S-antigen specific T helper type 1 response is present in Behcet's disease

Area of Science:

• Immunology
• Autoimmune Diseases
• Ophthalmology

Background:

• Behcet's disease (BD) is a multisystem inflammatory disorder of unknown etiology.
• S-antigen (S-Ag) has been implicated in the pathogenesis of uveitis, a common ocular manifestation of BD.

Purpose of the Study:

• To determine the frequency of S-antigen specific T cells in patients with BD.
• To characterize the phenotype and function of these S-Ag specific T cells.

Main Methods:

• Peripheral blood was collected from active BD patients, inactive BD patients, and healthy controls.
• Interferon-gamma (IFN-γ) enzyme-linked immunospot assay (ELISPOT) was used to detect T cell responses to S-Ag peptides.
• Flow cytometry (CD69, CD45RO) and cytokine analysis were performed to characterize T cell phenotype and function.

Main Results:

• S-Ag specific T cell responses were detected in 56.5% of active BD patients and 25% of inactive BD patients.
• Activated memory CD4+ T cells (CD69+CD45RO+) constituted the majority of S-Ag specific T cells in active BD patients.
• S-Ag stimulation induced IFN-γ and tumor necrosis factor-alpha (TNF-α) production, but not IL-2, IL-4, or IL-17.

Conclusions:

• S-antigen specific T cells, predominantly activated memory CD4+ T cells, are present in active BD patients.
• These T cells may play a role in BD pathogenesis by producing Th1-dominant cytokines.