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Román-Carrasco P, Hemmer W, Cabezas-Cruz A, Hodžić A, de la Fuente J, Swoboda I. The α-Gal Syndrome and Potential Mechanisms. FRONTIERS IN ALLERGY 2021; 2:783279. [PMID: 35386980 PMCID: PMC8974695 DOI: 10.3389/falgy.2021.783279] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
The α-Gal syndrome is a complex allergic disease characterized by the development of specific IgE antibodies against the carbohydrate galactose-α-1,3-galactose (α-Gal), an oligosaccharide present in cells and tissues of non-primate mammals. Individuals with IgE antibodies to α-Gal suffer from a delayed form of anaphylaxis following red meat consumption. There are several features that make the α-Gal syndrome such a unique allergic disease and distinguish it from other food allergies: (1) symptoms causing IgE antibodies are directed against a carbohydrate moiety, (2) the unusual delay between the consumption of the food and the onset of the symptoms, and (3) the fact that primary sensitization to α-Gal occurs via tick bites. This review takes a closer look at the immune response against α-Gal, in healthy and in α-Gal allergic individuals. Furthermore, the similarities and differences between immune response against α-Gal and against the other important glycan moieties associated with allergies, namely cross-reactive carbohydrate determinants (CCDs), are discussed. Then different mechanisms are discussed that could contribute to the delayed onset of symptoms after consumption of mammalian meat. Moreover, our current knowledge on the role of tick bites in the sensitization process is summarized. The tick saliva has been shown to contain proteins carrying α-Gal, but also bioactive molecules, such as prostaglandin E2, which is capable of stimulating an increased expression of anti-inflammatory cytokines while promoting a decrease in the production of proinflammatory mediators. Together these components might promote Th2-related immunity and trigger a class switch to IgE antibodies directed against the oligosaccharide α-Gal. The review also points to open research questions that remain to be answered and proposes future research directions, which will help to get a better understanding and lead to a better management of the disease.
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Affiliation(s)
- Patricia Román-Carrasco
- Molecular Biotechnology Section, FH Campus Wien, University of Applied Sciences, Vienna, Austria
| | | | - Alejandro Cabezas-Cruz
- Anses, INRAE, Ecole Nationale Vétérinaire d'Alfort, UMR BIPAR, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Adnan Hodžić
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - José de la Fuente
- SaBio, Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, United States
| | - Ines Swoboda
- Molecular Biotechnology Section, FH Campus Wien, University of Applied Sciences, Vienna, Austria
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Carbohydrate antigen microarray analysis of serum IgG and IgM antibodies before and after adult porcine islet xenotransplantation in cynomolgus macaques. PLoS One 2021; 16:e0253029. [PMID: 34138941 PMCID: PMC8211184 DOI: 10.1371/journal.pone.0253029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/25/2021] [Indexed: 11/19/2022] Open
Abstract
Understanding the anti-carbohydrate antibody response toward epitopes expressed on porcine cells, tissues, and organs is critical to advancing xenotransplantation toward clinical application. In this study, we determined IgM and IgG antibody specificities and relative concentrations in five cynomolgus monkeys at baseline and at intervals following intraportal xenotransplantation of adult porcine islets. This study utilized a carbohydrate antigen microarray that comprised more than 400 glycoconjugates, including historically reported α-Gal and non-α-Gal carbohydrate antigens with various modifications. The elicited anti-carbohydrate antibody responses were predominantly IgM compared to IgG in 4 out of 5 monkeys. Patterns of elicited antibody responses greater than 1.5 difference (log2 base units; 2.8-fold on a linear scale) from pre-serum to post-serum sampling specific for carbohydrate antigens were heterogeneous and recipient-specific. Increases in the elicited antibody response to α-Gal, Sda, GM2 antigens, or Lexis X antigen were found in individual monkeys. The novel carbohydrate structures Galβ1-4GlcNAcβ1-3Galβ1 and N-linked glycans with Manα1-6(GlcNAcβ1-2Manα1-3)Manβ1-4GlcNAcβ structure were common targets of elicited IgM antibodies. These results provide important insights into the carbohydrate epitopes that elicit antibodies following pig-to-monkey islet xenotransplantation and reveal possible targets for gene editing.
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Breimer ME, Holgersson J. The Structural Complexity and Animal Tissue Distribution of N-Glycolylneuraminic Acid (Neu5Gc)-Terminated Glycans. Implications for Their Immunogenicity in Clinical Xenografting. Front Mol Biosci 2019; 6:57. [PMID: 31428616 PMCID: PMC6690001 DOI: 10.3389/fmolb.2019.00057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/04/2019] [Indexed: 12/13/2022] Open
Abstract
N-Glycolylneuraminic acid (Neu5Gc)-terminated glycans are present in all animal cells/tissues that are already used in the clinic such as bioprosthetic heart valves (BHV) as well as in those that potentially will be xenografted in the future to overcome end stage cell/organ failure. Humans, as a species lack this antigen determinant and can react with an immune response after exposure to Neu5Gc present in these products/cells/tissues. Genetically engineered source animals lacking Neu5Gc has been generated and so has animals that in addition lack the major αGal xenoantigen. The use of cells/tissues/organs from such animals may improve the long-term performance of BHV and allow future xenografting. This review summarizes the present knowledge regarding structural complexity and tissue distribution of Neu5Gc on glycans of cells/tissue/organs already used in the clinic or intended for treatment of end stage organ failure by xenografting. In addition, we briefly discuss the role of anti-Neu5Gc antibodies in the xenorejection process and how knowledge about Neu5Gc structural complexity can be used to design novel diagnostics for anti-Neu5Gc antibody detection.
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Affiliation(s)
- Michael E Breimer
- Department of Surgery, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jan Holgersson
- Laboratory Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Holodick NE, Rodríguez-Zhurbenko N, Hernández AM. Defining Natural Antibodies. Front Immunol 2017; 8:872. [PMID: 28798747 PMCID: PMC5526850 DOI: 10.3389/fimmu.2017.00872] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/10/2017] [Indexed: 01/05/2023] Open
Abstract
The traditional definition of natural antibodies (NAbs) states that these antibodies are present prior to the body encountering cognate antigen, providing a first line of defense against infection thereby, allowing time for a specific antibody response to be mounted. The literature has a seemingly common definition of NAbs; however, as our knowledge of antibodies and B cells is refined, re-evaluation of the common definition of Nabs may be required. Defining Nabs becomes important as the function of NAb production is used to define B cell subsets (1) and as these important molecules are shown to play numerous roles in the immune system (Figure 1). Herein, we aim to briefly summarize our current knowledge of NAbs in the context of initiating a discussion within the field of how such an important and multifaceted group of molecules should be defined.
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Affiliation(s)
- Nichol E Holodick
- Department of Biomedical Sciences, Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI, United States
| | - Nely Rodríguez-Zhurbenko
- Natural Antibodies Group, Tumor Immunology Division, Center of Molecular Immunology, Havana, Cuba
| | - Ana María Hernández
- Natural Antibodies Group, Tumor Immunology Division, Center of Molecular Immunology, Havana, Cuba
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Holgersson J, Rydberg L, Breimer ME. Molecular deciphering of the ABO system as a basis for novel diagnostics and therapeutics in ABO incompatible transplantation. Int Rev Immunol 2013; 33:174-94. [PMID: 24350817 DOI: 10.3109/08830185.2013.857408] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In recent years ABO incompatible kidney transplantation (KTx) has become a more or less clinical routine procedure with graft and patient survival similar to those of ABO compatible transplants. Antigen-specific immunoadsorption (IA) for anti-A and anti-B antibody removal constitutes in many centers an important part of the treatment protocol. ABO antibody titration by hemagglutination is guiding the treatment; both if the recipient can be transplanted as well as in cases of suspected rejections if antibody removal should be performed. Despite the overall success of ABO incompatible KTx, there is still room for improvements and an extension of the technology to include other solid organs. Based on an increased understanding of the structural complexity and tissue distribution of ABH antigens and the fine epitope specificity of the ABO antibody repertoire, improved IA matrices and ABO antibody diagnostics should be developed. Furthermore, understanding the molecular mechanisms behind accommodation of ABO incompatible renal allografts could make it possible to induce long-term allograft acceptance also in human leukocyte antigen (HLA) sensitized recipients and, perhaps, also make clinical xenotransplantation possible.
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Affiliation(s)
- Jan Holgersson
- 1Department of Clinical Chemistry and Transfusion Medicine and
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Byrne GW, McGregor CGA. First quantification of alpha-Gal epitope in current glutaraldehyde-fixed heart valve bioprosthesis (by Naso et al.). Xenotransplantation 2013; 21:11-2. [PMID: 24188452 DOI: 10.1111/xen.12072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic, Rochester, MN, USA.
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Shilova N, Huflejt ME, Vuskovic M, Obukhova P, Navakouski M, Khasbiullina N, Pazynina G, Galanina O, Bazhenov A, Bovin N. Natural Antibodies Against Sialoglycans. Top Curr Chem (Cham) 2013; 366:169-81. [PMID: 24037491 DOI: 10.1007/128_2013_469] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Natural antibodies, part of the innate immunity system, are produced at strictly regulated levels in normal sera without immunization and thus are part of the innate immune system. The best studied natural antibodies are those directed against blood group antigens A and B and xeno-antigens including glycolylneuraminic acid containing Hanganutziu-Deicher (HD) glycolipid. Abnormal levels of anti-glycan antibodies were found in a number of pathologies. In many cases pathological antibodies are known to bind gangliosides. The genesis of anti-glycan antibodies in healthy humans and the reasons for their changes in pathologies are poorly understood. With a growing interest in their diagnostic applications, it is important to determine the carbohydrate structures that are recognized by antibodies present in the circulation of healthy individuals. We tested a large number of healthy donors using a printed glycan array (PGA) in a microchip format. The PGA contained ~300 glycans, representing mostly normal mammalian structures of glycoproteins and glycolipids, and many of the structures presented are biologically relevant sialylated motifs. As revealed by PGA, the sera interacted with at least 70 normal human glycans. With only few exceptions, antibodies recognizing sialosides have not been identified. Moderate levels of antibodies and moderate variability were observed in the case of SiaT n and its glycolyl variant. Unexpectedly, we found minimal antibody titer directed against Neu5Gcα and the trisaccharide Neu5Gcα2-6Galβ1-4GlcNAc, although this form of neuraminic acid does not occur naturally in humans. Antibodies recognizing sialosides in unnatural β-configuration have been detected and confirmed Springer's paradigm that circulating antibodies represent a reaction against bacteria. Gram-negative bacteria contain LPS with βKDN and/or βKDO which are very close analogs of Neu5Ac that are found in β-connected form. Antibodies against the biantennary N-glycan chain, (Neu5Acα2-6Galβ1-4GlcNAcβ1-2Manα)2-3,6-Manβ1-4GlcNAcβ1-4GlcNAc were never observed and similarly we never saw antibodies directed against the SiaLe(a)/SiaLe (x) motifs. Anti-sialoglycan antibodies can be masked with gangliosides: for example, we observe about a five times higher level of anti-GD3 in purified total IgG compared to the same concentration of total Ig in the composition of native serum. For several antibodies we observed anomalous binding in diluted sera, namely, the signals towards sialylated glycans were increased in the PGA if diluted sera were used.
