Hhmi: Bio Interactive: Cloning an Army of T Cells for Immune Defense

View this video/animation to see how one type of immune cell-the helper T cell-interprets a message presented at the surface of the cell membrane. The message is an antigen, a protein fragment taken from an invading microbe. A series of events unfolds that results in the production of many clones of the helper T cell. These identical T cells can serve as a brigade forming an essential communication network to activate B cells, which make antibodies that will specifically attack the activating antigen. [4.21]