1
|
Nguyen TH, Xu Y, Brandt S, Mandelkow M, Raschke R, Strobel U, Delcea M, Zhou W, Liu J, Greinacher A. Characterization of the interaction between platelet factor 4 and homogeneous synthetic low molecular weight heparins. J Thromb Haemost 2020; 18:390-398. [PMID: 31573759 PMCID: PMC7236814 DOI: 10.1111/jth.14657] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/25/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND Heparins are usually produced from animal tissues. It is now possible to synthesize heparins. This provides the abilities to overcome shortages of heparin, to optimize biological effects, and to reduce adverse drug effects. Heparins interact with platelet factor 4 (PF4), which can induce an immune response causing thrombocytopenia. This side effect is called heparin-induced thrombocytopenia (HIT). We characterized the interaction of PF4 and HIT antibodies with oligosaccharides of 6-, 8-, 10-, and 12-mer size and a hypersulfated 12-mer (S12-mer). METHODS We utilized multiple methodologies including isothermal calorimetry, circular dichroism spectroscopy, single molecule force spectroscopy (SMFS), enzyme immunosorbent assay (EIA), and platelet aggregation test to characterize the interaction of synthetic heparin analogs with PF4 and anti-PF4/heparin antibodies. RESULTS The synthetic heparin-like compounds display stronger binding characteristics to PF4 than animal-derived heparins of corresponding lengths. Upon complexation with PF4, 6-mer and S12-mer heparins showed much lower enthalpy, induced less conformational changes in PF4, and interacted with weaker forces than 8-, 10-, and 12-mer heparins. Anti-PF4/heparin antibodies bind more weakly to complexes formed between PF4 and heparins ≤ 8-mer than with complexes formed between PF4 and heparins ≥ 10-mer. Addition of one sulfate group to the 12-mer resulted in a S12-mer, which showed substantial changes in its binding characteristics to PF4. CONCLUSIONS We provide a template for characterizing interactions of newly developed heparin-based anticoagulant drugs with proteins, especially PF4 and the resulting potential antigenicity.
Collapse
Affiliation(s)
- Thi-Huong Nguyen
- institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
- Institute for Bioprocessing and Analytical Measurement Techniques, Heiligenstadt, Germany
- ZIK HIKE—Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University Greifswald, Greifswald, Germany
| | - Yongmei Xu
- Division of Chemical Biology and Medicinal Chemistry, School of Pharmacy, University of North Carolina, Eshelman, Chapel Hill, NC, USA
| | - Sven Brandt
- ZIK HIKE—Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University Greifswald, Greifswald, Germany
| | - Martin Mandelkow
- ZIK HIKE—Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University Greifswald, Greifswald, Germany
| | - Ricarda Raschke
- institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Ulrike Strobel
- institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Mihaela Delcea
- ZIK HIKE—Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University Greifswald, Greifswald, Germany
- Division of Chemical Biology and Medicinal Chemistry, School of Pharmacy, University of North Carolina, Eshelman, Chapel Hill, NC, USA
| | - Wen Zhou
- Institute of Biochemistry, University Greifswald, Greifswald, Germany
| | - Jian Liu
- Institute of Biochemistry, University Greifswald, Greifswald, Germany
| | - Andreas Greinacher
- institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| |
Collapse
|
2
|
Nguyen TH, Greinacher A. Distinct Binding Characteristics of Pathogenic Anti-Platelet Factor-4/Polyanion Antibodies to Antigens Coated on Different Substrates: A Perspective on Clinical Application. ACS NANO 2018; 12:12030-12041. [PMID: 30540167 DOI: 10.1021/acsnano.8b04487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The polyanion heparin, which is frequently used in patients, complexes with the platelet-derived cationic chemokine platelet factor (PF4, CXCL4). This results in the formation of anti-PF4/heparin antibodies (anti-PF4/H Abs). Anti-PF4/H Abs are classified into three groups: (i) nonpathogenic Abs (group 1) with no clinical relevance; (ii) pathogenic heparin-dependent Abs (group 2), which activate platelets and can cause the severe adverse drug effect heparin-induced thrombocytopenia (HIT); and (iii) pathogenic autoimmune-HIT Abs (group 3), in which group 3 anti-PF4/H Abs causes a HIT-like autoimmune disease in the absence of heparin. Enzyme immunoassays using PF4/H complexes coated on the solid phase for detection of anti-PF4/H Abs cannot differentiate between pathogenic and nonpathogenic anti-PF4/H Abs. By single-molecule force spectroscopy, we identify a specific feature of pathogenic group 2 and group 3 Abs antibodies that (in contrast to nonpathogenic group 1 Abs) their binding forces to PF4/H complexes coated on platelets were significantly higher compared with those of PF4/H complexes immobilized on a solid phase. Only group 3 Abs showed high binding forces to platelets without the addition of PF4. In the presence of 50 μg/mL PF4, group 2 Abs also showed high binding forces to platelets. In contrast, binding forces of group 1 Abs always remained low (<100 pN). Our findings may have major relevance for the development of clinically applicable solid-phase assays, which allow differentiation of pathogenic platelet-activating from nonpathogenic anti-PF4/H Abs. Membrane-based expression of antigens might also increase the specificity of other assays for the detection of pathogenic (auto)-antibodies in clinical medicine.
