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Neutralisation of factor VIII inhibitors by anti-idiotypes isolated from phage-displayed libraries.
- Source :
-
Thrombosis and haemostasis [Thromb Haemost] 2016 Jul 04; Vol. 116 (1), pp. 32-41. Date of Electronic Publication: 2016 Mar 24. - Publication Year :
- 2016
-
Abstract
- Following replacement therapy with coagulation factor VIII (FVIII), up to 30 % of haemophilia A patients develop FVIII-specific inhibitory antibodies (FVIII inhibitors). Immune tolerance induction (ITI) is not always successful, resulting in a need for alternative treatments for FVIII inhibitor-positive patients. As tolerance induction in the course of ITI appears to involve the formation of anti-idiotypes specific for anti-FVIII antibodies, such anti-idiotypes might be used to restore haemostasis in haemophilia A patients with FVIII inhibitors. We isolated anti-idiotypic antibody fragments (scFvs) binding to murine FVIII inhibitors 2-76 and 2-77 from phage-displayed libraries. FVIII inhibitor/anti-idiotype interactions were very specific as no cross-reactivity with other FVIII inhibitors or isotype controls was observed. ScFvs blocked binding of FVIII inhibitors to FVIII and neutralised their cognate inhibitors in vitro and a monoclonal mouse model. In addition, scFv JkH5 specific for FVIII inhibitor 2-76 stained 2-76-producing hybridoma cells. JkH5 residues R52 and Y226, located in complementary determining regions, were identified as crucial for the JkH5/2-76 interaction using JkH5 alanine mutants. SPR spectroscopy revealed that JkH5 interacts with FVIII inhibitor 2-76 with nanomolar affinity. Thus, FVIII inhibitor-specific, high-affinity anti-idiotypes can be isolated from phage-displayed libraries and neutralise their respective inhibitors. Furthermore, we show that anti-idiotypic scFvs might be utilised to specifically target inhibitor-specific B cells. Hence, a pool of anti-idiotypes could enable the reestablishment of haemostasis in the presence of FVIII inhibitors in patients or even allow the depletion of inhibitors by targeting inhibitor-specific B cell populations.
- Subjects :
- Animals
Antibodies, Monoclonal, Murine-Derived immunology
Antibodies, Monoclonal, Murine-Derived therapeutic use
Antibodies, Neutralizing immunology
Antibodies, Neutralizing therapeutic use
Antibody Specificity
Cross Reactions
Disease Models, Animal
Epitope Mapping
Factor VIII genetics
Hemophilia A genetics
Humans
Hybridomas immunology
Immune Tolerance
In Vitro Techniques
Kinetics
Male
Mice
Mice, Knockout
Peptide Library
Single-Chain Antibodies genetics
Single-Chain Antibodies immunology
Single-Chain Antibodies therapeutic use
Antibodies, Anti-Idiotypic immunology
Antibodies, Anti-Idiotypic therapeutic use
Factor VIII antagonists & inhibitors
Factor VIII immunology
Hemophilia A immunology
Hemophilia A therapy
Subjects
Details
- Language :
- English
- ISSN :
- 2567-689X
- Volume :
- 116
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Thrombosis and haemostasis
- Publication Type :
- Academic Journal
- Accession number :
- 27009573
- Full Text :
- https://doi.org/10.1160/TH15-12-0925