LRRC32 & TGF-beta 1

GARP (LRRC32) is a transmembrane protein that binds latent-TGF-β1 and tethers it on the Treg surface. and has been proved to promote the activation and secretion of transforming growth factor β (TGF-β). The expression of GARP is highly on the surface activated Tregs and increases the suppressive function of Tregs. Additionally, GARP can bind to latent transforming growth factor β (TGF-β), thus promoting secretion and activation of TGF-β. TGF-β plays a critical rule for homeostasis and function of Tregs. Notably, it has been also observed that fibroblasts and endothelial cell lines that express GARP/latent TGF-β1 complexes do not activate TGF-β1. However, it cannot be excluded that specific stimuli are required to trigger TGF-β1 activation from complexes on the surface of these cell types.