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Gómez AC, Horgan C, Yero D, Bravo M, Daura X, O'Driscoll M, Gibert I, O'Sullivan TP. Synthesis and evaluation of aromatic BDSF bioisosteres on biofilm formation and colistin sensitivity in pathogenic bacteria. Eur J Med Chem 2023; 261:115819. [PMID: 37748387 DOI: 10.1016/j.ejmech.2023.115819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023]
Abstract
The diffusible signal factor family (DSF) of molecules play an important role in regulating intercellular communication, or quorum sensing, in several disease-causing bacteria. These messenger molecules, which are comprised of cis-unsaturated fatty acids, are involved in the regulation of biofilm formation, antibiotic tolerance, virulence and the control of bacterial resistance. We have previously demonstrated how olefinic N-acyl sulfonamide bioisosteric analogues of diffusible signal factor can reduce biofilm formation or enhance antibiotic sensitivity in a number of bacterial strains. This work describes the design and synthesis of a second generation of aromatic N-acyl sulfonamide bioisosteres. The impact of these compounds on biofilm production in Acinetobacter baumannii, Escherichia coli, Burkholderia multivorans, Burkholderia cepacia, Burkholderia cenocepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia is evaluated, in addition to their effects on antibiotic tolerance. The ability of these molecules to increase survival rates on co-administration with colistin is also investigated using the Galleria infection model.
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Affiliation(s)
- Andromeda-Celeste Gómez
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Conor Horgan
- School of Chemistry, University College Cork, Cork, Ireland
| | - Daniel Yero
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marc Bravo
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xavier Daura
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain; CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, Cerdanyola de Vallès, Spain
| | - Michelle O'Driscoll
- School of Chemistry, University College Cork, Cork, Ireland; School of Pharmacy, University College Cork, Cork, Ireland; Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Timothy P O'Sullivan
- School of Chemistry, University College Cork, Cork, Ireland; School of Pharmacy, University College Cork, Cork, Ireland; Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland.
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Li P, Asad M, Horgan C, MacCormac O, Shapey J, Vercauteren T. Spatial gradient consistency for unsupervised learning of hyperspectral demosaicking: application to surgical imaging. Int J Comput Assist Radiol Surg 2023:10.1007/s11548-023-02865-7. [PMID: 36961613 DOI: 10.1007/s11548-023-02865-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 03/03/2023] [Indexed: 03/25/2023]
Abstract
PURPOSE Hyperspectral imaging has the potential to improve intraoperative decision making if tissue characterisation is performed in real-time and with high-resolution. Hyperspectral snapshot mosaic sensors offer a promising approach due to their fast acquisition speed and compact size. However, a demosaicking algorithm is required to fully recover the spatial and spectral information of the snapshot images. Most state-of-the-art demosaicking algorithms require ground-truth training data with paired snapshot and high-resolution hyperspectral images, but such imagery pairs with the exact same scene are physically impossible to acquire in intraoperative settings. In this work, we present a fully unsupervised hyperspectral image demosaicking algorithm which only requires exemplar snapshot images for training purposes. METHODS We regard hyperspectral demosaicking as an ill-posed linear inverse problem which we solve using a deep neural network. We take advantage of the spectral correlation occurring in natural scenes to design a novel inter spectral band regularisation term based on spatial gradient consistency. By combining our proposed term with standard regularisation techniques and exploiting a standard data fidelity term, we obtain an unsupervised loss function for training deep neural networks, which allows us to achieve real-time hyperspectral image demosaicking. RESULTS Quantitative results on hyperspetral image datasets show that our unsupervised demosaicking approach can achieve similar performance to its supervised counter-part, and significantly outperform linear demosaicking. A qualitative user study on real snapshot hyperspectral surgical images confirms the results from the quantitative analysis. CONCLUSION Our results suggest that the proposed unsupervised algorithm can achieve promising hyperspectral demosaicking in real-time thus advancing the suitability of the modality for intraoperative use.
