Human factor VIII

PCCs contain the vitamin K-dependent factors II, VII, IX, and X. These agents represent another attempt to bypass the factor at which the antibody is directed (see Fig. 64-2). However, PCCs carry the risk of serious thrombotic complications. Porcine factor VIII is most useful when the inhibitor titer is less than 50 BU (see Fig. 64-2 for dose and frequency). Owing to its similarity to human factor VIII, porcine factor VIII participates in the coagulation cascade. However, most inhibitors have very weak neutralizing activity against it. Porcine factor VIII is a third-line agent (only after factor Vila and a PCC have failed) owing to a 15% incidence of cross-reactivity.15... 

Several companies have expressed the cDNA coding for human factor VIII C in a variety of eukaryotic production systems (human VIII C contains 25 potential glycosylation sites). CHO cells and BHK cell lines have been most commonly used, in addition to other cell lines, such as various mouse carcinoma cell lines. The recombinant factor VIII product generally contains only VIII C (i.e. is devoid of vWF). However, both clinical and preclinical studies have shown that administration of this product to patients suffering from haemophilia A is equally as effective as administering blood-derived factor VIII complex. The recombinant VIII C product appears to bind plasma... 

Legaz, M.E., Schmer, G., Counts, R.B., and Davie, E.W. 1973. Isolation and characterization of human factor VIII (antihaemophilic factor). Journal of Biological Chemistry 248, 3946-3955. 

Besman M.J. and Shiba D. (1997), Evaluation of genetic stability of recombinant Human Factor VIII by peptide mapping and on-line mass spectrometric analysis. Pharm. Res. 14(8), 1092-1098. 

Along with the production of insulin, many other medical uses have been achieved for recombinant DNA. This includes the production of erythropoetin, a hormone used to stimulate production of red blood cells in anemic people tissue plasminogen activator, an enzyme that dissolves blood clots in heart attack victims and antihemophilic human factor VIII, used to prevent and control bleeding for hemophiliacs. These three important genetically engineered proteins were all cloned in hamster cell cultures. 

Clinical trials have demonstrated excellent efficacy with recombinant human factor VIII concentrates available as Recombinate and Kogenate. These recombinant factor VIII products are purified from the cell culture of plasmids, not viral DNA-transfected hamster cells and therefore do not express viral sequences. The addition of human serum albumin for stabilization, constitutes the sole possible source for human viral contamination. More recently recombinant factor IX has been genetically engineered by insertion of the human factor IX gene into a Chinese hamster ovary cell line. It has been proved to be safe and effective in the treatment of patients with hemophilia B. 

Antihemophilic factor/von Willebrand factor complex (human)-factor VIII... 

Derrick TS, Kashi RS, Durrani M, Jhingan A, Middaugh CR. Effect of metal cations on the conformation and inactivation of recombinant human factor VIII. J Pharm Sci 2004 93(10) 2549-2557. 

Andrews, J. L., Kadan, M. J., Gorziglia, M. I., Kaleko, M. and Connelly, S. (2001). Generation and characterization of El/E2a/E3/E4-deficient adenoviral vectors encoding human factor VIII. Mol. Ther. 3, 329-336. 

Balague, C., Zhou, J., Dai, Y., Alemany, R., Josephs, S. F., Andreason, G., Hariharan, M., Sethi, E., Prokopenko, E., Jan, H. Y., Lou, Y. C., Hubert-Leslie, D., Ruiz, L. and Zhang, W. W. (2000). Sustained high-level expression of full-length human factor VIII and restoration of clotting activity in hemophilic mice using a minimal adenovirus vector. Blood 95, 820-828. 

Chao, H. and Walsh, C. E. (2001). Induction of tolerance to human factor VIII in mice. Blood 97, 3311-3312. 

Chuah, M. K., Van Damme, A., Zwinnen, H., Goovaerts, I., Vanslembrouck, V., Collen, D. and Vandendriessche, T. (2000). Long-term persistence of human bone marrow stromal cells transduced with factor VUI-retroviral vectors and transient production of therapeutic levels of human factor VIII in nonmyeloablated immunodeficient mice. Hum. Gene Ther. 11, 729-738. 

