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Kalandadze V, Di Simone PE, Mohammed I, Murari D, Follenzi A, Borsotti C. Elevated memory T-cell conversion in a preclinical mouse model of hemophilia A. Eur J Immunol 2024:e2350807. [PMID: 38873896 DOI: 10.1002/eji.202350807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 05/27/2024] [Accepted: 05/31/2024] [Indexed: 06/15/2024]
Abstract
One of the major challenges in the choice of the best therapeutic approach for the treatment of patients affected by hemophilia A (HA) is the definition of criteria predicting the formation of factor VIII (FVIII) neutralizing antibodies, called inhibitors. Both genetic and environmental elements influencing the immune response toward FVIII have been identified but still not all the factors causing the pathological rejection of FVIII have been identified. Since there is a connection between coagulation and inflammation, here we assessed the role played by the FVIII deficiency in shaping the humoral and cellular response toward an antigen other than FVIII itself. To this aim, we challenged both HA and wild-type (WT) mice with either FVIII or ovalbumin (OVA) and followed antigen-specific antibody level, immune cell population frequency and phenotype up to 9 weeks after the last antigen booster. The activation threshold was evaluated in vitro by stimulating the murine T cells with a decreasing dose of α-CD3. The humoral response to FVIII was similar between the two groups while both the in vivo and in vitro experiments highlighted an antigen-independent sensitivity of HA compared with WT T cells causing an increase in memory T-cell conversion and proliferation capability.
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Affiliation(s)
- Vakhtang Kalandadze
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Paolo E Di Simone
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | | | - Daniele Murari
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Antonia Follenzi
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Chiara Borsotti
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
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2
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Pratt KP, Gunasekera D, Vir P, Tan S, Pierce GF, Olsen C, Butenas S, Mann KG. Anti-FVIII antibodies in Black and White hemophilia A subjects: do F8 haplotypes play a role? Blood Adv 2023; 7:4983-4998. [PMID: 36459498 PMCID: PMC10471934 DOI: 10.1182/bloodadvances.2021004909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 09/28/2022] [Accepted: 10/12/2022] [Indexed: 12/04/2022] Open
Abstract
The most common complication in hemophilia A (HA) treatment, affecting 25% to 30% of patients with severe HA, is the development of alloimmune inhibitors that foreclose the ability of infused factor VIII (FVIII) to participate in coagulation. Inhibitors confer significant pathology on affected individuals and present major complexities in their management. Inhibitors are more common in African American patients, and it has been hypothesized that this is a consequence of haplotype (H)-treatment product mismatch. F8 haplotypes H1 to H5 are defined by nonsynonymous single-nucleotide polymorphisms encoding sequence variations at FVIII residues 1241, 2238, and 484. Haplotypes H2 to H5 are more prevalent in individuals with Black African ancestry, whereas 80% to 90% of the White population has the H1 haplotype. This study used an established multiplex fluorescence immunoassay to determine anti-FVIII antibody titers in plasma from 394 individuals with HA (188 Black, 206 White), measuring their binding to recombinant full-length H1 and H2 and B-domain-deleted (BDD) H1/H2, H3/H5, and H4 FVIII proteins. Inhibitor titers were determined using a chromogenic assay and linear B-cell epitopes characterized using peptide microarrays. FVIII-reactive antibodies were readily detected in most individuals with HA, with higher titers in those with a current inhibitor, as expected. Neither total nor inhibitory antibody titers correlated with F8 haplotype mismatches, and peptides with D1241E and M2238V polymorphisms did not comprise linear B-cell epitopes. Interestingly, compared with the full-length FVIII products, the BDD-FVIII proteins were markedly more reactive with plasma antibodies. The stronger immunoreactivity of BDD-FVIII suggests that B-domain removal might expose novel B-cell epitopes, perhaps through conformational rearrangements of FVIII domains.
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Affiliation(s)
| | - Devi Gunasekera
- Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Pooja Vir
- Uniformed Services University of the Health Sciences, Bethesda, MD
| | | | - Glenn F. Pierce
- Independent Consultant, La Jolla, CA
- World Federation of Hemophilia, Montreal, QC, Canada
| | - Cara Olsen
- Uniformed Services University of the Health Sciences, Bethesda, MD
| | | | - Kenneth G. Mann
- College of Medicine, University of Vermont, Burlington, VT
- Haematologic Technologies, Inc, Colchester, VT
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3
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Gunasekera D, Vir P, Karim AF, Ragni MV, Pratt KP. Hemophilia A subjects with an intron-22 gene inversion mutation show CD4 + T-effector responses to multiple epitopes in FVIII. Front Immunol 2023; 14:1128641. [PMID: 36936969 PMCID: PMC10015889 DOI: 10.3389/fimmu.2023.1128641] [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: 12/21/2022] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
Background Almost half of severe hemophilia A (HA) is caused by an intron 22 inversion mutation (Int22Inv), which disrupts the 26-exon F8 gene. Inverted F8 mRNA exons 1-22 are transcribed, while F8B mRNA, containing F8 exons 23-26, is transcribed from a promoter within intron 22. Neither FVIII activity nor FVIII antigen (cross-reacting material, CRM) are detectable in plasma of patients with an intron-22 inversion. Objectives To test the hypothesis that (putative) intracellular synthesis of FVIII proteins encoded by inverted F8 and F8B mRNAs confers T-cell tolerance to almost the entire FVIII sequence, and to evaluate the immunogenicity of the region encoded by the F8 exon 22-23 junction sequence. Patients/Methods Peripheral blood mononuclear cells (PBMCs) from 30 severe or moderate HA subjects (17 with an Int22Inv mutation) were tested by ELISPOT assays to detect cytokine secretion in response to FVIII proteins and peptides and to map immunodominant T-cell epitopes. Potential immunogenicity of FVIII sequences encoded by the F8 exon 22-23 junction region was also tested using peptide-MHCII binding assays. Results Eight of the Int22Inv subjects showed robust cytokine secretion from PBMCs stimulated with FVIII proteins and/or peptides, consistent with earlier publications from the Conti-Fine group. Peptide ELISPOT assays identified immunogenic regions of FVIII. Specificity for sequences encoded within F8 mRNA exons 1-22 and F8B mRNA was confirmed by staining Int22Inv CD4+ T cells with peptide-loaded HLA-Class II tetramers. FVIII peptides spanning the F8 exon 22-23 junction (encoding M2124-V2125) showed limited binding to MHCII proteins and low immunogenicity, with cytokine secretion from only one Int22Inv subject. Conclusions PBMCs from multiple subjects with an Int22Inv mutation, with and without a current FVIII inhibitor, responded to FVIII epitopes. Furthermore, the FVIII region encoded by the exon 22-23 junction sequence was not remarkably immunoreactive and is therefore unlikely to contain an immunodominant, promiscuous CD4+ T-cell epitope. Our results indicate that putative intracellular expression of partial FVIII proteins does not confer T-cell tolerance to FVIII regions encoded by inverted F8 mRNA or F8B mRNA.
