Patients With Severe Multiple Sclerosis Exhibit Functionally Altered CD8 + Regulatory T Cells

International audienceBackground and Objectives Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the CNS. Studies of immune dysfunction in MS have mostly focused on CD4 + Tregs, but the role of CD8 + Tregs remains largely unexplored. We previously evidenced the suppressive properties of rat and human CD8 + CD45RC low/neg Tregs from healthy individuals, expressing Forkhead box P3 (FOXP3) and acting through interferon-gamma (IFN-γ), transforming growth factor beta (TGFβ), and interleukin-34 (IL-34). secretions to regulate immune responses and control diseases such as transplant rejection. To better understand CD8 + CD45RC low/neg Tregs contribution to MS pathology, we further investigated their phenotype, function, and transcriptome in patients with MS. Methods We enrolled adults with relapsing-remitting MS and age-matched and sex-matched healthy volunteers (HVs). CD8 + T cells were segregated based on low or lack of expression of CD45RC. First, the frequency in CSF and blood, phenotype, transcriptome, and function of CD8 + CD45RC low and neg were investigated according to exacerbation status and secondarily, according to clinical severity based on the MS severity score (MSSS) in patients with nonexacerbating MS. We then induced active MOG 35-55 EAE in C57Bl/6 mice and performed adoptive transfer of fresh and expanded CD8 + CD45RC neg Tregs to assess their ability to mitigate neuroinflammation in vivo. Results Thirty-one untreated patients with relapsing-remitting MS were compared with 40 age-matched and sex-matched HVs. We demonstrated no difference of CSF CD8 + CD45RC low and CD8 + CD45RC neg proportions, but blood CD8 + CD45RC low frequency was lower in patients with MS exacerbation when compared with that in HVs. CD8 + CD45RC neg Tregs but not CD8 + CD45RC low showed higher suppressive capacities in vitro in MS patients with exacerbation than in patients without acute inflammatory attack. In vitro functional assays showed a compromised suppression capacity of CD8 + CD45RC low Tregs in patients with nonexacerbating severe MS, defined by the MSSS. We then characterized murine CD8 + CD45RC neg Tregs and demonstrated the potential of CD45RC neg cells to migrate to the CNS and mitigate experimental autoimmune encephalomyelitis in vivo. Discussion Altogether, these results suggest a defect in the number and function of CD8 + CD45RC low Tregs during MS relapse and an association of CD8 + CD45RC low Tregs dysfunction with MS severity. Thus, CD8 + CD45RC low/neg T cells might bring new insights into the pathophysiology and new therapeutic approaches of MS

Saint-Germain-en-Laye (Yvelines), Fort Saint-Sébastien. Volume 3, Etudes de mobilier, analyses botaniques et géoarchéologiques pour les occupations modernes : rapport de fouille

La fouille a été l'occasion de mettre en place une enquête fondée sur l'interdisciplinarité où données archéologiques, paléoenvironnementales, géoarchéologiques, archivistiques et archéogéographiques ont été mobilisées afin de livrer une analyse multiscalaire des faits sociaux et environnementaux.Les études consacrées au mobilier, aux analyses de sédiments et autres prélèvements sont présentées dans le présent volume.Celui-ci rassemble les études du mobilier céramique attribué à la phase moderne (céramiques de consommation, mais aussi pipes en terre cuite et fusées de pétard d'artillerie) ; du mobilier en verre ; des objets métalliques, monnaies et résidus de productions métalliques ; des restes d'ossements animaux liés à la consommation carnée ; du mobilier en os travaillé. L'importance des restes de poisson dans les comblements des fosses à cuire du site a incité les auteurs à réaliser une campagne de prélèvements ambitieuse (2,5 tonnes), bien que ponctuelle, en vue d'une étude ichtyologique et dont les protocoles ont été largement concertés avec le spécialiste. A contrario, les sédiments ont été testés dans un premier temps à la recherche de graines éventuellement carbonisées ou imbibées, mais la pauvreté des échantillons dans les refus de tamis testés a amené l'équipe de fouille à abandonner le projet initial d'études carpologiques et palynologiques. La nature du sédiment gravelo-sableux et l'absence de conditions adéquates ne favorisaient pas la conservation de ce type de restes.Les analyses paléoenvironnementales et géoarchéologiques sont représentées par l'analyse technique des terres crues issues de l'escarpe du premier fort, complétée d'une analyse micromorphologique. Elles ont permis de mieux caractériser la nature et les modalités de construction du parement maçonné.Ont également été menés des analyses parasitologiques sur le contenu des latrines-tonneaux et une analyse anthracologique des refus de tamis de certaines structures de combustion permettant d'affiner la réflexion sur les essences de bois de chauffage et plus largement sur la gestion des espaces forestiers à l'époque moderne. Enfin, le volume se termine par la présentation d'une méthode de photo interprétation inspirée de pratiques mises en place pour la lecture de sites rupestres et qui permit de mettre en évidence des structures non perçues à l’œil nu lors de la fouille