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Affiliation(s)
- Nadezhda Shilova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
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Repertoire of human natural anti-glycan immunoglobulins. Do we have auto-antibodies? Biochim Biophys Acta Gen Subj 2012; 1820:1373-82. [PMID: 22365885 DOI: 10.1016/j.bbagen.2012.02.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 02/07/2012] [Accepted: 02/09/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND Profiling of donor's antibodies using glycan arrays demonstrated presence of antibodies capable of binding to >100 mammalian glycans or their fragments. For example, relatively high binding to Galα1-4Galβ1-4GlcNAc (P(1)), Galα1-4Galβ1-4Glc (P(k)), Galβ1-3GlcNAc (Le(c)), 4-O-SuGalβ1-4GlcNAc, and GalNAcα1-3GalNAc (Fs) was found in all tested individuals. Affinity isolation using hapten-specific chromatography in combination with epitope mapping revealed their glycotopes. Notably, a significant part of the antibodies was capable of recognizing a fragment of larger glycans, for example, -Galβ1-4Glc of glycolipids, or Fucα1-3GlcNAc motif of Le(X)/Le(Y) antigens. Their epitope specificity did not vary between different healthy individuals. Nominally, all the mentioned immunoglobulins could be classified as auto-antibodies. METHODS In this work we re-evaluated results published earlier and analyzed new data to address the question why autologous antibodies found in healthy individuals do not cause severe auto-immune reactions. RESULTS In all cases the presumably "auto" antibodies were found to bind short fragments "subtracted" from larger glycans whereas recognition of the same fragment in the context of the whole natural chain was completely abolished. Thus, in spite of numerous formally positive signals observed on the printed glycan array, we are yet unable to identify in blood serum of healthy individuals true auto-antibodies capable of binding carbohydrate chains in their naturally occurring form. GENERAL SIGNIFICANCE The identified natural anti-glycan antibodies were found to be specific, high-titer and population conservative immunoglobulins - all of this suggesting as yet unknown biological role(s) of the studied proteins. This article is part of a Special Issue entitled Glycoproteomics.
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Diversity of natural anti-α-galactosyl antibodies in human serum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 705:571-83. [PMID: 21618130 DOI: 10.1007/978-1-4419-7877-6_30] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Bernth-Jensen JM, Møller BK, Jensenius JC, Thiel S. Biological variation of anti-αGal-antibodies studied by a novel Time-Resolved ImmunoFluorometric Assay. J Immunol Methods 2011; 373:26-35. [DOI: 10.1016/j.jim.2011.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 07/04/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
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Diswall M, Gustafsson A, Holgersson J, Sandrin MS, Breimer ME. Antigen-binding specificity of anti-αGal reagents determined by solid-phase glycolipid-binding assays. A complete lack of αGal glycolipid reactivity in α1,3GalT-KO pig small intestine. Xenotransplantation 2011; 18:28-39. [PMID: 21342285 DOI: 10.1111/j.1399-3089.2011.00623.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND αGal-specific lectins, monoclonal and polyclonal antibodies (Abs) are widely used in xenotransplantation research. Immunological assays such as immunohistochemistry, flow cytometry, Western blot and thin layer chromatography are often the only applicable characterization procedures when limited amount of tissue is available and biochemical characterization is impossible. Hence, detailed knowledge of the Ab/lectin carbohydrate-binding specificity is essential. METHODS The binding specificity of human blood group AB serum, three different affinity-purified human polyclonal anti-Gal Ab batches, and two anti-Gal mAb clones (TH5 and 15.101) as well as Griffonia simplicifolia isolectin B4 and Marasmius oreades agglutinin were examined for reactivity with glycolipid fractions isolated from human and pig (wild-type and α1,3GalT-KO) tissues using thin layer chromatogram and microtiter well binding assays. RESULTS All anti-Gal-specific reagents reacted with the pentaglycosylceramide Galα1,3nLc4, and several 6-12 sugar compounds in wild-type pig kidneys. However, their staining intensity with different αGal antigens varied considerably. Some, but not all, anti-Gal reagents cross-reacted with a pure iGb3 glycolipid reference compound. No reactivity with glycolipids isolated from α1,3GalT-KO pig small intestine or human tissues was found, confirming the specificity of the anti-Gal reagents in those tissues for α1,3Gal-epitopes produced by the α1,3GalT (GGTA1). CONCLUSIONS Different anti-Gal reagents vary in their carbohydrate epitope specificity. Mono-/polyclonal Abs and lectins have different carbohydrate epitope fine specificity toward pig glycolipids as well as purified Galα1,3nLc4, and iGb3. Despite the difference in αGal specificity, all reagents were completely non-reactive with glycolipids isolated from α1,3GalT-KO pig small intestine.
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Affiliation(s)
- Mette Diswall
- Department of Surgery, Sahlgrenska Academy at Gothenburg University, Sahlgrenska University Hospital, Gothenburg, Sweden.
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Huflejt ME, Vuskovic M, Vasiliu D, Xu H, Obukhova P, Shilova N, Tuzikov A, Galanina O, Arun B, Lu K, Bovin N. Anti-carbohydrate antibodies of normal sera: findings, surprises and challenges. Mol Immunol 2009; 46:3037-49. [PMID: 19608278 DOI: 10.1016/j.molimm.2009.06.010] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 06/10/2009] [Indexed: 01/01/2023]
Abstract
We have used microchip format glycan array to characterize the individual carbohydrate recognition patterns by antibodies (Ab) in sera of 106 healthy donors. The glycan library included blood group antigens and other most frequent terminal oligosaccharides and their cores of mammalian N- and O-linked glycoproteins and glycolipids, tumor-associated carbohydrate antigens, and common components of bacterial/pathogenic polysaccharides and lipopolysaccharides, totally 205 glycans. The serum Ab interacted with at least 50 normal human glyco-motifs. Apart from expected blood group-, xeno- (heterophil) and infection-related binding activities, we observed a number of new and unexpected features. The surprising, relatively high antibody binding was found to the blood group P(1) and P(k) trisaccharides and H(type 2) trisaccharide. Novel and very high binding activities have been observed towards Galbeta1-3GlcNAc (Le(C)) related glycans, especially 3'-O-Su-Le(C), and towards 4'-O-sulfated lactosamine. Relatively high and uniform Ab binding to GalNAcalpha1-3Gal disaccharide demonstrated absence of correlation with fucosylated blood group A GalNAcalpha1-3(Fucalpha1-2)Gal antigen-similarly to well known relationship between Galalpha1-3Gal and true, fucosylated blood group B Galalpha1-3(Fucalpha1-2)Gal antigen. The binding intensity to Galalpha1-3Galbeta1-4GlcNAc xenoantigen was shown to be rather modest. Absence or very low Ab binding was found against oligosialic acid, sialooligosaccharides except SiaT(n), type 2 backbone glycans such as Le(y), and biantennary N-chain as well as its truncated forms, i.e. without terminal Sia, SiaGal, and SiaGalGlcNAc motifs. We have also found that Ab are capable of recognizing the short inner core typical for glycolipids (-Galbeta1-4Glc) and glycoproteins (-GalNAcalpha) as a fragment of bigger glycans.
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Affiliation(s)
- Margaret E Huflejt
- New York University School of Medicine, Dept. of Cardiothoracic Surgery, New York, NY 10016, USA
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Blixt O, Kumagai-Braesch M, Tibell A, Groth CG, Holgersson J. Anticarbohydrate Antibody Repertoires in Patients Transplanted with Fetal Pig Islets Revealed by Glycan Arrays. Am J Transplant 2009. [DOI: 10.1111/j.1600-6143.2008.02471.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Obukhova P, Rieben R, Bovin N. Normal human serum contains high levels of anti-Gal alpha 1-4GlcNAc antibodies. Xenotransplantation 2008; 14:627-35. [PMID: 17991151 DOI: 10.1111/j.1399-3089.2007.00436.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Natural xenoreactive antibodies (Abs) directed against the Bdi-epitope (Gal alpha 1-3Gal beta) on the cells of non-primate mammals take part in hyperacute rejection of xenotransplanted organs. We found that some Abs, which were one-step affinity purified on Bdi-Sepharose, cross-reacted with the disaccharide Gal alpha 1-4GlcNAc beta. The epitope Gal alpha 1-4GlcNAc has not been identified on mammals or bacterial polysaccharides yet. METHODS To isolate the antibodies of the corresponding specificity the disaccharide was immobilized on Sepharose and antibodies were affinity purified from pooled serum of blood group O individuals. RESULTS These one-step purified Abs cross-reacted with Bdi, but after a prior absorption step on Bdi-Sepharose no cross-reactivity with Bdi was observed any longer. Surprisingly, the quantity of anti-Gal alpha 1-4GlcNAc isolated from the same serum pool, 4-7 microg/ml, was equal to that of anti-Bdi or more. Independently of ABO blood groups all the tested healthy donors had anti-Gal alpha 1-4GlcNAc Abs at a similar level. Monospecific anti-Gal alpha 1-4GlcNAc Abs were not cytotoxic towards porcine cells. CONCLUSIONS 1. The actual concentration of monospecific, xenoreactive Gal alpha 1-3Gal beta Abs in blood may be considerably lower than the value referred to in the literature for 'anti-alpha Gal' or 'anti-Galili' antibodies. 2. Anti-Gal alpha 1-4GlcNAc Abs seem not to be important for xenotransplantation.