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Affiliation(s)
- Devi Gunasekera
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Pooja Vir
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Ahmad Faisal Karim
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Margaret V. Ragni
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kathleen P. Pratt
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- *Correspondence: Kathleen P. Pratt,
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4
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Matzinger P. Autoimmunity: Are we asking the right question? Front Immunol 2022; 13:864633. [PMID: 36405714 PMCID: PMC9671104 DOI: 10.3389/fimmu.2022.864633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 09/20/2022] [Indexed: 09/07/2023] Open
Abstract
For decades, the main question immunologists have asked about autoimmunity is "what causes a break in self-tolerance?" We have not found good answers to that question, and I believe we are still so ignorant because it's the wrong question. Rather than a break in self-tolerance, I suggest that many autoimmune diseases might be due to defects in normal tissue physiology.
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Affiliation(s)
- Polly Matzinger
- Ghost Lab, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, Bethesda, MD, United States
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5
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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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6
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Role of Regulatory Cells in Immune Tolerance Induction in Hemophilia A. Hemasphere 2021; 5:e557. [PMID: 33898928 PMCID: PMC8061682 DOI: 10.1097/hs9.0000000000000557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/09/2021] [Indexed: 11/26/2022] Open
Abstract
The main complication of hemophilia A treatment is the development of neutralizing antibodies (inhibitors) against factor VIII (FVIII). Immune tolerance induction (ITI) is the prescribed treatment for inhibitor eradication, although its working mechanism remains unresolved. To clarify this mechanism, we compared blood samples of hemophilia A patients with and without inhibitors for presence of immunoregulatory cells and markers, including regulatory B-cells (Bregs), regulatory T-cells (Tregs), myeloid-derived suppressor cells (MDSCs), and expression of regulatory markers on T-cells (programmed cell death protein 1 [PD1], inducable T-cell costimulator, cytotoxic T-lymphocyte-associated protein 4 [CTLA4]), by use of flow cytometry. By cross-sectional analysis inhibitor patients (N = 20) were compared with inhibitor-negative (N = 28) and ex-inhibitor (N = 17) patients. In another longitudinal study, changes in immunoregulatory parameters were evaluated during ITI (N = 12) and compared with inhibitor-negative hemophilia A patients (N = 36). The frequency of Bregs, but not of Tregs nor MDSCs, was significantly reduced in inhibitor patients (3.2%) compared with inhibitor-negative (5.9%) and ex-inhibitor patients (8.9%; P < 0.01). CTLA4 expression on T-cells was also reduced (mean fluorescence intensity 133 in inhibitor versus 537 in inhibitor-negative patients; P < 0.01). Fittingly, in patients followed during ITI, inhibitor eradication associated with increased Bregs, increased Tregs, and increased expression of CTLA4 and PD1 on CD4+ T-cells. In conclusion, inhibitor patients express significantly lower frequency of Bregs and Tregs marker expression, which are restored by successful ITI. Our findings suggest that an existing anti-FVIII immune response is associated with deficits in peripheral tolerance mechanisms and that Bregs and changes in immunoregulatory properties of CD4+ T-cells likely contribute to ITI in hemophilia A patients with inhibitors.
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7
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Thachil J. Potential Clues to the Pathogenesis of Acquired Hemophilia. Semin Thromb Hemost 2021; 47:890-891. [PMID: 33647996 DOI: 10.1055/s-0040-1722294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Jecko Thachil
- Department of Haematology, Manchester University Hospitals, Manchester, United Kingdom
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8
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Karim AF, Soltis AR, Sukumar G, Königs C, Ewing NP, Dalgard CL, Wilkerson MD, Pratt KP. Hemophilia A Inhibitor Subjects Show Unique PBMC Gene Expression Profiles That Include Up-Regulated Innate Immune Modulators. Front Immunol 2020; 11:1219. [PMID: 32595650 PMCID: PMC7303277 DOI: 10.3389/fimmu.2020.01219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/15/2020] [Indexed: 12/18/2022] Open
Abstract
Formation of pathological anti-FVIII antibodies, or "inhibitors," is the most serious complication of therapeutic FVIII infusions, affecting up to 1/3 of severe Hemophilia A (HA) patients. Inhibitor formation is a classical T-cell dependent adaptive immune response. As such, it requires help from the innate immune system. However, the roles of innate immune cells and mechanisms of inhibitor development vs. immune tolerance, achieved with or without Immune Tolerance Induction (ITI) therapy, are not well-understood. To address these questions, temporal transcriptomics profiling of FVIII-stimulated peripheral blood mononuclear cells (PBMCs) was carried out for HA subjects with and without a current or historic inhibitor using RNA-Seq. PBMCs were isolated from 40 subjects in the following groups: HA with an inhibitor that resolved either following ITI or spontaneously; HA with a current inhibitor; HA with no inhibitor history and non-HA controls. PBMCs were stimulated with 5 nM FVIII and RNA was isolated 4, 16, 24, and 48 h following stimulation. Time-series differential expression analysis was performed and distinct transcriptional signatures were identified for each group, providing clues as to cellular mechanisms leading to or accompanying their disparate anti-FVIII antibody responses. Subjects with a current inhibitor showed differential expression of 56 genes and a clustering analysis identified three major temporal profiles. Interestingly, gene ontology enrichments featured innate immune modulators, including NLRP3, TLR8, IL32, CLEC10A, and COLEC12. NLRP3 and TLR8 are associated with enhanced secretion of the pro-inflammatory cytokines IL-1β and TNFα, while IL32, which has several isoforms, has been associated with both inflammatory and regulatory immune processes. RNA-Seq results were validated by RT-qPCR, ELISAs, multiplex cytokine analysis, and flow cytometry. The inflammatory status of HA patients suffering from an ongoing inhibitor includes up-regulated innate immune modulators, which may act as ongoing danger signals that influence the responses to, and eventual outcomes of, ITI therapy.
