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Strachan E, Clemente-Casares X, Tsai S. Maternal provisions in type 1 diabetes: Evidence for both protective & pathogenic potential. Front Immunol 2023; 14:1146082. [PMID: 37033940 PMCID: PMC10073710 DOI: 10.3389/fimmu.2023.1146082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
Maternal influences on the immune health and development of an infant begin in utero and continue well into the postnatal period, shaping and educating the child's maturing immune system. Two maternal provisions include early microbial colonizers to initiate microbiota establishment and the transfer of antibodies from mother to baby. Maternal antibodies are a result of a lifetime of antigenic experience, reflecting the infection history, health and environmental exposure of the mother. These same factors are strong influencers of the microbiota, inexorably linking the two. Together, these provisions help to educate the developing neonatal immune system and shape lymphocyte repertoires, establishing a role for external environmental influences even before birth. In the context of autoimmunity, the transfer of maternal autoantibodies has the potential to be harmful for the child, sometimes targeting tissues and cells with devastating consequences. Curiously, this does not seem to apply to maternal autoantibody transfer in type 1 diabetes (T1D). Moreover, despite the rising prevalence of the disease, little research has been conducted on the effects of maternal dysbiosis or antibody transfer from an affected mother to her offspring and thus their relevance to disease development in the offspring remains unclear. This review seeks to provide a thorough evaluation of the role of maternal microorganisms and antibodies within the context of T1D, exploring both their pathogenic and protective potential. Although a definitive understanding of their significance in infant T1D development remains elusive at present, we endeavor to present what has been learned with the goal of spurring further interest in this important and intriguing question.
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2
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Mimoun A, Delignat S, Peyron I, Daventure V, Lecerf M, Dimitrov JD, Kaveri SV, Bayry J, Lacroix-Desmazes S. Relevance of the Materno-Fetal Interface for the Induction of Antigen-Specific Immune Tolerance. Front Immunol 2020; 11:810. [PMID: 32477339 PMCID: PMC7240014 DOI: 10.3389/fimmu.2020.00810] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/08/2020] [Indexed: 12/26/2022] Open
Abstract
In humans, maternal IgGs are transferred to the fetus from the second trimester of pregnancy onwards. The transplacental delivery of maternal IgG is mediated by its binding to the neonatal Fc receptor (FcRn) after endocytosis by the syncytiotrophoblast. IgGs present in the maternal milk are also transferred to the newborn through the digestive epithelium upon binding to the FcRn. Importantly, the binding of IgGs to the FcRn is also responsible for the recycling of circulating IgGs that confers them with a long half-life. Maternally delivered IgG provides passive immunity to the newborn, for instance by conferring protective anti-flu or anti-pertussis toxin IgGs. It may, however, lead to the development of autoimmune manifestations when pathological autoantibodies from the mother cross the placenta and reach the circulation of the fetus. In recent years, strategies that exploit the transplacental delivery of antigen/IgG complexes or of Fc-fused proteins have been validated in mouse models of human diseases to impose antigen-specific tolerance, particularly in the case of Fc-fused factor VIII (FVIII) domains in hemophilia A mice or pre-pro-insulin (PPI) in the case of preclinical models of type 1 diabetes (T1D). The present review summarizes the mechanisms underlying the FcRn-mediated transcytosis of IgGs, the physiopathological relevance of this phenomenon, and the repercussion for drug delivery and shaping of the immune system during its ontogeny.
