Clone REA296 recognizes MHC class II-associated invariant chain (Ii)-derived peptide (CLIP) complexes. MHC class II αβ heterodimers associate early during biosynthesis with a type II membrane protein, the invariant chain (Ii). The invariant chain serves as a chaperone for MHC II molecules and mediates trafficking to the endosomal pathway. In the endosomal pathway Ii is sequentially degraded, leaving a residual CLIP in the peptide-binding groove of MHC II. In presence of antigen peptide fragments, HLA-DM then binds to the MHC II molecule, releasing CLIP and allowing peptides to bind. REA296 detects HLA class II-positive cells which have impaired HLA-DM activity, and tumor cells that have escaped immuno-surveillance by CD4-positive T cells.

Additional information: Clone REA296 displays negligible binding to Fc receptors.