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Affiliation(s)
- Ahmad Faisal Karim
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Anthony R Soltis
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Collaborative Health Initiative Research Program, Henry Jackson Foundation for the Advancement of Military Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Gauthaman Sukumar
- Collaborative Health Initiative Research Program, Henry Jackson Foundation for the Advancement of Military Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Department of Anatomy, Physiology & Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | | | - Nadia P Ewing
- City of Hope National Medical Center, Duarte, CA, United States
| | - Clifton L Dalgard
- Collaborative Health Initiative Research Program, Henry Jackson Foundation for the Advancement of Military Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Department of Anatomy, Physiology & Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Matthew D Wilkerson
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Collaborative Health Initiative Research Program, Henry Jackson Foundation for the Advancement of Military Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.,Department of Anatomy, Physiology & Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Kathleen P Pratt
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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9
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Bou Jaoudeh M, Delignat S, Varthaman A, Lacroix-Desmazes S. [Origin and nature of the neutralizing immune response against therapeutic factor VIII]. Med Sci (Paris) 2020; 36:341-347. [PMID: 32356710 DOI: 10.1051/medsci/2020060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of therapeutic proteins induces in some patients the appearance of neutralizing antibodies. This is the case of pro-coagulant factor VIII (FVIII) used in patients with hemophilia A. Several parameters related to the protein itself, to the type of pathology or to the patients, condition the immunogenicity of a therapeutic protein. Understanding these parameters would help to anticipate or prevent the development of neutralizing antibodies. In the case of FVIII, we propose that the development of neutralizing antibodies does not result from an unpredicted immune response but rather from the inability of the patient's organism to develop an anti-inflammatory or regulatory response.
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Affiliation(s)
- Mélissa Bou Jaoudeh
- Centre de recherche des Cordeliers, Inserm, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Sandrine Delignat
- Centre de recherche des Cordeliers, Inserm, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Aditi Varthaman
- Centre de recherche des Cordeliers, Inserm, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Sébastien Lacroix-Desmazes
- Centre de recherche des Cordeliers, Inserm, Sorbonne Université, Université de Paris, F-75006, Paris, France
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10
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Matino D, Afraz S, Zhao G, Tieu P, Gargaro M, Fallarino F, Iorio A. Tolerance to FVIII: Role of the Immune Metabolic Enzymes Indoleamine 2,3 Dyoxigenase-1 and Heme Oxygenase-1. Front Immunol 2020; 11:620. [PMID: 32351505 PMCID: PMC7174632 DOI: 10.3389/fimmu.2020.00620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/18/2020] [Indexed: 11/13/2022] Open
Abstract
The occurrence of neutralizing anti-FVIII antibodies is a major complication in the treatment of patients affected by hemophilia A. The immune response to FVIII is a complex, multi-factorial process that has been extensively studied for the past two decades. The reasons why only a proportion of hemophilic patients treated with FVIII concentrates develop a clinically significant immune response is incompletely understood. The "danger theory" has been proposed as a possible explanation to interpret the findings of some observational clinical studies highlighting the possible detrimental impact of inflammatory stimuli at the time of replacement therapy on inhibitor development. The host immune system is often challenged to react to FVIII under steady state or inflammatory conditions (e.g., bleeding, infections) although fine tuning of mechanisms of immune tolerance can control this reactivity and promote long-term unresponsiveness to the therapeutically administered factor. Recent studies have provided evidence that multiple interactions involving central and peripheral mechanisms of tolerance are integrated by the host immune system with the environmental conditions at the time of FVIII exposure and influence the balance between immunity and tolerance to FVIII. Here we review evidences showing the involvement of two key immunoregulatory oxygenase enzymes (IDO1, HO-1) that have been studied in hemophilia patients and pre-clinical models, showing that the ability of the host immune system to induce such regulatory proteins under inflammatory conditions can play important roles in the balance between immunity and tolerance to exogenous FVIII.
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Affiliation(s)
- Davide Matino
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada
| | - Sajjad Afraz
- Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada
| | - George Zhao
- McMaster Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Paul Tieu
- Thrombosis and Atherosclerosis Research Institute, Hamilton, ON, Canada
- McMaster Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Marco Gargaro
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | - Alfonso Iorio
- Department of Health Research Methods, Evidence, and Impact, Hamilton, ON, Canada
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11
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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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12
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Lacroix-Desmazes S, Voorberg J, Lillicrap D, Scott DW, Pratt KP. Tolerating Factor VIII: Recent Progress. Front Immunol 2020; 10:2991. [PMID: 31998296 PMCID: PMC6965068 DOI: 10.3389/fimmu.2019.02991] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 12/05/2019] [Indexed: 02/02/2023] Open
Abstract
Development of neutralizing antibodies against biotherapeutic agents administered to prevent or treat various clinical conditions is a longstanding and growing problem faced by patients, medical providers and pharmaceutical companies. The hemophilia A community has deep experience with attempting to manage such deleterious immune responses, as the lifesaving protein drug factor VIII (FVIII) has been in use for decades. Hemophilia A is a bleeding disorder caused by genetic mutations that result in absent or dysfunctional FVIII. Prophylactic treatment consists of regular intravenous FVIII infusions. Unfortunately, 1/4 to 1/3 of patients develop neutralizing anti-FVIII antibodies, referred to clinically as “inhibitors,” which result in a serious bleeding diathesis. Until recently, the only therapeutic option for these patients was “Immune Tolerance Induction,” consisting of intensive FVIII administration, which is extraordinarily expensive and fails in ~30% of cases. There has been tremendous recent progress in developing novel potential clinical alternatives for the treatment of hemophilia A, ranging from encouraging results of gene therapy trials, to use of other hemostatic agents (either promoting coagulation or slowing down anti-coagulant or fibrinolytic pathways) to “bypass” the need for FVIII or supplement FVIII replacement therapy. Although these approaches are promising, there is widespread agreement that preventing or reversing inhibitors remains a high priority. Risk profiles of novel therapies are still unknown or incomplete, and FVIII will likely continue to be considered the optimal hemostatic agent to support surgery and manage trauma, or to combine with other therapies. We describe here recent exciting studies, most still pre-clinical, that address FVIII immunogenicity and suggest novel interventions to prevent or reverse inhibitor development. Studies of FVIII uptake, processing and presentation on antigen-presenting cells, epitope mapping, and the roles of complement, heme, von Willebrand factor, glycans, and the microbiome in FVIII immunogenicity are elucidating mechanisms of primary and secondary immune responses and suggesting additional novel targets. Promising tolerogenic therapies include development of FVIII-Fc fusion proteins, nanoparticle-based therapies, oral tolerance, and engineering of regulatory or cytotoxic T cells to render them FVIII-specific. Importantly, these studies are highly applicable to other scenarios where establishing immune tolerance to a defined antigen is a clinical priority.
