Lipid nanoparticles outperform electroporation in mRNA-based CAR T cell engineering

Area of Science:

• Immunotherapy
• Cellular Engineering
• Nanomedicine

Background:

• Chimeric antigen receptor (CAR) T cell therapy shows efficacy in hematological malignancies.
• Current CAR T cell therapies rely on viral transduction, which is costly, time-consuming, and carries safety concerns.
• Direct CAR mRNA delivery to T cells is a promising alternative, with electroporation (EP) currently used but yielding suboptimal anti-tumor responses.

Purpose of the Study:

• To evaluate lipid nanoparticles (LNPs) as a novel ex vivo delivery method for CAR mRNA into T cells.
• To compare the efficacy of LNP-mediated CAR mRNA delivery against traditional electroporation (EP).
• To assess the potential of mRNA-LNP delivery as a next-generation transient CAR T cell engineering strategy.

Main Methods:

• Engineered T cells expressing chimeric antigen receptors (CARs) were generated using both lipid nanoparticles (LNPs) and electroporation (EP) for CAR mRNA delivery.
• In vitro efficacy, CAR-mRNA persistence, CAR expression levels, and T cell proliferation were compared between LNP- and EP-treated cells.
• CAR T cells derived from both methods were assessed for functionality and exhaustion markers.

Main Results:

• LNP-mediated CAR mRNA delivery resulted in significantly prolonged in vitro efficacy compared to EP.
• LNP-treated CAR T cells exhibited extended CAR-mRNA persistence and CAR expression due to a less cytotoxic delivery mechanism.
• mRNA-LNP-derived CAR T cells demonstrated comparable in vitro functionality to stably transduced CAR T cells but showed reduced exhaustion.

Conclusions:

• Lipid nanoparticles (LNPs) represent a superior method for ex vivo CAR mRNA delivery to T cells, outperforming electroporation (EP).
• The LNP approach facilitates enhanced CAR T cell persistence, functionality, and reduced exhaustion, offering a promising transient engineering strategy.
• mRNA-LNP delivery holds significant potential for advancing clinical CAR T cell therapies as a safer and more efficient alternative to viral transduction.