Genome-wide analysis of TRA (tissue restricted antigen)-specific co-expression groups in mouse medullary thymic epithelial cells (mTECs)
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ABSTRACT: Analysis of gene co-expression patterns in TRA-specific medullary thymic epithelial cell (mTEC) subsets. The whole genome gene signatures of purified mTEC subsets respectively positive for the TRAs Gp2, Pdpn, Cea1, Gad1, Ins2, Tspan8 were compared to their corresponding TRA-negative mTEC subset control. Results provide the enriched and depleted gene expressions in the different subsets. Total RNA obtained from FACS isolated mTECs positive for the respective TRAs were compared to their TRA-negative mTEC subsets using specific antibodies (Pdpn, Gp2, Cea1, Tspan8) or reporter mice (Gad1, Ins2).
Project description:Analysis of gene co-expression patterns in TRA-specific medullary thymic epithelial cell (mTEC) subsets. The whole genome gene signatures of purified mTEC subsets respectively positive for the TRAs Gp2, Pdpn, Cea1, Gad1, Ins2, Tspan8 were compared to their corresponding TRA-negative mTEC subset control. Results provide the enriched and depleted gene expressions in the different subsets.
Project description:Analysis of the role of Hipk2 in regulating gene expression in medullary thymic epithelial cells. The whole genome gene signatures of purified mTEC subsets (CD80 low, CD80 high) from TEC-specific Hipk2 knockout mice were compared to mating wildtype control mice (floxed, Cre-). Results provide the up- or down-regulated genes, affected by the Hipk2 gene knockout. Total RNA obtained from isolated CD80 low and CD80 high mTECs of TEC-specific Hipk2 knockout mice compared to control mice mTEC subsets
Project description:The capability of T cells for discrimination between self and non-self peptides is based on rigorous negative selection of developing thymocytes by medullary thymic epithelial cells (mTECs). The mTECs purge autoreactive T cells by expression of cell-type specific genes referred to as tissue-restricted antigens (TRAs), therefore, the expression patterns of TRA genes can help understand development of mTECs and the regulatory mechanism during the development. We use single-cell RNA-sequencing to resolve patterns of TRA expression, and to elucidate how these patterns are changed during mTEC development. Thymi were collected from 2 and 4 week-old wild-type male and female mice. The mTEC suspension obtained from sorting was loaded onto the Fluidigm C1 platform using mediumsized capture chips (10-17m cells). External RNA Control Consortium (ERCC) spike-ins (Ambion, Life Technologies) were included in the lysis buffer. Reverse transcription and cDNA preamplification were performed using the SMARTer Ultra Low RNA kit (Clontech). The cDNA libraries for sequencing were prepared and libraries from 96 single cells were pooled and subsequently purified; pooled samples were sequenced on an Illumina HiSeq 2500 instrument.
Project description:Cellular interactions in the thymus play an essential role in ensuring the development of a self-tolerant T cell repertoire. Medullary thymic epithelial cells (mTECs) contribute to tolerance by expressing and presenting tissue-restricted antigens (TRA) so that developing T cells can assess the self-reactivity of their antigen receptors prior to leaving the thymus. This has largely been studied in the context of autoimmune regulator (Aire) dependent TRA expression in mature mTECs. Yet, mTECs are a heterogeneous population of cells that differentially express unique pools of TRA, and whether mTEC subsets induce distinct autoreactive T cell fates remains unclear. Here we attribute unique roles for mTEC subsets in directing distinct mechanisms of T cell tolerance that significantly impact infection and tumor control. These results have important implications in the design of effective therapeutic approaches that aim to modulate the function of self-reactive T cells.
Project description:Comparative gene expression profiling of thymocytes at the DP, CD4 SP and CD8 SP stage derived from FoxN1-Gpr177 mice (FoxN1-Cre mediated deletion of (Exon3 of) Gpr177/Wtls) or C57Bl/6N mice as comparison. Objective was to test the influence of TEC-secreted Wnt ligands on the transcriptome of thymocytes at the respective developmental stages. Total RNA extracted from FACS-sorted primary mouse thymocytes. CD4/8 double positive (DP) thymocytes, CD4 single positive (CD4 SP) thymocytes and CD8 single positive (CD8 SP) thymocytes were FACS-sorted from conditional knock-out mice (FoxN1-Gpr177) and C57Bl/6N mice as comparison.
