Publications by authors named "Helene Dumortier"

Introduction: The therapeutic interest of targeting B-cell activating factor (BAFF) in Sjögren's disease (SjD) can be suspected from the results of two phase II clinical trials but has not been evaluated in an animal model of the disease. We aimed to evaluate the therapeutic efficacy of this strategy on dryness and salivary gland (SG) infiltrates in the NOD mouse model of SjD.

Material And Methods: Female NOD mice between ages 10 and 18 weeks were treated with a BAFF-blocking monoclonal antibody, Sandy-2 or an isotype control.

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Objective: Innate lymphoid cells (ILCs) are a cell population implicated in the pathogenesis of various chronic inflammatory diseases, but little is known about their role in primary Sjögren's syndrome (pSS). The aim of this study was to assess the frequency of ILC subsets in peripheral blood (PB) and their quantity and location in minor salivary glands (MSGs) in pSS.

Methods: The frequency of ILC subsets was analysed in the PB of patients with pSS and healthy controls (HCs) by flow cytometry.

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Background: Primary mitral regurgitation (MR) is a heterogeneous clinical disease requiring integration of echocardiographic parameters using guideline-driven recommendations to identify severe disease.

Objectives: The purpose of this preliminary study was to explore novel data-driven approaches to delineate phenotypes of MR severity that benefit from surgery.

Methods: The authors used unsupervised and supervised machine learning and explainable artificial intelligence (AI) to integrate 24 echocardiographic parameters in 400 primary MR subjects from France (n = 243; development cohort) and Canada (n = 157; validation cohort) followed up during a median time of 3.

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Background: Among heart failure (HF) patients undergoing cardiac resynchronization therapy (CRT), those with unfavorable electrical characteristics (UEC) are less frequently CRT responders.

Objectives: In this study, the authors sought to evaluate the relationship between preprocedural echocardiographic parameters of electromechanical dyssynchrony (EMD) and outcome following CRT.

Methods: Among 551 patients receiving CRT, 121 with UEC, defined as atypical left bundle branch, presence of right bundle branch block, or unspecified intraventricular conduction disturbance, were enrolled.

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Objectives: To date, no immunomodulatory drug has demonstrated its efficacy in primary SS (pSS). We sought to analyse potential commonalities between pSS transcriptomic signatures and signatures of various drugs or specific knock-in or knock-down genes.

Methods: Gene expression from peripheral blood samples of patients with pSS was compared with that of healthy controls in two cohorts and three public databases.

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Background: The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains a matter of debate. Myocardial contraction fraction (MCF) - the ratio of the left ventricular (LV) stroke volume to that of the myocardial volume - is a volumetric measure of LV myocardial shortening independent of size or geometry.

Aim: To assess the relationship between MCF and outcome in patients with significant chronic primary MR due to prolapse managed in contemporary practice.

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Vitamin D (VD) deficiency is a highly prevalent worldwide phenomenon and is extensively discussed as a risk factor for the development of systemic lupus erythematosus (SLE) and other immune-mediated diseases. In addition, it is now appreciated that VD possesses multiple immunomodulatory effects. This study aims to explore the impact of dietary VD intake on lupus manifestation and pathology in lupus-prone NZB/W F1 mice and identify the underlying immunological mechanisms modulated by VD.

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The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. We aimed at evaluating the relation between left ventricular ejection time (LVET) and outcome in patients with moderate or severe chronic primary MR because of prolapse. Clinical, Doppler echocardiographic, and outcome data prospectively collected from 302 patients (median age 61 [54 to 74] years, 34% women) with moderate or severe primary MR were analyzed.

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Objective: Primary Sjögren's syndrome (SS) is the second most frequent systemic autoimmune disease, affecting 0.1% of the general population. To characterize the molecular and clinical variabilities among patients with primary SS, we integrated transcriptomic, proteomic, cellular, and genetic data with clinical phenotypes in a cohort of 351 patients with primary SS.

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Background: Discrepancies have been observed between transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) severity grading in primary mitral regurgitation (MR).

Objectives: We sought to compare mitral regurgitant volume (RVol) determined by the TTE proximal flow convergence (proximal isovelocity surface area [PISA]) method and by volumetric methods (TTE and CMR) and to study the relationship between left ventricle (LV) size and RVol obtained by either the PISA or volumetric methods.

Methods: Two centers prospectively recruited 188 patients with at least moderate to severe primary MR due to prolapse in sinus rhythm who underwent TTE and CMR examinations.

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Background: Optimal timing for intervention remains uncertain in asymptomatic patients with primary mitral regurgitation (MR). We aimed to assess the prognostic value of a new cardiac damage staging classification in patients with asymptomatic moderate or severe primary MR.

Methods: Clinical, Doppler-echocardiographic, and outcome data prospectively collected in 338 asymptomatic patients (64 ± 15 years, 68% men) with at least moderate primary MR were retrospectively analyzed.

