A cell-based phenotypic library selection and screening approach for the de novo discovery of novel functional
Julie K Fierle1, Johan Abram-Saliba1, Vasileios Atsaves1
1LAbCore Immunoglobulin Discovery Platform, Department of Oncology, Ludwig Institute for Cancer Research Lausanne, University of Lausanne, 1066, Epalinges, Switzerland.
Abstract:
Anti-tumor therapies that seek to exploit and redirect the cytotoxic killing and effector potential of autologous or syngeneic T cells have shown extraordinary promise and efficacy in certain clinical settings. Such cells, when engineered to express synthetic chimeric antigen receptors (CARs) acquire novel targeting and activation properties which are governed and orchestrated by, typically, antibody fragments specific for a tumor antigen of interest. However, it is becoming increasingly apparent that not all antibodies are equal in this regard, with a growing appreciation that 'optimal' CAR performance requires a consideration of multiple structural and contextual parameters. Thus, antibodies raised by classical approaches and intended for other applications often perform poorly or not at all when repurposed as CARs. With this in mind, we have explored the potential of an in vitro phenotypic CAR library discovery approach that tightly associates antibody-driven bridging of tumor and effector T cells with an informative and functionally relevant CAR activation reporter signal. Critically, we demonstrate the utility of this enrichment methodology for 'real world' de novo discovery by isolating several novel anti-mesothelin CAR-active scFv candidates.
Insights
Researchers developed a new method to find better antibody fragments for CAR T-cell therapy. This approach improves the targeting and effectiveness of these advanced anti-tumor treatments.
Area of Science:
- Immunology
- Oncology
- Biotechnology
Background:
- Chimeric antigen receptor (CAR) T-cell therapies leverage T cells for anti-tumor activity.
- CAR function relies on antibody fragments targeting tumor antigens, but not all antibodies perform optimally.
- Repurposed antibodies often show poor efficacy in CAR constructs.
Purpose of the Study:
- To explore an in vitro phenotypic library discovery approach for CAR engineering.
- To identify novel antibody fragments with enhanced CAR activity.
- To optimize CAR T-cell therapy by selecting functionally superior antibody components.
Main Methods:
- Developed a phenotypic CAR library discovery method.
- Associated antibody-tumor cell and T-cell bridging with CAR activation reporter signals.
- Utilized an enrichment methodology for de novo discovery of CAR-active single-chain variable fragments (scFvs).
Main Results:
- Demonstrated the utility of the enrichment methodology for real-world discovery.
- Successfully isolated several novel anti-mesothelin CAR-active scFv candidates.
- Validated the approach for identifying functionally relevant antibody fragments for CARs.
Conclusions:
- The developed in vitro phenotypic approach is effective for discovering optimal CAR components.
- This method facilitates the de novo identification of potent anti-tumor CAR-active scFvs.
- Optimized antibody selection is crucial for enhancing CAR T-cell therapy efficacy.
