Project description:Our previous observation found CD27 negative MAIT cell subset is associated with T2D progression in overweight/obese patients. To identify the difference of functional properties between CD27 negative and positive MAIT subsets under obesity related T2D condition, we isolated circulating CD27+ or CD27- CD3+ CD161+ TCR Va7.2+ MAIT cells from PBMC of three diabetic obese patients and performed bulk RNA-seq based on Smart-seq2 protocol. By the comparison of CD27- and CD27+ MAIT cells, we found CD27- MAIT cell exhibit an increased mitochondrial mass and decreased response to bacterium transcriptional pattern compared to CD27+ MAIT cells in diabetic obese patients, indicating the imbalanced cell-bacteria interaction might contribute to T2D progression in overiweight/obese people.
Project description:To show the similarity among MAIT-iPSCs, hiPSCs and hESCs and the gradual change of global gene expression of reMAIT cells along with differentiation, this experiment was designed. MAIT cells, MAIT-iPSCs, hiPSCs, hESCs, MAIT cells, and reMAIT cells at the several differerent stages of differentiation were collected. Then, they were applied in this experiment.
Project description:MAIT cells (MAITs) represent an abundant T lymphocyte subset with unique specificity for microbial metabolites presented by the MHC-1b molecule, MR1. MAIT conservation along evolution indicates important, non-redundant functions, but their low frequency in mice has hampered their detailed characterization. Here, we performed a transcriptomic analysis of murine MAITs in comparison with NKT subsets and with mainstream T cells in spleen and peripheral organs of B6-MAIT/CAST mice expressing a Rorc-GFP transgene. MAIT and NKT cells have been FACS-sorted after tetramer staining (MR1:5-OP-RU Tet+ for MAIT, CD1d:PBS57Tet+ for NKT), and 1/17 subsetting based on the expression of Rorc.
Project description:To investigate gene expression profile of human liver MAIT cells from patients with biliary atresia, we isolated human liver MAIT cells from liver tissues of patients with biliary atresia and from adjacent non-tumor liver tissues of hepatoblastoma patients (as control) at the time of diagnosis, and subjected for bulk RNA sequencing.
Project description:Obesity underpins the development of numerous chronic diseases such as type II diabetes mellitus. It is well established that obesity negatively alters immune cell frequencies and functions. Mucosal Associated Invariant T (MAIT) cells are a population of innate T cells, which we have previously reported are dysregulated in obesity, with altered circulating and adipose tissue frequencies and a reduction in their IFN-gamma production, which is a critical effector function of MAIT cells in host defence. Hence there is increased urgency to characterise the key molecular mechanisms that drive MAIT cell effector functions, and to identify those which are impaired in the obesity setting. In this study, we found that MAIT cells significantly upregulate their rates of glycolysis upon activation in an mTORC1 dependent manner and this is essential for MAIT cell IFN-g production. Furthermore, we show that mTORC1 activation is dependent on amino acid transport via SLC7A5. In obese patients, using RNA sequencing, Seahorse analysis and a series of in vitro experiments, we demonstrate that MAIT cells isolated from obese adults display defective glycolytic metabolism, mTORC1 signalling and SLC7A5 amino acid transport. Collectively our data details the intrinsic metabolic pathways controlling MAIT cell cytokine production and highlights mTORC1 as an important metabolic regulator that is impaired in obesity, leading to altered MAIT cell responses. We report on MAIT cells isolated from lean and obese adults
Project description:Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that recognize microbial vitamin B metabolites and have emerging roles in infectious disease, autoimmunity, and cancer. Although MAIT cells are identified by a semi-invariant T cell receptor, their phenotypic and functional heterogeneity is not well understood. Here we present an integrated single cell transcriptomic analysis of over 76,000 human MAIT cells during acute and chronic antigen-specific activation with the MR1 ligand 5-OP-RU and non-specific TCR stimulation. We show that MAIT cells span a broad range of homeostatic, effector, helper, tissue-infiltrating, regulatory, and exhausted phenotypes, with distinct gene expression programs associated with CD4+ or CD8+ co-expression. During acute activation, MAIT cells rapidly adopt a cytotoxic phenotype characterized by high expression of GZMB, IFNG and TNF. In contrast, chronic stimulation induces heterogeneous states defined by proliferation, cytotoxicity, immune modulation, and exhaustion. We further demonstrate a FOXP3 expressing MAIT cell subset that phenotypically resembles conventional regulatory T cells. Moreover, scRNAseq-defined MAIT cell subpopulations were also detected in individuals recently exposed to Mycobacterium tuberculosis, confirming their presence during human infection. Our study provides the first comprehensive atlas of human MAIT cells in activation conditions and defines substantial functional heterogeneity, suggesting complex roles in health and disease.
Project description:In mice, contrary to conventional T cells, MAIT cells acquire a memory phenotype in the thymus in relation with Zbtb16 expression (Savage et al., 2008 ; Koay et al., 2016). To define phenotypic transcriptional signatures of MAIT subsets in the thymus, we analyzed by microarray the transcriptome of MAIT1 (MR1tet+RORgt+) and MAIT17 (MR1tet+RORgt+) as compared to conventional mature (TCRb+CD24lo) CD4+ and CD8+ single positive cells.
