1
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Chen Z, Herzog RW, Kaufman RJ. Cellular stress and coagulation factor production: when more is not necessarily better. J Thromb Haemost 2023; 21:3329-3341. [PMID: 37839613 PMCID: PMC10760459 DOI: 10.1016/j.jtha.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/17/2023]
Abstract
Remarkably, it has been 40 years since the isolation of the 2 genes involved in hemophilia A (HA) and hemophilia B (HB), encoding clotting factor (F) VIII (FVIII) and FIX, respectively. Over the years, these advances led to the development of purified recombinant protein factors that are free of contaminating viruses from human pooled plasma for hemophilia treatments, reducing the morbidity and mortality previously associated with human plasma-derived clotting factors. These discoveries also paved the way for modified factors that have increased plasma half-lives. Importantly, more recent advances have led to the development and Food and Drug Administration approval of a hepatocyte-targeted, adeno-associated viral vector-mediated gene transfer approach for HA and HB. However, major concerns regarding the durability and safety of HA gene therapy remain to be resolved. Compared with FIX, FVIII is a much larger protein that is prone to misfolding and aggregation in the endoplasmic reticulum and is poorly secreted by the mammalian cells. Due to the constraint of the packaging capacity of adeno-associated viral vector, B-domain deleted FVIII rather than the full-length protein is used for HA gene therapy. Like full-length FVIII, B-domain deleted FVIII misfolds and is inefficiently secreted. Its expression in hepatocytes activates the cellular unfolded protein response, which is deleterious for hepatocyte function and survival and has the potential to drive hepatocellular carcinoma. This review is focused on our current understanding of factors limiting FVIII secretion and the potential pathophysiological consequences upon expression in hepatocytes.
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Affiliation(s)
- Zhouji Chen
- Degenerative Diseases Program, Center for Genetic Diseases and Aging Research, SBP Medical Discovery Institute, California, USA
| | - Roland W Herzog
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, Indiana, USA
| | - Randal J Kaufman
- Degenerative Diseases Program, Center for Genetic Diseases and Aging Research, SBP Medical Discovery Institute, California, USA.
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2
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Sarafanov AG. Plasma Clearance of Coagulation Factor VIII and Extension of Its Half-Life for the Therapy of Hemophilia A: A Critical Review of the Current State of Research and Practice. Int J Mol Sci 2023; 24:ijms24108584. [PMID: 37239930 DOI: 10.3390/ijms24108584] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Factor VIII (FVIII) is an important component of blood coagulation as its congenital deficiency results in life-threatening bleeding. Current prophylactic therapy of the disease (hemophilia A) is based on 3-4 intravenous infusions of therapeutic FVIII per week. This poses a burden on patients, demanding reduction of infusion frequency by using FVIII with extended plasma half-life (EHL). Development of these products requires understanding FVIII plasma clearance mechanisms. This paper overviews (i) an up-to-date state of the research in this field and (ii) current EHL FVIII products, including recently approved efanesoctocog alfa, for which the plasma half-life exceeds a biochemical barrier posed by von Willebrand factor, complexed with FVIII in plasma, which results in ~1 per week infusion frequency. We focus on the EHL FVIII products' structure and function, in particular related to the known discrepancy in results of one-stage clotting (OC) and chromogenic substrate (CS) assays used to assign the products' potency, dosing, and for clinical monitoring in plasma. We suggest a possible root cause of these assays' discrepancy that is also pertinent to EHL factor IX variants used to treat hemophilia B. Finally, we discuss approaches in designing future EHL FVIII variants, including those to be used for hemophilia A gene therapy.
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Affiliation(s)
- Andrey G Sarafanov
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA
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3
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Yoshimura T, Horiuchi K, Shimonishi N, Ogiwara K, Horie K, Shima M, Nogami K. Modified expi293 cell culture system using piggyBac transposon enables efficient production of human FVIII. Int J Hematol 2023; 117:56-67. [PMID: 36229740 DOI: 10.1007/s12185-022-03468-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 10/04/2022] [Accepted: 10/06/2022] [Indexed: 01/20/2023]
Abstract
Human blood coagulation factor VIII (hFVIII) is used in hemostatic and prophylactic treatment of patients with hemophilia A. Biotechnological innovations have enabled purification of the culture medium of rodent or human cells harboring the hFVIII expression cassette. However, cell lines express hFVIII protein derived from an exogenous expression vector at a lower level than most other proteins. Here, we describe hFVIII production using piggyBac transposon and the human-derived expi293F cell line. Use of a drug selection protocol, rather than transient expression protocol, allowed cells harboring hFVIII expression cassettes to efficiently produce hFVIII. In heterogeneous drug-selected cells, the production level was maintained even after multiple passages. The specific activity of the produced hFVIII was comparable to that of the commercial product and hFVIII derived from baby hamster kidney cells. We also applied codon optimization to the hFVIII open reading frame sequences in the transgene, which increased production of full-length hFVIII, but decreased production of B-domain-deleted human FVIII (BDD-hFVIII). Low transcriptional abundance of the hF8 transgene was observed in cells harboring codon-optimized BDD-hFVIII expression cassettes, which might partially contribute to decreased hFVIII production. The mechanism underlying these distinct outcomes may offer clues to highly efficient hFVIII protein production.
