Interleukin 13 (IL13) is up-regulated during parasitic infections and participates in hostμs protective immunity against Schistosoma japonicum. This protein promotes eosinophil activation resulting in elevated specific IgE against adult and larval antigens. During acute infection it promotes egg expulsion through increased intestinal contractility. It acts as a liver protective agent where it promotes the formation of liver granulomas in a CD4+ T cell-mediated manner, which results in liver fibrosis. In airway disorders, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis lung disease, IL13 promotes the formation of airway goblet cells, resulting in excess mucus secretion, which in turn, is regulated by IL13-activated autophagy.
