Immune Cells Exhaustion

During chronic infections, a distinct physiological condition named “exhaustion” arises that is associated with the dysfunctionality in immune cells and their eventual removal from the environment, which evidently help the progress of infection or tumors in human or animal bodies. This state of immune cells could be  under  the  control  of  different  elements  such  as  the  antigen  load,  help  from  inhibitory  cells,  lack  of costimulatory  signals  and  etc.  Exhaustion  that  has  been  found  in  different  immune  system  cells,  is  usually accompanied by impaired effector function and proliferation of immune cells, poor memory recall, upregulation of  inhibitory  molecules,  compromised  metabolism  and  altered  transcription  program,  and  is  considered  a reversible process, unlike other physiological states like anergy or senescence, organized through the blockage of several factors. Although theemergence of these cells in viral infections and cancer is an undesirable event, the  importance  of  the  presence  ofexhaustedcells  in  autoimmune  diseases  and  organ  transplantation  is highlighted  as  a  positive  change.  In  this  review,  we  aimed  to  determine the  occurrence  of  this  process  in different immune cells, the characteristics obtained by these cells, effective and primitive factors on exhaustion, metabolic  and  transcriptional  cell  changes,  and  the  use  of  these  cells  in  autoimmune  diseases  and  organ transplantation