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Affiliation(s)
- Polina Obukhova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russian Federation
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Milland J, Yuriev E, Xing PX, McKenzie IFC, Ramsland PA, Sandrin MS. Carbohydrate residues downstream of the terminal Galalpha(1,3)Gal epitope modulate the specificity of xenoreactive antibodies. Immunol Cell Biol 2007; 85:623-32. [PMID: 17724458 DOI: 10.1038/sj.icb.7100111] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Carbohydrates are involved in many immunological responses including the rejection of incompatible blood, tissues and organs. Carbohydrate antigens with Galalpha(1,3)Gal epitopes are recognized by natural antibodies in humans and pose a major barrier for pig-to-human xenotransplantation. Genetically modified pigs have been established that have no functional alpha1,3-galactosyltransferase (alpha1,3GT), which transfers alphaGal to N-acetyllactosamine (LacNAc) type oligosaccharides. However, a low level of Galalpha(1,3)Gal is still expressed in alpha1,3GT knockout animals in the form of a lipid, isoglobotrihexosylceramide (iGb3), which is produced by iGb3 synthase on lactose (Lac) type core structures. Here, we define the reactivity of a series of monoclonal antibodies (mAb) generated in alpha1,3GT-/- mice immunized with rabbit red blood cells (RbRBC), as a rich source of lipid-linked antigens. Interestingly, one mAb (15.101) binds weakly to synthetic and cell surface-expressed Galalpha(1,3)Gal on LacNAc, but strongly to versions of the antigen on Lac cores, including iGb3. Three-dimensional models suggest that the terminal alpha-linked Gal binds tightly into the antibody-binding cavity. Furthermore, antibody interactions were predicted with the second and third monosaccharide units. Collectively, our findings suggest that although the terminal carbohydrate residues confer most of the binding affinity, the fine specificity is determined by subsequent residues in the oligosaccharide.
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Affiliation(s)
- Julie Milland
- Department of Surgery (Austin Health), University of Melbourne, Heidelberg, Victoria, Australia
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Wiebe K, Oezkur M, Pöling J, Haverich A. Potential of an Injectable Polymer to Prevent Hyperacute Rejection of Ex Vivo Perfused Porcine Lungs. Transplantation 2006; 82:681-8. [PMID: 16969293 DOI: 10.1097/01.tp.0000234819.18069.53] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Removal of xenoreactive antibodies in pig-to-human lung transplantation by columns or organ perfusions proofed to be unsatisfactory and associated with adverse effects. In an ex-vivo lung perfusion model, we evaluated the potential of a soluble trisaccharide polymer (GAS914) to bind alpha-Gal antibodies and to protect a pulmonary xenograft from hyperacute rejection (HAR) and pulmonary xenograft dysfunction. METHODS Porcine lungs were perfused with fresh human blood for 240 min. In the GAS914 treated group (n=6) the polymer was applied in three different concentrations. The control group (n=6) received no GAS914. Survival and function of perfused xenografts were monitored, and alpha-Gal antibodies as well as cytolytic anti-porcine antibodies analyzed. RESULTS In the GAS-treated group survival of lungs was significantly prolonged, pulmonary vascular resistance reduced, pulmonary edema prevented, and oxygenation improved. On histopathological evaluation application of GAS resulted in minimal graft injury and significantly less deposition of the terminal complement complex C5b-9. Following application of GAS914, up to 89.8% of IgG alpha-Gal, 79.5% of IgM and 73.6% of anti-porcine antibodies in the human blood were bound by the polymer. Subsequent perfusion of porcine lungs resulted in absorption of only 3% of the baseline IgG alpha-Gal antibodies in the GAS914 group, compared to 87% in the controls. CONCLUSIONS In this ex-vivo lung perfusion model, a trisaccharide polymer prevented immediate HAR, due to effective removal of alpha-Gal antibodies. In combination with additional strategies GAS914 may be a valuable tool in overcoming HAR and dysfunction of pulmonary xenografts.
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Affiliation(s)
- Karsten Wiebe
- Division of Thoracic and Cardiovascular Surgery, Hannover Medical School, Hannover, Germany.
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Wang J, Zhang B, Fang J, Sujino K, Li H, Otter A, Hindsgaul O, Palcic MM, Wang PG. Frontal Affinity Chromatography Coupled to Mass Spectrometry: An Effective Method for KdDetermination and Screening of α‐Gal Derivatives Binding to Anti‐Gal Antibodies (IgG). J Carbohydr Chem 2006. [DOI: 10.1081/car-120025323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jianqiang Wang
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
- b Department of Chemistry , Wayne State University , Detroit, Michigan, 48202, USA
- c Triad Therapeutics, Inc. , 9381 Judicial Drive, San Diego, California, 92121, USA
| | - Boyan Zhang
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Jianwen Fang
- b Department of Chemistry , Wayne State University , Detroit, Michigan, 48202, USA
| | - Keiko Sujino
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Hong Li
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Albin Otter
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Ole Hindsgaul
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Monica M. Palcic
- a Department of Chemistry , University of Alberta , Edmonton, Alberta, T6G 2G2, Canada
| | - Peng George Wang
- b Department of Chemistry , Wayne State University , Detroit, Michigan, 48202, USA
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18
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Holgersson J, Gustafsson A, Breimer ME. Characteristics of protein-carbohydrate interactions as a basis for developing novel carbohydrate-based antirejection therapies. Immunol Cell Biol 2005; 83:694-708. [PMID: 16266322 DOI: 10.1111/j.1440-1711.2005.01373.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The relative shortage of human organs for transplantation is today the major barrier to a broader use of transplantation as a means of treating patients with end-stage organ failure. This barrier could be partly overcome by an increased use of blood group ABO-incompatible live donors, and such trials are currently underway at several transplant centres. If xenotransplantation can be used clinically in the future, the human organ shortage will, in principle, be eradicated. In both these cases, carbohydrate antigens and the corresponding anti-carbohydrate antibodies are the major primary immunological barriers to overcome. Refined carbohydrate-based therapeutics may permit an increased number of ABO-incompatible transplantations to be carried out, and may remove the initial barriers to clinical xenotransplantation. Here, we will discuss the chemical characteristics of protein-carbohydrate interactions and outline carbohydrate-based antirejection therapies as used today in experimental as well as in clinical settings. Novel mucin-based adsorbers of natural anti-carbohydrate antibodies will also be described.
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Affiliation(s)
- Jan Holgersson
- Division of Clinical Immunology, Karolinska Institute, Karolinska University Hospital at Huddinge, Stockholm, Sweden
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19
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Smorodin EP, Kurtenkov OA, Shevchuk IN, Tanner RH. The isolation and characterization of human natural alphaGal-specific IgG antibodies applicable to the detection of alphaGal-glycosphingolipids. J Immunoassay Immunochem 2005; 26:145-56. [PMID: 15794123 DOI: 10.1081/ias-200051999] [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: 01/11/2023]
Abstract
The Galalpha1-3Galbeta (alphaGal) hapten is xenogeneic for humans; natural anti-alphaGal antibodies are present in human serum. To study the possible abnormal expression of the alphaGal in humans and the pathophysiological role of antibodies, the method of affinity purification of human anti-alphaGal IgG was developed. The specificity of antibodies was evaluated using polyacrylamide (PAA)-based glycoconjugates in direct and competitive enzyme-linked immunosorbent assays (ELISA). The purified antibodies exhibited alphaGal-restricted specificity. The IC50 value for alphaGal-PAA was equal to 4 x 10(-8) M. In a competitive assay, the Galalpha1-3(Fucalpha1-2)Galbeta-PAA (trisaccharide of blood group B) was found to be one hundred times less active inhibitor than alphaGal-PAA. The multivalent alphaGal-PAA was 1100 times more potent an inhibitor than the monovalent spacered alphaGal-saccharide. The antibodies did not show any reactivity to the negatively charged antigens (DNA, human tumor-derived mucins). At a concentration of 2 microg/mL, the antibodies agglutinated rabbit erythrocytes but not hare erythrocytes. The high reactivity of antibodies to the alphaGal-glycosphingolipids of rabbit erythrocytes and the pig kidney was shown by a modified sensitive method of thin-layer chromatography with immunodetection.
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Affiliation(s)
- E P Smorodin
- Department of Oncology & Immunology, National Institute for Health Development, Hiiu 42, 11619, Tallinn, Estonia.
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20
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Moscoso I, Hermida-Prieto M, Mañez R, Lopez-Pelaez E, Centeno A, Diaz TM, Domenech N. Lack of Cross-Species Transmission of Porcine Endogenous Retrovirus in Pig-to-Baboon Xenotransplantation with Sustained Depletion of Anti-??Gal Antibodies. Transplantation 2005; 79:777-82. [PMID: 15818319 DOI: 10.1097/01.tp.0000152662.55720.83] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Nonhuman primates are potential permissive animals for studying the risk of in vivo infection with porcine endogenous retrovirus (PERV). Anti-alphaGal natural antibodies are considered one of the barriers for preventing PERV infection, and it has been postulated that reduction of these antibodies could increase the risk of this infection. The aim of this study was to investigate the role of GAS 914, which depletes anti-alphaGal antibodies, in the potential in vivo transfer of PERV after pig-to-baboon organ xenotransplantation. METHODS Twenty-seven baboons underwent xenotransplantation with hDAF or hMCP/hDAF transgenic pig organs, including heterotopic heart (n = 14) and kidney (n = 13) transplants. All of them received GAS 914 along with different immunosuppression protocols. PERV sequences were investigated by reverse-transcriptase polymerase chain reaction and by polymerase chain reaction assays in samples obtained at autopsy. The presence of PERV-specific antibodies and/or pig xenomicrochimerism was also evaluated. RESULTS PERV RNA was not detected in any baboon plasma sample. In addition, all plasma samples were negative for PERV antibodies. However, PERV DNA sequences were detected in peripheral blood mononuclear cells from 6 of 14 (43%) animals investigated. Porcine mitochondrial DNA was also found in all of these positive samples and in six of the eight (75%) samples with negative PERV DNA, indicating that the detection of PERV sequences was attributable to xenochimerism. PERV-positive cells as a result of xenochimerism were also found in eight of nine (89%) spleen and lymph node tissue samples tested. CONCLUSIONS Sustained depletion of anti-alphaGal antibodies does not augment the risk of PERV infection in pig-to-baboon organ transplantation.
