Endogenous and recombinant type I interferons and disease activity in multiple sclerosis

Area of Science:

• Immunology
• Neuroscience
• Cell Biology

Background:

• The role of endogenous type I interferon (IFN) in multiple sclerosis (MS) is debated, despite IFN-β therapy reducing disease activity.
• Understanding the interplay between endogenous IFN, IFN-β treatment, and immune cell responses in MS is crucial.

Purpose of the Study:

• To investigate the relationship between endogenous type I IFN activity, IFN-β therapy effects, and disease activity in MS patients.
• To analyze immune cell profiles, including CD4+ T cells, monocytes, and dendritic cells, in relation to IFN activity and clinical/MRI outcomes.

Main Methods:

• Flow cytometry was used to study CD4+ T cells, CD4+ T cell subsets, monocytes, and dendritic cells.
• Analysis correlated endogenous type I IFN-like activity and IFN-β therapy effects with clinical and MRI-assessed disease activity.

Main Results:

• Endogenous type I IFN activity correlated with decreased CD49d (VLA-4) on CD4+CD26(high) T cells (Th1 helper cells), associated with reduced MRI disease activity.
• IFN-β therapy also reduced CD49d expression, with higher CD49d(high) on CD4+CD26(high) T cells correlating with increased clinical and MRI disease activity.
• IFN-β treatment increased activated T cells (CD71 and HLA-DR expression), linked to higher clinical disease activity risk, an effect not seen in untreated MS patients with endogenous IFN activity.

Conclusions:

• Both IFN-β treatment and endogenous type I IFN activity similarly affect VLA-4 expression, correlating with disease control.
• However, IFN-β therapy's immune-activating effects may counteract benefits and lead to suboptimal treatment responses.