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Affiliation(s)
| | - Jan Voorberg
- Sanquin Research and Landsteiner Laboratory, Department of Molecular and Cellular Hemostasis, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - David Lillicrap
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada
| | - David W Scott
- Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Kathleen P Pratt
- Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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13
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Varthaman A, Lacroix-Desmazes S. Pathogenic immune response to therapeutic factor VIII: exacerbated response or failed induction of tolerance? Haematologica 2018; 104:236-244. [PMID: 30514798 PMCID: PMC6355482 DOI: 10.3324/haematol.2018.206383] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/23/2018] [Indexed: 01/10/2023] Open
Abstract
Therapeutic factor VIII is highly immunogenic. Despite intensive research in the last decades, the reasons why 5-30% of patients with hemophilia A (of all severities) develop inhibitory anti-factor VIII antibodies (inhibitors) following replacement therapy remain an enigma. Under physiological conditions, endogenous factor VIII is recognized by the immune system. Likewise, numerous observations indicate that, in hemophilia A patients without inhibitors, exogenous therapeutic factor VIII is immunologically assessed and tolerated. A large part of the research on the immunogenicity of therapeutic factor VIII is attempting to identify the ‘danger signals’ that act as adjuvants to the deleterious anti-factor VIII immune responses. However, several of the inflammatory assaults concomitant to factor VIII administration initially hypothesized as potential sources of danger signals (e.g., bleeding, infection, and vaccination) have been disproved to be such signals. Conversely, recent evidence suggests that cells from inhibitor-negative patients are able to activate anti-inflammatory and tolerogenic mechanisms required to suppress deleterious immune responses, while cells from inhibitor-positive patients are not. Based on the available observations, we propose a model in which all hemophilia A patients develop anti-factor VIII immune responses during replacement therapy irrespective of associated danger signals. We further postulate that the onset of clinically relevant factor VIII inhibitors results from an inability to develop counteractive tolerogenic responses to exogenous factor VIII rather than from an exacerbated activation of the immune system at the time of factor VIII administration. A better understanding of the pathogenesis of neutralizing anti-factor VIII antibodies will have repercussions on the clinical management of patients and highlight new strategies to achieve active immune tolerance to therapeutic factor VIII.
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Affiliation(s)
- Aditi Varthaman
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, UK.,INSERM, UMR S 1138, Centre de Recherche des Cordeliers, Paris, France.,Sorbonne Université, UMR S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, France
| | - Sébastien Lacroix-Desmazes
- INSERM, UMR S 1138, Centre de Recherche des Cordeliers, Paris, France .,Sorbonne Université, UMR S 1138, Centre de Recherche des Cordeliers, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, UMR S 1138, Centre de Recherche des Cordeliers, France
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14
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CD4 T cells specific for factor VIII are present at high frequency in healthy donors and comprise naïve and memory cells. Blood Adv 2017; 1:1842-1847. [PMID: 29296830 DOI: 10.1182/bloodadvances.2017008706] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/14/2017] [Indexed: 12/20/2022] Open
Abstract
We investigated the frequency and subset origin of circulating factor VIII (FVIII)-specific CD4 T cells in healthy donors. Total CD4 T cells and purified CD4 T-cell subsets were stimulated with FVIII-loaded autologous dendritic cells and challenged for specificity in interferon-γ enzyme-linked immunospots. The number of specific T-cell lines allowed estimation of the frequency of T cells circulating in the blood of the donors. All the 16 healthy donors generated strong in vitro T-cell responses, leading to the generation of 154 FVIII-specific T-cell lines. The mean frequency of FVIII-specific CD4 T cells in healthy donors was similar to that of T cells specific for foreign antigens and greater than that of T cells specific for known immunogenic therapeutic proteins. Normal levels of endogenous FVIII in healthy donors therefore do not prevent a significant escape of FVIII-specific CD4 T cells from negative thymic selection. FVIII-specific T cells mainly originated from both the naïve and central memory cell subsets, but their frequencies remained low as compared with those of cells specific for foreign antigens in immunized donors. The observation of a spontaneous generation of FVIII-specific memory T cells without a global expansion suggests peculiar peripheral tolerance mechanisms to FVIII in healthy donors.
