Engineering CAR-T cells to overcome glycosylation-driven tumour resistance

Introduction

T cells engineered to express tumour-specific chimeric antigen receptors (CAR) proved effective against B-cell tumours. However, as the technology moves to solid cancers, clinical responses have not been as robust.

Challenges in Solid Tumours

In this setting, several barriers need to be overcome, including:

• Poor tumour recognition
• A highly immunosuppressive tumour microenvironment (TME)

Altered glycosylation is a hallmark of cancer, often manifesting as incomplete synthesis of O-glycans and increased branching of N-glycans. Glycosylation can mask epitopes to antibody recognition and suppress anticancer immunity.

Previous Findings

My Unit was the first to report that N-glycans protect tumours from CAR-T cells and that pharmacological inhibition of N-glycosylation improves the efficacy of CAR-T cell therapy in solid malignancies.

Proposed Solution

With the aim of generating a single cell product able to safely offset multiple barriers of tumour resistance, I propose to engineer CAR-T cells to locally express an enzyme able to de-glycosylate tumour and TME cells.

Methodology

This goal will be achieved through:

1. The selection of a mutant able to deglycosylate the surface proteome of target cells.
2. Regulating its function in CAR-T cells by testing different systems based on:
   • The use of specific promoters
   • The inclusion of artificial miRNA target sequences
   • The generation of a transmembrane variant

Characterization and Model

A deep characterization of the selected product will be performed in mice reconstituted with a human haemopoietic system. This model will allow us to study:

• The efficacy and safety of the proposed approach
• Its ability to remodel the TME toward a pro-inflammatory state

Conclusion

I believe that this project will have an immediate impact on cancer immunotherapy, will fuel the development of antiviral approaches, and will provide new technological platforms. I have a deep knowledge of CAR-T cell therapy and have established a great network in the field. Despite being ambitious, I believe I have the right skills and tools to make this project a reality.