Figure 2.

Activation of T cells by BiTEs. To induce activation of and cytotoxic activity by a T cell, a BiTE protein must engage both a T cell and a tumor cell simultaneously, so single cell binding to a T cell or a tumor cell causes no activation. Simultaneous binding of multiple BiTE molecules to both T cell and tumor cell promotes the formation of an immunological synapse leading to T cell activation and release of cytokines and cytotoxicity of the tumor cell.