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Affiliation(s)
- Isabel Moscoso
- Unidad de Investigación, C.H.U. Juan Canalejo, Xubias de Arriba, 84, 15006, La Coruña, Spain
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21
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Brandl U, Michel S, Erhardt M, Brenner P, Bittmann I, Rössle M, Baschnegger H, Bauer A, Hammer C, Schmoeckel M, Reichart B. Administration of GAS914 in an orthotopic pig-to-baboon heart transplantation model. Xenotransplantation 2005; 12:134-41. [PMID: 15693844 DOI: 10.1111/j.1399-3089.2005.00208.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Long-term survival of transgenic cardiac xenografts is currently limited by a form of humoral rejection named acute vascular rejection. Preformed and elicited cytotoxic antibodies against Galalpha(1,3)Gal terminating carbohydrate chains, known as the primary cause of hyperacute rejection, are crucial for this process. We investigated whether GAS914, a soluble, polymeric form of a Galalpha(1,3)Gal trisaccharide would sufficiently minimize xenograft rejection of hDAF-transgenic pig hearts orthotopically transplanted into baboons. METHODS Orthotopic heart transplantations were performed using hDAF transgenic piglets as donors and four non-splenectomized baboons as recipients. Baseline immunosuppression consisted of tacrolimus, sirolimus, ATG, steroids. In addition two animals received low-dose GAS914, and two animals high-dose GAS914. One of these baboons received high dose GAS914 and cyclophosphamide induction therapy. Serum levels of anti-Galalpha(1,3)Gal IgM and IgG antibodies, and anti-pig antibodies were controlled daily by anti-Galalpha(1,3)Gal enzyme-linked immunosorbant assay and anti-pig hemolytic assays. Histomorphological (hematoxylin and eosin, elastic van Gieson) and immunohistochemical (IgM, IgG) evaluations were performed on tissue specimens. RESULTS Following low-dose GAS914 therapy survival time was 1 and 9 days, respectively. In baboons treated with high dosages of GAS914 a survival of 30 h and 25 days could be obtained. GAS914 caused an immediate and significant reduction of both anti-Galalpha(1,3)Gal IgM and IgG antibodies. However, sufficient antibody reduction was independent of dosage and form of application of GAS914. A pre-transplant GAS914 treatment was not necessary to effectively reduce antibody levels and prevent hyperacute rejection. In the early postoperative period preformed anti-pig antibodies corresponded predominantly to anti-Galalpha(1,3)Gal antibodies making them susceptible to GAS914. Subsequently, while anti-Galalpha(1,3)Gal antibodies remained low, anti-pig antibodies increased despite of GAS914 application. Corresponding to increased anti-pig antibody titers depositions of IgM and IgG immunoglobulins were detected, which were possibly non-Galalpha(1,3)Gal-specific. CONCLUSIONS Following orthotopic transplantation of hDAF-transgenic pig hearts into baboons, GAS914 is able to maintain a sufficient reduction of Galalpha(1,3)Gal-specific cytotoxicity to the graft. GAS914 therefore is able to prevent not only hyperacute rejection, but also acute vascular rejection at its beginning, when serum cytotoxicity to the pig heart appears to be predominantly Galalpha(1,3)Gal-specific. A sustained prevention of acute vascular rejection, however, still requires the identification of antibody specificities other than to Galalpha(1,3)Gal.
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Affiliation(s)
- Ulrike Brandl
- Department of Cardiac Surgery, Ludwig-Maximilians-University, Munich, Germany.
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22
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Mañez R, Domenech N, Centeno A, Lopez-Pelaez E, Crespo F, Juffe A, Duthaler RO, Katopodis AG. Failure to deplete anti-Galalpha1-3Gal antibodies after pig-to-baboon organ xenotransplantation by immunoaffinity columns containing multiple Galalpha1-3Gal oligosaccharides. Xenotransplantation 2004; 11:408-15. [PMID: 15303977 DOI: 10.1111/j.1399-3089.2004.00152.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The impact of anti-Galalpha1-3Gal (alphaGal) antibodies on the acute humoral xenograft rejection (AHXR) of pig organs transplanted in baboons is unclear. METHODS Twenty-three baboons underwent heterotopic pig heart transplantation (Tx). Groups A (n = 5) and B (n = 6) received non-transgenic and human decay accelerating factor (hDAF) pig hearts, respectively, without any treatment. Groups C (n = 5) and D (n = 7) were transplanted with non-transgenic and hDAF organs, respectively, and the exclusive treatment was repeated extracorporeal immunoadsorptions (EIA) before and after Tx with an alphaGal column containing disaccharide (DI), trisaccharide (TRI) 2 and pentasaccharide (PENTA) oligosaccharides. RESULTS In group A, 3 of 5 xenografts underwent hyperacute rejection (HAR). No xenograft from groups B, C and D experienced HAR, most of them failing from AHXR. Immediately after Tx and up to day 2, the level of immunoglobulin (Ig)M and IgG anti-alphaGal DI, TRI2 and TRI6, and anti-pig hemolytic antibody (APHA) antibodies decreased in all the groups by 80 to 96% compared with the concentration present before Tx. From day 3 to AHXR, a sustained increase of anti-alphaGal IgM DI, TRI2 and TRI6, and APHA occurred in all groups. EIA depleted anti-alphaGal IgM and APHA before Tx, but it did not modify the increase of these antibodies after Tx. Baboon serum samples before Tx, pre-incubated in vitro with 1 mg/ml of DI, TRI2 and TRI6, had an average of 93% reduction of anti-alphaGal IgM antibodies specific against each one of these alphaGal oligosaccharides. In contrast, at AHXR, the average reduction after in vitro pre-incubation with either 1 or 5 mg/ml of DI, TRI2 and TRI6 was 40%. CONCLUSIONS The EIA reduces anti-alphaGal and APHA antibodies, preventing the HAR of non-transgenic pig hearts transplanted in baboons, as does hDAF expression. However, EIA does not modify the level of anti-alphaGal IgM and APHA antibodies after Tx nor the AHXR of either non-transgenic or hDAF pig organs. The increase in anti-alphaGal IgM after Tx was similar for the different antibodies of the anti-alphaGal polymorphism, and was only partially neutralized in vitro with the specific alphaGal oligosaccharide.
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Affiliation(s)
- Rafael Mañez
- Transplantation Division, Complejo Hospitalario Universitario Juan Canalejo, La Coruña, Spain.
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23
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Kuwaki K, Knosalla C, Moran K, Alt A, Katopodis AG, Duthaler RO, Schuurman HJ, Awwad M, Cooper DKC. Reduction of anti-Galα1,3Gal antibodies by infusion of types 2 and 6 gal trisaccharides conjugated to poly-l-lysine. Xenotransplantation 2004; 11:210-5. [PMID: 14962283 DOI: 10.1046/j.1399-3089.2003.00096.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To investigate the specificity of anti-Galalpha1,3Gal (Gal) antibodies (Abs) with respect to Gal oligosaccharides of types 2 and 6, eight baboons received an intravenous infusion of either a poly-l-lysine conjugate of Gal type 2 (n = 5) or type 6 (n = 3), followed 48 h later by the alternative Gal type 6 or 2 conjugate, respectively. IgM Abs reactive to Gal type 2 were depleted by 80 to 89% by either Gal conjugate. IgM reactive to Gal type 6 was less efficiently depleted by the Gal type 2 conjugate (57% depletion) than the Gal type 6 (82% depletion). Gal-reactive IgG was depleted more slowly and less efficiently by either glycoconjugate (initially by only 28 to 54%). Our results indicate that the Gal type 6 conjugate depletes most anti-Gal IgM, but the Gal type 2 conjugate is less efficient in depleting anti-Gal IgM reactive with type 6. There remain small fractions of antibody that are unadsorbed, particularly of IgG, probably due to their low affinity and distribution in both the intra- and extra-vascular compartments.
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Affiliation(s)
- K Kuwaki
- Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02129, USA
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24
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Liu J, Weintraub A, Holgersson J. Multivalent Galalpha1,3Gal-substitution makes recombinant mucin-immunoglobulins efficient absorbers of anti-pig antibodies. Xenotransplantation 2003; 10:149-63. [PMID: 12588648 DOI: 10.1034/j.1399-3089.2003.01144.x] [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: 11/23/2022]
Abstract
Hyperacute organ xenograft rejection can be prevented by removing anti-pig antibodies by extracorporeal absorption prior to transplantation. A novel recombinant absorber of anti-pig antibodies was developed by fusing the cDNA encoding the extracellular part of a mucin-type protein, P-selectin glycoprotein ligand-1, with an antibody Fc fragment cDNA, which upon coexpression with the porcine alpha1,3 galactosyltransferase carried the xenogeneic epitope, Galalpha1,3Gal (Liu J., Qian Y., Holgersson J., Transplantation 1997, 63, 1673-1682). The biochemical characterization of the mucin/Ig and its absorption efficacy compared with that of porcine thyroglobulin and Galalpha1,3Gal-conjugated beads are reported. The carbohydrate portion of the mucin/Ig constituted 43% of its molecular weight and the majority of the Galalpha1,3Gal epitopes were O-linked as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting following N-glycosidase F digestion. Gas chromatography-mass spectrometry of reduced and acetylated saccharides released by alpha-galactosidase treatment revealed that the fusion protein carried approximately 140 mol of terminal, alpha-linked galactose per mole protein. Based on the reduction in pig aortic endothelial cell cytotoxicity, Galalpha1,3Gal-substituted mucin/Igs on agarose beads were, on a carbohydrate molar basis, shown to be approximately 20 times more efficient than agarose-conjugated pig thyroglobulin, and approximately 5000 and 30,000 times more efficient than Galalpha1,3Gal-substituted agarose and macroporous glass beads, respectively. Structural features of the mucin backbone and its carbohydrate core saccharide chains determine the structural context, spatial orientation and spacing of Galalpha1,3Gal epitopes and are likely to explain the superior absorption efficacy of the recombinant mucin-type chimera.
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Affiliation(s)
- Jining Liu
- Division of Clinical Immunology, Karolinska Institutet, Huddinge University Hospital AB, Stockholm, Sweden
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25
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Sharma A, Naziruddin B, Cui C, Martin MJ, Xu H, Wan H, Lei Y, Harrison C, Yin J, Okabe J, Mathews C, Stark A, Adams CS, Houtz J, Wiseman BS, Byrne GW, Logan JS. Pig cells that lack the gene for alpha1-3 galactosyltransferase express low levels of the gal antigen. Transplantation 2003; 75:430-6. [PMID: 12605105 DOI: 10.1097/01.tp.0000053615.98201.77] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The major antigen recognized on pig tissue by primate antibodies is a terminal galalpha1-3gal carbohydrate structure (gal antigen) present on glycolipids and glycoproteins. The production of animals from somatic cells allows for the inactivation of specific genes. It is anticipated that the complete inactivation of the gene encoding alpha1-3 galactosyltransferase, the enzyme that synthesizes the galalpha1-3gal linkage, will result in loss of that antigen from pig organs and tissue and will provide a survival benefit in pig-to-primate xenotransplants. METHODS Positive-negative selection was used to produce fetal-pig fibroblasts that were a heterozygous knockout (+/-) of the alpha1-3 galactosyltransferase gene. Nuclear transfer of these cells generated pig embryos and live born pigs with the appropriate genotype. Using a novel selection method with cells from (+/-) embryos, we produced homozygous (-/-) fetal-pig fibroblast cells. RESULTS Southern blot analysis of the alpha1-3 galactosyltransferase gene showed that we had produced (+/-) pig embryos, (+/-) live born pigs, and (-/-) pig-fetal fibroblast cells. Fluorescence-activated cell sorter (FACS) analysis with some, but not all, mouse anti-gal monoclonal antibodies and sensitized human serum showed that (-/-) cells still synthesized the gal antigen at 1 to 2% of the level of control heterozygous cells. CONCLUSIONS Fetal-pig fibroblasts homozygous for the knockout of the alpha1-3 galactosyltransferase gene appear to express low but detectable levels of the gal antigen.
