LAG-3 (mouse):Fc (mouse), (recombinant)

The lymphocyte activation gene-3 (LAG-3, CD223), a member of the immunoglobulin superfamily (IgSF) related to CD4, binds to the major histocompatibility complex (MHC) class II molecules but with higher affinity than CD4. Several alternative mRNA splice-variants of human LAG-3 have been described, two of them encoding potential secreted forms: LAG-3V1 (i.e. the D1-D2 domains of the protein, 36 kDa) and LAG-3V3 (D1-D3, 52 kDa). The longer form was detected by ELISA in the serum of healthy individuals as well as of tuberculosis patients with a favorable outcome. LAG-3 expression by T cell clones correlated with IFN-γ production, and hence soluble LAG-3 has been suggested as a serological marker of Th1 responses.