Allergen-specific T helper type 2 cell (Allergen-specific Th2 cell)

Allergen-specific T helper type 2 (Th2) cells are a specialized subset of CD4+ T lymphocytes that orchestrate the adaptive immune response to environmental allergens. These cells are defined by their expression of the transcription factor GATA3 and the secretion of type 2 cytokines, specifically interleukin-4 (IL-4), IL-5, and IL-13, which promote IgE production, eosinophilia, and airway hyperreactivity (Cousins et al., 2002, JCI). In allergic individuals, these cells escape normal tolerance mechanisms and undergo clonal expansion upon allergen exposure, driving the chronic inflammation seen in conditions like asthma and allergic rhinitis (Wambre et al., 2017, Science Translational Medicine). Therapeutically, allergen-specific Th2 cells are the primary target of allergen immunotherapy (AIT), which seeks to reprogram the immune system toward a state of tolerance by inducing regulatory T cells (Tregs) or shifting the cytokine profile toward a Th1-like response (Akdis & Akdis, 2014, Nature Reviews Drug Discovery). Additionally, modern biologics target the effector molecules produced by these cells, such as IL-5 (mepolizumab) or the shared IL-4/IL-13 receptor (dupilumab), to mitigate the clinical symptoms of Th2-driven diseases (Gandhi et al., 2016, Nature Reviews Drug Discovery). Monitoring these cells via markers like CRTH2 or cytokine production serves as a critical tool for assessing disease severity and treatment efficacy.

Other names

Allergen-reactive Th2 cellType 2 helper T cellTh2 lymphocyteCRTH2+ CD4+ T cell

Therapeutic strategies involve the induction of immune tolerance (anergy or deletion), immune deviation (shifting the response from Th2 to Th1 or regulatory T cells), or the blockade of Th2-derived cytokines (IL-4, IL-5, IL-13) and their receptors to inhibit downstream allergic inflammation.