This project will investigate and compare the differential expression of different classes of proteins, namely antibodies and coagulation factors. Expression of antibodies is well characterised, with consistent yields of 3 g/L or better in optimised conditions. Commercial production of antibodies is therefore a fairly generic process. Conversely, coagulation factors are extremely difficult to express at high levels and each factor represents a unique manufacturing challenge. The project seeks to understand what cell machinery / processing mechanisms create the bottlenecks in production of recombinant coagulation factors. 9, 10 The project will involve metabolomic analysis, as well as protein and cell engineering. A successful outcome to this project will lead to yield improvements for the commercial production of recombinant coagulation factors (and potentially other therapeutic proteins), resulting in improved productivity and reduced manufacturing costs.

The majority of proteins generated by the Recombinant Protein Group within CSL to date for in vivo use are mAbs that are not dependent on post-translational modifications for activity. However, CSL now has several projects that are not antibody-focussed and require the generation of complex proteins, including FVII-HSA, FVIII, AAT and C1Inhibitor. The correct glycosylation and, in particular, sialylation of these recombinant therapeutic proteins are important for in vivo animal studies, as glycostructures can influence the pharmacokinetics and immunogenicity of the protein.11 The project aims to understand the effect of host cell line, manipulation of enzymes in the protein glycosylation pathway and culture conditions on glycostructures in recombinant therapeutic proteins. The project will also compare proteins expressed in the Wave Bioreactor to those in a stirred tank bioreactor, with respect to posttranslational modifications and quality.