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Zerra PE, Parker ET, Baldwin WH, Healey JF, Patel SR, McCoy JW, Cox C, Stowell SR, Meeks SL. Engineering a Therapeutic Protein to Enhance the Study of Anti-Drug Immunity. Biomedicines 2022; 10:1724. [PMID: 35885029 PMCID: PMC9313379 DOI: 10.3390/biomedicines10071724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/29/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
The development of anti-drug antibodies represents a significant barrier to the utilization of protein-based therapies for a wide variety of diseases. While the rate of antibody formation can vary depending on the therapeutic employed and the target patient population receiving the drug, the antigen-specific immune response underlying the development of anti-drug antibodies often remains difficult to define. This is especially true for patients with hemophilia A who, following exposure, develop antibodies against the coagulation factor, factor VIII (FVIII). Models capable of studying this response in an antigen-specific manner have been lacking. To overcome this challenge, we engineered FVIII to contain a peptide (323-339) from the model antigen ovalbumin (OVA), a very common tool used to study antigen-specific immunity. FVIII with an OVA peptide (FVIII-OVA) retained clotting activity and possessed the ability to activate CD4 T cells specific to OVA323-339 in vitro. When compared to FVIII alone, FVIII-OVA also exhibited a similar level of immunogenicity, suggesting that the presence of OVA323-339 does not substantially alter the anti-FVIII immune response. Intriguingly, while little CD4 T cell response could be observed following exposure to FVIII-OVA alone, inclusion of anti-FVIII antibodies, recently shown to favorably modulate anti-FVIII immune responses, significantly enhanced CD4 T cell activation following FVIII-OVA exposure. These results demonstrate that model antigens can be incorporated into a therapeutic protein to study antigen-specific responses and more specifically that the CD4 T cell response to FVIII-OVA can be augmented by pre-existing anti-FVIII antibodies.
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Affiliation(s)
- Patricia E. Zerra
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University, Atlanta, GA 30322, USA; (P.E.Z.); (J.W.M.)
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Ernest T. Parker
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Wallace Hunter Baldwin
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - John F. Healey
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Seema R. Patel
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - James W. McCoy
- Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University, Atlanta, GA 30322, USA; (P.E.Z.); (J.W.M.)
| | - Courtney Cox
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
| | - Sean R. Stowell
- Joint Program in Transfusion Medicine, Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Shannon L. Meeks
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, GA 30322, USA; (E.T.P.); (W.H.B.); (J.F.H.); (S.R.P.); (C.C.)
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Patel SR, Lundgren TS, Baldwin WH, Cox C, Parker ET, Healey JF, Jajosky RP, Zerra PE, Josephson CD, Doering CB, Stowell SR, Meeks SL. Neutralizing Antibodies Against Factor VIII Can Occur Through a Non-Germinal Center Pathway. Front Immunol 2022; 13:880829. [PMID: 35634288 PMCID: PMC9132091 DOI: 10.3389/fimmu.2022.880829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Humoral immunity to factor VIII (FVIII) represents a significant challenge for the treatment of patients with hemophilia A. Current paradigms indicate that neutralizing antibodies against FVIII (inhibitors) occur through a classical CD4 T cell, germinal center (GC) dependent process. However, clinical observations suggest that the nature of the immune response to FVIII may differ between patients. While some patients produce persistent low or high inhibitor titers, others generate a transient response. Moreover, FVIII reactive memory B cells are only detectable in some patients with sustained inhibitor titers. The determinants regulating the type of immune response a patient develops, let alone how the immune response differs in these patients remains incompletely understood. One hypothesis is that polymorphisms within immunoregulatory genes alter the underlying immune response to FVIII, and thereby the inhibitor response. Consistent with this, studies report that inhibitor titers to FVIII differ in animals with the same F8 pathogenic variant but completely distinct backgrounds; though, how these genetic disparities affect the immune response to FVIII remains to be investigated. Given this, we sought to mechanistically dissect how genetics impact the underlying immune response to FVIII. In particular, as the risk of producing inhibitors is weakly associated with differences in HLA, we hypothesized that genetic factors other than HLA influence the immune response to FVIII and downstream inhibitor formation. Our data demonstrate that FVIII deficient mice encoding the same MHC and F8 variant produce disparate inhibitor titers, and that the type of inhibitor response formed associates with the ability to generate GCs. Interestingly, the formation of antibodies through a GC or non-GC pathway does not appear to be due to differences in CD4 T cell immunity, as the CD4 T cell response to an immunodominant epitope in FVIII was similar in these mice. These results indicate that genetics can impact the process by which inhibitors develop and may in part explain the apparent propensity of patients to form distinct inhibitor responses. Moreover, these data highlight an underappreciated immunological pathway of humoral immunity to FVIII and lay the groundwork for identification of biomarkers for the development of approaches to tolerize against FVIII.
