Increasing Ornithine Accumulation To Increase High Mannose Glycoform Content Of Recombinant Proteins

What is this patent about?

’963 is related to the field of recombinant protein production, specifically addressing the challenge of controlling the glycosylation patterns of therapeutic glycoproteins produced in cell culture. Glycosylation, the addition of sugar molecules to proteins, significantly impacts a drug's efficacy, safety, and stability. Variations in glycosylation, particularly the levels of high mannose glycoforms, can affect a protein's pharmacokinetic properties and immunogenicity, making their control crucial for biopharmaceutical manufacturing.

The underlying idea behind ’963 is that the intracellular concentration of ornithine within the host cell directly influences the high mannose glycoform content of the recombinant glycoprotein being produced. By manipulating ornithine metabolism within the cell, one can effectively control the levels of these high mannose structures on the protein. This is achieved by either increasing or decreasing ornithine accumulation through various metabolic interventions.

The claims of ’963 focus on a method for increasing the high mannose glycoform content of a recombinant protein. This involves culturing a host cell expressing the recombinant protein in a cell culture medium supplemented with either ornithine or arginine . The key aspect is that this supplementation leads to an increase in ornithine production within the host cell, resulting in a recombinant protein with a higher high mannose glycoform content compared to a cell culture without these supplements.

In practice, the invention works by exploiting the metabolic pathways involving ornithine. Adding ornithine directly increases its concentration, while adding arginine, a precursor to ornithine, boosts its production via the enzyme arginase. This elevated ornithine level then affects the glycosylation machinery within the cell, leading to the addition of more high mannose structures to the recombinant protein. The patent suggests that this may be due to changes in pH within the Golgi apparatus, where glycosylation occurs, or through disruption of redox homeostasis.

This approach differentiates itself from prior methods by directly targeting ornithine metabolism as a means of controlling glycosylation. While previous studies have shown that cell culture conditions can influence glycosylation, ’963 provides a specific and actionable strategy for manipulating high mannose glycoform content by modulating ornithine levels. This is achieved through the addition of specific compounds like ornithine or arginine, offering a more targeted and potentially predictable way to engineer the glycosylation profile of therapeutic proteins.