Immunogenicity of long-lasting recombinant factor VIII products

International audienceReplacement therapy for patients with hemophilia A using plasma-derived or recombinant factor VIII (FVIII) is complicated by the short half-life of the FVIII products and by the occurrence of neutralizing antibodies in a substantial number of patients. In the recent years, enormous efforts have been invested to develop new generations of coagulation factors with extended half-lives. Presumably, the use of long-lasting FVIII products should reduce the frequency of administration to the patients and drastically improve their quality of life. The question of their immunogenicity remains however unanswered as yet. The present review proposes a summary of the different strategies developed to enhance the half-life of FVIII, including fusion of FVIII to the Fc fragment of the human IgG1 or to human serum albumin, or attachment of polyethylene glycol. Based on the available literature, we hypothesize on the potential benefits or risks associated with each of the latter strategies in terms of immunogenicity of the newly derived hemostatic drugs

Correction of bleeding in experimental severe hemophilia A by systemic delivery of factor VIII- encoding mRNA Short title: mRNA-based therapy for hemophilia A Scientific category: Thrombosis and Hemostasis

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The nitrone spin trap 5,5‑dimethyl‑1‑pyrroline N‑oxide binds to toll-like receptor-2-TIR-BB-loop domain and dampens downstream inflammatory signaling

The nitrone spin trap 5,5‑dimethyl‑1‑pyrroline N‑oxide (DMPO) dampens endotoxin-induced and TLR4-driven priming of macrophages, but the mechanism remains unknown. The available information suggests a direct binding of DMPO to the TIR domain, which is shared between TLRs. However, TLR2-TIR domain is the only TLR that have been crystallized. Our in silico data show that DMPO binds to four specific residues in the BB-loop within the TLR2-TIR domain. Our functional analysis using hTLR2.6-expressing HEKs cells showed that DMPO can block zymosan-triggered-TLR2-mediated NF-κB activation. However, DMPO did not affect the overall TLR2-MyD88 protein-protein interaction. DMPO binds to the BB-loop in the TIR-domain and dampens downstream signaling without affecting the overall TIR-MyD88 interaction. These data encourage the use of DMPO-derivatives as potential mechanism-based inhibitors of TLR-triggered inflammation.Fil: Muñoz, Marcos David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Gutierrez, Lucas Joel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Delignat, Sandrine. Université Pierre et Marie Curie; Francia. Centre de Recherche des Cordeliers; FranciaFil: Russick, Jules. Université Pierre et Marie Curie; Francia. Centre de Recherche des Cordeliers; FranciaFil: Gomez-Mejiba, Sandra Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Lacroix Desmazes, Sebastien. Centre de Recherche des Cordeliers; Francia. Université Pierre et Marie Curie; FranciaFil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Ramirez, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin

Catalytic IgG from patients with hemophilia A inactivate therapeutic factor VIII

Factor VIII (FVIII) inhibitors are anti-FVIII IgG that arise in up to 50% of the patients with hemophilia A, upon therapeutic administration of exogenous FVIII. Factor VIII inhibitors neutralize the activity of the administered FVIII by sterically hindering its interaction with molecules of the coagulation cascade, or by forming immune complexes with FVIII and accelerating its clearance from the circulation. We have shown previously that a subset of anti-factor VIII IgG hydrolyzes FVIII. FVIII-hydrolyzing IgG are detected in over 50% of inhibitor-positive patients with severe hemophilia A, and are not found in inhibitornegative patients. Although human proficient catalytic Abs have been described in a number of inflammatory and autoimmune disorders, their pathological relevance remains elusive. We demonstrate here that the kinetics of FVIII degradation by FVIIIhydrolyzing IgG are compatible with a pathogenic role for IgG catalysts. We also report that FVIII-hydrolyzing IgG from each patient exhibit multiple cleavage sites on FVIII and that, while the specificity of cleavage varies from one patient to another, catalytic IgG preferentially hydrolyze peptide bonds containing basic amino acids

