1
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Kim SC, Wakwe W, Higginbotham LB, Mathews DV, Breeden CP, Stephenson AC, Jenkins J, Strobert E, Price K, Price L, Kuhn R, Wang H, Yamniuk A, Suchard S, Farris AB, Pearson TC, Larsen CP, Ford ML, Suri A, Nadler S, Adams AB. Fc-Silent Anti-CD154 Domain Antibody Effectively Prevents Nonhuman Primate Renal Allograft Rejection. Am J Transplant 2017; 17:1182-1192. [PMID: 28097811 PMCID: PMC5409881 DOI: 10.1111/ajt.14197] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 01/25/2023]
Abstract
The advent of costimulation blockade provides the prospect for targeted therapy with improved graft survival in transplant patients. Perhaps the most effective costimulation blockade in experimental models is the use of reagents to block the CD40/CD154 pathway. Unfortunately, successful clinical translation of anti-CD154 therapy has not been achieved. In an attempt to develop an agent that is as effective as previous CD154 blocking antibodies but lacks the risk of thromboembolism, we evaluated the efficacy and safety of a novel anti-human CD154 domain antibody (dAb, BMS-986004). The anti-CD154 dAb effectively blocked CD40-CD154 interactions but lacked crystallizable fragment (Fc) binding activity and resultant platelet activation. In a nonhuman primate kidney transplant model, anti-CD154 dAb was safe and efficacious, significantly prolonging allograft survival without evidence of thromboembolism (Median survival time 103 days). The combination of anti-CD154 dAb and conventional immunosuppression synergized to effectively control allograft rejection (Median survival time 397 days). Furthermore, anti-CD154 dAb treatment increased the frequency of CD4+ CD25+ Foxp3+ regulatory T cells. This study demonstrates that the use of a novel anti-CD154 dAb that lacks Fc binding activity is safe without evidence of thromboembolism and is equally as potent as previous anti-CD154 agents at prolonging renal allograft survival in a nonhuman primate preclinical model.
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Affiliation(s)
- Steven C Kim
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Walter Wakwe
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Laura B Higginbotham
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - David V Mathews
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Cynthia P Breeden
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Allison C Stephenson
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Joe Jenkins
- Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, GA, USA
| | - Elizabeth Strobert
- Yerkes National Primate Research Center, School of Medicine, Emory University, Atlanta, GA, USA
| | - Karen Price
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Laura Price
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Robert Kuhn
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Haiqing Wang
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Aaron Yamniuk
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Suzanne Suchard
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Alton B Farris
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Thomas C Pearson
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Christian P Larsen
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Mandy L Ford
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
| | - Anish Suri
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Steven Nadler
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, NJ, USA
| | - Andrew B Adams
- Emory Transplant Center, Department of Surgery, School of Medicine, Emory University, Atlanta, GA, USA
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2
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Quast I, Peschke B, Lünemann JD. Regulation of antibody effector functions through IgG Fc N-glycosylation. Cell Mol Life Sci 2017; 74:837-847. [PMID: 27639381 PMCID: PMC11107549 DOI: 10.1007/s00018-016-2366-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/05/2016] [Accepted: 09/13/2016] [Indexed: 02/03/2023]
Abstract
Immunoglobulin gamma (IgG) antibodies are key effector proteins of the immune system. They recognize antigens with high specificity and are indispensable for immunological memory following pathogen exposure or vaccination. The constant, crystallizable fragment (Fc) of IgG molecules mediates antibody effector functions such as complement-dependent cytotoxicity, antibody-mediated cellular cytotoxicity, and antibody-dependent cell-mediated phagocytosis. These functions are regulated by a single N-linked, biantennary glycan of the heavy chain, which resides just below the hinge region, and the presence of specific sugar moieties on the glycan has profound implications on IgG effector functions. Emerging knowledge of how Fc glycans contribute to IgG structure and functions has opened new avenues for the therapeutic exploitation of defined antibody glycoforms in the treatment of cancer and autoimmune diseases. Here, we review recent advances in understanding proinflammatory IgG effector functions and their regulation by Fc glycans.
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Affiliation(s)
- Isaak Quast
- Laboratory of Neuroinflammation, Department of Neuroinflammation, Institute of Experimental Immunology, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Benjamin Peschke
- Laboratory of Neuroinflammation, Department of Neuroinflammation, Institute of Experimental Immunology, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Jan D Lünemann
- Laboratory of Neuroinflammation, Department of Neuroinflammation, Institute of Experimental Immunology, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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3
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Hayes JM, Wormald MR, Rudd PM, Davey GP. Fc gamma receptors: glycobiology and therapeutic prospects. J Inflamm Res 2016; 9:209-219. [PMID: 27895507 PMCID: PMC5118039 DOI: 10.2147/jir.s121233] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Therapeutic antibodies hold great promise for the treatment of cancer and autoimmune diseases, and developments in antibody–drug conjugates and bispecific antibodies continue to enhance treatment options for patients. Immunoglobulin (Ig) G antibodies are proteins with complex modifications, which have a significant impact on their function. The most important of these modifications is glycosylation, the addition of conserved glycans to the antibody Fc region, which is critical for its interaction with the immune system and induction of effector activities such as antibody-dependent cell cytotoxicity, complement activation and phagocytosis. Communication of IgG antibodies with the immune system is controlled and mediated by Fc gamma receptors (FcγRs), membrane-bound proteins, which relay the information sensed and gathered by antibodies to the immune system. These receptors are also glycoproteins and provide a link between the innate and adaptive immune systems. Recent information suggests that this receptor glycan modification is also important for the interaction with antibodies and downstream immune response. In this study, the current knowledge on FcγR glycosylation is discussed, and some insight into its role and influence on the interaction properties with IgG, particularly in the context of biotherapeutics, is provided. For the purpose of this study, other Fc receptors such as FcαR, FcεR or FcRn are not discussed extensively, as IgG-based antibodies are currently the only therapeutic antibody-based products on the market. In addition, FcγRs as therapeutics and therapeutic targets are discussed, and insight into and comment on the therapeutic aspects of receptor glycosylation are provided.
