Project description:To investigate the impact of TGFb on CD8 T cell activation and gene expression, we activated TCR transgenic OT-I T cells in the presence or absence of recombinant TGFb in vitro
Project description:The goal was to determine how IL-12 affects gene expression by murine CTL. Experiment Overall Design: Following RBC lysis, splenocytes from OT-1 TCR transgenic mice (5 million/ml) were cultured in six well-plates (5-6ml/well) in IMDM supplemented with 10% FCS and 55μM 2-ME with 1μM SIINFEKL. After 4 days, the cells were harvested by purification with Ficoll-Paque PLUS and placed in fresh medium containing 0 or 20ng/ml rmIL-12. Twenty-four hours later the cells were harvested and used in experiments. The live cells harvested were >98% CD8+Vα2+ (OT-1).
Project description:In mice and humans, an immature CD4-CD8- double negative (DN) thymocyte subset expresses early, mature αβTCR. These early αβTCR+ DN (EADN) cells are susceptible to leukemogenesis in both species. Using the OT-1 TCR transgenic system to model EADN-stage αβ TCR expression, we found that EADN cells show coreceptor-independent reactivity to MHC, and their TCR:MHC dependent signals can drive T-ALL transformation. We generated gene expression data from OT-1 leukemic cells and assessed their developmental stage by comparing to wild-type thymocyte subsets.
Project description:The biological functions of histone demethylases Jmjd3 and Utx remain poorly understood. We assessed such functions in developing T cells, using conditional (CD4-Cre-mediated) gene disruption, by inactivating Kdm6a and Kdm6b, respectively encoding Utx and Jmjd3, in immature CD4+CD8+ thymocytes. We compared microarray gene expression in mature (Va2hi CD24lo) mutant and wild-type CD4+CD8- thymocytes carrying the OT-II TCR transgene. We show that Jmjd3 and Utx redundantly promote H3K27Me3 removal at, and expression of, a specific subset of genes involved in terminal thymocyte differentiation, especially S1pr1, encoding a sphingosine-phosphate receptor required for thymocyte egress. Mature (Va2hi CD24lo) CD4 thymocytes were sorted from freshly prepared single-cell suspensions OT-II TCR transgenic thymocytes deficient for Utx and Jmjd3 (dKO, CD4-Cre conditional deletion of floxed Kdm6a and Kdm6b alleles), and from Cre-negative controls (wild-type). Total RNA was extracted from sorted thymocytes using the RNeasy Plus Mini Kit (Qiagen) and processed for microarray analyses (Affymetrix Mouse Exon 1.0 ST array) at the NCI microarray facility, following the manufacturer’s recommendation. Data is generated from 3 replicates from each experiment.
Project description:We report the application of TCRβ sequencing to understand T cell repertoire of matched blood and tumor samples pre and post treatment in EG7.OVA tumor bearing mice with OT-1 cell transfer. TCRβ sequencing demonstrated that OT-1 (CASSRANYEQYF) was the most abundant T-cell clone in both blood and tumors of mRBC‑OVA-4-1BBL-IL-12 treated mice. To investigate the effects of mRBC‑OVA-4-1BBL-IL-12 on immune memory, the T cell repertoire was also analyzed before and after EG7.OVA and EL4 tumor rechallenge in cured and treatment-naive mice. TCRβ sequencing on T cells in peripheral blood showed that OT-1 clones increased in frequency after EG7.OVA challenge in previously cured mice. OT-1 frequency did not increase in treatment-naïve mice after tumor challenge, indicating that the tumor alone is insufficient to drive OT-1 cell expansion. We also evaluated the frequencies of unique TCRβ sequences in T cell clones that significantly expanded post EL4 challenge (EL4 responsive TCR). Increased frequency of EL4-responsive TCRs upon each tumor challenge (EG7.OVA and EL4) was associated with complete responders (mice that rejected EL4 challenge), suggesting that T-cell-mediated protection against parental tumor antigens was generated prior to EL4 challenge. Partial responders (delayed tumor growth compared with naïve mice) had increases in EL4-responsive TCR frequencies after EL4 challenge but not during the EG7.OVA rechallenge, whereas the non-responder (tumor growth similar to naïve mice) had minimal increases in TCR frequencies upon EL4 challenge. Overall, the ability to control EL4 tumors correlated with the expansion of EL4-responsive TCR clones.