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Affiliation(s)
- Ajay Sharma
- Nextran Incorporated, Princeton, NJ 08540, USA
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26
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Xu H, Yin D, Naziruddin B, Chen L, Stark A, Wei Y, Lei Y, Shen J, Logan JS, Byrne GW, Chong ASF. The in vitro and in vivo effects of anti-galactose antibodies on endothelial cell activation and xenograft rejection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:1531-9. [PMID: 12538718 DOI: 10.4049/jimmunol.170.3.1531] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously produced a series of antigalactose (anti-Gal) hybridomas and characterized their heavy chain gene usage. Here we have quantified the affinity of these Abs for the alpha-Gal epitope and characterized their in vitro effects on endothelial cell activation and apoptosis. We report that anti-Gal mAbs derived from Gal(-/-) mice show a range of affinity for the alpha-Gal epitope, and that affinity was generally increased as the V(H) gene usage transitioned from germline sequences to sequences exhibiting somatic maturation. Despite an 85-fold range in affinity, all the anti-Gal mAbs examined induced alpha-Gal-specific endothelial cell activation, and after prolonged exposure induced endothelial cell apoptosis in a complement-independent manner. Only murine anti-Gal mAbs of the IgM or IgG3 subclass, but not IgG1, were effective at initiating complement-dependent cell lysis. Using a novel rat to mouse xenograft model, we examined the in vivo ability of these mAbs to induce xenograft rejection and characterized the rejection using histology and immunohistochemistry. Infusion of complement-fixing IgG3 mAbs resulted in either hyperacute rejection or acute vascular rejection of the xenograft. Surprisingly, infusion of an equal amount of a high affinity anti-Gal IgG1 mAb, that fixed complement poorly also induced a rapid xenograft rejection, which we have labeled very acute rejection. These studies emphasize the importance of in vivo assays, in addition to in vitro assays, in understanding the role of anti-Gal IgG-mediated tissue injury and xenograft rejection.
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MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/metabolism
- Antibodies, Monoclonal/pharmacology
- Antibody Affinity/genetics
- Apoptosis/genetics
- Apoptosis/immunology
- Binding Sites, Antibody/genetics
- Cell Line
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- Disaccharides/deficiency
- Disaccharides/genetics
- Disaccharides/immunology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/immunology
- Endothelium, Vascular/metabolism
- Erythrocytes/immunology
- Erythrocytes/metabolism
- Graft Rejection/genetics
- Graft Rejection/immunology
- Graft Rejection/pathology
- Heart Transplantation/immunology
- Heart Transplantation/pathology
- Humans
- Hybridomas
- Injections, Intravenous
- Mice
- Mice, Knockout
- Nuclear Proteins
- Rats
- Rats, Inbred Lew
- Swine
- Transplantation, Heterologous/immunology
- Transplantation, Heterologous/pathology
- Transplantation, Heterotopic/immunology
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Affiliation(s)
- Hui Xu
- Nextran, Princeton, NJ 08540, USA
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27
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Katopodis AG, Warner RG, Duthaler RO, Streiff MB, Bruelisauer A, Kretz O, Dorobek B, Persohn E, Andres H, Schweitzer A, Thoma G, Kinzy W, Quesniaux VFJ, Cozzi E, Davies HFS, Mañez R, White D. Removal of anti-Galalpha1,3Gal xenoantibodies with an injectable polymer. J Clin Invest 2003. [PMID: 12488437 DOI: 10.1172/jci200216526] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Preformed and elicited Ab's against the Galalpha1,3Gal terminating carbohydrate chains (alphaGal Ab's) are the primary cause of hyperacute and acute vascular xenograft rejection in pig-to-primate transplantation. alphaGal Ab's are produced by long-lived Ab-producing cells that are not susceptible to pharmacological immunosuppression. We reasoned that antigen-specific elimination of alphaGal Ab's might be achieved in vivo by systemic administration of nonimmunogenic polyvalent alphaGal structures with high avidity for alphaGal Ab's. We devised GAS914, a soluble trisaccharide-polylysine conjugate of approximately 500 kDa that effectively competes for alphaGal binding by alphaGal IgM (IC(50), 43 nM) and IgG (IC(50), 28 nM) in vitro. Injections of GAS914 in cynomolgus monkeys, at the dose of 1 mg/kg, resulted in the immediate decrease of more than 90% of circulating alphaGal Ab's and serum anti-pig cytotoxicity. In baboons, repeated injections of GAS914 effectively reduced both circulating alphaGal Ab's and cytotoxicity over several months. Studies with [(14)C]GAS914 in rhesus monkeys and Gal(-/-) mice indicate that GAS914 binds to circulating alphaGal Ab's and that the complex is quickly metabolized by the liver and excreted by the kidney. Remarkably, posttreatment alphaGal Ab titers never exceeded pretreatment levels and no sensitization to either alphaGal or the polylysine backbone has been observed. Furthermore there was no apparent acute or chronic toxicity associated with GAS914 treatment in primates. We conclude that GAS914 may be used therapeutically for the specific removal of alphaGal Ab's.
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Affiliation(s)
- Andreas G Katopodis
- Novartis Institutes for Biomedical Research, Transplantation Research, Basel, Switzerland.
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28
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Katopodis AG, Warner RG, Duthaler RO, Streiff MB, Bruelisauer A, Kretz O, Dorobek B, Persohn E, Andres H, Schweitzer A, Thoma G, Kinzy W, Quesniaux VFJ, Cozzi E, Davies HFS, Mañez R, White D. Removal of anti-Galalpha1,3Gal xenoantibodies with an injectable polymer. J Clin Invest 2002; 110:1869-77. [PMID: 12488437 PMCID: PMC151655 DOI: 10.1172/jci16526] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Preformed and elicited Ab's against the Galalpha1,3Gal terminating carbohydrate chains (alphaGal Ab's) are the primary cause of hyperacute and acute vascular xenograft rejection in pig-to-primate transplantation. alphaGal Ab's are produced by long-lived Ab-producing cells that are not susceptible to pharmacological immunosuppression. We reasoned that antigen-specific elimination of alphaGal Ab's might be achieved in vivo by systemic administration of nonimmunogenic polyvalent alphaGal structures with high avidity for alphaGal Ab's. We devised GAS914, a soluble trisaccharide-polylysine conjugate of approximately 500 kDa that effectively competes for alphaGal binding by alphaGal IgM (IC(50), 43 nM) and IgG (IC(50), 28 nM) in vitro. Injections of GAS914 in cynomolgus monkeys, at the dose of 1 mg/kg, resulted in the immediate decrease of more than 90% of circulating alphaGal Ab's and serum anti-pig cytotoxicity. In baboons, repeated injections of GAS914 effectively reduced both circulating alphaGal Ab's and cytotoxicity over several months. Studies with [(14)C]GAS914 in rhesus monkeys and Gal(-/-) mice indicate that GAS914 binds to circulating alphaGal Ab's and that the complex is quickly metabolized by the liver and excreted by the kidney. Remarkably, posttreatment alphaGal Ab titers never exceeded pretreatment levels and no sensitization to either alphaGal or the polylysine backbone has been observed. Furthermore there was no apparent acute or chronic toxicity associated with GAS914 treatment in primates. We conclude that GAS914 may be used therapeutically for the specific removal of alphaGal Ab's.
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Affiliation(s)
- Andreas G Katopodis
- Novartis Institutes for Biomedical Research, Transplantation Research, Basel, Switzerland.
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29
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Dehoux JP, de la Parra B, Latinne D, Bazin H, Gianello P. Characterization of baboon anti-porcine IgG antibodies during acute vascular rejection of porcine kidney xenograft. Xenotransplantation 2002; 9:338-49. [PMID: 12199865 DOI: 10.1034/j.1399-3089.2002.01090.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the pig-to-baboon model, the removal of anti-porcine natural antibodies abrogates hyperacute vascular rejection (HAVR), but the xenograft then undergoes an acute vascular rejection (AVR) concomitantly to the appearance of newly formed anti-porcine antibodies. The use of anti-IgM monoclonal antibody (mAb) in baboons allowed to avoid HAVR of pig-to-baboon renal xenografts, but, at post-operative day 6, AVR occurred because of a rapid return of anti-porcine antibodies. The aim of this work was to characterize the anti-porcine antibodies during AVR. Sera from anti-IgM-treated animals were assessed prior to the graft and at the time of AVR by enzyme linked immunosorbent assay (ELISA) to determine anti-porcine antibodies concentration as well as the IgG subtypes. The same sera were tested on confluent cultures of porcine aortic endothelial cells (PAECs) to assess (i) the cytolytic complement-dependent activity and (ii) the E-selectin expression. The K affinity of anti-Gal IgG antibodies was measured by ELISA. Anti-porcine (Gal and non-Gal) IgG antibodies were tested on PAECs by flow cytometry to discriminate the presence of Gal epitopes from the recognition of other porcine epitopes. We found that both anti-porcine IgM and IgG antibodies presented a significantly increased cytolytic activity and E-selectin expression on PAECs during AVR. These characteristics are related to an important increase of the antibody (Ab) titer (especially anti-galactosyl) and a switch to anti-galactosyl IgG1 subclass production, whereas the K affinity remained unchanged. The deleterious effects of both IgM and IgG antibodies observed during AVR showed the crucial need for treatment controlling the cells producing anti-porcine antibodies.
