beeldscherm schreef op 24 oktober 2017 14:43:
CAP-Go.2 cell line: Improved O-glycosylation for significantly prolonged plasma half-life of
human recombinant C1 Inhibitor
N Strempel, S Wissing, J Woelfel, H Kewes, C Niehus, C Bialek, S Hertel, N Faust
CEVEC Pharmaceuticals,, Germany,
The development of therapeutic proteins has accelerated immensely over the past years. However, the
recombinant expression of highly glycosylated therapeutic proteins such as blood coagulation factors or serum
proteins, has remained a challenging task.
C1-Inhibitor (C1-Inh) is glycosylated with 7 N-glycans and 8 O-linked glycans. Plasma derived C1-Inh (Berinert,
Cinryze) as well as recombinant C1-Inh from transgenic rabbits (Ruconest) are approved for the treatment of
acute attacks in patients with hereditary angioedema. However, the recombinant product shows dramatically
reduced plasma half-life in comparison to the plasma-derived versions.
We have developed the CAP-Go protein expression platform, an expression system based on human cells,
to confer optimal glycosylation to complex glycoproteins such as C1-Inh. The CAP-Go.1 cell line has been
modified to facilitate expression of proteins with fully sialylated N-glycans. Recombinant proteins like human
alpha-antitrypsin or human placental alkaline phosphatase produced with CAP-Go.1 show a significantly
prolonged serum half-life in rats. However, expression of rhC1-Inh in CAP-Go.1 cells had no positive impact
on the pharmacokinetic profile.
Expression of rhC1-Inh in CAP-Go.2 cells, which in addition addresses the O-linked glycosylation patterns,
results in a significantly increased serum half-life which is actually indistinguishable from the plasma-purified
protein. O-glycan analysis shows that rhC1-Inh expressed by CAP-Go.2 cells contains only highly sialylated
core1 O-glycan structures, highly comparable to plasma-derived Berinert. Our results demonstrate that in addition
to N-glycosylation, the structure of O-linked glycans plays a crucial role in bioavailability and pharmacokinetic
properties of glycoproteins.
In conclusion, rhC1-Inh expressed from CAP-Go.2 cells, matches serum-derived C1-Inh in all analyzed aspects
- specific activity, serum half-life, and glycosylation pattern - and offers the advantage of being producible at
large scale on a safe platform
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