Deletion of PKBalpha/Akt1 affects thymic development
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE7875 | GEO | 2007/10/03
SECONDARY ACCESSION(S): PRJNA99903
REPOSITORIES: GEO
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Project description:The thymus constitutes the primary lymphoid organ for the majority of T cells. The phosphatidyl-inositol 3 kinase (PI3K) signaling pathway is involved in lymphoid development. Defects in single components of this pathway prevent thymocytes from progressing beyond early T cell developmental stages. Protein kinase B (PKB) is the main effector of the PI3K pathway. To determine whether PKB mediates PI3K signaling in early T cell development, we characterized PKB knockout thymi. Our results reveal a significant thymic hypocellularity in PKBalpha-/- neonates and an accumulation of early thymocyte subsets in PKBalpha-/- adult mice. The latter finding is specifically attributed to the lack of PKBalpha within the lymphoid component of the thymus. Microarray analyses show that the absence of PKBalpha in early thymocyte subsets modifies the expression of genes known to be involved in pre-TCR signaling, in T cell activation, and in the transduction of interferon-mediated signals. This report highlights the specific requirements of PKBalpha for thymic development. Experiment Overall Design: Early thymocyte subsets (DN3 and ISP8) were sorted by FACS from 4 PKBalpha-/- / PKBalpha+/+ mouse littermate pairs. The same number of DN3 or ISP8 cells was sorted (7 000 to 25 000 cells) within a PKBalpha-/- / PKBalpha+/+ pair. Four replicates per condition were then analysed (4xPKBalpha-/- DN3, 4xPKBalpha+/+ DN3, 4xPKBalpha-/- ISP8, 4xPKBalpha+/+ ISP8). Total RNA was extracted using PicoPureTM RNA isolation kit (Arcturus, Sunnyvale, CA, USA) and RNA quality was controlled using the 2100 Bioanalyser (Agilent Technologies, Santa Clara, CA, USA). Total RNA was amplified and labeled using the Affymetrix 2-cycle 3â labelling kit according to manufacturerâs instructions. After fragmentation, 10 ug cRNA was hybridised to mouse genome 430 2.0 GeneChips (Affymetrix, Santa Clara, CA). The supplementary file represents the expression values estimated using the GC-RMA function provided by Refiner 3.1 (Genedata, Basel, Switzerland) for each of the samples.
2008-06-15 | E-GEOD-7875 | biostudies-arrayexpress
Project description:The thymic microenvironment is essential for proper differentiation and selection of thymocytes.Thymic involution in aged mice results in decreased T cell output and immune function. Here we use gene expression profiling of FACS sorted thymic stromal subsets to identify molecular mediators of thymocyte: stromal cell interactions, as well as gene expression changes thymic stromal subsets during early stages of thymic involution . We used microarrays to analyze gene expression differences between thymic stromal subsets from male C57BL/6J mice 1, 3, and 6 months of age. Thymic stromal subsets (cTEC, mTEClo, mTEChi, Sirpa-DC, Sirpa+DC, and fibroblasts) were isolated from two 1-, 3-, and 6- month old male C57BL/6J mice. After enzymatic digestion of the thymi, the stromal cells were FACS purified, and RNA was extracted, amplified, labeled and hybridized to Affymetrix mouse 430 2.0 arraysarrays. Raw data were uploaded to Gene Expression Commons for normalization. Both raw CEL and normalized datasets from the 36 samples are included. A model within Gene Expression Commons has been created for analyses/comparisons of these datasets, along with previously reported thymocyte subset datasets. The model within Gene Expression Commons thus contains 6 thymic stromal populations, each from mice 1, 3, and 6 months of age, with duplicates for each datset.
2014-09-12 | E-GEOD-56928 | biostudies-arrayexpress
Project description:The thymic microenvironment is essential for proper differentiation and selection of thymocytes.Thymic involution in aged mice results in decreased T cell output and immune function. Here we use gene expression profiling of FACS sorted thymic stromal subsets to identify molecular mediators of thymocyte: stromal cell interactions, as well as gene expression changes thymic stromal subsets during early stages of thymic involution . We used microarrays to analyze gene expression differences between thymic stromal subsets from male C57BL/6J mice 1, 3, and 6 months of age.