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MESH Headings
- Animals
- Antibodies, Anti-Idiotypic/pharmacology
- Antibodies, Anti-Idiotypic/therapeutic use
- Antibodies, Heterophile/biosynthesis
- Antibodies, Heterophile/immunology
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Antibody Affinity
- Antibody Specificity
- Aorta/cytology
- Cells, Cultured/immunology
- Cells, Cultured/transplantation
- Disaccharides/immunology
- E-Selectin/analysis
- Endothelium, Vascular/chemistry
- Endothelium, Vascular/immunology
- Endothelium, Vascular/transplantation
- Epitopes/immunology
- Graft Rejection/immunology
- Graft Rejection/therapy
- Graft Survival
- Immunization, Passive
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/immunology
- Immunoglobulin M/immunology
- Kidney Transplantation/immunology
- Papio/immunology
- Swine/immunology
- Transplantation, Heterologous/immunology
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Affiliation(s)
- Jean-Paul Dehoux
- Laboratory of Experimental Surgery, Faculty of Medicine, Université Catholique de Louvain, ESP, Clos Chapelle aux Champs, Brussels, Belgium
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30
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Saethre M, Sølvik UØ, Haraldsen G, Fiane AE, Boretti E, Thorsby E, Platt JL, Mollnes TE. Human serum-induced porcine endothelial cell E-selectin expression is associated with IgG3 and IgM anti-Gal antibodies. Xenotransplantation 2002; 9:350-8. [PMID: 12199866 DOI: 10.1034/j.1399-3089.2002.01094.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Naturally occurring anti-Galalpha1-3Gal (anti-Gal) antibodies and complement induce hyperacute rejection (HAR) of porcine organs transplanted to primates. If the hyperacute reaction is prevented, an acute vascular rejection (AVR) occurs within hours to few days. Antibodies are important for the development of AVR, whereas the role of complement is still not clarified. AVR is characterized by protein synthesis-dependent endothelial cell (EC) activation. In the present study we investigated the relation between EC activation as measured by E-selectin expression, and the concentrations of anti-Gal antibodies of IgM, IgG and IgG subclasses in sera from 80 healthy blood donors selected on the basis of sex and age. There was a significant correlation between E-selectin expression and the concentration of IgG3 anti-Gal (r=0.39; P=0.019), which was not seen for the other IgG subclasses or for total IgG anti-Gal. A modest, but significant correlation was found between the concentration of IgM anti-Gal and E-selectin expression (r=0.38; P=0.040), but not between IgM and IgG3 anti-Gal. There was a large interindividual variation in anti-Gal antibodies, 50-fold for IgM and 70-fold for IgG. Females had significantly higher concentrations of IgM anti-Gal than males (P=0.0006), which was explained by a substantial increase in IgM anti-Gal concentration in younger women. The concentration of IgG anti-Gal and the degree of E-selectin expression did not differ between sex or age groups. In conclusion, the close correlation between anti-Gal antibodies of the potent complement activating IgG3 subclass and porcine EC activation, may imply that these antibodies play a role in EC activation characteristic of AVR.
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31
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Tinguely C, Schaller M, Carrel T, Nydegger UE. Spectrotype analysis and clonal characteristics of human anti-Gal alpha1-3Gal antibodies. Xenotransplantation 2002; 9:252-9. [PMID: 12060461 DOI: 10.1034/j.1399-3089.2002.00148.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Galalpha1-3Gal (anti-Gal), a polyclonal so-called natural antibody (Ab), is present in large amounts in human serum not only as IgG-, but also as IgM- and IgA-isotypes. It has gained a particular interest in the context of xenotransplantation, because the endothelial pig cells express the terminal Galalpha1-3Gal determinant on several adhesion molecules. Little is known of it's function and direct examination of the structure of the Ig genes responsible for coding anti-Gal is lacking. We used the technique of isoelectric focussing (IEF)/affinity immunoblotting for direct analysis of the clonal distribution and spectrotype analysis of IgM- and IgG anti-Gal. By single cell analysis of magnetic bead and fluorescent-activated cell sorter (FACS) isolated mature anti-Gal bearing human B cells from whole blood we analyzed the VH gene families involved in anti-Gal production. Oligoclonal and individually distinct IgG banding patterns were found with isoelectric points between 4 and 9. IgM spectrotypes revealed to be more uniform with a polyclonal banding pattern of more than 12 bands at a pH between 4.7 and 7. IgG- and IgM-banding patterns over a period of 6 months remained unchanged. Single cell polymerase chain reaction (PCR), with all family specific primers, revealed the use of the VH2f gene family for the IgG2 isoptype. The differences found in the spectrotype banding patterns of IgG and IgM could be explained by the suggestion that anti-Gal IgM were produced by the use of unmutated germline genes and the possibility of the absence of somatic mutations. The greater clonal heterogeneity in the IgG population could be explained by somatic hypermutations during the switch from IgM to IgG. The use of this VH2f gene family, which is also involved in the generation of Abs against bacterial pathogens, could mean that this is a predominant region used for the generation of such natural occurring antibodies.
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Affiliation(s)
- Caroline Tinguely
- Department of Hematology, Bern University Hospital, Bern, Switzerland
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32
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Diamond LE, Byrne GW, Schwarz A, Davis TA, Adams DH, Logan JS. Analysis of the control of the anti-gal immune response in a non-human primate by galactose alpha1-3 galactose trisaccharide-polyethylene glycol conjugate. Transplantation 2002; 73:1780-7. [PMID: 12085001 DOI: 10.1097/00007890-200206150-00014] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The current limitation to the clinical application of xenotransplantation using pig organs is a rejection process that has been termed delayed xenograft rejection or acute vascular rejection. It is thought that acute vascular rejection may be mediated at least in part by both the continued synthesis, of preexisting, and the induction, posttransplantation, of antibodies against the carbohydrate moiety galalpha1-3gal that is present on glycoproteins and glycolipids of the pig endothelium. The synthesis of these antibodies has proven difficult to control with currently available immunosuppressive agents. METHODS We have synthesized galalpha1-3gal conjugated polyethylene glycol polymers that can bind to anti-galalpha1-3gal antibodies and tested their activity in non-human primates. RESULTS These conjugates when administered to non-human primates can substantially reduce the levels of preexisting and control the induction of anti-galalpha1-3gal antibodies. The level of circulating antibody-secreting cells that make anti-galalpha1-3gal antibodies is also reduced. CONCLUSION These alpha-gal polyethylene glycol conjugates may have the potential to control the anti-gal antibody response in a pig to primate organ transplant setting and may be a useful therapeutic agent in prolonging graft survival.
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Affiliation(s)
- Lisa E Diamond
- Nextran Inc., 303B College Road East, Princeton, NJ 08540, USA
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33
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Roos A, Daha MR. Antibody-mediated activation of the classical complement pathway in xenograft rejection. Transpl Immunol 2002; 9:257-70. [PMID: 12180840 DOI: 10.1016/s0966-3274(02)00042-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Transplant rejection is a multifactorial process involving complex interactions between components of the innate and the acquired immune system. In view of the shortage of donor organs available for transplantation, xenotransplantation of pig organs into man has been considered as a potential solution. However, in comparison to allografts, xenografts are subject to extremely potent rejection processes that are currently incompletely defined. Consequently, an appropriate and safe treatment protocol ensuring long-term graft survival is not yet available. The first barrier that has to be taken for a xenograft is hyperacute rejection, a rapid process induced by the binding of pre-formed antibodies from the host to the graft endothelium, followed by activation of the classical complement pathway. The present review concentrates on the role of antibodies and complement in xenograft rejection as well as on the approaches for treatment that target these components. The first part focuses on porcine xenoantigens that are recognized by human xenoreactive antibodies and the different treatment strategies that aim on interference in antibody binding. The second part of the review deals with complement activation by xenoreactive antibodies, and summarizes the role of complement in the induction of endothelial cell damage and cell activation. Finally, various options that are currently under development for complement inhibition are discussed, with special reference to the specific inhibition of the classical complement pathway by soluble complement inhibitors.
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Affiliation(s)
- Anja Roos
- Department of Nephrology, Leiden University Medical Center, The Netherlands.
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34
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Teranishi K, Gollackner B, Bühler L, Knosalla C, Correa L, Down JD, White-Scharf ME, Sachs DH, Awwad M, Cooper DKC. Depletion of anti-gal antibodies in baboons by intravenous therapy with bovine serum albumin conjugated to gal oligosaccharides. Transplantation 2002; 73:129-39. [PMID: 11792992 DOI: 10.1097/00007890-200201150-00024] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Anti-Galalpha 1-3Gal (Gal) antibodies (Ab) play a key role in the rejection of pig cells or organs transplanted into primates. A course of extracorporeal immunoadsorption (EIA) of anti-Gal Ab using an immunoaffinity column of a Gal type 6 oligosaccharide depletes Ab successfully, but Ab returns during the next few days. Although therapy with an anti-CD154 monoclonal antibody (mAb) prevents an induced Ab response to Gal or non-Gal epitopes, T cell-independent natural anti-Gal IgM and IgG return to baseline (pretransplant) levels. We have investigated the capacity of continuous i.v. infusion of bovine serum albumin conjugated to Gal type 6 oligosaccharide (BSA-Gal) to deplete or maintain depletion of circulating anti-Gal Ab. METHODS Porcine peripheral blood mobilized progenitor cells (PBPC) obtained by leukapheresis from MHC-inbred miniature swine (n=6) were transplanted into baboons. Group 1 baboons (n=4) underwent whole body (300 cGy) and thymic (700 cGy) irradiation, T cell depletion with antithymocyte globulin, complement depletion with cobra venom factor, short courses of anti-CD154 mAb therapy (20 mg/kg i.v. on alternate days), cyclosporine (CyA) (in two baboons only), mycophenolate mofetil, and porcine hematopoietic growth factors. Anti-Gal Ab depletion by EIA was carried out before transplantation of high doses (2-4x 1010 cells/kg) of PBPC. Group 2 baboons (n=3) received the group 1 regimen (including CyA) plus a continuous i.v. infusion of BSA-Gal. To prevent sensitization to BSA, anti-CD154 mAb therapy was continued until BSA-Gal administration was discontinued. RESULTS In group 1, Gal-reactive Ab returned to pre-PBPC transplant levels within 15-21 days, but no induced Ab to Gal or non-Gal determinants developed while anti-CD154 mAb therapy was being administered. In group 2, anti-Gal Ab was either not measurable or minimally measurable while BSA-Gal was being administered. After discontinuation of BSA-Gal, Ab did not return to pre-PBPC transplant level for more than 40-60 days, and no sensitization developed even when all therapy was discontinued. In one baboon, however, Ab to Gal type 2, but not type 6, returned during BSA-Gal therapy. CONCLUSIONS Prevention of the induced humoral response to Gal and non-Gal epitopes by anti-CD154 mAb therapy has been reported previously by our group, but our studies are the first to demonstrate a therapy that resulted in an absence of natural anti-Gal Ab for a prolonged period. The combination of BSA-Gal and T cell costimulatory blockade may facilitate survival of pig cells and organs transplanted into primates. The return in one baboon of Ab reactive with the Gal type 2 oligosaccharide, but not type 6, indicates some polymorphism of anti-Gal Ab and suggests that, to be effective in all cases, the infusion of a combination of type 6 and type 2 BSA-Gal may be required.