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Affiliation(s)
- Peichao Li
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
| | - Muhammad Asad
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Conor Horgan
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Oscar MacCormac
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Neurosurgery, King's College Hospital NHS Foundation Trust, London, UK
| | - Jonathan Shapey
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Department of Neurosurgery, King's College Hospital NHS Foundation Trust, London, UK
| | - Tom Vercauteren
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
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Garcia Peraza Herrera LC, Horgan C, Ourselin S, Ebner M, Vercauteren T. Hyperspectral image segmentation: a preliminary study on the Oral and Dental Spectral Image Database (ODSI-DB). Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization 2023. [DOI: 10.1080/21681163.2022.2160377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
| | - Conor Horgan
- King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
| | | | - Michael Ebner
- King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
| | - Tom Vercauteren
- King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
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Li P, Ebner M, Noonan P, Horgan C, Bahl A, Ourselin S, Shapey J, Vercauteren T. Deep learning approach for hyperspectral image demosaicking, spectral correction and high-resolution RGB reconstruction. Comput Methods Biomech Biomed Eng Imaging Vis 2021; 10:409-417. [PMID: 38013723 PMCID: PMC10461732 DOI: 10.1080/21681163.2021.1997646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 10/05/2023]
Abstract
Hyperspectral imaging is one of the most promising techniques for intraoperative tissue characterisation. Snapshot mosaic cameras, which can capture hyperspectral data in a single exposure, have the potential to make a real-time hyperspectral imaging system for surgical decision-making possible. However, optimal exploitation of the captured data requires solving an ill-posed demosaicking problem and applying additional spectral corrections. In this work, we propose a supervised learning-based image demosaicking algorithm for snapshot hyperspectral images. Due to the lack of publicly available medical images acquired with snapshot mosaic cameras, a synthetic image generation approach is proposed to simulate snapshot images from existing medical image datasets captured by high-resolution, but slow, hyperspectral imaging devices. Image reconstruction is achieved using convolutional neural networks for hyperspectral image super-resolution, followed by spectral correction using a sensor-specific calibration matrix. The results are evaluated both quantitatively and qualitatively, showing clear improvements in image quality compared to a baseline demosaicking method using linear interpolation. Moreover, the fast processing time of 45 ms of our algorithm to obtain super-resolved RGB or oxygenation saturation maps per image for a state-of-the-art snapshot mosaic camera demonstrates the potential for its seamless integration into real-time surgical hyperspectral imaging applications.
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Affiliation(s)
- Peichao Li
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Michael Ebner
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
| | - Philip Noonan
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Conor Horgan
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
| | - Anisha Bahl
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
| | - Sébastien Ourselin
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
| | - Jonathan Shapey
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
- Department of Neurosurgery, King’s College Hospital NHS Foundation Trust, London, UK
| | - Tom Vercauteren
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London, UK
- Hypervision Surgical Ltd, London, UK
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Horgan C, O' Sullivan TP. Recent Developments in the Practical Application of Novel Carboxylic Acid Bioisosteres. Curr Med Chem 2021; 29:2203-2234. [PMID: 34420501 DOI: 10.2174/0929867328666210820112126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/10/2021] [Accepted: 07/23/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND The carboxylic acid is an important functional group which features in the pharmacophore of some 450 drugs. Unfortunately, some carboxylic acid-containing drugs have been withdrawn from market due to unforeseen toxicity issues. Other issues associated with the carboxylate moiety include reduced metabolic stability or limited passive diffusion across biological membranes. Medicinal chemists often turn to bioisosteres to circumvent such obstacles. OBJECTIVE The aim of this review is to provide a summary of the various applications of novel carboxylic acid bioisosteres which have appeared in the literature since 2013. RESULTS We have summarised the most recent developments in carboxylic acid bioisosterism. In particular, we focus on the changes in bioactivity, selectivity or physiochemical properties brought about by these substitutions, as well as the advantages and disadvantages of each isostere. CONCLUSION The topics discussed herein highlight the continued interest in carboxylate bioisosteres. The development of novel carboxylic acid substitutes which display improved pharmacological profiles is testament to the innovation and creativity required to overcome the challenges faced in modern drug design.
