Sensory Nociceptive Nerve Fibers, Key Regulator of Immune Response Type 2 in Atopic Dermatitis

Summary

The skin is innervated by a network of nociceptive sensory neurons (nociceptors) whose primary function is the transmission of pain and pruritus signals to the central nervous system. Their role in atopic dermatitis (AD), characterized by an exacerbated type 2 immune response, is only partially understood. Nevertheless, large amounts of neuropeptides, including substance P (SP), are found in the serum of patients, their level being correlated with the clinical severity of AD. Mast cells (MC) are part of the cells of the immune system residing in the skin. MCs have neuro-receptors of the Mas-related G protein-coupled receptors family (MRGPR) and in particular MRGPRX2 (the receptor for cationic molecules \[including SP\] for MCs) through which they could communicate in a privileged way. with the nociceptors. Preliminary data obtained in mice show that its mouse orthologue "MrgprB2" is absolutely necessary for the development of type 2 immunity and the pathological characteristics of a preclinical "DA-like" model (manuscript in preparation). The investigators therefore hypothesize that the activation of MCs expressing MRGPRX2 by nociceptors producing SP plays a key role in the development of type 2 inflammation in AD in humans.

Conditions

• Atopic Dermatitis

Interventions

OTHER

Clinical examination

This is a classic dermatological clinical examination during a classic consultation

PROCEDURE

Biopsies

2 skin biopsies on a lesion area selected according to the inclusion criteria (2 punchs of 4 mm) for each experimental group. The first half of whole cutaneous biopsies (n = 25) will be studied using biphotonic microscopy. This will be performed on whole biopsies in 3-D according to the protocol developed in the laboratory. The second half of whole skin biopsies (n = 25) will be studied using the technique of single-cell RNA seq. The skin controls skin-free subjects will be obtained from skin reduction surgery (abdominoplasty) to subjects who have agreed to the use of their skin sample.

OTHER

Blood test

A blood test on a tube (2 tubes of 10 mL).An assay of specific IgE and the serum level of IL-4, IL-13 and IL-5 will be carried out by ELISA (Enzyme Linked ImmunoSorbent Assay) from the blood samples.The blood samples will be obtained through the French blood establishment from different donors who have given their consent.

Sponsors & Collaborators

• University Hospital, Toulouse

  lead OTHER

Principal Investigators

• Marie TAUBER · University Hospital, Toulouse

Study Design

Allocation

NON_RANDOMIZED

Purpose

HEALTH_SERVICES_RESEARCH

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-05-07

Primary Completion

2022-02-03

Completion

2022-12-31

Countries

• France

Study Locations