A new publication from researchers at National Institute for Bioprocessing Research and Training (NIBRT) and University College Dublin has been published in the International Journal of Molecular Sciences, examining strategies to improve the translation efficiency of CAR-encoding mRNA in T cells.
The study, titled “m6A-Modified Nucleotide Bases Improve Translation of In Vitro-Transcribed Chimeric Antigen Receptor (CAR) mRNA in T Cells,” investigates how RNA modifications influence the expression of chimeric antigen receptors following delivery of in vitro-transcribed (IVT) mRNA to T cells. The work, led by Nga Lao and colleagues including Niall Barron, focuses on the role of N6-methyladenosine (m6A) modifications in enhancing CAR protein production.
While CAR-T cell therapies are most commonly generated using viral vectors that integrate genetic material into the genome, mRNA-based approaches provide a non-integrating alternative that enables transient expression and greater flexibility for advanced cell engineering strategies. However, the relatively short stability of IVT mRNA can limit protein expression levels.
In this study, the researchers identified multiple m6A modification motifs within a CD19-CAR mRNA sequence and showed that these modifications enhance mRNA translation efficiency. Inhibition of the m6A methyltransferase METTL3 reduced CAR expression, while mutation of the identified consensus motifs similarly resulted in lower CAR protein levels in T cells from multiple donors.
These findings highlight the importance of m6A in stabilising and enhancing CAR expression from IVT-derived mRNA and indicate that this modification can occur within the cell cytoplasm, suggesting that targeted in vitro chemical modification during mRNA manufacturing may not be necessary.
Please read the full publication here: https://pubmed.ncbi.nlm.nih.gov/41596444/
