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Shestopal SA, Parunov LA, Olivares P, Chun H, Ovanesov MV, Pettersson JR, Sarafanov AG. Isolated Variable Domains of an Antibody Can Assemble on Blood Coagulation Factor VIII into a Functional Fv-like Complex. Int J Mol Sci 2022; 23:ijms23158134. [PMID: 35897712 PMCID: PMC9330781 DOI: 10.3390/ijms23158134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 11/29/2022] Open
Abstract
Single-chain variable fragments (scFv) are antigen-recognizing variable fragments of antibodies (FV) where both subunits (VL and VH) are connected via an artificial linker. One particular scFv, iKM33, directed against blood coagulation factor VIII (FVIII) was shown to inhibit major FVIII functions and is useful in FVIII research. We aimed to investigate the properties of iKM33 enabled with protease-dependent disintegration. Three variants of iKM33 bearing thrombin cleavage sites within the linker were expressed using a baculovirus system and purified by two-step chromatography. All proteins retained strong binding to FVIII by surface plasmon resonance, and upon thrombin cleavage, dissociated into VL and VH as shown by size-exclusion chromatography. However, in FVIII activity and low-density lipoprotein receptor-related protein 1 binding assays, the thrombin-cleaved iKM33 variants were still inhibitory. In a pull-down assay using an FVIII-affinity sorbent, the isolated VH, a mixture of VL and VH, and intact iKM33 were carried over via FVIII analyzed by electrophoresis. We concluded that the isolated VL and VH assembled into scFv-like heterodimer on FVIII, and the isolated VH alone also bound FVIII. We discuss the potential use of both protease-cleavable scFvs and isolated Fv subunits retaining high affinity to the antigens in various practical applications such as therapeutics, diagnostics, and research.
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Hodeib H, El Amrousy D, Youssef A, Elaskary E, Fouda MH. BAFF rs9514828 gene polymorphism and the risk of the development of inhibitors in children with severe haemophilia A. Haemophilia 2022; 28:472-479. [PMID: 35316553 DOI: 10.1111/hae.14555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Haemophilia A (HA) is an x-linked recessive disease due to deficiency of coagulation factor VIII (FVIII). The development of neutralizing antibodies (inhibitors) against infused FVIII is a major concern. B cell activating factor (BAFF) has been implicated in several autoimmune diseases. AIM We aimed to evaluate the possible association of BAFF rs9514828 gene polymorphism and the risk of the development of FVIII inhibitor in children with severe HA. METHODS This cohort study was carried out on 100 newly diagnosed boys with severe HA who were never treated before with FVIII concentrate. Assessment of serum levels of BAFF and BAFF rs9514828 genotyping at first diagnosis was performed and the patients were followed up for the completion of a total of 50 exposure days or the development of inhibitors whichever occurred first. The patients were divided as positive or negative according to the presence or absence of inhibitors. RESULTS The risk allele for BAFF rs9514828 (T) was significantly more frequent in the inhibitor positive patients than the inhibitor negative patients (P = .003). In addition, CT+TT genotypes were associated with increased risk of FVIII inhibitor development. Receiver operating characteristics (ROC) analysis showed that BAFF levels could predict the development of FVIII inhibitors at a cut-off value of ≥ .92 with a sensitivity of 85.9% and a specificity of 80.2%. CONCLUSION BAFF rs9514828 gene polymorphism could be independent risk factor and elevated BAFF levels might be useful prognostic marker for the development of FVIII inhibitor in newly diagnosed children with severe HA.
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Affiliation(s)
- Hossam Hodeib
- Clinical Pathology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Doaa El Amrousy
- Pediatric Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Amira Youssef
- Clinical Pathology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Eman Elaskary
- Pediatric Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mohamed H Fouda
- Clinical Pathology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
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Winterling K, Martin WD, De Groot AS, Daufenbach J, Kistner S, Schüttrumpf J. Development of a novel fully functional coagulation factor VIII with reduced immunogenicity utilizing an in silico prediction and deimmunization approach. J Thromb Haemost 2021; 19:2161-2170. [PMID: 34060724 PMCID: PMC8456792 DOI: 10.1111/jth.15413] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/17/2021] [Accepted: 04/19/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Up to 30% of hemophilia A patients develop inhibitory antibodies against the infused factor VIII (FVIII). The development of a deimmunized FVIII is an unmet high medical need. Although improved recombinant FVIII (rFVIII) products evolved within the last years, the immunogenicity has not been solved. A deimmunized FVIII could reduce the probability of inhibitor development, providing safer therapy. OBJECTIVE To develop a deimmunized FVIII molecule by modifying major histocompatibility complex (MHC) class II presentation, leading to a functional but less immunogenic molecule. METHODS We performed (1) in silico prediction of potentially immunogenic T cell epitopes and their modification by amino acid substitutions in the FVIII sequence, (2) evaluation of functional and structural similarity of the modified rFVIII to unmodified FVIII and registered products, and (3) confirmation of the reduced immunogenicity by in vitro testing. RESULTS A partially deimmunized fully functional FVIII molecule incorporating 19 amino acid substitutions was generated. The substitutions led to a reduction of the immunogenicity score, indicating a reduced immunogenicity based on in silico calculations. This was confirmed in an in vitro dendritic cell (DC)--T cell assay. Using this assay, cells from healthy donors proved the significantly reduced immunogenicity of the modified FVIII variant by revealing less proliferation of T helper cells to this variant than to the unmodified FVIII. CONCLUSION In silico predictions resulted in a partially deimmunized FVIII. This FVIII is fully functional and was demonstrated to be less immunogenic in in vitro testing. This approach may result in a reduction of the inhibitor risk for patients with hemophilia A.
