CLIP monoclonal antibody (CerCLIP.1)

CLIP (class II-associated invariant chain peptide) is an important peptide in the MHC-II antigen processing pathway, formed by the enzymatic cleavage of amino acids 81-104 from the invariant chain. During MHC-II synthesis in the ER and transport to endocytic vesicles, the antigen binding site of MHC-II is obstructed by the presence of the invariant chain. As the MHC-II complex moves through the Golgi, the invariant chain is degraded, leaving the CLIP fragment in the MHC-II peptide binding groove. CLIP is eventually displaced by the loading of antigenic peptides, followed by presentation on the APC cell surface to CD4+ T-cells.