2014-09-12 | GSE56928 | GEO
Project description:Thymomas are one of the most rarely diagnosed malignancies. To better understand its biology and to identify therapeutic targets, we performed next-generation RNA sequencing. The RNA was sequenced from 13 thymic malignancies and 3 normal thymus glands. Validation of microRNA expression was performed on a separate set of 35 thymic malignancies. For cell-based studies, a thymoma cell line was used. Hierarchical clustering revealed 100% concordance between gene expression clusters and WHO subtype. A substantial differentiator was a large microRNA cluster on chr19q13.42 that was significantly overexpressed in all A and AB tumors and whose expression was virtually absent in the other thymomas and normal tissues. Overexpression of this microRNA cluster activates the PI3K/AKT/mTOR pathway. Treatment of a thymoma AB cell line with a panel of PI3K/AKT/mTOR inhibitors resulted in marked reduction of cell viability. A large microRNA cluster on chr19q13.42 is a transcriptional hallmark of type A and AB thymomas. Furthermore, this cluster activates the PI3K pathway, suggesting the possible exploration of PI3K inhibitors in patients with these subtypes of tumor. This work has led to the initiation of a phase II clinical trial of PI3K inhibition in relapsed or refractory thymomas. 13 thymic malignancies and 3 Normal Thymus RNA-Sequenced in triplicate
2016-04-06 | E-GEOD-79978 | biostudies-arrayexpress
Project description:Over activation of the aryl hydrocarbon receptor (AhR) by TCDD results ampng other phenotypes in severe thymic atrophy accompanied by immunosuppression. The link between thymic atrophy, skewed thymocyte differntiation and immunosuppression is still not fully resolved. This study investigates the TCDD elicted exprssion changes in the ET, cortical thymus epithelial cell line. Keywords: TCDD, AhR, thymic epithelial cells, thymic involution, thymus atrophy
2008-12-31 | GSE10168 | GEO
Project description:The thymus is a primary lymphoid organ that plays an essential role in T lymphocyte maturation and selection during development of one arm of the mammalian adaptive immune response. Although transcriptional mechanisms have been well documented in thymocyte development, co-/post-transcriptional modifications are also important but have received less attention. Here, we demonstrate that the RNA alternative splicing factor MBNL1, which is sequestered in nuclear RNA foci by C(C)UG short tandem repeat expansions in myotonic dystrophy (DM), is essential for normal thymus development and function. Mbnl1 129S1 knockout mice develop postnatal thymic hyperplasia with thymocyte accumulation. Transcriptome analysis indicates numerous gene expression and RNA mis-splicing events, including transcription factors from the TCF/LEF (T-cell factor/lymphoid enhancer factor) family. CNBP, the gene affected in DM type 2 (DM2), is coordinately expressed with MBNL1 in the developing thymus and DM2 CCTG expansions induce similar transcriptome alterations in DM2 blood, which thus serve as disease-specific biomarkers.
2020-03-05 | GSE138691 | GEO
Project description:Despite their key role in immunity our understanding of primary and secondary lymphoid stromal cell heterogeneity and ontogeny remains limited. Here, using genome-wide expression profiling and phenotypic and localization studies, we identify a functionally distinct subset of BP3-PDPN+PDGFRβ+/α+CD34+ stromal adventitial cells in both lymph nodes and thymus that is located within the perivascular niche surrounding PDPN-PDGFRβ+/α-Esam-1+ITGA7+ pericytes. In re-aggregate organ grafts adult CD34+ adventitial cells gave rise to multiple thymic and lymph node mesenchymal subsets including pericytes, FRC-, MRC- and FDC-like cells, the development of which was lymphoid environment dependent. During thymic ontogeny pericytes developed from a transient population of BP3-PDPN+PDGFRβ+/α+CD34-/lo anlage-seeding progenitors that subsequently up-regulated CD34 and we provide evidence suggesting that similar embryonic progenitors give rise to lymph node mesenchymal subsets. These findings extend the current understanding of lymphoid mesenchymal cell heterogeneity and highlight a role of the CD34+ vascular adventitia as a potential ubiquitous source of lymphoid stromal precursors in postnatal tissues. To comprehensively study the differences and similarities between mesenchymal stromal subsets in the thymus and lymph nodes, global gene expression analysis was performed on sorted PDPN-, BP-3-PDPN+ and BP-3+PDPN+ PDGFRb+ lymph node mesenchymal cells (LNMC) as well as PDPN- and BP-3-PDPN+ PDGFRb+ thymic mesenchymal cells (TMC) from 2 w old mice by microarray. Total RNA was prepared from TMC and LNMC (pooled inguinal, brachial and axillary LN) subsets sorted from 3 (TMC) and 10-11 (LNMC) 2 weeks old mice per experiment. Isolated RNA from 3 individual experiments was amplified and prepared for hybridization to the Affymetrix Mouse Gene 1.1 ST Array at a genomics core facility: Center of Excellence for Fluorescent Bioanalytics (KFB, University of Regensburg, Germany)