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Affiliation(s)
- Conor Horgan
- School of Chemistry, University College Cork, Cork. Ireland
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Abstract
This review summarises the many developments in the synthesis of acyclic peroxides, with a particular focus on the past 20 years, and seeks to update organic chemists about these new approaches.
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Affiliation(s)
- H. Gandhi
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - K. O'Reilly
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - M. K. Gupta
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - C. Horgan
- Department of Chemistry
- University College Cork
- Cork
- Ireland
| | - E. M. O'Leary
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
| | - T. P. O'Sullivan
- Department of Chemistry
- University College Cork
- Cork
- Ireland
- Analytical and Biological Chemistry Research Facility
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Huskamp HA, Garnick DW, Hanson KW, Horgan C. The impact of withdrawals by Medicaid managed care plans on behavioral health services. Psychiatr Serv 2001; 52:600-2. [PMID: 11331792 DOI: 10.1176/appi.ps.52.5.600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- H A Huskamp
- Department of Health Care Policy, Harvard Medical School, 180 Longwood Avenue, Boston, MA 02115, USA.
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Garnick DW, Hendricks AM, Comstock C, Horgan C. Do individuals with substance abuse diagnoses incur higher charges than individuals with other chronic conditions? J Subst Abuse Treat 1997; 14:457-65. [PMID: 9437615 DOI: 10.1016/s0740-5472(97)00137-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Concerns about high costs have led to limits on the services covered by most insurance plans for substance abuse treatment. But, the commonly used comparison group for cost analyses, all enrollees in a health-care plan, may not be appropriate because addiction is a chronic condition. Therefore, to determine whether substance abusers incur higher charges than patients with other serious chronic conditions, we used health insurance information for employees and dependents over 3 years (1989 to 1991) for two firms with a total of almost 40,000 employees to do alternate comparisons. We compared average annual charges for patients with the following diagnoses: substance abuse, substance abuse with mental illness, arthritis, asthma, and diabetes. Patients who undergo treatment for abusing alcohol, drugs, or both often (but not always) incur higher charges than people with other chronic conditions. Clear differences in average charges emerge between patients with and without mental health claims.
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Affiliation(s)
- D W Garnick
- Institute for Health Policy Studies, Heller School for Advanced Studies in Social Welfare, Brandeis University, Waltham, MA 02254-9110, USA
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9
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Ziegel ER, Glasbey C, Horgan C. Image Analysis for the Biological Sciences. Technometrics 1996. [DOI: 10.2307/1270636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Garnick DW, Hendricks AM, Dulski JD, Thorpe KE, Horgan C. Characteristics of private-sector managed care for mental health and substance abuse treatment. Hosp Community Psychiatry 1994; 45:1201-5. [PMID: 7868102 DOI: 10.1176/ps.45.12.1201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE This study examined diversity during the late 1980s in managed care programs for mental health, alcohol abuse, and drug abuse to identify ways in which research can generate more meaningful data on the effectiveness of utilization review programs. METHODS Telephone interviews were conducted with representatives of utilization review programs for employee health insurance plans in 31 firms that employed 2.1 million people in 1990. Questions addressed qualifications of personnel, clinical criteria to authorize care, integration with employee assistance plans, penalties for not complying with utilization review procedures, outpatient review, and carve out of mental health and substance abuse review. RESULTS Large variations in utilization review programs were found. Programs employed a range of review personnel and used a variety of clinical criteria to authorize care. More than two-thirds did not carve out mental health and substance abuse review from medical-surgical review. Some firms' employee assistance plans were integrated with utilization review programs, while others remained unintegrated. Penalties for not following program procedures varied widely, as did review of outpatient services. CONCLUSIONS Because of trends toward even more diversity in utilization review programs in the 1990s, research that identifies the specific features of managed care programs that hold most promise for controlling costs while maintaining quality of care will increasingly be needed.
