Th2-mediated effector pathway in allergic inflammation (Th2 pathway)

The Th2-mediated effector pathway is a complex immunological cascade primarily responsible for driving allergic inflammation and host defense against helminth infections. It is initiated by the differentiation of naive CD4+ T cells into Th2 cells, which secrete a signature profile of cytokines including Interleukin-4 (IL-4), IL-5, and IL-13 (Corren, 2013; PubMed: 24054361). These mediators promote B-cell class switching to IgE, stimulate eosinophil recruitment and maturation, and induce goblet cell hyperplasia and airway hyperresponsiveness (Fahy, 2015; PubMed: 25554604). In clinical practice, this pathway is a major therapeutic focus for "Type 2-high" inflammatory diseases such as asthma, atopic dermatitis, and chronic rhinosinusitis. Modern biologics target specific nodes within this pathway, such as the IL-4 receptor alpha subunit (Dupilumab) or circulating IL-5 (Mepolizumab), to effectively reduce the inflammatory burden in patients (Gandhi et al., 2016; PubMed: 27748731). While highly effective, targeting this pathway requires careful patient selection using biomarkers like eosinophil counts and FeNO to ensure the underlying pathology is indeed Th2-driven.

Other names

Type 2 inflammationTh2 immune responseAllergic inflammatory cascadeT-helper 2 pathway

Therapeutic agents modulate this pathway by antagonizing specific cytokines (IL-4, IL-5, IL-13) or their receptors (IL-4Rα, IL-5Rα), or by binding to free IgE, thereby inhibiting downstream signaling, reducing eosinophil survival, and preventing mast cell degranulation (Gandhi et al., 2016; PubMed: 27748731).