Production of proteins in glutamine-free cell culture media

What is this patent about?

’983 is related to the field of mammalian cell culture and the large-scale recombinant production of proteins. Specifically, it addresses the optimization of nutrient media used during the production phase of host cells, such as Chinese Hamster Ovary (CHO) cells, to improve the yield and quality of therapeutic glycoproteins like antibodies.

The underlying idea behind ’983 is that eliminating glutamine from the production medium—while simultaneously providing a high concentration of asparagine—overcomes the metabolic limitations typically associated with glutamine-free cultures. While glutamine is a standard energy and nitrogen source, its metabolism generates ammonia, a cytotoxic byproduct that limits culture longevity. The inventor discovered that by substituting glutamine with asparagine supplementation, the cells maintain high viability and productivity without the inhibitory effects of ammonia accumulation.

The claims of ’983 focus on a process and a corresponding culture medium that are entirely glutamine-free but contain asparagine at a specific concentration range of 7.5 mM to 15 mM. This specific range is critical for supporting the production phase of a mammalian host cell, ensuring that the cell can synthesize necessary components and maintain protein expression levels in the absence of exogenous glutamine.

In practice, the invention is implemented during the production phase of a fed-batch or continuous culture process. By utilizing this specialized medium, the metabolic profile of the host cell is redistributed to favor the synthesis of the target polypeptide. This shift results in a measurable increase in specific productivity and final protein titer compared to traditional media formulations that rely on glutamine as a primary nitrogen source.

This approach differs from prior methods that either included glutamine as an essential ingredient or attempted to replace it with glutamate, which often led to slower growth rates. By focusing on the asparagine-supplemented glutamine-free environment, the invention achieves a unique balance that extends culture longevity and enhances the overall efficiency of manufacturing complex therapeutic proteins and antibodies.