Neuropathologic, phenotypic and functional analyses of Mucosal Associated Invariant T cells in Multiple Sclerosis

International audienceBackground: The involvement of Mucosal Associated Invariant T (MAIT) cells, which are anti-microbial semi-invariant T cells, remains elusive in Multiple Sclerosis (MS).Objective: Deciphering the potential involvement of MAIT cells in the MS inflammatory process. Methods: By flow cytometry, blood MAIT cells from similar cohorts of MS patients and healthy volunteers (HV) were compared for frequency, phenotype, activation potential after in vitro TCR engagement by bacterial ligands and transmigration abilities through an in vitro model of blood-brain barrier. MS CNS samples were also studied by immunofluorescent staining and quantitative PCR.Results and conclusion: Blood MAIT cells from relapsing-remitting MS patients and HV presented similar frequency , ex vivo effector phenotype and activation abilities. MAIT cells represented 0.5% of the total infiltrating T cells on 39 MS CNS lesions. This is low as compared to blood frequency (p b 0.001), but consistent with their low trans-migration rate. Finally, transcriptional over-expression of MR1-which presents cognate antigens to MAIT cells-and of the activating cytokines IL-18 and IL-23 was evidenced in MS lesions, suggesting that the CNS microenvi-ronment is suited to activate the few infiltrating MAIT cells. Taken together, these data place MAIT cells from MS patients as minor components of the inflammatory pathological process

Immune Profiling Reveals the T-Cell Effect of Ocrelizumab in Early Relapsing-Remitting Multiple Sclerosis

Background and objectives: Ocrelizumab (OCR), a humanized anti-CD20 monoclonal antibody, is highly efficient in patients with relapsing-remitting multiple sclerosis (RR-MS). We assessed early cellular immune profiles and their association with disease activity at treatment start and under therapy, which may provide new clues on the mechanisms of action of OCR and on the disease pathophysiology.Methods: A first group of 42 patients with an early RR-MS, never exposed to disease-modifying therapy, was included in 11 centers participating to an ancillary study of the ENSEMBLE trial (NCT03085810) to evaluate the effectiveness and safety of OCR. The phenotypic immune profile was comprehensively assessed by multiparametric spectral flow cytometry at baseline and after 24 and 48 weeks of OCR treatment on cryopreserved peripheral blood mononuclear cells and analyzed in relation to disease clinical activity. A second group of 13 untreated patients with RR-MS was included for comparative analysis of peripheral blood and CSF. The transcriptomic profile was assessed by single-cell qPCRs of 96 genes of immunologic interest.Results: Using an unbiased analysis, we found that OCR as an effect on 4 clusters of CD4+ T cells: one corresponding to naive CD4+ T cells was increased, the other clusters corresponded to effector memory (EM) CD4+CCR6- T cells expressing homing and migration markers, 2 of them also expressing CCR5 and were decreased by the treatment. Of interest, one CD8+ T-cell cluster was decreased by OCR corresponding to EM CCR5-expressing T cells with high expression of the brain homing markers CD49d and CD11a and correlated with the time elapsed since the last relapse. These EM CD8+CCR5+ T cells were enriched in the CSF of patients with RR-MS and corresponded to activated and cytotoxic cells.Discussion: Our study provides novel insights into the mode of action of anti-CD20, pointing toward the role of EM T cells, particularly a subset of CD8 T cells expressing CCR5

An intermediate level of CD161 expression defines a novel activated, inflammatory, and pathogenic subset of CD8+ T cells involved in multiple sclerosis

