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Spiteri VA, Doutch J, Rambo RP, Bhatt JS, Gor J, Dalby PA, Perkins SJ. Using atomistic solution scattering modelling to elucidate the role of the Fc glycans in human IgG4. PLoS One 2024; 19:e0300964. [PMID: 38557973 PMCID: PMC10984405 DOI: 10.1371/journal.pone.0300964] [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: 09/21/2023] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
Human immunoglobulin G (IgG) exists as four subclasses IgG1-4, each of which has two Fab subunits joined by two hinges to a Fc subunit. IgG4 has the shortest hinge with 12 residues. The Fc subunit has two glycan chains, but the importance of glycosylation is not fully understood in IgG4. Here, to evaluate the stability and structure of non-glycosylated IgG4, we performed a multidisciplinary structural study of glycosylated and deglycosylated human IgG4 A33 for comparison with our similar study of human IgG1 A33. After deglycosylation, IgG4 was found to be monomeric by analytical ultracentrifugation; its sedimentation coefficient of 6.52 S was reduced by 0.27 S in reflection of its lower mass. X-ray and neutron solution scattering showed that the overall Guinier radius of gyration RG and its cross-sectional values after deglycosylation were almost unchanged. In the P(r) distance distribution curves, the two M1 and M2 peaks that monitor the two most common distances within IgG4 were unchanged following deglycosylation. Further insight from Monte Carlo simulations for glycosylated and deglycosylated IgG4 came from 111,382 and 117,135 possible structures respectively. Their comparison to the X-ray and neutron scattering curves identified several hundred best-fit models for both forms of IgG4. Principal component analyses showed that glycosylated and deglycosylated IgG4 exhibited different conformations from each other. Within the constraint of unchanged RG and M1-M2 values, the glycosylated IgG4 models showed more restricted Fc conformations compared to deglycosylated IgG4, but no other changes. Kratky plots supported this interpretation of greater disorder upon deglycosylation, also observed in IgG1. Overall, these more variable Fc conformations may demonstrate a generalisable impact of deglycosylation on Fc structures, but with no large conformational changes in IgG4 unlike those seen in IgG1.
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Affiliation(s)
- Valentina A. Spiteri
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - James Doutch
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, United Kingdom
| | - Robert P. Rambo
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire, United Kingdom
| | - Jayesh S. Bhatt
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Jayesh Gor
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Paul A. Dalby
- Department of Biochemical Engineering, University College London, London, United Kingdom
| | - Stephen J. Perkins
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
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2
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Tanemura H, Masuda K, Okumura T, Takagi E, Kajihara D, Kakihara H, Nonaka K, Ushioda R. Development of a stable antibody production system utilizing an Hspa5 promoter in CHO cells. Sci Rep 2022; 12:7239. [PMID: 35610229 PMCID: PMC9130236 DOI: 10.1038/s41598-022-11342-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/19/2022] [Indexed: 11/28/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are widely used for manufacturing antibody drugs. We attempted to clone a novel high-expression promoter for producing monoclonal antibodies (mAbs) based on transcriptome analysis to enhance the transcriptional abundance of mAb genes. The efficacy of conventional promoters such as CMV and hEF1α decrease in the latter phase of fed-batch cell culture. To overcome this, we screened genes whose expression was maintained or increased throughout the culture period. Since CHO cells have diverse genetic expression depending on the selected clone and culture medium, transcriptome analysis was performed on multiple clones and culture media anticipated to be used in mAb manufacturing. We thus acquired the Hspa5 promoter as a novel high-expression promoter, which uniquely enables mAb productivity per cell to improve late in the culture period. Productivity also improved for various IgG subclasses under Hspa5 promoter control, indicating this promoter’s potential universal value for mAb production. Finally, it was suggested that mAb production with this promoter is correlated with the transcription levels of endoplasmic reticulum stress-related genes. Therefore, mAb production utilizing the Hspa5 promoter might be a new method for maintaining protein homeostasis and achieving stable expression of introduced mAb genes during fed-batch culture.
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Affiliation(s)
- Hiroki Tanemura
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Kenji Masuda
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Takeshi Okumura
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Eri Takagi
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Daisuke Kajihara
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Hirofumi Kakihara
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Koichi Nonaka
- Biologics Technology Research Laboratories Biologics Division, Daiichi Sankyo Co., Ltd., 2716-1, Aza Kurakake, Oaza Akaiwa, Chiyoda-machi, Oura-gun, Gunma, 370-0503, Japan
| | - Ryo Ushioda
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto City, 603-8555, Japan. .,Institute for Protein Dynamics, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto City, 603-8555, Japan.
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3
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Spiteri VA, Goodall M, Doutch J, Rambo RP, Gor J, Perkins SJ. Solution structures of human myeloma IgG3 antibody reveal extended Fab and Fc regions relative to the other IgG subclasses. J Biol Chem 2021; 297:100995. [PMID: 34302810 PMCID: PMC8371214 DOI: 10.1016/j.jbc.2021.100995] [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: 05/03/2021] [Revised: 07/08/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022] Open
Abstract
Human immunoglobulin G subclass 3 (IgG3) possesses a uniquely long hinge region that separates its Fab antigen-binding and Fc receptor-binding regions. Owing to this hinge length, the molecular structure of full-length IgG3 remains elusive, and the role of the two conserved Fc glycosylation sites are unknown. To address these issues, we subjected glycosylated and deglycosylated human myeloma IgG3 to multidisciplinary solution structure studies. Using analytical ultracentrifugation, the elongated structure of IgG3 was determined from the reduced sedimentation coefficients s020,w of 5.82 to 6.29 S for both glycosylated and deglycosylated IgG3. X-ray and neutron scattering showed that the Guinier RG values were 6.95 nm for glycosylated IgG3 and were unchanged after deglycosylation, again indicating an elongated structure. The distance distribution function P(r) showed a maximum length of 25 to 28 nm and three distinct maxima. The molecular structure of IgG3 was determined using atomistic modeling based on molecular dynamics simulations of the IgG3 hinge and Monte Carlo simulations to identify physically realistic arrangements of the Fab and Fc regions. This resulted in libraries containing 135,135 and 73,905 glycosylated and deglycosylated IgG3 structures, respectively. Comparisons with the X-ray and neutron scattering curves gave 100 best-fit models for each form of IgG3 that accounted for the experimental scattering curves. These models revealed the first molecular structures for full-length IgG3. The structures exhibited relatively restricted Fab and Fc conformations joined by an extended semirigid hinge, which explains the potent effector functions of IgG3 relative to the other subclasses IgG1, IgG2, and IgG4.
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Affiliation(s)
- Valentina A Spiteri
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Margaret Goodall
- Institute for Biomedical Research, University of Birmingham, Birmingham, United Kingdom
| | - James Doutch
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, United Kingdom
| | - Robert P Rambo
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Jayesh Gor
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.
