Exploratory Study of the Efficacy of HuMoSCs (Human Monocyte-derived Suppressor Cells) on Glandular Involvement in Sjögren's Syndrome

Dry syndrome is a key feature of this condition, almost always leading to dryness of the mouth and eyes. It manifests as a decrease in the production of saliva and tears, causing discomfort for patients. This chronic dryness contributes to oral and ocular conditions.

It is caused by lymphocytic infiltration of the exocrine glands, leading to their inflammation and subsequent fibrosis, which results in a decrease in fluid production by these glands.

This chronic inflammation causes fatigue in the patient. Furthermore, in 30 to 60% of cases, Sjögren's syndrome may involve extra-glandular involvement, most commonly affecting the joints, but also involving the lungs, nervous system, and kidneys. Additionally, patients with thisdisease have a higher risk of developing lymphoma compared to unaffected individuals.

The current treatment for Sjögren's syndrome is the same as that for dry eye syndrome; it is primarily symptomatic, involving lifestyle and dietary changes, the use of eye drops or oral lubricants, and medication to stimulate saliva production. To date, there is no medication available to treat Sjögren's syndrome and thus the cause of dry eye syndrome.

In our laboratory (INSERM 1098, UMR Right), we have developed cells that suppress the immune system (immunosuppressive cells) derived from human monocytes cultured ex vivo using a patented process called HuMoSC (Human Monocyte -derived Suppressor Cells). These cells possess strong immunosuppressive capacity, already demonstrated in vitro and in vivo in mouse models.

The aim of this study is to evaluate whether HuMoSCs can reduce the accumulation of immune cells and thereby decrease chronic inflammation and, in the longer term, limit the development of fibrosis (hardening with tissue destruction and scarring) in the salivary glands.

Biopsy of the accessory salivary glands is already part of the diagnostic process for Sjögren's syndrome. During this biopsy, additional accessory salivary glands will be collected and sent to the laboratory for this study. These glands will be cultured in the presence of HuMoSC supernatant, and the impact of this treatment will be analyzed.