Description: The eBio15B11.3 monoclonal antibody reacts with human thymic stromal lymphopoietin (TSLP). TSLP is an IL-7-like cytokine derived from epithelial cells, which strongly activates dendritic cells (DC). TSLP can replace the activity of IL-7 in supporting the development of B cells in vitro; it promotes the proliferation and differentiation of committed B220(+) B cell progenitors. TSLP prevents cell death by apoptosis and stimulates growth of the human acute myeloid leukemia cell line MUTZ-3. This effect is neutralized by antibodies directed against IL-7. The TSLP receptor has been shown to be a member of the hematopoietin receptor superfamily. High affinity binding sites require the presence of the alpha chain of the IL-7 receptor (CD127). The receptor complex does not involve the common gamma chain (CD132), a signal-transducing component of various cytokine receptors, including receptors for IL-4, IL-7, IL-9, IL-13, and IL-15. Recently TSLP has been found expressed by keratinocytes of atopic dermatitis; TSLP expression is also associated with Langerhans cell migration and activation in situ. TSLP expressed within thymus and peripheral lymphoid and non-lymphoid tissues regulates DC-mediated central tolerance, peripheral T cell homeostasis, and inflammatory Th2 responses. DCs activated by TSLP can prime naïve CD4 T cells to differentiate into T helper type 2 cells that produce high levels of TNF-α, but no IL-10. This priming for Th2 differentiation is dependent upon TSLP-mediated upregulation of OX40L by DCs.