NSUN2 rewires metabolism to support protein secretion and enhance bioproduction output

The production of bioactive materials such as viral vectors and neutralizing antibodies for research and clinical applications has realized an exponential increase in demand. Stable cell lines, such as HEK-293FT and CHO cells, that support virus-based packaging of genetic material and are readily modified to support protein and antibody production. NSUN2 is an RNA methyltransferase that modifies tRNA and mRNA substrates altering their stability, localization, and function. While NSUN2 has been well-characterized in its role of regulating innate immune activity in response to active infection promoting the virus life cycle, its potential role as a tool in bioproduction has not been explored. In the current study, we have identified NSUN2 as a novel target to aid bioproduction processes. We demonstrated that CHO cells upregulate NSUN2 in high-performing clones and that overexpressing NSUN2 significantly enhanced pembrolizumab production. Further, overexpressing NSUN2 in HEK293FT cells transcriptomically enriched for genes in the unfolded protein response and protein secretion pathways. Functionally, we demonstrated that cells overexpressing NSUN2 generated significantly higher viral titers, improving transduction efficiency and lowering the input requirement. Mechanistically, we observed that NSUN2 activity reprograms metabolism enabling fuel flexibility, resistance to nutrient depletion, and UDP-GlcNAc production. Proteomic analysis of purified viral particles showed a significant enrichment in N-Glycans on particles produced with NSUN2-overexpressing cells. Considering the widespread use of these systems in basic research and production of FDA-approved therapies, overexpressing NSUN2 offers an approach that can optimize producer cells to improve yields, making these tools and therapies more accessible.