This strategy could be a powerful therapeutic option for repairing damaged heart muscle, preventing chronic heart failure. To realize this project, a safe and efficient production platform for hHGF is required.
HGF has been expressed from a number of expression systems, including insect cells, HEK, and CHO cells, with rather low yields of approximately 1 mg/L up to 13 mg/L (achieved after gene-amplification) (Figure 3D).
With our stable transfection and cloning protocols, we could easily identify HGF expressing CAP single cell clones that clearly outperform the so far published mammalian expression systems (Figure 3D). Twenty-two out of 30 analyzed HGF-expressing CAP cell clones yielded more than 10 mg/L of HGF (Figure 3A).
In fedbatch processes, after 9–11 days, product titers above 60 mg/L of fully intact, glycosylated pro-HGF were reproducibly obtained (Figure 3B).
Moreover, the serum-free chemically defined culture conditions ensure that only the unprocessed single chain pro-HGF is present in the cell culture supernatants (Figure 3C). In other words, a uniform product, which is easy to purify and to activate by endogenous factors present in fetal bovine serum or human serum, is generated.