APC Rabbit anti-Human CD223/LAG-3 mAb (A28468)

Lymphocyte Activation Gene 3 (LAG-3, CD223) is an immune checkpoint control protein that negatively regulates T cell function and immune responses. As a CD4-like member of the immunoglobulin superfamily, LAG3 consists of an extracellular Ig-like V domain, three Ig-like C2 domains, a transmembrane domain, and a short cytoplasmic tail. LAG3 is primarily expressed on activated CD4+ T cells, CD8+ T cells, regulatory T cells (Tregs), and NK cells, where it is engaged by MHC class II molecules, its only known ligand. Although initially identified for its ability to modulate Treg activity, LAG3 also exerts inhibitory effects on CD8+ T cells. LAG3 is frequently co-expressed with PD-1 on tumor-infiltrating lymphocytes, where both proteins function independently at the cell surface to promote tumor-mediated immune suppression.