Project description:RNASeq: Aryl hydrocarbon receptor governs a transcriptional programme that determines regulatory B cell differentiation and function
Project description:The transcription factor Pax5 represses B-lineage-inappropriate genes and activates B-cell-specific genes in B-lymphocytes. Here we have identified 170 novel Pax5-activated genes. Conditional mutagenesis demonstrated that the Pax5-regulated genes require continuous Pax5 activity for normal expression in pro-B and mature B cells. Expression of half of the Pax5-activated genes is either absent or significantly reduced upon Pax5 loss in plasma cells. Direct Pax5 target genes were identified based on their protein synthesis-independent activation by a Pax5-estrogen receptor fusion protein. Chromatin immunoprecipitation (ChIP) of Pax5 together with chromatin profiling by ChIP-on-chip analysis demonstrated that Pax5 directly activates the chromatin at promoters or putative enhancers of Pax5 target genes. The novel Pax5-activated genes code for key regulatory and structural proteins involved in B cell signaling, adhesion, migration, antigen presentation and germinal center B cell formation, thus revealing a complex regulatory network, which is activated by Pax5 to control B cell development and function. Keywords: Chip-chip, cell type comparison comparison of Pax5-/-Rag2-/- vs Rag2-/- pro-B cells
Project description:The transcription factor Pax5 represses B-lineage-inappropriate genes and activates B-cell-specific genes in B-lymphocytes. Here we have identified 170 novel Pax5-activated genes. Conditional mutagenesis demonstrated that the Pax5-regulated genes require continuous Pax5 activity for normal expression in pro-B and mature B cells. Expression of half of the Pax5-activated genes is either absent or significantly reduced upon Pax5 loss in plasma cells. Direct Pax5 target genes were identified based on their protein synthesis-independent activation by a Pax5-estrogen receptor fusion protein. Chromatin immunoprecipitation (ChIP) of Pax5 together with chromatin profiling by ChIP-on-chip analysis demonstrated that Pax5 directly activates the chromatin at promoters or putative enhancers of Pax5 target genes. The novel Pax5-activated genes code for key regulatory and structural proteins involved in B cell signaling, adhesion, migration, antigen presentation and germinal center B cell formation, thus revealing a complex regulatory network, which is activated by Pax5 to control B cell development and function. Keywords: Chip-chip, cell type comparison comparison of Pax5-/-Rag2-/- vs Rag2-/- pro-B cells
Project description:Analysis of Foxp3 ablated peripheral regulatory T cells. Regulatory T cells require the expression of the transcription factor Foxp3 for thymic development. It is not known whether continuous expression of Foxp3 is required for the maintained function of mature regulatory T cells in the periphery. Results indicate changes to the regulatory T cell developmental program in the absence of Foxp3. Keywords: genetic modification
Project description:During development, thymocytes bearing a moderately self-reactive T cell receptor (TCR) can be selected to become regulatory T (Treg) cells. Several observations suggest that also in the periphery mature Treg cells continuously receive self-reactive TCR signals. However, the importance of this inherent autoreactivity for Treg cell biology remains poorly defined. To address this open question, we genetically ablated the TCR of mature Treg cells in vivo. These experiments revealed that TCR-induced Treg lineage-defining FoxP3 expression and gene hypomethylation were uncoupled from TCR input in mature Treg cells. However, Treg cell homeostasis, cell-type-specific gene expression and suppressive function critically depend on continuous triggering of their TCR.
Project description:Analysis of Foxp3 ablated peripheral regulatory T cells. Regulatory T cells require the expression of the transcription factor Foxp3 for thymic development. It is not known whether continuous expression of Foxp3 is required for the maintained function of mature regulatory T cells in the periphery. Results indicate changes to the regulatory T cell developmental program in the absence of Foxp3. Experiment Overall Design: Compare Cre recombinase treated peripheral regulatory T cells possessing a Cre sensitive Foxp3 locus to Cre treated regulatory T cells with a wild type Foxp3 locus. Cre exposure is observed via the Cre sensitive expression of the yellow flourescent protein molecule.