Nuclear BCL10 in primary Sjögren's syndrome

Area of Science:

• Immunology
• Molecular Biology
• Rheumatology

Background:

• Careful control of antigen receptor signaling and nuclear factor kappa B (NFkappaB) activation is crucial to prevent aberrant immune responses.
• BCL10 protein acts as a critical linker between antigen receptor triggering and NFkappaB activation.
• Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by lymphocytic infiltration of exocrine glands.

Purpose of the Study:

• To investigate the expression patterns of BCL10 and NFkappaB in the minor salivary gland infiltrates of patients with primary Sjögren's syndrome (pSS).
• To determine the potential role of BCL10 and NFkappaB in the pathogenesis of pSS.

Main Methods:

• Minor salivary gland tissues from 17 pSS patients and 4 sicca controls were analyzed using immunohistochemistry and immunofluorescence.
• Expression of BCL10 and NFkappaB-p65 in infiltrating lymphocytes was assessed.
• Ectopic germinal centers (GCs) were identified using CD21 staining.

Main Results:

• Nuclear BCL10-positive cells were frequently observed in lymphocytic infiltrates within minor salivary glands, irrespective of ectopic GCs.
• A subset of these BCL10-positive cells were identified as B cells.
• No constitutive NFkappaB activation was detected, as evidenced by the exclusive cytoplasmic localization of p65 in infiltrating lymphocytes.

Conclusions:

• Nuclear expression of BCL10 in infiltrating lymphocytes is a common finding in minor salivary glands of pSS patients.
• BCL10 nuclear expression may serve as a potential biomarker for autoimmune-induced chronic inflammation in pSS.
• Constitutive NFkappaB activation was not a feature of the observed lymphocytic infiltrates in pSS.