Project description:In order to identify gene targets of translational regulation during T cell activation, a polysome analysis was performed in a T cell receptor (TCR) transgenic model (OT-1) possessing a homogenous alpha-beta CD8 T lymphocyte population. Cells with defective TCR signal tranduction (Lck-/-, OFF) were compared to WT cells to visualise targets regulated by TCR signalling. Total cytoplasmic ribonucleoprotein was extracted from ex vivo OT-1 transgenic T lymphocytes stimulated with SIINFEKL peptide antigen for 24h, extracts were fractionated using a sucrose density gradient, and separated into a sub-polysomal and a polysomal fraction. Total RNA from each fraction was extracted, equal volume of RNA from each fraction was individually labelled (Sub-poly: Cy3; Poly: Cy5), and hybridised onto a Agilent SurePrint G3 Mouse GE v2 8x60K Microarray.
Project description:Oncogenic PIK3CA mutations activate phosphoinositide 3-kinase (PI3K) and are among the commonest somatic mutations in cancer and mosaic, developmental overgrowth disorders. We recently demonstrated that the ‘hotspot’ variant PIK3CAH1047R exerts striking allele dose-dependent effects on stemness in human induced pluripotent stem cells (iPSCs), and moreover demonstrated multiple oncogenic PIK3CA copies in a substantial subset of human cancers. To identify the molecular mechanism underpinning PIK3CAH1047R allele dose-dependent stemness, we profiled isogenic wild-type, PIK3CAWT/H1047R and PIK3CAH1047R/H1047R iPSCs by high-depth transcriptomics, proteomics and reverse-phase protein arrays (RPPA). PIK3CAH1047R/H1047R iPSCs exhibited altered expression of 5644 genes and 248 proteins, whereas heterozygous hPSCs showed 492 and 54 differentially-expressed genes and proteins, respectively, confirming a nearly deterministic phenotypic effect of homozygosity for PIK3CAH1047R. Pathway and network-based analyses predicted a strong association between self-sustained TGFb/NODAL signaling and the ‘locked’ stemness phenotype induced by homozygosity for PIK3CAH1047R. This stemness gene signature was maintained without exogenous NODAL in PIK3CAH1047R/H1047R iPSCs and was reversed by pharmacological inhibition of TGFb/NODAL signaling but not by PIK3CA-specific inhibition. Analysis of PIK3CA-associated human breast cancers revealed increased expression of the stemness markers NODAL and POU5F1 as a function of disease stage and PIK3CAH1047R allele dosage. Together with emerging realization of the link between NODAL re-expression and aggressive cancer behavior, our data suggest that TGFb/NODAL inhibitors warrant testing in advanced breast tumors with multiple oncogenic PIK3CA copies.
Project description:The biological functions of histone demethylases Jmjd3 and Utx remain poorly understood. We assessed such functions in developing T cells, using conditional (CD4-Cre-mediated) gene disruption, by inactivating Kdm6a and Kdm6b, respectively encoding Utx and Jmjd3, in immature CD4+CD8+ thymocytes. We compared microarray gene expression in mature (Va2hi CD24lo) mutant and wild-type CD4+CD8- thymocytes carrying the OT-II TCR transgene. We show that Jmjd3 and Utx redundantly promote H3K27Me3 removal at, and expression of, a specific subset of genes involved in terminal thymocyte differentiation, especially S1pr1, encoding a sphingosine-phosphate receptor required for thymocyte egress.
Project description:This experiment aims to study the transcriptome of activated T cells at 24h, using the same biological samples as the polysome profiling in GSE84781. A T cell receptor (TCR) transgenic mouse model (OT-1) posessing a homogenous alpha-beta CD8 T lymphocyte population was used, and cells with intact TCR signalling pathways (WT) were compared to those with defective signal transduction (Lck-/-, OFF). Ex vivo OT-1 T cells were isolated from the superficial cervicals, axillary, brachial, mesenteric, and inguinal lymph nodes and then activated for 24h with cognate peptide antigen SIINFEKL. Total RNA was extracted from the cells, labelled with Cy3, and hybridised onto an Agilent-074809 SurePrint G3 Mouse GE v2 8x60K Microarray.