Novel In Vitro Assays Pave Way for More Potent Anti-Cancer CAR T-Cell Therapies

Research paper overview and breakthrough in CAR T-cell potency assessment against GBM

The research paper ‘Label-free in vitro assays predict the potency of anti-disialoganglioside chimeric antigen receptor T-cell products’ authored by Meghan Logun and a team of researchers demonstrates a breakthrough in assessing the potency of CAR T-cell therapies against glioblastoma (GBM), a type of solid tumor.

Chimeric antigen receptor (CAR) T cells have shown significant effectiveness against hematological cancers. However, their efficacy against solid tumors such as GBM has been less consistent. The researchers have now created a high-throughput, label-free in vitro testing platform using cellular impedance sensing to measure the potency of CAR T-cells against GBM.

They used two types of gene transfer to create CAR T-cell products: retroviral transduction and virus-free CRISPR-editing. These CAR T-cells were designed to target the disialoganglioside (GD2) antigen, present in abundance on GBM stem cells. The scientists evaluated the potency of these CAR T-cell products against patient-derived GBM stem cells over periods of 2 days and 7 days in vitro.

The results indicated that CAR T-cells created with virus-free CRISPR-editing displayed faster tumor cell killing activity compared to retrovirally transduced CAR T-cells. This faster action was also associated with an increased release of inflammatory cytokines and increased presence of CD8+ CAR T-cells in co-culture conditions. Additionally, the virus-free CRISPR-edited CAR T-cells were more successful in infiltrating three-dimensional GBM spheroids.

Alongside the cytotoxicity assay, the researchers also used endpoint flow cytometry, cytokine analysis, and metabolomics data. Computational modeling indicated that increased tumor necrosis factor alpha (TNFa) concentrations along with decreased glutamine, lactate, and formate were most predictive of short-term and long-term CAR T-cell potency against GBM stem cells.

This study underscores the potential of cellular impedance sensing as a high-throughput, label-free assay for potency testing of CAR T-cells against solid tumors. It provides a foundation for further research in this direction and highlights the potential of using virus-free CRISPR-editing techniques for engineering CAR T-cell products. These findings could be a stepping stone towards the development of more potent CAR T-cell therapies for GBM and other solid tumors.

References:

Logun M, Colonna MB, Mueller KP, Ventarapragada D, Rodier R, Tondepu C, Piscopo NJ, Das A, Chvatal S, Hayes HB, Capitini CM, Brat DJ, Kotanchek T, Edison AS, Saha K, Karumbaiah L. Label-free in vitro assays predict the potency of anti-disialoganglioside chimeric antigen receptor T-cell products. Cytotherapy. 2023 Jun;25(6):670-682. doi: 10.1016/j.jcyt.2023.01.008. Epub 2023 Feb 26. PMID: 36849306; PMCID: PMC10159906.

Authors: Meghan Logun, Maxwell B. Colonna, Katherine P. Mueller, Divya Ventarapragada, Riley Rodier, Chaitanya Tondepu, Nicole J. Piscopo, Amritava Das, Stacie Chvatal, Heather B. Hayes, Christian M. Capitini, Daniel J. Brat, Theresa Kotanchek, Arthur S. Edison, Krishanu Saha, Lohitash Karumbaiah