Optimization of a GDNF production method based on Semliki Forest virus vector.

Area of Science:

• Biotechnology
• Neuroscience
• Protein Engineering

Background:

• Human glial cell line-derived neurotrophic factor (hGDNF) is a potent therapeutic candidate for Parkinson's disease (PD).
• Commercialization of hGDNF is hindered by challenges in producing clinical-grade proteins with high purity and specific glycosylation.
• Baby hamster kidney (BHK-21) cells using Semliki Forest virus (SFV) enable high-level hGDNF expression but face limitations due to SFV's temperature-dependent cytopathic effects.

Purpose of the Study:

• To improve the expression and purification of hGDNF.
• To develop a biphasic temperature cultivation protocol to mitigate SFV-induced cytopathic effects.
• To enhance cell survival and therapeutic protein yield.

Main Methods:

• Utilized BHK-21 cells with an SFV-based expression vector for hGDNF production.
• Implemented a biphasic temperature cultivation strategy, including a "shut-off period" and a "recovery period".
• Investigated temperature shifts from 33°C to 37°C during critical phases of cell culture.

Main Results:

• Increasing temperature to 37°C during the shut-off period significantly improved cell survival and hGDNF expression.
• The biphasic protocol resulted in nearly a 3-fold increase in hGDNF production compared to previous methods.
• A recovery period at 37°C prior to returning to 33°C was identified as crucial for viability and yield.

Conclusions:

• The developed biphasic temperature protocol enhances hGDNF expression and cell viability in BHK-21 cells.
• This method offers an efficient and scalable approach for producing highly pure hGDNF for potential PD therapeutics.
• Optimized post-translational modifications and protein folding contribute to the successful production of clinical-grade hGDNF.