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4
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Abstract
Antibody-dependent complement activation plays a major role in various pathophysiological processes in our body, including infection, inflammation, autoimmunity, and transplant rejection. In order to activate complement, antibodies should bind to target cells and recruit complement component C1. C1 is a large, multimolecular complex that consists of the antibody recognition protein C1q and a heterotetramer of proteases (C1r2s2). Although it is believed that interactions between C1 and IgGs are solely mediated by C1q, we here show that C1r2s2 proteases affect the capacity of C1q to form an avid complex with surface-bound IgG molecules. Furthermore, we demonstrate that C1q–IgG stability is influenced by IgG oligomerization and that promoting IgG oligomerization improves phagocytosis of the pathogenic bacterium Staphylococcus aureus. Complement is an important effector mechanism for antibody-mediated clearance of infections and tumor cells. Upon binding to target cells, the antibody’s constant (Fc) domain recruits complement component C1 to initiate a proteolytic cascade that generates lytic pores and stimulates phagocytosis. The C1 complex (C1qr2s2) consists of the large recognition protein C1q and a heterotetramer of proteases C1r and C1s (C1r2s2). While interactions between C1 and IgG-Fc are believed to be mediated by the globular heads of C1q, we here find that C1r2s2 proteases affect the capacity of C1q to form an avid complex with surface-bound IgG molecules (on various 2,4-dinitrophenol [DNP]-coated surfaces and pathogenic Staphylococcus aureus). The extent to which C1r2s2 contributes to C1q–IgG stability strongly differs between human IgG subclasses. Using antibody engineering of monoclonal IgG, we reveal that hexamer-enhancing mutations improve C1q–IgG stability, both in the absence and presence of C1r2s2. In addition, hexamer-enhanced IgGs targeting S. aureus mediate improved complement-dependent phagocytosis by human neutrophils. Altogether, these molecular insights into complement binding to surface-bound IgGs could be important for optimal design of antibody therapies.
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5
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Spiteri VA, Doutch J, Rambo RP, Gor J, Dalby PA, Perkins SJ. Solution structure of deglycosylated human IgG1 shows the role of C H2 glycans in its conformation. Biophys J 2021; 120:1814-1834. [PMID: 33675758 DOI: 10.1016/j.bpj.2021.02.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/04/2021] [Accepted: 02/24/2021] [Indexed: 02/06/2023] Open
Abstract
The human immunoglobulin G (IgG) class is the most prevalent antibody in serum, with the IgG1 subclass being the most abundant. IgG1 is composed of two Fab regions connected to a Fc region through a 15-residue hinge peptide. Two glycan chains are conserved in the Fc region in IgG; however, their importance for the structure of intact IgG1 has remained unclear. Here, we subjected glycosylated and deglycosylated monoclonal human IgG1 (designated as A33) to a comparative multidisciplinary structural study of both forms. After deglycosylation using peptide:N-glycosidase F, analytical ultracentrifugation showed that IgG1 remained monomeric and the sedimentation coefficients s020,w of IgG1 decreased from 6.45 S by 0.16-0.27 S. This change was attributed to the reduction in mass after glycan removal. X-ray and neutron scattering revealed changes in the Guinier structural parameters after deglycosylation. Although the radius of gyration (RG) was unchanged, the cross-sectional radius of gyration (RXS-1) increased by 0.1 nm, and the commonly occurring distance peak M2 of the distance distribution curve P(r) increased by 0.4 nm. These changes revealed that the Fab-Fc separation in IgG1 was perturbed after deglycosylation. To explain these changes, atomistic scattering modeling based on Monte Carlo simulations resulted in 123,284 and 119,191 trial structures for glycosylated and deglycosylated IgG1 respectively. From these, 100 x-ray and neutron best-fit models were determined. For these, principal component analyses identified five groups of structural conformations that were different for glycosylated and deglycosylated IgG1. The Fc region in glycosylated IgG1 showed a restricted range of conformations relative to the Fab regions, whereas the Fc region in deglycosylated IgG1 showed a broader conformational spectrum. These more variable Fc conformations account for the loss of binding to the Fcγ receptor in deglycosylated IgG1.
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Affiliation(s)
- Valentina A Spiteri
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - James Doutch
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, United Kingdom
| | - Robert P Rambo
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Jayesh Gor
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Paul A Dalby
- Department of Biochemical Engineering, University College London, London, United Kingdom
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.
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6
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Deveuve Q, Gouilleux-Gruart V, Thibault G, Lajoie L. [The hinge region of therapeutic antibodies: major importance of a short sequence]. Med Sci (Paris) 2020; 35:1098-1105. [PMID: 31903923 DOI: 10.1051/medsci/2019218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The hinge region is a short sequence of the heavy chains (H) of antibodies linking the Fab (Fragment antigen binding) region to the Fc (Fragment crystallisable) region. The functional properties of the four IgG subclasses partly result from the sequence differences of their hinge regions as some amino acids of the lower hinge region are located within or in the close vicinity of the C1q and FcγR binding sites on the IgG H chains. In addition, the hinge is susceptible to proteolytic cleavage by many proteases present in tumor and/or inflammatory microenvironment capable of affecting functional responses. Thus, an optimal format of the hinge region remains a major challenge for the development of new therapeutic antibodies.
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Affiliation(s)
- Quentin Deveuve
- Université de Tours, EA7501 GICC (Groupe Innovation et Ciblage Cellulaire), équipe FRAME (Fc Récepteurs, Anticorps et MicroEnvironnement), 37032 Tours, France
| | - Valérie Gouilleux-Gruart
- Université de Tours, EA7501 GICC (Groupe Innovation et Ciblage Cellulaire), équipe FRAME (Fc Récepteurs, Anticorps et MicroEnvironnement), 37032 Tours, France - Service d'immunologie, CHRU de Tours, 37044 Tours, France
| | - Gilles Thibault
- Université de Tours, EA7501 GICC (Groupe Innovation et Ciblage Cellulaire), équipe FRAME (Fc Récepteurs, Anticorps et MicroEnvironnement), 37032 Tours, France - Service d'immunologie, CHRU de Tours, 37044 Tours, France
| | - Laurie Lajoie
- Université de Tours, EA7501 GICC (Groupe Innovation et Ciblage Cellulaire), équipe FRAME (Fc Récepteurs, Anticorps et MicroEnvironnement), 37032 Tours, France
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7
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Wright DW, Elliston ELK, Hui GK, Perkins SJ. Atomistic Modeling of Scattering Curves for Human IgG1/4 Reveals New Structure-Function Insights. Biophys J 2019; 117:2101-2119. [PMID: 31708160 PMCID: PMC6895691 DOI: 10.1016/j.bpj.2019.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/03/2019] [Accepted: 10/18/2019] [Indexed: 11/11/2022] Open
Abstract
Small angle x-ray and neutron scattering are techniques that give solution structures for large macromolecules. The creation of physically realistic atomistic models from known high-resolution structures to determine joint x-ray and neutron scattering best-fit structures offers a, to our knowledge, new method that significantly enhances the utility of scattering. To validate this approach, we determined scattering curves for two human antibody subclasses, immunoglobulin G (IgG) 1 and IgG4, on five different x-ray and neutron instruments to show that these were reproducible, then we modeled these by Monte Carlo simulations. The two antibodies have different hinge lengths that connect their antigen-binding Fab and effector-binding Fc regions. Starting from 231,492 and 190,437 acceptable conformations for IgG1 and IgG4, respectively, joint x-ray and neutron scattering curve fits gave low goodness-of-fit R factors for 28 IgG1 and 2748 IgG4 structures that satisfied the disulphide connectivity in their hinges. These joint best-fit structures showed that the best-fit IgG1 models had a greater separation between the centers of their Fab regions than those for IgG4, in agreement with their hinge lengths of 15 and 12 residues, respectively. The resulting asymmetric IgG1 solution structures resembled its crystal structure. Both symmetric and asymmetric solution structures were determined for IgG4. Docking simulations with our best-fit IgG4 structures showed greater steric clashes with its receptor to explain its weaker FcγRI receptor binding compared to our best-fit IgG1 structures with fewer clashes and stronger receptor binding. Compared to earlier approaches for fitting molecular antibody structures by solution scattering, we conclude that this joint fit approach based on x-ray and neutron scattering data, combined with Monte Carlo simulations, significantly improved our understanding of antibody solution structures. The atomistic nature of the output extended our understanding of known functional differences in Fc receptor binding between IgG1 and IgG4.
