Human Factor IX Corrects the Bleeding Diathesis of Mice With Hemophilia B

• Published in: Blood Vol. 91; no. 3; pp. 784 - 790
• Main Authors: Kung, Szu-Hao, Nathan Hagstrom, J., Cass, Darrell, Jen Tai, Shing, Lin, Hui-Feng, Stafford, Darrel W., High, Katherine A.
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 01.02.1998; The Americain Society of Hematology
• Subjects: Adenoviridae - genetics; Animals; Antibodies - blood; Biological and medical sciences; Bleeding Time; Blood Coagulation; Factor IX - genetics; Factor IX - immunology; Factor IX - therapeutic use; Female; Gene Expression; Gene Transfer Techniques; Genetic Vectors; Hematologic and hematopoietic diseases; Hemophilia B - blood; Hemophilia B - complications; Hemophilia B - drug therapy; Hemorrhage - prevention & control; Humans; Liver - metabolism; Male; Medical sciences; Mice; Mice, Inbred C57BL; Partial Thromboplastin Time; Platelet diseases and coagulopathies; Human origin; Vertebrata; Mammalia; Factor IX; Treatment; Mouse; Animal; Rodentia; Hemophilia B; Hemopathy; Coagulopathy; Genetic disease
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V91.3.784

Mice with hemophilia B have been engineered using gene targeting techniques. These animals exhibit severe factor IX deficiency and a clinical phenotype that mirrors the human disease. We have bred the founder animals onto two different strains of mice, C57B1/6 and CD-1, and have sought to determine whether adenoviral vectors expressing human factor IX could correct the bleeding diathesis of mice with hemophilia B. Initial experiments showed that purified plasma-derived human factor IX added to murine factor IX–deficient plasma resulted in complete correction of the activated partial thromboplastin time (aPTT), and that injection of 1011 particles of an adenoviral vector expressing human factor IX resulted in normalization of a modified aPTT in mouse plasma. As an additional method of assessing the function of human factor IX in the murine coagulation system, bleeding times were performed in normal, hemophilic, and adenoviral-treated hemophilic mice. By two different bleeding-time techniques, the treated hemophilic mice gave values identical to normal littermate controls, whereas the untreated hemophilic mice exhibited heavy blood loss and prolonged bleeding. There was a marked difference in antibody formation in the two strains of mice; 100% of the hemophilic CD-1 mice formed antibodies to human factor IX, but none of the C57B1/6 mice did. These data suggest that the C57B1/6 hemophilic mice will be more useful for gene transfer studies, while the CD-1 hemophilic mice may be of greater utility in studying the development of inhibitors.