Collapse
Affiliation(s)
- Thi-Huong Nguyen
- Institute for Immunology and Transfusion Medicine , University Medicine Greifswald , 17475 Greifswald , Germany
- ZIK HIKE - Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases , University of Greifswald , 17489 Greifswald , Germany
| | - Andreas Greinacher
- Institute for Immunology and Transfusion Medicine , University Medicine Greifswald , 17475 Greifswald , Germany
| |
Collapse
|
3
|
Bui VC, Nguyen TH. The Role of Single-Molecule Force Spectroscopy in Unraveling Typical and Autoimmune Heparin-induced Thrombocytopenia. Int J Mol Sci 2018; 19:E1054. [PMID: 29614814 PMCID: PMC5979551 DOI: 10.3390/ijms19041054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 03/26/2018] [Accepted: 03/31/2018] [Indexed: 02/07/2023] Open
Abstract
For the last two decades, heparins have been widely used as anticoagulants. Besides numerous advantages, up to 5% patients with heparin administration suffer from a major adverse drug effect known as heparin-induced thrombocytopenia (HIT). This typical HIT can result in deep vein thrombosis, pulmonary embolism, occlusion of a limb artery, acute myocardial infarct, stroke, and a systemic reaction or skin necrosis. The basis of HIT may lead to clinical insights. Recent studies using single-molecule force spectroscopy (SMFS)-based atomic force microscopy revealed detailed binding mechanisms of the interactions between platelet factor 4 (PF4) and heparins of different lengths in typical HIT. Especially, SMFS results allowed identifying a new mechanism of the autoimmune HIT caused by a subset of human-derived antibodies in patients without heparin exposure. The findings proved that not only heparin but also a subset of antibodies induce thrombocytopenia. In this review, the role of SMFS in unraveling a major adverse drug effect and insights into molecular mechanisms inducing thrombocytopenia by both heparins and antibodies will be discussed.
Collapse
Affiliation(s)
- Van-Chien Bui
- Institute for Immunology and Transfusion Medicine, University Medicine of Greifswald, 17475 Greifswald, Germany.
| | - Thi-Huong Nguyen
- Institute for Immunology and Transfusion Medicine, University Medicine of Greifswald, 17475 Greifswald, Germany.
- ZIK HIKE-Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular, 17489 Greifswald, Germany.
| |
Collapse
|
4
|
Delcea M, Greinacher A. Biophysical tools to assess the interaction of PF4 with polyanions. Thromb Haemost 2017; 116:783-791. [DOI: 10.1160/th16-04-0258] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 09/07/2016] [Indexed: 11/05/2022]
Abstract
SummaryThe antigen in heparin-induced thrombocytopenia (HIT) is expressed on platelet factor 4 (PF4) when PF4 complexes with polyanions. In recent years, biophysical tools (e. g. circular dichroism spectroscopy, atomic force microscopy, isothermal titration calorimetry, x-ray crystallography, electron microscopy) have gained an important role to complement immunological and functional assays for better understanding the interaction of heparin with PF4. This allowed identification of those features that make PF4 immunogenic (e. g. a certain conformational change induced by the polyanion, a threshold energy of the complexes, the existence of multimeric complexes, a certain number of bonds formed by PF4 with the polyanion) and to characterize the morphology and thermal stability of complexes formed by the protein with polyanions. These findings and methods can now be applied to test new drugs for their potential to induce the HIT-like adverse drug effect by preclinical in vitro testing. The methods and techniques applied to characterize the antigen in HIT may also be helpful to better understand the mechanisms underlying other antibody-mediated disorders in thrombosis and hemostasis (e. g. acquired hemophilia, thrombotic thrombocytopenic purpura). Furthermore, understanding the mechanisms making the endogenous protein PF4 immunogenic may help to understand the mechanisms underlying other autoimmune disorders.
