title: Opposing roles for IL-13 and IL-13 receptor alpha 2 in health and disease.
abstract: Interleukin (IL)-13 is a key inducer of several type-2 cytokine-dependent pathologies. It regulates inflammation, mucus production, tissue remodeling, and fibrosis. Consequently, it has become an important therapeutic target for a number of debilitating illnesses, including asthma, idiopathic pulmonary fibrosis, ulcerative colitis, as well as several other diseases in which IL-13 is believed to be overproduced. In the murine model of schistosomiasis, IL-13 has emerged as a central mediator of chronic infection-induced liver pathology. Although IL-4, IL-5, IL-10, and IL-13 each regulate distinct aspects of the granulomatous inflammatory response, IL-13 was identified as the primary mediator of liver fibrosis. Thus, elucidating the mechanisms that regulate the production and function of IL-13 has become an intensive area of research. IL-13 signaling is mediated by the type-2 IL-4 receptor, which consists of the IL-4R alpha and IL-13R alpha 1 chains. However, another IL-13-binding chain, IL-13R alpha 2, appears to strongly inhibit the activity of IL-13. Animals deficient in IL-13R alpha 2 fail to downmodulate granuloma formation in the chronic phase of infection. They also develop severe IL-13-dependent fibrosis and portal hypertension and quickly succumb to the infection. Here, we summarize findings from the schistosomiasis model, which illustrate opposing activities for IL-13 and IL-13R alpha 2 in health and disease.
authors.affiliation: Immunopathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Mentink-Kane
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Wynn
mesh_terms: D000818:Animals; D005355:Fibrosis; D006105:Granulomatous Disease, Chronic / Q000209:etiology / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D018793:Interleukin-13 / Q000378:metabolism*; D053661:Interleukin-13 Receptor alpha1 Subunit; D015847:Interleukin-4 / Q000378:metabolism; D008099:Liver / Q000378:metabolism / Q000469:parasitology / Q000473:pathology; D051379:Mice; D016726:Plasma Cell Granuloma, Pulmonary / Q000209:etiology / Q000378:metabolism; D018123:Receptors, Interleukin / Q000378:metabolism*; D053660:Receptors, Interleukin-13; D012552:Schistosomiasis / Q000378:metabolism
chemical_list: C508183:Il13ra1 protein, mouse; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D018123:Receptors, Interleukin; D053660:Receptors, Interleukin-13; D015847:Interleukin-4; D007371:Interferon-gamma