Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of the combination of two transcription factors on the expression of the Treg transcriptional signature, CD4+ Tconv cells activated with anti-CD3+CD28 beads were retrovirally transduced with cDNAs encoding EOS and LEF1, or GATA1 and SATB1. The cells were then sorted into Trizol, and RNA was purified, labeled and hybridized to Affymetrix arrays.
Project description:Comparison of epigenome and Tcf1 occupancy between control and Tcf1/Lef1-deficient CD8 T cells Control mice or those are deficient for Tcf1 and Lef1 transcription factors (deleted by CD4-Cre) were used to isolate thymocytes. The thymocytes were surface-stained to identify TCRbeta high, CD69â, CD24â CD8+ subsets. These cells were sorted for ChIPseq analysis of various histone marks. Control mice or those are deficient for Tcf1 (deleted by CD4-Cre) were used to isolate thymocytes. The splenocytes were surface-stained to identify TCRbeta high, CD8+ subsets. These cells were sorted for ChIPseq analysis of Tcf1 binding locations.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of FoxP3 and its candidate cofactors (Eos, Gata1, Helios, Irf4, Lef1, Satb1, Xbp1) on the expression of the Treg transcriptional signature, CD4+ conventional T cells (Tconv) activated with anti-CD3+CD28 beads were retrovirally transduced with cDNAs encoding FOXP3, candidate TFs, or a combination of FOXP3 and candidate TFs. After 3 days in culture, the transduced cells were sorted into Trizol, and RNA was purified, labeled and hybridized to Affymetrix arrays.
Project description:Comparison of transcriptome between control and Tcf1/Lef1-deficient mature CD8 thymocytes Control mice or those are deficient for Tcf1 and Lef1 transcription factors (deleted by CD4-Cre) were used to isolate thymocytes. The thymocytes were surface-stained to identify TCRbeta high, CD69â, CD24â CD8+ subsets. These cells were sorted for RNAseq analysis.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability.
Project description:Recently global gene expression profiling of patients samples lead to a molecular definition of Burkitt Lymphoma (BL) with lymphocyte enhancer-binding factor 1 (LEF1) as a signature gene. Here we report the discovery of nucleic LEF1 in a very high proportion of BL cases (15/18) and LEF1 target genes. Germinal center B cells were devoid of detectable nuclear LEF1 expression as mantle cell lymphoma (0/5), marginal zone lymphoma (0/6), follicular lymphoma (0/12) or diffuse large B cell lymphoma (DLBCL) (1/31). Using whole genome gene expression profiling after transient knockdown of LEF1 in BL cell lines, new LEF1 target genes were identified. The joint expression of these genes in primary BL samples shows that LEF1 is not only expressed aberrantly in BL but also transcriptionally active. Our study identified aberrantly expressed LEF1 and its target genes suggesting an important functional role in BLs. 3 biological replicates scrb siRNA vs LEF1 si RNA , 4 siRNA are pooled