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Affiliation(s)
- David W Wright
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Emma L K Elliston
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Gar Kay Hui
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Stephen J Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.
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8
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Hui GK, Gardener AD, Begum H, Eldrid C, Thalassinos K, Gor J, Perkins SJ. The solution structure of the human IgG2 subclass is distinct from those for human IgG1 and IgG4 providing an explanation for their discrete functions. J Biol Chem 2019; 294:10789-10806. [PMID: 31088911 PMCID: PMC6635440 DOI: 10.1074/jbc.ra118.007134] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/03/2019] [Indexed: 11/06/2022] Open
Abstract
Human IgG2 antibody displays distinct therapeutically-useful properties compared with the IgG1, IgG3, and IgG4 antibody subclasses. IgG2 is the second most abundant IgG subclass, being able to bind human FcγRII/FcγRIII but not to FcγRI or complement C1q. Structural information on IgG2 is limited by the absence of a full-length crystal structure for this. To this end, we determined the solution structure of human myeloma IgG2 by atomistic X-ray and neutron-scattering modeling. Analytical ultracentrifugation disclosed that IgG2 is monomeric with a sedimentation coefficient (s20, w0) of 7.2 S. IgG2 dimer formation was ≤5% and independent of the buffer conditions. Small-angle X-ray scattering in a range of NaCl concentrations and in light and heavy water revealed that the X-ray radius of gyration (Rg ) is 5.2-5.4 nm, after allowing for radiation damage at higher concentrations, and that the neutron Rg value of 5.0 nm remained unchanged in all conditions. The X-ray and neutron distance distribution curves (P(r)) revealed two peaks, M1 and M2, that were unchanged in different buffers. The creation of >123,000 physically-realistic atomistic models by Monte Carlo simulations for joint X-ray and neutron-scattering curve fits, constrained by the requirement of correct disulfide bridges in the hinge, resulted in the determination of symmetric Y-shaped IgG2 structures. These molecular structures were distinct from those for asymmetric IgG1 and asymmetric and symmetric IgG4 and were attributable to the four hinge disulfides. Our IgG2 structures rationalize the existence of the human IgG1, IgG2, and IgG4 subclasses and explain the receptor-binding functions of IgG2.
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Affiliation(s)
- Gar Kay Hui
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Antoni D Gardener
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Halima Begum
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Charles Eldrid
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, WC1E 7HX, United Kingdom
| | - Jayesh Gor
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Stephen J Perkins
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
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Dudek S, Weißmüller S, Anzaghe M, Miller L, Sterr S, Hoffmann K, Hengel H, Waibler Z. Human Fcγ receptors compete for TGN1412 binding that determines the antibody's effector function. Eur J Immunol 2019; 49:1117-1126. [PMID: 31002172 DOI: 10.1002/eji.201847924] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 02/21/2019] [Accepted: 04/09/2019] [Indexed: 11/07/2022]
Abstract
The first-in-human clinical trial of the CD28-specific monoclonal antibody (mAb) TGN1412 resulted in a life-threatening cytokine release syndrome. Although TGN1412 was designed as IgG4, known for weak Fc:Fcγ receptor (FcγR) interactions, these interactions contributed to TGN1412-induced T-cell activation. Using cell lines (TFs) expressing human FcγRI, -IIa, -IIb, or -III, we show that TGN1412 and TGN1412 as IgG1 and IgG2 are bound by FcγRs as it can be deduced from literature. However, upon coculture of TGN1412-decorated T cells with TFs or human primary blood cells, we observed that binding capacities by FcγRs do not correlate with the strength of the mediated effector function. FcγRIIa and FcγRIIb, showing no or very minor binding to TGN1412, mediated strongest T cell proliferation, while high-affinity FcγRI, exhibiting strong TGN1412 binding, mediated hardly any T-cell proliferation. These findings are of biological relevance because we show that FcγRI binds TGN1412, thus prevents binding to FcγRIIa or FcγRIIb, and consequently disables T-cell proliferation. In line with this, FcγRI- FcγRII+ but not FcγRI+ FcγRII+ monocytes mediate TGN1412-induced T-cell proliferation. Collectively, by using TGN1412 as example, our results indicate that binding of monomeric IgG subclasses does not predict the FcγR-mediated effector function, which has major implications for the design of therapeutic mAbs.
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Affiliation(s)
- Simone Dudek
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
| | - Sabrina Weißmüller
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
| | - Martina Anzaghe
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
| | - Lilija Miller
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
| | - Sarah Sterr
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
| | - Katja Hoffmann
- Institute of Virology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hartmut Hengel
- Institute of Virology, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Zoe Waibler
- Product Testing of Immunological Biopharmaceuticals, Division of Immunology, Paul-Ehrlich-Institut, Langen, Germany
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10
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Blech M, Hörer S, Kuhn AB, Kube S, Göddeke H, Kiefer H, Zang Y, Alber Y, Kast SM, Westermann M, Tully MD, Schäfer LV, Garidel P. Structure of a Therapeutic Full-Length Anti-NPRA IgG4 Antibody: Dissecting Conformational Diversity. Biophys J 2019; 116:1637-1649. [PMID: 31023536 DOI: 10.1016/j.bpj.2019.03.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 01/02/2023] Open
Abstract
We report the x-ray crystal structure of intact, full-length human immunoglobulin (IgG4) at 1.8 Å resolution. The data for IgG4 (S228P), an antibody targeting the natriuretic peptide receptor A, show a previously unrecognized type of Fab-Fc orientation with a distorted λ-shape in which one Fab-arm is oriented toward the Fc portion. Detailed structural analysis by x-ray crystallography and molecular simulations suggest that this is one of several conformations coexisting in a dynamic equilibrium state. These results were confirmed by small angle x-ray scattering in solution. Furthermore, electron microscopy supported these findings by preserving molecule classes of different conformations. This study fosters our understanding of IgG4 in particular and our appreciation of antibody flexibility in general. Moreover, we give insights into potential biological implications, specifically for the interaction of human anti-natriuretic peptide receptor A IgG4 with the neonatal Fc receptor, Fcγ receptors, and complement-activating C1q by considering conformational flexibility.