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Affiliation(s)
- Angelina Mimoun
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Sandrine Delignat
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Ivan Peyron
- HITh, INSERM, UMR_S1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Victoria Daventure
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Maxime Lecerf
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Jordan D Dimitrov
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Srinivas V Kaveri
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Jagadeesh Bayry
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
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3
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Cejas RB, Ferguson DC, Quiñones-Lombraña A, Bard JE, Blanco JG. Contribution of DNA methylation to the expression of FCGRT in human liver and myocardium. Sci Rep 2019; 9:8674. [PMID: 31209240 PMCID: PMC6572836 DOI: 10.1038/s41598-019-45203-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/31/2019] [Indexed: 01/05/2023] Open
Abstract
FcRn mediates recycling and transcytosis of IgG and albumin in various cell types. The MHC-class-I-like protein of the FcRn heterodimer is encoded by FCGRT. Few determinants of variable FCGRT expression in humans have been identified so far. In this study, we investigated the presence of DNA methylation in regulatory regions of FCGRT in samples of human liver and myocardium tissue, and we examined the impact of FCGRT methylation on FcRn expression in model cell lines. Quantitative DNA methylation analysis of the FCGRT locus revealed differentially methylated regions in DNA from liver and myocardium. Methylation status in individual CpG sites correlated with FCGRT mRNA expression. Data from model cell lines suggest that differential methylation in the -1058 to -587 bp regulatory region of FCGRT contributes to FcRn expression. Chromatin immunoprecipitation assays indicate that CpG site methylation impacts the binding of the methylation sensitive transcription factors Zbtb7a and Sp1. This study provides a foundation to further define the contribution of epigenetic factors during the control of FcRn expression and IgG traffic in human tissues.
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Affiliation(s)
- R B Cejas
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - D C Ferguson
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - A Quiñones-Lombraña
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - J E Bard
- Genomics and Bioinformatics Core, New York State Center of Excellence in Bioinformatics and Life Sciences, The State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - J G Blanco
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, NY, 14214, USA.
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4
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Huminiecki Ł, Horbańczuk J. Can We Predict Gene Expression by Understanding Proximal Promoter Architecture? Trends Biotechnol 2017; 35:530-546. [PMID: 28377102 DOI: 10.1016/j.tibtech.2017.03.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/14/2017] [Accepted: 03/09/2017] [Indexed: 10/19/2022]
Abstract
We review computational predictions of expression from the promoter architecture - the set of transcription factors that can bind the proximal promoter. We focus on spatial expression patterns in animals with complex body plans and many distinct tissue types. This field is ripe for change as functional genomics datasets accumulate for both expression and protein-DNA interactions. While there has been some success in predicting the breadth of expression (i.e., the fraction of tissue types a gene is expressed in), predicting tissue specificity remains challenging. We discuss how progress can be achieved through either machine learning or complementary combinatorial data mining. The likely impact of single-cell expression data is considered. Finally, we discuss the design of artificial promoters as a practical application.
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Affiliation(s)
- Łukasz Huminiecki
- Institute of Genetics and Animal Breeding, Polish Academy of Sciences, ul. Postępu 36A, Jastrzębiec, 05-552 Magdalenka, Poland.
| | - Jarosław Horbańczuk
- Institute of Genetics and Animal Breeding, Polish Academy of Sciences, ul. Postępu 36A, Jastrzębiec, 05-552 Magdalenka, Poland
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5