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Affiliation(s)
- Takuji Yoshimura
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan.
| | - Kaoru Horiuchi
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan
| | - Naruto Shimonishi
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan
| | - Kenichi Ogiwara
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan
| | - Kyoji Horie
- Department of Physiology II, Nara Medical University, Kashihara, Nara, Japan
| | - Midori Shima
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan.,The Center of Thrombosis and Hemostasis, Nara Medical University, Kashihara, Nara, Japan
| | - Keiji Nogami
- Department of Pediatrics, Nara Medical University, 840 Shijo-Cho, Kashihara, Nara, 634-8522, Japan.
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4
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Mao J, Wang Y, Zhang W, Shen Y, Zhang G, Xi W, Wang Q, Ruan Z, Wang J, Xi X. Long-term correction of hemorrhagic diathesis in hemophilia A mice by an AAV-delivered hybrid FVIII composed of the human heavy chain and the rat light chain. Front Med 2022; 16:584-595. [PMID: 35038106 DOI: 10.1007/s11684-021-0844-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/29/2020] [Indexed: 12/01/2022]
Abstract
Conventional therapies for hemophilia A (HA) are prophylactic or on-demand intravenous FVIII infusions. However, they are expensive and inconvenient to perform. Thus, better strategies for HA treatment must be developed. In this study, a recombinant FVIII cDNA encoding a human/rat hybrid FVIII with an enhanced procoagulant potential for adeno-associated virus (AAV)-delivered gene therapy was developed. Plasmids containing human FVIII heavy chain (hHC), human light chain (hLC), and rat light chain (rLC) were transfected into cells and hydrodynamically injected into HA mice. Purified AAV viruses were intravenously injected into HA mice at two doses. Results showed that the hHC + rLC protein had a higher activity than the hHC + hLC protein at comparable expression levels. The specific activity of hHC + rLC was about 4- to 8-fold higher than that of their counterparts. Hydrodynamic injection experiments obtained consistent results. Notably, the HA mice undergoing the AAV-delivered hHC + rLC treatment exhibited a visibly higher activity than those treated with hHC + hLC, and the therapeutic effects lasted for up to 40 weeks. In conclusion, the application of the hybrid FVIII (hHC + rLC) via an AAV-delivered gene therapy substantially improved the hemorrhagic diathesis of the HA mice. These data might be of help to the development of optimized FVIII expression cassette for HA gene therapy.
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Affiliation(s)
- Jianhua Mao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Yun Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.,Shanghai Institute of Hematology, State Key Laboratory for Medical Genomics and Department of Hematology, Collaborative Innovation Center of Systems Biomedicine, Pôle Sino-Français des Sciences du Vivant et Genomique, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Wei Zhang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yan Shen
- Research Center for Experimental Medicine, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Guowei Zhang
- The School of Medicine, Hangzhou Normal University, Hangzhou, 310036, China
| | - Wenda Xi
- Shanghai Institute of Hypertension, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Qiang Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zheng Ruan
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jin Wang
- Shanghai Institute of Hematology, State Key Laboratory for Medical Genomics and Department of Hematology, Collaborative Innovation Center of Systems Biomedicine, Pôle Sino-Français des Sciences du Vivant et Genomique, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiaodong Xi
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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5
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Thrombin generation test based on a 96-channel pipettor for evaluation of FXIa procoagulant activity in pharmaceuticals. Nat Protoc 2021; 16:3981-4003. [PMID: 34215864 DOI: 10.1038/s41596-021-00568-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
Thrombin generation (TG) assays are used widely to investigate both diseases and drugs that impact thrombosis and bleeding. TG assays were also instrumental in the identification of thrombogenic impurities in immune globulin products, which were associated with thrombotic adverse events in patients. TG assays are therefore now used by quality control laboratories of plasma derivative drug manufacturers and regulatory agencies responsible for the safety testing and release of immune globulin products. In this protocol, we describe a robust and sensitive version of the TG assay for quantitative measurement of thrombogenic activity in immune globulin products. Compared with the version of the assay commonly used in clinical laboratories that compares individual patient plasma samples with normal donor samples, our TG assay is suitable for quick (170-260 min) semiautomated analysis of multiple drug samples against the World Health Organization international standard for factor XIa. Commercially available reagents can be used for the assay, and it does not require specialized equipment. The protocol can be easily adapted for the measurement of the procoagulant activity of other biopharmaceuticals, e.g., coagulation factors.
