A team of researchers from the University of Tsukuba has discovered an imbalance in the blood of patients with atopic dermatitis. Specifically, they found a higher abundance of mite-specific T cells that promote atopic symptoms, compared to mite-specific regulatory T cells that suppress inflammation. This immune imbalance, favoring pro-inflammatory responses, may hinder the development of immune tolerance to mites, ultimately leading to the manifestation of atopic symptoms.

Tsukuba, Japan—Atopic dermatitis, the most prevalent chronic skin disease affecting 2-5% of adults, poses a perplexing question regarding the role of regulatory T cells (Tregs) in its pathogenesis. Previously, studies have indicated a higher abundance of Tregs in patients with atopic dermatitis compared with that in healthy individuals. Nevertheless, it remains paradoxical that individuals with atopic dermatitis experience symptoms despite having a surplus of Tregs responsible for allergy regulation. To address this contradiction, researchers conducted an analysis focusing on T cells specific to mite antigen—an allergen commonly associated with atopic dermatitis—to shed light on this issue.

The study's findings reaffirmed prior reports, revealing a general tendency for a greater number of Tregs in the atopic dermatitis patient group than that in the healthy control group. However, when examining T cells specific to a particular mite antigen, the researchers discovered a higher proportion of mite-specific effector T cells, which contribute to atopic symptoms, in the atopic dermatitis patient group compared to that in the healthy control group. Moreover, the mite antigen-specific effector T cells in the patient group demonstrated heightened production of inflammatory cytokines IL-4 and IL-13—key players in the development of atopic dermatitis—compared to healthy controls. There were no discernible differences in the immunosuppressive function of mite-specific Tregs between patients and healthy controls.

These findings suggest that the prevalence of proinflammatory mite-specific effector T cells, numerically surpassing suppressive mite-specific Tregs, may contribute to the failure in achieving immune tolerance to mites and the subsequent development of atopic symptoms in patients with atopic dermatitis.

Original Paper

Title of original paper:

Antigen-specific T cell balance reveals why patients with atopic dermatitis fail to achieve immune tolerance

Journal:

Clinical Immunology

DOI:

10.1016/j.clim.2023.109649

Correspondence

Professor TAKADA Hidetosh
Institute of Medicine, University of Tsukuba

Professor OKIYAMA Naoko
Department of Dermatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University

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Institute of Medicine