Immunological Barriers to Stem Cell Therapy in the Central Nervous System

Figure 2

MHC II antigen presentation pathway. MHC II is synthesized in the endoplasmic reticulum (ER) as a heterodimer (𝛼, 𝛽). MHC II proteins are also bound to the invariant chain protein (IC), which inhibits the binding of peptides to the MHC II proteins. IC is cleaved after the exocytic vesicles fuse with the acidic lysosomes to form class II invariant chain protein (CLIP). These MHC II proteins bind to small peptides (10–30 a.a.) in the vesicle and appear on the cell surface when these vesicles fuse with the plasma membrane.