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Updated: Jun 16, 2025
Intracranial Cannula Implantation for Serial Locoregional Chimeric Antigen Receptor CAR T Cell Infusions in Mice
Published on: February 24, 2023
CAR T-cell-mediated delivery of bispecific innate immune cell engagers for neuroblastoma
Guillem Pascual-Pasto1, Brendan McIntyre1, Margaret G Hines2
1Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
Abstract:
Novel chimeric antigen receptor (CAR) T-cell approaches are needed to improve therapeutic efficacy in solid tumors. High-risk neuroblastoma is an aggressive pediatric solid tumor that expresses cell-surface GPC2 and GD2 with a tumor microenvironment infiltrated by CD16a-expressing innate immune cells. Here we engineer T-cells to express a GPC2-directed CAR and simultaneously secrete a bispecific innate immune cell engager (BiCE) targeting both GD2 and CD16a. In vitro, GPC2.CAR-GD2.BiCE T-cells induce GPC2-dependent cytotoxicity and secrete GD2.BiCE that promotes GD2-dependent activation of antitumor innate immunity. In vivo, GPC2.CAR-GD2.BiCE T-cells locally deliver GD2.BiCE and increase intratumor retention of NK-cells. In mice bearing neuroblastoma patient-derived xenografts and reconstituted with human CD16a-expressing immune cells, GD2.BiCEs enhance GPC2.CAR antitumor efficacy. A CAR.BiCE strategy should be considered for tumor histologies where antigen escape limits CAR efficacy, especially for solid tumors like neuroblastoma that are infiltrated by innate immune cells.
Insights
This study introduces a novel CAR T-cell therapy for neuroblastoma, combining GPC2-targeting CARs with a bispecific engager (BiCE) that activates innate immune cells. This dual approach enhances anti-tumor efficacy in preclinical models.
Area of Science:
- Immunology
- Oncology
- Biotechnology
Background:
- High-risk neuroblastoma, a pediatric solid tumor, requires novel therapeutic strategies.
- Existing chimeric antigen receptor (CAR) T-cell therapies face challenges in solid tumor efficacy.
- Neuroblastoma expresses GPC2 and GD2, and its microenvironment contains CD16a-expressing innate immune cells.
Purpose of the Study:
- To engineer T-cells with a GPC2-directed CAR that simultaneously secrete a bispecific innate immune cell engager (BiCE).
- To evaluate the efficacy of this dual-action CAR T-cell therapy in preclinical neuroblastoma models.
Main Methods:
- Engineered T-cells to express a GPC2-directed CAR and secrete a bispecific engager (GD2.BiCE) targeting GD2 and CD16a.
- Assessed in vitro cytotoxicity and innate immune cell activation.
- Evaluated in vivo anti-tumor efficacy in neuroblastoma patient-derived xenografts in mice.
Main Results:
- GPC2.CAR-GD2.BiCE T-cells demonstrated GPC2-dependent cytotoxicity and promoted innate immune cell activation.
- In vivo, the therapy enhanced intratumoral retention of NK-cells and improved anti-tumor efficacy.
- The bispecific engager enhanced the efficacy of GPC2.CAR T-cells in a humanized mouse model.
Conclusions:
- A CAR.BiCE strategy offers a promising approach for solid tumors like neuroblastoma.
- This approach may overcome antigen escape limitations and leverage innate immunity for enhanced therapeutic outcomes.
- Consideration of CAR.BiCE for histologies with antigen escape and innate immune cell infiltration is warranted.