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Affiliation(s)
- Michaela Blech
- Innovation Unit, Pharmaceutical Development Biologics, Biberach (Riss), Germany.
| | - Stefan Hörer
- Department Lead Identification and Optimization Support, Structural Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach (Riss), Germany
| | | | - Sebastian Kube
- Innovation Unit, Pharmaceutical Development Biologics, Biberach (Riss), Germany
| | - Hendrik Göddeke
- Theoretical Chemistry, Ruhr University Bochum, Bochum, Germany
| | - Hans Kiefer
- University of Applied Sciences Biberach, Biberach (Riss), Germany
| | - Yuguo Zang
- University of Applied Sciences Biberach, Biberach (Riss), Germany
| | - Yannic Alber
- Physikalische Chemie III, Technische Universität Dortmund, Dortmund, Germany
| | - Stefan M Kast
- Physikalische Chemie III, Technische Universität Dortmund, Dortmund, Germany
| | - Martin Westermann
- Elektronenmikroskopisches Zentrum, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Mark D Tully
- European Synchrotron Radiation Facility, Grenoble, France
| | - Lars V Schäfer
- Theoretical Chemistry, Ruhr University Bochum, Bochum, Germany
| | - Patrick Garidel
- Innovation Unit, Pharmaceutical Development Biologics, Biberach (Riss), Germany.
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11
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Lyophilization of High-Concentration Protein Formulations. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2019. [DOI: 10.1007/978-1-4939-8928-7_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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12
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Hansen K, Lau AM, Giles K, McDonnell JM, Struwe WB, Sutton BJ, Politis A. A Mass-Spectrometry-Based Modelling Workflow for Accurate Prediction of IgG Antibody Conformations in the Gas Phase. Angew Chem Int Ed Engl 2018; 57:17194-17199. [PMID: 30408305 PMCID: PMC6392142 DOI: 10.1002/anie.201812018] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 11/09/2022]
Abstract
Immunoglobulins are biomolecules involved in defence against foreign substances. Flexibility is key to their functional properties in relation to antigen binding and receptor interactions. We have developed an integrative strategy combining ion mobility mass spectrometry (IM-MS) with molecular modelling to study the conformational dynamics of human IgG antibodies. Predictive models of all four human IgG subclasses were assembled and their dynamics sampled in the transition from extended to collapsed state during IM-MS. Our data imply that this collapse of IgG antibodies is related to their intrinsic structural features, including Fab arm flexibility, collapse towards the Fc region, and the length of their hinge regions. The workflow presented here provides an accurate structural representation in good agreement with the observed collision cross section for these flexible IgG molecules. These results have implications for studying other nonglobular flexible proteins.
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Affiliation(s)
- Kjetil Hansen
- Department of ChemistryKing's College London7 Trinity StreetLondonSE1 1DBUK
| | - Andy M. Lau
- Department of ChemistryKing's College London7 Trinity StreetLondonSE1 1DBUK
| | | | | | | | - Brian J. Sutton
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonUK
| | - Argyris Politis
- Department of ChemistryKing's College London7 Trinity StreetLondonSE1 1DBUK
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13
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Hansen K, Lau AM, Giles K, McDonnell JM, Struwe WB, Sutton BJ, Politis A. A Mass‐Spectrometry‐Based Modelling Workflow for Accurate Prediction of IgG Antibody Conformations in the Gas Phase. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201812018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kjetil Hansen
- Department of Chemistry King's College London 7 Trinity Street London SE1 1DB UK
| | - Andy M. Lau
- Department of Chemistry King's College London 7 Trinity Street London SE1 1DB UK
| | - Kevin Giles
- Waters Corp. Stamford Road Wilmslow SK9 4AX UK
| | - James M. McDonnell
- Randall Centre for Cell and Molecular Biophysics King's College London UK
| | | | - Brian J. Sutton
- Randall Centre for Cell and Molecular Biophysics King's College London UK
| | - Argyris Politis
- Department of Chemistry King's College London 7 Trinity Street London SE1 1DB UK
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14
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Liu M, Hao M. Unique properties of IgG4 antibody and its clinical application in autoimmune pancreatitis. Scand J Gastroenterol 2018; 53:1121-1131. [PMID: 30175675 DOI: 10.1080/00365521.2018.1476915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Autoimmune pancreatitis (AIP) is defined as a unique form of chronic pancreatitis characterized by clinical presentation with obstructive jaundice, a dense lymphoplasmacytic infiltrate and fibrosis histologically, and a dramatic response to steroids therapeutically. The possible role of IgG4 in driving the pathology of AIP is a controversial subject that has not been addressed satisfactorily. Objective: The purpose of this review is to discuss the unique biology of IgG4 that are important for its role and the clinical applications for serologic detection. METHODS Review of current literature about IgG4 antibody in the clinical application in AIP. RESULTS High serum levels of IgG4 are an important biomarker and broadly used for diagnosis, differentiation from diseases especially pancreatic cancer, and as a parameter to indicate disease activity, extra-pancreatic lesions, and treatment monitoring. However, some controversial studies show it has a limited specificity and sensitivity in these conditions. Conclusion: Although increasing studies have promoted our understanding of the structure and function of IgG4, there is still dilemma between the beneficial and the adverse aspect of IgG4 in the pathogenesis of AIP.
