Researchers are exploring new strategies to improve the performance of chimeric antigen receptor-natural killer (CAR-NK) cell therapies, and new preclinical data suggest that both receptor architecture and controlled drug exposure may play a role.
In a study published in Frontiers in Immunology, researchers engineered CD19-targeted CAR-NK-92 cells with alternative intracellular signaling configurations and evaluated the impact of short-term exposure to dasatinib, a tyrosine kinase inhibitor. The goal was to determine whether modifying the internal design of the CAR construct, and temporarily modulating signaling activity, could enhance antitumor function.
Across laboratory models, all engineered CAR-NK cells demonstrated antigen-specific killing of CD19-positive leukemia and lymphoma cell lines. Activity against CD19-negative controls remained unchanged, confirming target specificity. While the different construct designs produced broadly comparable tumor-cell killing in vitro, transcriptional profiling suggested that certain configurations engaged NK–associated activation programs differently.
The researchers then examined the effect of transient dasatinib exposure. During active treatment, CAR-NK activity was suppressed. Such reversible control mechanisms are being explored as potential tools to fine-tune cell therapy activity without permanently altering the construct. However, following drug withdrawal, cytotoxicity and cytokine production increased, with the most pronounced functional enhancement observed in cells incorporating 2B4-based signaling elements.
In an NSG mouse xenograft model of CD19-positive leukemia, dasatinib-pretreated CAR-NK cells using a 2B4-based signaling design showed stronger tumor control and prolonged survival than standard versions. The tests showed that these components helped make the cells "ready to attack," thereby increasing their ability to destroy tumors.
The results indicate that performance may depend not only on the chosen target, but also on how the receptor is engineered and regulated. Although conducted in a proof-of-concept NK-92 platform, the study highlights how signaling architecture and reversible pharmacologic modulation could inform the design of next-generation allogeneic NK products.
Newsletters
Receive the latest pharmaceutical news, personalities, education, and career development – weekly to your inbox.
