GD2-Specific CAR T Cells Demonstrate Potent and Targeted Anti-Tumor Efficacy Against Melanoma In Vitro and In Vivo.

Background: Disialoganglioside (GD2) is a tumor-associated antigen that is highly expressed in various neuroectodermal cancers, including melanoma. While chimeric antigen receptor (CAR) T-cell immunotherapy has demonstrated remarkable success in treating hematologic neoplasms, the identification of suitable targets remains a major obstacle in translating this approach to solid tumors.

Methods: Peripheral blood T lymphocytes from six healthy donors were used to generate GD2-specific CAR T cells via retroviral transduction. The resulting GD2.CAR T cells were characterized by NanoString transcriptome profiling, flow cytometry with hierarchical stochastic neighbor embedding (HSNE) dimensionality reduction, and in vitro cytotoxicity assays against GD2⁺ and GD2^- melanoma cell lines. In vivo experiments were also performed using GD2⁺ xenograft models and a single intratumoral dose of 8 × 10⁶ GD2.CAR T cells.

Result: The GD2.CAR T cell population exhibited a predominantly naive phenotype (CD8⁺CD40L⁺CD69^‒CD107a⁺4-1BB⁺FasL⁺) and effective anti-tumor mechanisms involving the granzyme A/B axis, the Fas/FasL axis, and cytokine release. Transcriptome analysis revealed transduction-related effects on proliferation and a shift towards an effector phenotype during early co-culture with tumor cells, accompanied by upregulation of interferon-gamma (IFN-γ) and cytokine signaling genes. GD2.CAR T cells demonstrated robust cytotoxicity against GD2⁺ melanoma cells in vitro, while significant in vivo tumor control was observed in xenograft models.

Conclusion: GD2.CAR T cells demonstrate potent anti-tumor activity against melanoma in vitro and in vivo, highlighting their therapeutic potential and warranting further clinical investigation.