Project description:Peripheral Blood Mononuclear Cells (PBMCs) were isolated from a buffy coat (Australian Blood Bank) using Ficoll methodology. CD4+ T cells were isolated using Dynal Beads kit. Pure CD4+ T cells were then stained using a cocktail of monoclonal antobodies (mAbs), including: anti-CD4PE, CD45RO ECD, CD62L APC-Cy7, CD25 APC, CD127 Pacific Blue. After incubation, cells were washed twice in PBS/FCS (0.2%), and sorted into five different cell subsets: CD4+CD25+CD127low CD62L+CD45RO- (naive regulatory T cells), CD4+CD25+CD127low CD62L+/- CD45RO+ (activated regulatory T cells), CD4+CD25+CD127hi CD62L+/- CD45RO+ (memory T cells), CD4+CD25-CD127low CD62L+/- CD45RO+ (effector T cells) and CD4+CD25-CD127hi CD62L+ CD45RO- (naive T cells).
Project description:Gene expression profiling of human CD8+ CD161hi and CD161lo central and effector memory and naïve T cell subsets. The mechanisms by which IL-17 secreting cells are regulated have not been completely elucidated. We previously identified a population of rhodamine-effluxing memory CD8+ T cells with high expression of CD161 that contributes to immune reconstitution after lymphopenia-inducing chemotherapy. Here we find that CD161hi CD8+ T cells share transcriptional programming with Th17 cells, but most do not secrete IL-17 or proliferate to stimulation through the T cell receptor (TCR). Transcriptional analysis of subsets identified by expression of CD161 and CD62L revealed a novel mechanism of TCR signaling pathway regulation in CD161hi CD8+ T cells that is distinct from that described in anergic or tolerant cells and renders them functionally dependent on costimulation through innate cytokine receptors or CD28. CD161hi CD8+ T cells, induced to proliferate by a TCR signal delivered with costimulation, demonstrated plasticity that was dependent on the nature of costimulation and resulted in expansion of IL-17 secreting cells that could not proliferate to a TCR signal alone or differentiation to Tc1-like cells that proliferated to TCR stimulation in the absence of costimulation. The data show an association between TCR signaling pathway downregulation and type 17 programming in CD161hi CD8+ T cells, whose dysregulation could mediate IL-17 dependent inflammatory diseases. T cell subsets were sort-purified from healthy adults and analyzed by gene expression profiling. Isolation: Effluxing CD161hi and non-effluxing CD161lo CD8+ TCM and TEM subsets were purified using magnetic bead separation and cell sorting to achieve >98% purity, as previously described (35). CD8+ T cells were positively selected using CD8 Microbeads (Miltenyi Biotec, Germany), loaded with Rh123 (Sigma, St. Louis, MO) and cultured for 30 min to allow Rh123 efflux, then labeled with fluorochrome-conjugated antibodies to CD4, CD16, TCRγδ, Vα24, CD8, CD95, CD62L and CD161. CD161hi and CD161lo TCM and TEM subsets were sort-purified on a FACS ARIA equipped with 405 nm, 488 nm and 633 nm lasers (BD Biosciences). CD161hi TCM and TEM subsets were identified as CD62L+/Rh123lo/CD161hi and CD62L-/Rh123lo/CD161hi events, respectively, in the CD4-/CD16-/TcRγδ-/Vα24-/CD8+/CD95+ population. CD161lo TCM and TEM subsets were identified as CD62L+/Rh123hi/CD161int/neg and CD62L-/Rh123hi/CD161int/neg events, respectively, in the CD4-/CD16-/TcRγδ-/Vα24-/CD8+/CD95+ population. Gene expression profiling: RNA was extracted from sort-purified subsets from 6 healthy individuals using the RNeasy Plus Minikit (Qiagen, Valencia, CA) and biotinylated, followed by generation of amplified cRNA for array hybridization using the Illumina TotalPrep RNA Amplification Kit (Applied Biosystems, Foster City, CA). Amplified biotinylated cRNA was then purified before quality control to ensure high quality cRNA was available for hybridization. Labeled cRNA was hybridized to Illumina WG-6 Expression BeadChips v3.0 (Illumina, San Diego, CA), which quantitate expression of 48,802 transcripts derived from the NCBI RefSeq (Build 36.2, Release 22) and UniGene databases (Build 199). BeadChips were washed before reading and image extraction, and then scanned on an Illumina BeadArray Reader. The resulting TIFF images were processed using GenomeStudio Gene Expression Module (GEM) software. Data quality was assessed using the Control Summary feature in GenomeStudio GEM. For a given analysis set, a GenomeStudio Probe-level Final Report was generated by combining the