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15
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Lai JD, Lillicrap D. Factor VIII inhibitors: Advances in basic and translational science. Int J Lab Hematol 2017; 39 Suppl 1:6-13. [DOI: 10.1111/ijlh.12659] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/18/2017] [Indexed: 11/27/2022]
Affiliation(s)
- J. D. Lai
- Department of Pathology & Molecular Medicine; Queen's University; Kingston ON Canada
| | - D. Lillicrap
- Department of Pathology & Molecular Medicine; Queen's University; Kingston ON Canada
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16
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Batsuli G, Meeks SL, Herzog RW, Lacroix-Desmazes S. Innovating immune tolerance induction for haemophilia. Haemophilia 2017; 22 Suppl 5:31-5. [PMID: 27405673 DOI: 10.1111/hae.12989] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2016] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Haemophilia A is an X-linked bleeding disorder characterized by a deficiency of coagulation protein factor VIII (FVIII). A challenging complication of therapeutic FVIII infusions is the formation of neutralizing alloantibodies against the FVIII protein defined as inhibitors. The development of FVIII inhibitors drastically alters the quality of life of the patients and is associated with tremendous increases in morbidity as well as treatment costs. AIM Current clinical immune tolerance induction protocols to reverse inhibitors are lengthy, costly and not effective in all patients. Prophylactic protocols to prevent inhibitor formation have not yet been developed in the clinical setting. However, there has been ample progress towards this goal in recent years in preclinical studies using animal models of haemophilia. METHODS Here, we review the mechanisms that lead to inhibitor formation against FVIII and two promising new strategies for antigen-specific tolerance induction. RESULTS CD4+ T cells play an important role in the FVIII-specific B cell response. Immune tolerance can be induced based on transplacental delivery of FVIII domains fused to Fc or on oral delivery of leaf cells from chloroplast transgenic crop plants. CONCLUSIONS Recent literature suggests that prophylactic tolerance induction protocols for FVIII may be feasible in haemophilia A patients.
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Affiliation(s)
- G Batsuli
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University, Atlanta, GA, USA
| | - S L Meeks
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University, Atlanta, GA, USA
| | - R W Herzog
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - S Lacroix-Desmazes
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France
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17
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Diaz I, Bolloré K, Tuaillon E, Lapalud P, Giansily-Blaizot M, Vendrell JP, Schved JF, Lavigne-Lissalde G. Circulating FVIII-specific IgG, IgA and IgM memory B cells from haemophilia A patients. Haemophilia 2016; 22:799-805. [DOI: 10.1111/hae.12958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2016] [Indexed: 01/02/2023]
Affiliation(s)
- I. Diaz
- Laboratory of Hematology; University Hospital of Montpellier; Montpellier France
- Institute of Research in Biotherapy; Montpellier France
| | - K. Bolloré
- Institute of Research in Biotherapy; Montpellier France
- INSERM U1058; Montpellier 1 University; Montpellier France
| | - E. Tuaillon
- Institute of Research in Biotherapy; Montpellier France
- INSERM U1058; Montpellier 1 University; Montpellier France
| | - P. Lapalud
- UMR 3145 SysDiag CNRS/Biorad; Montpellier France
| | | | - J. P. Vendrell
- INSERM U1058; Montpellier 1 University; Montpellier France
| | - J. F. Schved
- Laboratory of Hematology; University Hospital of Montpellier; Montpellier France
- Regional Hemophilia Treatment Center; Montpellier France
| | - G. Lavigne-Lissalde
- UMR 3145 SysDiag CNRS/Biorad; Montpellier France
- Regional Hemophilia Treatment Center; Montpellier France
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18
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Hartholt RB, Peyron I, Voorberg J. Hunting down factor VIII in the immunopeptidome. Cell Immunol 2016; 301:59-64. [DOI: 10.1016/j.cellimm.2015.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/04/2015] [Accepted: 11/04/2015] [Indexed: 01/24/2023]
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19
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Ettinger RA, James EA, Kwok WW, Thompson AR, Pratt KP. HLA-DR-restricted T-cell responses to factor VIII epitopes in a mild haemophilia A family with missense substitution A2201P. Haemophilia 2011; 16:44-55. [PMID: 20536985 DOI: 10.1111/j.1365-2516.2008.01905.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An HLA-DRA-DRB1*0101-restricted T-cell epitope in the factor VIII (FVIII) C2 domain occurred in a mild haemophilia A patient with missense substitution FVIII-A2201P. His T cells responded to synthetic peptides FVIII(2186-2205) and FVIII(2194-2213) (J Thromb Haemost 2007; 5: 2399). T cells from family members with genotype FVIII-A2201P were analysed to determine if FVIII-specific T cells occur in individuals with a haemophilic mutation but no clinically significant inhibitor response. Fluorescent MHC class II tetramers corresponding to subjects'HLA-DRB1 types were loaded with 20-mer peptides and utilized to label antigen-specific CD4+ T cells. T-cell responses to peptides spanning the FVIII-C2 sequence were evaluated. T cells recognizing specific peptides were cloned, and antigen specificity was verified by proliferation assays. Plasma and/or purified IgG samples were tested for FVIII inhibitory activity. CD4+ T cells and T-cell clones from two brothers who shared the DRB1*0101 allele responded to FVIII(2194-2213). A haemophilic cousin's HLA-DRA-DRB1*1104-restricted response to FVIII(2202-2221) was detected only when CD4+CD25+ cells were depleted. A great uncle and two obligate carriers had no detectable FVIII-C2-specific T cells. Concentrated IgG from the brother without a clinical inhibitor response showed a low-titre FVIII inhibitor. FVIII-specific T cells and inhibitory IgG were found in a previously infused, haemophilic subject who had a sub-clinical FVIII inhibitor. CD4+CD25+ depleted T cells from a non-infused haemophilic cousin recognized an overlapping FVIII epitope, indicating a latent HLA-DRA-DRB1*1104-restricted T-cell response to FVIII. Specific T-cell responses to FVIII can occur without clinically significant inhibitors.