Collapse
|
5
|
Cámara CI, Wilke N. Interaction of dextran derivatives with lipid monolayers and the consequential modulation of the film properties. Chem Phys Lipids 2017; 204:34-42. [DOI: 10.1016/j.chemphyslip.2017.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 12/23/2022]
|
6
|
Pirrotta A, De Vico L, Solomon GC, Franco I. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes. J Chem Phys 2017. [DOI: 10.1063/1.4976626] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alessandro Pirrotta
- Nano-Science Center and Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Luca De Vico
- Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Gemma C. Solomon
- Nano-Science Center and Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | - Ignacio Franco
- Departments of Chemistry and Physics, University of Rochester, Rochester, New York 14627-0216, USA
| |
Collapse
|
7
|
Nguyen TH. Single-molecule force spectroscopy applied to heparin-induced thrombocytopenia. J Mol Recognit 2016; 30. [PMID: 27790761 DOI: 10.1002/jmr.2585] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 01/01/2023]
Abstract
Heparin-induced thrombocytopenia (HIT), occurring up to approximately 1% to 5% of patients receiving the antithrombotic drug heparins, has a complex pathogenesis involving multiple partners ranging from small molecules to cells/platelets. Recently, insights into the mechanism of HIT have been achieved by using single-molecule force spectroscopy (SMFS), a methodology that allows direct measurements of interactions among HIT partners. Here, the potential of SMFS in unraveling the mechanism of the initial steps in the pathogenesis of HIT at single-molecule resolution is highlighted. The new findings ranging from the molecular binding strengths and kinetics to the determination of the boundary between risk and non-risk heparin drugs or platelet-surface and platelet-platelet interactions will be reviewed. These novel results together have contributed to elucidate the mechanisms underlying HIT and demonstrate how SMFS can be applied to develop safer drugs with a reduced risk profile.
Collapse
Affiliation(s)
- Thi-Huong Nguyen
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, 17475, Greifswald, Germany.,ZIK HIKE - Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University of Greifswald, 17489, Greifswald, Germany
| |
Collapse
|
8
|
Nick TA, de Oliveira TE, Pilat DW, Spenkuch F, Butt HJ, Helm M, Netz PA, Berger R. Stability of a Split Streptomycin Binding Aptamer. J Phys Chem B 2016; 120:6479-89. [PMID: 27281393 DOI: 10.1021/acs.jpcb.6b02440] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Thomas A Nick
- Max Planck Institute for Polymer Research , 55128 Mainz, Germany
| | - Tiago E de Oliveira
- Instituto de Química, Universidade Federal do Rio Grande do Sul , Avenida Bento Gonçalves, 9500, 91501-970 Porto Alegre-RS, Brazil
| | - Dominik W Pilat
- Max Planck Institute for Polymer Research , 55128 Mainz, Germany
| | - Felix Spenkuch
- Johannes Gutenberg Universität Mainz , Institute of Pharmacy and Biochemistry, 55128 Mainz, Germany
| | - Hans-Jürgen Butt
- Max Planck Institute for Polymer Research , 55128 Mainz, Germany
| | - Mark Helm
- Johannes Gutenberg Universität Mainz , Institute of Pharmacy and Biochemistry, 55128 Mainz, Germany
| | - Paulo A Netz
- Instituto de Química, Universidade Federal do Rio Grande do Sul , Avenida Bento Gonçalves, 9500, 91501-970 Porto Alegre-RS, Brazil
| | - Rüdiger Berger
- Max Planck Institute for Polymer Research , 55128 Mainz, Germany
| |
Collapse
|
9
|
Atomic description of the immune complex involved in heparin-induced thrombocytopenia. Nat Commun 2015; 6:8277. [PMID: 26391892 PMCID: PMC4580983 DOI: 10.1038/ncomms9277] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 08/05/2015] [Indexed: 01/27/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is an autoimmune thrombotic disorder caused by immune complexes containing platelet factor 4 (PF4), antibodies to PF4 and heparin or cellular glycosaminoglycans (GAGs). Here we solve the crystal structures of the: (1) PF4 tetramer/fondaparinux complex, (2) PF4 tetramer/KKO-Fab complex (a murine monoclonal HIT-like antibody) and (3) PF4 monomer/RTO-Fab complex (a non-HIT anti-PF4 monoclonal antibody). Fondaparinux binds to the ‘closed' end of the PF4 tetramer and stabilizes its conformation. This interaction in turn stabilizes the epitope for KKO on the ‘open' end of the tetramer. Fondaparinux and KKO thereby collaborate to ‘stabilize' the ternary pathogenic immune complex. Binding of RTO to PF4 monomers prevents PF4 tetramerization and inhibits KKO and human HIT IgG-induced platelet activation and platelet aggregation in vitro, and thrombus progression in vivo. The atomic structures provide a basis to develop new diagnostics and non-anticoagulant therapeutics for HIT. Heparin-induced thrombocytopenia (HIT) is an autoimmune thrombotic disease with limited treatment options. Here the authors present crystallographic data on the disease-causing immune complex, providing the structural basis for the development of new diagnostic and therapeutic approaches to HIT.
