RecruitingNCT05054361

Crosstalk Between Mucosal-Associated Invariant T (MAIT) Cells and the Gut Microbiota and Mucosa in the Development of Type 1 Diabetes in Children

Crosstalk Between Mucosal-Associated Invariant T Cells and the Gut Microbiota and Mucosa in the Development of Type 1 Diabetes in Children

Sponsor

Institut National de la Santé Et de la Recherche Médicale, France

Enrollment

180 participants

Start Date

Jan 1, 2022

Study Type

OBSERVATIONAL

Conditions

Type1diabetes

Summary

To investigate in a prospective way changes in Mucosal-Associated Invariant T (MAIT) cells frequency, phenotype and function in link with the gut microbiota, gut integrity and the presence of Coxsackie virus B in two cohorts of pediatric patients: patients with a high genetic risk of type 1 diabetes and pediatric patients with recently diagnosed T1D by comparison with control subjects Tasks: 1. To measure blood MAIT cells frequency, phenotype and function in the three cohorts 2. To analyze gut microbiota and the presence of Coxsackie B enterovirus (CVB) and their impact on MAIT cell function 3. To evaluate gut integrity and analyze the gut mucosa 4. To integrate all the data obtained with T1D development and evolution

Eligibility

Min Age: 12 MonthsMax Age: 15 Years

Plain Language Summary

Simplified for easier understanding

This study investigates the relationship between the gut microbiome (the bacteria living in the intestines) and a type of immune cell called MAIT cells in children who have or are at risk for type 1 diabetes. The goal is to understand if gut health plays a role in the development of this autoimmune disease. **You may be eligible if...** - Your child is between 1 and 15 years old - Your child was recently diagnosed with type 1 diabetes, OR is a sibling of a type 1 diabetic child with certain genetic risk markers, OR is a healthy child without those genetic risks (as a control) - You are able and willing to give consent **You may NOT be eligible if...** - You do not have health insurance - Your child has another autoimmune or inflammatory disease (other than type 1 diabetes) - Your child used corticosteroids in the month before the study - You are unable to give informed consent due to language or cognitive barriers Talk to your doctor to see if this trial is right for you.

This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.

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Interventions

DIAGNOSTIC_TESTMAIT cells analysis

For FACS analysis, MAIT cells will be identified as CD3+ CD4- CD161high Vα7.2+ T cells. Surface markers will be analyzed to determine their activation status (CD25, CD69, CD44), their exhaustion (PD1, KLRG1, TIM3), their migration capacity (CCR6), and their proliferation and survival will be analyzed by Ki67 and BCL2 expression.

DIAGNOSTIC_TESTMAIT cytokines production analysis

Cytokine production will be assessed after PMA-ionomycin activation, followed by intracytoplasmic staining with antibodies against IL-2, IFN-γ TNF-α, IL-2, IL-4, IL-10, IL-13, IL-17 and granzyme B. To determine the capacity of MAIT cells to response to TCR stimulation (exhaustion), in vitro stimulation will be performed in the presence of specific bacterial ligands. Activation marker expression will be analyzed by FACS and cytokines released in the supernatant by Cytometry based assay.

DIAGNOSTIC_TESTLactulose/Mannitol Test

After an overnight fast, the patients will drink 50 ml solution of 5 g lactulose and 2 g mannitol. Urine will be collected during before and 5 hours later.

PROCEDUREUGI Endoscopy

Duodenal biopsy collection and analysis. Biopsies will be analyzed by qPCR for the expression of key epithelial molecules such as the fucosyl transferase 2 (fut2), tight junction proteins (occludin, claudin4), antimicrobial peptides (Reg3, LL37) and mucus component (mucin 2). Immune cells function will also be assessed by q-PCR for key cytokines/molecules such as IL-23, IL-17, IL-22, Foxp3, IL-10, TGFb and CVB.

DIAGNOSTIC_TESTCoxsackie virus B infection status

Serology against CVB and CVB specific-qPCR measurement in gut microbiota samples will be performed in all patients of the three cohorts, and analysis of the gut mucosa by qPCR and immunochemistry with anti-CVB VP1 protein mAb will be performed on a subset of patients.

DIAGNOSTIC_TESTCoxsackie virus B infection status

Stool samples are collected and directly kept under anaerobic condition. Within an hour the samples are processed: one fraction is aliquoted and frozen at -80°C and another fraction is used to prepared fecal supernatant for the bioassay of MAIT ligands, aliquoted and frozen. Bioassay to measure the presence of MAIT cell ligands by bioassays using WT3 cell line as well as plate bound MR117. 16S sequencing of all samples and according to the results obtained with the bioassay and 16S, 10 samples will be selected for metagenomic analysis.