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Affiliation(s)
- R A Ettinger
- Puget Sound Blood Center, BRI Rm 3016, 921 Terry Avenue, Seattle, WA 98104, USA
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20
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Chaves DG, Velloso-Rodrigues C, Oliveira CA, Teixeira-Carvalho A, Santoro MM, Martins-Filho OA. A shift towards a T cell cytokine deficiency along with an anti-inflammatory/regulatory microenvironment may enable the synthesis of anti-FVIII inhibitors in haemophilia A patients. Clin Exp Immunol 2010; 162:425-37. [PMID: 20846164 PMCID: PMC3026546 DOI: 10.1111/j.1365-2249.2010.04258.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2010] [Indexed: 11/30/2022] Open
Abstract
Despite the clinical relevance of anti-factor VIII (FVIII) antibodies (anti-FVIII inhibitors) impairing haemostatic activity of haemophilia A (HA) patients, the immunological mechanisms underlying their production are unknown. Aiming to understand more clearly the immune response in patients with [HAα-FVIII(+)] and without [HAα-FVIII(-)] anti-FVIII inhibitors, we have characterized the cytokine pattern of peripheral blood leucocytes, using an in vitro stimulation of whole blood samples with plasma-derived (pFVIII) or recombinant FVIII (rFVIII). The results highlighted decreased levels of tumour necrosis factor (TNF)-α(+) neutrophils with higher interleukin (IL)-5/TNF-α ratio in HAα-FVIII(+). All HA samples displayed decreased levels of IL-10(+) monocytes when compared to the blood donor (BD) samples. HAα-FVIII(+) showed lower levels of TNF-α(+) monocytes and increased IL-10/TNF-α ratio. Analysis of adaptive immunity revealed increased levels of interferon (IFN)-γ(+) , TNF-α(+) and IL-4(+) T-cells, from both CD4(+) and CD8(+) T cells, in HAα-FVIII(-) when compared to BD. Moreover, increased frequency of IL-10(+) B cells and higher levels of α-FVIII IgG1 were observed in HAα-FVIII(-). Basal levels of cytokine(+) B-cells, similar to BD, and higher levels of α-FVIII IgG4 are major features in HAα-FVIII(+). The global cytokine profile demonstrated a major anti-inflammatory/regulatory pattern in HAα-FVIII(+), confirmed by the in vitro stimuli with pFVIII or rFVIII. The polarized anti-inflammatory/regulatory immune response in HAα-FVIII(+) and the mixed pattern with a bias towards an inflammatory cytokine profile, modulated by IL-4 in HAα-FVIII(-), may be the key element to drive the development of distinct subclasses of anti-FVIII antibodies. These finding have implications for the design of safe and effective therapeutic protocols to control inhibitors synthesis in HA patients.
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Affiliation(s)
- D G Chaves
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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21
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Abstract
A large proportion of hemophilia A patients who receive replacement therapy, develop an immune response toward the infused factor VIII (FVIII). In this review, we discuss recent progress in several aspects of the anti-FVIII immune response, focusing on the sites of FVIII endocytosis (marginal zone of the spleen and bleeding site), the type of antigen-presenting cells (dendritic cells, macrophages and B cells) and endocytic receptors, implicated in FVIII presentation to T cells during primary and secondary immune response. Although it is becoming increasingly clear that regulatory T cells are involved in FVIII tolerance in healthy subjects and potentially in patients without inhibitors, we would like to demonstrate that little is known about the different T cells subsets and the cytokines network, which are also crucial for the development of allo- and autoimmune diseases. As more information on these issues becomes available, a better understanding of the role of each immune cells compartment in promoting FVIII tolerance or inhibitors development might lead to new strategies to promote FVIII tolerance in hemophilia A patients.
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22
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Recombinant and plasma-derived factor VIII products induce distinct splenic cytokine microenvironments in hemophilia A mice. Blood 2009; 114:871-80. [DOI: 10.1182/blood-2008-09-174649] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The use of plasma-derived factor VIII (pdFVIII) concentrates in hemophilia A has been reported to result in reduced anti-FVIII antibody formation. In this study, we have investigated whether the cytokine microenvironment induced by pdFVIII has an influence on reducing anti-FVIII antibody titers in hemophilic mice. Microarray and confirmatory quantitative reverse transcription polymerase chain reaction (RT-PCR) experiments show that pdFVIII infusion causes a different transcriptional profile in dendritic cells than recombinant FVIII (rFVIII). Both treatments caused up-regulation of proinflammatory gene expression, but rFVIII and pdFVIII treatments promote expression of genes that induce Th1 and Th2 responses, respectively. Moreover, administration of rFVIII or pdFVIII concentrates resulted in distinct T-cell splenic cytokine microenvironments. rFVIII induced the release of Th1 cytokines and IL-10, whereas pdFVIII induced the release of Th2 cytokines and transforming growth factor-β. We have also observed high titers of anti–human von Willebrand factor (VWF) antibodies in the pdFVIII-treated mice and propose that this results from antigenic competition. We further investigated the role of this phenomenon using infusions of FVIII and increasing concentrations of recombinant human factor IX (FIX). These studies show an inverse relationship between increasing concentrations of FIX and the production of anti-FVIII antibodies. In summary, these studies report new mechanisms that contribute to reduced anti-FVIII antibody development in hemophilia A after pdFVIII infusions.
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23
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Pratt KP, Thompson AR. B-Cell and T-Cell Epitopes in Anti-factor VIII Immune Responses. Clin Rev Allergy Immunol 2009; 37:80-95. [DOI: 10.1007/s12016-009-8120-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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24
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Abstract
The presence of antibodies (Abs) in hemophilia A patients can potentially influence the therapeutic qualities of factor VIII (fVIII) administration. Much work has been focused on the presence of inhibitory antibodies, whereas the quantitation of noninhibitory anti-fVIII antibodies has been largely undetermined. Our objective was to develop a sensitive and specific fluorescence-based immunoassay (FLI) for the quantitation of anti-fVIIIAbs in human plasma. Affinity-purified human anti-fVIIIAb, isolated from a hemophilia A subject, was used as a calibrator with a detectability limit of 40 (+/-1.5) pM. The calibrator and the human plasma anti-fVIIIAb were captured on recombinant fVIII (rfVIII)- coupled microspheres and probed with mouse anti-human Ig-R-phycoerythrin. Plasma samples from 150 healthy donors and 39 inhibitor-negative hemophilia A subjects were compared with 4 inhibitor-positive hemophilia A plasma samples with inhibitor titers of 1 BU/mL (94.6 +/- 0.8 nM), 11 BU/mL (214.3 +/- 7.1 nM), 106 BU/mL (2209.4 +/- 84.9 nM), 140 BU/mL (2417.7 +/- 3.8 nM) as measured by the Nijmegen method. We also describe the validation of a mouse anti-human fVIIIAb as a surrogate calibrator. Four healthy individuals (3%) showed detectable anti-fVIIIAb in the range of 0.6 to 6.2 nM, whereas 13 (33%) of the 39 inhibitor-free hemophilia A subjects were positive for anti-fVIIIAb in the range of 0.5 to 20 nM. The method may be useful for therapeutic management of hemophilia A patients.
