Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>Glioblastoma remains one of the deadliest cancers despite aggressive treatment, which is why novel therapeutic approaches are urgently needed. Chimeric antigen receptor (CAR) T cell therapy has demonstrated significant success in the field of hematological malignancies. However, treating glioblastoma with this type of therapy is more difficult for several reasons such as the lack of suitable target antigens. Here, we generated a second-generation CAR construct targeting the transmembrane protein CD317 (BST-2, HM1.24), which is expressed by human glioma cell lines in vitro as well as in vivo. We demonstrate strong anti-glioma activity of CD317-CAR T cells against different glioma target cells with varying CD317 expression levels. Glioma cells harboring a CRISPR/Cas9-mediated CD317 knockout were not susceptible for these CAR T cells, demonstrating their target antigen-specificity. CD317 is also expressed on T cells and transduction with a CD317-directed CAR impaired expansion of T cells due to residual CD317 expression and subsequent fratricide. Therefore, we silenced CD317 in the transduced T cells by co-expressing the CAR construct with a specific shRNA, which significantly increased the viability, proliferation and cytotoxicity of the CAR T cells. Finally, we observed strong anti-glioma activity of CD317-CAR T cells in clinically relevant orthotopic xenograft glioma mouse models resulting in prolonged survival of CAR T cell-treated animals. Taken together, these data reveal a promising role of CD317 as a novel target for CAR T cell therapy in glioblastoma and warrant further evaluation of this strategy in clinical neuro-oncology.</jats:p>