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Affiliation(s)
- Jerrard M Hayes
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
| | - Mark R Wormald
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, UK
| | - Pauline M Rudd
- NIBRT Glycoscience Group, National Institute for Bioprocessing, Research and Training, Dublin, Ireland
| | - Gavin P Davey
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
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4
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Geuijen KPM, Egging DF, Bartels S, Schouten J, Schasfoort RB, Eppink MH. Characterization of low affinity Fcγ receptor biotinylation under controlled reaction conditions by mass spectrometry and ligand binding analysis. Protein Sci 2016; 25:1841-52. [PMID: 27479529 DOI: 10.1002/pro.2994] [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] [Received: 04/25/2016] [Accepted: 07/08/2016] [Indexed: 12/12/2022]
Abstract
Chemical protein biotinylation and streptavidin or anti-biotin-based capture is regularly used for proteins as a more controlled alternative to direct coupling of the protein on a biosensor surface. On biotinylation an interaction site of interest may be blocked by the biotin groups, diminishing apparent activity of the protein. Minimal biotinylation can circumvent the loss of apparent activity, but still a binding site of interest can be blocked when labeling an amino acid involved in the binding. Here, we describe reaction condition optimization studies for minimal labeling. We have chosen low affinity Fcγ receptors as model compounds as these proteins contain many lysines in their active binding site and as such provide an interesting system for a minimal labeling approach. We were able to identify the most critical parameters (protein:biotin ratio and incubation pH) for a minimal labeling approach in which the proteins of choice remain most active toward analyte binding. Localization of biotinylation by mass spectrometric peptide mapping on minimally labeled material was correlated to protein activity in binding assays. We show that only aiming at minimal labeling is not sufficient to maintain an active protein. Careful fine-tuning of critical parameters is important to reduce biotinylation in a protein binding site.
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Affiliation(s)
- Karin P M Geuijen
- Downstream Processing, Synthon Biopharmaceuticals, BV, 6503, GN Nijmegen, The Netherlands. .,Bioprocess Engineering, Wageningen University, 6700 AA, Wageningen, The Netherlands.
| | - David F Egging
- Preclinical Department, Synthon Biopharmaceuticals, BV, 6503, GN Nijmegen, The Netherlands
| | - Stefanie Bartels
- Upstream Processing, Synthon Biopharmaceuticals, BV, 6503, GN Nijmegen, The Netherlands
| | - Jan Schouten
- Upstream Processing, Synthon Biopharmaceuticals, BV, 6503, GN Nijmegen, The Netherlands
| | - Richard B Schasfoort
- Medical Cell Biophysics group, MIRA institute, Faculty of Science and Technology, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Michel H Eppink
- Downstream Processing, Synthon Biopharmaceuticals, BV, 6503, GN Nijmegen, The Netherlands.,Bioprocess Engineering, Wageningen University, 6700 AA, Wageningen, The Netherlands
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5
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The FcγR/IgG Interaction as Target for the Treatment of Autoimmune Diseases. J Clin Immunol 2016; 36 Suppl 1:95-9. [DOI: 10.1007/s10875-016-0272-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 01/05/2023]
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6
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Hanson QM, Barb AW. A perspective on the structure and receptor binding properties of immunoglobulin G Fc. Biochemistry 2015; 54:2931-42. [PMID: 25926001 DOI: 10.1021/acs.biochem.5b00299] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Recombinant antibodies spurred a revolution in medicine that saw the introduction of powerful therapeutics for treating a wide range of diseases, from cancers to autoimmune disorders and transplant rejection, with more applications looming on the horizon. Many of these therapeutic monoclonal antibodies (mAbs) are based on human immunoglobulin G1 (IgG1) or contain at least a portion of the molecule. Most mAbs require interactions with cell surface receptors for efficacy, including the Fc γ receptors. High-resolution structural models of antibodies and antibody fragments have been available for nearly 40 years; however, a thorough description of the structural features that determine the affinity with which antibodies interact with human receptors has not been published. In this review, we will cover the relevant history of IgG-related literature and how recent developments have changed our view of critical antibody-cell interactions at the atomic level with a nod to outstanding questions in the field and future prospects.
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Affiliation(s)
- Quinlin M Hanson
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, Iowa 50011, United States
| | - Adam W Barb
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, Iowa 50011, United States
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7
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Kovalitskaya YA, Navolotskaya EV. Nonopioid effect of β-endorphin. BIOCHEMISTRY (MOSCOW) 2011; 76:379-93. [PMID: 21585314 DOI: 10.1134/s0006297911040018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This review presents the generalized literature data and the results of our own research of the nonopioid effect of β-endorphin, an opioid neuropeptide interacting not only with opioid but also with nonopioid (insensitive to the opioid antagonist naloxone) receptors. The roles of the hormone and its receptors in regulation of the immune, nervous, and endocrine systems are discussed. The effect of neuromediator on the immune system mediated by both opioid and nonopioid receptors is considered in detail. The data on distribution and function of the nonopioid β-endorphin receptor in human and animal organisms are presented. All available data on the characteristics of the nonopioid β-endorphin receptor obtained by means of radioligand analysis are given. The discussed information is supposed to extend our conceptions of the role of β-endorphin in mammals and to be of extensive use in medicine and pharmacology.
