Ii-Key

Ii-Key is a synthetic peptide motif derived from the invariant chain (Ii) of the major histocompatibility complex (MHC) class II protein. It is used as part of hybrid vaccine peptides designed to enhance immune responses by improving antigen presentation. The mechanism of action involves covalently linking the N-terminus of an MHC class II epitope to the C-terminus of the Ii-Key segment via a polymethylene bridge. This modification significantly increases the potency and efficiency with which antigenic peptides are presented by MHC class II molecules, thereby enhancing helper T cell activation and immune response. The approach has been shown to increase in vitro presentation potency up to 200-fold compared to epitope-only peptides and boost in vivo helper T cell responses up to eightfold[8]. These hybrid peptides are being developed primarily as vaccines for cancer immunotherapy and other diseases where enhanced T cell help is beneficial.

Other names

Ii-Key/MHC class II epitope peptideIi protein motif