An in vivo CRISPR screen unveils promising target genes to improve CAR-T cell efficacy in a solid tumor model

Area of Science:

• Immunology
• Cancer Biology
• Gene Therapy

Background:

• Chimeric antigen receptor T (CAR-T) cell therapy shows promise for hematological malignancies but faces challenges with patient response durability and efficacy against solid tumors.
• Poor CAR-T cell persistence is a key factor limiting therapeutic success, necessitating strategies to enhance in vivo expansion.
• Comparative studies are needed to identify the most effective gene-editing strategies for improving CAR-T cell persistence.

Purpose of the Study:

• To identify and validate gene targets for enhancing the persistence of EGFR CAR-T cells in a preclinical model of human lung cancer.
• To compare the effects of various gene-editing strategies on CAR-T cell persistence in a context-specific manner.

Main Methods:

• Utilized a focused CRISPR-Cas9 knockout (CRISPR-KO) library targeting 50 gene candidates.
• Employed a competitive screening approach in human lung tumor-bearing mice to assess CAR-T cell persistence.
• Evaluated the impact of specific gene disruptions on EGFR CAR-T cell efficacy.

Main Results:

• Disruption of REGNASE-1, SOCS1, PTPN2, and P16INK4A significantly improved the persistence of EGFR CAR-T cells.
• Conversely, disruption of MED12, PRDM1, and BATF had detrimental effects on CAR-T cell persistence in this specific model.
• Demonstrated that gene-editing outcomes are context-dependent, with some strategies yielding unexpected negative impacts.

Conclusions:

• REGNASE-1, SOCS1, PTPN2, and P16INK4A are robust targets for enhancing CAR-T cell persistence in EGFR-driven lung cancers.
• Context-specific evaluation of genetic modifications is essential for optimizing CAR-T cell therapies.
• Findings underscore the need for careful validation of gene-editing strategies to accelerate clinical translation and improve patient outcomes.