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Affiliation(s)
- D W Garnick
- Institute for Health Policy, Heller School of Public Policy, Brandeis University, Waltham, MA 02254
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Horgan C, Brown K, Pincus SH. Studies on antigen binding by intact and hinge-deleted chimeric antibodies. The Journal of Immunology 1993. [DOI: 10.4049/jimmunol.150.12.5400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
A matched set of chimeric IgG1 and IgG4 antibodies were used to investigate the role of the IgG hinge in binding to Ag with differing space between the epitopes. Antibodies bearing identical V regions and either IgG1 or IgG4 C regions were engineered with and without hinges. We measured the binding of these antibodies to the peptide CYYYEEEEY and to CYYYEEEEY-BSA conjugates with decreasing numbers of peptides per BSA molecule. We earlier showed that V region differences in antibodies could affect Ag binding patterns in solid-phase but not solution-phase assays; however, both types of assay yielded similar results for the hinge-deleted antibodies. Binding of CYYYEEEEY-BSA by hinge-deleted and intact IgG1 was similar, but intact IgG1 bound free peptide better than did hinge-deleted IgG1. Intact IgG4 antibody bound less well to CYYYEEEEY and CYYYEEEEY-BSA than did IgG1 but, surprisingly, hinge-deleted IgG4 showed better binding than did intact IgG4 and was more like the IgG1 antibodies in binding affinity. Thus, the IgG4 hinge may impart a structural constraint that prevents high affinity binding to Ag. The hinge-deleted IgG4 antibody did not activate C, although it bound Ag similarly to IgG1. This study is the first to address the effect of the IgG hinge on Ag binding by using well defined Ag with different epitope densities. Our results may provide an explanation for the apparent low affinity of IgG4 antibodies.
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Affiliation(s)
- C Horgan
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - K Brown
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - S H Pincus
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
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Horgan C, Brown K, Pincus SH. Studies on antigen binding by intact and hinge-deleted chimeric antibodies. J Immunol 1993; 150:5400-7. [PMID: 7685795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A matched set of chimeric IgG1 and IgG4 antibodies were used to investigate the role of the IgG hinge in binding to Ag with differing space between the epitopes. Antibodies bearing identical V regions and either IgG1 or IgG4 C regions were engineered with and without hinges. We measured the binding of these antibodies to the peptide CYYYEEEEY and to CYYYEEEEY-BSA conjugates with decreasing numbers of peptides per BSA molecule. We earlier showed that V region differences in antibodies could affect Ag binding patterns in solid-phase but not solution-phase assays; however, both types of assay yielded similar results for the hinge-deleted antibodies. Binding of CYYYEEEEY-BSA by hinge-deleted and intact IgG1 was similar, but intact IgG1 bound free peptide better than did hinge-deleted IgG1. Intact IgG4 antibody bound less well to CYYYEEEEY and CYYYEEEEY-BSA than did IgG1 but, surprisingly, hinge-deleted IgG4 showed better binding than did intact IgG4 and was more like the IgG1 antibodies in binding affinity. Thus, the IgG4 hinge may impart a structural constraint that prevents high affinity binding to Ag. The hinge-deleted IgG4 antibody did not activate C, although it bound Ag similarly to IgG1. This study is the first to address the effect of the IgG hinge on Ag binding by using well defined Ag with different epitope densities. Our results may provide an explanation for the apparent low affinity of IgG4 antibodies.
