Bioprocess applications of a Sindbis virus-based temperature-inducible expression system

Area of Science:

• Biotechnology
• Molecular Biology
• Virology

Background:

• Inducible expression systems are crucial for producing toxic proteins.
• Low basal expression and high inducibility are key system requirements.
• The pCytTS Sindbis virus replicon system offers temperature-regulatable expression.

Purpose of the Study:

• To evaluate the pCytTS system for bioprocess applications.
• To optimize selection of stable transfected clones for high protein expression.
• To assess the production of interferon beta (beta-IFN) using this system.

Main Methods:

• Utilized green fluorescent protein for clone selection optimization.
• Constructed clones for producing interferon beta (beta-IFN).
• Analyzed temperature-dependent beta-IFN production in various culture formats (adherent, suspension, hollow fiber).

Main Results:

• Achieved specific expression levels of 1.0 x 10^5 IU/10^6 cells/day in suspension cultures.
• Reached over 1.5 x 10^6 IU/mL/day in hollow fiber reactors.
• Purified beta-IFN was highly glycosylated with high specific activity and showed no significant mutations in mRNA after 10 days.

Conclusions:

• The pCytTS system is suitable for bioprocess applications.
• High-quality glycoproteins can be produced using this inducible expression system.
• The system demonstrates applicability in diverse reactor settings.