Sample Probe Profile and Control Probe Profile tables. The Final Report comprising the full dataset was initially processed using the Bioconductor package lumi by employing a background correction estimate and quantile normalization. A small adjustment (i.e. 20 counts) was made to the entire dataset to make all intensity signals non-negative and these values were log2-transformed. The dataset was initially filtered using the ‘shorth’ function of the Bioconductor package genefilter, resulting in retention of 31,084 of 48,802 original probes. Each pairwise comparison was further filtered by discarding probes whose signal intensity was less than a defined signal “noise floor” across all arrays in the data subset. This was achieved by calculating the median of the ‘negative control’ probe signals for each array, averaging these values, and setting the noise floor as 3 times this average. Differential gene expression was then determined using the Bioconductor package limma, and a false discovery rate (FDR) method applied to correct for multiple testing. Significant differential gene expression was defined by a log2 ratio > 0.585 (± 1.5-fold) and FDR (adjusted p value) < 0.05.
Project description:To explore the differences in miRNA profiles, naive CD4+CD62L+ helper T cells were sorted by magnetic cell sorting from spleens of female C57BL/6 mice and were induced to differentiate into Th1 or Th17 cells, then total RNA was extracted and miRNA-seq were conducted. The results showed that many microTNAs presented a different expression pattern between Th1 and Th17 cells, which prompted us to further study their roles in Th117 differenciation. miRNA profiles of Th0 and Th17 cells were generated by deep sequencing, in triplicate, using Illumina HiSeq 2500
Project description:Study the effect of PARP-14 and its activity on Th2 differentiation ChIP seq was performed on Th2 differentiated cells isolated from PARP-14 +/+ and PARP-14 -/- treated with or without PJ34
Project description:T-bet and GATA3 induce differentiation of CD4+ T-cells into Th1 or Th2 effectors. These exhibit a range of different properties but understanding of T-bet and GATA3 function is mostly limited to the murine Ifng and Il4/Il5/Il13 loci. We hypothesised that extending such analyses across the human genome would allow further insight into T-bet and GATA3 function. We have discovered that T-bet and GATA3 bind to multiple distal sites at a set of key immune regulatory genes. These sites display markers of functional elements, act as enhancers in reporter assays and are associated with lineage-specific expression regulated by T-bet and GATA3. Our approach also reveals that GATA3 is distributed at T-bet binding sites in Th1 cells and that T-bet directly activates its own expression. We propose that these aspects of T-bet and GATA3 function are critical for Th1/ Th2 differentiation and provide a model for the relationship between other lineage-specific regulators. ChIP was performed using antibody against T-bet in Th1 cells and against GATA3 in Th1 cells as well as Th2 cells. A sample of whole cell extract (WCE) from Th1 cells and Th2 cells was sequenced. Th1 WCE was used as the background to determine enrichment.
Project description:DNMT3a is a de novo DNA methyltransferase expressed robustly after T cell activation that regulates plasticity of CD4+ T cell cytokine expression. Here we show that DNMT3a is critical for directing early CD8+ T cell effector and memory fate decisions. While effector function of DNMT3a knockout T cells is normal, they develop more memory precursor and fewer terminal effector cells in a T cell intrinsic manner compared to wild-type animals. Rather than increasing plasticity of differentiated effector CD8+ T cells, loss of DNMT3a biases differentiation of early effector cells into memory precursor cells. This is attributed in part to ineffective repression of Tcf1 expression in knockout T cells, as DNMT3a localizes to the Tcf7 promoter and catalyzes its de novo methylation in early effector WT CD8+ T cells. This data identifies DNMT3a as a crucial regulator of CD8+ early effector cell differentiation and effector versus memory fate decisions. Examination of global genomic DNA methylation by MBD-seq in naïve CD8 T cells and CD8 T cells 8 days post Vaccinia-Ova infection, comparing OT1 TCR-Tg CD8 T cells isolated from WT and T cell conditional DNMT3a KO mice.
