T-helper 2 cytokine axis (Th2 axis)

The T-helper 2 (Th2) cytokine axis is a fundamental signaling network of the adaptive immune system, primarily mediated by the interleukins IL-4, IL-5, and IL-13 (Gandhi et al., 2016, Nature Reviews Drug Discovery). These cytokines are secreted by Th2-polarized CD4+ T cells, group 2 innate lymphoid cells (ILC2s), and other granulocytes to coordinate the "Type 2" immune response, which is physiologically essential for defense against helminth parasites (Wenzel, 2012, Nature Medicine). However, overactivation of this axis is the hallmark of many allergic and eosinophilic disorders; IL-4 and IL-13 drive B-cell class switching to IgE and promote airway hyperreactivity, while IL-5 is the primary driver of eosinophil maturation and survival (Corren, 2019, Annals of the American Thoracic Society). Pharmacological intervention in this axis involves monoclonal antibodies that either neutralize the cytokines themselves or block their specific receptors, such as dupilumab (targeting IL-4Rα) and mepolizumab (targeting IL-5) (Pelaia et al., 2022, Frontiers in Pharmacology). These therapies have become the standard of care for patients with "Type 2 high" inflammatory conditions, significantly reducing exacerbation rates and improving clinical outcomes (FDA, 2023).

Other names

Type 2 inflammation pathwayTh2 pathwayIL-4/IL-5/IL-13 signaling axisType 2 cytokine axis

Inhibition of Type 2 cytokines (IL-4, IL-5, IL-13) or their respective receptors using monoclonal antibodies to block downstream JAK/STAT signaling and inflammatory gene expression.