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Affiliation(s)
- Yu A Kovalitskaya
- Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
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8
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Machino Y, Ohta H, Suzuki E, Higurashi S, Tezuka T, Nagashima H, Kohroki J, Masuho Y. Effect of immunoglobulin G (IgG) interchain disulfide bond cleavage on efficacy of intravenous immunoglobulin for immune thrombocytopenic purpura (ITP). Clin Exp Immunol 2010; 162:415-24. [PMID: 21029072 DOI: 10.1111/j.1365-2249.2010.04255.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Intravenous immunoglobulin (IVIG) has been used widely to treat immune thrombocytopenic purpura (ITP), but the mechanisms of its action remain unclear. We investigated the affinity for Fcγ receptors (FcγRs) and the thrombocytopenia-ameliorating effect of S-sulfonated gammaglobulin (SGG) and S-alkylated gammaglobulin (AGG), in comparison with unmodified gammaglobulin (GG), in a mouse ITP model. Cleavage of immunoglobulin (Ig)G interchain disulfide bonds by either S-sulfonation or S-alkylation did not decrease the affinity for FcγRIIA (CD32A) and FcγRIIB (CD32B), but did decrease the affinity for FcγRIA (CD64A) and FcγRIIIA (CD16A), presumably because of changes in H-chain configuration. The interchain disulfide bond cleavage decreased the affinity much more for mouse FcγRIV than for mouse FcγRIIB. The ability of AGG to ameliorate ITP was greatly diminished, while SGG, whose disulfide bonds are reconstituted in vivo, was as effective as GG. These results suggest that the interchain disulfide bonds are important for therapeutic effect. It is also suggested that the interaction of IVIG with the inhibitory receptor FcγRIIB is insufficient for effective amelioration of ITP and that, at least in this model, direct binding of IVIG to FcγRIIIA is also required.
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Affiliation(s)
- Y Machino
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
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9
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Kovalitskaya YA, Navolotskaya EV. Synthetic peptide immunorphin as an instrument of the study of nonopioid β-endorphin receptor. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010. [DOI: 10.1134/s106816201001005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Berntzen G, Andersen JT, Ustgård K, Michaelsen TE, Mousavi SA, Qian JD, Kristiansen PE, Lauvrak V, Sandlie I. Identification of a high affinity FcgammaRIIA-binding peptide that distinguishes FcgammaRIIA from FcgammaRIIB and exploits FcgammaRIIA-mediated phagocytosis and degradation. J Biol Chem 2008; 284:1126-35. [PMID: 18957413 DOI: 10.1074/jbc.m803584200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FcgammaRIIA is a key activating receptor linking immune complex formation with cellular effector functions. FcgammaRIIA has 93% identity with an inhibitory receptor, FcgammaRIIB, which negatively regulates FcgammaRIIA. FcgammaRIIA is important in the therapeutic action of several monoclonal antibodies. Binding molecules that discriminate FcgammaRIIA from FcgammaRIIB may optimize receptor activity and serve as a lead for development of therapeutics with FcgammaRIIA as a key target. Here we report the use of phage display libraries to select short peptides with distinct FcgammaRIIA binding properties. An 11-mer peptide (WAWVWLTETAV) was characterized that bound FcgammaRIIA with a K(d) of 500 nm. It mediated cell internalization and degradation of a model antigen. The peptide-binding site on FcgammaRIIA was shown to involve Phe(163) and the IgG binding amino acids Trp(90) and Trp(113). It is thus overlapping but not identical to that of IgG. Neither activating receptors FcgammaRI and FcgammaRIII, nor FcgammaRIIB, all of which lack Phe(163), bound the peptide.
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Affiliation(s)
- Gøril Berntzen
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
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11
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Ellsworth JL, Maurer M, Harder B, Hamacher N, Lantry M, Lewis KB, Rene S, Byrnes-Blake K, Underwood S, Waggie KS, Visich J, Lewis KE. Targeting immune complex-mediated hypersensitivity with recombinant soluble human FcgammaRIA (CD64A). THE JOURNAL OF IMMUNOLOGY 2008; 180:580-9. [PMID: 18097060 DOI: 10.4049/jimmunol.180.1.580] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Binding of Ag-Ab immune complexes to cellular FcgammaR promotes cell activation, release of inflammatory mediators, and tissue destruction characteristic of autoimmune disease. To evaluate whether a soluble FcgammaR could block the proinflammatory effects of immune complexes, recombinant human (rh) versions of FcgammaRIA, FcgammaRIIA, and FcgammaRIIIA were prepared. Binding of rh-FcgammaRIA to IgG was of high affinity (KD=1.7x10(-10) M), whereas rh-FcgammaRIIA and rh-FcgammaRIIIA bound with low affinity (KD=0.6-1.9x10(-6) M). All rh-FcgammaR reduced immune complex precipitation, blocked complement-mediated lysis of Ab-sensitized RBC, and inhibited immune complex-mediated production of IL-6, IL-13, MCP-1, and TNF-alpha by cultured mast cells. Local or systemic delivery only of rh-FcgammaRIA, however, reduced edema and neutrophil infiltration in the cutaneous Arthus reaction in mice. 125I-labeled rh-FcgammaRIA was cleared from mouse blood with a rapid distribution phase followed by a slow elimination phase with a t1/2gamma of approximately 130 h. The highest percentage of injected radioactivity accumulated in blood approximately liver approximately carcass>kidney. s.c. dosing of rh-FcgammaRIA resulted in lower serum levels of inflammatory cytokines and prevented paw swelling and joint damage in a murine model of collagen Ab-induced arthritis. These data demonstrate that rh-FcgammaRIA is an effective inhibitor of type III hypersensitivity.