International audienceSeveral lines of evidence support a key role for CD8+ T cells in central nervous system tissue damage of patients with multiple sclerosis. However, the precise phenotype of the circulating CD8+ T cells that may be recruited from the peripheral blood to invade the CNS remains largely undefined to date. It has been suggested that IL-17 secreting CD8 (Tc17) T cells may be involved, and in humans these cells are characterized by the expression of CD161. We focused our study on a unique and recently described subset of CD8 T cells characterized by an intermediate expression of CD161 as its role in neuroinflammation has not been investigated to date. The frequency, phenotype, and function of CD8+ T cells with an intermediate CD161 expression level were characterized ex-vivo, in vitro, and in situ using RNAseq, RT-PCR, flow cytometry, TCR sequencing, and immunohistofluorescence of cells derived from healthy volunteers (n = 61), MS subjects (n = 90), as well as inflammatory (n = 15) and non-inflammatory controls (n = 6). We report here that CD8+CD161int T cells present characteristics of effector cells, up-regulate cell-adhesion molecules and have an increased ability to cross the blood-brain barrier and to secrete IL-17, IFNγ, GM-CSF, and IL-22. We further demonstrate that these cells are recruited and enriched in the CNS of MS subjects where they produce IL-17. In the peripheral blood, RNAseq, RT-PCR, high-throughput TCR repertoire analyses, and flow cytometry confirmed an increased effector and transmigration pattern of these cells in MS patients, with the presence of supernumerary clones compared to healthy controls. Our data demonstrate that intermediate levels of CD161 expression identifies activated and effector CD8+ T cells with pathogenic properties that are recruited to MS lesions. This suggests that CD161 may represent a biomarker and a valid target for the treatment of neuroinflammation

Teriflunomide and Time to Clinical Multiple Sclerosis in Patients With Radiologically Isolated Syndrome

International audienceImportance Radiologically isolated syndrome (RIS) represents the earliest detectable preclinical phase of multiple sclerosis (MS) punctuated by incidental magnetic resonance imaging (MRI) white matter anomalies within the central nervous system. Objective To determine the time to onset of symptoms consistent with MS. Design, Setting, and Participants From September 2017 to October 2022, this multicenter, double-blind, phase 3, randomized clinical trial investigated the efficacy of teriflunomide in delaying MS in individuals with RIS, with a 3-year follow-up. The setting included referral centers in France, Switzerland, and Turkey. Participants older than 18 years meeting 2009 RIS criteria were randomly assigned (1:1) to oral teriflunomide, 14 mg daily, or placebo up to week 96 or, optionally, to week 144. Interventions Clinical, MRI, and patient-reported outcomes (PROs) were collected at baseline and yearly until week 96, with an optional third year in the allocated arm if no symptoms have occurred. Main outcomes Primary analysis was performed in the intention-to-treat population, and safety was assessed accordingly. Secondary end points included MRI outcomes and PROs. Results Among 124 individuals assessed for eligibility, 35 were excluded for declining to participate, not meeting inclusion criteria, or loss of follow-up. Eighty-nine participants (mean [SD] age, 37.8 [12.1] years; 63 female [70.8%]) were enrolled (placebo, 45 [50.6%]; teriflunomide, 44 [49.4%]). Eighteen participants (placebo, 9 [50.0%]; teriflunomide, 9 [50.0%]) discontinued the study, resulting in a dropout rate of 20% for adverse events (3 [16.7%]), consent withdrawal (4 [22.2%]), loss to follow-up (5 [27.8%]), voluntary withdrawal (4 [22.2%]), pregnancy (1 [5.6%]), and study termination (1 [5.6%]). The time to the first clinical event was significantly extended in the teriflunomide arm compared with placebo, in both the unadjusted (hazard ratio [HR], 0.37; 95% CI, 0.16-0.84; P = .02) and adjusted (HR, 0.28; 95% CI, 0.11-0.71; P = .007) analysis. Secondary imaging end point outcomes including the comparison of the cumulative number of new or newly enlarging T2 lesions (rate ratio [RR], 0.57; 95% CI, 0.27-1.20; P = .14), new gadolinium-enhancing lesions (RR, 0.33; 95% CI, 0.09-1.17; P = .09), and the proportion of participants with new lesions (odds ratio, 0.72; 95% CI, 0.25-2.06; P = .54) were not significant. Conclusion and Relevance Treatment with teriflunomide resulted in an unadjusted risk reduction of 63% and an adjusted risk reduction of 72%, relative to placebo, in preventing a first clinical demyelinating event. These data suggest a benefit to early treatment in the MS disease spectrum. Trial Registration ClinicalTrials.gov Identifier: NCT0312265