Protein Expression

Infection Kinetics Monitoring® (IKM®)

Rudimentary use of baculovirus infection as a tool for protein expression entered the commercial market in kit format during the late 1980s and became a mainstream tool for recombinant protein production in the 1990s. Infection Kinetics Monitoring®, a registered process tool/technology since 2007, was invented at Blue Sky in 2004 as a means to improve upon the efficiency, consistency, and output of the process of baculovirus-mediated protein expression in insect cells. As the name suggests, the platform uses cell monitoring data, and this data is transformed into a smarter analytics for every step of the process.

The process for insect expression historically takes 5–7 weeks from entry plasmid to baculovirus production to bulk infection and expression. Using IKM® Blue Sky has shorted this cycle time to 3–5 weeks. In addition to the time value IKM® extends to clients, the platform obviates the need for cumbersome viral titration, standardizes conditions for enhanced control (lower lot-to-lot variability), and when used for scouting protein output levels can help triangulate the factors necessary for highest output per volume of insect cell culture. Blue Sky has built a veritable “conveyor belt” through its labs around this process and is achieving strong economies that it passes along to clients.

IKM® is unmatched in the marketplace on differentiating factors such as turnaround time and value-added quality. This service is the bedrock for insect expression and probably plays a role in 50–60% of all Blue Sky projects.

Titerless Infected Cell Preservation & Scale-Up / Baculovirus Infected Insect Cell (TIPS/BIIC)

TIPS/BIIC was developed at Pfizer Inc. by Ed Lee, Dave Wasilko, and William Hermans toward the end of the 1990s and started as a Blue Sky service to Pfizer in 2003. William Hermans is a co-inventor on a patent that was filed but not pursued by Pfizer (therefore the technology was made public). The basis of the technology is to (1) use the insect cell as a storage vehicle in cryopreservation and (2) use the cryostock of infected cells as inocula for recombinant protein expression. Blue Sky asserts that it has created a differentiated platform by improving methodologies using TIPS/BIIC and IKM® technology tools.

BIIC stocks are useful for at least one decade after cryopreservation, yielding exact results for protein expression regardless of whether it is Year 1 or Year 10. In contrast, traditional baculovirus particles lose infectivity over time when stored outside the cell, hence making it difficult to write standardized protocols for protein production. The addition of TIPS/BIIC to Blue Sky’s platform allows clients to improve the reliability of baculovirus-mediated expression results.

EVolution Accelerated™ (EVA™)

The use of mammalian cell lines expressing recombinant proteins was introduced in the 1980s with the advent of recombinant DNA technology, and the popularity of this system continues to grow. First, many biotherapeutics require certain modifications that cannot be achieved in non-mammalian expression systems. Second, there are new technologies that increase production by 1–2 orders of magnitude. Third, stable cell lines can be cryopreserved and utilized for long term production purposes. Fourth, there are improved media free of animal products, which is important for GMP production. However, most cell lines are grown in media containing bovine serum and in many cases it is desirable to adapt the cell lines to growth in defined media. The standard approach for adapting cell lines to a new medium is to gradually wean cell lines to the new medium, a process that can take several months to over one year.

Blue Sky Biotech has implemented a process that accelerates the media adaptation process by selecting for genetic changes in cell lines that allow them to grow more readily in new media. The process reduces the development time frame from several months to weeks. The process was co-developed by Ed Lee and William Hermans and is currently a trade secret. To our knowledge, other CROs use the traditional weaning approach.