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Affiliation(s)
- Jeff L Ellsworth
- Department of Autoimmunity and Inflammation, ZymoGenetics, Seattle, WA 98102, USA.
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12
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Li P, Jiang N, Nagarajan S, Wohlhueter R, Selvaraj P, Zhu C. Affinity and kinetic analysis of Fcgamma receptor IIIa (CD16a) binding to IgG ligands. J Biol Chem 2007; 282:6210-21. [PMID: 17202140 DOI: 10.1074/jbc.m609064200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Binding of pathogen-bound immunoglobulin G (IgG) to cell surface Fc gamma receptors (FcgammaRs) triggers a wide variety of effector functions. The binding kinetics and affinities of IgG-FcgammaR interactions are hence important parameters for understanding FcgammaR-mediated immune functions. We have measured the kinetic rates and equilibrium dissociation constants of IgG binding to a soluble FcgammaRIIIa fused with Ig Fc (sCD16a) using the surface plasmon resonance technique. sCD16a interacted with monomeric human IgG and its subtypes IgG1 and IgG3 as well as rabbit IgG with on-rates of 6.5 x 10(3), 8.2 x 10(3), 1.1 x 10(4) and 1.8 x 10(4) m(-1) s(-1), off-rates of 4.7 x 10(-3), 5.7 x 10(-3), 5.9 x 10(-3), and 1.9 x 10(-2) s(-1), and equilibrium dissociation constants of 0.72, 0.71, 0.56, and 1.1 mum, respectively. The kinetics and affinities measured by surface plasmon resonance agreed with those obtained from real time flow cytometry and competition inhibition binding experiments using cell surface CD16a. These data add to our understanding of IgG-FcgammaR interactions.
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Affiliation(s)
- Ping Li
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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13
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Takizawa T, Anderson CL, Robinson JM. A Novel FcγR-Defined, IgG-Containing Organelle in Placental Endothelium. THE JOURNAL OF IMMUNOLOGY 2005; 175:2331-9. [PMID: 16081803 DOI: 10.4049/jimmunol.175.4.2331] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Placental transfer of IgG from maternal circulation to that of the fetus is crucial for fetal and newborn immunity. This process requires that IgG broach two cellular layers of the placenta. IgG transport across the first layer, the syncytiotrophoblast, is almost certainly mediated by the MHC-related FcR for IgG, FcRn. The second layer, the villus endothelium, was until recently thought to allow IgG movement nonspecifically by constitutive transcytosis in caveolae. However, we recently showed that villus endothelium expressed a separate FcR for IgG, the inhibitory motif-bearing Fc gammaRIIb2 seen most notably on macrophages and as a minor fraction of the Fc gammaRIIb expressed on B cells. Now, by quantitative microscopy, we find Fc gammaRIIb2 to be expressed abundantly in an unidentifiable and likely novel organelle of the villus endothelium, unassociated with caveolae. About half of these Fc gammaRIIb2 organelles contain IgG; the remainder lack IgG. The majority fraction (approximately 80%) of IgG-containing organelles is associated with Fc gammaRIIb. No IgG-containing organelles are associated with caveolin. These findings are compatible with Fc gammaRIIb-mediated transfer of IgG across the villus endothelium, independent of caveolae.
