Targeting bladder cancer using activated T cells armed with bispecific antibodies.

In the present study, we aimed to investigate whether EGFR or HER2 may serve as a target for T cell-mediated immunotherapy against human bladder cancer. Expression of EGFR and HER2 was detected on the surface of bladder cancer cells, including Pumc-91 and T24 cells, and their chemotherapeutic drug-resistant counterparts. Activated T cells (ATCs) were generated from healthy PBMCs that were stimulated by the combination of anti-CD3 monoclonal antibody and anti‑CD28 monoclonal antibody in the presence of interleukin-2 for 14 days. The ATCs were then armed with chemically hetero-conjugated anti-CD3xanti-EGFR (EGFRBi-Ab) or anti-CD3xanti-HER2 (HER2Bi-Ab). The specific cytolytic activity of ATCs armed with EGFRBi-Ab or HER2Bi-Ab against human bladder cancer cells was evaluated by lactate dehydrogenase activity assays in vitro. In contrast to unarmed ATCs, EGFRBi-Ab-armed ATCs and HER2Bi-Ab-armed ATCs showed increased cytotoxic activity against bladder cancer cells. Moreover, Bi-Ab-armed ATCs expressed higher levels of activating marker CD69 and secreted more IFN-γ, TNF-α and IL-2 than did unarmed ATCs. EGFRBi-Ab- or HER2Bi-Ab-armed ATCs may provide a promising immunotherapy for bladder cancer.