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Cervenak J, Kurrle R, Kacskovics I. Accelerating antibody discovery using transgenic animals overexpressing the neonatal Fc receptor as a result of augmented humoral immunity. Immunol Rev 2015; 268:269-87. [DOI: 10.1111/imr.12364] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | | | - Imre Kacskovics
- ImmunoGenes Ltd; Budakeszi Hungary
- Department of Immunology; Eötvös Loránd University; Budapest Hungary
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6
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Mikulska JE. Analysis of Response Elements Involved in the Regulation of the Human Neonatal Fc Receptor Gene (FCGRT). PLoS One 2015; 10:e0135141. [PMID: 26252948 PMCID: PMC4529178 DOI: 10.1371/journal.pone.0135141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/19/2015] [Indexed: 12/26/2022] Open
Abstract
Human epithelial, endothelial and PMA-differentiated THP-1 cell lines were used as model systems to study the transcriptional regulation of the human FCGRT gene encoding the alpha chain of hFcRn. The data obtained from site-directed mutagenesis in transient transfection experiments indicate that the Sp1 sites at positions -641, -635, and -313, CF1/YY1 elements at positions -586 and -357, and the AP-1 motif at -276 within the-660/-233 fragment of the human FCGRT promoter (hFCGRT) participate in the regulation of human FCGRT in all selected cell lines. However, their individual contribution to promoter activity is not equivalent. The Sp1 binding site at -313 and the AP-1 site at -276 are critical for the activity of the hFCGRT promoter in epithelial and endothelial cells. Moreover, the CF1/YY1 site at -586 in differentiated THP-1 cells, plays an essential role in the transcriptional activity of the promoter. In addition, the C/EBPbeta binding site at -497 of the hFCGRT promoter in epithelial and endothelial cells, and the C/EBPbeta motif located at -497 and -233 within the hFCGRT promoter in differentiated THP-1 cells may function as positive regulatory sequences in response to LPS or PMA stimulation. EMSA and supershift analyses showed that the functionally identified binding motifs in the hFCGRT promoter were able to specifically interact with their corresponding (Sp1, Sp2, Sp3, c-Fos, c-Jun, YY1, and C/EBPbeta or C/EBPdelta) transcription factors (TFs), suggesting their possible involvement in the regulation of the human FCGRT gene expression.
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Affiliation(s)
- Joanna E. Mikulska
- Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
- * E-mail:
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7
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Schneider Z, Jani PK, Szikora B, Végh A, Kövesdi D, Iliás A, Cervenak J, Balogh P, Kurucz I, Kacskovics I. Overexpression of Bovine FcRn in Mice Enhances T-Dependent Immune Responses by Amplifying T Helper Cell Frequency and Germinal Center Enlargement in the Spleen. Front Immunol 2015; 6:357. [PMID: 26257730 PMCID: PMC4507463 DOI: 10.3389/fimmu.2015.00357] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 06/30/2015] [Indexed: 11/21/2022] Open
Abstract
The neonatal Fc receptor (FcRn) plays key roles in IgG and albumin homeostasis, maternal IgG transport, and antigen presentation of IgG-opsonized antigens. Previously, we reported that transgenic (Tg) mice that overexpress the bovine FcRn (bFcRn) have augmented T-dependent humoral immune response with increased IgG protection, higher level of antigen-specific antibodies, greater number of antigen-specific B cells, and effective immune response even against weakly immunogenic epitopes. In the current study, we analyzed the localization of the bFcRn in secondary lymphoid organs, and focused to demonstrate the in vivo impact of its overexpression in the spleen on the course of antibody production. bFcRn was highly expressed by red pulp macrophages and marginal zone macrophages in the spleen and by subcapsular sinus macrophages and macrophage-like cells in the interfollicular areas in the lymph node cortex. We also demonstrated that splenic dendritic cells of Tg mice express bFcRn and intraperitoneal immunization of these mice with T-dependent antigens led to more than threefold increase in the number of antigen-specific activated T helper cells with increased size and numbers of germinal centers compared to wild-type controls. bFcRn expression in splenic B cells was also detected and that may also contribute to the enhanced B cell activation. Finally, we demonstrated that these Tg mice developed efficient immune response against very low dose of antigen, reflecting another important practical benefit of these Tg mice.
