CAR T cells targeting tumor-associated exons of glypican 2 regress neuroblastoma in mice

Targeting solid tumors must overcome several major obstacles, in particular, the identification of elusive tumor-specific antigens. Here, we devise a strategy to help identify tumor-specific epitopes. Glypican 2 (GPC2) is overexpressed in neuroblastoma. Using RNA sequencing (RNA-seq) analysis, we show that exon 3 and exons 7-10 of GPC2 are expressed in cancer but are minimally expressed in normal tissues. Accordingly, we discover a monoclonal antibody (CT3) that binds exons 3 and 10 and visualize the complex structure of CT3 and GPC2 by electron microscopy. The potential of this approach is exemplified by designing CT3-derived chimeric antigen receptor (CAR) T cells that regress neuroblastoma in mice. Genomic sequencing of T cells recovered from mice reveals the CAR integration sites that may contribute to CART cell proliferation and persistence. These studies demonstrate how RNA-seq data can be exploited to help identify tumor-associated exons that can be targeted by CAR T cell therapies.

Automated summary

The study utilized RNA sequencing analysis to identify high expression of GPC2 exons 3 and exons 7-10 in cancer but minimal expression in normal tissues. A monoclonal antibody CT3 was discovered and used to design CAR T cells for treating neuroblastoma. Genomic sequencing of T cells recovered from mice revealed potential CAR integration sites contributing to CART cell proliferation and persistence.