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25
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Abstract
Procoagulant factor VIII (FVIII) is either produced endogenously under physiologic conditions, or administered exogenously as a therapeutic hemostatic drug in patients with hemophilia A. In the circulation, FVIII interacts with a multitude of glycoproteins, and may be used for coagulation at the sites of bleeding, eliminated by scavenger cells, or processed by the immune system, either as a self-constituent or as a foreign antigen. The fate of FVIII is dictated by the immune status of the individual, the location of FVIII in the body at a given time point, and the inflammatory microenvironment. It also depends on the local concentration of FVIII and of each interacting partner, and on the affinity of the respective interactions. FVIII, by virtue of its promiscuity, thus constitutes the core of a dynamic network that links the coagulation cascade, cells of the immune system, and, presumably, the inflammatory compartment. We describe the different interactions that FVIII is prone to establish during its life cycle, with a special focus on players of the innate and adaptive immune response. Lessons can be learned from understanding the dynamics of FVIII interactions--lessons that should pave the way to the conception of long-lasting hemostatic drugs devoid of iatrogenic immunogenicity.
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26
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James EA, Kwok WW, Ettinger RA, Thompson AR, Pratt KP. T-cell responses over time in a mild hemophilia A inhibitor subject: epitope identification and transient immunogenicity of the corresponding self-peptide. J Thromb Haemost 2007; 5:2399-407. [PMID: 18034765 DOI: 10.1111/j.1538-7836.2007.02762.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Antibodies that neutralize factor (F) VIII activity, clinically referred to as 'inhibitors', complicate the treatment of hemophilia A patients; current tolerance and bypass strategies are extremely costly and sometimes ineffective. The development of inhibitors requires T-cell help. OBJECTIVES We characterized T-cell responses of a subject with mild hemophilia A with missense genotype A2201P for one year following his initial inhibitor response, with the goals of defining the primary epitope(s) and its (their) MHC Class II restriction. We investigated the possible involvement of regulatory T cells in modulating immune responses. PATIENTS/METHODS The subject developed high-titer FVIII-neutralizing antibodies (250 BU mL(-1)) that declined over time to 8 BU ml(-1). His clotting activity was initially impaired (3%) but returned to baseline (8-10%) within four weeks. MHC Class II tetramers were used to analyze his CD4 T cells, which were stimulated with peptides spanning the C2 domain. Responses of total and CD25-depleted CD4 cells to sequences containing A2201 (native), P2201 (hemophilic), and other predicted T-cell epitopes were evaluated. RESULTS AND CONCLUSIONS An HLA-DRA-DRB1*0101 restricted T-cell epitope containing the wild-type A2201 sequence was identified. Interestingly, peptides containing A2201 were recognized by CD4 T cells at all time points, whereas a P2201 peptide was recognized only near the initial peak response. The responsiveness of CD25-depleted CD4 cells to an A2201 peptide was enhanced 11 and 19 weeks following inhibitor detection, suggesting the possible involvement of CD4+CD25+ regulatory T cells in modulating immune responses. Patient-derived T-cell clones proliferated in response to C2 protein and to peptides containing A2201 but not P2201.
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Affiliation(s)
- E A James
- Benaroya Research Institute, Seattle, WA 98104, USA
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27
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Dasgupta S, Navarrete AM, Delignat S, Wootla B, Andre S, Nagaraja V, Lacroix-Desmazes S, Kaveri SV. Immune response against therapeutic factor VIII in hemophilia A patients—A survey of probable risk factors. Immunol Lett 2007; 110:23-8. [PMID: 17467813 DOI: 10.1016/j.imlet.2007.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 03/22/2007] [Indexed: 11/26/2022]
Abstract
A number of diseases are treated by passive administration of human proteins. Human coagulation factor VIII (FVIII) is one such protein which is administered to hemophilia A patients in order to manage and treat hemorrhagic incidences. This mode of therapy suffers from the side effect of generating anti-FVIII antibodies (inhibitors) which neutralizes the function of the infused FVIII. At a time when efficient viral screening procedures are at place, development of inhibitors poses the greatest threat to such a therapy. Various predisposing factors, both patient and product-related, are responsible for the development of inhibitory antibodies. A proper understanding of these "risk-factors" would eventually help to better design therapeutic regimen to tackle hemophilia A.
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28
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Astermark J. Why do inhibitors develop? Principles of and factors influencing the risk for inhibitor development in haemophilia. Haemophilia 2006; 12 Suppl 3:52-60. [PMID: 16683997 DOI: 10.1111/j.1365-2516.2006.01261.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The formation of inhibitory alloantibodies is, in the postinfectious era, the most severe and costly complication of replacement therapy in patients with haemophilia. The complexity of the immune response to the infused factor becomes more and more obvious as knowledge in the area increases. Antibodies develop as a result of a complex multi-factorial interaction between antigen-presenting cells, T- and B-lymphocytes. Genetic susceptibility of cell surface molecules, such as the major histocompatibility complex, the T-cell receptor and cytokine receptors, as well as various immunomodulatory molecules have a major impact on the outcome. In addition, environmental factors probably influence the risk of inhibitor development. The current concept of inhibitor development is reviewed. A better understanding of the pathophysiological mechanisms involved will facilitate improvement of therapy in the future, and hopefully provide an opportunity to prevent this complication of treatment.
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Affiliation(s)
- J Astermark
- Department for Coagulation Disorders, Malmö University Hospital, Malmö, Sweden.