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Affiliation(s)
- Zita Schneider
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | | | - Bence Szikora
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | - Attila Végh
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary ; ImmunoGenes Kft , Budakeszi , Hungary
| | - Dorottya Kövesdi
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | - Attila Iliás
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary
| | | | - Péter Balogh
- Department of Immunology and Biotechnology, Medical School, University of Pécs , Pécs , Hungary ; Lymphoid Organogenesis Research Group, Szentágothai Research Center, University of Pécs , Pécs , Hungary
| | | | - Imre Kacskovics
- Department of Immunology, Eötvös Loránd University , Budapest , Hungary ; ImmunoGenes Kft , Budakeszi , Hungary
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Cervenak J, Doleschall M, Bender B, Mayer B, Schneider Z, Doleschall Z, Zhao Y, Bősze Z, Hammarström L, Oster W, Kacskovics I. NFκB induces overexpression of bovine FcRn: a novel mechanism that further contributes to the enhanced immune response in genetically modified animals carrying extra copies of FcRn. MAbs 2015; 5:860-71. [PMID: 24492342 DOI: 10.4161/mabs.26507] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Among the many functions of the neonatal Fc receptor (FcRn) for IgG, it binds to IgG-opsonized antigen complexes and propagates their traffic into lysosomes where antigen processing occurs. We previously reported that transgenic (Tg) mice and rabbits that carry multiple copies and overexpress FcRn have augmented humoral immune responses. Nuclear factor-kappa B (NFκB) is a critical molecule in the signaling cascade in the immune response. NFκB induces human FcRn expression and our previous in silico analysis suggested NFκB binding sites in the promoter region of the bovine (b) FcRn α-chain gene (FCGRT). Here, we report the identification of three NFκB transcription binding sites in the promoter region of this gene using luciferase reporter gene technology, electromobility shift assay and supershift analysis. Stimulation of primary bovine endothelial cells with the Toll-like receptor-4 ligand lipopolysaccharide (LPS), which mediates its effect via NFκB, resulted in rapid upregulation of the bFcRn expression and a control gene, bovine E-selectin. This rapid bFcRn gene induction was also observed in the spleen of bFcRn Tg mice treated with intraperitoneally injected LPS, analyzed by northern blot analysis. Finally, NFκB-mediated bFcRn upregulation was confirmed at the protein level in macrophages isolated from the bFcRn Tg mice using flow cytometry with a newly developed FcRn specific monoclonal antibody that does not cross-react with the mouse FcRn. We conclude that NFκB regulates bFcRn expression and thus optimizes its functions, e.g., in the professional antigen presenting cells, and contributes to the much augmented humoral immune response in the bFcRn Tg mice.
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Affiliation(s)
| | - Márton Doleschall
- Molecular Medicine Research Group; Hungarian Academy of Sciences and Semmelweis University; Budapest, Hungary
| | | | - Balázs Mayer
- Department of Dermatology, Venereology, and Dermatooncology; Semmelweis University; Budapest, Hungary
| | - Zita Schneider
- Department of Immunology; Eötvös Loránd University; Budapest, Hungary
| | - Zoltán Doleschall
- Department of Pathogenetics; National Institute of Oncology; Budapest, Hungary
| | - Yaofeng Zhao
- State Key Laboratory of Agrobiotechnology; China Agricultural University; Beijing, China
| | | | - Lennart Hammarström
- Division of Clinical Immunology; Department of Laboratory Medicine; Karolinska Institute at Karolinska University Hospital Huddinge; Stockholm, Sweden
| | | | - Imre Kacskovics
- ImmunoGenes Kft; Budakeszi, Hungary; Department of Immunology; Eötvös Loránd University; Budapest, Hungary
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9
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10
