Dataset Information

Proinflammatory mucosal-associated invariant CD8+ T cells react to gut flora yeasts and infiltrate multiple sclerosis brain.

ABSTRACT: The composition of the intestinal microbiota plays a critical role in shaping the immune system. Modern lifestyle, the inappropriate use of antibiotics, and exposure to pollution have significantly affected the composition of commensal microorganisms. The intestinal microbiota has been shown to sustain inappropriate autoimmune responses at distant sites in animal models of disease, and may also have a role in immune-mediated central nervous system (CNS) diseases such as multiple sclerosis (MS). We studied the composition of the gut mycobiota in fecal samples from 27 persons with MS (pwMS) and in 18 healthy donors (HD), including 5 pairs of homozygous twins discordant for MS. We found a tendency towards higher fungal abundance and richness in the MS group, and we observed that MS twins showed a higher rate of food-associated strains, such as Saccharomyces cerevisiae. We then found that in pwMS, a distinct population of cells with antibacterial and antifungal activity is expanded during the remitting phase and markedly decreases during clinically and/or radiologically active disease. These cells, named MAIT (mucosal-associated invariant T cells) lymphocytes, were significantly more activated in pwMS compared to HD in response to S. cerevisiae and Candida albicans strains isolated from fecal samples. This activation was also mediated by fungal-induced IL-23 secretion by innate immune cells. Finally, immunofluorescent stainings of MS post-mortem brain tissues from persons with the secondary progressive form of the disease showed that MAIT cells cross the blood-brain barrier (BBB) and produce pro-inflammatory cytokines in the brain. These results were in agreement with the hypothesis that dysbiosis of the gut microbiota might determine the inappropriate response of a subset of pathogenic mucosal T cells and favor the development of systemic inflammatory and autoimmune diseases.

SUBMITTER: Gargano F

PROVIDER: S-EPMC9376942 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Proinflammatory mucosal-associated invariant CD8+ T cells react to gut flora yeasts and infiltrate multiple sclerosis brain.

Gargano Francesca F Guerrera Gisella G Piras Eleonora E Serafini Barbara B Di Paola Monica M Rizzetto Lisa L Buscarinu Maria Chiara MC Annibali Viviana V Vuotto Claudia C De Bardi Marco M D'Orso Silvia S Ruggieri Serena S Gasperini Claudio C Pavarini Lorenzo L Ristori Giovanni G Picozza Mario M Rosicarelli Barbara B Ballerini Clara C Mechelli Rosella R Vitali Francesco F Cavalieri Duccio D Salvetti Marco M Angelini Daniela F DF Borsellino Giovanna G De Filippo Carlotta C Battistini Luca L

Frontiers in immunology 20220728

The composition of the intestinal microbiota plays a critical role in shaping the immune system. Modern lifestyle, the inappropriate use of antibiotics, and exposure to pollution have significantly affected the composition of commensal microorganisms. The intestinal microbiota has been shown to sustain inappropriate autoimmune responses at distant sites in animal models of disease, and may also have a role in immune-mediated central nervous system (CNS) diseases such as multiple sclerosis (MS). ...[more]

PMID: 35979352

Similar Datasets

Project description:ObjectiveSystemic sclerosis is an autoimmune disease characterized by fibrosis of the skin and internal organs including the lung. Mucosal-associated invariant T cells are innate-like T lymphocytes able to produce various cytokines and cytotoxic mediators such as granzyme B. A large body of evidence supports a role of mucosal-associated invariant T cells in autoimmune disease but more recent reports suggest also a potential role in fibrotic conditions. Therefore, we herein addressed the question as whether mucosal-associated invariant T cells may have an altered profile in systemic sclerosis.MethodsMucosal-associated invariant T cell frequency was analyzed by flow cytometry, using fresh peripheral blood from 74 consecutive systemic sclerosis patients who were compared to 44 healthy donors. In addition, in-depth mucosal-associated invariant T cell phenotype and function were analyzed in unselected 29 women with systemic sclerosis who were compared to 23 healthy women donors.ResultsProportion of circulating mucosal-associated invariant T cells was significantly reduced by 68% in systemic sclerosis compared to healthy donors (0.78% in systemic sclerosis vs 2.5%, p < 0.0001). Within systemic sclerosis subsets, mucosal-associated invariant T cells were reduced in patients with interstitial lung disease (systemic sclerosis-interstitial lung disease) (0.56% vs 0.96% in patients without interstitial lung disease, p = 0.04). Moreover, in systemic sclerosis patients, mucosal-associated invariant T cells displayed an activated phenotype indicated by markedly increased CD69+ mucosal-associated invariant T cell frequency (20% mucosal-associated invariant T cell CD69+ compared to 9.4% in healthy donors, p = 0.0014). Interestingly, mucosal-associated invariant T cells from systemic sclerosis-interstitial lung disease patients had a more pronounced altered phenotype compared to systemic sclerosis without interstitial lung disease with a correlation between mucosal-associated invariant T cells expressing CCR6+ and mucosal-associated invariant T cell frequency (r = 0.8, p = 0.006).ConclusionCirculating mucosal-associated invariant T cells were reduced and exhibited an activated phenotype in systemic sclerosis patients. This peripheral mucosal-associated invariant T cell deficiency may be related to enhanced apoptosis and/or homing in inflamed tissue, particularly in systemic sclerosis-interstitial lung disease patients.

