VWF protects FVIII from endocytosis by dendritic cells and subsequent presentation to immune effectors

S Dasgupta, Y Repessé, J Bayry, AM Navarrete… - Blood, 2007 - ashpublications.org
S Dasgupta, Y Repessé, J Bayry, AM Navarrete, B Wootla, S Delignat, T Irinopoulou…
Blood, 2007ashpublications.org
Von Willebrand factor (VWF) is a chaperone molecule for procoagulant factor VIII (FVIII). Its
role in the reduction of the immunogenicity of therapeutic FVIII in patients with hemophilia A
has been evoked but lacks clear cellular and molecular rationale. Here, we demonstrate that
VWF protects FVIII from being endocytosed by human dendritic cells (DCs) and
subsequently presented to FVIII-specific T cells. The immunoprotective effect of VWF
requires a physical interaction with FVIII because the endocytosis of FVIII was significantly …
Abstract
Von Willebrand factor (VWF) is a chaperone molecule for procoagulant factor VIII (FVIII). Its role in the reduction of the immunogenicity of therapeutic FVIII in patients with hemophilia A has been evoked but lacks clear cellular and molecular rationale. Here, we demonstrate that VWF protects FVIII from being endocytosed by human dendritic cells (DCs) and subsequently presented to FVIII-specific T cells. The immunoprotective effect of VWF requires a physical interaction with FVIII because the endocytosis of FVIII was significantly restored on hindering the formation of the VWF-FVIII complex. Interestingly, VWF had no direct inhibitory effect either on the ability of DCs to present antigenic peptides or on the activation potency of CD4+ T cells. We thus propose that VWF may reduce the immunogenicity of FVIII by preventing, upstream from the activation of immune effectors, the entry of FVIII in professional antigen-presenting cells.
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