Project description:OT-1 Transgenic CD8 T-cells were isolated from spleens of WT, PKCθ theta KO, and p50 cRel DKO mice. The T-cells were either cultured with non-pulsed DC (WT only and signified as "WT - UN") or with BMDCs pulsed with the OVA peptide SIINFEKL (N4) (WT, PKCθ theta KO, and p50 cRel DKO and signified as 'genotype - N4') at a ratio of 1:10 (DC:T-cell) for 18 hours. DCs then were depleted from the culture and RNA was made from the T-cells to measure gene expression at the early / late stage of T-cell activation
Project description:NF-kB plays a crucial role in immunity to infection. This transcription factor consists in different combinatory homo- and hetero-dimers of the five members of the Rel family. cRel/p50-containing dimers have been involved in the development and function of the immune cells. However, the transcriptional roles of these two subunits still remain poorly explored in innate immune cells. By a multiple approach integrating ex vivo genomic analysis and an in vivo experimental study, we have investigated the consequences of the combined absence of cRel and p50 subunits of NF-kB in the innate response to infection. We have performed gene profiling of cRel-/-p50-/- (DKO) and wild type (WT) peritoneal macrophages stimulated with endotoxin for 2, 6 or 18 hours.
Project description:Adaptive immune responses to infection result in the formation of memory T and B cells that respond more rapidly and robustly to reinfections, providing the basis of the immunological memory targeted by vaccines. Underlying the enhanced responsiveness of memory cells is their ability to rapidly up-regulate the transcription of key effector genes at a higher level compared to naïve cells (termed transcriptional memory). While transcriptionally permissive histone modifications are known to provide chromatin structures that facilitate transcriptional memory, the molecular mechanisms that underpin this process still remain elusive. The role of the cytoplasmic signalling kinase, PKC-θ in T cell signalling cascades is well established, however PKC-θ has also recently been described as a chromatin-modifying enzyme. We have previously demonstrated that PKC-θ forms a part of an active transcription complex that docks at the IL2 gene - a gene which displays transcriptional memory. In this study, we perturbed PKC-θ expression using approaches such as siRNA knockdown in primary human naïve and memory CD4+ T cells to show that transcriptional memory is highly dependent on PKC-θ, particularly in memory CD4+ T cells. Chromatin-tethered PKC-θ was immuno-precipitated with high levels of the activating marks, H3K4me3 and H3K9ac and low levels of the repressive mark, H3K27me3 at the IL2 promoter in ex vivo-derived, activated memory CD4+ T cells. Further ChIP-sequencing analysis revealed that PKC-θ was prevalent at transcriptionally permissive domains such as promoters, upstream regions and exons but also at intronic regions containing putative enhancers annotated to a subset of genes preferentially expressed in memory CD4+ T cells. Collectively, these data argue that chromatin-tethered PKC-θ can directly regulate genes to establish and maintain a permissive chromatin state that facilitates transcriptional memory in human CD4+ T cells.
Project description:Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) regulates EMT by acting as a critical chromatin-anchored switch for inducible genes. Genome-wide transcriptome analysis identifies a unique cohort of inducible PKC-θ-sensitive genes in MCF7 cells stimulated with phorbol ester. MCF7 Cells treated with mock or siRNA against PKCtheta were left unstimulated or stimulated with PMA. No replicates.
Project description:NFkB is a family of transcriptional factors that are responsible for inflammatory and immune gene expression. RelA, RelB and cRel are the transactivation domain containing family members. P50 encoded by Nfkb1 is the primary dimerization partner. Many NFkB deficient mice are embryonic lethal. In order to identify NFkB dependent genes, MEF were isolated from Rela-/-cRel-/-, Rela-/-cRel-/-Nfkb1-/- and Rela-/-Relb-/-cRel-/- embryos at E12.5. They were treated with 100ng/ml LPS for 1hr and then profiled gene expression by microarray.
Project description:The breast tumour microenvironment (TME) includes fibroblasts, adipocytes, inflammatory and immune cells. While treatment of tumours with chemotherapeutic agents such as Docetaxel, leads to apoptosis of tumour cells, it can also have consequences for the cellular makeup and transcriptional profile of the TME and these, like increased epithelial mesenchymal transition can promote undesirable consequences, such as Cancer Stem Cell development. PKC-theta may have a role in these undesired effects. To be able to examine the effects of co-treatment of Docetaxel with an inhibitor of PKC-theta, we performed RNA-seq on tumours from mice injected with the human breast cancer cell line MDA-MB-231. We then separated reads mapped to the human and mouse genomes in silico, creating tumour and TME transcriptomes for control, Docetaxel, PKC-theta inhibitor and combination treated mice. Separation of the tumour and TME profiles illustrated a role for PKC-theta in the induction of a more basal-type transcriptome in the tumour, and of EMT in the TME.
Project description:Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) regulates EMT by acting as a critical chromatin-anchored switch for inducible genes. Genome-wide transcriptome analysis identifies a unique cohort of inducible PKC-θ-sensitive genes in MCF7 cells stimulated with phorbol ester.