B7-H3.CAR-NK cells secreting anti-PD-L1 scFv

**B7-H3.CAR-NK cells secreting anti-PD-L1 scFv** is an investigational **NK cell therapy** in which natural killer (NK) cells are engineered to express a **chimeric antigen receptor (CAR)** targeting **B7-H3** (CD276), a B7 family immune checkpoint overexpressed on many solid tumors and associated with poor prognosis. These CAR-NK cells are additionally modified to secrete a **single-chain variable fragment (scFv)** against **PD-L1**, enabling localized blockade of the PD-1/PD-L1 axis to counteract tumor immune evasion and enhance T cell activity within the tumor microenvironment. The dual-targeting approach combines direct tumor lysis via B7-H3 recognition (typically incorporating 4-1BB costimulatory and CD3ζ signaling domains) with indirect immune potentiation, addressing limitations of standard CAR-NK therapies like limited persistence and checkpoint-mediated suppression. Developed as an "off-the-shelf" cellular immunotherapy, it shows promise for **solid tumors** such as glioblastoma and other B7-H3-positive malignancies, with preclinical evidence of robust cytotoxicity against tumor cells.