CAR Signaling Informs Mechanisms to Enhance Metabolism and Function in γδ T Cells | JoVE Visualize

Area of Science:

Immunology
Cell Biology
Biotechnology

Background:

Chimeric antigen receptor (CAR)-T cell therapy, primarily using alpha beta (αβ) T cells, shows efficacy against various cancers.
Gamma delta (γδ) T cells offer potential advantages for immunotherapy, but their distinct biology necessitates specific CAR design.
Existing CAR constructs are largely optimized for αβ T cells, raising questions about their optimal function in γδ T cells.

Purpose of the Study:

To systematically compare the function and phenotype of γδ and αβ T cells engineered with a second-generation PSCA-targeting CAR (PSCA-8t28z).
To identify molecular differences influencing CAR-T cell function between γδ and αβ T cell subsets.
To develop strategies for enhancing γδ CAR-T cell efficacy through tailored receptor engineering.

Main Methods:

Comparative analysis of γδ and αβ T cells transduced with a PSCA-targeting CAR (PSCA-8t28z).
System-level phosphoproteomic analysis to identify differential signaling pathways.
Functional assays to assess cytotoxicity, metabolism (glycolysis, oxidative phosphorylation), and transcription factor activation (AP-1).
Design and testing of a novel synthetic co-stimulatory receptor.

Main Results:

Both γδ and αβ CAR-T cells demonstrated comparable cytotoxicity against PSCA-expressing targets.
γδ CAR-T cells exhibited distinct phenotypes, lower glycolytic and oxidative phosphorylation capacity, and weaker Activator Protein 1 (AP-1) activation compared to αβ CAR-T cells.
Thioredoxin-Interacting Protein was identified as a potential target to enhance γδ T cell metabolism.
A novel synthetic co-stimulatory receptor improved γδ CAR-T cell AP-1 activation and in vivo persistence.

Conclusions:

Fundamental biological differences exist between γδ and αβ T cells that impact CAR-T cell function.
Cell type-specific engineering strategies are crucial for maximizing the therapeutic potential of γδ CAR-T cells.
Tailored CAR architectures and co-stimulatory receptor design can enhance γδ CAR-T cell metabolism, activation, and persistence for improved cancer immunotherapy.