The 17A2 monoclonal antibody specifically reacts with the mouse T lymphocytes receptor (TCR) associated CD3 complex, resulting in cellular activation and proliferation. CD3 is expressed by thymocytes and mature lymphocytes, and contains γ, δ, and ε subunits, involved in the assembly, trafficking, and surface expression of T-cell receptor complex.

The interaction between the T lymphocytes and the 17A2 antibody can be blocked by the 145-2C11 anti-CD3e antibody, demonstrating that the 17A2 antibody recognizes the CD3 ε chain.