Enzymatically oxidized phospholipids restore thrombin generation in coagulation factor deficiencies

Hemostatic defects are treated using coagulation factors; however, clot formation also requires a procoagulant phospholipid (PL) surface. Here, we show that innate immune cell–derived enzymatically oxidized phospholipids (eoxPL) termed hydroxyeicosatetraenoic acid–phospholipids (HETE-PLs) restore hemostasis in human and murine conditions of pathological bleeding. HETE-PLs abolished blood loss in murine hemophilia A and enhanced coagulation in factor VIII- (FVIII-), FIX-, and FX-deficient human plasma . HETE-PLs were decreased in platelets from patients after cardiopulmonary bypass (CPB). To explore molecular mechanisms, the ability of eoxPL to stimulate individual isolated coagulation factor/cofactor complexes was tested in vitro. Extrinsic tenase (FVIIa/tissue factor [TF]), intrinsic tenase (FVIIIa/FIXa), and prothrombinase (FVa/FXa) all were enhanced by both HETE-PEs and HETE-PCs, suggesting a common mechanism involving the fatty acid moiety. In plasma, 9-, 15-, and 12-HETE-PLs were more effective than 5-, 11-, or 8-HETE-PLs, indicating positional isomer specificity. Coagulation was enhanced at lower lipid/factor ratios, consistent with a more concentrated area for protein binding. Surface plasmon resonance confirmed binding of FII and FX to HETE-PEs. HETE-PEs increased membrane curvature and thickness, but not surface charge or homogeneity, possibly suggesting increased accessibility to cations/factors. In summary, innate immune-derived eoxPL enhance calcium-dependent coagulation factor function, and their potential utility in bleeding disorders is proposed

Therapeutic strategies against FVIII immune response in hemophilia A : by modifying FVIII structure, by inhibiting B cells signalisation

L’administration de Facteur VIII thérapeutique (FVIII) chez les patients hémophiles A entraine l’apparition d’anticorps anti-FVIII appelés « inhibiteurs » chez 30% des hémophiles A sévères. Ceci constitue alors une impasse thérapeutique. Si de nombreuses investigations ont permis de caractériser les effecteurs lymphocytaires T et B impliqués dans cette réponse immunitaire, elles n’ont toutefois pas permis de proposer aux patients des stratégies thérapeutiques pour prévenir l’apparition des inhibiteurs du FVIII. La première partie de ma thèse explore la possibilité de prévenir la réponse immunitaire anti-FVIII en inhibant la capture et l’apprêtement antigénique du FVIII par les cellules présentatrices de l’antigène (CPA). Il avait été montré précédemment que les deux structures hautement mannosylées du FVIII, sur les asparagines 239 et 2118, étaient reconnues par le CD206 exprimé par les cellules dendritiques humaines dérivées de monocytes, et que cette voie d’endocytose menait à l’apprêtement antigénique du FVIII. Je me suis donc intéressée à la possibilité de réduire l’immunogénicité du FVIII en éliminant ces deux glycosylations. La seconde partie de ma thèse porte sur la possibilité de prévenir ou d’éradiquer la réponse immunitaire anti-FVIII en inhibant une molécule de la signalisation du récepteur des lymphocytes B (LB) : la tyrosine kinase de Bruton (BTK). La BTK jouant un rôle central dans la signalisation des LB, l’inhibition de celle-ci a montré un intérêt thérapeutique dans le cas de certaines pathologies malignes et auto-immunes. J’ai donc exploré le potentiel thérapeutique d’un inhibiteur de la BTK dans la réponse immunitaire anti-FVIII.Administration of therapeutic factor VIII (FVIII) to hemophilia A patients leads to the development of anti-FVIII antibodies called “inhibitors” in 30% of severe hemophilia A patients. Despite a well characterization of T and B effectors cells involved in this immune response, there is still no therapeutic strategy proposed to the patients to prevent the occurrence of FVIII inhibitors. The first part of my thesis explores the possibility to prevent the anti-FVIII immune response by blocking FVIII capture and processing by antigen presenting cells (APC). It has been previously demonstrated that the two highly mannosylated structures on FVIII, on asparagines 239 and 2118, were recognized by the CD206 expressed on human monocyte-derived dendritic cells. This endocytic pathway led to FVIII processing and presentation to T cells. Therefore, I have investigated the possibility to reduce FVIII immunogenicity by eliminating those two glycosylations. The second part of my thesis focuses on the possibility to prevent or eradicate the anti-FVIII immune response by inhibiting a molecule involved in B cell receptor signaling: the Bruton’s tyrosine kinase (BTK). BTK plays a key role in B cells signaling and inhibition of BTK has shown a great interest in B cell malignancies, but also in some auto-immune diseases. Therefore, I have investigated the therapeutic potential of a new BTK inhibitor against the development of the anti-FVIII immune response

