Project description:Aire in medullary thymic epithelial cells plays an essential role in the negative selection through expression of broad arrays of tissue-restricted antigens. We asked whether Aire could also activate the expression of tissue-restricted antigens in cortical thymic epithelial cells. We established a semi-knockin strain of NOD-background mice expressing Aire under control of the promoter of β5t, a thymoproteasome expressed exclusively in the cortex. We extracted RNA from cortical thymic epithelial cells ectopically expressing Aire and hybridization was performed on Affymetrix. microarrays.
Project description:Aire is a transcriptional regulator that induces promiscuous expression of thousands of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We used Affymetrix microarrays to analyze the gene expression patterns of Aire expressing cells (mature mTECs and Thymic B cells) and compared them to control counterparts, namely immature mTECs, cortical Thymic epithelial cells and splenic B cells of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We used Affymetrix microarrays to analyze the gene expression patterns of Aire expressing cells (mature mTECs and Thymic B cells) and compared them to control counterparts, namely immature mTECs, cortical Thymic epithelial cells and splenic B cells.
Project description:Aire is a transcriptional regulator that induces promiscuous expression of thousands of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We used Affymetrix microarrays to analyze the gene expression patterns of Aire expressing cells (mature mTECs and Thymic B cells) and compared them to control counterparts, namely immature mTECs, cortical Thymic epithelial cells and splenic B cells of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We’ve used Assay for transposase-accessible chromatin using sequencing (ATAC-Seq) on the different thymic epithelial cell populations to assess chromatin accessibility around the Aire locus in these cells. Moreover, we’ve used the indexing-first chromatin immunoprecipitation (iChIP) technique to assess the occupancy of the Irf8 transcription factor in the Aire locus
Project description:Aire is a transcriptional regulator that induces promiscuous expression of thousands of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We used Affymetrix microarrays to analyze the gene expression patterns of Aire expressing cells (mature mTECs and Thymic B cells) and compared them to control counterparts, namely immature mTECs, cortical Thymic epithelial cells and splenic B cells of tissue-restricted antigen (TRA) genes in medullary thymic epithelial cells (mTECs). While the target genes of Aire are well characterized, the transcriptional programs regulating its own expression remain elusive. We’ve used Assay for transposase-accessible chromatin using sequencing (ATAC-Seq) on the different thymic epithelial cell populations to assess chromatin accessibility around the Aire locus in these cells. Moreover, we’ve used the indexing-first chromatin immunoprecipitation (iChIP) technique to assess the occupancy of the Irf8 transcription factor in the Aire locus
Project description:Aire in medullary thymic epithelial cells plays an essential role in the negative selection through expression of broad arrays of tissue-restricted antigens. We asked whether Aire could also activate the expression of tissue-restricted antigens in cortical thymic epithelial cells.
Project description:Promiscuous gene expression (pGE) of numerous self-antigens in thymic epithelial cells (TEC) enables the elimination of self-reactive T cells. The autoimmune regulator (Aire) is the only known molecular determinant driving pGE in the thymus but the existence of Aire-independent mechanisms has been inferred. Here, we analyzed the poly(A)+ transcriptome of TEC populations by RNA-sequencing (RNA-seq) in order to reveal differential features of Aire-induced vs. –independent pGE. We report an unanticipated effect of Aire deletion on the proliferation and differentiation of cortical TEC. Moreover, the RNA-seq data reveal the breath of Aire-induced and –independent pGE in medullary TEC (mTEC) subsets and the extent of thymic peripheral tissue representation. The results suggest that Aire-induced promiscuously expressed transcripts affect several functions with far reaching biological consequences in mTEC. High-throughput characterization of TEC transcriptomes will enable progress in understanding TEC biology and the establishment of self-tolerance. The mRNA profiles of cTEC, mTEClo and mTEChi from 6-8 week-old wild type (WT) and Aire-/- (KO) mice were generated by RNA-sequencing using Illumina HiSeq2000.