GeneAb™ LAG3

LAG3 (Lymphocyte-activation gene 3) was discovered in 1990 and was previously designated as CD223. LAG3 is a cell surface molecule expressed by activated T cells, natural killer cells, B cells and plasmacytoiddendritic cells. It binds to major histocompatibility complex (MHC) class II molecules and serves as an immune checkpoint receptor. LAG3 negatively regulates cellular proliferation, activation and homeostasisof T cells, and plays a role in Treg suppressive function. LAG3 also helps maintain CD8+ T cells in atolerogenic state and, working with PD-1, helps maintain CD8 exhaustion during chronic viral infection. LAG3 expression was detected in tumour infiltrating lymphocytes. IHC revealed LAG3 expression was distributed on lymphocytes scattered in renal cell carcinoma, melanoma and lymphomas. They were also detected in the tumour stroma as well as in the peritumoral tissue. LAG3 is the target of various drug development programs for cancer and autoimmune disorders. In soluble form, it is also being developed as a cancer drug in its own right.