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

Abstract

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 CT3derived 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 CAR T cell proliferation and persistence. These studies demonstrate how RNA-seq data can be exploited to help identify tumorassociated exons that can be targeted by CAR T cell therapies.

Highly active CAR T cells that bind to a juxtamembrane region of mesothelin and are not blocked by shed mesothelin

“…CAR T cells that contain the variable fragment (Fv) of mAb 15B6 were produced using the vector developed by the M.H. laboratory ( 23 ). In this construct an Fv in which the light chain precedes the heavy chain is fused to a CD8 hinge ( Fig.…”

“…Assays were performed as previously described ( 23 ). The binding kinetics were performed using the Octet RED96 system (FortéBio) at the Biophysics core at National Heart, Lung, and Blood Institute.…”

The Road to CAR T-Cell Therapies for Pediatric CNS Tumors: Obstacles and New Avenues

“…One promising strategy to overcome the paucity of true neoantigens is to target oncofetal antigens, a class of cell surface markers normally expressed exclusively during prenatal tissue development that can become re-expressed during neoplastic transformation (20). For example, CAR T-cells have been developed to target tumor-specific exons of the oncofetal antigen cerebroglycan GPC2 (21,22). Alternatively, they can be made to target tumor-specific antigen epitopes.…”

GPC2 Is a Potential Diagnostic, Immunological, and Prognostic Biomarker in Pan-Cancer

“…A research identified immunotherapy targets in 12 pediatric cancers, and GPC2 was analyzed in 8 diseases such as osteosarcoma (OS) and Ewing sarcoma (EWS), which makes it evident that GPC2 has a wide range of functions in childhood cancers ( 20 ). Some papers consider that it keeps silent relatively in various adult normal tissues such as brain, heart, lung, and kidney ( 9 , 21 ). However, small-cell lung cancer and prostate cancer were discovered to have an upregulated expression ( 17 , 22 ).…”