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

Recruiting
Conditions
Type1diabetes
Interventions
Diagnostic Test: MAIT cells analysis
Diagnostic Test: MAIT cytokines production analysis
Procedure: UGI Endoscopy
Diagnostic Test: Lactulose/Mannitol Test
Diagnostic Test: Coxsackie virus B infection status
Registration Number
NCT05054361
Lead Sponsor
Institut National de la Santé Et de la Recherche Médicale, France
Brief 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

Detailed Description

Subjects: Multi study. Subjects will be included in the pediatric diabetes and endocrinology unit in Necker Sick children hospital and in the pediatric unit of ANTONY hospital.

* Recent-onset (RO) n=40: New onset patients will be included shortly after diagnosis.

* At risk (AR) cohort n=70: Routinely screened siblings of T1D patients previously tested positive for HLA DR3 and DR4 will be asked to be a part of the study.

* Control (C) cohort (n=50): Control subjects will be patients consulting at Necker Hospital for endocrine testing

* Control for Endoscopy (CE) n= 20: patients consulting at Necker Hospital or at Antony hospital for UGI endoscopy

Analysis:

MAIT cell 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. 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.

Gut microbiota analysis: 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.

Coxsackie virus B (CVB) infection status: Specific antibodies against coxsackie virus B 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 q-PCR and immunochemistry will be performed on a subset of patients.

Gut integrity: the investigators will assess the permeability of the intestine using the Lactulose-Mannitol test in a sub sample of RO, RD and AR groups (\> 5 years of age, n=20). In brief 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 after ingestion.

Gut mucosa analysis: In a subset of patients (without celiac disease as determined by the dosage of antibodies against transglutaminase), duodenal biopsies will be obtained during an IUG endoscopy . Duodenal biopsy will be performed in RD subjects older than 8 years of age and in CE subjects older than 4 years of age. These 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.

Based on previous study, the sample size should allow statistical differences between AR, RO and C groups. The investigators anticipate to observe blood MAIT cell abnormalities in RO patients and some at risk children after seroconversion but before diabetes onset. This new data will strengthen our predictive model (see preliminary data). Since MAIT cells recognize bacterial ligand we hypothesize that MAIT cells alteration could occur in parallel with microbiota changes and/or CVB infection. The investigators anticipate observing gut mucosa abnormalities in RO children and the severity of these abnormalities may correlate with the level of MAIT cells defect and the presence of CVB infection. The investigators expect to demonstrate that MAIT cells represent a new biomarker of progression toward diabetes as well as a functional immune marker of the aggressiveness of the autoimmune disease. As such this study could determine the accurate therapeutic window for preventive strategies based on MAIT cells manipulation.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
180
Inclusion Criteria

Recent onset group

  • age > 12 months and < 15 years
  • recently diagnosed type 1 diabetes according ISPAD criteria

At risk subjects:

  • age > 12 months and < 15 years
  • siblings of type 1 diabetic patient
  • HLA DR3 and DR4 positive

Control subjects:

  • age > 12 months and < 15 years
  • no HLA associated with high risk type 1 diabetes
  • no antibodies against pancreas antigenes

Control subjects for UGI endoscopy:

  • age > 12 months and < 15 years
  • suspicion of coeliac disease or gastritis
Exclusion Criteria

For all groups:

  • no health care insurance
  • parents or tutors unable to sign the consent
  • personal history of autoimmune disease and/or inflammatory disease except from T1D for RD and CE groups
  • use of corticosteroids during the month before inclusion
  • pregnant subjects
  • medical contraindication of anesthetic topics

For control subjects for UGI endoscopy control and Recent onset-endoscopy group:

  • age below 8 years for Recent onset-endoscopy group
  • age below 4 for UGI endoscopy control group
  • cardiac or respiratory insufficiency, cardiac rhythm disorders, coagulation disease, patients treated with anticoagulant or antiaggregant drug
  • history of allergy to anesthetic drug

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
recent onset patientsMAIT cells analysispatients with recently diagnosed type 1 diabetes
at risk patientsCoxsackie virus B infection statuspatients with a high genetic risk type 1 diabetes
control subjects for endoscopyUGI Endoscopypatients without type 1 diabetes requiring UGI endoscopy for any medical reason
recent onset patientsMAIT cytokines production analysispatients with recently diagnosed type 1 diabetes
recent onset patientsUGI Endoscopypatients with recently diagnosed type 1 diabetes
at risk patientsMAIT cytokines production analysispatients with a high genetic risk type 1 diabetes
at risk patientsLactulose/Mannitol Testpatients with a high genetic risk type 1 diabetes
control subjectsLactulose/Mannitol Testcontrol patients (no risk of type 1 diabetes and no diagnosed type 1 diabetes)
recent onset patientsLactulose/Mannitol Testpatients with recently diagnosed type 1 diabetes
at risk patientsMAIT cells analysispatients with a high genetic risk type 1 diabetes
recent onset patientsCoxsackie virus B infection statuspatients with recently diagnosed type 1 diabetes
control subjectsMAIT cytokines production analysiscontrol patients (no risk of type 1 diabetes and no diagnosed type 1 diabetes)
control subjects for endoscopyMAIT cells analysispatients without type 1 diabetes requiring UGI endoscopy for any medical reason
control subjects for endoscopyMAIT cytokines production analysispatients without type 1 diabetes requiring UGI endoscopy for any medical reason
control subjectsMAIT cells analysiscontrol patients (no risk of type 1 diabetes and no diagnosed type 1 diabetes)
control subjectsCoxsackie virus B infection statuscontrol patients (no risk of type 1 diabetes and no diagnosed type 1 diabetes)
control subjects for endoscopyCoxsackie virus B infection statuspatients without type 1 diabetes requiring UGI endoscopy for any medical reason
Primary Outcome Measures
NameTimeMethod
blood MAIT cells frequencySample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

percentage of MAIT cells in the peripheral blood

Secondary Outcome Measures
NameTimeMethod
MAIT cells membrane markers analysisSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

CD25 positive cells in percentage, CD69 positive cells in percentage, CD44 positive cells in percentage, PD1 positive cells in percentage , KLRG1 positive cells in percentage, TIM3 positive cells in percentage

Cytokines production in the cytoplasm of the MAITSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

Antibodies against IL- 2 , IFN-y, TNF-α, IL-2, IL-10, IL-13, IL-17 and granzyme B expressed in Cells %

Evaluation of gut mucosal integritySample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

qPCR for the expression of key epithelial molecules and cytokines on gut samples

MAIT cell ligands measurementsSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

Percentage of MAIT cells activated in vitro when cultivated in presence of subject stool sample

Presence of CVB in the stoolsSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

CVB specific ARN detection in subjects stools samples by qPCR

Blood immunoglobulins against CVB infection statuSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

Specific antibodies (Ig G) against CVB measurements in patients blood sample

Measurement of intestinal gut mucosal permeabilitySample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

Assessing the permeability of the intestine using the Lactulose-Mannitol test. Concentration of lactulose and manitol in subjects urine samples in mg/dl

16 S sequencing in the Subjects stoolsSample collected the day of enrollment (Control group and at risk patients) or up to 7 days after diagnosis and day of enrollment (recent onset group)

The 16S rRNA gene sequencing will be used for the classification and identification of microbes species in subjects stools. Each species will be identified and quantified as a percentage of the total number of identified species in the stools.

Trial Locations

Locations (2)

Hopital privé d'Antony

🇫🇷

Antony, France

Hopital Necker enfants malades

🇫🇷

Paris, France

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