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Pharmacokinetics, pharmacodynamics and physiologically-based pharmacokinetic modelling of monoclonal antibodies. Clin Pharmacokinet 2013; 52:83-124. [PMID: 23299465 DOI: 10.1007/s40262-012-0027-4] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Development of monoclonal antibodies (mAbs) and their functional derivatives represents a growing segment of the development pipeline in the pharmaceutical industry. More than 25 mAbs and derivatives have been approved for a variety of therapeutic applications. In addition, around 500 mAbs and derivatives are currently in different stages of development. mAbs are considered to be large molecule therapeutics (in general, they are 2-3 orders of magnitude larger than small chemical molecule therapeutics), but they are not just big chemicals. These compounds demonstrate much more complex pharmacokinetic and pharmacodynamic behaviour than small molecules. Because of their large size and relatively poor membrane permeability and instability in the conditions of the gastrointestinal tract, parenteral administration is the most usual route of administration. The rate and extent of mAb distribution is very slow and depends on extravasation in tissue, distribution within the particular tissue, and degradation. Elimination primarily happens via catabolism to peptides and amino acids. Although not definitive, work has been published to define the human tissues mainly involved in the elimination of mAbs, and it seems that many cells throughout the body are involved. mAbs can be targeted against many soluble or membrane-bound targets, thus these compounds may act by a variety of mechanisms to achieve their pharmacological effect. mAbs targeting soluble antigen generally exhibit linear elimination, whereas those targeting membrane-bound antigen often exhibit non-linear elimination, mainly due to target-mediated drug disposition (TMDD). The high-affinity interaction of mAbs and their derivatives with the pharmacological target can often result in non-linear pharmacokinetics. Because of species differences (particularly due to differences in target affinity and abundance) in the pharmacokinetics and pharmacodynamics of mAbs, pharmacokinetic/pharmacodynamic modelling of mAbs has been used routinely to expedite the development of mAbs and their derivatives and has been utilized to help in the selection of appropriate dose regimens. Although modelling approaches have helped to explain variability in both pharmacokinetic and pharmacodynamic properties of these drugs, there is a clear need for more complex models to improve understanding of pharmacokinetic processes and pharmacodynamic interactions of mAbs with the immune system. There are different approaches applied to physiologically based pharmacokinetic (PBPK) modelling of mAbs and important differences between the models developed. Some key additional features that need to be accounted for in PBPK models of mAbs are neonatal Fc receptor (FcRn; an important salvage mechanism for antibodies) binding, TMDD and lymph flow. Several models have been described incorporating some or all of these features and the use of PBPK models are expected to expand over the next few years.
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Thorn M, Piche-Nicholas N, Stedman D, Davenport SW, Zhang N, Collinge M, Bowman CJ. Embryo-fetal transfer of bevacizumab (Avastin) in the rat over the course of gestation and the impact of neonatal Fc receptor (FcRn) binding. ACTA ACUST UNITED AC 2012; 95:363-75. [PMID: 22969064 DOI: 10.1002/bdrb.21026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 08/21/2012] [Indexed: 01/06/2023]
Abstract
BACKGROUND There is concern about embryo-fetal exposure to antibody-based biopharmaceuticals based on the increase of such therapies being prescribed to women of childbearing potential. Therefore, there is a desire to better characterize embryo-fetal exposure of these molecules. The pregnant rat is a standard model for evaluating the potential consequences of exposure but placental transfer of antibody-based biopharmaceuticals is not well understood in this model. METHODS The relative embryo-fetal distribution of an antibody-based biopharmaceutical was evaluated in the rat. Bevacizumab (Avastin) was chosen as a tool antibody since it does not have significant target binding in the rat that might influence embryo-fetal biodistribution. Avastin was labeled with a fluorescent dye, characterized, and injected into pregnant rats at different gestation ages. Labeled Avastin in fetal tissues was visualized ex vivo using an IVIS 200 (Caliper, A PerkinElmer Company, Alameda, CA). RESULTS Avastin localized to the fetus as early as 24-hr post intravenous injection of the dam, and was taken up by the fetus in a dose-dependent manner. Avastin was detectable in the developing embryo as early as gestation day 13 and continued to be transferred until the end of gestation. Fetal transfer of Avastins mutated in the portion of the antibody that binds the neonatal Fc receptor (FcRn) was tested in late gestation and was found to correlate with affinities of the mutant Avastin antibody to FcRn. CONCLUSIONS The novel application of this imaging technology was used to characterize the onset and duration of Avastin maternal-fetal transfer in rats and the importance of FcRn binding.