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Affiliation(s)
- Min Liu
- a Department of Clinical Laboratory , Jinan Dermatosis Prevention and Control Hospital , Jinan , People's Republic of China
| | - Mingju Hao
- b Department of Clinical Laboratory , Qianfo Mountain Hospital of Shandong University , Jinan , People's Republic of China
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15
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Gomes CSG, Fashina A, Fernández‐Castané A, Overton TW, Hobley TJ, Theodosiou E, Thomas ORT. Magnetic hydrophobic-charge induction adsorbents for the recovery of immunoglobulins from antiserum feedstocks by high-gradient magnetic fishing. JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY (OXFORD, OXFORDSHIRE : 1986) 2018; 93:1901-1915. [PMID: 30008504 PMCID: PMC6032826 DOI: 10.1002/jctb.5599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 05/07/2023]
Abstract
BACKGROUND The extraction of biopharmaceuticals from plasma and serum often employs overly complicated antiquated procedures that can inflict serious damage on especially prone protein targets and which afford low purification power and overall yields. This paper describes systematic development of a high-gradient magnetic fishing process for recovery of immunoglobulins from unclarified antiserum. RESULTS Non-porous superparamagnetic particles were transformed into hydrophobic-charge induction adsorbents and then used to recover immunoglobulins from rabbit antiserum feedstocks. Comprehensive characterisation tests conducted with variously diluted clarified antiserum on a magnetic rack revealed that immunoglobulin binding was rapid (equilibrium reached in <45 s), strong (Kd < 0.1 mg mL-1), of high capacity (Qmax = 214 mg g-1), and pH and ionic strength dependent. In a high-gradient magnetic fishing process conducted with the same adsorbent, and a conventional 'magnetic filter + recycle loop' arrangement, >72% of the immunoglobulin present in an unclarified antiserum feed was recovered in 0.5 h in >3-fold purified form. CONCLUSIONS Fast magnetic particle based capture of antibodies from an unclarified high-titre feed has been demonstrated. Efficient product recovery from ultra-high titre bioprocess liquors by high-gradient magnetic fishing requires that improved magnetic adsorbents displaying high selectivity, ultra-high capacity and operational robustness are used with 'state-of-the-art' rotor-stator magnetic separators. © 2018 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Cláudia SG Gomes
- Institute of Biotechnology and BiomedicineTechnical University of DenmarkLyngbyDenmark
| | - Adedayo Fashina
- School of Chemical EngineeringUniversity of BirminghamBirminghamUK
| | | | | | - Timothy J Hobley
- National Food InstituteTechnical University of DenmarkLyngbyDenmark
| | | | - Owen RT Thomas
- School of Chemical EngineeringUniversity of BirminghamBirminghamUK
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16
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Zhou W, Lin S, Chen R, Liu J, Li Y. Characterization of antibody-C1q interactions by Biolayer Interferometry. Anal Biochem 2018; 549:143-148. [DOI: 10.1016/j.ab.2018.03.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 02/20/2018] [Accepted: 03/21/2018] [Indexed: 12/17/2022]
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17
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Li Y, Yang M, Zhang R, Liu W, Zhang K, Wen W, Yi L, Wang Q, Hao M, Yang H, Chang J, Li J. Evaluation of serum immunoglobulins concentrations and distributions in vitiligo patients. Immunol Res 2017; 64:1150-1156. [PMID: 27417998 DOI: 10.1007/s12026-016-8809-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Vitiligo is a dermatological disorder with an autoimmune mechanism characterized by production of a variety of autoantibodies. Different levels of immunoglobulins can indicate the presence and the stage of some autoimmune diseases. We aimed to investigate serum IgA, IgM and IgG subclass levels and melanocyte-reactive antibodies in 65 vitiligo patients by the immunonephelometric assay (35 healthy people as controls). Compared with normal controls, a significant increase in total IgG, IgG1 and IgG2 (p = .005, p = .003 and p = .043, respectively) was observed in progressive nonsegmental vitiligo patients. Also, we found a significant decrease in IgG3 (p = .000 and p = .023) in progressive nonsegmental vitiligo patients and segmental patients. Moreover, we found the serum levels of IgG4 subclass in stable nonsegmental patients were significantly higher than those in normal controls (p = .018). Compared with controls, the positive rates of melanocyte-reactive antibodies were higher in progressive nonsegmental patients and stable nonsegmental patients (p = .032 and p = .046, respectively). Furthermore, we found higher level of IgG4 and lower level of IgM in male than those in female. Higher IgG1 level was also observed in patients with a family history than in those without a family history. In addition, there was a significant inverse correlation between the concentrations of IgG4 and disease duration. Our evaluation about the level of immunoglobulins might provide a useful insight into the pathological process of vitiligo.
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Affiliation(s)
- Yulong Li
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Min Yang
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Rui Zhang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Wan Liu
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Kuo Zhang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Wei Wen
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Lang Yi
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Qiaoxian Wang
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Mingju Hao
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Hui Yang
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China
| | - Jianmin Chang
- Department of Dermatology, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China.
| | - Jinming Li
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, No. 1 Dahua Road, Dongdan, Beijing, 100730, People's Republic of China. .,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.
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18
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Human myeloma IgG4 reveals relatively rigid asymmetric Y-like structure with different conformational stability of C H 2 domains. Mol Immunol 2017; 92:199-210. [DOI: 10.1016/j.molimm.2017.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 10/10/2017] [Accepted: 10/17/2017] [Indexed: 11/20/2022]
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19
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Piche-Nicholas NM, Avery LB, King AC, Kavosi M, Wang M, O'Hara DM, Tchistiakova L, Katragadda M. Changes in complementarity-determining regions significantly alter IgG binding to the neonatal Fc receptor (FcRn) and pharmacokinetics. MAbs 2017; 10:81-94. [PMID: 28991504 PMCID: PMC5800364 DOI: 10.1080/19420862.2017.1389355] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A large body of data exists demonstrating that neonatal Fc receptor (FcRn) binding of an IgG via its Fc CH2-CH3 interface trends with the pharmacokinetics (PK) of IgG. We have observed that PK of IgG molecules vary widely, even when they share identical Fc domains. This led us to hypothesize that domains distal from the Fc could contribute to FcRn binding and affect PK. In this study, we explored the role of these IgG domains in altering the affinity between IgG and FcRn. Using a surface plasmon resonance-based assay developed to examine the steady-state binding affinity (KD) of IgG molecules to FcRn, we dissected the contributions of IgG domains in modulating the affinity between FcRn and IgG. Through analysis of a broad collection of therapeutic antibodies containing more than 50 unique IgG molecules, we demonstrated that variable domains, and in particular complementarity-determining regions (CDRs), significantly alter binding affinity to FcRn in vitro. Furthermore, a panel of IgG molecules differing only by 1–5 mutations in CDRs altered binding affinity to FcRn in vitro, by up to 79-fold, and the affinity values correlated with calculated isoelectric point values of both variable domains and CDR-L3. In addition, tighter affinity values trend with faster in vivo clearance of a set of IgG molecules differing only by 1–3 mutations in human FcRn transgenic mice. Understanding the role of CDRs in modulation of IgG affinity to FcRn in vitro and their effect on PK of IgG may have far-reaching implications in the optimization of IgG therapeutics.
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Affiliation(s)
| | | | - Amy C King
- a BioMedicine Design, Pfizer Inc. , Cambridge , MA , USA
| | - Mania Kavosi
- b BioMedicine Design, Pfizer Inc. , Andover , MA , USA
| | - Mengmeng Wang
- b BioMedicine Design, Pfizer Inc. , Andover , MA , USA
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20
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High-concentration protein formulations: How high is high? Eur J Pharm Biopharm 2017; 119:353-360. [DOI: 10.1016/j.ejpb.2017.06.029] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 01/25/2023]
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21
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Mazzer AR, Clifton LA, Perevozchikova T, Butler PD, Roberts CJ, Bracewell DG. Neutron reflectivity measurement of protein A-antibody complex at the solid-liquid interface. J Chromatogr A 2017; 1499:118-131. [PMID: 28410804 PMCID: PMC5408906 DOI: 10.1016/j.chroma.2017.03.084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/15/2017] [Accepted: 03/30/2017] [Indexed: 01/05/2023]
Abstract
The orientation of IgG4 adsorbed at the solid-liquid interface was probed. A chromatography resin was mimicked by attaching protein A to a silica surface. Neutron reflectivity was used to measure protein A and adsorbed IgG structures. Protein A-modified silica was blocked with either BSA or PEG before IgG adsorption. Adsorbed IgG extended up to 230 Å from the surface, depending on blocking strategy.