2016-03-03 | E-GEOD-76974 | biostudies-arrayexpress
Project description:BACKGROUND: The thymus is a central lymphoid organ, in which bone marrow-derived T cell precursors undergo a complex process of maturation. Developing thymocytes interact with thymic microenvironment in a defined spatial order. A component of thymic microenvironment the thymic epithelial cells (TEC) are crucial for the maturation of T-lymphocytes because the secretion of extracellular matrix compounds, thymic hormones and cytokines and also by cell-cell contacts which can be mediated by extracellular matrix compounds and its receptors, integrins. There is evidence that extracellular matrix molecules play a fundamental role in localizing the different thymocyte stages in the thymus. The interaction between alpha5beta1 (CD49e/CD29; VLA-5) and fibronectin is essential for thymocyte adhesion. Previous results from our laboratory have shown that adhesion of thymocytes to cultured TEC line is enhanced in the presence of fibronectin. And we also demonstrated that anti-VLA-5 antibody when applied to growing TEC prior to the co-culturing with thymocytes, significantly prevented their adhesion to the epithelial. RESULTS: Herein, we studied the role of integrin alpha5 subunit in thymocyte and thymic epithelial cell interactions. We investigate the in vitro effects of silencing alpha5 integrin subunit in human thymic epithelial cell line by RNA interference. After silence a great deal of interest has arisen on intracellular signaling due the absence of alpha5 integrin subunit silence. The expression profile using cDNA microarrays of alpha5 subunit silenced cells showed 131 genes differential expression. Our data showed downregulation in two genes with cell adhesion function: neuronal cell adhesion molecule (NrCAM) and Activin receptor-like kinase 1 gene and in genes related with integrin pathway like, Phosphatidylinositol-4-phosphate 5-kinase, Phospholipase C gamma1 and SHC (Src homology 2 domain containing) transforming protein 1. We also assessed the effect of the loss of alpha5beta1 expression on TEC-thymocytes interaction and ours experiments confirm that alpha5beta1 contribute to adhesion rate. CONCLUSION: Conjointly, our data reinforce the importance of VLA-5 in TEC thymocyte interactions in the process of thymocyte differentiation and we hypothesize a decrease in stress fibers due absence of alpha5 integrin subunit and a compensatory pathway because of downregulation of neuropilin-2, vascular endothelial growth factor and plexin A.
2010-02-28 | GSE18116 | GEO
Project description:Programming T lymphocytes to distinguish self from non-self is a vital, multi-step process arising in the thymus. Signalling through the pre-T cell receptor (preTCR), a CD3-associated heterodimer comprising an invariant pTα chain and a clone-specific β chain, constitutes a critical early checkpoint in thymocyte development within the αβ T-cell lineage. Recent work demonstrates that preTCRs arrayed on double negative (DN) thymocytes, like αβ TCRs appearing on double positive (DP) thymocytes, ligate peptides bound to MHC molecules (pMHC) on thymic stroma but via a different molecular docking strategy. Here we show the consequences of those distinctive interactions for thymocyte progression, using synchronized fetal thymic progenitor cultures differing in the presence or absence of pMHC on support stroma, determining single cell transcriptomes at key thymocyte developmental transitions. Although MHC negative stroma fosters αβ T lymphocyte differentiation, the absence of pMHC-preTCR interplay leads to deviant thymocyte transcriptional programming associated with de-differentiation. Highly proliferative DN and DP subsets with antecedent characteristics of T cell lymphoblastic and myeloid malignancies emerge. Thus, in addition to fostering β chain repertoire broadening for subsequent αβ TCR utilization, preTCR-pMHC interaction limits cellular plasticity to facilitate normal thymocyte differentiation and proliferation that, if absent, introduces significant developmental vulnerabilities.
2022-10-18 | GSE186049 | GEO
Project description:Human T lymphogenesis includes emergence, migration and thymus-seeding of T lymphoid precursor, followed by T-lymphocytes commitment in thymus, which are largely unknown. Here, we perform single-cell RNA sequencing using cells isolated from human hemogenic/hematopoietic sites such as aorto-gonad-mesonephros (AGM), liver, and thymic primordia spanning embryonic and fetal stages. The transcriptional atlas of thymic primordia illustrates the cellular trajectory of early T-lymphocyte development. Further, thymic seeding progenitors in liver and unique T lymphoid progenitors in AGM at CS14, are first unveiled. We also reveal the stepwise-specification of thymic epithelial cells，and the potential cell-cell interactions between T-lymphocyte progenitors and stromal cells during thymus organogenesis. Our data provide new insights into T lymphogenesis, which prospectively directs the efficient regeneration of T- lymphocytes from pluripotent stem cells
2019-10-09 | GSE133341 | GEO