RANTES/CCL5 Protein, Human

RANTES/CCL5 (Regulated upon Activation, Normal T-cell Expressed and Secreted) is a member of the CC chemokine family first identified by subtractive hybridization as a T-cell-specific transcript. It is an 8 kDa protein secreted by platelets, T cells, endothelial cells, fibroblasts, epithelial cells, and many tumor types. RANTES exerts its biological effects through binding to the G-protein-coupled receptors CCR1, CCR3, CCR4 and CCR5, triggering intracellular calcium flux and directional migration of monocytes, memory T cells, eosinophils, basophils and natural killer cells. In addition to its chemotactic activity, RANTES can oligomerise on glycosaminoglycans of the endothelial surface, forming immobilised gradients that guide leukocyte extravasation. Proteolytic removal of its two N-terminal amino acids by CD26/DPPIV converts RANTES into a potent receptor antagonist that blocks HIV-1 entry through CCR5.