The ability of the immune system to avoid autoimmune disease relies on tolerization of thymocytes to self-antigens whose expression and presentation by thymic medullary epithelial cells (mTECs) is controlled predominantly by Aire at the transcriptional level and possibly regulated at other unrecognized levels. Aire-sensitive gene expression is influenced by several molecular factors, some of which belong to the 3'end processing complex, suggesting they might impact transcript stability and levels through an effect on 3'UTR shortening. We discovered that Aire-sensitive genes display a pronounced preference for short-3'UTR transcript isoforms in mTECs, a feature preceding Aire's expression and correlated with the preferential selection of proximal polyA sites by the 3'end processing complex. Through an RNAi screen and generation of a lentigenic mouse, we found that one factor, Clp1, promotes 3'UTR shortening associated with higher transcript stability and expression of Aire-sensitive genes, revealing a post-transcriptional level of control of Aire-activated expression in mTECs.
All RNAseq and microarray data are deposited in the NCBI Gene Expression Omnibus database (GEO).
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: Mice were housed, bred and manipulated in specific-pathogen-free conditions at Cochin Institute according to the guidelines of the French Veterinary Department and under procedures approved by the Paris-Descartes Ethical Committee for Animal Experimentation (decision CEEA34.MG.021.11 or APAFIS #3683 No 2015062411489297 for lentigenic mouse generation)
© 2020, Guyon et al.
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