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Affiliation(s)
- K Teranishi
- Transplantation Biology Research Center, Massachusetts General Hospital, MGH East, Building 149-9019, 13th Street, Boston, MA 02129, USA
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35
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Nozawa S, Xing PX, Wu GD, Gochi E, Kearns-Jonker M, Swensson J, Starnes VA, Sandrin MS, McKenzie IF, Cramer DV. Characteristics of immunoglobulin gene usage of the xenoantibody binding to gal-alpha(1,3)gal target antigens in the gal knockout mouse. Transplantation 2001; 72:147-55. [PMID: 11468550 DOI: 10.1097/00007890-200107150-00028] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Natural antibodies that react with galactose-alpha(1,3)galactose [galalpha(1,3)gal] carbohydrate epitopes exist in humans and Old World primates because of the inactivation of the alpha1,3-galactosyltransferase (alpha1,3GT) gene in these species and the subsequent production of antibodies to environmental microbes that express the galalpha(1,3)gal antigen. The Gal knockout (Gal o/o) mouse, produced by homologous disruption of the alpha1,3GT gene, spontaneously makes anti-galalpha(1,3)gal antibodies and can be used to study the genetic control of humoral immune responses to this carbohydrate epitope. METHODS Six hybridomas that produce monoclonal antibodies (mAbs) to galalpha(1,3)gal were generated in Gal o/o mice. The mAbs were tested to characterize the binding activity with flow cytometry using pig aortic endothelial cells and ELISA with galalpha(1,3)gal carbohydrates. The VH and VK genes of these hybridomas were cloned, sequenced, and analyzed. RESULTS The mAbs showed distinct patterns of antibody binding to galalpha(1,3)gal antigens. The VH genes that encode the mAb binding activity were restricted to a small number of genes expressed in their germline configuration. Four of six clones used closely related progeny of the same VH germline gene (VH441). Comparison of the mouse gene VH441 to the human gene IGHV3-11, a gene that encodes antibody activity to galalpha(1,3)gal in humans, demonstrates that these two genes share a nonrandom distribution of amino acids used at canonical binding sites within the variable regions (complimentary determining regions 1 and 2) of their immunoglobulin VH genes. CONCLUSIONS These results demonstrate the similarity of the Gal o/o mice and humans in their immune response to galalpha(1,3)gal epitopes. Gal o/o mouse can serve as a useful model for examining the genetic control of antibody/antigen interactions associated with the humoral response to pig xenografts in humans.
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Affiliation(s)
- S Nozawa
- Transplantation Biology Research Laboratory, Division of Cardiothoracic Surgery, The Keck School of Medicine, University of Southern California, Los Angeles 90027, USA
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Schwardt O, Baisch G, Ohrlein R. Synthesis of linear-B saccharopeptides via enzymatic galactosylation of non-natural glucosamide acceptors. Bioorg Med Chem 2001; 9:1857-69. [PMID: 11425588 DOI: 10.1016/s0968-0896(01)00086-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A series of D- and L-glycopyranuronic acids are coupled to glucosamines to give saccharopeptides. These 'disaccharides', in which the acetyl moiety of the natural N-acetyl-glucosamine is replaced by various sugar acids, turned out to be surprisingly good substrates for beta(1-4)-galactosyl-transferase and alpha(1-3)-galactosyl-transferase. The enzymes transfer successively two galactose units from the donor UDP-galactose onto these acceptor substrates, despite the far reaching alterations, regio- and stereospecifically in the expected manner to give linear-B saccharopeptides.
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Affiliation(s)
- O Schwardt
- Novartis Pharma AG, Postfach, CH-4002 Basel, Switzerland.
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37
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Gerber B, Tinguely C, Bovin NV, Rieben R, Nydegger UE. Differences between synthetic oligosaccharide immunoabsorbents in depletion capacity for xenoreactive anti-Galalpha1-3Gal antibodies from human serum. Xenotransplantation 2001; 8:106-14. [PMID: 11328581 DOI: 10.1034/j.1399-3089.2001.00064.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Extracorporeal immunoabsorption for removal of anti-Galalpha1-3Gal (anti-Gal) antibodies in putative pig-to-human xenotransplantation is considered a major prophylactic measure to avoid hyperacute and acute vascular rejections. However, the efficacy of the procedure does depend on choosing the appropriate oligosaccharide epitopes for the binding of human anti-Gal. The synthetic oligosaccharides Galalpha1-3Gal (B-disaccharide, Bdi) and Galalpha1-3Galbeta1-4Glc ('type 6' trisaccharide, Tri6), covalently coupled to Sepharose via polyacrylamide (Sorbents Bdi and -Tri6, respectively), as well as a mixture thereof (Sorbent Mix), were examined for their efficacy to absorb anti-Gal from 20 human serum samples. Sorbent Bdi removed 81% of anti-Gal IgM and 85% of -IgG when assessed on Bdi by ELISA, but only 49% of IgG and 75% of IgM when assessed on Tri6. Sorbent Tri6 and -Mix showed significantly better absorption capacities in so far as Sorbent Tri6 removed 65% of anti-Gal IgM and 80% of -IgG as assessed on Bdi and 85% of IgM/87% of IgG when tested on Tri6, and Sorbent Mix absorbed > 90% anti-Gal of both isotypes of either specificity. Direct hemagglutination of rabbit erythrocytes (ER) was reduced by 75% (median value, range 0-94%) and the median cytotoxicity to PK15 target cells by > 94% after absorption on Sorbent Mix. Neither the decrease in ER agglutination titers nor the reduction of PK15 cytotoxicity revealed significant differences between the three immunoabsorbents tested. The large variation ranges of absorption efficacies within the 20 tested sera suggest that "tailor-made" immunoabsorption treatments may be needed for putative xenotransplant recipients.
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Affiliation(s)
- B Gerber
- Department of Hematology, Bern University Hospital, CH-3010 Bern, Switzerland
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38
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Roos A, Essers M, van Gijlswijk-Janssen D, Bovin NV, Daha MR. Both IgG and IgM anti-pig antibodies induce complement activation and cytotoxicity. Xenotransplantation 2001; 8:3-14. [PMID: 11208186 DOI: 10.1046/j.0908-665x.2000.00087.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hyperacute rejection of pig xenografts transplanted in humans is caused by endothelial cell binding of pre-formed xenoreactive antibodies (XAb) and activation of the classical pathway of complement. Human XAb mainly consist of anti-Galalpha1 3Gal antibodies, which occur in IgM, IgG and IgA classes. Whereas IgM anti-Galalpha1 3Gal antibodies have an established role in hyperacute rejection, the potential role of IgG XAb in this process is still controversial. The aim of the present study was to assess the specificity and functional properties of IgG and IgM XAb. Both classes were present in all human plasma samples tested, with a high inter-individual variability. Levels of IgG XAb did not correlate with levels of IgM XAb. Binding to Galalpha1 3Gal is strongly correlated with binding to the pig cell line PK15, both for IgG and for IgM, pointing to Galalpha1 3Gal as the major antigen recognized. Both purified IgM and IgG induced C3 deposition on PK15 cells and complement-dependent cytotoxicity in a dose-dependent way. The combination of IgG and IgM XAb resulted in an additive effect on cytotoxicity. Affinity-purified IgG anti-Galalpha1 3Gal antibodies were 22 times less potent than IgM in induction of cytotoxicity. These results indicate a quantitative, but not a qualitative, difference between IgM and IgG anti-pig antibodies concerning their complement-activating properties. Therefore, both classes of XAb are of importance in the pathogenesis of hyperacute rejection, and the relative importance of each class may differ considerably between individual patients, depending on the ratio of IgG and IgM XAb present in serum.
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Affiliation(s)
- A Roos
- Department of Nephrology, Leiden University Medical Center, The Netherlands.
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39
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Magnusson S, Strokan V, Mölne J, Nilsson K, Rydberg L, Breimer ME. Blocking of human anti-pig xenoantibodies by soluble GALα1-3GAL and Galα1-2GAL disaccharides; studies in a pig kidney in vitro perfusion model. Transpl Int 2000. [DOI: 10.1111/j.1432-2277.2000.tb01018.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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McKane W, Lee J, Preston R, van Dam M, Cairns T, Taube D. IgG2 anti-Galalpha1-3Gal does not induce porcine aortic endothelial cell accommodation in vitro. Transplantation 2000; 70:1085-93. [PMID: 11045647 DOI: 10.1097/00007890-200010150-00016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Xenografts that have been protected from hyperacute rejection (HAR) are termed accommodated if they are not then rejected despite the presence of xenoantibody. It has been proposed that IgG may confer resistance to complement dependent cytotoxicity (CDC), a conventional in vitro marker of accommodation. We hypothesized that noncytotoxic IgG2 anti-Galalpha1-3Gal was responsible for this effect. METHODS AND RESULTS We purified IgG anti-Galalpha1-3Gal from pooled human normal immunoglobulin and three sera, by elution from protein G and Galalpha1-3Gal-R immunoadsorbents. The eluates were IgM free and > or =95% IgG2. They bound to Galalpha1-3Gal, porcine aortic endothelial cells (PAEC) and lymphocytes. It was not possible to block IgM binding to PAEC or lymphocytes using IgG anti-Galalpha1-3Gal (200 microg/ml). The eluates were noncytotoxic in micro-CDC assays. To investigate accommodation, PAEC were cultured with subsaturating doses of the four IgG eluates for up to 144 hr. Resistance of nontrypsinized PAEC to CDC by human serum was measured in a cell viability assay. PAEC were not rendered resistant to CDC in any of the experiments. To investigate the possibility that accommodation might be induced by non-Galalpha1-3Gal IgG, the experiments were repeated using HNIg, again with no protection demonstrated. CONCLUSIONS Using primary PAEC monolayers, we were unable to induce resistance to CDC with human normal immunoglobulin and its IgG2 anti-Gabeta1-3Gal subset. This contradicts previous experiments using trypsinized, immortalized cells. Although resistance to CDC is not an ideal marker of accommodation, the detrimental effects of IgG make it unlikely that it will become a useful clinical means of inducing accommodation.