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Affiliation(s)
- Seema R Patel
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Taran S Lundgren
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States.,Graduate Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University School of Medicine, Atlanta, GA, United States
| | - Wallace Hunter Baldwin
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Courtney Cox
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Ernest T Parker
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - John F Healey
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Ryan P Jajosky
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Patricia E Zerra
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States.,Center for Transfusion Medicine and Cellular Therapies, Department of Laboratory Medicine and Pathology, Emory University School of Medicine, Atlanta, GA, United States
| | - Cassandra D Josephson
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Christopher B Doering
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
| | - Sean R Stowell
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Shannon L Meeks
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, United States
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Ito J, Baldwin WH, Cox C, Healey JF, Parker ET, Legan ER, Li R, Gill S, Batsuli G. Removal of single-site N-linked glycans on factor VIII alters binding of domain-specific monoclonal antibodies. J Thromb Haemost 2022; 20:574-588. [PMID: 34863021 PMCID: PMC8885965 DOI: 10.1111/jth.15616] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 11/16/2021] [Accepted: 12/01/2021] [Indexed: 01/10/2023]
Abstract
BACKGROUND A portion of individuals with hemophilia A develop neutralizing antibodies called inhibitors to glycoprotein factor VIII (FVIII). There are multiple risk factors that contribute to the risk of inhibitor formation. However, knowledge of the role of FVIII asparagine (N)-linked glycosylation in FVIII immunity is limited. OBJECTIVE To evaluate the effect of site-specific N-linked glycan removal on FVIII biochemical properties, endocytosis by murine bone marrow-derived dendritic cells (BMDCs), and antibody responses. METHODS Four recombinant B domain-deleted (BDD) FVIII variants with single-site amino acid substitutions to remove N-linked glycans were produced for experimental assays. RESULTS BDD FVIII-N41G, FVIII-N239A, FVIII-N1810A, and FVIII-N2118A with confirmed removal of N-linked glycans and similar glycosylation profiles to BDD FVIII were produced. There were no differences in thrombin activation or von Willebrand factor binding of FVIII variants compared with BDD FVIII; however, reduced FVIII expression, activity, and specific activity was observed with all variants. BDD FVIII-N41G and FVIII-N1810A had reduced uptake by BMDCs, but there were no differences in antibody development in immunized hemophilia A mice compared with BDD FVIII. Half of a repertoire of 12 domain-specific FVIII MAbs had significantly reduced binding to ≥1 FVIII variant with a 50% decrease in A1 domain MAb 2-116 binding to FVIII-N239A. CONCLUSIONS Modifications of FVIII N-linked glycans reduced FVIII endocytosis by BMDCs and binding of domain-specific FVIII MAbs, but did not alter de novo antibody production in hemophilia A mice, suggesting that N-glycans do not significantly contribute to inhibitor formation.
