IL-33

Class

Anti-IL-33 monoclonal antibody

IL-33 is a cytokine belonging to the interleukin-1 family that functions as an 'alarmin': it is stored inside epithelial and endothelial cells lining barrier tissues such as the lungs, skin, and gut, and is released when those cells are damaged by infection, allergens, or mechanical injury. Once released, IL-33 binds its receptor, ST2, on immune cells including mast cells, group 2 innate lymphoid cells, and T helper cells, triggering a signaling cascade that promotes what is called type 2 inflammation—a pattern of immune activity marked by eosinophil recruitment, mucus production, and airway or tissue remodeling. This pathway is central to diseases such as asthma, chronic obstructive pulmonary disease, and atopic dermatitis, where chronic epithelial damage leads to repeated IL-33 release and sustained inflammation. Monoclonal antibodies directed against IL-33 work by binding the cytokine before it can engage its receptor, aiming to interrupt this signal at its earliest point, upstream of many other inflammatory mediators. Because IL-33 sits near the top of the inflammatory cascade, neutralizing it has the potential to dampen multiple downstream effects simultaneously, offering a rationale distinct from therapies that target a single downstream cytokine.