Chromatography is a ubiquitous unit operation in the purification of biopharmaceuticals yet few studies have addressed the biophysical characterisation of proteins at the solution-resin interface. Chromatography and other adsorption and desorption processes have been shown to induce protein aggregation which is undesirable in biopharmaceutical products. In order to advance understanding of how adsorption processes might impact protein stability, neutron reflectivity was used to characterise the structure of adsorbed immunoglobulin G (IgG) on model surfaces. In the first model system, IgG was adsorbed directly to silica and demonstrated a side-on orientation with high surface contact. A maximum dimension of 60 Å in the surface normal direction and high density surface coverage were observed under pH 4.1 conditions. In chromatography buffers, pH was found to influence IgG packing density and orientation at the solid-liquid interface. In the second model system, which was designed to mimic an affinity chromatography surface, protein A was attached to a silica surface to produce a configuration representative of a porous glass chromatography resin. Interfacial structure was probed during sequential stages from ligand attachment, through to IgG binding and elution. Adsorbed IgG structures extended up to 250 Å away from the surface and showed dependence on surface blocking strategies. The data was suggestive of two IgG molecules bound to protein A with a somewhat skewed orientation and close proximity to the silica surface. The findings provide insight into the orientation of adsorbed antibody structures under conditions encountered during chromatographic separations.
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Affiliation(s)
- Alice R Mazzer
- Dept. Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Luke A Clifton
- ISIS, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0QX, UK
| | - Tatiana Perevozchikova
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Paul D Butler
- National Institute of Standards and Technology, 100 Bureau Drive, Bldg. 235, Gaithersburg, MD 20899-8562, USA
| | - Christopher J Roberts
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Daniel G Bracewell
- Dept. Biochemical Engineering, University College London, Gower Street, London, WC1E 6BT, UK.
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22
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Perkins SJ, Wright DW, Zhang H, Brookes EH, Chen J, Irving TC, Krueger S, Barlow DJ, Edler KJ, Scott DJ, Terrill NJ, King SM, Butler PD, Curtis JE. Atomistic modelling of scattering data in the Collaborative Computational Project for Small Angle Scattering (CCP-SAS). J Appl Crystallogr 2016; 49:1861-1875. [PMID: 27980506 PMCID: PMC5139988 DOI: 10.1107/s160057671601517x] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 09/26/2016] [Indexed: 11/10/2022] Open
Abstract
The capabilities of current computer simulations provide a unique opportunity to model small-angle scattering (SAS) data at the atomistic level, and to include other structural constraints ranging from molecular and atomistic energetics to crystallography, electron microscopy and NMR. This extends the capabilities of solution scattering and provides deeper insights into the physics and chemistry of the systems studied. Realizing this potential, however, requires integrating the experimental data with a new generation of modelling software. To achieve this, the CCP-SAS collaboration (http://www.ccpsas.org/) is developing open-source, high-throughput and user-friendly software for the atomistic and coarse-grained molecular modelling of scattering data. Robust state-of-the-art molecular simulation engines and molecular dynamics and Monte Carlo force fields provide constraints to the solution structure inferred from the small-angle scattering data, which incorporates the known physical chemistry of the system. The implementation of this software suite involves a tiered approach in which GenApp provides the deployment infrastructure for running applications on both standard and high-performance computing hardware, and SASSIE provides a workflow framework into which modules can be plugged to prepare structures, carry out simulations, calculate theoretical scattering data and compare results with experimental data. GenApp produces the accessible web-based front end termed SASSIE-web, and GenApp and SASSIE also make community SAS codes available. Applications are illustrated by case studies: (i) inter-domain flexibility in two- to six-domain proteins as exemplified by HIV-1 Gag, MASP and ubiquitin; (ii) the hinge conformation in human IgG2 and IgA1 antibodies; (iii) the complex formed between a hexameric protein Hfq and mRNA; and (iv) synthetic 'bottlebrush' polymers.
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Affiliation(s)
- Stephen J. Perkins
- Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - David W. Wright
- Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Hailiang Zhang
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
| | - Emre H. Brookes
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | - Jianhan Chen
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Thomas C. Irving
- Department of Biology, Illinois Institute of Technology, 3101 S. Dearborn, Chicago, IL 60616, USA
| | - Susan Krueger
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
| | - David J. Barlow
- Pharmacy Department, Franklin-Wilkins Building, King’s College London, 150 Stamford Street, London SE1 9NH, UK
| | - Karen J. Edler
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - David J. Scott
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, UK
- Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0FA, UK
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Nicholas J. Terrill
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Chilton, Didcot, Oxfordshire OX11 0DE, UK
| | - Stephen M. King
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Paul D. Butler
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
- Department of Chemistry, The University of Tennessee, Knoxville, TN 37996-1600, USA
| | - Joseph E. Curtis
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, USA
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23
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Abstract
IgG4, the least represented human IgG subclass in serum, is an intriguing antibody with unique biological properties, such as the ability to undergo Fab-arm exchange and limit immune complex formation. The lack of effector functions, such as antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity, is desirable for therapeutic purposes. IgG4 plays a protective role in allergy by acting as a blocking antibody, and inhibiting mast cell degranulation, but a deleterious role in malignant melanoma, by impeding IgG1-mediated anti-tumor immunity. These findings highlight the importance of understanding the interaction between IgG4 and Fcγ receptors. Despite a wealth of structural information for the IgG1 subclass, including complexes with Fcγ receptors, and structures for intact antibodies, high-resolution crystal structures were not reported for IgG4-Fc until recently. Here, we highlight some of the biological properties of human IgG4, and review the recent crystal structures of IgG4-Fc. We discuss the unexpected conformations adopted by functionally important Cγ2 domain loops, and speculate about potential implications for the interaction between IgG4 and FcγRs.
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Affiliation(s)
- Anna M Davies
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | - Brian J Sutton
- Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
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24
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Crescioli S, Correa I, Karagiannis P, Davies AM, Sutton BJ, Nestle FO, Karagiannis SN. IgG4 Characteristics and Functions in Cancer Immunity. Curr Allergy Asthma Rep 2016; 16:7. [PMID: 26742760 PMCID: PMC4705142 DOI: 10.1007/s11882-015-0580-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IgG4 is the least abundant subclass of IgG in normal human serum, but elevated IgG4 levels are triggered in response to a chronic antigenic stimulus and inflammation. Since the immune system is exposed to tumor-associated antigens over a relatively long period of time, and tumors notoriously promote inflammation, it is unsurprising that IgG4 has been implicated in certain tumor types. Despite differing from other IgG subclasses by only a few amino acids, IgG4 possesses unique structural characteristics that may be responsible for its poor effector function potency and immunomodulatory properties. We describe the unique attributes of IgG4 that may be responsible for these regulatory functions, particularly in the cancer context. We discuss the inflammatory conditions in tumors that support IgG4, the emerging and proposed mechanisms by which IgG4 may contribute to tumor-associated escape from immune surveillance and implications for cancer immunotherapy.