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Affiliation(s)
- Jasmine Ito
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Wallace Hunter Baldwin
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Courtney Cox
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - John F Healey
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Ernest T Parker
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Emily R Legan
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Surinder Gill
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Glaivy Batsuli
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta and Department of Pediatrics, Emory University, Atlanta, Georgia, USA
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Batsuli G, Ito J, Mercer R, Baldwin WH, Cox C, Parker ET, Healey JF, Lollar P, Meeks SL. Anti-C1 domain antibodies that accelerate factor VIII clearance contribute to antibody pathogenicity in a murine hemophilia A model. J Thromb Haemost 2018; 16:1779-1788. [PMID: 29981270 PMCID: PMC6123829 DOI: 10.1111/jth.14233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Indexed: 01/06/2023]
Abstract
Essentials Inhibitor formation remains a challenging complication of hemophilia A care. The Bethesda assay is the primary method used for determining bleeding risk and management. Antibodies that block factor VIII binding to von Willebrand factor can increase FVIII clearance. Antibodies that increase clearance contribute to antibody pathogenicity. SUMMARY Background The development of neutralizing anti-factor VIII (FVIII) antibodies remains a challenging complication of modern hemophilia A care. In vitro assays are the primary method used for quantifying inhibitor titers, predicting bleeding risk, and determining bleeding management. However, other mechanisms of inhibition are not accounted for in these assays, which may result in discrepancies between the inhibitor titer and clinical bleeding symptoms. Objectives To evaluate FVIII clearance in vivo as a potential mechanism for antibody pathogenicity and to determine whether increased FVIII dosing regimens correct the associated bleeding phenotype. Methods FVIII-/- or FVIII-/- /von Willebrand factor (VWF)-/- mice were infused with anti-FVIII mAbs directed against the FVIII C1, C2 or A2 domains, followed by infusion of FVIII. Blood loss via the tail snip bleeding model, FVIII activity and FVIII antigen levels were subsequently measured. Results Pathogenic anti-C1 mAbs that compete with VWF for FVIII binding increased the clearance of FVIII-mAb complexes in FVIII-/- mice but not in FVIII-/- /VWF-/- mice. Additionally, pathogenic anti-C2 mAbs that inhibit FVIII binding to VWF increased FVIII clearance in FVIII-/- mice. Anti-C1, anti-C2 and anti-A2 mAbs that do not inhibit VWF binding did not accelerate FVIII clearance. Infusion of increased doses of FVIII in the presence of anti-C1 mAbs partially corrected blood loss in FVIII-/- mice. Conclusions A subset of antibodies that inhibit VWF binding to FVIII increase the clearance of FVIII-mAb complexes, which contributes to antibody pathogenicity. This may explain differences in the bleeding phenotype observed despite factor replacement in some patients with hemophilia A and low-titer inhibitors.
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MESH Headings
- Animals
- Antibodies, Heterophile/administration & dosage
- Antibodies, Heterophile/immunology
- Antibodies, Heterophile/toxicity
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/toxicity
- Antibodies, Neutralizing/administration & dosage
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/toxicity
- Epitopes/immunology
- Factor VIII/antagonists & inhibitors
- Factor VIII/immunology
- Factor VIII/pharmacokinetics
- Hemophilia A/drug therapy
- Hemophilia A/immunology
- Hemorrhage/etiology
- Inhibitory Concentration 50
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Models, Animal
- Phenotype
- Protein Domains
- von Willebrand Diseases
- von Willebrand Factor/metabolism
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Affiliation(s)
- G Batsuli
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - J Ito
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - R Mercer
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - W H Baldwin
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - C Cox
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - E T Parker
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - J F Healey
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - P Lollar
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
| | - S L Meeks
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University, Atlanta, GA, USA
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Baldwin WH, Nord CW. Delayed childbearing in the U.S.: facts and fictions. Popul Bull 1984; 39:1-42. [PMID: 12313332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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Baldwin WH. Adolescent pregnancy and childbearing - growing concerns for Americans. Popul Bull 1976; 31:1-36. [PMID: 12258970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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Baldwin WH, Pitt Ford TR. Modernism and contraceptive use in Colombia. Stud Fam Plann 1976; 7:75-9. [PMID: 1273911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This analysis addresses the question of whether fertility can be lowered without the prior occurrence of the social and economic changes that have come to be labeled modernization. The data show that there exists in Colombia a relatively high level of motivation to control fertility that, for many women, is not coupled with both knowledge of and access to a method of contraception. For the "traditional" woman, the problem may not be lack of motivation so much as lack of access to methods that she is aware of, such as the pill, and lack of knowledge of methods that require few resources of supplies, such as rhythm and withdrawal.
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