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MESH Headings
- Animals
- Antibody Specificity
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, CD/physiology
- Caveolae/chemistry
- Caveolae/immunology
- Caveolae/metabolism
- Caveolae/ultrastructure
- Caveolin 1/metabolism
- Cell Line
- Chorionic Villi/blood supply
- Chorionic Villi/chemistry
- Chorionic Villi/immunology
- Chorionic Villi/ultrastructure
- Cryoelectron Microscopy
- Endothelium, Vascular/chemistry
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/ultrastructure
- Fluorescent Antibody Technique
- Genes, Overlapping
- Histocompatibility Antigens Class I/metabolism
- Immunoglobulin G/genetics
- Immunoglobulin G/metabolism
- Microscopy, Immunoelectron
- Organelles/chemistry
- Organelles/immunology
- Organelles/metabolism
- Organelles/ultrastructure
- Pregnancy Proteins/biosynthesis
- Pregnancy Proteins/genetics
- Pregnancy Proteins/metabolism
- Pregnancy Proteins/physiology
- Receptors, Fc/metabolism
- Receptors, IgG/biosynthesis
- Receptors, IgG/genetics
- Receptors, IgG/metabolism
- Receptors, IgG/physiology
- Subcellular Fractions/chemistry
- Subcellular Fractions/immunology
- Subcellular Fractions/metabolism
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Affiliation(s)
- Toshihiro Takizawa
- Department of Physiology and Cell Biology, Ohio State University, Columbus 43210, USA
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14
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Nimmerjahn F, Bruhns P, Horiuchi K, Ravetch JV. FcγRIV: A Novel FcR with Distinct IgG Subclass Specificity. Immunity 2005; 23:41-51. [PMID: 16039578 DOI: 10.1016/j.immuni.2005.05.010] [Citation(s) in RCA: 524] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 05/04/2005] [Accepted: 05/11/2005] [Indexed: 01/20/2023]
Abstract
Mouse IgG subclasses display a hierarchy of in vivo activities, with IgG2a and IgG2b showing the greatest protective and pathogenic properties. These enhanced activities result, in part, from their ability to bind to a novel, gamma chain-dependent, activating IgG Fc receptor, FcgammaRIV. FcgammaRIV maps in the 75 kb genomic interval between FcgammaRII and FcgammaRIII; its expression is restricted to myeloid lineage cells, and it binds to IgG2a and IgG2b with intermediate affinity. No binding to IgG1 or IgG3 was observed. Blocking FcgammaRIV binding to pathogenic anti-platelet antibodies is sufficient to protect mice from antibody-induced thrombocytopenia. Thus, the FcgammaR system has evolved distinct activation receptors displaying selectivity for IgG subclasses, with IgG1 antibodies exclusively dependent on FcgammaRIII, whereas IgG2a and IgG2b show preferential dependence on FcgammaRIV activation. These distinct binding affinities for the IgG subclasses to FcgammaRs account for their differential protective and pathogenic activities in vivo.
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Affiliation(s)
- Falk Nimmerjahn
- Laboratory of Molecular Genetics and Immunology, The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA
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15
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Hart SP, Alexander KM, Dransfield I. Immune Complexes Bind Preferentially to FcγRIIA (CD32) on Apoptotic Neutrophils, Leading to Augmented Phagocytosis by Macrophages and Release of Proinflammatory Cytokines. THE JOURNAL OF IMMUNOLOGY 2004; 172:1882-7. [PMID: 14734773 DOI: 10.4049/jimmunol.172.3.1882] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many human inflammatory diseases are associated with tissue deposition of immune complexes and influx of neutrophils. We show that immune complexes bind preferentially to apoptotic neutrophils via FcgammaRIIA (CD32) and that increased binding is associated with clustering of immune complexes on the plasma membrane of the apoptotic cell. Phagocytosis of immune complex-opsonized apoptotic neutrophils by human macrophages was substantially enhanced (4.4-fold increase compared with control apoptotic neutrophils) and stimulated macrophages to release the proinflammatory cytokines TNF-alpha and IL-6. Immune complexes may perturb the normal pathways for clearance of apoptotic neutrophils by augmenting their clearance at the price of proinflammatory cytokine release. This represents a novel mechanism by which immune complexes may modulate the resolution of inflammation.
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Affiliation(s)
- Simon P Hart
- Medical Research Council Center for Inflammation Research, University of Edinburgh Medical School, Edinburgh, United Kingdom.
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16
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Sondermann P, Oosthuizen V. The structure of Fc receptor/Ig complexes: considerations on stoichiometry and potential inhibitors. Immunol Lett 2002; 82:51-6. [PMID: 12008034 DOI: 10.1016/s0165-2478(02)00018-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recently, Fc receptors for immunoglobulins moved further into the focus of pure and applied research as a role in the induction and development of autoimmune diseases and allergies is becoming more probable. Indeed by connecting the humoral with the cellular immune response FcRs possess an important role in the immune system in which the initial, crucial step is the binding of an immunoglobulin to the cell bound receptor. Thereafter a variety of effector functions depending on the cell and the receptor is triggered. This key event could recently be visualised with the solution of the crystal structure of a human Fc receptor in complex with its native ligand the Fc fragment of IgG1. In this paper the reasons for a 1:1 stoichiometry between Fc receptor and Fc Fragment and the medical applications of potential inhibitors of complex formation are highlighted.
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Affiliation(s)
- Peter Sondermann
- Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, Martinsried, Germany.
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17
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Ramachandran R, Hartmann C, Song HK, Huber R, Bochtler M. Functional interactions of HslV (ClpQ) with the ATPase HslU (ClpY). Proc Natl Acad Sci U S A 2002; 99:7396-401. [PMID: 12032294 PMCID: PMC124242 DOI: 10.1073/pnas.102188799] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2002] [Indexed: 11/18/2022] Open
Abstract
HslVU is a bacterial homolog of the proteasome, where HslV is the protease that is activated by HslU, an ATPase and chaperone. Structures of singly and doubly capped HslVU particles have been reported, and different binding modes have been observed. Even among HslVU structures with I-domains distal to HslV, no consensus mode of activation has emerged. A feature in the Haemophilus influenzae HslVU structure, insertion of the C termini of HslU into pockets in HslV, was not seen in all other structures of the enzyme. Here we report site-directed mutagenesis, peptide activation, and fluorescence experiments that strongly support the functional relevance of the C terminus insertion mechanism: we find that mutations in HslV that disrupt the interaction with the C termini of HslU invariably lead to inactive enzyme. Conversely, synthetic peptides derived from the C terminus of HslU bind to HslV with 10(-5) M affinity and can functionally replace full HslU particles for both peptide and casein degradation but fail to support degradation of a folded substrate. Thus, the data can be taken as evidence for separate substrate unfoldase and protease stimulation activities in HslU. Enhanced HslV proteolysis could be due to the opening of a gated channel or allosteric activation of the active sites. To distinguish between these possibilities, we have mutated a series of residues that line the entrance channel into the HslV particle. Our mutational and fluorescence experiments demonstrate that allosteric activation of the catalytic sites is required in HslV, but they do not exclude the possibility of channel opening taking place as well. The present data support the conclusion that the H. influenzae structure with I-domains distal to HslV captures the active species and point to significant differences in the activation mechanism of HslV, ClpP, and the proteasome.
