Interleukin-7 expression by CAR-T cells improves CAR-T cell survival and efficacy in chordoma.

Chordoma is a rare bone tumor that frequently recurs after surgery, and the prognosis is poor with current treatments. This study aimed to identify potential novel immunotherapeutic targets for chordomas by identifying target proteins in clinical samples as well as tumor microenvironmental factors to enhance efficacy. Fourteen chordoma samples were analyzed by single-cell RNA sequencing, and B7-H3 and IL-7 were identified as potential targets and potentiators, respectively. B7-H3-targeted chimeric antigen receptor T (CAR-T) cells and B7-H3 CAR-T cells expressing IL-7 were synthesized and their anti-tumor activity evaluated in vitro, including in primary chordoma organoid models. The B7-H3 CAR-T/IL-7 therapy showed enhanced cytotoxicity and prolonged duration of action against tumor cells. Additionally, IL-7 modulated favorable subpopulations of cultured CAR-T cells, diminished immune checkpoint expression on T-cell surfaces, and enhanced T-cell functionality. The incorporation of IL-7 molecules into the B7-H3 CAR structure augmented CAR-T-cell function and improved CAR-T-cell efficacy, thus providing a novel dual therapeutic strategy for chordoma treatment.

Complex immune microenvironment of chordoma: a road map for future treatment.

BACKGROUND: Chordoma, a rare bone tumor, presents limited treatment options and patients typically exhibit poor survival outcomes. While immunotherapy has shown promising results in treating various tumors, research on the immune microenvironment of chordomas is still in its early stages. Therefore, understanding how the immune microenvironment of chordomas influences the outcomes of immunotherapy is crucial. METHODS: We employed single-cell RNA sequencing (scRNA-seq), bulk RNA-seq, CellChat, gene set variation analysis, as well as calculation of immune features to further dissect the complex immune microenvironment of chordoma. RESULTS: Previous research by van Oost et al argued that compared with other sarcomas, chordomas typically exhibit an immunologically "hot" microenvironment, a conclusion with which we concur based on their research findings. Additionally, the authors suggest that T cell-mediated immunotherapy is feasible for the majority of chordomas. However, we are inclined to categorize them as an immune-excluded phenotype according to the latest classification methods, rather than persisting with the concepts of "cold" and "hot". Unlike them, we explored immune infiltration scores (IS), T lymphocyte scoring (TLS), and human leucocyte antigen class I (HLA-I) using Bulk RNA-seq data from 126 chordoma patients and found that higher IS, TLS, and higher HLA-I expression were associated with poorer patient prognosis. Additionally, CellChat analysis of scRNA-seq results from six chordoma patients revealed no direct interaction between T cells and tumor cells. CONCLUSIONS: These findings suggested that the efficacy of T cell-based immunotherapy may be limited or even ineffective for patients with chordoma.

Single-cell sequencing reveals VEGFR as a potential target for CAR-T cell therapy in chordoma.

BACKGROUND: Chordomas are rare osseous neoplasms with a dismal prognosis when they recur. Here we identified cell surface proteins that could potentially serve as novel immunotherapeutic targets in patients with chordoma. METHODS: Fourteen chordoma samples from patients attending Xuanwu Hospital Capital Medical University were subjected to single-cell RNA sequencing. Target molecules were identified on chordoma cells and cancer metastasis-related signalling pathways characterised. VEGFR-targeting CAR-T cells and VEGFR CAR-T cells with an additional TGF-ß scFv were synthesised and their in vitro antitumor activities were evaluated, including in a primary chordoma organoid model. RESULTS: Single-cell transcriptome sequencing identified the chordoma-specific antigen VEGFR and TGF-ß as therapeutic targets. VRGFR CAR-T cells and VEGFR/TGF-ß scFv CAR-T cells recognised antigen-positive cells and exhibited significant antitumor effects through CAR-T cell activation and cytokine secretion. Furthermore, VEGFR/TGF-ß scFv CAR-T cells showed enhanced and sustained cytotoxicity of chordoma cell lines in vitro compared with VRGFR CAR-T cells. CONCLUSIONS: This study provides a comprehensive single-cell landscape of human chordoma and highlights its heterogeneity and the role played by TGF-ß in chordoma progression. Our findings substantiate the potential of VEGFR as a target for CAR-T cell therapies in chordoma which, together with modulated TGF-ß signalling, may augment the efficacy of CAR-T cells.