Interleukin 13

The human IL-13is encoded by the IL13 gene. IL-13 was first cloned in 1993 and is located on chromosome 5q31.1 with a length of 1.4kb. ==Functions==

IL-13 has effects on immune cells that are similar to those of the closely related cytokine IL-4. This can be resulted from an allergic reaction brought about when facing an Ala gene. IL-13 also binds to another receptor known as IL-13Rα2. The IL-13Rα2 subunit binds only to IL-13 and it exists in both membrane-bound and soluble forms in mice. Goblet cells are filled with mucin (MUC). == Evolution ==

IL-13 is closely related to IL-4, and both stimulate Type 2 immunity. Genes of this family have also been found in fish, both in bony fish and cartilaginous fish; because at that evolutionary level they can't be distinguished as IL-4 or IL-13, they have been named IL-4/13. == Clinical significance ==

IL-13 specifically induces physiological changes in parasitized organs that are required to expel the offending organisms or their products. For example, expulsion from the gut of a variety of mouse helminths requires IL-13 secreted by Th2 cells. IL-13 induces several changes in the gut that create an environment hostile to the parasite, including enhanced contractions and glycoprotein hyper-secretion from gut epithelial cells, that ultimately lead to detachment of the organism from the gut wall and their removal. The eggs of the parasite Schistosoma mansoni may lodge in a variety of organs including the gut wall, liver, lung and even central nervous system, inducing the formation of granulomas under the control of IL-13. Here, however, the eventual result is organ damage and often profound or even fatal disease, not resolution of the infection. An emerging concept is that IL-13 may antagonize Th1 responses that are required to resolve intracellular infections. In this immune dysregulated context, marked by the recruitment of aberrantly large numbers of Th2 cells, IL-13 inhibits the ability of host immune cells to destroy intracellular pathogens. IL-13 expression has demonstrated to be increased in bronchoalveolar lavage (BAL) fluid and cells in patients with atopic mild asthma after allergen challenge. Genome-wide association studies have identified multiple polymorphisms of IL-13 and genes encoding the IL-13 receptors as associated with asthma susceptibility, bronchial hyperresponsiveness, and increased IgE levels. murine studies demonstrated that IL-13 was both necessary and sufficient to generate asthma-like Th2 responses in the mouse lung. In type I diabetes, IL-13 antagonized cytotoxic insults to pancreatic β cells enhanced by IL-6. In a mouse model of acetaminophen-induced liver injury eosinophil-driven IL-4/IL-13 mediated hepatoprotective function. In severe alcohol-associated hepatitis low plasma level of IL-13 is a predictor of short-term (90-day) mortality. However, in contrast to its short-term beneficiary effects in acute situations, chronically increased IL-13 contributes to development of fibrosis and cirrhosis. Dupilumab is a monoclonal antibody IL-13 and IL-4 modulator that targets the shared receptor of IL-4 and IL-13, IL4Rα. Since IL-4 and IL-13 have similar biological activities, dupilumab may be an effective form of treatment for asthmatic patients. == See also ==