Type 2 cytokine pathway (Th2 pathway)

The Th2 cytokine pathway, also known as the Type 2 inflammation pathway, is a central driver of allergic and eosinophilic diseases (ThermoFisher, 2025; Frontiers in Immunology, 2019). It is characterized by the production of key interleukins, primarily IL-4, IL-5, and IL-13, by T helper 2 (Th2) cells, innate lymphoid cells (ILC2s), and other immune cells (RapidNovor, 2025; Frontiers in Immunology, 2019). These cytokines orchestrate a cascade of events including B-cell isotype switching to IgE, eosinophil recruitment and activation, and mucus hypersecretion (ThermoFisher, 2025; Frontiers in Immunology, 2021). Dysregulation of this pathway leads to chronic inflammatory conditions such as asthma, atopic dermatitis, and chronic rhinosinusitis (MDPI, 2025; MDPI, 2025). Therapeutic modulation of the Th2 pathway involves monoclonal antibodies that neutralize specific cytokines or block their receptors, as well as small molecules like JAK inhibitors that interfere with downstream signaling (MDPI, 2025; Incite Health, 2026). This approach has revolutionized the treatment of moderate-to-severe Type 2-driven diseases by providing targeted alternatives to broad-spectrum immunosuppressants (NIH/PubMed, 2025; NIH/PubMed, 2025).

Other names

Type 2 inflammation pathwayTh2 axisTh2 cytokine signalingType 2 cytokine pathway

Modulation of the Th2 cytokine pathway is achieved through several mechanisms: (1) neutralization of specific cytokines such as IL-5 or IL-13; (2) blockade of shared receptor subunits, such as IL-4Ra, to simultaneously inhibit multiple cytokines like IL-4 and IL-13; (3) inhibition of upstream epithelial 'alarmins' like TSLP that initiate the Th2 response; and (4) small molecule inhibition of downstream signaling components like Janus kinases (JAKs) to prevent gene transcription associated with type 2 inflammation.