Method of Producing Factor VIII Proteins by Recombinant Methods
Provided herein are methods and compositions for producing Factor VIII proteins. Such methods include introducing into a cell a nucleic acid molecule encoding a Factor VIII protein operably linked to a promoter, wherein the promoter is characterized by the ability to produce commercially viable Factor VIII protein; and incubating the cell under conditions for producing commercially viable Factor VIII protein. Also provided are nucleic acid molecules which encode a Factor VIII protein operably linked to a Chinese hamster elongation factor 1-α (CHEF1) promoter, which may be used in the methods provided herein.
1 . A method for producing a recombinant Factor VIII protein, comprising the steps of:
introducing into a cell a nucleic acid molecule encoding a Factor VIII protein operably linked to a promoter, wherein the promoter is characterized by the ability to produce commercially viable Factor VIII protein; and
incubating the cell under conditions for producing Factor VIII protein.
2 . The method of claim 1 , wherein the cell is a mammalian cell.
3 . The method of claim 2 , wherein the mammalian cell is selected from the group consisting of a COS-1, CHO, and HEK 293 cell.
4 . The method of claim 1 , wherein the nucleic acid molecule comprises a cDNA which encodes the Factor VIII protein.
5 . The method of claim 1 , wherein the nucleic acid molecule is operably linked to a Chinese hamster elongation factor 1-α (CHEF1) promoter.
6 . The method of claim 1 , wherein the Factor VIII protein comprises a deletion of the B-domain starting at Arg 740 when the protein is aligned with the wild-type Factor VIII, followed by an addition of an amino acid spacer containing at least one N-linked glycosylation site, wherein the amino acid spacer containing the at least one N-linked glycosylation site facilitates the secretion or expression of the B-domain-deletion Factor VIII protein.
7 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 750 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 226 amino acid spacer containing 6 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
8 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 769 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 29 amino acid spacer containing one N-linked glycosylation site, thereby partially replacing the B domain of the modified Factor VIII protein.
9 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 794 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 55 amino acid spacer containing 2 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
10 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 857 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 117 amino acid spacer containing 3 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
11 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 903 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 163 amino acid spacer containing 4 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
12 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 946 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 206 amino acid spacer containing 5 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
13 . The method of claim 6 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 1009 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 269 amino acid spacer containing 8 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
14 . The method of claim 1 wherein the Factor VIII protein comprises a heterologous sequence.
15 . A method for identifying a cell expressing commercially viable Factor VIII protein, comprising:
a) introducing into cells a nucleic acid molecule encoding a Factor VIII protein operably linked to a promoter, wherein the promoter is characterized by the ability to produce commercially viable Factor VIII protein;
b) incubating the cells under conditions for producing Factor VIII protein;
c) selecting clones expressing high levels of FVIII relative to the other clones;
d) recloning the cells selected in step c); and
e) identifying at least one subclone expressing a higher level of FVIII relative to those selected in step c).
16 . A nucleic acid molecule encoding a Factor VIII protein operably linked to a Chinese hamster elongation factor 1-α (CHEF1) promoter.
17 . The nucleic acid molecule of claim 16 , wherein the nucleic acid molecule comprises a cDNA which encodes the Factor VIII protein.
18 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises a deletion of the B-domain starting at Arg 740 when the protein is aligned with the wild-type Factor VIII, followed by an addition of an amino acid spacer containing at least one N-linked glycosylation site, wherein the amino acid spacer containing the at least one N-linked glycosylation site facilitates the secretion or expression of the B-domain-deletion Factor VIII protein.
19 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 750 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 226 amino acid spacer containing 6 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
20 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 769 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 29 amino acid spacer containing one N-linked glycosylation site, thereby partially replacing the B domain of the modified Factor VIII protein.
21 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 794 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 55 amino acid spacer containing 2 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
22 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 857 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 117 amino acid spacer containing 3 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
23 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 903 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 163 amino acid spacer containing 4 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
24 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 946 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 206 amino acid spacer containing 5 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
25 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises an amino acid sequence inserted at position 1009 when the protein is aligned with the wild-type Factor VIII, the inserted amino acid sequence consisting of a 269 amino acid spacer containing 8 N-linked glycosylation sites, thereby partially replacing the B domain of the modified Factor VIII protein.
26 . The nucleic acid molecule of claim 16 , which encodes a heterologous protein.
27 . The method of claim 15 further comprising:
f) recloning the at least one subclone identified in step e); and
g) identifying at least one subclone expressing a higher level of FVIII relative to the at least one subclone selected in step e).
28 . The method of claim 1 , wherein the Factor VIII protein comprises a deletion of the B-domain starting at Arg 740 when the protein is aligned with the wild-type Factor VIII.
29 . The method of claim 1 , wherein the Factor VIII protein comprises a substitution of phenylalanine at position 309 to serine when the protein is aligned with the wild-type Factor VIII.
30 . The method of claim 28 , wherein the Factor VIII protein comprises a substitution of phenylalanine at position 309 to serine when the protein is aligned with the wild-type Factor VIII.
31 . The nucleic acid molecule of claim 16 , wherein the Factor VIII protein comprises a deletion of the B-domain starting at Arg 740 when the protein is aligned with the wild-type Factor VIII.
32 . The nucleic acid molecule of claim 16 wherein the Factor VIII protein comprises a substitution of phenylalanine at position 309 to serine when the protein is aligned with the wild-type Factor VIII.
33 . The nucleic acid molecule of claim 31 wherein the Factor VIII protein comprises a substitution of phenylalanine at position 309 to serine when the protein is aligned with the wild-type Factor VIII.
34 . The method of claim 1 wherein the Factor VIII protein is produced at a level selected from the group consisting of at least about 20 IU/mL, at least about 30 IU/mL, at least about 40 IU/mL, at least about 50 IU/mL, at least about 60 IU/mL, at least about 70 IU/mL, at least about 80 IU/mL, at least about 90 IU/mL, at least about 100 IU/mL, at least about 110 IU/mL, at least about 120 IU/mL, at least about 130 IU/mL, at least about 140 IU/mL, at least about 150 IU/mL, at least about 160 IU/mL, at least about 170 IU/mL, at least about 180 IU/mL, at least about 190 IU/mL, at least about 200 IU/mL, and at least about 210 IU/mL.