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Affiliation(s)
- Mitchell Thorn
- Drug Safety Research & Development, Pfizer, Inc., Groton, CT 06340, USA
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12
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Kuo TT, Baker K, Yoshida M, Qiao SW, Aveson VG, Lencer WI, Blumberg RS. Neonatal Fc receptor: from immunity to therapeutics. J Clin Immunol 2010; 30:777-89. [PMID: 20886282 PMCID: PMC2970823 DOI: 10.1007/s10875-010-9468-4] [Citation(s) in RCA: 175] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 09/14/2010] [Indexed: 11/30/2022]
Abstract
The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn.
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Affiliation(s)
- Timothy T Kuo
- Division of Gastroenterology, Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA.
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13
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Baker K, Qiao SW, Kuo T, Kobayashi K, Yoshida M, Lencer WI, Blumberg RS. Immune and non-immune functions of the (not so) neonatal Fc receptor, FcRn. Semin Immunopathol 2009; 31:223-36. [PMID: 19495758 PMCID: PMC3898171 DOI: 10.1007/s00281-009-0160-9] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 05/14/2009] [Indexed: 02/06/2023]
Abstract
Careful regulation of the body's immunoglobulin-G (IgG) and albumin concentrations is necessitated by the importance of their respective functions. As such, the neonatal Fc receptor (FcRn) which, as a single receptor, is capable of regulating both of these molecules, has become an important focus of investigation. In addition to these essential protection functions, FcRn possesses a host of other functions that are equally as critical. During the very first stages of life, FcRn mediates the passive transfer of IgG from mother to offspring both before and after birth. In the adult, FcRn regulates the persistence of both IgG and albumin in the serum as well as the movement of IgG, and any bound cargo, between different compartments of the body. This shuttling allows for the movement not only of monomeric ligand but also of antigen/antibody complexes from one cell type to another in such a way as to facilitate the efficient initiation of immune responses towards opsonized pathogens. As such, FcRn continues to play the role of an immunological sensor throughout adult life, particularly in regions such as the gut which are exposed to a large number of infectious antigens. Increasing appreciation for the contributions of FcRn to both homeostatic and pathological states is generating an intense interest in the potential for therapeutic modulation of FcRn binding. A greater understanding of FcRn's pleiotropic roles is thus imperative for a variety of therapeutic purposes.
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Affiliation(s)
- Kristi Baker
- Division of Gastroenterology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Shuo-Wang Qiao
- Rikshospitalet University Hospital, 0027 Oslo, Norway, University of Oslo, 0027 Oslo, Norway
| | - Timothy Kuo
- Division of Gastroenterology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Kanna Kobayashi
- Division of Gastroenterology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Masaru Yoshida
- Department of Gastroenterology & The Integrated Center for Mass Spectrometry, Kobe University Graduate School of Medecine, Hyogo, Japan
| | - Wayne I. Lencer
- Harvard Digestive Diseases Center, Boston, MA 02115, USA, GI Cell Biology, Division of Pediatric Gastroenterology and Nutrition, Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA, Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Richard S. Blumberg
- Division of Gastroenterology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA, Harvard Digestive Diseases Center, Boston, MA 02115, USA
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14
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Ward ES, Ober RJ. Chapter 4: Multitasking by exploitation of intracellular transport functions the many faces of FcRn. Adv Immunol 2009; 103:77-115. [PMID: 19755184 DOI: 10.1016/s0065-2776(09)03004-1] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The MHC Class I-related receptor, FcRn, transports antibodies of the immunoglobulin G (IgG) class within and across a diverse array of different cell types. Through this transport, FcRn serves multiple roles throughout adult life that extend well beyond its earlier defined function of transcytosing IgGs from mother to offspring. These roles include the maintenance of IgG levels and the delivery of antigen in the form of immune complexes to degradative compartments within cells. Recent studies have led to significant advances in knowledge of the intracellular trafficking of FcRn and (engineered) IgGs at both the molecular and cellular levels. The engineering of FcRn-IgG (or Fc) interactions to generate antibodies of increased longevity represents an area of active interest, particularly in the light of the expanding use of antibodies in therapy. The strict pH dependence of FcRn-IgG interactions, with binding at pH 6 that becomes essentially undetectable as near neutral pH is approached, is essential for efficient transport. The requirement for retention of low affinity at near neutral pH increases the complexity of engineering antibodies for increased half-life. Conversely, engineered IgGs that have gained significant binding for FcRn at this pH can be potent inhibitors of FcRn that lower endogenous IgG levels and have multiple potential uses as therapeutics. In addition, molecular studies of FcRn-IgG interactions indicate that mice have limitations as preclinical models for FcRn function, primarily due to cross-species differences in FcRn-binding specificity.