Stratégies thérapeutiques contre la réponse immunitaire anti-Facteur VIII chez l'hémophile A : par modification de la structure du FVIII, par inhibition de la signalisation des lymphocytes B

Administration of therapeutic factor VIII (FVIII) to hemophilia A patients leads to the development of anti-FVIII antibodies called “inhibitors” in 30% of severe hemophilia A patients. Despite a well characterization of T and B effectors cells involved in this immune response, there is still no therapeutic strategy proposed to the patients to prevent the occurrence of FVIII inhibitors. The first part of my thesis explores the possibility to prevent the anti-FVIII immune response by blocking FVIII capture and processing by antigen presenting cells (APC). It has been previously demonstrated that the two highly mannosylated structures on FVIII, on asparagines 239 and 2118, were recognized by the CD206 expressed on human monocyte-derived dendritic cells. This endocytic pathway led to FVIII processing and presentation to T cells. Therefore, I have investigated the possibility to reduce FVIII immunogenicity by eliminating those two glycosylations. The second part of my thesis focuses on the possibility to prevent or eradicate the anti-FVIII immune response by inhibiting a molecule involved in B cell receptor signaling: the Bruton’s tyrosine kinase (BTK). BTK plays a key role in B cells signaling and inhibition of BTK has shown a great interest in B cell malignancies, but also in some auto-immune diseases. Therefore, I have investigated the therapeutic potential of a new BTK inhibitor against the development of the anti-FVIII immune response.L’administration de Facteur VIII thérapeutique (FVIII) chez les patients hémophiles A entraine l’apparition d’anticorps anti-FVIII appelés « inhibiteurs » chez 30% des hémophiles A sévères. Ceci constitue alors une impasse thérapeutique. Si de nombreuses investigations ont permis de caractériser les effecteurs lymphocytaires T et B impliqués dans cette réponse immunitaire, elles n’ont toutefois pas permis de proposer aux patients des stratégies thérapeutiques pour prévenir l’apparition des inhibiteurs du FVIII. La première partie de ma thèse explore la possibilité de prévenir la réponse immunitaire anti-FVIII en inhibant la capture et l’apprêtement antigénique du FVIII par les cellules présentatrices de l’antigène (CPA). Il avait été montré précédemment que les deux structures hautement mannosylées du FVIII, sur les asparagines 239 et 2118, étaient reconnues par le CD206 exprimé par les cellules dendritiques humaines dérivées de monocytes, et que cette voie d’endocytose menait à l’apprêtement antigénique du FVIII. Je me suis donc intéressée à la possibilité de réduire l’immunogénicité du FVIII en éliminant ces deux glycosylations. La seconde partie de ma thèse porte sur la possibilité de prévenir ou d’éradiquer la réponse immunitaire anti-FVIII en inhibant une molécule de la signalisation du récepteur des lymphocytes B (LB) : la tyrosine kinase de Bruton (BTK). La BTK jouant un rôle central dans la signalisation des LB, l’inhibition de celle-ci a montré un intérêt thérapeutique dans le cas de certaines pathologies malignes et auto-immunes. J’ai donc exploré le potentiel thérapeutique d’un inhibiteur de la BTK dans la réponse immunitaire anti-FVIII

