Arginine inactivation of viruses

1. A method of inactivating or reducing the infectious titer of a retrovirus comprising contacting said virus with arginine, wherein said contacting occurs in a solution comprising at least about 0.2 M arginine and wherein said solution is at a pH above about 6.0.

2. The method of claim 1 , wherein said retrovirus contaminates a therapeutic biological product.

3. The method of claim 1 , wherein said pH is selected from the group consisting of

a) pH of about 6.0 to about 8.5;

b) pH of about 6.5 to about 8.0;

c) pH of about 6.5 to about 7.5;

d) pH of about 6.0 to 8.0;

e) pH of about 7.0 to about 8.0;

f) pH of about 7.0 to about 7.5;

g) pH of about 6.0;

h) of about 6.5;

i) pH of about 7.0;

j) pH of about 7.5;

k) pH of about 8.0; and,

l) pH of about 8.5.

4. The method of claim 1 , wherein said concentration arginine is selected from the group consisting of:

a) about 0.3 M;

b) about 0.4 M;

c) about 0.5 M;

d) about 0.6 M;

e) about 0.7 M;

f) about 0.8 M;

g) about 0.9 M;

h) about 1.0 M;

i) about 1.1 M;

j) about 1.2 M;

k) about 1.3 M;

l) about 1.4 M;

m) about 1.5 M;

n) about 1.6 M;

o) about 1.7 M;

p) about 1.8 M;

q) about 1.9 M;

r) about 2.0 M;

s) about 2.1 M;

t) about 2.2 M;

u) about 2.3 M;

v) about 2.4 M;

w) about 2.5 M;

x) about 3 M;

y) about 3.5 M;

z) about 4 M;

aa) about 4.5 M;

ab) about 5 M;

ac) about 5.5 M;

ad) about 6 M;

ad) about 6.5 M;

ad) about 7 M; and

ae) about 7.5 M.

5. The method of claim 1 , wherein said retrovirus is contacted with said solution that further comprises a glycol compound.

6. The method of claim 5 , wherein said glycol compound is present at a concentration of less than or equal to about 50% (weight to volume).

7. The method of claim 5 , wherein said glycol compound is selected from the group consisting of:

a) propylene glycol;

b) polypropylene glycol;

c) ethylene glycol;

d) polyethylene glycol;

e) hexylene glycol; and,

f) polyhexylene glycol.

8. The method of claim 1 , wherein said inactivating or reducing is performed as part of a product purification process.

9. The method of claim 8 , wherein said inactivating or reducing is performed during a cell culture harvest procedure.

10. The method of claim 8 , wherein said inactivating or reducing is performed during a cell culture clarification procedure.

11. The method of claim 2 , wherein said inactivating or reducing is performed prior to a chromatography purification procedure, wherein said chromatography purification procedure comprises contacting said retrovirus contaminated therapeutic biological product with a chromatographic media.

12. The method of claim 2 , wherein said inactivating or reducing is performed subsequent to a chromatography purification procedure, wherein said chromatography purification procedure comprises contacting said retrovirus contaminated therapeutic biological product with a chromatographic media.

13. The method of claim 2 , wherein said inactivating or reducing is performed subsequent to one or more chromatography purification procedures but prior to another or more chromatography purification procedures, wherein said chromatography purification procedures comprise contacting said retrovirus contaminated therapeutic biological product with a chromatographic media.

14. The method of claim 2 , wherein said inactivating or reducing is performed subsequent to all chromatography purification procedures used in preparing said retrovirus contaminated therapeutic biological product.

15. The method of claim 8 , wherein said inactivating or reducing is performed prior to a virus filtration procedure.

16. The method of claim 8 , wherein said inactivating or reducing is performed subsequent to a virus filtration procedure.

17. The method of claim 8 , wherein said inactivating or reducing is performed subsequent to a virus filtration procedure and prior to an ultrafiltration or diafiltration procedure.

18. The method of claim 8 , wherein said inactivating or reducing is performed prior to an ultrafiltration or diafiltration procedure.

19. The method of claim 8 , wherein said inactivating or reducing is performed subsequent to an ultrafiltration or diafiltration procedure.

20. The method of claim 2 , wherein the therapeutic biological product comprises a recombinant protein.

21. The method of claim 2 , wherein said therapeutic biological product comprises a naturally occurring or recombinant immunoglobulin.

22. The method of claim 2 , wherein said therapeutic biological product comprises a naturally occurring or recombinant blood coagulation factor.

23. The method of claim 22 , wherein said blood coagulation factor is selected from the group consisting of:

a) fibrinogen (Factor I);

b) fibrin;

c) prothrombin (Factor II);

d) thrombin;

e) anti-thrombin;

f) Tissue factor Co-factor of VIIa (Factor III);

g) Protein C;

h) Protein S;

i) protein Z;

j) Protein Z-related protease inhibitor;

k) heparin cofactor II;

l) Factor V;

m) Factor-VII;

n) Factor-VIII;

o) Factor-IX;

p) Factor-X;

q) Factor-XI;

r) Factor-XII;

s) Factor-XIII;

t) von Willebrand factor;

u) prekallikrein;

v) high molecular weight kininogen;

w) plasminogen;

x) plasmin;

y) tissue-plasminogen activator;

z) urokinase;

aa) plasminogen activator inhibitor-1; and

ab) plasminogen activator inhibitor-2.

24. The method of claim 2 , wherein said therapeutic biological product is produced by eukaryotic.

25. The method of claim 24 , wherein said eukaryotic cells are mammalian cells.

26. The method of claim 25 , wherein said mammalian cells are Chinese Hamster Ovary (CHO) cells.

27. The method of claim 25 , wherein said mammalian cells are NSO murine myeloma cells.

28. The method of claim 25 , wherein said mammalian cells are human cells.

29. The method of claim 1 , wherein the concentration of arginine is gradually increased using a step-wise or continuous gradient to a final concentration of at least about 0.2 M arginine.

30. The method of claim 29 , wherein said final concentration of arginine is increased by the step-wise or continuous gradient at a rate of about 20% or less per minute.

31. The method of claim 3 , wherein said pH is about 6.5 to 7.5.

32. The method of claim 3 , wherein said pH is about 7.0.

33. The method of claim 1 , wherein said concentration of arginine is about 0.5 M to 3.0 M.

34. The method of claim 4 , wherein said concentration of arginine is about 1.0 M.

35. The method of claim 7 , wherein said glycol compound is propylene glycol.