Project description:T-bet and GATA3 induce differentiation of CD4+ T-cells into Th1 or Th2 effectors. These exhibit a range of different properties but understanding of T-bet and GATA3 function is mostly limited to the murine Ifng and Il4/Il5/Il13 loci. We hypothesised that extending such analyses across the human genome would allow further insight into T-bet and GATA3 function. We have discovered that T-bet and GATA3 bind to multiple distal sites at a set of key immune regulatory genes. These sites display markers of functional elements, act as enhancers in reporter assays and are associated with lineage-specific expression regulated by T-bet and GATA3. Our approach also reveals that GATA3 is distributed at T-bet binding sites in Th1 cells and that T-bet directly activates its own expression. We propose that these aspects of T-bet and GATA3 function are critical for Th1/ Th2 differentiation and provide a model for the relationship between other lineage-specific regulators. ChIP was performed using antibody against T-bet in Th1 cells and against GATA3 in Th1 cells as well as Th2 cells. A sample of whole cell extract (WCE) from Th1 cells and Th2 cells was sequenced. Th1 WCE was used as the background to determine enrichment.
Project description:T-bet and GATA3 induce differentiation of CD4+ T-cells into Th1 or Th2 effectors. These exhibit a range of different properties but understanding of T-bet and GATA3 function is mostly limited to the murine Ifng and Il4/Il5/Il13 loci. We hypothesised that extending such analyses across the human genome would allow further insight into T-bet and GATA3 function. We have discovered that T-bet and GATA3 bind to multiple distal sites at a set of key immune regulatory genes. These sites display markers of functional elements, act as enhancers in reporter assays and are associated with lineage-specific expression regulated by T-bet and GATA3. Our approach also reveals that GATA3 is distributed at T-bet binding sites in Th1 cells and that T-bet directly activates its own expression. We propose that these aspects of T-bet and GATA3 function are critical for Th1/ Th2 differentiation and provide a model for the relationship between other lineage-specific regulators.
Project description:GATA3 is indispensable for the development of all IL-7Rα-expressing innate lymphoid cells (ILCs) and maintenance of type 1 ILCs (ILC1s) and type 2 ILCs (ILC2s). However, the importance of low GATA3 expression in type 3 ILCs (ILC3s) is still elusive. Here, we report that GATA3 regulates homeostasis of ILC3s by controlling IL-7Rα expression. In addition, GATA3 is critical for the development of NKp46+ ILC3 subset partially through regulating the balance between T-bet and RORγt. Genome-wide analyses indicate that while GATA3 positively regulates CCR6+ and NKp46+ ILC3 subset-specific genes in respective lineages, it negatively regulates CCR6+ ILC3-specific genes in NKp46+ ILC3s. Furthermore, GATA3 regulates IL-22 production in both CCR6+ and NKp46+ ILC3s. Thus, low GATA3 expression is critical for the development and function of ILC3 subsets. To identify GATA3 regulated genes in total ILC3s with RNA-Seq; To identify unique genes expressed by CCR6+ ILC3 or NKp46+ ILC3 and GATA3 regulated genes within these two ILC3 subsets with RNA-Seq; To identify GATA3 direct binding sites in ILC3s, ILC2s and Th2 cells with ChIP-Seq.
Project description:T-bet is pivotal for initiation and perpetuation of Th1 immunity. Identification of novel T-bet regulated genes is crucial for further understanding the biology of this transcription factor. By combining siRNA technology with genome-wide mRNA analysis, we sought to identify new T-bet regulated genes in IL-18-activated KG1 cells. KG1 cells were transfected with either control-siRNA (siRNAc) or siRNA targeting T-bet (siRNA-Tbet) and thereafter stimulated with IL-18. Total RNA was evaluated by genome-wide analysis using the Affymetrix GeneChip® Array System.
Project description:T-bet is pivotal for initiation and perpetuation of Th1 immunity. Identification of novel T-bet regulated genes is crucial for further understanding the biology of this transcription factor. By combining siRNA technology with genome-wide mRNA analysis, we sought to identify new T-bet regulated genes in IL-18-activated KG1 cells.
