Purified anti-mouse CD223 (LAG-3)

CD223, also known as LAG-3, is 70 kD type I transmembrane glycoprotein within the Ig superfamily. It is the gene product of lymphocyte activation gene-3 (Lag3) with structural similarity to CD4. CD223 is expressed on activated T cells and NK cells, as well as T regulatory cells. CD223, like CD4, binds MHC class II molecules, but with higher affinity than CD4. In association with the CD3 complex, CD223 has been shown as a negative regulatory molecule to inhibit TCR-mediated signaling and regulate homeostatic T cell expansion. In contrast to inhibition, CD223 has an activation function to promote immune responses by inducing MHC class II signaling in antigen presenting cells.