Project description:Naïve CD4+ T-helper cells differentiate into Th2 effector cells during asthma and helminth (worm) infection. Here, we report that mice lacking the transcription factor Bcl11b in mature CD4+ T-cells are incapable of mounting an effective Th2 response in asthma and worm infection, with a major reduction of Th2 cytokine secretion and GATA3 expression. We found that Bcl11b exerts its role in Th2 differentiation through several avenues: (1) association with intronic regions at the Gata3 locus, sustaining GATA3 expression; (2) binding to and restricting chromatin accessibility at the Il4 silencer, located at hypersensitivity site (HS) IV; and (3) restricting Runx3 expression by association with a regulatory region 5’ of Runx3. Thus, in the absence of Bcl11b, the reduction in GATA3 levels combined with increased Runx3 levels and activity at Il4 HS IV silencer and consequently diminished IL-4 expression. This results in reduced chromatin opening at the Th2 locus control region (LCR), Il13 and Il5 promoters, subsequently preventing expression of Th2 cytokine genes and Th2 differentiation. Our results establish a novel role for Bcl11b in the regulatory loop critical for licensing the Th2 program in vivo.
Project description:Naïve CD4+ T-helper cells differentiate into Th2 effector cells during asthma and helminth (worm) infection. Here, we report that mice lacking the transcription factor Bcl11b in mature CD4+ T-cells are incapable of mounting an effective Th2 response in asthma and worm infection, with a major reduction of Th2 cytokine secretion and GATA3 expression. We found that Bcl11b exerts its role in Th2 differentiation through several avenues: (1) association with intronic regions at the Gata3 locus, sustaining GATA3 expression; (2) binding to and restricting chromatin accessibility at the Il4 silencer, located at hypersensitivity site (HS) IV; and (3) restricting Runx3 expression by association with a regulatory region 5’ of Runx3. Thus, in the absence of Bcl11b, the reduction in GATA3 levels combined with increased Runx3 levels and activity at Il4 HS IV silencer and consequently diminished IL-4 expression. This results in reduced chromatin opening at the Th2 locus control region (LCR), Il13 and Il5 promoters, subsequently preventing expression of Th2 cytokine genes and Th2 differentiation. Our results establish a novel role for Bcl11b in the regulatory loop critical for licensing the Th2 program in vivo.
Project description:Naïve CD4+ T-helper cells differentiate into Th2 effector cells during asthma and helminth (worm) infection. Here, we report that mice lacking the transcription factor Bcl11b in mature CD4+ T-cells are incapable of mounting an effective Th2 response in asthma and worm infection, with a major reduction of Th2 cytokine secretion and GATA3 expression. We found that Bcl11b exerts its role in Th2 differentiation through several avenues: (1) association with intronic regions at the Gata3 locus, sustaining GATA3 expression; (2) binding to and restricting chromatin accessibility at the Il4 silencer, located at hypersensitivity site (HS) IV; and (3) restricting Runx3 expression by association with a regulatory region 5’ of Runx3. Thus, in the absence of Bcl11b, the reduction in GATA3 levels combined with increased Runx3 levels and activity at Il4 HS IV silencer and consequently diminished IL-4 expression. This results in reduced chromatin opening at the Th2 locus control region (LCR), Il13 and Il5 promoters, subsequently preventing expression of Th2 cytokine genes and Th2 differentiation. Our results establish a novel role for Bcl11b in the regulatory loop critical for licensing the Th2 program in vivo.
Project description:CD69 is a transmembrane protein expressed on the surface of activated leukocyte. The ligand for CD69 and the intracellular signaling pathway of this molecule are yet unknown. It is widely used as a marker of activated lymphocyte, but its function in immune system is not known. We used micro-array to define genes whose expression is regulated by activation antigene CD69. CD4 T cells were isolated from the spleen of wt B6 and CD69-deficient B6 mice and in vitro activated with anti-CD3/anti-CD28 coated beads. On one groupe of wt B6 cells, CD69 was activated using a anti-CD69 and secoundary antibody. RNA extraction and hybridization on Affymetrix microarrays was performed for wt B6, CD69-activated wt B6 and CD69-deficient B6 CD4 T cells.
Project description:GATA-binding protein 3 (GATA3) acts as the master transcription factor for type 2 T helper (Th2) cell differentiation and function. However, it is still elusive how GATA3 function is precisely regulated in Th2 cells. Here, we report that the transcription factor B cell lymphoma 11b (Bcl11b), a previously unknown component of GATA3 transcriptional complex, is involved in GATA3-mediated gene regulation. Bcl11b binds to GATA3 through protein-protein interaction, and they co-localize at many important cis-regulatory elements in Th2 cells. The expression of type 2 cytokines, including IL-4, IL-5 and IL-13, is up-regulated in Bcl11b-deficient Th2 cells both in vitro and in vivo; such up-regulation is completely GATA3-dependent. Genome-wide analyses of Bcl11b- and GATA3-regulated gene (from RNA-Seq), co-binding pattern (from ChIP-Seq), and Bcl11b-mediated epigenetic changes (in H3K27ac and DHSs) suggest that GATA3/Bcl11b complex is involved in limiting Th2 gene expression, as well as in inhibiting non-Th2 gene expression. Thus, Bcl11b controls both GATA3-mediated gene activation and repression in Th2 cells.