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Affiliation(s)
| | | | - Anne S. De Groot
- EpiVax, Inc.ProvidenceRhode IslandUSA
- Center for Vaccines and ImmunologyUniversity of GeorgiaAthensGeorgiaUSA
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Cormier M, Batty P, Tarrant J, Lillicrap D. Advances in knowledge of inhibitor formation in severe haemophilia A. Br J Haematol 2020; 189:39-53. [DOI: 10.1111/bjh.16377] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Matthew Cormier
- Department of Pathology and Molecular Medicine Richardson Laboratory Queen’s University Kingston ON Canada
| | - Paul Batty
- Department of Pathology and Molecular Medicine Richardson Laboratory Queen’s University Kingston ON Canada
| | - Julie Tarrant
- Department of Pathology and Molecular Medicine Richardson Laboratory Queen’s University Kingston ON Canada
| | - David Lillicrap
- Department of Pathology and Molecular Medicine Richardson Laboratory Queen’s University Kingston ON Canada
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Anzengruber J, Feichtinger M, Bärnthaler P, Haider N, Ilas J, Pruckner N, Benamara K, Scheiflinger F, Reipert BM, Malisauskas M. How Full-Length FVIII Benefits from Its Heterogeneity - Insights into the Role of the B-Domain. Pharm Res 2019; 36:77. [PMID: 30937539 PMCID: PMC6443606 DOI: 10.1007/s11095-019-2599-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/27/2019] [Indexed: 11/19/2022]
Abstract
Purpose To explore how the natural heterogeneity of human coagulation factor VIII (FVIII) and the processing of its B-domain specifically modulate protein aggregation. Methods Recombinant FVIII (rFVIII) molecular species containing 70% or 20% B-domain, and B-domain-deleted rFVIII (BDD-rFVIII), were separated from full-length recombinant FVIII (FL-rFVIII). Purified human plasma-derived FVIII (pdFVIII) was used as a comparator. Heterogeneity and aggregation of the various rFVIII molecular species, FL-rFVIII and pdFVIII were analysed by SDS-PAGE, dynamic light scattering, high-performance size-exclusion chromatography and flow cytometry-based particle analysis. Results FL-rFVIII and pdFVIII were heterogeneous in nature and demonstrated similar resistance to aggregation under physical stress. Differences were observed between these and among rFVIII molecular species. FVIII molecular species exhibited diverging aggregation pathways dependent on B-domain content. The propensity to form aggregates increased with decreasing proportions of B-domain, whereas the opposite was observed for oligomer formation. Development of cross-β sheet-containing aggregates in BDD-rFVIII induced effective homologous seeding and faster aggregation. Naturally heterogeneous FL-rFVIII and pdFVIII displayed the lowest propensity to aggregate in all experiments. Conclusions These results demonstrate that pdFVIII and FL-rFVIII have similar levels of molecular heterogeneity, and suggest that heterogeneity and the B-domain are involved in stabilising FVIII by modulating its aggregation pathway. Electronic supplementary material The online version of this article (10.1007/s11095-019-2599-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julia Anzengruber
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria.
