ED Sciences de la Vie et de la Santé
CHARACTERIZATION OF HUMAN GUT-DERIVED T FOLLICULAR HELPER CELLS IN HEALTH TO COMPREHEND THEIR RELEVANCE IN AUTOIMMUNITY.
by Iris HASANTARI (Immunologie Conceptuelle, Expérimentale et Translationnelle)
The defense will take place at 14h00 - Salle de conferences, CARF CARF - Université de Bordeaux Campus Carreire, 46, rue Léo Saignat 33076 Bordeaux Cedex
in front of the jury composed of
- Nathalie SCHMITT - Chargée de recherche - Université de Bordeaux - CNRS UMR5164 - Directeur de these
- Luis GRACA - Professeur des universités - Universidade de Lisboa- Instituto de Medicina Molecular João Lobo Antunes - Rapporteur
- Arsène MEKINIAN - Professeur des universités - praticien hospitalier - Department of Internal Medicine, Saint-Antoine Hospital, APHP, Sorbonne University, - Rapporteur
- Carole LE COZ - Chargée de recherche - Institut Toulousain des Maladies Infectieuses et Inflammatoires CHU Purpan - Examinateur
- Helena PAIDASSI - Chargée de recherche - Université Claude Bernard Lyon 1, Bâtiment Rosalind Franklin - Examinateur
- Vanessa DESPLAT - Professeure des universités - Université de Bordeaux- BRIC - Examinateur
Over the past two decades, studies in human and animal models have highlighted the impact of the composition of the gut microbiota on the physiopathology of multiple diseases including autoimmune diseases (AID). The gut microbiota influences health and disease through different pathways including bacterial metabolites, neural signals but also through its impact on the properties of gut immune cells. In mouse models of AID, several studies have shown that the composition of the gut microbiota can alter the properties of gut immune cells which can in turn migrate to different target organs and affect the diseases susceptibility and/or course. These studies raised a broader question about the role of gut-derived immune cells in the pathogenesis of human AID whether or not associated to dysbiosis. T follicular helper (Tfh) cells are a CD4+ T cell subset specialized in helping B cells. They provide B cells with signals required for the generation of antibody-secreting long-lived plasma cells and memory B cells. Due to their specialization in providing help to B cells, Tfh cells play a central role in the pathogenesis of AID. We hypothesize that gut-derived Tfh cells could be relevant in an AID context, yet their characteristics, including under physiological conditions, remain poorly defined. The aim of this PhD is therefore to characterize phenotypically and functionally human gut-derived Tfh cells in a physiological context to better understand their role in the pathogenesis of AIDs.