Citrullination and autophagy

During evolution, the eukaryotic cells develop different processes in order to adapt themselves to environmental changes, as well as to die or to survive. These processes include apoptosis, NETosis, and autophagy: citrullination is implicated in all of these physiological mechanisms. Autophagy plays a crucial role in physiology and pathophysiology, such as aging, infectious diseases, cancer, and perturbations in autophagy have also been implicated in autoimmune diseases. It was demonstrated that autophagy was involved in the generation of citrullinated peptides by antigen presenting cells (APCs), with increased peptidyl arginine deiminase activity detected in purified autophagosomes. Self-peptides post-translationally modified by a process such as citrullination would possibly form neo-antigens that are recognized by APCs of the immune system and thus represent a potential target for autoimmunity.