Increased numbers of T cells recognizing multiple myelin basic protein epitopes in multiple sclerosis.

Area of Science:

• Neuroimmunology
• Autoimmunity
• T cell immunology

Background:

• Myelin basic protein (MBP)-autoreactive T cells are implicated in experimental allergic encephalomyelitis (EAE).
• The specific T cell response to different MBP epitopes in multiple sclerosis (MS) remains incompletely understood.
• Certain MBP epitopes are known to be immunodominantly recognized.

Purpose of the Study:

• To investigate the quantity and heterogeneity of T cell reactivity to various MBP epitopes in MS patients compared to controls.
• To determine if specific MBP peptides are preferentially recognized in MS.
• To explore the association between HLA-DR genotype and T cell response in MS.

Main Methods:

• Short-term cultures of blood mononuclear cells from MS patients and controls.
• Measurement of T cells secreting interferon-gamma (IFN-γ) upon stimulation with six different MBP peptides.
• Analysis of T cell responses across different MBP peptide sequences and HLA-DR genotypes.

Main Results:

• MS patients demonstrated significantly higher numbers of MBP peptide-reactive T cells compared to controls (10.4–22.5 per 10^5 cells).
• No single MBP peptide was preferentially recognized among the tested epitopes (1-20, 63-88, 89-101, 96-118, 110-128, 148-165).
• No preferential T cell response was observed when MS patients were stratified by HLA-DR genotype.

Conclusions:

• A quantitative increase in a broad repertoire of myelin-autoreactive T cells capable of secreting IFN-γ is likely important in MS pathogenesis.
• The T cell response in MS is directed against multiple MBP epitopes rather than a single dominant one.
• These findings highlight the role of a diverse autoimmune T cell response in the development of MS.