Helper T cell subsets: Development, function and clinical role in hypersensitivity reactions in the modern

Andy Ka Chun Kan1, Wang Tik Tang2, Philip H Li1

  • 1Division of Rheumatology and Clinical Immunology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong Special Administrative Region of China.

Heliyon
|May 10, 2024
PubMed

Helper T cells are traditionally classified into T helper 1 (TH1) and T helper 2 (TH2). The more recent discoveries of T helper 17 (TH17), follicular helper T cells (TFH) and regulatory T cells (Treg) enhanced our understanding on the mechanisms of immune function and hypersensitivity reactions, which shaped the modern perspective on the function and role of these different subsets of helper T cells in hypersensitivity reactions. Each subset of helper T cells has characteristic roles in different types of hypersensitivity reactions, hence giving rise to the respective characteristic clinical manifestations. The roles of helper T cells in allergic contact dermatitis (TH1-mediated), drug rash with eosinophilia and systemic symptoms (DRESS) syndrome (TH2-mediated), and acute generalised exanthematous pustulosis (AGEP) (TH17-mediated) are summarised in this article, demonstrating the correlation between the type of helper T cell involved and the clinical features. TFH plays crucial roles in antibody class-switch recombination; they may be implicated in antibody-mediated hypersensitivity reactions, but further research is warranted to delineate their exact pathogenic roles. The helper T cell subsets and their specific cytokine profiles implicated in different hypersensitivity reactions could be potential treatment targets by biologics, but more clinical trials are warranted to establish their clinical effectiveness.

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