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Affiliation(s)
- Silvia Crescioli
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine; Faculty of Life Sciences and Medicine, King's College London, London, UK. .,NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, King's College London, London, UK.
| | - Isabel Correa
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine; Faculty of Life Sciences and Medicine, King's College London, London, UK. .,NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, King's College London, London, UK.
| | - Panagiotis Karagiannis
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine; Faculty of Life Sciences and Medicine, King's College London, London, UK. .,NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, King's College London, London, UK.
| | - Anna M Davies
- Randall Division of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK. .,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
| | - Brian J Sutton
- Randall Division of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK. .,Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
| | - Frank O Nestle
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine; Faculty of Life Sciences and Medicine, King's College London, London, UK. .,NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, King's College London, London, UK.
| | - Sophia N Karagiannis
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine; Faculty of Life Sciences and Medicine, King's College London, London, UK. .,NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, King's College London, London, UK. .,St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine, Kings' College London and NIHR Biomedical Research Centre at Guy's and St. Thomas's Hospitals and King's College London, Guy's Hospital, Tower Wing, 9th Floor, London, SE1 9RT, UK.
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25
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Gagnon P, Nian R. Conformational plasticity of IgG during protein A affinity chromatography. J Chromatogr A 2016; 1433:98-105. [DOI: 10.1016/j.chroma.2016.01.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 12/18/2015] [Accepted: 01/09/2016] [Indexed: 10/22/2022]
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26
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Könitzer JD, Sieron A, Wacker A, Enenkel B. Reformatting Rituximab into Human IgG2 and IgG4 Isotypes Dramatically Improves Apoptosis Induction In Vitro. PLoS One 2015; 10:e0145633. [PMID: 26713448 PMCID: PMC4694715 DOI: 10.1371/journal.pone.0145633] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/06/2015] [Indexed: 12/31/2022] Open
Abstract
The direct induction of cell death, or apoptosis, in target cells is one of the effector mechanisms for the anti CD20 antibody Rituximab. Here we provide evidence that Rituximab’s apoptotic ability is linked to the antibody IgG isotype. Reformatting Rituximab from the standard human IgG1 heavy chain into IgG2 or IgG4 boosted in vitro apoptosis induction in the Burkitt’s lymphoma B cell line Ramos five and four-fold respectively. The determinants for this behavior are located in the hinge region and CH1 domain of the heavy chain. By transplanting individual IgG2 or IgG4 specific amino acid residues onto otherwise IgG1 like backbones, thereby creating hybrid antibodies, the same enhancement of apoptosis induction could be achieved. The cysteines at position 131 of the CH1 domain and 219 in the hinge region, involved in IgG2 and IgG4 disulfide formation, were found to be of particular structural importance. Our data indicates that the hybrid antibodies possess a different CD20 binding mode than standard Rituximab, which appears to be key in enhancing apoptotic ability. The presented work opens up an interesting engineering route for enhancing the direct cytotoxic ability of therapeutic antibodies.
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Affiliation(s)
- Jennifer D. Könitzer
- Boehringer Ingelheim, Division Research Germany, Immune Modulation and Biotherapeutics Discovery, Biberach/Riß, Germany
- * E-mail:
| | - Annette Sieron
- Boehringer Ingelheim, Biopharma Operations Germany, Biberach/Riß, Germany
| | - Angelika Wacker
- Boehringer Ingelheim, Bioprocess and Pharmaceutical Development Germany, Biberach/Riß, Germany
| | - Barbara Enenkel
- Boehringer Ingelheim, Bioprocess and Pharmaceutical Development Germany, Biberach/Riß, Germany
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Barnett GV, Qi W, Amin S, Lewis EN, Razinkov VI, Kerwin BA, Liu Y, Roberts CJ. Structural Changes and Aggregation Mechanisms for Anti-Streptavidin IgG1 at Elevated Concentration. J Phys Chem B 2015; 119:15150-63. [PMID: 26563591 DOI: 10.1021/acs.jpcb.5b08748] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Non-native protein aggregation may occur during manufacturing and storage of protein therapeutics, and this may decrease drug efficacy or jeopardize patient safety. From a regulatory perspective, changes in higher order structure due to aggregation are of particular interest but can be difficult to monitor directly at elevated protein concentrations. The present report focuses on non-native aggregation of antistreptavidin (AS) IgG1 at 30 mg/mL under solution conditions that prior work at dilute concentrations (e.g., 1 mg/mL) indicated would result in different aggregation mechanisms. Time-dependent aggregation and structural changes were monitored in situ with dynamic light scattering, small-angle neutron scattering, and Raman scattering and ex situ with far-UV circular dichroism and second-derivative UV spectroscopy. The effects of adding 0.15 M (∼5 w/w %) sucrose were also assessed. The addition of sucrose decreased monomer loss rates but did not change protein-protein interactions, aggregation mechanism(s), or aggregate structure and morphology. Consistent with prior results, altering the pD or salt concentration had the primary effect of changing the aggregation mechanism. Overall, the results provide a comparison of aggregate structure and morphology created via different growth mechanisms using orthogonal techniques and show that the techniques agree at least qualitatively. Interestingly, AS-IgG1 aggregates created at pD 5.3 with no added salt formed the smallest aggregates but had the largest structural changes compared to other solution conditions. The observation that the larger aggregates were also those with less structural perturbation compared to folded AS-IgG1 might be expected to extend to other proteins if the same strong electrostatic repulsions that mediate aggregate growth also mediate structural changes of the constituent proteins within aggregates.
