8 research outputs found

    Human granzyme B regulatory B cells prevent effector CD4+CD25- T cell proliferation through a mechanism dependent from lymphotoxin alpha

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    IntroductionHuman Granzyme B (GZMB) regulatory B cells (Bregs) have suppressive properties on CD4+ effector T cells by a mechanism partially dependent on GZMB. Moreover, these cells may be easily induced in vitro making them interesting for cell therapy.MethodsWe characterized this population of in vitro induced GZMB+Bregs using single cell transcriptomics. To investigate their regulatory properties, Bregs or total B cells were also co-cultured with T cells and scRNAseq was used to identify receptor ligand interactions and to reveal gene expression changes in the T cells.ResultsWe find that Bregs exhibit a unique set of 149 genes differentially expressed and which are implicated in proliferation, apoptosis, metabolism, and altered antigen presentation capacity consistent with their differentiated B cells profile. Notably, Bregs induced a strong inhibition of T cell genes associated to proliferation, activation, inflammation and apoptosis compared to total B cells. We identified and validated 5 receptor/ligand interactions between Bregs and T cells. Functional analysis using specific inhibitors was used to test their suppressive properties and we identified Lymphotoxin alpha (LTA) as a new and potent Breg ligand implicated in Breg suppressive properties.DiscussionWe report for the first time for a role of LTA in GZMB+Bregs as an enhancer of GZMB expression, and involved in the suppressive properties of GZMB+Bregs in human. The exact mechanism of LTA/GZMB function in this specific subset of Bregs remains to be determined

    Transcriptionnal, Phenotypic and functional transcriptional characterization of GZMB+ B cells in the blood of healthy volunteers : development of immunoassays to measure the impact of JAK pathways in atopic dermatitis

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    Les lymphocytes B rĂ©gulateurs sont une population hautement hĂ©tĂ©rogĂšne qui a montrĂ© son efficacitĂ© Ă  supprimer les mĂ©canismes effecteurs du systĂšme immunitaire. Dans la premiĂšre partie de cette thĂšse nous allons Ă©tudier la population de lymphocytes B rĂ©gulateurs mis en Ă©vidence chez les patients transplantĂ©s rĂ©naux opĂ©rationnellement tolĂ©rants, les lymphocytes B rĂ©gulateurs exprimant le granzyme B en comparant le transcriptome, le phĂ©notype et la fonction de lymphocytes B aprĂšs induction de granzyme B et d’une fonction rĂ©gulatrice Ă  des lymphocytes B non rĂ©gulateurs, n’exprimant pas le granzyme B. Nous avons pu mettre en Ă©vidence le rĂŽle de la lymphotoxine alpha dans la biologie de ces cellules, oĂč l’inhibition de cette cytokine par le Pateclizumab diminue l’expression de granzyme B et rĂ©duit leur fonction suppressive. L’inflammation de type 2 et l’expression de cytokines hautement inflammatoires et pruritiques tels que l’IL-13 et l’IL-33 sont hautement pathogĂ©niques dans la dermatite atopique et les traitements anti-JAK ciblant ces voies cytokiniques de façon non spĂ©cifique ont montrĂ© leur efficacitĂ© chez des patients ne rĂ©pondant pas aux traitements conventionnels. Dans la seconde partie de cette thĂšse, nous Ă©voquerons la caractĂ©risation fonctionnelle et phĂ©notypique des cellules immunitaires circulantes de patients atteints de dermatite modĂ©rĂ©e Ă  sĂ©vĂšre, et le dĂ©veloppement de tests immunologiques pour caractĂ©riser l’impact des inhibiteurs de JAK dans ce contexte pathologique.Regulatory B cells are a highly heterogeneous population that has been shown to suppress immune effector functions. In the first part of this thesis, we will study the population of regulatory B lymphocytes found in operationally tolerant kidney transplant patients, the regulatory B lymphocytes expressing granzyme B by comparing the transcriptome, phenotype and function of B cells after induction of granzyme B and regulatory function to non-regulatory B cells, not expressing granzyme B. We were able to demonstrate the role of lymphotoxin alpha in the biology of these cells, where inhibition of this cytokine by Pateclizumab decreases granzyme B expression and reduces their suppressive function. Type 2 inflammation and the expression of highly inflammatory and pruritic cytokines such as IL-13 and IL-33 are highly pathogenic in atopic dermatitis and anti-JAK therapies targeting these cytokine pathways in a non-specific manner have shown efficacy in patients not responding to conventional treatments. In the second part of this thesis, we will discuss the functional and phenotypic characterization of circulating immune cells from patients with moderate to severe dermatitis, and the development of immunological assays to characterize the impact of JAK inhibitors in this pathological context

    CaractĂ©risation transcriptionnelle phĂ©notypique et fonctionnelle des lymphocytes B GZMB+ dans le sang des volontaires sains : dĂ©veloppement de tests immunologiques pour mesurer l’impact des voies JAK dans la dermatite atopique

