Description: Thymic Stromal Lymphopoietin (TSLP) is a member of the B cell-stimulating factor family. Originally identified from the conditioned medium of a mouse thymic stromal cell line that promoted B-cell development, TSLP is expressed in thymus, spleen, kidney, lung, and bone marrow. TSLP activity overlaps with that of IL-7, playing a key role in the development of B cells, as well as stimulating the growth of thymocytes and T cells. TSLP stimulates monocytes to produce T cell-attracting chemokines such as TARC (CCL17) and MDC (CCL22). TSLP also activates dendritic cell-primed CD4 T cells to produce Th2 cytokines, including IL-4, IL-5, IL-13, and TNF alpha. This hematopoietic cytokine binds to a heterodimeric receptor complex consisting of the IL-7R alpha chain (CD127) and the TSLP-specific chain (TSLPR). Binding induces activation of STAT3 and STAT5 via phosphorylation. Mouse TSLP shares approximately 43% amino acid sequence identity with human TSLP. Recombinant mouse TSLP is a 15.0 kDa protein consisting of 121 amino acid residues.