Project description:The deficiency of Aire, a transcriptional regulator whose defect results in the development of autoimmunity, is associated with reduced expression of tissue-restricted self-Ags (TRAs) in medullary thymic epithelial cells (mTECs). Although the mechanisms underlying Aire-dependent expression of TRAs need to be explored, the physical identification of the target(s) of Aire has been hampered by the low and promiscuous expression of TRAs. We have tackled this issue by engineering mice with augmented Aire expression. Integration of the transcriptomic data from Aire-augmented and Aire-deficient mTECs revealed that a large proportion of so-called Aire-dependent genes, including those of TRAs, may not be direct transcriptional targets downstream of Aire. Rather, Aire induces TRA expression indirectly through controlling the heterogeneity of mTECs, as revealed by single-cell analyses. In contrast, Ccl25 emerged as a canonical target of Aire, and we verified this both in vitro and in vivo. Our approach has illuminated the Aire?s primary targets while distinguishing them from the secondary targets.
Project description:Insm1, encoding a zinc finger protein, is expressed specifically in neuroendocrine cells. Recent study showed the first evidence of Insm1 expression in medullary thymic epithelial cells (mTEC). Here we investigated the expression and function of Insm1 in mTEC. Mutation of Insm1 resulted in decreased proportion of mTEChi although normal development of other types of thymic cells. We detected altered expression of a subset of tissue-restricted antigens (TRAs) and mild decreased expression of Aire and Fezf2 in Insm1 mutant mTEC. We further showed that Insm1 recognizes a DNA sequence which is similar to the CCCTC-Binding factor (CTCF) binding motif. Mutation of Insm1 altered CTCF binding genome widely and thus the expression of genes. In nude mice transplanted with Insm1 mutant thymus, autoimmune responses were observed in multiple peripheral tissues. In thymus specific Insm1 mutant mice, we detected decreased induction of regulatory T (Treg) cells in the thymus, obvious lymphocytes infiltration and autoimmune antibody reaction in several peripheral tissues. In thymic epithelial cells specific Insm1 overexpression mice, we detected enlarged mTEC proportion and increased expression of mTEC specific genes. Thus, we suggest that Insm1 is a novel regulator of mTEC function and autoimmunity.
Project description:Insm1, encoding a zinc finger protein, is expressed specifically in neuroendocrine cells. Recent study showed the first evidence of Insm1 expression in medullary thymic epithelial cells (mTEC). Here we investigated the expression and function of Insm1 in mTEC. Mutation of Insm1 resulted in decreased proportion of mTEChi although normal development of other types of thymic cells. We detected altered expression of a subset of tissue-restricted antigens (TRAs) and mild decreased expression of Aire and Fezf2 in Insm1 mutant mTEC. We further showed that Insm1 recognizes a DNA sequence which is similar to the CCCTC-Binding factor (CTCF) binding motif. Mutation of Insm1 altered CTCF binding genome widely and thus the expression of genes. In nude mice transplanted with Insm1 mutant thymus, autoimmune responses were observed in multiple peripheral tissues. In thymus specific Insm1 mutant mice, we detected decreased induction of regulatory T (Treg) cells in the thymus, obvious lymphocytes infiltration and autoimmune antibody reaction in several peripheral tissues. In thymic epithelial cells specific Insm1 overexpression mice, we detected enlarged mTEC proportion and increased expression of mTEC specific genes. Thus, we suggest that Insm1 is a novel regulator of mTEC function and autoimmunity.
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)
Project description:The goal of the study was to sequence mRNA expression from sorted medullary thymic epithelial cell (mTEC) subsets in inducible Aire-CreERT2.R26-Stopfl-tdTomato lineage tracing mice after a pulse chase. Four cell subsets were sorted 7 days after a single 2mg pulse of tamoxifen administered by oral gavage. 4 biological replicates (1,2,3,4) were collected derived from 12 pooled thymi per replicate. From the DAPI-;CD45-;EpCAM+ TEC pool, cells were sorted as: pre-Aire (MHCIIlo;RFP-), early-Aire (MHCIIhi;RFP-), late-Aire (MHCIIhi;RFP+), and post-Aire (MHCIIlo;RFP+). The data were used to identify differentially expressed genes across the four mTEC subsets to examine mTEC heterogeneity and identify novel mTEC subpopulations.