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6
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Lisowski L, Staber JM, Wright JF, Valentino LA. The intersection of vector biology, gene therapy, and hemophilia. Res Pract Thromb Haemost 2021; 5:e12586. [PMID: 34485808 PMCID: PMC8410952 DOI: 10.1002/rth2.12586] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/01/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
Gene therapy is at the forefront of the drive to bring the potential of cure to patients with genetic diseases. Multiple mechanisms of effective and efficient gene therapy delivery (eg, lentiviral, adeno-associated) for transgene expression as well as gene editing have been explored to improve vector and construct attributes and achieve therapeutic success. Recent clinical research has focused on recombinant adeno-associated viral (rAAV) vectors as a preferred method owing to their naturally occurring vector biology characteristics, such as serotypes with specific tissue tropisms, facilitated in vivo delivery, and stable physicochemical properties. For those living with hereditary diseases like hemophilia, this potential curative approach is balanced against the need to provide safe, predictable, effective, and durable factor expression. While in vivo studies of rAAV gene therapy have demonstrated amelioration of the bleeding phenotype in adults, long-term safety and effectiveness remain to be established. This review discusses vector biology in the context of rAAV-based liver-directed gene therapy for hemophilia and provides an overview of the types of viral vectors and vector components that are under investigation, as well as an assessment of the challenges associated with gene therapy delivery and durability of expression.
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Affiliation(s)
- Leszek Lisowski
- Translational Vectorology Research UnitFaculty of Medicine and HealthChildren's Medical Research InstituteThe University of SydneyWestmeadAustralia
- Laboratory of Molecular Oncology and Innovative TherapiesMilitary Institute of MedicineWarsawPoland
| | - Janice M. Staber
- Stead Family Department of PediatricsUniversity of IowaIowa CityIAUSA
- Carver College of MedicineUniversity of IowaIowa CityIAUSA
| | - J. Fraser Wright
- Department of PediatricsDivision of Hematology, OncologyStem Cell Transplantation and Regenerative MedicineCenter for Definitive and Curative MedicineStanford University School of MedicineStanfordCAUSA
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7
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Chun H, Pettersson JR, Shestopal SA, Wu WW, Marakasova ES, Olivares P, Surov SS, Ovanesov MV, Shen RF, Sarafanov AG. Characterization of protein unable to bind von Willebrand factor in recombinant factor VIII products. J Thromb Haemost 2021; 19:954-966. [PMID: 33527662 DOI: 10.1111/jth.15257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Therapeutic products with coagulation factor VIII (FVIII) have a wide range of specific activities, implying presence of protein with altered structure. Previous studies showed that recombinant FVIII products (rFVIII) contain a fraction (FVIIIFT ) unable to bind von Willebrand factor (VWF) and reported to lack activity. Because of loss of function(s), FVIIIFT can be defined as a product-related impurity, whose properties and levels in rFVIII products should be investigated. OBJECTIVE To isolate and characterize the FVIIIFT fraction in rFVIII products. METHODS Protein fractions unable (FVIIIFT ) and able (FVIIIEL ) to bind VWF were isolated from rFVIII products using immobilized VWF affinity chromatography (IVAC) and characterized by gel electrophoresis, immunoblotting, FVIII activity test, surface plasmon resonance, mass spectrometry, and for plasma clearance in mice. RESULTS AND CONCLUSIONS A robust IVAC methodology was developed and applied for analysis of 10 rFVIII products marketed in the United States. FVIIIFT was found at various contents (0.4%-21.5%) in all products. Compared with FVIIIEL , FVIIIFT had similar patterns of polypeptide bands by gel electrophoresis, but lower functional activity. In several representative products, FVIIIFT was found to have reduced sulfation at Tyr1680, important for VWF binding, decreased interaction with a low-density lipoprotein receptor-related protein 1 fragment, and faster plasma clearance in mice. These findings provide basic characterization of FVIIIFT and demonstrate a potential for IVAC to control this impurity in rFVIII products to improve their efficacy in therapy of hemophilia A.