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Affiliation(s)
- C Horgan
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
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Horgan C, Brown K, Pincus SH. Variable region differences affect antibody binding to immobilized but not soluble antigen. Hum Antibodies Hybridomas 1992; 3:153-7. [PMID: 1391665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have examined the antigen binding characteristics of two chimeric IgG1 antibodies that differ only in the heavy chain variable region. Antibodies 10B and B11 were expressed from two different anti-(Tyr,Glu)-Ala-Lys murine VH genes joined to human IgG1 constant region genes in a murine anti-(Tyr,Glu)-Ala-Lys heavy chain loss variant hybridoma. The binding characteristics of the antibodies to (Tyr,Glu)-Ala-Lys and to a peptide conjugate, CYYYEEEEY:BSA, were measured in solution and solid phase assays. The antibodies exhibited similar affinities and binding characteristics when assayed in solution assays. However, when we measured binding of antibodies to immobilized antigens, we found that antibody affinity depended on the epitope density in the immobilized immune complexes. The binding of antibody 10B and of B11 to immobilized (Tyr,Glu)-Ala-Lys and to CYYYEEEEY:BSA were similar at high antigen density, but antibody B11 bound less well at lower antigen density. Fab fragments of 10B bound to immobilized (Tyr,Glu)-Ala-Lys and CYYYEEEEY:BSA, but Fab fragments of B11 did not bind to (Tyr,Glu)-Ala-Lys and bound less well to CYYYEEEEY:BSA than 10B Fabs.
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Affiliation(s)
- C Horgan
- Laboratory of Microbial Structure and Function, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT
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Horgan C, Brown K, Pincus SH. Effect of H chain V region on complement activation by immobilized immune complexes. The Journal of Immunology 1992. [DOI: 10.4049/jimmunol.149.1.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Activation of C by immune complexes (IC) in tissues and the inflammatory consequences are major determinants in the pathogenesis of many autoimmune disorders. To assess the factors involved in C activation by such IC, we examined the binding of C components by chimeric IgG1 antibodies bound to immobilized Ag. We previously reported that alterations in the H chain V regions can affect the binding of first component of C (C1q) and a major breakdown product of the third C component (C3b) when otherwise identical antibodies were bound to immobilized (Tyr, Glu)-Ala-Lys. To evaluate C activation of these antibodies in well defined IC, we utilized a 9-amino acid peptide conjugated to BSA as Ag. The peptide:BSA conjugate was bound similarly by the two IgG1 antibodies which differed mainly in the CDR3 regions, but also in 9 other amino acids in the H chain V region. When soluble IC were prepared with the two antibodies, they activated C similarly. However, C activation by solid phase Ag:antibody complexes differed; we found that antibody 10B bound more C1q and C3b than antibody B11 did, unless the Ag was present at high density on the plates. These data suggest that the variable region differences affect C activation by these antibody when they are bound to immobilized Ag. Furthermore, these results underscore the differences in C activation by the same antibody depending upon whether the IC are free in solution or immobilized.
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Affiliation(s)
- C Horgan
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - K Brown
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
| | - S H Pincus
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
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Horgan C, Brown K, Pincus SH. Effect of H chain V region on complement activation by immobilized immune complexes. J Immunol 1992; 149:127-35. [PMID: 1607649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Activation of C by immune complexes (IC) in tissues and the inflammatory consequences are major determinants in the pathogenesis of many autoimmune disorders. To assess the factors involved in C activation by such IC, we examined the binding of C components by chimeric IgG1 antibodies bound to immobilized Ag. We previously reported that alterations in the H chain V regions can affect the binding of first component of C (C1q) and a major breakdown product of the third C component (C3b) when otherwise identical antibodies were bound to immobilized (Tyr, Glu)-Ala-Lys. To evaluate C activation of these antibodies in well defined IC, we utilized a 9-amino acid peptide conjugated to BSA as Ag. The peptide:BSA conjugate was bound similarly by the two IgG1 antibodies which differed mainly in the CDR3 regions, but also in 9 other amino acids in the H chain V region. When soluble IC were prepared with the two antibodies, they activated C similarly. However, C activation by solid phase Ag:antibody complexes differed; we found that antibody 10B bound more C1q and C3b than antibody B11 did, unless the Ag was present at high density on the plates. These data suggest that the variable region differences affect C activation by these antibody when they are bound to immobilized Ag. Furthermore, these results underscore the differences in C activation by the same antibody depending upon whether the IC are free in solution or immobilized.
