Involvement of Immune Cells Derived From the Intestine in Sjogren's Syndrome
Involvement of Immune Cells Derived From the Intestine in Sjogren's Syndrome
The study aims at defining the role of immune cells derived from the intestine in the
 pathogenesis of Sjogren's disease. This research might open new therapeutic approaches for
 the treatment of autoimmune diseases.
Autoimmune diseases are characterized by a loss of tolerance of the immune system for
 self-antigens. One of the feature of autoimmune diseases is the infiltration of lymphoid
 cells in the tissues damaged by the disease (i.e. kidney in systemic lupus erythematous or
 brain in multiple sclerosis). However, the origins and properties of the immune cells
 infiltrating these target tissues are largely unknown.

 Studies in mouse models have shown that the composition of the gut microbiota can modify the
 susceptibility to autoimmune diseases. These studies demonstrated that the microbiota
 composition can alter the pathogenic properties of T cells in the gut but also in the target
 tissues. For instance, in the experimental autoimmune encephalomyelitis model, the
 composition of the gut microbiota has been shown to modulate the susceptibility to the
 disease and the properties of the pathogenic CD4 T cells in the gut but also in the central
 nervous system. In human an alteration in the composition of the gut microbiota is observed
 in numerous autoimmune diseases, including Sjogren's syndrome, suggesting that perturbation
 of the gut microbiota might be linked to the pathogenicity of immune cells in the target
 organs. However, the mechanisms by which the microbiota impacts the pathogenicity of immune
 cells in the target organs is unknown. It is proposed that gut immune cells directly exposed
 to the microbiota compounds could migrate to the target organs and participate to the buildup
 of tissue damages. This hypothesis is supported by studies in mouse models showing the
 migration of gut CD4 T cells in the inflamed kidney (glomerulonephritis model) or in the
 systemic lymphoid organs (rheumatoid arthritis model). The preliminary data support this
 hypothesis as the investigators have shown that gut-derived CD4 T cells display pathogenic
 properties in human autoimmune diseases. To determine whether and how the gut-derived immune
 cells are involved in the pathogenesis of autoimmune disease, the investigators propose to
 study the origin and properties of immune cells infiltrated in target tissues in autoimmune
 diseases.

 Sjogren's syndrome is a systemic autoimmune disease in which exocrine gland in particular
 lacrimal and salivary glands are affected. One of the hallmark of the disease is the
 infiltration of lymphoid cells in the exocrine glands of the patients. Indeed, the presence
 of lymphoid infiltrate in the minor labial salivary gland of the patients is one of the most
 important diagnostic tool for Sjogren's syndrome. The investigation of lymphoid infiltrates
 requires to perform a biopsy of the labial salivary gland. The investigators propose here to
 take advantage of this minimally invasive procedure to study the properties of the lymphoid
 cells present in the minor salivary glands of Sjogren's patients.

 The study will recruit 200 patients followed in Bordeaux University Hospital in which a
 salivary gland biopsy is performed for a clinical suspicion of Sjogren's syndrome. Blood and
 a biopsy of the minor salivary gland of the lip will be collected during a scheduled visit to
 study the properties of infiltrated immune cells. Clinical and biological disease activity,
 treatment and outcomes will be studied in correlation with the properties of infiltrated
 immune cells. No extra visit will be needed and the biopsy of the minor salivary gland of the
 lip and the blood samples will be collected at the same times as those collected for clinical
 purposes.
Inclusion Criteria:

 -  Suspicion of Sjogren's syndrome based on 2016 American College of Rheumatology (ACR)
 criteria;

 -  Age ≥ 18 years

 -  Being affiliated to health insurance

 -  Willing to participate

 Exclusion Criteria:

 -  Pregnant or breastfeeding women,

 -  Patient concerned by articles L 1121-5 to L 1121-8 (persons deprived of their liberty
 by a judicial or administrative decision, minors, persons of legal age who are the
 object of a legal protection measure or unable to express their consent)