Polyclonal Antibody to SIP1 receptor/Edg-1

S1PR1 (Sphingosine-1-phosphate receptor 1) is a G-protein coupled receptor, which binds the bioactive S1P (sphingolipid, sphingosine-1-phosphate) as a high affinity ligand. S1P is present at high levels in blood and lymph, and plays a critical role in the homeostasis of the vascular and immune systems. S1PR1 was originally identified as an abundant transcript in endothelial cells and plays a key role in regulating endothelial cell cytoskeletal structure, migration, capillary-like network formation and vascular maturation. In the immune system, S1PR1 signaling is important in the regulation of lymphocyte migration and trafficking. Inhibition of S1PR1 results in lymphocyte sequestration within lymphoid organs. S1PR1 may also regulate tumor cell functions in some types of B cell lymphoma. Inhibition of S1PR1 expression down regulates signal transducer and activator of transcription 3 activity, leading to inhibition of lymphoma tumor cell growth. S1PR1 signaling in T cells drives Treg accumulation in tumors, limits CD8+ T cell recruitment and activation, and promotes tumor growth.