Design and Characterization of an “All-in-One” Lentiviral Vector System Combining Constitutive Anti-GD2 CAR Expression and Inducible Cytokines
Katharina Zimmermann, Johannes Kuehle, Anna Christina Dragon, Melanie Galla, Christina Kloth, Loreen Sophie Rudek, I. Erol Sandalcioglu, Belal Neyazi, Thomas Moritz, Johann Meyer, Claudia Rössig, Bianca Altvater, Britta Eiz‐Vesper, Michael Morgan, Hinrich Abken, Axel Schambach
Abstract
Genetically modified T cells expressing chimeric antigen receptors (CARs) so far have mostly failed in the treatment of solid tumors owing to a number of limitations, including an immunosuppressive tumor microenvironment and insufficient CAR T cell activation and persistence. Next-generation approaches using CAR T cells that secrete transgenic immunomodulatory cytokines upon CAR signaling, known as TRUCKs (“T cells redirected for universal cytokine-mediated killing”), are currently being explored. As TRUCKs were engineered by the transduction of T cells with two separate vectors, we developed a lentiviral modular “all-in-one” vector system that combines constitutive CAR expression and inducible nuclear factor of activated T cells (NFAT)-driven transgene expression for more efficient production of TRUCKs. Activation of the GD2-specific CAR via GD2+ target cells induced NFAT promoter-driven cytokine release in primary human T cells, and indicated a tight linkage of CAR-specific activation and transgene expression that was further improved by a modified NFATsyn promoter. As proof-of-concept, we showed that T cells containing the “all-in-one” vector system secrete the immunomodulatory cytokines interleukin (IL)12 or IL18 upon co-cultivation with primary human GD2+ tumor cells, resulting in enhanced effector cell properties and increased monocyte recruitment. This highlights the potential of our system to simplify application of TRUCK-modified T cells in solid tumor therapy.