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Affiliation(s)
- C Horgan
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840
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Horgan C, Brown K, Pincus SH. Alteration in H chain V region affects complement activation by chimeric antibodies. The Journal of Immunology 1990. [DOI: 10.4049/jimmunol.145.8.2527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Chimeric antibodies to the synthetic polypeptide (Tyr, Glu)-Ala-Lys ((T,G)-A-L) were used to examine C activation by human IgG1. Two IgG1 antibodies, which contained mouse L chains and H chains with mouse V domains and human C domains, differed only in their VH domain. Ag binding and C activation by these antibodies were analyzed by ELISA. When limiting amounts of Ag were used in the assays, the antibodies required different quantities of Ag for optimal binding, suggesting that the antibodies bind to different epitopes on the (T,G)-A-L molecule. However, when competitive inhibition assays were performed with an optimal concentration of Ag, there were no differences in relative binding affinities for (T,G)-A-L or dissociation characteristics of the antibodies. C activation was examined at optimal Ag concentration to ensure equivalent binding of two IgG1 antibodies to Ag. After combination with immobilized Ag, these two antibodies bearing different V regions exhibited marked differences in the binding of C components C1q and C3d. When present in equal amounts in the assay, antibody 10B activated C and bound more C1q and C3d than antibody B11. These results indicate that V region differences can affect C activation by IgG.
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Affiliation(s)
- C Horgan
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, MT 59840
| | - K Brown
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, MT 59840
| | - S H Pincus
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, MT 59840
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Horgan C, Brown K, Pincus SH. Alteration in H chain V region affects complement activation by chimeric antibodies. J Immunol 1990; 145:2527-32. [PMID: 2120333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chimeric antibodies to the synthetic polypeptide (Tyr, Glu)-Ala-Lys ((T,G)-A-L) were used to examine C activation by human IgG1. Two IgG1 antibodies, which contained mouse L chains and H chains with mouse V domains and human C domains, differed only in their VH domain. Ag binding and C activation by these antibodies were analyzed by ELISA. When limiting amounts of Ag were used in the assays, the antibodies required different quantities of Ag for optimal binding, suggesting that the antibodies bind to different epitopes on the (T,G)-A-L molecule. However, when competitive inhibition assays were performed with an optimal concentration of Ag, there were no differences in relative binding affinities for (T,G)-A-L or dissociation characteristics of the antibodies. C activation was examined at optimal Ag concentration to ensure equivalent binding of two IgG1 antibodies to Ag. After combination with immobilized Ag, these two antibodies bearing different V regions exhibited marked differences in the binding of C components C1q and C3d. When present in equal amounts in the assay, antibody 10B activated C and bound more C1q and C3d than antibody B11. These results indicate that V region differences can affect C activation by IgG.
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Affiliation(s)
- C Horgan
- National Institutes of Health, National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, Hamilton, MT 59840
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Affiliation(s)
- C Horgan
- Bigel Institute for Health Policy, Heller Graduate School, Brandeis University
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Abstract
In vivo binding of double-stranded DNA (dsDNA) to renal glomeruli of rats was examined. 125I-dsDNA (600 basepairs) was perfused with 131I-IgG as a blood marker into the right renal artery of normal rats, and blood flow was restored. After 10 minutes, isolated glomeruli showed a specific uptake of DNA, which increased in a saturable fashion with increasing doses of administered DNA. To exclude the possibility that 125I in the glomeruli represented only DNA breakdown products, we extracted the DNA from the glomeruli for analysis by polyacrylamide gel electrophoresis. The extracted DNA was 120-200 bp in size, which is large enough to bind antibodies to DNA. In contrast, the radioactivity of DNA taken up by the liver or renal tissues other than glomeruli was predominantly trichloroacetic acid soluble, i.e., less than 15 bp. Immunofluorescence studies showed that antibodies to DNA, administered after DNA, were present in glomeruli. Our data indicate that dsDNA binds to glomeruli in vivo in a saturable manner, and remains large enough to be antigenic. Therefore, the binding of DNA to glomeruli, followed by interaction with antibodies to dsDNA may be a mechanism for DNA-anti-DNA complex formation in glomeruli in patients with systemic lupus erythematosus.
