Project description:Bach2 regulates homeostasis of foxp3+ regulatory T cells and protects against fatal lung disease in mice. Cells from WT and Bach2 KO spleen were isolated. CD4+ CD25+ GITR+ (Treg) cells were sorted by FACS sorting. Total RNAs were extracted from sorted Treg cells using by Rneasy Kit (Qiagen).
Project description:Through a diversity of functional lineages, cells of the innate and adaptive immune system either drive or constrain immune reactions within tumors. Thus, while the immune system has a powerful ability to recognize and kill cancer cells, this function is often suppressed preventing clearance of disease. The transcription factor (TF) BACH2 controls the differentiation and function of multiple innate and adaptive immune lineages, but its role in regulating tumor immunity is not known. Here, we demonstrate that BACH2 is required to establish immunosuppression within tumors. We found that growth of subcutaneously implanted tumors was markedly impaired in Bach2-deficient mice and coincided with intratumoral activation of both innate and adaptive immunity but was dependent upon adaptive immunity. Analysis of tumor-infiltrating lymphocytes in Bach2-deficient mice revealed high frequencies of CD4+ and CD8+ effector cells expressing the inflammatory cytokine IFN-γ. Lymphocyte activation coincided with reduction in the frequency of intratumoral CD4+ Foxp3+ regulatory T (Treg) cells. Mechanistically, Treg-dependent inhibition of CD8+ T cells was required for BACH2-mediated tumor immunosuppression. These findings demonstrate that BACH2 is a key component of the molecular programme of tumor immunosuppression and identify a new target for development of therapies aimed at reversing immunosuppression in cancer. Analysis of tumor-infiltrating lymphocytes in Bach2-deficient mice revealed high frequencies of CD4+ and CD8+ effector cells expressing the inflammatory cytokine IFN-γ. Lymphocyte activation coincided with reduction in the frequency of intratumoral CD4+ Foxp3+ regulatory T (Treg) cells. Mechanistically, Treg-dependent inhibition of CD8+ T cells was required for BACH2-mediated tumor immunosuppression.
Project description:The role of FoxP3+ regulatory T (Treg) cells in the maintenance of immunological tolerance is well established. Recently, genome-wide association studies (GWAS) in humans have associated polymorphisms within the BACH2 locus encoding the transcription factor BTB and CNC homology 1, basic leucine zipper transcription factor 2 (Bach2) with diverse allergic and autoimmune diseases including asthma, multiple sclerosis, Crohn's disease, celiac disease, generalized vitiligo and type 1 diabetes. Common to these diseases is a failure to adequately maintain immunological tolerance. However, a role for Bach2 in this process has not been established. Here, by assessing the phenotype of mice in which the Bach2 gene is disrupted, we demonstrate a non-redundant role for Bach2 in the prevention of a spontaneous lethal inflammatory disorder predominantly affecting the lung and gut with excessive T helper 2 (Th2) responses and formation of circulating autoantibodies. Bach2 was necessary for efficient induction of FoxP3 expression both during thymopoesis and upon stimulation of naïve peripheral CD4+ T cells under Treg polarizing conditions in vitro. Consequently, in bone marrow reconstitution experiments, Bach2 expression within the haematopoetic system was necessary for suppression of lethal autoimmunity in a manner that was FoxP3 dependent. These findings demonstrate a requirement for Bach2 in early lineage commitment of both thymic and induced Treg cells and point to shared mechanisms that underlie diverse allergic and autoimmune disorders that may serve as targets in the development of novel therapeutic strategies. Six samples were collected from separate mice: three Ly5.1+ wildtype thymocyte samples (biological replicates) and three Ly5.1- Bach2 knockout thymocyte samples (biological replicates).
Project description:We correlated comprehensive T cell phenotyping data from peripheral blood to the corresponding genotype of different disease-associated and T cell related SNPs. This revealed significantly increased frequencies of naive CD4+ T cells (CD4+ TN) and T helper 17 (TH17) cells in carriers of intergenic SNP rs56258221 (BACH2/MIR4464) as compared to non-carriers. Functional experiments identified CD4+ TN from SNP-carriers to rather polarize towards pro-inflammatory subsets than into regulatory T cells (TREG). *** Due to data privacy concerns fastq files have not been uploaded ***
Project description:We correlated comprehensive T cell phenotyping data from peripheral blood to the corresponding genotype of different disease-associated and T cell related SNPs. This revealed significantly increased frequencies of naive CD4+ T cells (CD4+ TN) and T helper 17 (TH17) cells in carriers of intergenic SNP rs56258221 (BACH2/MIR4464) as compared to non-carriers. Functional experiments identified CD4+ TN from SNP-carriers to rather polarize towards pro-inflammatory subsets than into regulatory T cells (TREG). *** Due to data privacy concerns fastq files have not been uploaded ***
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:The differentiation and homeostasis of Foxp3+ regulatory T (Treg) cells is strictly controlled by T cell receptor (TCR) signals; however, the molecular regulators of these processes are incompletely known. Here we found that Bach2 was a key regulator of Treg cell differentiation and homeostasis downstream of TCR signalling. Bach2 prevented premature differentiation of fully suppressive effector (e)Treg cells, limited IL-10 production and was required for the development of peripherally induced (p)Treg cells in the gastrointestinal tract. We found that Bach2 attenuated TCR signalling-induced and IRF4-dependent Treg cell differentiation programs. Deletion of IRF4 promoted inducible Treg cell differentiation and rescued pTreg cell differentiation in the absence of Bach2. In turn, loss of Bach2 normalised eTreg cell differentiation of IRF4-deficient Treg cells. Mechanistically, Bach2 counteracted DNA-binding activity of IRF4 and limited chromatin accessibility, thereby attenuating IRF4-dependent transcriptional programs. Thus, Bach2 balanced TCR signalling induced transcriptional activity of IRF4 to maintain Treg cell homeostasis.