The focus of this study was on breast cancer, where a protein called folate receptor alpha (FRα) is highly expressed in cancer cells, making it a potential target for ACT. To explore the potential of SmartDC technology in breast cancer treatment, the researchers engineered SmartDC cells to express the FRα antigen (SmartDC-FRα) to activate FRα-specific T lymphocytes.

The researchers took human primary monocytes and transduced them with lentiviruses containing complementary DNA sequences encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4), and FRα, creating SmartDC-FRα. Autologous T lymphocytes were then activated by coculturing them with SmartDC-FRα. The activated T lymphocytes demonstrated significantly enhanced cytotoxicity against breast cancer cell cultures expressing FRα. Impressively, up to 84.9% of MDA-MB-231 and 89.7% of MCF-7 breast cancer cell lines expressing FRα were specifically lysed by the activated T lymphocytes at a specific effector-to-target ratio.

Furthermore, the cytotoxicity of T lymphocytes activated by SmartDC-FRα was demonstrated in three-dimensional (3D) spheroid cultures of FRα-expressing breast cancer cells. The T lymphocytes induced size reduction and disruption of the spheroids, indicating their ability to target and destroy cancer cells in a three-dimensional environment.

This pioneering study highlights the potential of using T lymphocytes activated by SmartDC-FRα in the treatment of breast cancer expressing FRα. By harnessing the power of the immune system, this novel approach offers new hope in the fight against breast cancer and paves the way for further advancements in targeted cell-based therapies.