Preclinical research results from the University of North Carolina Lineberger Comprehensive Cancer Center have identified a cocktail of three different drugs that can be used to generate CAR-Ts (chimeric antigen receptor T cells) of the immune system more robust in the fight against cancer. This discovery could have a significant impact on improving the production of CAR-T cells for clinical use.
CAR-T cell immunotherapy involves harvesting T cells from a patient’s immune system and genetically restructuring them in the laboratory to recognize targets on the surface of cancer cells when they are reinfused into patients. Patients treated with certain types of CAR-T cells may have significant responses to their cancer, particularly when the engineered cells contain a subset of immune cells identified as memory T stem cells (TGDS).
The research results were published on January 8 in Natural immunology.
CAR-T cells produced in the laboratory for reinfusion can be extremely different from patient to patient and the lack of certain cell types in the final product can significantly reduce the ability of these cells to persist long term. Our study demonstrates that adding the drugs we identified during the reengineering process allows for the preservation of a critical cellular subset responsible for long-term persistence.
Gianpietro Dotti, MD, professor of microbiology and immunology at the UNC School of Medicine and co-leader of the UNC Lineberger Immunology Research Program
Dotti and Yang Xu, PhD, are corresponding authors of the article. Feifei Song, PhD, a postdoctoral researcher at UNC Lineberger, is the first author.
The researchers, using laboratory and mouse experiments, identified several enzymes called kinases (ITK, ADCK3, MAP3K4 and CDK13) involved in the enrichment of TSCM-like CAR-T cells. In particular, ADCK3 and MAP3K4 were found to be potential novel targets in T cells, suggesting that further study of their functions and signaling pathways could reveal insights into how T cells differentiate. or change to perform important immune functions.
The identification of the kinases then allowed scientists to conduct a sophisticated screening process to search for kinase inhibitor drugs that preserve TSCM-like cells in engineered CAR-T cells generated from both healthy donors and affected patients. chronic lymphocytic leukemia (CLL). .
Since targeting a single signaling pathway often triggers compensatory defense mechanisms in cancer cells, researchers reasoned that using multiple kinase inhibitors targeting multiple, non-overlapping pathways could potentially circumvent this compensation and obtain greater enrichment of TSCM in CAR. T cell-based products, improving anti-tumor activity.
The investigators were right.
One of their most striking findings was the inability of a single kinase inhibitor to increase the frequency of certain TSCM-like CAR-T cells. In contrast, the three-drug kinase inhibitor cocktail consistently increased the frequency of TSCM-like CAR-T cells in healthy donors and CLL patients who harbored particularly dysfunctional T cells.
“We tested our hypothesis in CLL because the T cells in these patients are actually dysfunctional cells. The strategy we propose is not suitable for blood-borne malignancies but is a general concept applicable to the manufacturing of CAR-T cells for all diseases,” said Dotti. . “Our study also helps to show the advantages of pharmacological approaches over genetic approaches to enrich TSCM-like cells, as most gene-targeted therapies have not proven to be very effective in this area. »
Dotti and colleagues said additional research is needed to determine how kinase inhibitors actively drive TSCM differentiation before the investigational drug cocktail can be studied in a clinical trial. But they believe their cocktail of kinase inhibitors could be quickly integrated into the manufacture of other T-cell products, such as tumor-infiltrating lymphocytes, also used to fight cancer.