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    Regulatory B cells are a highly heterogeneous population that has been shown to suppress immune effector functions. In the first part of this thesis, we will study the population of regulatory B lymphocytes found in operationally tolerant kidney transplant patients, the regulatory B lymphocytes expressing granzyme B by comparing the transcriptome, phenotype and function of B cells after induction of granzyme B and regulatory function to non-regulatory B cells, not expressing granzyme B. We were able to demonstrate the role of lymphotoxin alpha in the biology of these cells, where inhibition of this cytokine by Pateclizumab decreases granzyme B expression and reduces their suppressive function. Type 2 inflammation and the expression of highly inflammatory and pruritic cytokines such as IL-13 and IL-33 are highly pathogenic in atopic dermatitis and anti-JAK therapies targeting these cytokine pathways in a non-specific manner have shown efficacy in patients not responding to conventional treatments. In the second part of this thesis, we will discuss the functional and phenotypic characterization of circulating immune cells from patients with moderate to severe dermatitis, and the development of immunological assays to characterize the impact of JAK inhibitors in this pathological context.Les lymphocytes B rĂ©gulateurs sont une population hautement hĂ©tĂ©rogĂšne qui a montrĂ© son efficacitĂ© Ă  supprimer les mĂ©canismes effecteurs du systĂšme immunitaire. Dans la premiĂšre partie de cette thĂšse nous allons Ă©tudier la population de lymphocytes B rĂ©gulateurs mis en Ă©vidence chez les patients transplantĂ©s rĂ©naux opĂ©rationnellement tolĂ©rants, les lymphocytes B rĂ©gulateurs exprimant le granzyme B en comparant le transcriptome, le phĂ©notype et la fonction de lymphocytes B aprĂšs induction de granzyme B et d’une fonction rĂ©gulatrice Ă  des lymphocytes B non rĂ©gulateurs, n’exprimant pas le granzyme B. Nous avons pu mettre en Ă©vidence le rĂŽle de la lymphotoxine alpha dans la biologie de ces cellules, oĂč l’inhibition de cette cytokine par le Pateclizumab diminue l’expression de granzyme B et rĂ©duit leur fonction suppressive. L’inflammation de type 2 et l’expression de cytokines hautement inflammatoires et pruritiques tels que l’IL-13 et l’IL-33 sont hautement pathogĂ©niques dans la dermatite atopique et les traitements anti-JAK ciblant ces voies cytokiniques de façon non spĂ©cifique ont montrĂ© leur efficacitĂ© chez des patients ne rĂ©pondant pas aux traitements conventionnels. Dans la seconde partie de cette thĂšse, nous Ă©voquerons la caractĂ©risation fonctionnelle et phĂ©notypique des cellules immunitaires circulantes de patients atteints de dermatite modĂ©rĂ©e Ă  sĂ©vĂšre, et le dĂ©veloppement de tests immunologiques pour caractĂ©riser l’impact des inhibiteurs de JAK dans ce contexte pathologique

    CaractĂ©risation transcriptionnelle phĂ©notypique et fonctionnelle des lymphocytes B GZMB+ dans le sang des volontaires sains : dĂ©veloppement de tests immunologiques pour mesurer l’impact des voies JAK dans la dermatite atopique

    No full text
    Regulatory B cells are a highly heterogeneous population that has been shown to suppress immune effector functions. In the first part of this thesis, we will study the population of regulatory B lymphocytes found in operationally tolerant kidney transplant patients, the regulatory B lymphocytes expressing granzyme B by comparing the transcriptome, phenotype and function of B cells after induction of granzyme B and regulatory function to non-regulatory B cells, not expressing granzyme B. We were able to demonstrate the role of lymphotoxin alpha in the biology of these cells, where inhibition of this cytokine by Pateclizumab decreases granzyme B expression and reduces their suppressive function. Type 2 inflammation and the expression of highly inflammatory and pruritic cytokines such as IL-13 and IL-33 are highly pathogenic in atopic dermatitis and anti-JAK therapies targeting these cytokine pathways in a non-specific manner have shown efficacy in patients not responding to conventional treatments. In the second part of this thesis, we will discuss the functional and phenotypic characterization of circulating immune cells from patients with moderate to severe dermatitis, and the development of immunological assays to characterize the impact of JAK inhibitors in this pathological context.Les lymphocytes B rĂ©gulateurs sont une population hautement hĂ©tĂ©rogĂšne qui a montrĂ© son efficacitĂ© Ă  supprimer les mĂ©canismes effecteurs du systĂšme immunitaire. Dans la premiĂšre partie de cette thĂšse nous allons Ă©tudier la population de lymphocytes B rĂ©gulateurs mis en Ă©vidence chez les patients transplantĂ©s rĂ©naux opĂ©rationnellement tolĂ©rants, les lymphocytes B rĂ©gulateurs exprimant le granzyme B en comparant le transcriptome, le phĂ©notype et la fonction de lymphocytes B aprĂšs induction de granzyme B et d’une fonction rĂ©gulatrice Ă  des lymphocytes B non rĂ©gulateurs, n’exprimant pas le granzyme B. Nous avons pu mettre en Ă©vidence le rĂŽle de la lymphotoxine alpha dans la biologie de ces cellules, oĂč l’inhibition de cette cytokine par le Pateclizumab diminue l’expression de granzyme B et rĂ©duit leur fonction suppressive. L’inflammation de type 2 et l’expression de cytokines hautement inflammatoires et pruritiques tels que l’IL-13 et l’IL-33 sont hautement pathogĂ©niques dans la dermatite atopique et les traitements anti-JAK ciblant ces voies cytokiniques de façon non spĂ©cifique ont montrĂ© leur efficacitĂ© chez des patients ne rĂ©pondant pas aux traitements conventionnels. Dans la seconde partie de cette thĂšse, nous Ă©voquerons la caractĂ©risation fonctionnelle et phĂ©notypique des cellules immunitaires circulantes de patients atteints de dermatite modĂ©rĂ©e Ă  sĂ©vĂšre, et le dĂ©veloppement de tests immunologiques pour caractĂ©riser l’impact des inhibiteurs de JAK dans ce contexte pathologique

