Filamentous fungi have long been safe production hosts for antibiotics and other natural product pharmaceuticals. In addition, some strains have been developed to produce complex proteins such as enzymes and other polypeptides at extremely high levels (in excess of 50 g/L, 5-10 fold higher than the best yeast systems) for food, feed, pulp and paper, and other commodity uses.
NeuBIOS™ as a 'plug and play' Neurospora Biological Operating System for production of protein biologics combines specially developed strains of Neurospora crassa with paired expression plasmids and serves as the starting point for specific product production. To adapt the platform for the production of recombinant heterologous proteins, a variety of versatile and proprietary tools has been developed.
One of the most important tools is the use of heterokaryons, which are single N. crassa strains that contain a mixture of two or more genetically distinct nuclei, with each nucleus containing a gene for a different heterologous protein. This allows the production of flexible combinations of subunit heteromeric proteins such as monoclonal antibodies. The heterokaryon approach can also be applied to produce multivalent viral vaccine mixtures. The ratio of each set of nuclei in the heterokaryon can be artificially and stably set allowing the empirical "tuning" of the expression levels of the subunits by effectively changing the gene dosage.
To summarize the advantages of the Neugenesis platform:
- The basic platform produces a variety of biologics.
- Avoids entangling patent issues (Cabilly II patent).
- High production yield potential.
- Development times for new products as short as 12 weeks.
- Reduced capital requirements: bioreactors <1000 liters.
- Short fermentation time (<7 days).
- Minimal media and simplified protein recovery.
- Tailored multivalent vaccines – mix and match antigens.
- Ability to store production strains for rapid reintroduction to the manufacturing stream.
- Scalability and flexibility.
- Non-pathogenic host organisms.
- Protein refolding is rarely an issue.
- Glycosylation is more mammalian than bacterial systems.
- For influenza vaccine production:
- 5 weeks to generate a strain expressing a new variant.
- 7 weeks from cell bank to harvest of bulk product.
