Nuclear Antigens and Auto/Alloantibody Responses: Friend or Foe in Transplant Immunology

Figure 4

The balance of autoimmunity and alloimmunity (against alloantigens, pathogens, or allergens) is important for immune regulation. During the rejection phase (or when suffering from infection, injury, or allergy), alloimmunity is predominant, and nuclear antigens such as histones and HMGB1 are released from damaged cells, tissues, or organs or are actively secreted from activating immune cells such as DCs and macrophages. The induction of autoimmunity against nuclear antigens (i.e., induction of antinuclear Abregs) may regulate the balance and induce immunological tolerance. Excessive activation of autoimmunity may cause autoimmune disorders.