Purified anti-human GARP (LRRC32)

Glycoprotein A Repetitions Predominant (GARP), also known as leucine rich repeat containing 32 (LRC32), is a 80 kD type I membrane glycoprotein with 20 leucine rich repeats in the extracellular portion of the protein. GARP was found on the surface of megakaryocytes, platelets, and activated Tregs (CD4+, CD25+, FoxP3+ cells) and serves as a receptor for latent TGF-beta. Recent evidence suggests that GARP may play a role in controlling suppressor function of Tregs. A mutation in GARP has been reported in a large Samaritan kindred with Usher syndrome type 1, an autosomal recessive disease characterized by profound congenital sensorineural deafness, vestibular dysfunction, and progressive visual loss. In addition, it has been found that GARP mRNA is highly amplified in different tumors, which indicates that tumor cells may use GARP to express TGF-beta or to capture TGF-beta from their surroundings, resulting in local suppression of anti-tumor immune responses or the induction of Tregs.