Engineering Stable Lentiviral Vector Producer Cells Improves LVV Production

Stable lentiviral vector producer cell lines represent a promising platform for scalable and cost-efficient vector manufacturing, yet their productivity is often limited by intrinsic host-cell constraints. In this study, we aimed to identify cellular factors restricting LVV production in stable doxycycline-inducible GPRTG producer cell lines and to evaluate whether targeted host-cell engineering can improve vector yield. Comparative transcriptomic analysis of high- and low-producing clones revealed distinct differences in cellular pathways related to transcription, translation, energy metabolism, lipid homeostasis, stress response, and chromatin regulation. Based on differential gene expression, candidate genes were modified by CRISPR/Cas9-mediated knockout or overexpression and functionally analyzed in a low-producing clone. Single-gene KO screening identified H1-2, ADAMTS1, INSIG1, GADD45B, and HSPA1B to increase cell-specific LVV productivity up to 2.6-fold, with H1-2 showing the strongest effect. In addition, combinatorial disruption further improved productivity. In contrast, overexpression of selected candidates did not enhance LVV production. Overall, our results demonstrate that transcriptomics-guided host-cell engineering is an effective strategy to identify and relieve intrinsic bottlenecks in stable LVV producer cell lines.