Project description:Over the past decade, we have contributed to the chemistry of microbial natural products and synthetic ligands, related to riboflavin and uracils, that modulate immune cells called mucosal associated invariant T cells (MAIT cells). These highly abundant T lymphocytes were only discovered in 2003 and have become recognized for their importance in mammalian immunology. Unlike other T cells, MAIT cells are not activated by peptide or lipid antigens. In collaboration with immunology and structural biology research groups, we discovered that they are instead activated by unstable nitrogen-containing heterocycles synthesized by bacteria. The most potent naturally occurring activating compound (antigen) is 5-(2-oxopropylideneamino)-d-ribitylaminouracil (5-OP-RU). This compound is an imine (Schiff base) formed through condensation between an intermediate in the biosynthesis of riboflavin (vitamin B2) and a metabolic byproduct of mammalian and microbial glycolysis. Although it is very unstable in water due to intramolecular ring closure or hydrolysis, we were able to develop a non-enzymatic synthesis that yields a pure kinetically stable compound in a nonaqueous solvent. This compound has revolutionized the study of MAIT cell immunology due to its potent activation (EC50 = 2 pM) of MAIT cells and its development into immunological reagents for detecting and characterizing MAIT cells in tissues. MAIT cells are now linked to key physiological processes and disease, including antibacterial defense, tissue repair, regulation of graft-vs-host disease, gastritis, inflammatory bowel diseases, and cancer. 5-OP-RU activates MAIT cells and, like a vaccine, has been shown to protect mice from bacterial infections and cancers. Mechanistic studies on the binding of 5-OP-RU to its dual protein targets, the major histocompatibility complex class I related protein (MR1) and the MAIT cell receptor (MAIT TCR), have involved synthetic chemistry, 2D 1H NMR spectroscopy, mass spectrometry, computer modeling and molecular dynamics simulations, biochemical, cellular, and immunological assays, and protein structural biology. These combined studies have revealed structural influences for 5-OP-RU in solution on protein binding and antigen presentation and potency; informed the development of potent (EC50 = 2 nM) and water stable analogues; led to fluorescent analogues for detecting and tracking binding proteins in and on cells; and enabled discovery of drugs and drug-like molecules that bind MR1 and modulate MAIT cell function. MAIT cells offer new opportunities for chemical synthesis to enhance the stability, potency, selectivity, and bioavailability of small molecule ligands for MR1 or MAIT TCR proteins, and to contribute to the understanding of T cell immunity and the development of prospective new immunomodulating medicines.

Project description:A recently identified unconventional T cell population known as mucosal-associated invariant T (MAIT) cells are characterized by the expression of semi-invariant T cell receptor (TCR) with a canonical TRAV1-2/TRAJ33 (Vα7.2/Jα33). These evolutionary conserved, innate-like T cells recognize vitamin B metabolites, derived from some bacteria and fungi. Due to their presence not only in the T cell repertoire of mucosal surfaces but also in peripheral blood and liver, and their significant involvement in a wide range of diseases, in-depth characterization of human MAIT cells is a timely requirement. Studies that examined the transcriptome, immunoproteome, and whole-cell proteome characterized the role of cytotoxic molecules and cytokines in effector functions of MAIT cells and their relationship with some other immune cell subsets. As MAIT cells are classified under the CD3+ T cell compartment and the majority express surface receptor CD8, identifying their proteomic relationship with CD3+ and CD8+ T cells is pivotal. Thus, a high-resolution dataset was generated using the cell populations sorted from peripheral blood mononuclear cells of three healthy volunteers to describe the whole cell proteomes of MAIT, CD3+, and CD8+ T cells. Trypsin-digested peptide samples obtained from the methanol co-precipitation method were analyzed using an Orbitrap FusionTM TribridTM mass spectrometer (Thermo Fisher Scientific, USA) inline coupled to nanoACQUITY ultra-performance liquid chromatography system (Waters, USA) to acquire data-dependent shotgun proteomic data (DDA-MS) for label-free quantification. Analysis of raw DDA-MS data using MaxQuant software and maxLFQ identified and quantified 4,442 protein groups at a 1% false discovery rate. Further analysis identified 3,680 proteins which were detected with a single UniProt accession and a minimum of 2 unique or razor peptides. Thus this proteomic dataset can be used as a reference proteome for future studies on human MAIT cells.

Dataset Information

Proinflammatory mucosal-associated invariant CD8+ T cells react to gut flora yeasts and infiltrate multiple sclerosis brain.

Publications

Proinflammatory mucosal-associated invariant CD8+ T cells react to gut flora yeasts and infiltrate multiple sclerosis brain.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets