Post-translational protein modifications in antigen recognition and autoimmunity

It is estimated that 50-90% of the proteins in the human body are posttrans lationally modified. In the proper context, these modifications are necessa ry for the biological functions of a vast array of proteins and the effecto r functions of the cells in which they reside. However, it is now clear tha t some post-translational modifications can create new self antigens (Ags) or even mask Ags normally recognized by the immune system. In either case,t hey profoundly affect the recognition of Ag by bone marrow-derived cells, a s well as their effector functions. How do post-translational protein modif ications affect the processing of foreign and self Ags and what is their ro le in the origin of autoimmune responses?