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Affiliation(s)
- Ravishankar Ramachandran
- Abteilung Strukturforschung, Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Planegg-Martinsried, Germany
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18
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Chapter 22. Fc receptor structure and the design of anti-inflammatories: New therapeutics for autoimmune disease. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2002. [DOI: 10.1016/s0065-7743(02)37023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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19
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Maenaka K, van der Merwe PA, Stuart DI, Jones EY, Sondermann P. The human low affinity Fcgamma receptors IIa, IIb, and III bind IgG with fast kinetics and distinct thermodynamic properties. J Biol Chem 2001; 276:44898-904. [PMID: 11544262 DOI: 10.1074/jbc.m106819200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fcgamma receptors (FcgammaRs) are expressed on all immunologically active cells. They bind the Fc portion of IgG, thereby triggering a range of immunological functions. We have used surface plasmon resonance to analyze the kinetic and thermodynamic properties of the interactions between the ectodomains of human low affinity FcgammaRs (FcgammaRIIa, FcgammaRIIb, and FcgammaRIIIb-NA2) and IgG1 or the Fc fragment of IgG1. All three receptors bind Fc or IgG with similarly low affinities (K(D) approximately 0.6-2.5 microm) and fast kinetics, suggesting that FcgammaR-mediated recognition of aggregated IgG and IgG-coated particles or cells is mechanistically similar to cell-cell recognition. Interestingly, the Fc receptors exhibit distinct thermodynamic properties. Whereas the binding of the FcgammaRIIa and FcgammaRIIb to Fc is driven by favorable entropic and enthalpic changes, the binding of FcgammaRIII is characterized by highly unfavorable entropic changes. Although the structural bases for these differences remain to be determined, they suggest that the molecular events coupled to the binding differ among the low affinity FcgammaRs.
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Affiliation(s)
- K Maenaka
- Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.
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20
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Sondermann P, Kaiser J, Jacob U. Molecular basis for immune complex recognition: a comparison of Fc-receptor structures. J Mol Biol 2001; 309:737-49. [PMID: 11397093 DOI: 10.1006/jmbi.2001.4670] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Once antigen is opsonised by IgG it is removed from the circulation by Fcgamma-receptor expressing cells. Fcgamma-receptors are type I transmembrane molecules that carry extracellular parts consisting of two or three immunoglobulin domains. Previously solved structures of Fc-receptors reveal that the N-terminal two Ig-like domains are arranged in a steep angle forming a heart-shaped structure. The crystal structure of the FcgammaRIII/hIgG1-Fc-fragment demonstrated that the Fc-fragment is recognised through loops of the C-terminal receptor domain of the FcgammaRIII. As the overall structure of the FcRs and their Ig ligands are very similar we modelled the Ig complexes with FcgammaRI, FcgammaRII and FcepsilonRIalpha based on the FcgammaRIII/hIgG1-Fc-fragment structure. The obtained models are consistent with the observed biochemical data and may explain the observed specificity and affinities.
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Affiliation(s)
- P Sondermann
- Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, Martinsried, D-82152, Germany.
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21
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Kato K. [Structural basis of the interaction between immunoglobulins and Fc receptors provided by NMR spectroscopy]. YAKUGAKU ZASSHI 2001; 121:345-54. [PMID: 11360488 DOI: 10.1248/yakushi.121.345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fc gamma Receptors (Fc gamma R) are membrane glycoproteins that bind the Fc portion of immunoglobulin G (IgG). The cross linking of Fc gamma R-bound IgG by multivalent antigens allows clustering of the Fc gamma R and initiates a variety of effector mechanisms which play a key role in immune defenses against pathogens. The Fc region is composed of two identical polypeptide chains, which are related to each other by a two-fold axis. Recent elucidation of the crystal structure of human Fc gamma RII provided two distinct views of modes of IgG-Fc gamma R interactions, which is controversial against each other. Nuclear magnetic resonance (NMR) spectroscopy provides a unique and irreplaceable tool to solve these issues. We recently studied the interaction between the Fc fragment of mouse IgG2b and the extracellular domain of mouse Fc gamma RII by this method. We showed that Fc gamma RII binds to a negatively charged area of the CH2 domain, corresponding to the lower hinge region, and that the binding of Fc gamma RII onto one of the two symmetrically related sites on the Fc induces a conformational change in the other site. This conformational change may account for the 1:1 stoichiometry that we and others observed between Fc gamma R and Fc. We therefore propose a model that explains why the interaction between IgG molecules and Fc gamma R does not trigger cellular responses in the absence of cross linking by multivalent antigens and does not lead to spontaneous inflammatory responses that would be deleterious for the organism.
