GSE193927
Insm1 regulates the expression of thymic tissue-restricted antigens and the immune tolerance [RNA-seq]
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. Overall design: mRNA profiles of wt and Insm1-mutate mouse medullary thymic epithelial cells