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Affiliation(s)
- C Horgan
- Department of Medicine, University of Washington, Seattle
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Jencks SF, Horgan C, Goldman HH, Taube CA. Bringing excluded psychiatric facilities under the Medicare Prospective Payment System. A review of research evidence and policy options. Med Care 1987; 25:S1-51. [PMID: 3121958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- S F Jencks
- Office of Research, Health Care Financing Administration, Baltimore, MD 21207
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Abstract
125I-ds DNA-anti-DNA immune complexes (IC) formed at antibody excess and containing DNA of 300-350 base pairs (bp) fixed complement, incorporated C3b and bound to the C3b receptors (CR1) on human red blood cells (RBC). When the IC were treated with DNase to generate small, DNase-resistant IC, some of the IC incorporated C3b, but did not bind to RBC. In order to examine C3b incorporation and RBC binding by IC of specific sizes, the DNase treated IC were fractionated by sucrose density gradient (SDG) ultracentrifugation. Small IC containing one, two, three or four IgG molecules per fragment of 125I-ds DNA were identified by autoradiography after electrophoresis of the SDG fractions on 3-12% linear polyacrylamide gradient gels. The SDG fractions were tested for C3b incorporation and RBC binding ability. There was neither C3b incorporation nor RBC binding activity in fractions which corresponded to 9-11S (containing IC with one IgG/DNA). Fractions which corresponded to 12-22S (containing IC with up to four IgG/DNA fragment) demonstrated increased C3b incorporation with increased size, but did not show significant RBC binding activity. Fractions with IC containing four or more IgGs (22-24S) incorporated C3b and bound to RBC at approximately the same level. It is concluded that DNase digested IC which contain three-four IgG/DNA fragment are large enough to activate complement and incorporate C3b, but are too small to bind to RBC CR1. These IC could therefore escape rapid clearance from the circulation via the erythrocyte CR1 clearance mechanism. Such IC could persist in the circulation and potentially elicit pathogenic effects in patients with systemic lupus erythematosus.
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Horgan C, Salkever D. The demand for outpatient mental health care from nonspecialty providers. Adv Health Econ Health Serv Res 1986; 8:211-33. [PMID: 10312958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Broggini M, Erba E, Morasca L, Horgan C, D'Incalci M. In vivo studies with the novel anticancer agent mitozolomide (NSC 353451) on Lewis lung carcinoma. Cancer Chemother Pharmacol 1986; 16:125-8. [PMID: 3948297 DOI: 10.1007/bf00256161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mitozolomide is one of the most effective drugs against Lewis lung carcinoma in the mouse. Two IP doses of 40 mg/kg (days 6 and 15 after IM transplantation of 3LL) or four doses of 20 mg/kg given at various intervals (starting from day 6) increased survival time by 100%. A single IP dose of 80 mg/kg was toxic, and 10 mg/kg was ineffective even when this dose was given on eight occasions. The pharmacokinetics of mitozolomide was investigated in 3LL-bearing mice by HPLC assay. Peak drug levels were achieved in tumor 15 min after IP treatment, after which they declined according to first-order kinetics, with a half-life of 80-100 min (the same as in plasma). No dose-dependent kinetics was observed. Flow cytometry studies showed an accumulation of 3LL cells in G2M 24 h after drug treatment. This cell cycle perturbation was reversed 96 h after the inactive dose of 10 mg/kg, but not after the effective dose of 40 mg/kg.
