Effect of c-Myb deficiency on pre-selection DP thymocytes
Ontology highlight
ABSTRACT: Comparing the mRNA expression profiles of c-Myb deficient and c-Myb sufficient Tcra-/- DP thymocytes. Results provide insight into the role of c-Myb in the regulation of survival and differentiation during the pre-selection DP stage where c-Myb expression is abundant during T cell development.
Project description:Comparing the mRNA expression profiles of c-Myb deficient and c-Myb sufficient Tcra-/- DP thymocytes. Results provide insight into the role of c-Myb in the regulation of survival and differentiation during the pre-selection DP stage where c-Myb expression is abundant during T cell development. DP thymocytes were purified from four c-Myb deficient and four c-Myb sufficient mice over magnetic columns. RNA from each biological replicate was individually hybridized onto a total of eight MOE430 2.0 Chips.
Project description:Review on the role of Bcl11b in thymus and periphery and impact on diseases RNA was extracted from DP thymocytes of bcl11bf/fCd4cre/tcra-/- and tcra-/- mice. Tcra-/- mice only have preselected DP thymocytes. Such mice were used to determine the role of Bcl11b before selection, considering the defective positive selection in bcl11bf/fcd4cre mice. RNA was isolated and submitted for library generation and microarray analysis to determine expression profile of bcl11b-/- preselected DP thymocytes.
Project description:Naik et al. show that RAG gene upregulation in DP Thymocytes is controlled by DPASE, a DP-specific open chromatin region in RAG locus. Reduced RAG expression in DPASE KO mice result delayed and incomplete Tcra recombination. Transcription factor RORyt binds to DPASE and Tcra enhancer to regulate Tcra recombination in DP thymocytes.
Project description:The transcription factor Zfp335 is esstential for the survival of post-B-selection DN4 thymocytes. We utilized TCRa repertoire sequencing to assess alterations to survival duration for Zfp335-deficient DP thymocytes.
Project description:Genomewide microaarray analysis of murine DP thymocytes to determine the genes whose expression was altered by FLVCR loss Gene signatures from Flvcr+/+ DP thymocytes was compared to gene signatures from Flvcr-/- DP thymocytes
Project description:Sustained Ca2+ entry into CD4+CD8+ double-positive thymocytes is required for positive selection. We identified a voltage-gated Na+ channel (VGSC), essential for positive selection of CD4+ T cells. Pharmacological inhibition of VGSC activity inhibited sustained Ca2+ influx induced by positive-selecting ligands and in vitro positive selection of CD4+ but not CD8+ T cells. In vivo shRNA knockdown of Scn5a specifically inhibited positive selection of CD4+ T cells. Ectopic expression of VGSC in peripheral AND CD4+ T cells bestowed the ability to respond to a positively selecting ligand, directly demonstrating VGSC expression was responsible for increased sensitivity. Thus active VGSCs in thymocytes provides a mechanism by which a weak positive selecting signal can induce sustained Ca2+ signals required for CD4+ T cell development. Pre-selected AND DP thymocytes were stimulated with plate bound peptide-loaded I-Ek Ig dimers. Genes were differentially regulated by positive and negative selection signals. The goal of this study is to identify ion-channel related genes critical for thymic positive selection, given the sustained Ca2+ entry into double positive thymocytes is required for positive selection. Total RNA of pre-selected AND thymocytes stimulated with I-Ek Ig dimers loaded with the positively-selecting peptide gp250, the negatively-selecting agonist peptide MCC, or the non-selecting control peptide Hb were used for the transcriptional profiling analysis. We found 28 genes were differentially down-regulated by MCC stimulation but upregulated by gp250 stimulation. One of them, scn4b, was ion-channel related.
Project description:We wanted to test the role of mammalian E proteins E2A and HEB in the development of T cells. Using a conditional deletion system in which these proteins are deleted at the DP stage of T cell development, we compared DP thymocytes deficient for E2A, HEB or both to wild-type thymocytes
Project description:CD4+ and CD8+ double-positive (DP) thymocytes are at a critical stage during the T cell development in thymus. DP cells rearrange the T cell receptor gene Tcra to generate T cell receptors with TCR. Then DP cells differentiate into CD4 or CD8 single-positive (SP) thymocytes, Regulatory T cells, or invariant nature kill T cells (iNKT) according to the TCR signal. Chromatin organizer SATB1 is highly expressed in DP cells and plays an essential role in regulating Tcra rearrangement and differentiation of DP cells. Here we explored the mechanism of SATB1 orchestrating gene expression in DP cells. Single-cell RNA sequencing assay of SATB1-deficient thymocytes showed that the cell identity of DP thymocytes was changed, and the genes specifically highly expressed in DP cells were down-regulated. ChIP-seq and ATAC-seq data showed the similar tendency. The super-enhancers regulate the expressions of the DP-specific genes, and the SATB1 deficiency reduced the super-enhancer activity. Hi-C data showed that interactions in super-enhancers and between super-enhancers and promoters decreased in SATB1 deficient thymocytes. We further explored the regulation mechanism of two SATB1-regulating genes, ETS2 and Bcl6, in DP cells and found that the knockout of the super-enhancers of these two genes impaired the development of DP cells. Our research reveals that SATB1 globally regulates super-enhancers of DP cells and promotes the establishment of DP cell identity, which helps understand the role of SATB1 in thymocyte development.