    Role of JAK inhibitors and immune cells in transplantation

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    International audienceImmunosuppressive challenge after transplantation has dual objectives, namely, to efficiently inhibit immune populations involved in acute, chronic, humoral or cellular transplant rejection while minimizing the effect on immune integrity toward pathogens. The current immunosuppressive strategies show limited efficacy and remain associated with strong side effects, and thus, it is essential to develop new strategies. The use of Janus kinase (JAK) inhibitors is one of the new strategies focusing on cytokine pathways. Specifically, the first-generation JAK inhibitors (JAKis) showed low specificity toward the four known JAK molecules and did not exhibit better effects than calcineurin inhibitors, which constitute the standard treatment posttransplantation. However, because the new generation of JAKis present higher specificity, we are gaining further insights on the response of cells to these inhibitions. This review focuses on the impact of JAKis on different immune cell subsets, focusing on their role in transplantation

    Extracellular Vesicles in Transplantation

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    International audienceExtracellular vesicles (EVs) have been extensively studied in the last two decades. It is now well documented that they can actively participate in the activation or regulation of immune system functions through different mechanisms, the most studied of which include protein-protein interactions and miRNA transfers. The functional diversity of EVsecreting cells makes EVs potential targets for immunotherapies through immune cellderived EV functions. They are also a potential source of biomarkers of graft rejection through donor cells or graft environment-derived EV content modification. This review focuses on preclinical studies that describe the role of EVs from different cell types in immune suppression and graft tolerance and on the search for biomarkers of rejection

    Exosomes as New Biomarkers and Drug Delivery Tools for the Prevention and Treatment of Various Diseases: Current Perspectives

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    International audienceExosomes are nano-sized vesicles secreted by most cells that contain a variety of biological molecules, such as lipids, proteins and nucleic acids. They have been recognized as important mediators for long-distance cell-to-cell communication and are involved in a variety of biological processes. Exosomes have unique advantages, positioning them as highly effective drug delivery tools and providing a distinct means of delivering various therapeutic agents to target cells. In addition, as a new clinical diagnostic biomarker, exosomes play an important role in many aspects of human health and disease, including endocrinology, inflammation, cancer, and cardiovascular disease. In this review, we summarize the development of exosome-based drug delivery tools and the validation of novel biomarkers, and illustrate the role of exosomes as therapeutic targets in the prevention and treatment of various diseases

    Development of extracellular vesicle-based medicinal products: A position paper of the group “Extracellular Vesicle translatiOn to clinicaL perspectiVEs – EVOLVE France”

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    International audienceExtracellular vesicles (EV) are emergent therapeutic effectors that have reached clinical trial investigation. To translate EV-based therapeutic to clinic, the challenge is to demonstrate quality, safety, and efficacy, as required for any medicinal product. EV research translation into medicinal products is an exciting and challenging perspective. Recent papers, provide important guidance on regulatory aspects of pharmaceutical development, defining EVs for therapeutic applications and critical considerations for the development of potency tests. In addition, the ISEV Task Force on Regulatory Affairs and Clinical Use of EV-based Therapeutics as well as the Exosomes Committee from the ISCT are expected to contribute in an active way to the development of EV-based medicinal products by providing update on the scientific progress in EVs field, information to patients and expert resource network for regulatory bodies. The contribution of our work group "Extracellular Vesicle translatiOn to clinicaL perspectiVEs - EVOLVE France", created in 2020, can be positioned in complement to all these important initiatives. Based on complementary scientific, technical, and medical expertise, we provide EV-specific recommendations for manufacturing, quality control, analytics, non-clinical development, and clinical trials, according to current European legislation. We especially focus on early phase clinical trials concerning immediate needs in the field. The main contents of the investigational medicinal product dossier, marketing authorization applications, and critical guideline information are outlined for the transition from research to clinical development and ultimate market authorization
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