Project description:We sequenced T cells from 2 control and 2 Crohn's disease patients We determined that in human Th17 T cells are highly enriched in the IEL compartment We identified discrete populations of CD8 and CD4 T cells, which are differently represented in IEL and LP
Project description:The intestinal mucosa harbors the largest accumulation of T lymphocytes in the body. While these T cells play an important role in immune homeostasis, they are also implicated in triggering and maintaining pathological intestinal inflammation. In humans they are poorly characterised, and even mouse transcriptomes have been reported for only a few individual cell types, many of which lack direct human equivalents. Using expression microarrays on T cells isolated from ileal biopsies and in silico analysis, we present here an unbiased, transcriptome-wide view of function in T cell subpopulations of the healthy human intestine and delineate signalling pathways that are distinct from those seen in peripheral blood T cells. Paired blood and intestinal biopsies from 6 age/sex matched healthy human subjects. Intestinal biopsies processed to release intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL). All samples then used to generate T effector memory (Tem) cells of CD4+ and CD8+ subsets by flow sorting. 6 individuals; 3 cell sources per individual (blood, LPL, IEL); 2 Tem subsets per cell source (CD4+ and CD8+). 36 arrays in total
Project description:Mouse small intestine intraepithelial lymphocytes (IEL) that express a ab TCR and CD8aa homodimers are an enigmatic T cell subset, as their specificity and in vivo function remain to be defined. To gain insight into the nature of these cells, we performed global gene expression profiling using microarray analysis, combined with PCR and flow cytometry to determine the level of expression of selected genes. Using these methods, TCR ab+ CD8aa IEL were compared to their TCR ab+ CD8b+ and TCR gd+ counterparts. Experiment Overall Design: In this study, the three IEL populations were isolated by cell sorting from a pool of IELs from 20 mice. RNA from each IEL subset was used to probe one microarray. A replicate experiment was performed on a seperate occasion using a new pool of 20 mice and three additional microarrays were used.
Project description:To examine how the cluster composition of CD8aa IEL and their transcriptomic signatures were affected by LRF disruption, single-cell gene expression of CD8aa IEL from control (Cd4 Cre–Lrffl/fl) and CD8aa splenocytes from LRF KO (Cd4 Cre+Lrffl/fl ) mice were determined by scRNAseq.
Project description:The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that buoys intestinal immune responses. AHR induces its own negative regulator, the AHR repressor (AHRR). Here we show that AHRR is vital to sustain intestinal intraepithelial lymphocytes (IEL). Fewer IEL of all types were present in the absence of AHRR. Single cell RNA sequencing (scRNAseq) revealed an oxidative cell stress profile in Ahrr–/– IEL. Ahrr deficiency unleashed AHR-induced expression of CYP1A1, an oxidative enzyme that generates reactive oxygen species; this resulted in elevated intracellular content of reactive oxygen species, lipid peroxidation and ferroptosis in Ahrr–/– IEL. Dietary supplementation with selenium or Vitamin-E (Vit-E) to restore redox homeostasis rescued Ahrr–/– IEL. Loss of IEL in Ahrr deficient mice caused susceptibility to Clostridium difficile infection and dextran sodium sulfate-induced colitis. We conclude that AHR signaling must be tightly regulated to prevent oxidative stress and ferroptosis of IEL to preserve intestinal immune responses.
Project description:Mouse small intestine intraepithelial lymphocytes (IEL) that express a ab TCR and CD8aa homodimers are an enigmatic T cell subset, as their specificity and in vivo function remain to be defined. To gain insight into the nature of these cells, we performed global gene expression profiling using microarray analysis, combined with PCR and flow cytometry to determine the level of expression of selected genes. Using these methods, TCR ab+ CD8aa IEL were compared to their TCR ab+ CD8b+ and TCR gd+ counterparts. Keywords: Cell type comparison
Project description:Intestinal intraepithelial T lymphocytes (T-IEL) patrol the single layer of epithelial cells lining the gut, and consist of both induced T-IEL, derived from systemic antigen-experienced lymphocytes, and natural IEL, that are developmentally targeted to the intestine. To gain functional insights into these enigmatic cells, we used high-resolution quantitative mass spectrometry to investigate the proteomic landscape of the main T-IEL populations in the gut. Comparing the proteomes of induced T-IEL, tissue-resident memory TCRαβ+ CD8αβ+ cells and natural TCRγδ+ CD8αα+ and TCRαβ+ CD8αα+ T-IEL, with naive CD8+ T cells from lymph nodes reveals striking similarities between T-IEL subsets and the dominant effect of the gut environment on T-IEL phenotypes. Analysis of copy numbers/cell of >7000 proteins provides new understanding of the differences in composition of T cell antigen receptor signal transduction pathways in T-IEL versus conventional T cells and reveals skewing of the metabolic machinery towards an exhausted T cell phenotype adapted to the intestinal environment. This study provides a resource for exploring and understanding how multiple inputs are integrated into T-IEL function.
Project description:Intestinal intraepithelial lymphocytes (IEL) are an abundant population of tissue-resident T cells that protect the gut from pathogens and maintain intestinal homeostasis. The cytokine IL-15 is trans-presented by epithelial cells to IEL in complex with the IL-15 receptor α chain (IL-15Rα) and plays essential roles both in maintaining IEL homeostasis, and in inducing IEL activation in response to epithelial stress. When overproduced, IL-15 is a key driver of the gluten-induced enteropathy Coeliac disease, through cytotoxic activation of IEL. To better understand how IL-15 directly regulates both homeostatic and inflammatory functions of IEL, we performed quantitative proteomics of IL-15/Rα-stimulated murine IEL, sorted into their 3 main subpopulations, TCRγδ CD8αα, TCRαβ CD8αβ and TCRαβ CD8αα expressing IEL. The data reveal that high IL-15/Rα stimulation licenses cell cycle activation, upregulates the biosynthetic machinery in IEL, increases mitochondrial respiratory capacity and induces expression of cell surface immune receptors and adhesion proteins that potentially drive IEL activation.