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Affiliation(s)
- Haarin Chun
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - John R Pettersson
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Svetlana A Shestopal
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Wells W Wu
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Ekaterina S Marakasova
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Philip Olivares
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Stepan S Surov
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Mikhail V Ovanesov
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Rong-Fong Shen
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Andrey G Sarafanov
- Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
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8
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Peyvandi F, Miri S, Garagiola I. Immune Responses to Plasma-Derived Versus Recombinant FVIII Products. Front Immunol 2021; 11:591878. [PMID: 33552050 PMCID: PMC7862552 DOI: 10.3389/fimmu.2020.591878] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/04/2020] [Indexed: 11/27/2022] Open
Abstract
The most severe side effect of hemophilia treatment is the inhibitor development occurring in 30% of patients, during the earliest stages of treatment with factor (F)VIII concentrates. These catastrophic immune responses rapidly inactivate the infused FVIII, rendering the treatment ineffective. This complication is associated with a substantial morbidity and mortality. The risk factors involved in the onset of the inhibitors are both genetic and environmental. The source of FVIII products, i.e. plasma-derived or recombinant FVIII products, is considered one of the most relevant factors for inhibitor development. Numerous studies in the literature report conflicting data on the different immunogenicity of the products. The SIPPET randomized trial showed an increased in the inhibitor rate in patients using recombinant FVIII products than those receiving plasma-derived products in the first exposure days. The SIPPET randomized trial showed an increase in the inhibitor rate in patients using recombinant FVIII products compared to those treated with plasma-derived products in the first days of exposure. The potential increase in the immunogenicity of recombinant products can be attributed to several factors such as: the different post-translational modification in different cell lines, the presence of protein aggregates, and the role played by the chaperon protein of FVIII, the von Willebrand factor, which modulates the uptake of FVIII by antigen presenting cells (APCs). Furthermore, the presence of non-neutralizing antibodies against FVIII has shown to be in increased inhibitor development as demonstrated in a sub-analysis of the SIPPET study. In addition, the presence of the specific subclasses of the immunoglobulins may also be an important biomarker to indicate whether the inhibitor will evolve into a persistent neutralizing antibody or a transient one that would disappear without any specific treatment. Recently, the availability of novel non-replacement therapies as well as emicizumab, administered by weekly subcutaneous infusion, have significantly changed the quality of life of patients with inhibitors showing a considerable reduction of the annual bleeding rate and in most patients the absence of bleeding. Although, these novel drugs improve patients' quality of life, they do not abolish the need to infuse FVIII during acute bleeding or surgery. Therefore, the issue of immunogenicity against FVIII still remains an important side effect of hemophilia treatment.
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Affiliation(s)
- Flora Peyvandi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Fondazione Luigi Villa, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Syna Miri
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy
| | - Isabella Garagiola
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Fondazione Luigi Villa, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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9
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Cao W, Dong B, Horling F, Firrman JA, Lengler J, Klugmann M, de la Rosa M, Wu W, Wang Q, Wei H, Moore AR, Roberts SA, Booth CJ, Hoellriegl W, Li D, Konkle B, Miao C, Reipert BM, Scheiflinger F, Rottensteiner H, Xiao W. Minimal Essential Human Factor VIII Alterations Enhance Secretion and Gene Therapy Efficiency. Mol Ther Methods Clin Dev 2020; 19:486-495. [PMID: 33313336 PMCID: PMC7708868 DOI: 10.1016/j.omtm.2020.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/19/2020] [Indexed: 12/18/2022]
Abstract
One important limitation for achieving therapeutic expression of human factor VIII (FVIII) in hemophilia A gene therapy is inefficient secretion of the FVIII protein. Substitution of five amino acids in the A1 domain of human FVIII with the corresponding porcine FVIII residues generated a secretion-enhanced human FVIII variant termed B-domain-deleted (BDD)-FVIII-X5 that resulted in 8-fold higher FVIII activity levels in the supernatant of an in vitro cell-based assay system than seen with unmodified human BDD-FVIII. Analysis of purified recombinant BDD-FVIII-X5 and BDD-FVIII revealed similar specific activities for both proteins, indicating that the effect of the X5 alteration is confined to increased FVIII secretion. Intravenous delivery in FVIII-deficient mice of liver-targeted adeno-associated virus (AAV) vectors designed to express BDD-FVIII-X5 or BDD-FVIII achieved substantially higher plasma FVIII activity levels for BDD-FVIII-X5, even when highly efficient codon-optimized F8 nucleotide sequences were employed. A comprehensive immunogenicity assessment using in vitro stimulation assays and various in vivo preclinical models of hemophilia A demonstrated that the BDD-FVIII-X5 variant does not exhibit an increased immunogenicity risk compared to BDD-FVIII. In conclusion, BDD-FVIII-X5 is an effective FVIII variant molecule that can be further developed for use in gene- and protein-based therapeutics for patients with hemophilia A.