Connelly, S., Andrews, J. L., Gallo-Penn, A. M., Tagliavacca, L., Kaufman, R. J. and Kaleko, M. (1999). Evaluation of an adenoviral vector encoding full-length human factor VIII in hemophiliac mice. J. Thromb. Haemost. 81, 234-239. 

Dwarki, V. J., Belloni, P., Nijjar, T., Smith, J., Couto, L., Rabier, M., Clift, S., Berns, A. and Cohen, L. K. (1995). Gene therapy for hemophilia A Production of therapeutic levels of human factor VIII in vivo in mice. Proc. Natl. Acad. Sci. USA 92, 1023-1027. 

Garcia-Martin, C., Chuah, M. K., Van Damme, A., Robinson, K. E., Vanzieleghem, B., Saint-Remy, J. M., Gallardo, D., Ofosu, F. A., Vandendriessche, T. and Hortelano, G. (2002). Therapeutic levels of human factor VIII in mice implanted with encapsulated cells Potential for gene therapy of haemophilia A. J. Gene Med. 4, 215-223. 

Gnatenko, D. V., Saenko, E. L., Jesty, J., Cao, L. X., Hearing, P. and Bahou, W. F. (1999). Human factor VIII can be packaged and functionally expressed in an adeno-associated virus background Applicability to haemophilia A gene therapy. Br. J. Haematol. 104, 27-36. 

Park, F., Ohashi, K. and Kay, M. A. (2000). Therapeutic levels of human factor VIII and IX using HIV-1-based lentiviral vectors in mouse liver. Blood 96, 1173-1176. 

Gitschier J, Wood WI, Gopralka TM, Wion KL, Chen EY, Eaton DH, Vehar GA, Capon DJ, Lawn RM. Characterization of the human factor VIII gene. Nature 1984 312 326-330. 

About 40% (938 residues) of the amino-acid sequence of factor V has been established (103). It shows similarities to the amino-acid sequences of human ceruloplasmin and human factor VIII. The partial sequence contains a region that is similar to domains 5 and 6 in ceruloplasmin and A3 in factor VIII. However, it does not have the canonical ligands for type-1 copper or the trinuclear copper site. On the other hand, cysteine residues are present at the homologous position of ceruloplasmin. They form a disulfide bridge in this structure. 

Mordent J, Osaka G, Garcia K, Thomsen K, Licko V, Meng G. Pharmacokinetics and interspecies scaling of recombinant human factor VIII. Toxicol Appl Pharmacol 1996 136 75-8. 

Nesheim, M., Pittman, D. D.,Giles, A Pass, D, N Wang,). H.,Slonosky D., and Kaufman, R. J. fl99l. The effect of plasma von Willebrand factor on the binding of human factor VIII to thrombin-activated human platelets. Biol. Ciicm. 266,17815-17820. 

Hollinger, F.B. Dolana, G. Thomas, W. Gyorkey, F. Reduction in risk of hepatitis transmission by heat treatment of a human factor VIII concentrate. J. Infect. Dis. 

Vehar GA, Keyt B, Eaton D, Rodriguez H, O Brien DP, Rotblat F, et al. Structure of human factor VIII. Nature 1984 312 337-42. 

If the gene therapy causes the production of a protein that was previously absent in the body, then an immune response to the novel protein is likely. Resistance to gene therapy can result from immunization against either the construct or the vector. The former is analogous to the patients who used to become resistant to xenobiotic insulins (see above), and is also seen in the case of human factor VIII in some patients with hemophilia. Escalating doses may be needed to maintain efficacy, or efficacy may be eventually lost. On the other hand, viral vectors are liable to replicate and also to elicit immune responses, just as for any vaccination, creating many of the same problems. 

S. Connelly, J. M. Gardner, A. McClelland, and M. Kaleko, High-level tissue-specific expression of functional human factor VIII in mice. Hum. Gene Ther. 7 183 (1996). 

Fll. Fulcher, C. A., Gardiner, J. ., GrifBn, J. H., and Zimmerman, T. S., Proteolytic inactivation of human Factor VIII procoagulant protein by activated human protein C and its analogy with Factor V. Blood 63, 486-489 (1984). 

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