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29
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Sakai M, Shima M, Shirahata A. Successful steroid pulse treatment in childhood acquired haemophilia with nephrotic syndrome. Haemophilia 2005; 11:285-9. [PMID: 15876276 DOI: 10.1111/j.1365-2516.2005.01093.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We encountered a 2-year-old boy with acquired haemophilia, which rarely occurs in children, who was complicated with nephrotic syndrome. In mid-August 2001, he was diagnosed to have nephrotic syndrome based on the presence of massive proteinuria and hypoalbuminaemia. Activated partial thromboplastin time (APTT) was normal at 42.4 s at that time. After starting prednisone administration of 2 mg kg(-1) day(-1), the proteinuria disappeared immediately. However, in early October the same year, subcutaneous ecchymosis and intramuscular bleeding occurred for no apparent reason, and from the examination results his APTT was 106.4 s, factor VIII (FVIII) activity was <1%, and the anti-FVIII inhibitor titre was 6.9 BU ml(-1). As a result, he was diagnosed to have acquired haemophilia. The anti-nuclear antibody and anti-phospholipid antibody were negative. With recombinant activated FVII, haemostasis was obtained, and after administering three courses of steroid pulse therapy (methyl prednisolone: 20 mg kg(-1) day(-1) x 3 days), the anti-FVIII inhibitory activity disappeared. An analysis of the immunological and coagulation properties of his FVIII autoantibodies showed the anti-FVIII inhibitory activity to be mediated by IgG(1) antibody. In other words, his FVIII inhibitor was a Th1 dominant and it provided a good response to treatment. These findings correlate with those of previous reports. The patient thereafter frequently demonstrated a recurrence of nephrotic syndrome. As a result, he is presently being managed with cyclosporine. However, no recurrence of the anti-FVIII titre has been observed.
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Affiliation(s)
- M Sakai
- Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
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30
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Jones TD, Phillips WJ, Smith BJ, Bamford CA, Nayee PD, Baglin TP, Gaston JSH, Baker MP. Identification and removal of a promiscuous CD4+ T cell epitope from the C1 domain of factor VIII. J Thromb Haemost 2005; 3:991-1000. [PMID: 15869596 DOI: 10.1111/j.1538-7836.2005.01309.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND The development of inhibitors in hemophiliacs is a severe complication of factor VIII (FVIII) replacement therapy and is a process driven by FVIII specific T helper cells. OBJECTIVES To finely map T cell epitopes within the whole FVIII protein in order to investigate the possibility of engineering FVIII variants with reduced propensity for inhibitor development. PATIENTS AND METHODS T cell lines were generated from five patients with severe hemophilia who had developed inhibitors, and were screened for T cell proliferation against pools of overlapping peptides spanning the entire B domain deleted (BDD) FVIII sequence. Positive peptide pools were decoded by screening individual peptides against the T cell lines. Positive peptides, and mutants thereof, were tested for their ability to bind major histocompatibility complex (MHC) Class II and stimulate T cell proliferation in a panel of healthy donors. The activities of the corresponding mutant proteins were assessed via chromogenic assay. RESULTS One peptide, spanning FVIII amino acids 2098-2112, elicited a vigorous response from one hemophiliac donor, induced strong T cell responses in the panel of healthy donors and bound to a number of HLA-DR alleles. Mutations were made in this peptide that removed its ability to stimulate T cells of healthy donors and to bind to MHC Class II while retaining full activity when incorporated into a mutant BDD-FVIII protein. CONCLUSIONS Fine T cell epitope mapping of the entire FVIII protein is feasible, although challenging, and this knowledge may be used to create FVIII variants which potentially have reduced immunogenicity.
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Affiliation(s)
- T D Jones
- Biovation Ltd, Babraham, Cambridge, UK.
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31
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Hu GL, Okita DK, Conti-Fine BM. T cell recognition of the A2 domain of coagulation factor VIII in hemophilia patients and healthy subjects. J Thromb Haemost 2004; 2:1908-17. [PMID: 15550021 DOI: 10.1111/j.1538-7836.2004.00918.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hemophilia A patients treated with coagulation factor VIII (FVIII), and also some healthy subjects, may develop anti-FVIII antibodies (Ab), whose synthesis is driven by FVIII-specific CD4+ T cells. Some Ab block the procoagulant function of FVIII (inhibitors). Many inhibitors recognize epitopes on the FVIII A2 domain. Here, we have sought to identify A2 epitopes recognized by CD4+ T cells. We tested the proliferative response of CD4+ blood lymphocytes (BL) from hemophilia patients and healthy subjects, to overlapping synthetic peptides spanning the A2 domain sequence. Many A2 peptides induced proliferative responses of CD4+ BL from one or more subjects. The peptide-induced responses were strongest in hemophilia patients with inhibitors, weakest in healthy subjects. A2 peptides comprising residues 371-400, 621-650 and 671-690 elicited frequent and strong responses in hemophilia A patients, and especially in those with inhibitors. Healthy subjects recognized frequently only the sequence 371-400. A three-dimensional model of the A2 domain suggests that these CD4+ epitope sequences have structural features typical of 'universal' CD4+ T epitopes.
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Affiliation(s)
- G-L Hu
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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32
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Abstract
PURPOSE OF REVIEW The development of an inhibitory response to factor VIII (FVIII) remains a puzzling challenge both for clinicians and scientists, not to mention the difficulties of maintaining hemostasis in patients producing inhibitors. RECENT FINDINGS Three main research lines have been explored in recent months. The mechanisms by which an anti-FVIII antibody response is elicited in patients has been examined at both the B- and T-cell levels, with particular emphasis on the generation of specific B- and T-cell clones. The hemophilia A mouse model has served to confirm the main characteristics of the anti-FVIII immune response in terms of T-cell dependency and memorization of the response. Novel strategies for the prevention and downregulation of inhibitors have emerged, with special interest in antigen-specific approaches. SUMMARY Although the ultimate goal, preventing or suppressing inhibitor formation in patients, is not yet achieved, the research activity developed over the past months brings us forward in that direction.
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Affiliation(s)
- Marc G Jacquemin
- Center for Molecular and Vascular Biology, University of Leuven, Campus Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
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