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Affiliation(s)
- Wenjing Cao
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Biao Dong
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Franziska Horling
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Jenni A. Firrman
- Dairy and Functional Foods Research Unit, ARS, USDA, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
| | - Johannes Lengler
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Matthias Klugmann
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Maurus de la Rosa
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Wenman Wu
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Qizhao Wang
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Hongying Wei
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Andrea R. Moore
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Sean A. Roberts
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Carmen J. Booth
- Department of Comparative Medicine, Yale University School of Medicine, 310 Cedar St., BML 330, New Haven, CT 06510, USA
| | - Werner Hoellriegl
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Dong Li
- Sol Sherry Thrombosis Research Center, Temple University Medical School, 3400 North Broad Street, Philadelphia, PA, 19140, USA
| | - Barbara Konkle
- Seattle Children’s Research Institute, University of Washington, 1900 9 Ave, Seattle, WA 98195, USA
| | - Carol Miao
- Department of Medicine/Hematology, University of Washington, 1900 9 Ave, Seattle, WA 98195, USA
| | - Birgit M. Reipert
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Friedrich Scheiflinger
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Hanspeter Rottensteiner
- Drug Discovery Austria, Baxalta Innovations GmbH (now part of Takeda), Donau-City Str. 7, Vienna 1220, Austria
| | - Weidong Xiao
- Herman B Wells Center for Pediatric Research, Indiana University, Indianapolis, IN 46202, USA
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10
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Zhou M, Hu Z, Zhang C, Wu L, Li Z, Liang D. Gene Therapy for Hemophilia A: Where We Stand. Curr Gene Ther 2020; 20:142-151. [PMID: 32767930 DOI: 10.2174/1566523220666200806110849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/25/2020] [Accepted: 07/13/2020] [Indexed: 01/19/2023]
Abstract
Hemophilia A (HA) is a hereditary hemorrhagic disease caused by a deficiency of coagulation factor VIII (FVIII) in blood plasma. Patients with HA usually suffer from spontaneous and recurrent bleeding in joints and muscles, or even intracerebral hemorrhage, which might lead to disability or death. Although the disease is currently manageable via delivery of plasma-derived or recombinant FVIII, this approach is costly, and neutralizing antibodies may be generated in a large portion of patients, which render the regimens ineffective and inaccessible. Given the monogenic nature of HA and that a slight increase in FVIII can remarkably alleviate the phenotypes, HA has been considered to be a suitable target disease for gene therapy. Consequently, the introduction of a functional F8 gene copy into the appropriate target cells via viral or nonviral delivery vectors, including gene correction through genome editing approaches, could ultimately provide an effective therapeutic method for HA patients. In this review, we discuss the recent progress of gene therapy for HA with viral and nonviral delivery vectors, including piggyBac, lentiviral and adeno-associated viral vectors, as well as new raising issues involving liver toxicity, pre-existing neutralizing antibodies of viral approach, and the selection of the target cell type for nonviral delivery.
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Affiliation(s)
- Miaojin Zhou
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Zhiqing Hu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Chunhua Zhang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Lingqian Wu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Zhuo Li
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
| | - Desheng Liang
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan 410078, China
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11
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Firrman J, Wang Q, Wu W, Dong B, Cao W, Moore AR, Roberts S, Konkle BA, Miao C, Liu L, Li D, Xiao W. Identification of Key Coagulation Activity Determining Elements in Canine Factor VIII. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:328-336. [PMID: 32071925 PMCID: PMC7013134 DOI: 10.1016/j.omtm.2019.12.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/24/2019] [Indexed: 11/29/2022]
Abstract
It is well known that canine factor VIII (cFVIII) has a higher specific activity than does human FVIII (hFVIII), and it has been previously demonstrated that cFVIII light chain is able to enhance hFVIII activity. The goal of this study was to first determine which amino acids in cFVIII light chain were responsible for enhancing hFVIII activity, and second to use these amino acids to develop a hFVIII variant with enhanced functional activity. We systemically screened segments of cFVIII light chain by testing an array of human-canine light chain hybrids and found that canine amino acids 1857-2147 were key to this enhancement. Each canine amino acid within this span was screened individually using a negative selection method, which led to the identification of 12 aa (JF12) in the FVIII light chain that could enhance activity. Substitution of the corresponding 12 aa into hFVIII (hFVIIIJF12BDD) elevated the specific activity profile in vitro. Furthermore, hFVIIIJF12BDD expressed an in vivo-displayed increased coagulation activity compared to wild-type, while maintaining normal secretion efficiency. In conclusion, we identified the amino acids in cFVIII that are the key determinants for higher specific activity and may be the basis for future development of therapeutic treatments for hemophilia A.
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Affiliation(s)
- Jenni Firrman
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA, USA.,Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA
| | - Qizhao Wang
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Wenman Wu
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Biao Dong
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Wenjing Cao
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Andrea Rossi Moore
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Sean Roberts
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Barbara A Konkle
- Bloodworks Northwest, Seattle, WA, USA.,Department of Medicine, University of Washington, Seattle, WA, USA
| | - Carol Miao
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - LinShu Liu
- Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA
| | - Dong Li
- Shanghai Tongji Hospital, Tongji University, Shanghai, P.R. China
| | - Weidong Xiao
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA, USA.,Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA.,Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA, USA
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12
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Jun Z, Ming-Ming L, Qian-Qing Z, Yun-Hong W, Chong-Yang Z, Xin L. Functional identification of factor VIII B domain regions in hepatocyte cells. Biochem Biophys Res Commun 2020; 526:633-640. [PMID: 32248973 DOI: 10.1016/j.bbrc.2020.03.132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 03/23/2020] [Indexed: 11/15/2022]
Abstract
Factor VIII (FVIII) functions as a cofactor within the intrinsic pathway of blood coagulation in process of FX activation by FIXa, for which deficiency results in the bleeding disorder hemophilia A. The gene of FVIII contains 26 exons that code for a 19 amino acid signal peptide and a 2332 amino acid polypeptide with a domain structure designated A1-A2-B-A3-C1-C2, of which the A domains are homologous with each other, as are the C domains. It has been well-documented that both the domains are the necessary elements for FVIII activities. The B domain is highly glycosylated and has a variable sequence, even among FVIIIs from different species. The B domain plays versatile roles in FVIII lifespan except for coagulation activity, but the functional characteristics of its specific regions remain still obscure. A series of recombinant FVIIIs (rFVIIIs) with B domain truncated were constructed and transiently expressed in hepatocyte cells. Media and cell lysates were collected after 72 h for the analyses of FVIII biosynthesis, secretion, activity and stability in ex vivo plasma relative to the full length wild-type FVIII. Unexpectedly, various regions in B domain exhibited different contribution to these functionalities. The discovery might facilitate the bioengineered rFVIIIs and gene therapeutics.
