regulators antagonistic to alternate fates often act in conjunction with positive regulators to stabilize lineage specification1. Polymorphisms within the locus encoding a transcription factor BACH2 are associated with diverse immune-mediated diseases including asthma2, multiple sclerosis3, Crohn¹s disease4-5, coeliac disease6, vitiligo7 and type 1 diabetes8. A role for Bach2 in maintaining immune homeostasis, however, has not been established. Here, we define Bach2 as a broad regulator of immune activation that stabilizes immunoregulatory capacity while repressing the differentiation programmes of multiple effector lineages in CD4+ T cells. Bach2 was required for efficient formation of regulatory (Treg) cells and consequently for suppression of lethal inflammation in a manner that was Treg cell dependent. Assessment of the genome-wide function of Bach2, however, revealed that it represses genes associated with effector cell differentiation. Consequently, its absence during Treg polarization resulted in inappropriate diversion to effector lineages. In addition, Bach2 constrained full effector differentiation within Th1, Th2 and Th17 cell lineages. These findings identify Bach2 as a key regulator of CD4+ T-cell differentiation that prevents inflammatory disease by controlling the balance between tolerance and immunity.
Project description:We analysed the effect of the deficiency Df(2R)ED3921 and Df(2R)ED50000 on gene expression in embryos (stage 0-11), and wing imaginal discs and brains from 3rd instar larvae. Df(2R)ED3921 and Df(2R)ED50000 were described in Ragab et al. (2005) Genetics 172:1069-1078 2005.
Project description:In various tissues, cellular homeostasis is achieved by functionally quiescent stem cells which self renew while giving rise to differentiated progeny. Regulatory T (Treg) cells are composed of functionally quiescent resting Treg (rTreg) cells which differentiate into activated Treg (aTreg) cells upon antigen stimulation. How rTreg cells remain quiescent despite chronic exposure to cognate self- and foreign antigens is unclear. The transcription factor BACH2 is critical for early Treg lineage specification but its function following lineage commitment is unresolved. Here, we show Bach2 is highly expressed in lineage-committed rTreg cells but is downregulated in aTreg cells, and upon inflammation. BACH2 binds to AP-1 sites within Treg genomes and its high expression within rTreg cells functions to restrain their TCR-driven activation and differentiation into aTreg cells. As a consequence, cell-autonomous BACH2 expression is required following Treg lineage commitment for the functional quiescence and long-term maintenance of Treg cell populations and for immune homeostasis. This SuperSeries is composed of the SubSeries listed below.
Project description:We analysed the effect of the deficiency Df(2R)ED3921 and Df(2R)ED50000 on gene expression in embryos (stage 0-11), and wing imaginal discs and brains from 3rd instar larvae. Df(2R)ED3921 and Df(2R)ED50000 were described in Ragab et al. (2005) Genetics 172:1069-1078 2005. RNA from Df(2R)ED3921 and Df(2R)ED50000 embryos was compared to a pool of RNA extracted from wild-type embryos at the same stage. For each genotype, 4 independent biological replicates were performed (2 of these dyes swapped with respect to the other two). The same experimental protocol and genotypes were used for the analysis in dissected wing imaginal discs and brains from 3rd instar larvae.
Project description:Bach2 codes for a transcriptional regulator exerting major influences on T cell mediated immune regulation. Effector CTLs derived from in vitro activation of murine CD8+ T cells showed increased proliferative and cytolytic capacity in the absence of BACH2. Before activation, BACH2-deficient CD8+ T cells had a higher abundance of memory and reduced abundance of naïve cells compared to wild-type. CTLs derived from central memory T cells were more potently cytotoxic than those derived from naïve T cells, but even within separated subsets, BACH2-deficiency conferred a cytotoxic advantage. Immunofluorescence and electron microscopy revealed larger granules in BACH2-deficient compared to wild-type CTLs, and proteomic analysis showed an increase in granule content, including perforin and granzymes. Thus, the enhanced cytotoxicity observed in effector CTLs lacking BACH2 arises not only from differences in their initial differentiation state but also inherent production of enlarged cytolytic granules. These results demonstrate how a single gene deletion can produce a CTL super-killer.