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Affiliation(s)
- K Kato
- Faculty of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
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22
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Lyden TW, Robinson JM, Tridandapani S, Teillaud JL, Garber SA, Osborne JM, Frey J, Budde P, Anderson CL. The Fc receptor for IgG expressed in the villus endothelium of human placenta is Fc gamma RIIb2. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3882-9. [PMID: 11238632 DOI: 10.4049/jimmunol.166.6.3882] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To evaluate the potential role of human placental endothelial cells in the transport of IgG from maternal to fetal circulation, we studied Fc gamma receptor (Fc gamma R) expression by immunohistology and immunoblotting. Several pan-Fc gamma RII Abs that label the placental endothelium displayed a distribution pattern that correlated well with transport functions, being intense in the terminal villus and nil in the cord. In contrast, the MHC class 1-like IgG transporter, FcRn, and the classical Fc gamma RIIa were not expressed in transport-related endothelium of the placenta. Our inference, that Fc gamma RIIb was the likely receptor, we confirmed by analyzing purified placental villi, enriched in endothelium, by immunoblotting with a new Ab specific for the cytoplasmic tail of Fc gamma RIIb. These experiments showed that the Fc gamma RII expressed in villus endothelium was the b2 isoform whose cytoplasmic tail is known to include a phosphotyrosyl-based motif that inhibits a variety of immune responses. We suggest that this receptor is perfectly positioned to transport IgG although as well it may scavenge immune complexes.
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MESH Headings
- Antibodies, Monoclonal/metabolism
- Antibody Specificity
- Antigens, CD/biosynthesis
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Chorionic Villi/blood supply
- Chorionic Villi/immunology
- Chorionic Villi/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Female
- Glycosylation
- Humans
- Microscopy, Fluorescence
- Pregnancy
- Protein Isoforms/biosynthesis
- Protein Isoforms/immunology
- Protein Isoforms/metabolism
- Receptors, IgG/biosynthesis
- Receptors, IgG/immunology
- Receptors, IgG/metabolism
- Reproducibility of Results
- Tumor Cells, Cultured
- U937 Cells
- Umbilical Cord/blood supply
- Umbilical Cord/immunology
- Umbilical Cord/metabolism
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Affiliation(s)
- T W Lyden
- Department of Internal Medicine, Ohio State University, Columbus, OH 43210, USA
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23
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Wines BD, Sardjono CT, Trist HH, Lay CS, Hogarth PM. The interaction of Fc alpha RI with IgA and its implications for ligand binding by immunoreceptors of the leukocyte receptor cluster. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1781-9. [PMID: 11160224 DOI: 10.4049/jimmunol.166.3.1781] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study defines the molecular basis of the FcalphaRI (CD89):IgA interaction, which is distinct from that of the other leukocyte Fc receptors and their Ig ligands. A comprehensive analysis using both cell-free (biosensor) and cell-based assays was used to define and characterize the IgA binding region of FcalphaRI. Biosensor analysis of mutant FcalphaRI proteins showed that residues Y35, Y81, and R82 were essential for IgA binding, and R52 also contributed. The role of the essential residues (Y35 and R82) was confirmed by analysis of mutant receptors expressed on the surface of mammalian cells. These receptors failed to bind IgA, but were detected by the mAb MY43, which blocks IgA binding to FcalphaRI, indicating that its epitope does not coincide with these IgA binding residues. A homology model of the ectodomains of FcalphaRI was generated based on the structures of killer Ig-like receptors, which share 30-34% identity with FcalphaRI. Key structural features of killer Ig-like receptors are appropriately reproduced in the model, including the structural conservation of the interdomain linker and hydrophobic core (residues V17, V97, and W183). In this FcalphaRI model the residues forming the IgA binding site identified by mutagenesis form a single face near the N-terminus of the receptor, distinct from other leukocyte Fc receptors where ligand binding is in the second domain. This taken together with major differences in kinetics and affinity for IgA:FcalphaRI interaction that were observed depending on whether FcalphaRI was immobilized or in solution suggest a mode of interaction unique among the leukocyte receptors.
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Affiliation(s)
- B D Wines
- The Helen M. Schutt Laboratory for Immunology and Biotechnology, Austin Research Institute, Austin Repatriation Medical Center, Heidelberg, Victoria, Australia
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24
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Zhang Y, Boesen CC, Radaev S, Brooks AG, Fridman WH, Sautes-Fridman C, Sun PD. Crystal structure of the extracellular domain of a human Fc gamma RIII. Immunity 2000; 13:387-95. [PMID: 11021536 DOI: 10.1016/s1074-7613(00)00038-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Fc receptors play a major role in immune defenses against pathogens and in inflammatory processes. The crystal structure of a human immunoglobulin receptor, FcgammaRIIIb, has been determined to 1.8 A resolution. The overall fold consists of two immunoglobulin-like domains with an acute interdomain hinge angle of approximately 50 degrees. Trp-113, wedged between the N-terminal D1 and the C-terminal D2 domains, appears to further restrict the hinge angle. The putative Fc binding region of the receptor carries a net positive charge complementary to the negative-charged receptor binding regions on Fc. A 1:1 binding stoichiometry between the receptor and Fc was measured by both the equilibrium and nonequilibrium size-exclusion chromatography. Two separate parallel dimers are observed in the crystal lattice, offering intriguing models for receptor aggregation.
