LAG3/MHC Class II Signaling Pathway

1. LAG3/MHC Class II Signaling Pathway Lymphocyte-activation gene 3, otherwise known as LAG-3, is a protein which in humans is encoded by the LAG3 gene which contains 8 exons. From the sequencing data, the composition of exons and introns and the location of the chromosomes all indicate that the relationship between LGA3 and CD4 is closely related. In human, the gene for LAG-3 lies adjacent to the gene for CD4 on chromosome 12 (12p13) and is approximately 20% identical to the CD4 gene, so it has the same ligand, MHC class II. LAG3, which was found in 1990 and was designated CD223 (cluster of differentiation 223) after the Seventh Human Leucocyte Differentiation Antigen Workshop in 2000, is a cell surface molecule with diverse biologic effects on T cell function. It is an immune checkpoint receptor and as such is the target of various drug development programs by pharmaceutical companies aiming to develop new treatments for cancer and autoimmune disorders. In soluble form, it is also being developed as a cancer drug in its own right. The function of pathway The LAG3 protein, which belongs to immunoglobulin (Ig) superfamily, comprises a 503-amino acid type I transmembrane protein with four extracellular Ig-like domains, designated D1 to D4. According to previous studies, LAG-3 is expressed on activated T cells, natural killer cells, B cells and plasmacytoid dendritic cells. It's principal ligand is MHC class II, to which it binds with higher affinity than CD4. LAG3 was cloned over 20 years ago as a CD4 homologue, but its function in the immune checkpoint was only defined in 2005 when it turned out to have a role in enhancing the function of Treg cells(regulatory cells). The molecular pathways that mediate LAG-3 signaling are still largely unknown, although it is clear that the unique intracellular KIEELE domain is required for its function. https://www.creative-diagnostics.com/lag3-mhc-class-ii-signaling-pathway.htm