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Affiliation(s)
- E Sally Ward
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Liu X, Ye L, Christianson GJ, Yang JQ, Roopenian DC, Zhu X. NF-kappaB signaling regulates functional expression of the MHC class I-related neonatal Fc receptor for IgG via intronic binding sequences. THE JOURNAL OF IMMUNOLOGY 2007; 179:2999-3011. [PMID: 17709515 PMCID: PMC2667116 DOI: 10.4049/jimmunol.179.5.2999] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The neonatal Fc receptor for IgG (FcRn) functions to transport maternal IgG to a fetus or newborn and to protect IgG from degradation. Although FcRn is expressed in a variety of tissues and cell types, the extent to which FcRn expression is regulated by immunological and inflammatory events remains unknown. Stimulation of intestinal epithelial cell lines, macrophage-like THP-1, and freshly isolated human monocytes with the cytokine TNF-alpha rapidly up-regulated FcRn gene expression. In addition, the TLR ligands LPS and CpG oligodeoxynucleotide enhanced the level of FcRn expression in THP-1 and monocytes. Treatment of TNF-stimulated THP-1 cells with the NF-kappaB-specific inhibitor or overexpression of a dominant negative mutant inhibitory NF-kappaB (IkappaBalpha; S32A/S36A) resulted in down-regulation of FcRn expression. By using chromatin immunoprecipitation we identified three NF-kappaB binding sequences within introns 2 and 4 of the human FcRn gene. An EMSA confirmed the p50/p50 and/or p65/p50 complex (s) bound to intron 2- or 4-derived oligonucleotides containing putative NF-kappaB binding sequences, respectively. The intronic NF-kappaB sequences in combination with the promoter or alone regulated the expression of a luciferase reporter gene in response to TNF-alpha stimulation or overexpression of NF-kappaB p65 and p50. DNA looping interactions potentially occurred after the stimulation between intronic NF-kappaB sequences and the FcRn promoter as shown by a chromosome conformation capture assay. Finally, TNF-alpha stimulations enhanced IgG transport across an intestinal Caco-2 epithelial monolayer. Together, these data provide the first evidence that NF-kappaB signaling via intronic sequences regulates FcRn expression and function.