Project description:Wild-type Columbia (Col-0) and rcd1-1 seeds were sown on 1:1 peat:vermiculite mixture, stratified for 2 days and grown in controlled environment chambers (Weiss Bio1300; Weiss Gallenkamp, (http://www.weiss-gallenkamp.com/) with 12-h/12-h day/night cycle, temperature 22 °C/19 °C, relative humidity 70%/90%. 1-week old plants were transplanted into individual pots (5x5cm) and subirrigated twice a week. O3 experiments (6 hours of 350 nL L-1) were performed with 3-week old plants. Control and O3-treated plants (x-10 individuals) were collected at 0, 1, 2, 4, 8 and 24h after the start of the O3 treatment. The experiment was repeated 3 times, in addition to which a fourth identical repeat was used as the common reference RNA. cDNA synthesis, sample labeling, microarray hybridization, washing of the slides as well as image scanning were performed as described in Jaspers et al. (2009; PMID:19548978). The 50-mer oligo microarrays were identical to the Jaspers et al. 2009. In prerocessing, the 50mer probes were reannoated to TAIR9 with BLASTn algorithm. Data was analysed with linear mixed models using scripts in R.
Project description:Naive CD4+ CD62L+ CD25- T cells were differentiated under TH1 and TH2 conditions for 7 days, restimulated with anti-CD3 and anti-CD28 for 24h and sorted for IFN-gamma (TH1) and IL-4 (TH2) production using cytokine secretion assays.
Project description:The let-7 microRNA families are tumor suppressors often deregulated in cancer, yet the underlying mechanisms of let-7 disruption remain poorly understood. Neuroblastoma is defined in part by poor prognosis associated with genetic amplification of MYCN, itself a let-7 target. The let-7 biogenesis inhibitor LIN28B has been implicated as a critical regulator of MYCN ; however, here we show that LIN28B is dispensable for both MYCN protein expression and growth of MYCN amplified neuroblastoma cell lines despite robust de-repression of let-7 . We further report that amplified MYCN mRNA is a potent let-7 sponge that through exceptionally high expression defines a sub-set of self-sponging amplified competing endogenous RNA (aceRNA) and reconciles the dispensability of LIN28B . In addition, we observe frequent genomic loss of let-7 that inversely associates with MYCN- amplification, providing an explanation for common, yet unresolved amplification-independent patterns of chromosome loss. We thus propose a model whereby let-7 disruption by genetic loss, LIN28B expression, or aceRNA sponging is a unifying mechanism of neuroblastoma pathogenesis. Indeed, our data show that the majority of neuroblastomas have at least one let-7 disruption event and that genetic loss in non-MYCN amplified tumors marks decreased survival, further underscoring its importance. The inverse relationship between allelic loss and sponging of let-7 from highly expressed or amplified oncogenes may have broad implications for oncogenesis. Three cell lines, sampled in triplicate.
Project description:The let-7 microRNA families are tumor suppressors often deregulated in cancer, yet the underlying mechanisms of let-7 disruption remain poorly understood. Neuroblastoma is defined in part by poor prognosis associated with genetic amplification of MYCN, itself a let-7 target. The let-7 biogenesis inhibitor LIN28B has been implicated as a critical regulator of MYCN ; however, here we show that LIN28B is dispensable for both MYCN protein expression and growth of MYCN amplified neuroblastoma cell lines despite robust de-repression of let-7 . We further report that amplified MYCN mRNA is a potent let-7 sponge that through exceptionally high expression defines a sub-set of self-sponging amplified competing endogenous RNA (aceRNA) and reconciles the dispensability of LIN28B . In addition, we observe frequent genomic loss of let-7 that inversely associates with MYCN- amplification, providing an explanation for common, yet unresolved amplification-independent patterns of chromosome loss. We thus propose a model whereby let-7 disruption by genetic loss, LIN28B expression, or aceRNA sponging is a unifying mechanism of neuroblastoma pathogenesis. Indeed, our data show that the majority of neuroblastomas have at least one let-7 disruption event and that genetic loss in non-MYCN amplified tumors marks decreased survival, further underscoring its importance. The inverse relationship between allelic loss and sponging of let-7 from highly expressed or amplified oncogenes may have broad implications for oncogenesis. BE(2)C:MYCN-ORF cells transfected with siRNA and miRNA mimics