In:
Blood, American Society of Hematology, Vol. 97, No. 4 ( 2001-02-15), p. 966-972
Abstract:
A well-known complication of factor VIII replacement therapy in patients with hemophilia A is the development of inhibitory antibodies. Several studies have demonstrated the presence of a binding site for factor VIII inhibitors in the A3 domain. Six different human monoclonal single-chain variable domain antibody fragments (scFv) directed toward the A3-C1 domains of factor VIII have been isolated, using phage display technology. Sequence analysis revealed that the VH domains of 2 scFv were encoded by germline gene segments from the VH1 gene family and 4 by germline gene segments belonging to the VH3 gene family. Epitope mapping of the scFv was performed, using a series of hybrid factor VIII/factor V light chain fragments. This analysis revealed that 5 of 6 scFv were directed against a region encompassing amino acid sequence Q1778-D1840 in the A3 domain, a previously identified binding site for factor VIII inhibitors. Only 2 of 5 scFv directed against amino acid sequence Q1778-D1840 inhibited the procoagulant activity of factor VIII. Our results define the properties of human antibodies directed against region Q1778-D1840 in the A3 domain. Binding of one, noninhibitory scFv was independent of the region Q1778-D1840, suggesting the presence of an additional binding site for anti–factor VIII antibodies in the A3-C1 domains of factor VIII.
Type of Medium:
Online Resource
ISSN:
1528-0020
,
0006-4971
DOI:
10.1182/blood.V97.4.966
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2001
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
