Project description:iNKT cells are a T lymphocyte subset displaying an innate effector phenotype that is acquired through a thymic developmental program controlled by microRNAs (miRNAs). iNKT cells lacking all miRNAs by the deletion of Dicer (Dicer KO) are markedly reduced and display a complete maturation block. In this study, we sought to gain insight into the miRNA-regulated genetic program required for iNKT cell development. By systemic analysis, we identified transcripts differentially expressed between thymic WT or Dicer KO iNKT cells and targeted by the iNKT cell-specific miRNAs. TGF-βRII, a molecule critically implicated in iNKT cell maturation, was found upregulated in Dicer KO iNKT cells together with increased TGF-β-dependent signaling. miRNAs belonging to the paralog miR-106a~363, miR-106b~25 and miR-17~92 clusters were predicted to target TGF-βRII mRNA during iNKT cell development. Thymic iNKT cells lacking all three miRNA clusters displayed both increased TGF-βRII expression and signaling and a maturation block, recapitulating those found in Dicer KO iNKT cells. Consistently, inhibition of TGF-β-dependent signaling in the absence of miRNAs, by crossing TGF-βRII KO and Dicer KO mice, rescued iNKT cell maturation. Collectively, our results highlight a fundamental requirement of the modulation of TGF-β-dependent signaling by miRNAs for iNKT cell development
Project description:To understand the mechanisms through which JunB regulates Tregs-mediated immune regulation, we examined the global gene expression profiles in the JunB WT and KO Tregs by performing RNA sequencing (RNA-seq) analysis.
Project description:Deletion of Uhrf1 resulted in stage 1-specific defects during iNKT cell development. To investigate the molecular mechanism, we sorted WT and Uhrf1-KO stage 1 iNKT cells and performed RNA-seq. By comparing gene expression profile, we found metabolic defects in Uhrf1-KO stage 1 iNKT cells. The expression of CD71 (Tfrc), two subunits of CD98 (Slc3a2 and Slc7a5) and Glut3 (Slc2a3) was reduced in stage 1 iNKT cells. Besides, the downstream pathways of AKT-mTOR axis were significantly reduced. Collectively, our results suggest that Uhrf1 is required for iNKT cell development by regulating the Akt-mTOR signaling pathway. We first sorted WT and Uhrf1-KO stage 1 iNKT cells, extracted the mRNA and performed RNA-seq. We then analyzed the differentially expressed genes and performed KEGG pathway analysis. We used RT-PCR to verify the expression of the key nutrient related genes (Tfrc, Slc3a2, Slc7a5 and Slc2a3) and used flow cytometry to test the protein level of metabolic related molecules. Besides, we also analyzed the expression of genes of mTOR downstream pathways to demonstrate that Uhrf1 mediated AKt-mTOR axis regulates iNKT cell development.