Abstract
Chimeric antigen receptor (CAR)-expressing T cells are a promising therapeutic option for patients with cancer. We developed a new CAR directed against the disialoganglioside GD2, a surface molecule expressed in neuroblastoma and in other neuroectoderm-derived neoplasms. The anti-GD2 single-chain variable fragment (scFv) derived from a murine antibody of IgM class was linked, via a human CD8α hinge-transmembrane domain, to the signaling domains of the costimulatory molecules 4-1BB (CD137) and CD3-ζ. The receptor was expressed in T lymphocytes by retroviral transduction and anti-tumor activities were assessed by targeting GD2-positive neuroblastoma cells using in vitro cytotoxicity assays and a xenograft model. Transduced T cells expressed high levels of anti-GD2 CAR and exerted a robust and specific anti-tumor activity in 4- and 48-hour cultures with neuroblastoma cells. Cytotoxicity was associated with the release of pro-apoptotic molecules such as TRAIL and IFN-γ. These results were confirmed in a xenograft model, where anti-GD2 CAR T cells infiltrating tumors and persisting into blood circulation induced massive apoptosis of neuroblastoma cells and completely abrogated tumor growth. This anti-GD2 CAR represents a powerful new tool to redirect T cells against GD2. The preclinical results of this study warrant clinical testing of this approach in neuroblastoma and other GD2-positive malignancies.
Highlights
Neuroblastoma is the most common extra-cranial solid tumor in young children, appearing at diagnosis in more than half of patients as metastatic disease [1]
The ectodomain of the chimeric antigen receptor (CAR) used in this study was a single-chain variable fragment derived from a mouse IgM anti-GD2 MoAb in which heavy (VH) and light (VL) variable fragments were joined by 18 amino acids encoding the linker sequence, allowing the correct folding of the antigen binding site [12]
The scFv sequence was fused with the human CD8α derived hinge-transmembrane domain that connects to a signal transduction domain, consisting of 4-1BB and CD3-ζ (Fig. 1A)
Summary
Neuroblastoma is the most common extra-cranial solid tumor in young children, appearing at diagnosis in more than half of patients as metastatic disease [1]. Survival rates for patients with low and intermediate-risk neuroblastoma have progressively improved but the prognosis for those disseminated or high-risk diseases remains poor [2]. Because of its high surface expression on tumor cells and low expression on normal tissues, GD2 has been a target for the development of immunotherapeutic monoclonal antibodies [7]. Starting from these encouraging clinical results, anti-GD2 antibody therapy is included in many frontline protocols for neuroblastoma [3, 8]. CAR T cells directed against CD19 have produced dramatic clinical responses in patients with B cell malignancies [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