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Affiliation(s)
- Zhang Jun
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China.
| | - Lin Ming-Ming
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China
| | - Zhang Qian-Qing
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China
| | - Wang Yun-Hong
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China
| | - Zhu Chong-Yang
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China
| | - Li Xin
- Institute of Molecular Medicine and Oncology, Chongqing Medical University, Chongqing, 400016, China
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13
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Rodriguez M, Porada CD, Almeida-Porada G. Mechanistic Insights into Factor VIII Immune Tolerance Induction via Prenatal Cell Therapy in Hemophilia A. CURRENT STEM CELL REPORTS 2019; 5:145-161. [PMID: 32351874 DOI: 10.1007/s40778-019-00165-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Purpose of Review Prenatal stem cell and gene therapy approaches are amongst the few therapies that can promise the birth of a healthy infant with specific known genetic diseases. This review describes fetal immune cell signaling and its potential influence on donor cell engraftment, and summarizes mechanisms of central T cell tolerance to peripherally-acquired antigen in the context of prenatal therapies for Hemophilia A. Recent Findings During early gestation, different subsets of antigen presenting cells take up peripherally-acquired, non-inherited antigens and induce the deletion of antigen-reactive T-cell precursors in the thymus, demonstrating the potential for using prenatal cell and gene therapies to induce central tolerance to FVIII in the context of prenatal diagnosis/therapy of Hemophilia A. Summary Prenatal cell and gene therapies are promising approaches to treat several genetic disorders including Hemophilia A and B. Understanding the mechanisms of how FVIII-specific tolerance is achieved during ontogeny could help develop novel therapies for HA and better approaches to overcome FVIII inhibitors.
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Affiliation(s)
- Martin Rodriguez
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Christopher D Porada
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Graҫa Almeida-Porada
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
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14
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Rodríguez MC, Ceaglio N, Antuña S, Tardivo MB, Etcheverrigaray M, Prieto C. Production of Therapeutic Enzymes by Lentivirus Transgenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1148:25-54. [PMID: 31482493 DOI: 10.1007/978-981-13-7709-9_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Since ERT for several LSDs treatment has emerged at the beginning of the 1980s with Orphan Drug approval, patients' expectancy and life quality have been improved. Most LSDs treatment are based on the replaced of mutated or deficient protein with the natural or recombinant protein.One of the main ERT drawback is the high drug prices. Therefore, different strategies trying to optimize the global ERT biotherapeutic production have been proposed. LVs, a gene delivery tool, can be proposed as an alternative method to generate stable cell lines in manufacturing of recombinant proteins. Since LVs have been used in human gene therapy, clinical trials, safety testing assays and procedures have been developed. Moreover, one of the main advantages of LVs strategy to obtain manufacturing cell line is the short period required as well as the high protein levels achieved.In this chapter, we will focus on LVs as a recombinant protein production platform and we will present a case study that employs LVs to express in a manufacturing cell line, alpha-Galactosidase A (rhαGAL), which is used as ERT for Fabry disease treatment.
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Affiliation(s)
| | - Natalia Ceaglio
- Cell Culture Laboratory, UNL, CONICET, FBCB, Santa Fe, Argentina
| | | | | | | | - Claudio Prieto
- Cell Culture Laboratory, UNL, FBCB, Santa Fe, Argentina.
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15
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Mannully S, L.N. R, Pulicherla K. Perspectives on progressive strategies and recent trends in the production of recombinant human factor VIII. Int J Biol Macromol 2018; 119:496-504. [DOI: 10.1016/j.ijbiomac.2018.07.164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/11/2018] [Accepted: 07/26/2018] [Indexed: 10/28/2022]
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16
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Pipe SW. Bioengineered molecules for the management of haemophilia: Promise and remaining challenges. Haemophilia 2018; 24 Suppl 6:68-75. [PMID: 29878662 DOI: 10.1111/hae.13507] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2018] [Indexed: 12/14/2022]
Abstract
Recombinant DNA technology has led to accelerating introduction of novel therapeutics for the treatment of haemophilia. This technology has driven the development of recombinant clotting factors, extended half-life clotting factors, alternative biologics to promote haemostasis and enabled the launch of the gene therapy era for haemophilia. At the core of this technology is the ability to study the structure and function of the native molecules and to apply rational bioengineering to overcome limitations to the existing therapies. Through the study of haemophilia-causing mutations, site-directed mutagenesis, detailed structural models and a wide repertoire of animal models, new bioengineering strategies are helping overcome some of the remaining limitations and challenges of traditional clotting factor concentrates. Some of these bioengineering strategies are now being partnered with improvements in vectorology leading to the first wave of successful gene therapy approaches. This study will review past and present bioengineered molecules that are advancing care for haemophilia as well as novel approaches that promise to continue to improve care and outcomes for patients with haemophilia.
