Retinal S-antigen Th1 cell epitope mapping in patients with Behcet's disease.

Abstract

BACKGROUND:

Retinal S-antigen (S-Ag) is a most characterized autoantigen of autoimmune uveitis. The recognized immunodominant epitope of human S-Ag in patients with uveitis has not been identified. In this study, we selected certain patients with active uveitis to map the Th1 cell epitope spectrum of human S-Ag in Behcet's disease(BD).

METHODS:

Blood samples were taken from eight active BD patients who showed an immune response to 40 mixed overlapping peptides spanning the entire sequence of human S-Ag. Peripheral blood mononuclear cells were isolated and stimulated with single S-Ag peptide at 5 microg/ml or 20 microg/ml. Single-cell immune responses were measured by IFN-gamma ELIspot assay.

RESULTS:

BD patients heterogeneously responded to the S-Ag peptides at two concentrations. In general, the responses to 5 microg/ml peptides were slightly stronger than those to 20 microg/ml peptides, while the maximum SFC frequency to single peptide at the two concentrations was similar. Several peptides including P31, P35 and P40 induced a prominent response, with the frequency of S-Ag specific cells being about 0.007%. Significant reactivity pattern shift was noted in patients with different disease courses.

CONCLUSIONS:

Certain active BD patients have S-Ag specific Th1 cells with a low frequency. The S-Ag epitope specificity between patients is highly heterogeneous, and varies with the uveitis course.

• Authors: Changlin Zhao, Peizeng Yang, Hao He, Xiaomin Lin, Liping Du, Hongyan Zhou, Aize Kijlstra
• Journal: Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie (Graefes Arch Clin Exp Ophthalmol) Vol. 247 Issue 4 Pg. 555-60 (Apr 2009) ISSN: 1435-702X [Electronic] Germany
• PMID: 18958488 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Arrestin
• Autoantigens
• Immunodominant Epitopes
• Peptide Fragments

Topics

• Adult
• Amino Acid Sequence
• Arrestin (immunology)
• Autoantigens (immunology)
• Behcet Syndrome (immunology)
• Enzyme-Linked Immunosorbent Assay
• Epitope Mapping
• Humans
• Immunity, Cellular
• Immunodominant Epitopes (immunology)
• Male
• Molecular Sequence Data
• Peptide Fragments (immunology)
• Th1 Cells (immunology)