Project description:Umbilical cord blood (UCB) transplantation shows pro-angiogenic effect and contributes to symptom amelioration in animal models of cerebral infarction. OP9 is a stromal cell line used as feeder cells to promote hematoendothelial differentiation of embryonic stem cells. We co-cultured UCB 24hr with OP9 (i.e. OP9 preconditioning) and investigated its change in angiogenic properties and underlying mechanisms. Single cell RNA sequencing showed prominent phenotypic shift toward M2 in monocytic fraction of OP9 pre-conditioned UCB.
Project description:The OP9 coculture system is widely used to differentiate pluripotent stem cells into mesodermal lineages. We used single cell RNA sequencing to analyze differentiation trajectories and heterogeniety of differentiating pluripotent stem cells using the OP9 coculture system.
Project description:In the bone marrow B cell development occurs in initimate and essential association with stromal cells. Known effects of stromal cells on B cell development have been shown to be mediated through direct contact and by soluble factors produced by stromal cells. Our findings suggest that cell-nonautonomous Hh signaling may play an important role in B cell lymphopoiesis. We therefore interrogated OP9 stromal cells for Hh-dependent transcripts that may confer B lymphopoietic identity. We generated OP9 stromal cells deficient in Hh signaling through targeting the non-redundant, pathway-obligate GPCR Smoothened. OP9 cells were transduced with RNAi pLKO.1-Puro lentiviral particles expressing a scrambled control shRNA (NT) or shRNA targeting Smoothened (Smo-kd). RNA from stable NT and Smo-kd OP9 cells were isolated in triplicate and global changes in transcripts were analyzed using the Affymetrix Mouse Exon 1.0 ST gene chip.
Project description:In the bone marrow B cell development occurs in initimate and essential association with stromal cells. Known effects of stromal cells on B cell development have been shown to be mediated through direct contact and by soluble factors produced by stromal cells. Our findings suggest that cell-nonautonomous Hh signaling may play an important role in B cell lymphopoiesis. We therefore interrogated OP9 stromal cells for Hh-dependent transcripts that may confer B lymphopoietic identity.
Project description:Genetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. CD34+ cells of 2 healthy donors are cultured on a OP9-GFP or OP9-DLL1 feeder layer.
Project description:Comparison between ex vivo immature, mature and stimulated T cells and in vitro generated counterparts. The T cells generated in vitro were cultured on OP9-DL1 stroma supplied with growth factors.