Human endoglin-CD3 bispecific T cell engager antibody induces anti-tumor effect .

Endoglin, also known as CD105, is a homo-dimeric membrane glycoprotein required for angiogenesis and serves as a marker for cancer vasculature. In this study, we constructed a bispecific T-cell engager (BiTE) antibody that targets human endoglin and CD3 (hEND-CD3/BiTE). We examined BiTE binding to endoglin-expressing cells and its effects on the cytolytic activity of T cells and cancer development. The effects of hEND-CD3/BiTE, including binding to target cells, T-cell activation, proliferation, and cytotoxicity, were examined in endoglin-expressing 293T cells, human umbilical vascular endothelial cells, tumor-derived endothelial cells, and CD3 T cells. An xenograft tumor model was established using A549 human lung cancer cells. The therapeutic efficacy of hEND-CD3/BiTE was assessed by monitoring tumor growth, angiogenesis, and mouse survival. hEND-CD3/BiTE specifically bound to endoglin-expressing cells and CD3 T cells and stimulated T-cell activation, proliferation, and Th1 cytokine secretion, and promoted T-cell-mediated cytolysis of endoglin-expressing cells. The hEND-CD3/BiTE caused minimal toxicity to major organs, reduced tumor neoangiogenesis, inhibited tumor growth, and significantly improved mouse survival. Our study demonstrated the therapeutic potential of hEND-CD3/BiTE and provided a novel approach to clinical cancer treatment.