A universal transgene silencing approach in baculovirus-insect cell system

Area of Science:

• Molecular Biology
• Biotechnology
• Insect Science

Background:

• Baculovirus-insect cell systems (BICS) are highly efficient eukaryotic gene expression platforms.
• BICS are utilized for producing recombinant baculoviruses as biopesticides with enhanced insect toxicity.
• Developing a universal gene silencing (UGS) system is crucial for RNA interference (RNAi) studies in BICS.

Purpose of the Study:

• To establish and evaluate a UGS system for RNAi in BICS.
• To assess the efficacy of small interfering RNA (siRNA) and inverted repeats (IR-EG) in targeting specific mRNAs.
• To investigate the stability and efficiency of gene silencing in both infected and uninfected insect cells.

Main Methods:

• Utilized enhanced green fluorescent protein (EGFP) as a target sequence fused to an insect neurotoxin gene (LqqIT2).
• Examined siRNA and IR-EGFP for targeting EL-fusion and LE-bicistronic mRNAs for degradation.
• Assessed transient and stable suppression efficiencies in Sf9 insect cells, both infected and uninfected.

Main Results:

• RNAi demonstrated significant suppression of target mRNA, with persistence observed for 4 days in infected and 8 days in uninfected Sf9 cells.
• Bicistronic mRNA approaches proved efficient for gene silencing, maintaining the protein of interest's biological activity.
• Both siRNA and IR-EG effectively targeted and degraded fusion and bicistronic mRNAs.

Conclusions:

• The developed UGS system is effective for gene silencing in BICS, applicable to various gene targets.
• Bicistronic mRNA strategies offer a cost-effective and efficient method for gene silencing in insect cell systems.
• This research provides a valuable tool for advancing RNAi applications in baculovirus-mediated gene expression and biopesticide development.