IL-33/ST2

Class

Anti-ST2 (IL-33 receptor) monoclonal antibody

IL-33 is a member of the interleukin-1 cytokine family that functions as an 'alarmin' — a signal released from stressed, damaged, or necrotic epithelial and endothelial cells lining the airways, skin, and gut. Once released, IL-33 binds its receptor, ST2 (also called IL1RL1), which is expressed on innate lymphoid cells, mast cells, basophils, eosinophils, and certain T helper cells. This interaction triggers intracellular signaling that promotes the production of type 2 cytokines, a cluster of inflammatory mediators long implicated in allergic and eosinophilic disease. Because IL-33 acts near the top of this signaling cascade, interrupting it before downstream cytokines are made offers a way to blunt an entire inflammatory program rather than a single mediator. Antibodies directed against ST2 work by occupying the receptor so that IL-33 cannot engage it, effectively silencing the alarm signal at its point of reception. This mechanism is of broad interest in diseases characterized by epithelial barrier disruption and type 2 immune activation, including asthma, chronic obstructive pulmonary disease, and atopic dermatitis, where recurring tissue damage perpetuates a self-sustaining cycle of alarmin release and inflammatory amplification.