SF-20 or IL-25 belongs to the IL-17 family and is also named IL-17E. It is encoded by IL-25 (IL-17E) gene located on chromosome 14 in murine and secreted by several tissues at low levels, for instance, brain, kidney, lung, prostate, testis, spinal cord, adrenal gland, and trachea. This cytokine is initially identified as a product of bone marrow-derived stromal cells and plays an important role in proliferation of lymphoid cells and is considered an interleukin. It rest CD8+ and CD19+ cells and activated CD8+ T cells and has been shown to bind to the surface of cells expressing the receptor TSA-1 (Thymic shared Ag-1). Additionally, it induces the production of other cytokines, including IL-4, IL-5 and IL-13 in multiple tissues, which stimulate the expansion of eosinophils.
Reference
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