Project description:To study the regulation of candidate genes from our study in human cells, we analyzed CD4+ T cells from blood and CSF of MA patients and age and sex matched idiopathic intracranial hypertension controls We analyzed 40845 cells in control blood, 807 cells in control CSF, 29749 cells in MS blood and 15768 cells in MS CSF
Project description:Gastrointestinal (GI) tract involvement is a major determinant for subsequent morbidity and mortality arising during graft versus host disease (GVHD). CD4+ T cells that produce GM-CSF have emerged as central mediators of inflammation in this tissue site as GM-CSF serves as a critical cytokine link between the adaptive and innate arms of the immune system. However, cellular heterogeneity within the CD4+ GM-CSF+ T cell population due to the concurrent production of other inflammatory cytokines has raised questions as to whether these cells have a common ontology or if there exists a unique CD4+ GM-CSF+ subset that differs from other defined T helper (TH) subtypes. Using single cell RNA sequencing analysis, we identified two CD4+ GM-CSF+ T cell populations that arose during GVHD and were distinguishable by the presence or absence of IFN-γ co-expression. CD4+ GM-CSF+ IFN-γ- T cells which emerged preferentially in the colon had a distinct transcriptional profile, employed unique gene regulatory networks, and possessed a non-overlapping TCR repertoire when compared to CD4+ GM-CSF+ IFN-γ+ T cells as well as all other transcriptionally defined CD4+ T cell populations in the colon. Functionally, this CD4+ GM-CSF+ T cell population contributed to pathological damage in the GI tract which was critically dependent upon signaling through the IL-7 receptor but was independent of type 1 interferon signaling. Thus, these studies help to unravel heterogeneity within CD4+ GM-CSF+ T cells that arise during GVHD and define a developmentally distinct colitogenic TH GM-CSF+ subset that mediates immunopathology.
Project description:The human brain is populated by perivascular CD8+ and CD4+ T cells with a tissue-resident memory T (TRM)-cell phenotype. In multiple sclerosis (MS), these cells associate with white matter (WM) and, to a lesser extent, grey matter (GM) lesions. We here investigated the transcriptional and functional profile of brain-resident T cells. Of n=11 subsequent post-mortem brain donors, we isolated CD8+ and CD4+ effector memory and effector memory re-expressing CD45RA T cells from blood and CD8+ and CD4+ CD69+ T cells from corpus callosum WM and cortical GM. Additionally, brain CD69+ T cells were sorted from subcortical WM, corpus callosum WM, and medulla WM/GM of n=3–5 brain donors as well as from paired normal-appearing WM and GM and from WM and GM lesions of n=6 MS brain donors. In all donors, WM and GM T cells were overwhelmingly CD69+CD103+/-. Bulk RNA sequencing of CD8+ and CD4+ CD69+ T cells revealed TRM-cell signatures, as marked by differential expression of, among others, SELL (CD62L), ITGA1 (CD49a), and S1PR1. Notably, gene expression hardly differed between lesional and normal-appearing WM CD8+ and CD4+ CD69+ T cells in MS brains. Genes up-regulated in brain TRM cells were MS4A1 (CD20) and SPP1 (osteopontin, OPN). OPN is also abundantly expressed by microglia and has been shown to inhibit T-cell activity. In line with the increased presence of OPN in active MS lesions, we noticed a reduced production of the inflammatory cytokines IL-2, TNF, and IFNγ by MS lesion-derived CD8+ and CD4+ T cells ex vivo. This study discloses essential characteristics of human brain CD8+ and CD4+ TRM cells in non-MS and MS post-mortem WM and GM, reports OPN as a generic product of brain-resident immune cells, and shows a tight control of the activation state of TRM cells in MS lesions.
Project description:Elevated frequencies of GM-CSF-producing helper T (TH) cells are consistently found in multiple sclerosis (MS) patients and GM-CSF expression is a non-redundant feature of pathogenic TH cells in preclinical models of MS. GM-CSF activates an inflammatory signature in monocytes, and their progeny are the most abundant cellular infiltrate in acute MS lesions. To model deregulated GM-CSF levels, we generated a transgenic mouse line allowing the induction of GM-CSF expression in mature, peripheral TH cells. This antigen-independent GM-CSF release induced severe neurological deficits with almost 100% penetrance, accompanied by the infiltration of inflammatory monocyte-derived myeloid cells into the brain stem and spinal cord. Other organs did not show obvious signs for clinical pathology, despite also being infiltrated by inflammatory myeloid cells. We aim to unravel differences between organs, their responses and also the potential of tissue destruction by infiltrating cells by sequencing inflammatory myeloid cells isolate from the individual organs.
Project description:Interleukin-21 (IL-21) has broad actions on T- and B-cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3. Expression of IL-21 in vivo decreased cDC numbers, and this was prevented by GM-CSF. Moreover, repetitive M-NM-1-galactosylceramide injection of mice induced IL-21 but decreased GM-CSF production by natural killer T (NKT) cells, correlating with decreased cDC numbers. Furthermore, adoptive-transfer of wild-type CD4+ T cells caused more severe colitis with increased DCs and interferon (IFN)-M-NM-3-producing CD4+ T cells in Il21r-/-Rag2-/- mice (which lack T cells and have IL-21-unresponsive DCs) than in Rag2-/- mice. Thus, IL-21 and GM-CSF exhibit cross-regulatory actions on gene regulation and apoptosis, regulating cDC numbers and thereby the magnitude of the immune response. Total 6 samples were examined. Splenic dendritic cells were treated with IL-21 and/or GM-CSF studying STAT3 and STAT5B binding in the genome
Project description:Central nervous system B cells have several potential roles in multiple sclerosis (MS): secretors of proinflammatory cytokines and chemokines, presenters of autoantigens to T cells, producers of pathogenic antibodies, and reservoirs for viruses that trigger demyelination. To interrogate these roles, single-cell RNA sequencing (scRNA-Seq) was performed on paired cerebrospinal fluid (CSF) and blood from subjects with relapsing-remitting MS (RRMS; n = 12), other neurologic diseases (ONDs; n = 1), and healthy controls (HCs; n = 3). Single-cell immunoglobulin sequencing (scIg-Seq) was performed on a subset of these subjects and additional RRMS (n = 4), clinically isolated syndrome (n = 2), and OND (n = 2) subjects. Further, paired CSF and blood B cell subsets (RRMS; n = 7) were isolated using fluorescence activated cell sorting for bulk RNA sequencing (RNA-Seq). Independent analyses across technologies demonstrated that nuclear factor kappa B (NF-?B) and cholesterol biosynthesis pathways were activated, and specific cytokine and chemokine receptors were up-regulated in CSF memory B cells. Further, SMAD/TGF-ß1 signaling was down-regulated in CSF plasmablasts/plasma cells. Clonally expanded, somatically hypermutated IgM+ and IgG1+ CSF B cells were associated with inflammation, blood–brain barrier breakdown, and intrathecal Ig synthesis. While we identified memory B cells and plasmablast/plasma cells with highly similar Ig heavy-chain sequences across MS subjects, similarities were also identified with ONDs and HCs. No viral transcripts, including from Epstein–Barr virus, were detected. Our findings support the hypothesis that in MS, CSF B cells are driven to an inflammatory and clonally expanded memory and plasmablast/plasma cell phenotype.