title: The C1 and C2 domains of blood coagulation factor VIII mediate its endocytosis by dendritic cells.
abstract: The development of inhibitory antibodies to therapeutic factor VIII is the major complication of replacement therapy in patients with hemophilia A. The first step in the initiation of the anti-factor VIII immune response is factor VIII interaction with receptor(s) on antigen-presenting cells, followed by endocytosis and presentation to naïve CD4+T cells. Recent studies indicate a role for the C1 domain in factor VIII uptake. We investigated whether charged residues in the C2 domain participate in immunogenic factor VIII uptake. Co-incubation of factor VIII with BO2C11, a monoclonal C2-specific immunoglobulin G, reduced factor VIII endocytosis by dendritic cells and presentation to CD4+T cells, and diminished factor VIII immunogenicity in factor VIII-deficient mice. The mutation of basic residues within the BO2C11 epitope of C2 replicated reduced in vitro immunogenic uptake, but failed to prevent factor VIII immunogenicity in mice. BO2C11 prevents factor VIII binding to von Willebrand factor, thus potentially biasing factor VIII immunogenicity by perturbing its half-life. Interestingly, a factor VIIIY1680Cmutant, that does not bind von Willebrand factor, demonstrated unaltered endocytosis by dendritic cells as well as immunogenicity in factor VIII-deficient mice. Co-incubation of factor VIIIY1680Cwith BO2C11, however, resulted in decreased factor VIII immunogenicity in vivo In addition, a previously described triple C1 mutant showed decreased uptake in vitro, and reduced immunogenicity in vivo, but only in the absence of endogenous von Willebrand factor. Taken together, the results indicate that residues in the C1 and/or C2 domains of factor VIII are implicated in immunogenic factor VIII uptake, at least in vitro Conversely, in vivo, the binding to endogenous von Willebrand factor masks the reducing effect of mutations in the C domains on factor VIII immunogenicity.
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Bagirath
authors.initials: B
authors.lastname: Gangadharan
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ing
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Delignat
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Peyron
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Teyssandier
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Srinivas V
authors.initials: SV
authors.lastname: Kaveri
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France sebastien.lacroix-desmazes@crc.jussieu.fr.|INSERM, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.|Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, F-75006, Paris, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lacroix-Desmazes
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000070538:C2 Domains; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism*; D004705:Endocytosis / Q000276:immunology*; D005169:Factor VIII / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D055786:Gene Knockout Techniques; D006467:Hemophilia A / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D009154:Mutation; D011485:Protein Binding; D000072417:Protein Domains; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D014841:von Willebrand Factor; D005169:Factor VIII