Chlorotoxin-directed CAR T cells for specific and effective targeting of glioblastoma
Menée à l'aide de xénogreffes orthotopiques de glioblastome, cette étude met en évidence l'intérêt thérapeutique de lymphocytes CAR-T exprimant un récepteur composé de CD3 epsilon, de CD28, du fragment Fc de l'immunoglobuline IgG4 et de la chlorotoxine, un peptide présent dans le venin de scorpion et capable de se lier spécifiquement aux cellules de glioblastome
Chlorotoxin derived from scorpion venom has previously been shown to bind glioblastoma cells. Wang et al. designed a chimeric antigen receptor (CAR) based on chlorotoxin to surmount limitations of other glioblastoma-targeted CARs that have not been able to overcome tumor heterogeneity and antigen escape. They demonstrated that chlorotoxin binding captures a broader array of primary tumors than staining for previously identified antigenic targets. Chlorotoxin-directed CAR T cells were safe in mice and induced regression of orthotopic glioblastoma xenografts with no evidence of antigen escape. These toxin-based CAR T cells are distinct from conventional CAR design and could one day be used to deliver a poisonous blow to glioblastoma.Although chimeric antigen receptor (CAR) T cells have demonstrated signs of antitumor activity against glioblastoma (GBM), tumor heterogeneity remains a critical challenge. To achieve broader and more effective GBM targeting, we developed a peptide-bearing CAR exploiting the GBM-binding potential of chlorotoxin (CLTX). We find that CLTX peptide binds a great proportion of tumors and constituent tumor cells. CAR T cells using CLTX as the targeting domain (CLTX-CAR T cells) mediate potent anti-GBM activity and efficiently target tumors lacking expression of other GBM-associated antigens. Treatment with CLTX-CAR T cells resulted in tumor regression in orthotopic xenograft GBM tumor models. CLTX-CAR T cells do not exhibit observable off-target effector activity against normal cells or after adoptive transfer into mice. Effective targeting by CLTX-CAR T cells requires cell surface expression of matrix metalloproteinase–2. Our results pioneer a peptide toxin in CAR design, expanding the repertoire of tumor-selective CAR T cells with the potential to reduce antigen escape.