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Affiliation(s)
- Xindong Liu
- Laboratory of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | - Lilin Ye
- Laboratory of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
| | | | - Jun-Qi Yang
- Department of Genome Science, University of Cincinnati College of Medicine, Cincinnati, OH 45237
| | | | - Xiaoping Zhu
- Laboratory of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742
- Address correspondence and reprint requests to Dr. Xiaoping Zhu, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, 8075 Greenmead Drive, College Park, MD 20742. E-mail address:
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Guo G, Bauer S, Hecht J, Schulz MH, Busche A, Robinson PN. A short ultraconserved sequence drives transcription from an alternate FBN1 promoter. Int J Biochem Cell Biol 2007; 40:638-50. [PMID: 17996480 DOI: 10.1016/j.biocel.2007.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 09/25/2007] [Accepted: 09/25/2007] [Indexed: 11/16/2022]
Abstract
FBN1, the gene mutated in Marfan syndrome, encodes fibrillin-1, a large glycoprotein component of the extracellular microfibrils. Human FBN1 has three untranslated upstream exons, and homologous sequences can be identified in a number of mammalian species. In this work, we have used functional assays to characterize the FBN1 upstream region. Sequences upstream of exon 1 and at least two of the upstream untranslated exons were shown to possess promoter activity in vitro. The strongest activity in luciferase assays was shown for sequences upstream of the untranslated exon A. Sequence analysis of the sequences in and upstream of exon A in humans and six other mammalian species demonstrated several highly conserved potential cis-acting sequences as well as a 66-basepair (bp) ultraconserved sequence with nearly perfect conservation in the seven species. The ultraconserved sequence contains an initiator element (Inr), a downstream promoter element (DPE), and a 10-bp palindromic element. Mutational assays showed that both the Inr and the DPE are critical for full promoter activity. A mutation of the 10-bp palindromic element completely abolished basal promoter activity. The element was shown to bind specifically to an unknown nuclear protein by electrophoretic mobility shift assay. Ultraconservation within an alternate promoter has not been previously reported. We suggest that the ultraconservation may reflect the importance of finely tuned regulation of alternate transcription of FBN1 and that the sequences involved have been under negative selective pressure for at least the last 180 million years of mammalian evolution.
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Affiliation(s)
- Gao Guo
- Institute for Medical Genetics, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
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Abstract
The neonatal Fc receptor for IgG (FcRn) has been well characterized in the transfer of passive humoral immunity from a mother to her fetus. In addition, throughout life, FcRn protects IgG from degradation, thereby explaining the long half-life of this class of antibody in the serum. In recent years, it has become clear that FcRn is expressed in various sites in adults, where its potential function is now beginning to emerge. In addition, recent studies have examined the interaction between FcRn and the Fc portion of IgG with the aim of either improving the serum half-life of therapeutic monoclonal antibodies or reducing the half-life of pathogenic antibodies. This Review summarizes these two areas of FcRn biology.
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Affiliation(s)
- Derry C Roopenian
- The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA.
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Qiao SW, Lencer WI, Blumberg RS. How the controller is controlled - neonatal Fc receptor expression and immunoglobulin G homeostasis. Immunology 2006; 120:145-7. [PMID: 17140402 PMCID: PMC2265855 DOI: 10.1111/j.1365-2567.2006.02507.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Shuo-Wang Qiao
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Doleschall M, Zhao Y, Mayer B, Hammarström L, Kacskovics I. Isolation of the gene encoding the bovine neonatal Fc receptor. Vet Immunol Immunopathol 2005; 108:145-50. [PMID: 16095719 DOI: 10.1016/j.vetimm.2005.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The role of an IgG-Fc receptor (FcRn) that resembles a class I MHC Ag in transporting IgGs through epithelial cells was recently shown in selected species. Here we report our preliminary characterization of a clone encoding the alpha chain of the bovine FcRn from a BAC library. The recombinant BAC DNA was digested, analyzed by Southern blot hybridization and a bovine FcRn positive 9 kb long fragment was subcloned and partially sequenced. The exon/intron organization of the bovine FcRn alpha chain gene was deduced by comparison with its cDNA sequence. The sequence revealed a similar organization to the human and mouse FcRn alpha chain genes. The bovine FcRn alpha chain gene has acquired several repetitive sequences in its 5'-flanking region, including multiple SINE and LINE elements. Potential binding sites for transcription factors within the 5'-flanking sequence were identified using TESS and TFSEARCH programs. The 5'-flanking region of the bFcRn alpha chain gene was analyzed for its ability to directly express the luciferase reporter gene in bovine mammary gland epithelial cells. Transient transfection of a luciferase construct revealed that there was promoter activity in the region -1787 to +92 of the 5'-flanking sequence.
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Affiliation(s)
- Márton Doleschall
- Department of Physiology and Biochemistry, Faculty of Veterinary Science, Szent Istvan University, P.O. Box 2, H-1400 Budapest, Hungary
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