Enhancing anti-EGFRvIII CAR T cell therapy against glioblastoma with a paracrine SIRPγ-derived CD47 blocker
Nature Communications, 2024
Martins T., Kaymak D., Tatari N., Gerster F., Hogan S., Ritz M., Sabatino V., Wieboldt R., Bartoszek E., McDaid M., Gerber A., Buck A., Beshirova A., Heider A., Shekarian T., Mohamed H., Etter M., Schmassmann P., Abel I., Boulay J., Saito Y., Mariani L., Guzman R., Snijder B., Weiss T., Läubli H., Hutter G.
| Disease area | Application area | Sample type | Products |
|---|---|---|---|
Oncology Immunotherapy | Pathophysiology | Mouse Plasma |  Olink Target 96 |
Abstract
A significant challenge for chimeric antigen receptor (CAR) T cell therapy against glioblastoma (GBM) is its immunosuppressive microenvironment, which is densely populated by protumoral glioma-associated microglia and macrophages (GAMs). Myeloid immune checkpoint therapy targeting the CD47-signal regulatory protein alpha (SIRPα) axis induces GAM phagocytic function, but CD47 blockade monotherapy is associated with toxicity and low bioavailability in solid tumors. In this work, we engineer a CAR T cell against epidermal growth factor receptor variant III (EGFRvIII), constitutively secreting a signal regulatory protein gamma-related protein (SGRP) with high affinity to CD47. Anti-EGFRvIII-SGRP CAR T cells eradicate orthotopic EGFRvIII-mosaic GBM in vivo, promoting GAM-mediated tumor cell phagocytosis. In a subcutaneous CD19+ lymphoma mouse model, anti-CD19-SGRP CAR T cell therapy is superior to conventional anti-CD19 CAR T. Thus, combination of CAR and SGRP eliminates bystander tumor cells in a manner that could overcome main mechanisms of CAR T cell therapy resistance, including immune suppression and antigen escape.