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Affiliation(s)
- S W Pipe
- University of Michigan, Ann Arbor, MI, USA
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17
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Abstract
Hemophilia is a congenital bleeding disorder that affects nearly half a million individuals worldwide. Joint bleeding and other co-morbidities are a significant source of debilitation for this population. Current therapies are effective but must be given lifelong at regular intervals, are costly, and are available to only about 25% of the hemophilia population living in resource-rich countries. Gene therapy for hemophilia has been in development for three decades and is now entering pivotal-stage clinical trials. While many different technology platforms exist for gene therapy, all current clinical trials for hemophilia employ adeno-associated vector (AAV)-based cell transduction. This small viral particle is capable of packaging modified F8 or F9 transgenes, can be generated robustly from cell lines, and transduces several relatively end-differentiated target tissues such as the liver with high efficiency. While pre-existing neutralizing antibodies to the AAV capsid are recognized to limit current therapy, other challenges have been identified in human studies that were not seen in preclinical studies. Both liver transaminase elevations and immune-mediated loss of transgene expression have been observed in clinical trials. Toll-like receptors, cytotoxic T cells, and other components of the immune response have been implicated in the loss of factor expression, but a full understanding of the immune response awaits clarification. Despite these challenges, many patients enrolled in gene therapy trials have attained long-term expression of factors VIII and IX. This emerging technology now represents a cure for the severe bleeding and joint damage associated with hemophilia.
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Affiliation(s)
- John C Chapin
- Shire, 650 Kendall Drive, Cambridge, MA, 02142, USA.
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18
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Dovlatova N, Heptinstall S. Platelet aggregation measured by single-platelet counting and using PFA-100 devices. Platelets 2018; 29:656-661. [PMID: 29985716 DOI: 10.1080/09537104.2018.1492109] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Platelets play a crucial role in haemostasis and thrombosis and evaluation of platelet function in vitro, in particular platelet aggregation responses, has been one of the most common and useful ways of evaluating the risk of bleeding and thrombotic events and assessing the effects of various compounds and conditions on platelets. Traditional approaches to assessing platelet aggregation require specialised equipment and trained laboratory personnel and have other limitations. Studying platelet aggregation in whole blood offers a more physiologically relevant measurement. Additionally, certain approaches could be more widely available than in specialised laboratories. Here we summarise the application of the platelet function analyser (PFA-100), an accessible first point-of-care test for platelet function in whole blood, and the less established, but promising approach of assessing platelet aggregation by single-platelet counting that can also be performed in whole blood. The possibilities of a wider and more accessible application of the latter methodology are also discussed.
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Affiliation(s)
- Natalia Dovlatova
- a Thrombosis and Haemostasis Research Group, Division of Clinical Neuroscience , University of Nottingham , Nottingham, United Kingdom.,b Platelet Solutions Ltd ., Nottingham , United Kingdom
| | - Stan Heptinstall
- a Thrombosis and Haemostasis Research Group, Division of Clinical Neuroscience , University of Nottingham , Nottingham, United Kingdom.,b Platelet Solutions Ltd ., Nottingham , United Kingdom
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19
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Arruda VR, Doshi BS, Samelson-Jones BJ. Emerging therapies for hemophilia: controversies and unanswered questions. F1000Res 2018; 7. [PMID: 29770199 PMCID: PMC5931262 DOI: 10.12688/f1000research.12491.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2018] [Indexed: 12/21/2022] Open
Abstract
Several new therapies for hemophilia have emerged in recent years. These strategies range from extended half-life factor replacement products and non-factor options with improved pharmacokinetic profiles to gene therapy aiming for phenotypic cure. While these products have the potential to change hemophilia care dramatically, several challenges and questions remain regarding broader applicability, long-term safety, and which option to pursue for each patient. Here, we review these emerging therapies with a focus on controversies and unanswered questions in each category.
