Feb 14: CCR9-expressing T cells play a role in the immunopathology of Sjögren's syndrome
PhD research by Anneline Hinrichs at UMC Utrecht shows that in patients with primary Sjögren's syndrome (pSS), various types of T cells that express a surface protein called CCR9 are elevated as compared to healthy controls. These findings add to a growing burden of evidence that CCR9-expressing T cells are involved in the immunopathology of pSS.
Primary Sjögren’s Syndrome (pSS) is a chronic autoimmune disease in which most patients have complaints of dryness of eyes and mouth, fatigue, and pain in muscles and joints. The dryness arises from inflammation of the glands inhibiting production of tear fluid and saliva. This inflammation is associated with autoimmunity, leading to damage and functional impairment of the tear- and saliva-producing cells.
Research described in the thesis of Anneline Hinrichs (Department of Rheumatology & Clinical Immunology and Center for Translational Immunology, UMC Utrecht) shows that in the blood of patients with pSS various types of CCR9-expressing T cells are elevated as compared to healthy controls. In addition to increased numbers of CCR9-expressing T cells in pSS patients, these cells also display a more aggressive pro-inflammatory potential in patients. In line with their B cell-stimulating capacities, CCR9-expressing T cell subsets are indicated to play a role in pSS immunopathology by stimulating B cell hyperactivity and T cell-driven responses in the salivary glands of pSS patients.
Apart from the T cell research in pSS, in this thesis Anneline Hinrichs and colleagues also performed a pilot study to investigate various systemic autoimmune diseases such as pSS, systemic sclerosis (SSc) and systemic lupus erythematosus (SLE), using a novel minimal-invasive technique. In this study, sebum was sampled from the skin using special tape, after which the sebum was used to measure metabolites. Metabolite ions found in the different patient groups were compared to each other as well as to those from healthy controls. The biggest difference in metabolite ions was found between healthy controls and SSc patients, a disease associated with skin involvement. Furthermore, between patients with SSc and pSS the overlap in aberrant metabolite ions was high. This is the first study showing the potential of a new, non-invasive strategy for identifying biomarkers in various autoimmune diseases and will be studied further.
PhD defense
Anneline Hinrichs (1991, Oegstgeest) defended her PhD thesis on February 14, 2023 at Utrecht University. The title of her thesis is “The role of CCR9-expressing T cell subsets in the immunopathology of primary Sjögren's syndrome.” Supervisor was prof. dr. Floris Lafeber (Department of Rheumatology & Clinical Immunology, UMC Utrecht). Co-supervisors were dr. Joel van Roon and dr. Aike Kruize (Center for Translational Immunology and Department of Rheumatology & Clinical Immunology, UMC Utrecht). In September 2022, Anneline started her training in rheumatology at the Amsterdam University Medical Center, the Netherlands. As part of this training, she works as a resident in internal medicine at Spaarne Hospital in Haarlem/Hoofddorp. The PhD research project of Anneline Hinrichs was financially supported by ReumaNederland.