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B and T lymphocyte attenuator (BTLA) is a co-inhibitory receptor that is expressed by lymphoid cells and regulates the immune response. Consistent with an inhibitory role for BTLA, the disease is exacerbated in BTLA-deficient lupus mice. We recently demonstrated that the BTLA pathway is altered in CD4 T cells from lupus patients.

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Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a loss of tolerance toward self-nucleic acids, autoantibody production, interferon expression and signaling, and a defect in the regulatory T (T) cell compartment. In this work, we identified that platelets from patients with active SLE preferentially interacted with T cells via the P-selectin/P-selectin glycoprotein ligand-1 (PSGL-1) axis. Selectin interaction with PSGL-1 blocked the regulatory and suppressive properties of T cells and particularly follicular T cells by triggering Syk phosphorylation and an increase in intracytosolic calcium.

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Immune checkpoint therapy, where CD8 tumor infiltrating T lymphocytes (TIL) are reactivated, is a promising anti-cancer treatment approach, yet with low response rates. The extracellular matrix, in particular tenascin-C, may generate barriers for TIL. To investigate this possibility, we used a MMTV-NeuNT and syngeneic mammary gland grafting model derived thereof with engineered tenascin-C levels and observed accumulation of CD8 TIL in tenascin-C-rich stroma.

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Inherent immune suppression represents a major challenge in the treatment of human cancer. The extracellular matrix molecule tenascin-C promotes cancer by multiple mechanisms, yet the roles of tenascin-C in tumor immunity are incompletely understood. Using a 4NQO-induced oral squamous cell carcinoma (OSCC) model with abundant and absent tenascin-C, we demonstrated that tenascin-C enforced an immune-suppressive lymphoid stroma via CCL21/CCR7 signaling, leading to increased metastatic tumors.

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Graphene-related materials (GRMs) are widely used in various applications due to their unique properties. A growing number of reports describe the impact of different carbon nanomaterials, including graphene oxide (GO), reduced GO (rGO), and carbon nanotubes (CNT), on immune cells, but there is still a very limited number of studies on graphene. In this work, we investigated the biological responses of few layer graphene (FLG) on mouse macrophages (bone marrow derived macrophages, BMDMs), which are part of the first line of defense in innate immunity.

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Carbon-based nanomaterials represent a new tool in future medical applications. Thus, focusing on the evaluation of the degree of their safety has been growing in the last years. In this study we were particularly interested in understanding the impact of few layer graphene (FLG) on primary murine lymphocytes.

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Coinhibitory receptors play an important role in the prevention of autoimmune diseases, such as systemic lupus erythematosus (SLE), by limiting T cell activation. B and T lymphocyte attenuator (BTLA) is an inhibitory receptor, similar to cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD1), that negatively regulates the immune response. The role of BTLA in the pathogenesis of autoimmune diseases in humans and, more specifically, in SLE is largely unknown.

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The pathogenesis of autoimmune diseases has not been completely elucidated yet, and only a few specific treatments have been developed so far. In autoimmune diseases mediated by pathogenic autoantibodies, such as systemic lupus erythematosus, the specific detection and analysis of autoreactive B cells is crucial for a better understanding of the physiopathology. Biological characterization of these cells may help to define new therapeutic targets.

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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell hyperactivity leading to the production of autoantibodies, some of which having a deleterious effect. Reducing autoantibody production thus represents a way of controlling lupus pathogenesis, and a better understanding of the molecular and cellular factors involved in the differentiation of B cells into plasma cells could allow identifying new therapeutic targets. Follicular helper T cells (TFH) represent a distinct subset of CD4(+) T cells specialized in providing help to B cells.

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Increased activity of T follicular helper (Tfh) cells plays a major pathogenic role in systemic lupus erythematosus (SLE). However, the mechanisms that cause aberrant Tfh cell responses in SLE remain elusive. Here we showed the OX40 ligand (OX40L)-OX40 axis contributes to the aberrant Tfh response in SLE.

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Graphene oxide (GO) is attracting an ever-growing interest in different fields and applications. Not much is known about the possible impact of GO sheet lateral dimensions on their effects in vitro, especially on human primary cells. In an attempt to address this issue, we present a study to evaluate, how highly soluble 2-dimensional GO constituted of large or small flakes affects human monocyte derived macrophages (hMDM).

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Follicular helper T cells (TFH) represent a distinct subset of CD4(+) T cells specialized in providing help to B lymphocytes, which may play a central role in autoimmune diseases having a major B cell component such as systemic lupus erythematosus. Recently, TFH subsets that share common phenotypic and functional characteristics with TFH cells from germinal centers, have been described in the peripheral blood from healthy individuals. The aim of this study was to analyze the distribution of such populations in lupus patients.

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The role of our immune system is to bring efficient protection against invasion by foreign elements, not only pathogens but also any material it may be in contact with. Nanoparticles may enter the body and encounter the immune system either intentionally (e.g.

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