| | - Martin Feichtinger
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Philipp Bärnthaler
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Norbert Haider
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Josenato Ilas
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Nina Pruckner
- Technical Operations, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Karima Benamara
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | | | - Birgit M Reipert
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
| | - Mantas Malisauskas
- Research & Development, Baxalta Innovations GmbH, a Takeda company, Vienna, Austria
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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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Hyun SY, Park SY, Lee SY, Kook H, Paik SH, Jang IJ, Lee KS. Efficacy, Safety, and Pharmacokinetics of Beroctocog Alfa in Patients Previously Treated for Hemophilia A. Yonsei Med J 2015; 56:935-43. [PMID: 26069114 PMCID: PMC4479860 DOI: 10.3349/ymj.2015.56.4.935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Beroctocog alfa is a second generation recombinant factor VIII manufactured by removing the B-domain from factor VIII. This prospective clinical trial was conducted to evaluate the efficacy, safety, and pharmacokinetics of beroctocog alfa in patients of ages ≥12 years previously treated for severe hemophilia A. MATERIALS AND METHODS Seventy subjects received beroctocog alfa as an on-demand treatment for acute hemorrhage. RESULTS The final hemostatic effect was excellent in 35 subjects (50%) and good in 26 subjects (37.1%). The drug showed an overall efficacy rate of 87.1%. The majority of acute hemorrhages was treated by administering the study drug once (86.2%) or twice (10.0%), and the mean dose administered per single infusion was 28.55±6.53 IU/kg. Ten subjects underwent 12 surgical procedures, and hemostatic efficacy was excellent in seven cases (58.3%) and good in five cases (41.7%), showing a 100% efficacy rate. A total of 52 of 88 subjects (59.0%) experienced 168 adverse events. There were 18 serious adverse events (10.7%) in 11 subjects, and two (mild dyspnea and facial edema) in one subject were related to the study drug. Only one subject formed a de novo factor VIII inhibitor, for an occurrence rate of 1.4% (one-sided 95% upper confidence limit: 3.85%). The final elimination half-life was 13.3 h and 12.6 h at baseline and 6 months after administration, respectively. CONCLUSION Our results suggest that beroctocog alfa is safe and efficacious as either an on-demand treatment for acute hemorrhage or a surgical prophylaxis in patients with hemophilia A.
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Affiliation(s)
- Shin Young Hyun
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Seon Yang Park
- Department of Hematology and Oncology, Seoul National University College of Medicine, Seoul, Korea
| | - Soon Yong Lee
- Department of Pediatrics, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea
| | - Hoon Kook
- Department of Pediatrics, Chonnam National University Hwasun Hospital, Hwasun, Korea
| | - Sang Hoon Paik
- Green Cross Research Center, Green Cross Corporation, Yongin, Korea
| | - In-Jin Jang
- Department of Clinical Pharmacology & Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea
| | - Kun Soo Lee
- Department of Pediatrics, Kyungpook National University School of Medicine, Daegu, Korea.
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Classic and alternative red blood cell storage strategies: seven years of "-omics" investigations. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2014; 13:21-31. [PMID: 25369599 DOI: 10.2450/2014.0053-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/13/2014] [Indexed: 12/12/2022]
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Ezban M, Vad K, Kjalke M. Turoctocog alfa (NovoEight®)--from design to clinical proof of concept. Eur J Haematol 2014; 93:369-76. [PMID: 24797664 PMCID: PMC4232928 DOI: 10.1111/ejh.12366] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2014] [Indexed: 11/29/2022]
Abstract
Turoctocog alfa (NovoEight®) is a recombinant factor VIII (rFVIII) with a truncated B-domain made from the sequence coding for 10 amino acids from the N-terminus and 11 amino acids from the C-terminus of the naturally occurring B-domain. Turoctocog alfa is produced in Chinese hamster ovary (CHO) cells without addition of any human- or animal-derived materials. During secretion, some rFVIII molecules are cleaved at the C-terminal of the heavy chain (HC) at amino acid 720, and a monoclonal antibody binding C-terminal to this position is used in the purification process allowing isolation of the intact rFVIII. Viral inactivation is ensured by a detergent inactivation step as well as a 20-nm nano-filtration step. Characterisation of the purified protein demonstrated that turoctocog alfa was fully sulphated at Tyr346 and Tyr1664, which is required for optimal proteolytic activation by thrombin. Kinetic assessments confirmed that turoctocog alfa was activated by thrombin at a similar rate as seen for other rFVIII products fully sulphated at these positions. Tyr1680 was also fully sulphated in turoctocog alfa resulting in strong affinity (low nm Kd) for binding to von Willebrand factor (VWF). Half-lives of 7.2 ± 0.9 h in F8-KO mice and 8.9 ± 1.8 h haemophilia A dogs supported that turoctocog alfa bound to VWF after infusion. Functional studies including thromboelastography analysis of human haemophilia A whole blood with added turoctocog alfa and effect studies in mice bleeding models demonstrated a dose-dependent effect of turoctocog alfa. The non-clinical data thus confirm the haemostatic effect of turoctocog alfa and, together with the comprehensive clinical evaluation, support the use as FVIII replacement therapy in patients with haemophilia A.