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Affiliation(s)
- Valder R Arruda
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, PA, USA
| | - Bhavya S Doshi
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Benjamin J Samelson-Jones
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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20
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Molecular mechanisms of missense mutations that generate ectopic N-glycosylation sites in coagulation factor VIII. Biochem J 2018; 475:873-886. [PMID: 29444815 DOI: 10.1042/bcj20170884] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/07/2018] [Accepted: 02/14/2018] [Indexed: 11/17/2022]
Abstract
N-glycosylation is a common posttranslational modification of secreted and membrane proteins, catalyzed by the two enzymatic isoforms of the oligosaccharyltransferase, STT3A and STT3B. Missense mutations are the most common mutations in inherited diseases; however, missense mutations that generate extra, non-native N-glycosylation sites have not been well characterized. Coagulation factor VIII (FVIII) contains five consensus N-glycosylation sites outside its functionally dispensable B domain. We developed a computer program that identified hemophilia A mutations in FVIII that can potentially create ectopic glycosylation sites. We determined that 18 of these ectopic sites indeed become N-glycosylated. These sites span the domains of FVIII and are primarily associated with a severe disease phenotype. Using STT3A and STT3B knockout cells, we determined that ectopic glycosylation exhibited different degrees of dependence on STT3A and STT3B. By separating the effects of ectopic N-glycosylation from those due to underlying amino acid changes, we showed that ectopic glycans promote the secretion of some mutants, but impair the secretion of others. However, ectopic glycans that enhanced secretion could not functionally replace a native N-glycan in the same domain. Secretion-deficient mutants, but not mutants with elevated secretion levels, show increased association with the endoplasmic reticulum chaperones BiP (immunoglobulin heavy chain-binding protein) and calreticulin. Though secreted to different extents, all studied mutants exhibited lower relative activity than wild-type FVIII. Our results reveal differential impacts of ectopic N-glycosylation on FVIII folding, trafficking and activity, which highlight complex disease-causing mechanisms of FVIII missense mutations. Our findings are relevant to other secreted and membrane proteins with mutations that generate ectopic N-glycans.
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21
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Ettinger RA, Liberman JA, Gunasekera D, Puranik K, James EA, Thompson AR, Pratt KP. FVIII proteins with a modified immunodominant T-cell epitope exhibit reduced immunogenicity and normal FVIII activity. Blood Adv 2018; 2:309-322. [PMID: 29444872 PMCID: PMC5858479 DOI: 10.1182/bloodadvances.2017013482] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/16/2018] [Indexed: 02/08/2023] Open
Abstract
Factor VIII (FVIII)-neutralizing antibodies (inhibitors) are a serious complication in hemophilia A (HA). The peptide FVIII2194-2213 contains an immunodominant HLA-DRA*01-DRB1*01:01 (DRB1*01:01)-restricted epitope recognized by CD4+ T-effector cells from HA subjects. The aim of this study was to identify amino acid substitutions to deimmunize this epitope while retaining procoagulant function and expression levels comparable to those of wild-type (WT) FVIII proteins. The shortest DRB1*01:01-binding peptide was FVIII2194-2205, and residues important for affinity were identified as F2196, M2199, A2201, and S2204. T-cell proliferation experiments with Ala-substituted FVIII2194-2205 peptides identified F2196A as a substitution that abrogated proliferation of clones specific for the WT sequence. T-cell clones that were stimulated by recombinant WT-FVIII-C2 (rWT-FVIII-C2) protein did not proliferate when cultured with rFVIII-C2-F2196A, indicating the immunogenic peptide includes a naturally processed T-cell epitope. Additional amino acid substitutions at F2196 and M2199 were evaluated by peptide-MHC class II (MHCII)-binding assays, T-cell proliferation assays, epitope prediction algorithms, and sequence homologies. Six B-domain-deleted (BDD)-FVIII proteins with substitutions F2196A, F2196L, F2196K, M2199A, M2199W, or M2199R were produced. Proliferation of T-cell clones and polyclonal lines in response to rBDD-FVIII-F2196K and rBDD-FVIII-M2199A was reduced compared with responses to WT-BDD-FVIII. The BDD-FVIII-F2196K sequence modification appears to be the most promising sequence variant tested here, due to its effectiveness at eliminating DRB1*01:01-restricted immunogenicity, low potential immunogenicity in the context of other MHCII alleles, expression level comparable to WT-BDD-FVIII, and retained procoagulant activity. These results provide proof of principle for the design of less immunogenic FVIII proteins targeted to specific subsets of HA patients.
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Affiliation(s)
- Ruth A Ettinger
- Bloodworks Northwest Research Institute, Seattle, WA
- Benaroya Research Institute, Seattle, WA
| | | | - Devi Gunasekera
- Bloodworks Northwest Research Institute, Seattle, WA
- Uniformed Services University of the Health Sciences, Bethesda, MD; and
| | - Komal Puranik
- Bloodworks Northwest Research Institute, Seattle, WA
| | | | - Arthur R Thompson
- Bloodworks Northwest Research Institute, Seattle, WA
- Division of Hematology, Department Medicine, University of Washington, Seattle, WA
| | - Kathleen P Pratt
- Bloodworks Northwest Research Institute, Seattle, WA
- Uniformed Services University of the Health Sciences, Bethesda, MD; and
- Division of Hematology, Department Medicine, University of Washington, Seattle, WA
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