Origine et nature de la réponse immunitaire neutralisante contre le facteur VIII thérapeutique

L’utilisation de protéines thérapeutiques se heurte, chez certains patients, à l’apparition d’anticorps neutralisants. C’est le cas, par exemple, du facteur VIII pro-coagulant qui est utilisé pour traiter les patients atteints d’hémophilie A. Plusieurs paramètres, liés à la protéine elle-même, au type de pathologie ou aux patients, conditionnent l’immunogénicité d’une protéine thérapeutique. Les comprendre permettrait d’anticiper ou de prévenir la survenue d’anticorps neutralisants. Nous proposons dans cette revue de montrer que, dans le cas du facteur VIII, la survenue de ces anticorps neutralisants ne résulte pas d’une réponse immunitaire inopinée, mais plutôt de l’incapacité de l’organisme des patients à développer une réponse anti-inflammatoire ou régulatrice

Inhibitor Formation in Congenital Hemophilia A: an Immunological Perspective

International audienceHemophilia A (HA) is an X-linked inherited disorder caused by a defect in the gene encoding coagulation factor VIII (FVIII). The disease is typically divided in three categories of severity based on the circulating levels of pro-coagulant FVIII detected in plasma. HA is "mild" (5-40% of residual FVIII compared with normal plasma), "moderate" (1-5%), or "severe" (<1%). The most efficient strategy to correct or prevent bleeding in the patients relies on the intravenous administration of exogenous therapeutic FVIII that is either plasma derived (pdFVIII) or recombinant (rFVIII). Currently, the most serious complication of FVIII replacement therapy is the development of anti-FVIII antibodies with neutralizing properties that are referred to as "FVIII inhibitors." While anti-drug antibodies typically arise in 1 to 5% of patients, FVIII inhibitors develop in up to 30% of the patients with HA. 1 In addition, the intravenous route of administration is classically considered as non-immunogenic. 2 The elevated rate of development of inhibitory antibodies to FVIII is thus intriguing from an immunological standpoint. Here, we will review the current knowledge on the anti-FVIII immune response with a specific focus on the molecular interactions at play in the recognition of FVIII by the cells of the innate and adaptive immune system and on the intuitively proposed risk factors for FVIII alloimmunization. The review will also propose a short summary of the different immuno-intervention approaches validated in preclinical models of HA to confer tolerance to exogenous FVIII. Dynamics of the anti-FVIII Immune Response The Primary Immune Response to Therapeutic FVIII The development of FVIII inhibitors results from a classical allogenic immune response that is dependent on CD4 T cells. 3 The implication of T cells has been suggested empirically in inhibitor-positive patients who became tolerant to exogenous FVIII following human immunodeficiency virus Keywords ► hemophilia A ► factor VIII ► immunogenicity Abstract The immunogenicity of therapeutic factor VIII (FVIII) in patients with hemophilia A has been puzzling scientific and clinical communities for more than 3 decades. Indeed, the development of inhibitory antibodies to FVIII remains a major clinical challenge and is associated with enormous societal costs. Thus, the reasons for which a presumably innocuous, short-lived, intravenously administered glycoprotein triggers such a dele-terious, long-lasting neutralizing immune response is an enigma. This review does not pretend to bring an answer to this challenging question. It will however summarize the latest findings regarding the molecular interactions at play in the recognition of FVIII by the immune cells, the validity of the proposed risk factors for FVIII alloimmunization, and the different solutions that allow induction of FVIII-specific tolerance in preclinical models of hemophilia A

CD4+CD25+ regulatory T cell-mediated changes in the expression of endocytic receptors and endocytosis process of human dendritic cells

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