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Affiliation(s)
- Gregory V Barnett
- Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States
| | - Wei Qi
- Malvern Biosciences Incorporated, Columbia, Maryland 21046, United States
| | - Samiul Amin
- Malvern Biosciences Incorporated, Columbia, Maryland 21046, United States
| | - E Neil Lewis
- Malvern Biosciences Incorporated, Columbia, Maryland 21046, United States
| | - Vladimir I Razinkov
- Drug Product Development, Amgen Incorporated, Seattle, Washington 98119, United States
| | - Bruce A Kerwin
- Drug Product Development, Amgen Incorporated, Seattle, Washington 98119, United States
| | - Yun Liu
- Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.,Center for Neutron Science, National Institutes of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Christopher J Roberts
- Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States
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Scapin G, Yang X, Prosise WW, McCoy M, Reichert P, Johnston JM, Kashi RS, Strickland C. Structure of full-length human anti-PD1 therapeutic IgG4 antibody pembrolizumab. Nat Struct Mol Biol 2015; 22:953-8. [DOI: 10.1038/nsmb.3129] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 10/26/2015] [Indexed: 01/18/2023]
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29
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Chenoweth AM, Trist HM, Tan PS, Wines BD, Hogarth PM. The high-affinity receptor for IgG, FcγRI, of humans and non-human primates. Immunol Rev 2015; 268:175-91. [DOI: 10.1111/imr.12366] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Alicia M. Chenoweth
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
| | - Halina M. Trist
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
| | - Peck-Szee Tan
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
| | - Bruce D. Wines
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
- Department of Pathology; University of Melbourne; Melbourne Vic. Australia
| | - P. Mark Hogarth
- Centre for Biomedicine; Burnet Institute; Melbourne Vic. Australia
- Department of Immunology; Monash University; Melbourne Vic. Australia
- Department of Pathology; University of Melbourne; Melbourne Vic. Australia
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The solution structures of native and patient monomeric human IgA1 reveal asymmetric extended structures: implications for function and IgAN disease. Biochem J 2015; 471:167-85. [PMID: 26268558 PMCID: PMC4692083 DOI: 10.1042/bj20150612] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/12/2015] [Indexed: 01/14/2023]
Abstract
Detailed analytical ultracentrifugation and X-ray/neutron scattering data and a new atomistic modelling approach revealed asymmetric extended solution structures for human IgA1 that account for its receptor-binding function. IgA1 with different hinge O-galactosylation patterns showed similar structures. Native IgA1, for which no crystal structure is known, contains an O-galactosylated 23-residue hinge region that joins its Fab and Fc regions. IgA nephropathy (IgAN) is a leading cause of chronic kidney disease in developed countries. Because IgA1 in IgAN often has a poorly O-galactosylated hinge region, the solution structures of monomeric IgA1 from a healthy subject and three IgAN patients with four different O-galactosylation levels were studied. Analytical ultracentrifugation showed that all four IgA1 samples were monomeric with similar sedimentation coefficients, s020,w. X-ray scattering showed that the radius of gyration (Rg) slightly increased with IgA1 concentration, indicating self-association, although their distance distribution curves, P(r), were unchanged with concentration. Neutron scattering indicated similar Rg values and P(r) curves, although IgA1 showed a propensity to aggregate in heavy water buffer. A new atomistic modelling procedure based on comparisons with 177000 conformationally-randomized IgA1 structures with the individual experimental scattering curves revealed similar extended Y-shaped solution structures for all four differentially-glycosylated IgA1 molecules. The final models indicated that the N-glycans at Asn263 were folded back against the Fc surface, the C-terminal tailpiece conformations were undefined and hinge O-galactosylation had little effect on the solution structure. The solution structures for full-length IgA1 showed extended hinges and the Fab and Fc regions were positioned asymmetrically to provide ample space for the functionally-important binding of two FcαR receptors to its Fc region. Whereas no link between O-galactosylation and the IgA1 solution structure was detected, an increase in IgA1 aggregation with reduced O-galactosylation may relate to IgAN.
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Wright DW, Perkins SJ. SCT: a suite of programs for comparing atomistic models with small-angle scattering data. J Appl Crystallogr 2015; 48:953-961. [PMID: 26089768 PMCID: PMC4453981 DOI: 10.1107/s1600576715007062] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 04/08/2015] [Indexed: 12/31/2022] Open
Abstract
Small-angle X-ray and neutron scattering techniques characterize proteins in solution and complement high-resolution structural studies. They are of particular utility when large proteins cannot be crystallized or when the structure is altered by solution conditions. Atomistic models of the averaged structure can be generated through constrained modelling, a technique in which known domain or subunit structures are combined with linker models to produce candidate global conformations. By randomizing the configuration adopted by the different elements of the model, thousands of candidate structures are produced. Next, theoretical scattering curves are generated for each model for trial-and-error fits to the experimental data. From these, a small family of best-fit models is identified. In order to facilitate both the computation of theoretical scattering curves from atomistic models and their comparison with experiment, the SCT suite of tools was developed. SCT also includes programs that provide sequence-based estimates of protein volume (either incorporating hydration or not) and add a hydration layer to models for X-ray scattering modelling. The original SCT software, written in Fortran, resulted in the first atomistic scattering structures to be deposited in the Protein Data Bank, and 77 structures for antibodies, complement proteins and anionic oligosaccharides were determined between 1998 and 2014. For the first time, this software is publicly available, alongside an easier-to-use reimplementation of the same algorithms in Python. Both versions of SCT have been released as open-source software under the Apache 2 license and are available for download from https://github.com/dww100/sct.
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Affiliation(s)
- David W. Wright
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Stephen J. Perkins
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
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Rayner LE, Hui GK, Gor J, Heenan RK, Dalby PA, Perkins SJ. The solution structures of two human IgG1 antibodies show conformational stability and accommodate their C1q and FcγR ligands. J Biol Chem 2015; 290:8420-38. [PMID: 25659433 PMCID: PMC4375494 DOI: 10.1074/jbc.m114.631002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/28/2015] [Indexed: 11/06/2022] Open
Abstract
The human IgG1 antibody subclass shows distinct properties compared with the IgG2, IgG3, and IgG4 subclasses and is the most exploited subclass in therapeutic antibodies. It is the most abundant subclass, has a half-life as long as that of IgG2 and IgG4, binds the FcγR receptor, and activates complement. There is limited structural information on full-length human IgG1 because of the challenges of crystallization. To rectify this, we have studied the solution structures of two human IgG1 6a and 19a monoclonal antibodies in different buffers at different temperatures. Analytical ultracentrifugation showed that both antibodies were predominantly monomeric, with sedimentation coefficients s20,w (0) of 6.3-6.4 S. Only a minor dimer peak was observed, and the amount was not dependent on buffer conditions. Solution scattering showed that the x-ray radius of gyration Rg increased with salt concentration, whereas the neutron Rg values remained unchanged with temperature. The x-ray and neutron distance distribution curves P(r) revealed two peaks, M1 and M2, whose positions were unchanged in different buffers to indicate conformational stability. Constrained atomistic scattering modeling revealed predominantly asymmetric solution structures for both antibodies with extended hinge structures. Both structures were similar to the only known crystal structure of full-length human IgG1. The Fab conformations in both structures were suitably positioned to permit the Fc region to bind readily to its FcγR and C1q ligands without steric clashes, unlike human IgG4. Our molecular models for human IgG1 explain its immune activities, and we discuss its stability and function for therapeutic applications.
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Affiliation(s)
- Lucy E Rayner
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Gar Kay Hui
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Jayesh Gor
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Richard K Heenan
- the ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom, and
| | - Paul A Dalby
- the Department of Biochemical Engineering, Division of Engineering, Roberts Building, University College London, Gower Street, London WC1E 7JE, United Kingdom
| | - Stephen J Perkins
- From the Department of Structural and Molecular Biology, Division of Biosciences, Darwin Building, University College London, Gower Street, London WC1E 6BT, United Kingdom,
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Twa DDW, Steidl C. Structural genomic alterations in primary mediastinal large B-cell lymphoma. Leuk Lymphoma 2015; 56:2239-50. [DOI: 10.3109/10428194.2014.985673] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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