LAG-3 Protein, Cynomolgus (Biotinylated, HEK293, mFc)

LAG-3 Protein serves as an inhibitory receptor for antigen-activated T cells and transmits inhibitory signals after binding to ligands such as FGL1, which is a major contributor to the inhibitory function of LAG3 T cells^[1][2]. Upon T cell receptor (TCR) engagement, LAG-3 Protein binds to CD3-TCR in the immune synapse and directly blocks T cell activation. LAG-3 Protein may cooperate with PDCD1/PD-1, potentially acting as a coreceptor for PD-1 and inhibiting antigen-specific T cell activation^[3]. This protein negatively regulates the proliferation, activation, effector function, and homeostasis of CD8(+) and CD4(+) T cells. Furthermore, LAG-3 Protein plays a key role in immune tolerance and is constitutively expressed on a subset of regulatory T cells (Tregs), contributing to their suppressive function^[4]. LAG-3 Protein acts as a negative regulator of plasmacytoid dendritic cell (pDC) activation and exhibits interaction with MHC class II (MHC-II), although the exact role of MHC-II binding remains unclear. LAG-3 may function as a ligand for MHC class II on antigen-presenting cells (APCs), potentially promoting APC activation/maturation and driving Th1 immune responses.