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Affiliation(s)
- Y Zhang
- Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77555, USA
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25
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Garman SC, Wurzburg BA, Tarchevskaya SS, Kinet JP, Jardetzky TS. Structure of the Fc fragment of human IgE bound to its high-affinity receptor Fc epsilonRI alpha. Nature 2000; 406:259-66. [PMID: 10917520 DOI: 10.1038/35018500] [Citation(s) in RCA: 256] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The initiation of immunoglobulin-E (IgE)-mediated allergic responses requires the binding of IgE antibody to its high-affinity receptor, Fc epsilonRI. Crosslinking of Fc epsilonRI initiates an intracellular signal transduction cascade that triggers the release of mediators of the allergic response. The interaction of the crystallizable fragment (Fc) of IgE (IgE-Fc) with Fc epsilonRI is a key recognition event of this process and involves the extracellular domains of the Fc epsilonRI alpha-chain. To understand the structural basis for this interaction, we have solved the crystal structure of the human IgE-Fc-Fc epsilonRI alpha complex to 3.5-A resolution. The crystal structure reveals that one receptor binds one dimeric IgE-Fc molecule asymmetrically through interactions at two sites, each involving one C epsilon3 domain of the IgE-Fc. The interaction of one receptor with the IgE-Fc blocks the binding of a second receptor, and features of this interaction are conserved in other members of the Fc receptor family. The structure suggests new approaches to inhibiting the binding of IgE to Fc epsilonRI for the treatment of allergy and asthma.
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Affiliation(s)
- S C Garman
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA
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26
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Sondermann P, Huber R, Oosthuizen V, Jacob U. The 3.2-A crystal structure of the human IgG1 Fc fragment-Fc gammaRIII complex. Nature 2000; 406:267-73. [PMID: 10917521 DOI: 10.1038/35018508] [Citation(s) in RCA: 546] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The immune response depends on the binding of opsonized antigens to cellular Fc receptors and the subsequent initiation of various cellular effector functions of the immune system. Here we describe the crystal structures of a soluble Fc gamma receptor (sFc gammaRIII, CD16), an Fc fragment from human IgG1 (hFc1) and their complex. In the 1:1 complex the receptor binds to the two halves of the Fc fragment in contact with residues of the C gamma2 domains and the hinge region. Upon complex formation the angle between the two sFc gammaRIII domains increases significantly and the Fc fragment opens asymmetrically. The high degree of amino acid conservation between sFc gammaRIII and other Fc receptors, and similarly between hFc1 and related immunoglobulins, suggest similar structures and modes of association. Thus the described structure is a model for immune complex recognition and helps to explain the vastly differing affinities of other Fc gammaR-IgG complexes and the Fc epsilonRI alpha-IgE complex.
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Affiliation(s)
- P Sondermann
- Max-Planck-Institut für Biochemie, Martinsried, Germany.
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27
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Kato K, Fridman WH, Arata Y, Sautès-Fridman C. A conformational change in the Fc precludes the binding of two Fcgamma receptor molecules to one IgG. IMMUNOLOGY TODAY 2000; 21:310-2. [PMID: 10871868 DOI: 10.1016/s0167-5699(00)01666-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K Kato
- Faculty of Pharmaceutical Sciences, Nagoya City University, Mizuho-ku, Nagoya 467-8603, Japan
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28
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Masuda K, Yamaguchi Y, Kato K, Takahashi N, Shimada I, Arata Y. Pairing of oligosaccharides in the Fc region of immunoglobulin G. FEBS Lett 2000; 473:349-57. [PMID: 10818239 DOI: 10.1016/s0014-5793(00)01557-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The Fc portion of immunoglobulin G (IgG) expresses paired oligosaccharides with microheterogeneities, which are associated with efficiencies of effector functions and with pathological states. A comparison of electrospray ionization mass spectrometry data obtained using a variety of Fc fragments derived from human and mouse IgG that do and do not retain the inter-chain disulfide bridge(s) revealed that (1) the Fc portion can be asymmetric as well as symmetric with respect to glycosylation and (2) the ratios of the individual glycoforms are different from what is expected from the random pairing.
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Affiliation(s)
- K Masuda
- Suntory Institute for Bioorganic Research, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka, Japan.
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29
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Kato K, Sautès-Fridman C, Yamada W, Kobayashi K, Uchiyama S, Kim H, Enokizono J, Galinha A, Kobayashi Y, Fridman WH, Arata Y, Shimada I. Structural basis of the interaction between IgG and Fcgamma receptors. J Mol Biol 2000; 295:213-24. [PMID: 10623521 DOI: 10.1006/jmbi.1999.3351] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The binding of multivalent antigen-antibody complexes to receptors for the Fc portion of IgG (FcgammaR) induces the clustering of the FcgammaR and triggers cell activation leading to defence reactions against pathogens. The Fc portion of IgG consists of two identical polypeptide chains which are related to each other by a 2-fold axis and are folded in two structural domains, the C(H)2 domain, near the flexible hinge region of the IgG molecule, and the C(H)3 domain. We studied the interaction in solution between the Fc fragment of mouse IgG2b and the extracellular region of mouse FcgammaRII. We find that one Fc molecule binds one FcgammaRII molecule only. Using NMR spectroscopy, we show that FcgammaRII binds to a negatively charged area of the C(H)2 domain, corresponding to the lower hinge region, and that the binding of FcgammaRII onto one of the two symmetrically related sites on the Fc induces a conformational change in the other site. We therefore propose a model that explains why IgG molecules are unable to trigger FcgammaR-mediated cellular responses spontaneously in the absence of crosslinking by multivalent antigens.
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Affiliation(s)
- K Kato
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo Bunkyo-ku, Tokyo, 113-0033, Japan
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