T-cells

• T-cells are another type of white blood cell
• T-cells have receptor proteins on its surface that bind to complementary antigens presented to it by phagocytes
• the T-cell binding to the complementary antigen activates it to respond in some way
• helper T-cells release chemical signals that activate and stimulate phagocytes and cytotoxic T-cells which kill abnormal and foreign cells
• helper T-cells also activate B-cells