Project description:Mucosal-associated invariant T (MAIT) cells are a subpopulation of T lymphocytes that respond to microbial metabolites. We performed single-cell RNA sequencing and metabolic analyses in MAIT cell subsets in thymus and peripheral tissues from mice and humans to define the heterogeneity and developmental path of these innate-like lymphocytes. We show that the predominant mouse subset, which produces IL-17 (MAIT17), and the subset that produces IFN (MAIT1), have greatly different transcriptomes and metabolic states in the thymus and periphery. A subset has a transcriptome similar to circulating lymphocytes, and in mice these are found in recent thymic emigrants, suggesting partially mature cells emigrate from the thymus. Human MAIT cells are predominantly MAIT1 cells, but have a different metabolism from naïve CD8 T cells with increased fatty acid uptake and storage. Although mouse and human subsets are similar in thymus, in the periphery they are divergent, likely reflecting environmental and genetic differences.
Project description:Mucosal-associated invariant T (MAIT) cells are a subpopulation of T lymphocytes that respond to microbial metabolites. We performed single-cell RNA sequencing and metabolic analyses in MAIT cell subsets in thymus and peripheral tissues from mice and humans to define the heterogeneity and developmental path of these innate-like lymphocytes. We show that the predominant mouse subset, which produces IL-17 (MAIT17), and the subset that produces IFN (MAIT1), have greatly different transcriptomes and metabolic states in the thymus and periphery. A subset has a transcriptome similar to circulating lymphocytes, and in mice these are found in recent thymic emigrants, suggesting partially mature cells emigrate from the thymus. Human MAIT cells are predominantly MAIT1 cells, but have a different metabolism from naïve CD8 T cells with increased fatty acid uptake and storage. Although mouse and human subsets are similar in thymus, in the periphery they are divergent, likely reflecting environmental and genetic differences.
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.
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: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