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[Peripheral blood dendritic cell dysfunction in patients with Sjögren's syndrome]
1Department of Rheumatology, Saitama Medical School.
Insights
Dendritic cell (DC) dysfunction and abnormal cell surface antigens were found in Sjögren's syndrome (SS) patients. These findings suggest a role for antigen-presenting cells in SS immune abnormalities.
Area of Science:
- Immunology
- Cell Biology
Context:
- Sjögren's syndrome (SS) is an autoimmune disease characterized by immune system dysfunction.
- Dendritic cells (DCs) are crucial antigen-presenting cells (APCs) involved in initiating immune responses.
Purpose:
- To investigate dendritic cell (DC) function and antigen presentation in Sjögren's syndrome (SS).
- To clarify immune abnormalities in SS by examining APC function.
Summary:
- Mixed lymphocyte reactions (MLRs), including autologous (AMLR) and allogeneic (alloMLR), were significantly reduced in SS patients, indicating DC dysfunction.
- Cell surface expression of HLA-DR, CD80, and CD83 was analyzed. While HLA-DR-positive cells increased, CD80 and CD83 expression also rose on these cells in SS patients.
Impact:
- These findings suggest that SS patients exhibit both DC dysfunction and abnormalities in cell surface antigen expression.
- This research provides insights into the immunological mechanisms underlying Sjögren's syndrome.
Abstract:
The function of dendritic cell (DC), that has the strongest antigen-presenting ability, was investigated for the purpose of clarifying immune abnormalities in Sjögren's syndrome (SS) from the point of view of antigen-presenting cells. DCs were separated from peripheral blood of SS patients, and mixed lymphocyte reaction (MLR) with DCs was observed to examine the function of DC. Autologous MLR (AMLR), which was induced by mixed culture of DCs with autologous T cells, significantly decreased in SS patients (p < 0.01). Allogeneic MLR (alloMLR), which was induced by mixed culture of DCs with allogeneic T cells, also decreased in SS patients, suggesting the presence of DC dysfunction. Cell surface expression rates of HLA-DR, CD 80, and CD 83, which are a first signal of cell surface antigen presentation, a second signal, and a specific antigen of DC, respectively, were then examined. Among HLA-DR-positive cells, CD 80-positive cells and CD 83-positive cells increased in SS patients, compared with normal subjects (p < 0.0003 and p < 0.00009, respectively). From these results, it was inferred that SS patients have not only DC dysfunction, but abnormalities in cell surface antigens as well.