The function of cytotoxic T cells, also called killer T cells or cytotoxic T lymphocytes, is to protect the body from disease and infection. They do so by killing diseased cells.
What Are T Cells?
T cells are white blood cells that are part are the body's immune system. White blood cells defend your body against disease, cancer, infections and foreign substances.
How Cytotoxic T Cells Work
Activated or "turned on" cytotoxic T cells circulate in the blood and lymphatic fluid looking for cells that contain foreign particles (antigens), attach to them and inject a toxic chemical. The cytotoxic T cells become activated when they come into contact with antigen fragments that are attached to specific types of protein.
Other Types of T Cells
In addition to cytotoxic T cells, the body has helper T cells, which detect disease or infection. They call the cytotoxic T cells and suppressor T cells to help, which tell the immune system when the diseased cells are gone and the cytotoxic T cells are no longer needed.
Attacking Diseased Cells
Cytotoxic T cells are the only T cells that can directly attack and kill diseased cells. They also attack cancer cells and foreign cells introduced into the body through blood transfusions or organ transplants.
In addition to killing diseased cells, T cells release chemicals (interleukins) that control the entire immune response. Immune response refers to how your body recognizes and defends itself against harmful organisms and foreign substances. If your body's immune response is not working properly, you are more likely to develop a disease or infection.