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Affiliation(s)
- W McKane
- The Brent Laboratory, St Mary's Hospital, London, UK
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41
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Bouhours D, Liaigre J, Naulet J, Bovin NV, Bouhours JF. A novel pentaglycosylceramide in ostrich liver, IV4-beta-Gal-nLc4Cer, with terminal Gal(beta1-4)Gal, a xenoepitope recognized by human natural antibodies. Glycobiology 2000; 10:857-64. [PMID: 10988247 DOI: 10.1093/glycob/10.9.857] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thin layer chromatograms of ostrich liver neutral glycosphingolipids were immunostained with human sera. In addition to the expected staining of the Forssman pentaglycosylceramide by some sera, more polar and less abundant unknown glycolipids could be stained. Among them, the shortest carbohydrate chain glycolipid was purified and structurally characterized by mass spectrometry, proton NMR and methylation analysis. It was a novel pentaglycosylceramide of the neolactoseries terminated with the Gal(beta1-4)Gal determinant which is not expressed in mammalian species. Human antibodies affinity-purified on a synthetic Gal(beta1-4)Gal(beta1-4)Glc-Sepharose column recognized the newly characterized Gal(beta1-4)Gal-terminated pentaglycosylceramide, and, in addition, longer chain glycolipids. Occurrence of antibodies directed at the Gal(beta1-4)Gal epitope was studied by ELISA on 108 human sera. Anti-Gal(beta1-4)Gal antibodies were predominantly IgM, and their distribution was similar to that of anti-Gal(alpha1-3)Gal and anti-Forssman IgMs. It was concluded that anti-Gal(beta1-4)Gal are natural antibodies, not previously identified in man. They can be considered as xenoantibodies directed at species which express Gal(beta1-4)Gal-terminated carbohydrate chains.
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Affiliation(s)
- D Bouhours
- INSERM U.437, Centre Hospitalier Universitaire, Nantes, France
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42
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Warraich RS, Pomerance A, Stanley A, Banner NR, Dunn MJ, Yacoub MH. Cardiac myosin autoantibodies and acute rejection after heart transplantation in patients with dilated cardiomyopathy. Transplantation 2000; 69:1609-17. [PMID: 10836370 DOI: 10.1097/00007890-200004270-00015] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine whether humoral autoimmune responses associated with dilated cardiomyopathy (DCM) influence the postoperative clinical course following cardiac transplantation. METHODS ELISA levels of preformed cardiac myosin (CM) autoantibodies (Abs) in patients with a pretransplant diagnosis of dilated cardiomyopathy (DCM) (n=64) and ischemic heart disease (IHD, n=53) were correlated with cardiac rejection, immunosuppression, and the incidence of endocardial infiltrates after transplantation. RESULTS Alpha- and beta-CM autoantibody (IgG and IgM) levels were similar in DCM and IHD patients but were statistically higher than in controls. Distribution of preformed (beta-CM) IgM-Abs in patients with and without rejection in the first postoperative year differed in the two groups. DCM patients rejected earlier P=0.006, and the frequency of rejection at 3 months was statistically higher than in IHD patients. Frequency and reactivity of IgM-Abs in DCM patients with rejection [International Society for Heart and Lung Transplant (ISHLT) grade I and above] was 28% compared with 7% in rejection-free patients, P<0.05. IgM-positive patients had a greater frequency and severity of rejection episodes and required more immunosuppression. These patients had rejection earlier than Ab-negative patients, P<0.009. There was no correlation between antibody status and rejection in IHD patients or with IgG in either group. Distribution of IgG subclass differed in the two diseases. DCM patients had significantly higher IgG3 reactivity; 70% of this activity was present in patients who developed moderate rejection. IgG3-positive patients experienced more frequent rejections, as well as a greater incidence of grade 3A/B rejection as the first episode, than did Ab-negative patients (50% vs. 15%), P<0.05. Frequency of endocardial infiltrates was statistically higher in IgG3-positive patients. CONCLUSION Proinflammatory characteristics of preformed IgG3 and IgM antibodies in DCM patients may influence the frequency and severity of cardiac rejection after transplantation.
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Affiliation(s)
- R S Warraich
- Department of Cardiothoracic Surgery and Transplant Medicine, National Heart and Lung Institute of Imperial College School of Medicine, Royal Brompton and Harefield Trust, Harefield Hospital, Middlesex, UK
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43
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Kearns-Jonker M, Swensson J, Ghiuzeli C, Chu W, Osame Y, Starnes V, Cramer DV. The Human Antibody Response to Porcine Xenoantigens Is Encoded by IGHV3-11 and IGHV3-74 IgVH Germline Progenitors. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.8.4399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Preformed and induced Ab responses present a major immunological barrier to the use of pig organs for human xenotransplantation. We generated IgM and IgG gene libraries established from lymphocytes of patients treated with a bioartificial liver (BAL) containing pig hepatocytes and used these libraries to identify IgVH genes that encode human Ab responses to pig xenoantigens. Genes encoded by the VH3 family are increased in expression in patients following BAL treatment. cDNA libraries representing the VH3 gene family were generated, and the relative frequency of expression of genes used to encode the Ab response was determined at days 0, 10, and 21. Ig genes derived from the IGHV3-11 and IGHV3-74 germline progenitors increase in frequency post-BAL. The IGHV3-11 gene encodes 12% of VH3 cDNA clones expressed as IgM Abs at day 0 and 32.4–39.0% of cDNA clones encoding IgM Abs in two patients at day 10. IGHV3-11 and IGHV3-74 genes encoding IgM Abs in these patients are expressed without evidence of somatic mutation. By day 21, an isotype switch occurs and IGHV3-11 IgVH progenitors encode IgG Abs that demonstrate somatic mutation. We cloned these genes into a phagemid vector, expressed these clones as single-chain Abs, and demonstrated that the IGHV3-11 gene encodes Abs with the ability to bind to the gal α (1,3) gal epitope. Our results demonstrate that the xenoantibody response in humans is encoded by IgVH genes restricted to IGHV3-11 and IGHV3-74 germline progenitors. IgM Abs are expressed in germline configuration and IgG Abs demonstrate somatic mutations by day 21.
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Affiliation(s)
- Mary Kearns-Jonker
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Joyce Swensson
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Cristina Ghiuzeli
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Wilson Chu
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Yuka Osame
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Vaughn Starnes
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
| | - Donald V. Cramer
- Transplantation Biology Research Laboratory, Department of Cardiothoracic Surgery, University of Southern California School of Medicine, Los Angeles, CA 90033
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44
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Joziasse DH, Oriol R. Xenotransplantation: the importance of the Galalpha1,3Gal epitope in hyperacute vascular rejection. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1455:403-18. [PMID: 10571028 DOI: 10.1016/s0925-4439(99)00056-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The transplantation of organs from other species into humans is considered to be a potential solution to the shortage of human donor organs. Organ transplantation from pig to human, however, results in hyperacute rejection, initiated by the binding of human natural antidonor antibody and complement. The major target antigen of this natural antibody is the terminal disaccharide Galalphal,3Gal, which is synthesized by Galbeta1,4GlcNAc alpha1,3-galactosyltransferase. Here we review our current knowledge of this key enzyme. A better understanding of structure, enzyme properties, and expression pattern of alpha1,3-galactosyltransferase has opened up several novel therapeutic approaches to prevent hyperacute vascular rejection. Cloning, and expression in vitro of the corresponding cDNA, has allowed to develop strategies to induce immune tolerance, and deplete or neutralize the natural xenoreactive antibody. Elucidation of the genomic structure has led to the production of transgenic animals that are lacking alpha1,3-galactosyltransferase activity. A detailed knowledge of the enzyme properties has formed the basis of approaches to modify donor organ glycosylation by intracellular competition. Study of the expression pattern of alpha1,3-galactosyltransferase has helped to understand the mechanism of hyperacute rejection in discordant xenotransplantation, and that of complement-mediated, natural immunity against interspecies transmission of retroviruses.
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Affiliation(s)
- D H Joziasse
- Department of Medical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands.
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Buonomano R, Tinguely C, Rieben R, Mohacsi PJ, Nydegger UE. Quantitation and characterization of anti-Galalpha1-3Gal antibodies in sera of 200 healthy persons. Xenotransplantation 1999; 6:173-80. [PMID: 10503783 DOI: 10.1034/j.1399-3089.1999.00023.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The natural occurrence of complement-activating anti-Galalpha1-3Gal antibodies (anti-Gal) in human serum is considered as a major obstacle to xenotransplantation. In this study we determined anti-Gal in sera of 200 healthy volunteers (100 male, 100 female) of different age groups using an IgG- and IgM-isotype specific ELISA. In addition, we used a direct hemagglutination test involving rabbit erythrocytes (E(R)), which are known for abundant surface expression of the Galalpha1-3Gal antigen. The measured arbitrary ELISA units (U) for anti-Gal ranged from 5 to 204 U (77+/-47; mean +/- 1 SD) for IgM, and from 1 to 162 U(73+/-32) for IgG. Anti-E(R) hemagglutination titers were between 1: 65536 and 1: 64 (mean 1: 703), with 75% of all serum samples being in the range of 1: 8192-1: 512. Specificity of the tests was determined by immunoabsorption of anti-Gal on Sepharose-coupled synthetic Galalpha1-3Gal antigen, which reduced ELISA as well as agglutination titers by 90% or more. Overall, inter-individual differences of both anti-Gal ELISA values and E(R) agglutination titers exceeded age-, gender-, or ABO-type related changes. A tendency was found to higher anti-Gal IgM values in women than in men (P < 0.005 by Student's t-test), whereas the gender-difference for anti-Gal IgG or E(R) titers was not significant. Application of the anti-Gal ELISA as well as the E(R) agglutination assay for pre-transplant screening of potential pig xenograft recipients is discussed.
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Affiliation(s)
- R Buonomano
- Department of Hematology and Regional Red Cross Blood Transfusion Center, Bern, Switzerland
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46
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Auchincloss H. Literature update 1998, part 3. Xenotransplantation 1999; 6:66-71. [PMID: 10355734 DOI: 10.1034/j.1399-3089.1999.00013.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- H Auchincloss
- Transplantation Unit, Surgical Services, Massachusetts General Hospital, Boston 02114, USA
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