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Stewart JM, Tarantal AF, Hawthorne WJ, Salvaris EJ, O'Connell PJ, Nottle MB, d'Apice AJF, Cowan PJ, Kearns-Jonker M. Rhesus monkeys and baboons develop clotting factor VIII inhibitors in response to porcine endothelial cells or islets. Xenotransplantation 2014; 21:341-52. [PMID: 24806998 DOI: 10.1111/xen.12100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/14/2014] [Indexed: 01/15/2023]
Abstract
BACKGROUND Xenotransplantation of porcine organs holds promise of solving the human organ donor shortage. The use of α-1,3-galactosyltransferase knockout (GTKO) pig donors mitigates hyperacute rejection, while delayed rejection is currently precipitated by potent immune and hemostatic complications. Previous analysis by our laboratory suggests that clotting factor VIII (FVIII) inhibitors might be elicited by the structurally restricted xenoantibody response which occurs after transplantation of either pig GTKO/hCD55/hCD59/hHT transgenic neonatal islet cell clusters or GTKO endothelial cells. METHODS A recombinant xenoantibody was generated using sequences from baboons demonstrating an active xenoantibody response at day 28 after GTKO/hCD55/hCD59/hHT transgenic pig neonatal islet cell cluster transplantation. Rhesus monkeys were immunized with GTKO pig endothelial cells to stimulate an anti-non-Gal xenoantibody response. Serum was collected at days 0 and 7 after immunization. A two-stage chromogenic assay was used to measure FVIII cofactor activity and identify antibodies which inhibit FVIII function. Molecular modeling and molecular dynamics simulations were used to predict antibody structure and the residues which contribute to antibody-FVIII interactions. Competition ELISA was used to verify predictions at the domain structural level. RESULTS Antibodies that inhibit recombinant human FVIII function are elicited after non-human primates are transplanted with either GTKO pig neonatal islet cell clusters or endothelial cells. There is an apparent increase in inhibitor titer by 15 Bethesda units (Bu) after transplant, where an increase greater than 5 Bu can indicate pathology in humans. Furthermore, competition ELISA verifies the computer modeled prediction that the recombinant xenoantibody, H66K12, binds the C1 domain of FVIII. CONCLUSIONS The development of FVIII inhibitors is a novel illustration of the potential impact the humoral immune response can have on coagulative dysfunction in xenotransplantation. However, the contribution of these antibodies to rejection pathology requires further evaluation because "normal" coagulation parameters after successful xenotransplantation are not fully understood.
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Affiliation(s)
- John M Stewart
- Division of Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA
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Paik SH, Kim YJ, Han SK, Kim JY, Park H, Park YI. Comparability studies of new 3rd generation recombinant human factor VIII GreenGene F after improvement of formulation and viral inactivation/removal process. Biologicals 2012; 40:405-14. [DOI: 10.1016/j.biologicals.2012.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 07/27/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022] Open
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Paik SH, Kim YJ, Han SK, Kim JM, Huh JW, Park YI. Mixture of three amino acids as stabilizers replacing albumin in lyophilization of new third generation recombinant factor VIII GreenGene F. Biotechnol Prog 2012; 28:1517-25. [PMID: 23011837 DOI: 10.1002/btpr.1640] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 08/31/2012] [Indexed: 01/30/2023]
Abstract
A formulation with stabilizers replacing albumin was developed for lyophilization of recombinant factor VIII (FVIII), GreenGene F (WHO INN: beroctocog alfa), to achieve stability and eliminate safety issues of blood-derived albumin. L-Arginine (hydrophilic amino acid, positively charged side chain), L-glutamic acid (hydrophilic amino acid, negatively charged side chain), and L-isoleucine (hydrophobic amino acid, nonpolar) were selected as stabilizers, and the mixture of the three amino acids were optimized. The mixture had results comparative with albumin and other commonly used stabilizers showing good preservation of recombinant FVIII during lyophilization, robust stability with consistently high recovery of FVIIII, very low aggregate formation, and good storage stability without alterations in protein characteristics. In vivo test results showed that the efficacy was maintained and had no signs of toxicity. The study demonstrated that the three amino acid mixture acts as a good stabilizer for lyophilization of recombinant FVIII and as a safe excipient.
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Affiliation(s)
- Sang Hoon Paik
- GC-Research Center, Green Cross Corporation, 341 Bojeong-dong, Giheung-gu, Yongin, Korea.
