CRISPR/Cas9-Driven Engineering of AcMNPV Using Dual gRNA for Optimized Recombinant Protein Production.

The CRISPR/Cas9 system is a powerful genome-editing tool that is applied in baculovirus engineering. In this study, we present the first report of the AcMNPV genome deletions for bioproduction purposes, using a dual single-guide RNA (sgRNA) CRISPR/Cas9 approach. We used this method to remove nonessential genes for the budded virus and boost recombinant protein yields when applied as BEVS. We show that the co-delivery of two distinct ribonucleoprotein (RNP) complexes, each assembled with a sgRNA and Cas9, into Sf9 insect cells efficiently generated deletions of fragments containing tandem genes in the genome. To evaluate the potential of this method, we assessed the expression of two model proteins, eGFP and HRPc, in insect cells and larvae. The gene deletions had diverse effects on protein expression: some significantly enhanced it while others reduced production. These results indicate that, although the targeted genes are nonessential, their removal can differentially affect recombinant protein yields depending on the host. Notably, HRPC expression increased up to 3.1-fold in <i>Spodoptera frugiperda</i> larvae. These findings validate an effective strategy for developing minimized baculovirus genomes and demonstrate that dual-guide CRISPR/Cas9 editing is a rapid and precise tool for baculovirus genome engineering.