A new single-step protocol for rapid baculovirus-driven protein production in insect cells

Area of Science:

• Molecular Biology
• Biotechnology
• Protein Expression

Background:

• The Baculovirus expression vector system (BEV) is a widely used eukaryotic system for heterologous protein production.
• Conventional BEV methods face challenges including lengthy recombinant virus generation and potential virus instability.
• Existing protocols require multiple amplification steps after initial transfection.

Purpose of the Study:

• To develop a streamlined, single-step protocol for generating recombinant baculovirus.
• To reduce the time and complexity associated with BEV-based protein expression.
• To assess the efficiency of using P0 virus directly for protein production.

Main Methods:

• Adapted a protocol for transfecting insect cells in suspension using DNA-PEI complexes to generate P0 virus.
• Expressed and purified six target proteins (four intracellular, two secreted) using P0 or P1 virus.
• Compared protein expression levels, purity, and yield between P0 and amplified P1 virus.

Main Results:

• Transfection in suspension proved as efficient as standard methods, yielding high amounts of P0 virus.
• Protein expression levels, purity, and yield were comparable when using P0 virus versus amplified P1 virus.
• The optimized protocol reduced the time from bacmid DNA to protein to eight days.

Conclusions:

• A single-step, transfection-only procedure can efficiently generate recombinant baculovirus for protein expression.
• This method significantly shortens production timelines and mitigates the risk of virus decay.
• Minimal DNA input (100 µg bacmid DNA) is sufficient for large-scale production (10 L).