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Blasi B, D'Amici GM, D'Alessandro A, Zolla L. Native analysis of plasma-derived clotting factor VIII concentrates: "sponge effect" and contaminants. Electrophoresis 2012; 33:1292-8. [PMID: 22589109 DOI: 10.1002/elps.201100702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In the present study, we analysed two commercially available plasma-derived FVIII preparations, Beriate and Emoclot, through native gel-based approaches (CN-PAGE). The rationale behind this study was to assess whether protein complexes from plasma resisted the aggressive manufacturing processes. A preliminary analysis of plasma complexes was performed focusing on the molecular weight range between 45 kDa and 1 MDa. As a result, we could evidence in both preparations the presence of complexes, which resisted the cryoprecipitation, chromatographic and heat treatment processing steps. These complexes behaved in a "sponge-effect"-like fashion through the enrichment of otherwise less abundant contaminants. The use of an alternative electrophoretic approach such as CN-PAGE allowed us to confirm 2DE-based observations and expand the list of non-FVIII proteins which contaminate the preparations.
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Affiliation(s)
- Barbara Blasi
- Department of Environmental Sciences, Tuscia University, Viterbo, Italy
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D'Amici GM, Blasi B, D'Alessandro A, Vaglio S, Zolla L. Plasma-derived clotting factor VIII: heterogeneity evaluation in the quest for potential inhibitory-antibody stimulating factors. Electrophoresis 2011; 32:2941-50. [PMID: 21997645 DOI: 10.1002/elps.201100246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/08/2011] [Accepted: 06/09/2011] [Indexed: 12/26/2022]
Abstract
In this study, we investigated the heterogeneity and the purity grade of three commercially available plasma-derived clotting factor VIII (FVIII) concentrates, which highly differ with regard to purification strategies, relative concentrations of stabilizers (von Willebrand factor, with or without albumin) and virus inactivation strategies (solvent/detergent and/or heat/pasteurization treatments). Western blot analyses were used to evaluate product-specific variations from Emoclot(®) , Alphanate(®) and Haemate(®) both in the presence and absence of reducing agents (dithiotreithol). All the plasma-derived concentrates showed a strong heterogeneity, as they all included a significant amount of truncated forms of the full-length (FL) clotting FVIII protein. The intact protein accounted for the 38% of the total FVIII proteins in Haemate(®) and 29 and 23% in Alphanate(®) and Emoclot(®) , respectively. Lower intact FVIII amounts in Emoclot might be mainly due to the low von Willebrand factor dosage and the absence of albumin. Upon addition of thrombin, both the FL and truncated forms of the FVIII protein were almost completely digested. Indeed, after thrombin activation, we could still observe a mixture of B-domain truncated forms of the FL protein along with biologically active digested-A1 forms. Batch-to-batch variation was tested with no evident changes appearing among different batches. Despite the variables in manufacturing processes, inter-product comparisons yielded similar results for all the plasma-derived FVIII considered in this study. However, we could individuate in Emoclot a band that was not digested by thrombin, which we could characterize as the 200 kDa FVIII heavy chain. This investigation prompts new concerns about the strong heterogeneity observed upon thrombin digestion of plasma-derived FVIII, which might contribute to the development of inhibitory antibodies at an early stage of therapy, and to which extent these untoward phenomena could be avoided through direct intervention on routine manufacturing processes.
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Affiliation(s)
- Gian M D'Amici
- Department of Environmental Sciences, Tuscia University, Viterbo, Italy
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Gaso-Sokac D, Kovac S, Clifton J, Josic D. Therapeutic plasma proteins--application of proteomics in process optimization, validation, and analysis of the final product. Electrophoresis 2011; 32:1104-17. [PMID: 21544836 DOI: 10.1002/elps.201000641] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
An overview is given on the application of proteomic technology in the monitoring of different steps during the production of therapeutic proteins from human plasma. Recent advances in this technology enable the use of proteomics as an advantageous tool for the validation of already existing processes, the development and fine tuning of new production steps, the characterization and quality control of final products, the detection of both harmful impurities and modifications of the therapeutic protein and the auditing of batch-to-batch variations. Further, use of proteomics for preclinical testing of new products, which can be either recombinant or plasma-derived, is also discussed.
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Affiliation(s)
- Dajana Gaso-Sokac
- Department of Chemistry, J. J. Strossmayer Univeristy, Osijek, Croatia
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Structural analysis of the recombinant therapeutic product rFVIII and its PEGylated variants using 2-D DIGE. Electrophoresis 2011; 32:1292-301. [DOI: 10.1002/elps.201000627] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 12/29/2010] [Accepted: 01/10/2011] [Indexed: 11/07/2022]
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