Collapse
|
10
|
Nguyen TH, Greinacher A, Delcea M. Quantitative description of thermodynamic and kinetic properties of the platelet factor 4/heparin bonds. NANOSCALE 2015; 7:10130-9. [PMID: 25981976 DOI: 10.1039/c5nr02132d] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Heparin is the most important antithrombotic drug in hospitals. It binds to the endogenous tetrameric protein platelet factor 4 (PF4) forming PF4/heparin complexes which may cause a severe immune-mediated adverse drug reaction, so-called heparin-induced thrombocytopenia (HIT). Although new heparin drugs have been synthesized to reduce such a risk, detailed bond dynamics of the PF4/heparin complexes have not been clearly understood. In this study, single molecule force spectroscopy (SMFS) is utilized to characterize the interaction of PF4 with heparins of defined length (5-, 6-, 8-, 12-, and 16-mers). Analysis of the force-distance curves shows that PF4/heparin binding strength rises with increasing heparin length. In addition, two binding pathways in the PF4/short heparins (≤8-mers) and three binding pathways in the PF4/long heparins (≥8-mers) are identified. We provide a model for the PF4/heparin complexes in which short heparins bind to one PF4 tetramer, while long heparins bind to two PF4 tetramers. We propose that the interaction between long heparins and PF4s is not only due to charge differences as generally assumed, but also due to hydrophobic interaction between two PF4s which are brought close to each other by long heparin. This complicated interaction induces PF4/heparin complexes more stable than other ligand-receptor interactions. Our results also reveal that the boundary between antigenic and non-antigenic heparins is between 8- and 12-mers. These observations are particularly important to understand processes in which PF4-heparin interactions are involved and to develop new heparin-derived drugs.
Collapse
Affiliation(s)
- Thi-Huong Nguyen
- Nanostructure Group, ZIK HIKE - Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany.
| | | | | |
Collapse
|
11
|
Guo C, Fan X, Qiu H, Xiao W, Wang L, Xu B. High-resolution probing heparan sulfate-antithrombin interaction on a single endothelial cell surface: single-molecule AFM studies. Phys Chem Chem Phys 2015; 17:13301-6. [PMID: 25921251 PMCID: PMC4431915 DOI: 10.1039/c5cp01305d] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heparan sulfate (HS) plays diverse functions in multiple biological processes by interacting with a wide range of important protein ligands, such as the key anticoagulant factor, antithrombin (AT). The specific interaction of HS with a protein ligand is determined mainly by the sulfation patterns on the HS chain. Here, we reported the probing single-molecule interaction of AT and HS (both wild type and mutated) expressed on the endothelial cell surface under near-physiological conditions by atomic force microscopy (AFM). Functional AFM imaging revealed the uneven distribution of HS on the endothelial cell surface though they are highly expressed. Force spectroscopy measurements using an AT-functionalized AFM tip revealed that AT interacts with endothelial HS on the cell surface through multiple binding sites. The interaction essentially requires HS to be N-, 2-O- and/or 6-O-sulfated. This work provides a new tool to probe the HS-protein ligand interaction at a single-molecular level on the cell surface to elucidate the functional roles of HS.
Collapse
Affiliation(s)
- Cunlan Guo
- Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA, USA.
| | | | | | | | | | | |
Collapse
|
12
|
Abstract
PURPOSE OF REVIEW To review the recent developments in understanding the pathophysiology of heparin-induced thrombocytopenia (HIT) and in applying this knowledge to the treatment of patients with suspected and proven HIT. RECENT FINDINGS HIT pathophysiology is dynamic and complex. HIT pathophysiology is initiated by four essential components--heparin (Hep), platelet factor 4 (PF4), IgG antibodies against the Hep-PF4 complex, and platelet FcγRIIa. HIT is propagated by activated platelets, monocytes, endothelial cells, and coagulation proteins. Insights into the unique HIT antibody response continue to emerge, but without consensus as to the relative roles of B cells, T cells, and antigen-presenting cells. Platelet activation via FcγRIIa, the sine qua non of HIT, has become much better appreciated. Therapy remains challenging for several reasons. Suspected HIT is more frequent than proven HIT, because of the widespread use of Hep and the inadequacies of current diagnostic tests and scoring systems. In proven HIT, approved treatments reduce but do not eliminate thrombosis, and have substantial bleeding risk. Rational novel therapeutic strategies, directed at the initiating steps in HIT pathophysiology and with potential combinations staged over time, are in various phases of development. SUMMARY Progress continues in understanding the breadth of molecular and cellular players in HIT. Translation to improved diagnosis and treatment is needed.
Collapse
|