Targeting GD2-positive glioblastoma by chimeric antigen receptor empowered mesenchymal progenitors

Abstract

Tumor targeting by genetically modified mesenchymal stromal/stem cells (MSCs) carrying anti-cancer molecules represents a promising cell-based strategy. We previously showed that the pro-apoptotic agent tumor necrosis factor-related apoptosisinducing ligand (TRAIL) can be successfully delivered by MSCs to cancer sites. While the interaction between TRAIL and its receptors is clear, more obscure is the way in which MSCs can selectively target tumors and their antigens. Several neuroectoderm-derived neoplasms, including glioblastoma (GBM), sarcomas, and neuroblastoma, express high levels of the tumor-associated antigen GD2. We have already challenged this cell surface disialoganglioside by a chimeric antigen receptor (CAR)-T cell approach against neuroblastoma. With the intent to maximize the therapeutic profile of MSCs delivering TRAIL, we here originally developed a bi-functional strategy where TRAIL is delivered by MSCs that are also gene modified with the truncated form of the anti-GD2 CAR (GD2 tCAR) to mediate an immunoselective recognition of GD2-positive tumors. These bi-functional MSCs expressed high levels of TRAIL and GD2 tCAR associated with a robust anti-tumor activity against GD2-positive GBM cells. Most importantly, the anti-cancer action was reinforced by the enhanced targeting potential of such bi-functional cells. Collectively, our results suggest that a truncated anti-GD2 CAR might be a powerful new tool to redirect MSCs carrying TRAIL against GD2-expressing tumors. This affinity-based dual targeting holds the promise to combine site-specific and prolonged retention of MSCs in GD2-expressing tumors, thereby providing a more effective delivery of TRAIL for still incurable cancers.

Design and Characterization of an “All-in-One” Lentiviral Vector System Combining Constitutive Anti-GD2 CAR Expression and Inducible Cytokines

“…As proof-of-concept, we generated a modular "all-in-one" vector system based on clinically applied third generation lentiviral self-inactivating (SIN) vectors designed to constitutively express a CAR in combination with NFAT-inducible cytokine expression, for example, IL12 or IL18. Therefore, we further codon-optimized a well-established second generation CAR that targets the cell-surface disialoganglioside G D2 [25], which has restricted expression in normal tissues, but is expressed on several solid tumors, including glioblastoma [26], neuroblastoma [27], and sarcomas [28]. Clinical trials already support the safety and efficacy of G D2 -redirected CAR T cells without undesirable adverse effects [29][30][31].…”

IL7-IL12 Engineered Mesenchymal Stem Cells (MSCs) Improve A CAR T Cell Attack Against Colorectal Cancer Cells

“…Upon tumor infiltration, MSCs arrange themselves in close proximity with tumor cells and vasculature [45], making them ideal vehicles for the delivery of cytokines that are picked up by infiltrating immune cells including CAR T cells. There is an ongoing discussion whether the inherent MSCs homing and retention capabilities are sufficient for a lasting therapeutic effect; engineering MSCs with a truncated, non-signaling CAR was applied in order to increase tumor affinity [46] and to improve delivery of therapeutic proteins [47,48]. MSCs were modified for targeting by transduction with a targeting domain like a chimeric receptor targeting EGFRvIII [45,49] and GD2 [46].…”

“…There is an ongoing discussion whether the inherent MSCs homing and retention capabilities are sufficient for a lasting therapeutic effect; engineering MSCs with a truncated, non-signaling CAR was applied in order to increase tumor affinity [46] and to improve delivery of therapeutic proteins [47,48]. MSCs were modified for targeting by transduction with a targeting domain like a chimeric receptor targeting EGFRvIII [45,49] and GD2 [46]. MSCs were engineered with both to deliver TRAIL and to specifically recognize GD2 through a truncated anti-GD2 CAR in order to improve their retention in the targeted GD2 positive tumors like glioblastoma, sarcomas and neuroblastoma [46].…”

“…MSCs were modified for targeting by transduction with a targeting domain like a chimeric receptor targeting EGFRvIII [45,49] and GD2 [46]. MSCs were engineered with both to deliver TRAIL and to specifically recognize GD2 through a truncated anti-GD2 CAR in order to improve their retention in the targeted GD2 positive tumors like glioblastoma, sarcomas and neuroblastoma [46]. These modified MSCs mediate an improved anti-tumor response with a prolonged cell-to-cell interaction and thereby more effectively delivering TRAIL.…”

Genetically engineered T cells for cancer immunotherapy

“…The most commonly used targets for CAR-T therapy are surface antigens, such as carcinoembryonic antigen (CEA) for colorectal adenocarcinoma 175,176 , fibroblast activation protein for malignant pleural mesothelioma 177 , diganglioside GD2 for neuroblastoma 178 , glioblastoma 179 , melanoma 180 , and osteosarcoma 181 , human epidermal growth factor receptor 2 (HER2) for HER2-positive sarcoma 182 , mesothelin for pancreatic cancer 183 , IL-13 receptor α (IL-13Rα) for glioma 184 , and mutant αvβ6 integrin for pancreatic tumors 185 . TCR-engineered T cells always target the p-HLA complex.…”