Suppression

• Suppressor T cells keep the immune system from acting until a normal immune response can benefit the body. Immune responses, which include fever and swelling, attempt to rid the body of pathogens and are beneficial only as a reaction to an external attack. Immune responses that occur without provocation are harmful to cells.
  
  

Protection

• Autoimmune diseases, such as lupus or rheumatoid arthritis, occur when your immune system attacks your body by mistake. Suppressor T cells protect you from these conditions by keeping your immune system deactivated until it is needed.
  
  

Mechanism

• According to the National Institutes of Health, suppressor T cells function by weakening the "cytolitic" or destructive effects of immune system cells. This is done by directly killing the immune cells, inhibiting the secretions of immune cells and secreting proteins that alter the immune cell functions.
  
  

Destruction

• A laboratory team at the University of California, San Francisco recently discovered that suppressor T cells are sometimes converted to "memory T cells," which attack healthy cells instead of protecting them. This conversion is the result of defective "FoxP3" protein production in the suppressor T cells.
  
  

Imitation

• The treatments for autoimmune diseases that result from suppressor T cell defects include immune suppression and T cell replacement. Immune suppression is achieved with drugs such as corticosteroids or cyclophosphamide, which mimic the normal behaviors of suppressor T cells. Some patients require blood or bone marrow transfusions to increase their suppressor T cell count.