[HTML][HTML] The leak stops here: platelets as delivery vehicles for coagulation factors

KA High - The Journal of clinical investigation, 2006 - Am Soc Clin Investig
KA High
The Journal of clinical investigation, 2006Am Soc Clin Investig
Inhibitory immune response to exogenously infused factor VIII (FVIII) is a major complication
in the treatment of hemophilia A. Generation of such inhibitors has the potential to disrupt
gene therapy for hemophilia A. We explore what we believe to be a novel approach to
overcome this shortcoming. Human B-domain–deleted FVIII (hBDDFVIII) was expressed
under the control of the platelet-specific αIIb promoter in platelets of hemophilic (FVIIInull)
mice to create 2bF8trans mice. The FVIII transgene product was stored in platelets and …
Abstract
Inhibitory immune response to exogenously infused factor VIII (FVIII) is a major complication in the treatment of hemophilia A. Generation of such inhibitors has the potential to disrupt gene therapy for hemophilia A. We explore what we believe to be a novel approach to overcome this shortcoming. Human B-domain–deleted FVIII (hBDDFVIII) was expressed under the control of the platelet-specific αIIb promoter in platelets of hemophilic (FVIIInull) mice to create 2bF8trans mice. The FVIII transgene product was stored in platelets and released at the site of platelet activation. In spite of the lack of FVIII in the plasma of 2bF8trans mice, the bleeding phenotype of FVIIInull mice was corrected. More importantly, the bleeding phenotype was corrected in the presence of high inhibitory antibody titers introduced into the mice by infusion or by spleen cell transfer from recombinant hBDDFVIII–immunized mice. Our results demonstrate that this approach to the targeted expression of FVIII in platelets has the potential to correct hemophilia A, even in the presence of inhibitory immune responses to infused FVIII.
The Journal of Clinical Investigation