Anti-Human IL-13 Monoclonal Antibody (Tralokinumab)

Interleukin-13 (IL-13) is a pivotal anti-inflammatory and pro-fibrotic cytokine primarily secreted by type 2 helper T cells (Th2), natural killer T cells (NKT), mast cells, and basophils; although structurally homologous to IL-4 and sharing partial signaling pathways, it possesses distinct biological functions. IL-13 exerts its effects mainly by binding to a heterodimeric receptor complex composed of IL-13Rα1 and IL-4Rα, which activates the downstream JAK1/2-TYK2-STAT6 signaling cascade. This mechanism plays a central role in immune regulation by inducing B cell class switching to produce IgE antibodies, promoting macrophage polarization towards the tissue-repairing M2 phenotype, inhibiting pro-inflammatory cytokine production, and enhancing mucus secretion (e.g., MUC5AC) in epithelial cells. Furthermore, IL-13 is a key mediator driving airway hyperresponsiveness and remodeling in allergic diseases such as asthma and atopic dermatitis, and it serves as a critical effector molecule in tissue fibrosis (e.g., pulmonary and hepatic fibrosis) by directly stimulating fibroblast proliferation and collagen deposition. Consequently, monoclonal antibodies targeting IL-13 or its receptors, such as tralokinumab, have emerged as important therapeutic strategies for treating refractory asthma and atopic disorders.