Project description:Differentiation of progenitor cells into mature cell types is commonly associated with the expression of lineage-determining transcription factors (LD-TFs) specific to that lineage. In CD4+ T cells, T-bet dictates differentiation of the TH1 lineage, whereas GATA3 drives differentiation of the alternative TH2 lineage. LD-TFs, including T-bet and GATA3, are frequently co-expressed, both in vitro and in vivo. How co-expression of two mutually antagonistic LD-TFs affects their function and lineage determination is not known. By expressing T-bet and GATA3 separately or together, we show that T-bet sequesters GATA3 at its target sites, thereby removing GATA3 from TH2 genes. T-bet interacts with the GATA3 DNA binding domain, changing its DNA sequence binding preference. This mechanism allows T-bet to dominate and drive the TH1 gene expression program in the presence of the GATA3. We propose that redistribution of one LD-TF by another may be a common mechanism that could explain how specific cell fate choices can be made even in the presence of other TFs driving alternative differentiation pathways.
Project description:Differentiation of progenitor cells into mature cell types is commonly associated with the expression of lineage-determining transcription factors (LD-TFs) specific to that lineage. In CD4+ T cells, T-bet dictates differentiation of the TH1 lineage, whereas GATA3 drives differentiation of the alternative TH2 lineage. LD-TFs, including T-bet and GATA3, are frequently co-expressed, both in vitro and in vivo. How co-expression of two mutually antagonistic LD-TFs affects their function and lineage determination is not known. By expressing T-bet and GATA3 separately or together, we show that T-bet sequesters GATA3 at its target sites, thereby removing GATA3 from TH2 genes. T-bet interacts with the GATA3 DNA binding domain, changing its DNA sequence binding preference. This mechanism allows T-bet to dominate and drive the TH1 gene expression program in the presence of the GATA3. We propose that redistribution of one LD-TF by another may be a common mechanism that could explain how specific cell fate choices can be made even in the presence of other TFs driving alternative differentiation pathways.
Project description:Differentiation of progenitor cells into mature cell types is commonly associated with the expression of lineage-determining transcription factors (LD-TFs) specific to that lineage. In CD4+ T cells, T-bet dictates differentiation of the TH1 lineage, whereas GATA3 drives differentiation of the alternative TH2 lineage. LD-TFs, including T-bet and GATA3, are frequently co-expressed, both in vitro and in vivo. How co-expression of two mutually antagonistic LD-TFs affects their function and lineage determination is not known. By expressing T-bet and GATA3 separately or together, we show that T-bet sequesters GATA3 at its target sites, thereby removing GATA3 from TH2 genes. T-bet interacts with the GATA3 DNA binding domain, changing its DNA sequence binding preference. This mechanism allows T-bet to dominate and drive the TH1 gene expression program in the presence of the GATA3. We propose that redistribution of one LD-TF by another may be a common mechanism that could explain how specific cell fate choices can be made even in the presence of other TFs driving alternative differentiation pathways.
Project description:Differentiation of progenitor cells into mature cell types is commonly associated with the expression of lineage-determining transcription factors (LD-TFs) specific to that lineage. In CD4+ T cells, T-bet dictates differentiation of the TH1 lineage, whereas GATA3 drives differentiation of the alternative TH2 lineage. LD-TFs, including T-bet and GATA3, are frequently co-expressed, both in vitro and in vivo. How co-expression of two mutually antagonistic LD-TFs affects their function and lineage determination is not known. By expressing T-bet and GATA3 separately or together, we show that T-bet sequesters GATA3 at its target sites, thereby removing GATA3 from TH2 genes. T-bet interacts with the GATA3 DNA binding domain, changing its DNA sequence binding preference. This mechanism allows T-bet to dominate and drive the TH1 gene expression program in the presence of the GATA3. We propose that redistribution of one LD-TF by another may be a common mechanism that could explain how specific cell fate choices can be made even in the presence of other TFs driving alternative differentiation pathways.