Transcriptional and post-transcriptional activity of thymocytes adhered to Aire mutant mTEC cells

Abstract

The fellow will study the transcriptional profile involving mRNAs and miRNAs of thymocytes that physically interact with Aire wild-type (wt) or Aire mutant mTECs cells (adhesion mTECs-thymocytes in vitro). As discussed in the thematic project, the interaction between thymocytes and epithelial thymic cells (TECs) is essential for the development of these two cell types. To test this hypothesis, we will use the mTEC-thymocyte adhesion model system (in vitro co-culture) to study its effect on the modulation of gene expression. As we have already seen that this type of adherence interferes with the mTEC transcriptome (Pezzi et al 2016), we raised the possibility that this may also influence the transcriptional activity of thymocytes. We will test whether mutations in the Aire gene associated with the APS1 syndrome, but induced by the CRISPR-Cas9 system (mutations of the human Aire gene in the SAND and PHD1 domains) in mTECs, may influence adherence and, consequently, the transcriptional activity of thymocytes. Once with the expression data from thymocytes that adhered to Aire wt or Aire mutant mTEC cells, we will investigate the interaction networks between these two RNA species, that is, the miRNAs-mRNA interactions that ultimately control gene expression at post-transcriptional level. The results will be useful to assess whether there is an association between Aire mutations in mTECs with the gene activity of thymocytes that adhere to these cells, which is also important for the establishment of immunological tolerance. (AU)