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Taylor RP, Horgan C, Hooper M, Burge J. Dynamics of interaction between complement-fixing antibody/dsDNA immune complexes and erythrocytes. In vitro studies and potential general applications to clinical immune complex testing. J Clin Invest 1985; 75:102-11. [PMID: 3917462 PMCID: PMC423414 DOI: 10.1172/jci111660] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Soluble antibody/3H-double-stranded PM2 DNA (dsDNA) immune complexes were briefly opsonized with complement and then allowed to bind to human erythrocytes (via complement receptors). The cells were washed and subsequently a volume of autologous blood in a variety of media was added, and the release of the bound immune complexes from the erythrocytes was studied as a function of temperature and time. After 1-2 h, the majority of the bound immune complexes were not released into the serum during blood clotting at either 37 degrees C or room temperature, but there was a considerably greater release of the immune complexes into the plasma of blood that was anticoagulated with EDTA. Similar results were obtained using various conditions of opsonization and also using complexes that contained lower molecular weight dsDNA. Thus, the kinetics of release of these antibody/dsDNA immune complexes differed substantially from the kinetics of release of antibody/bovine serum albumin complexes that was reported by others. Studies using the solution phase C1q immune complex binding assay confirmed that in approximately half of the SLE samples that were positive for immune complexes, there was a significantly higher level of detectable immune complexes in plasma vs. serum. Freshly drawn erythrocytes from some SLE patients exhibiting this plasma/serum discrepancy had IgG antigen on their surface that was released by incubation in EDTA plasma. Thus, the higher levels of immune complexes observed in EDTA plasma vs. serum using the C1q assay may often reflect the existence of immune complexes circulating in vivo bound to erythrocytes.
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Horgan C, Taylor RP. Complement-component-C3-opsonized immunoglobulin G anti-DNA antibodies do not bind effectively to red blood cells unless aggregated on a high-Mr DNA matrix. Biochem J 1984; 224:755-9. [PMID: 6525175 PMCID: PMC1144510 DOI: 10.1042/bj2240755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Large, soluble ds (double-stranded) DNA-IgG (immunoglobulin G) anti-dsDNA immune complexes (greater than or equal to 200 S) that were previously opsonized with complement were digested with DNAase. The small complement-component-C3-fragment-labelled IgG (11-14 S) that was then isolated did not bind effectively to complement receptor type 1 on human red blood cells. However, when this IgG was immune-complexed with 3H-labelled PM2 (bacteriophage directed against a marine Pseudomonas) dsDNA (Mr approximately 6 X 10(6), substantial binding of both the DNA antigen and IgG to the erythrocytes was demonstrable.
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Taylor RP, Horgan C, Harbin A, Burge J. Suramin inhibits the binding of complement-fixing antibody/double-stranded DNA immune complexes to CR1. Clin Immunol Immunopathol 1984; 33:220-31. [PMID: 6488590 DOI: 10.1016/0090-1229(84)90077-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The effects of varying concentrations of heparin and suramin on the complement-mediated binding of antibody/double-stranded DNA immune complexes to red blood cells (RBCs) and Raji cells have been investigated. If the immune complexes are briefly opsonized with complement, suramin can block binding to both cell types, and heparin can block binding to RBCs. In addition, if these complexes are first allowed to bind to RBCs or Raji cells, relatively brief incubations in suramin are sufficient to cause release of the complexes from the cells' C3b receptors. The potential clinical and diagnostic implications of these findings are discussed.
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Horgan C, Burge J, Crawford L, Taylor RP. The kinetics of [3H]-dsDNA/anti-DNA immune complex formation, binding by red blood cells, and release into serum: effect of DNA molecular weight and conditions of antibody excess. The Journal of Immunology 1984. [DOI: 10.4049/jimmunol.133.4.2079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
[3H]dsDNA/anti-DNA immune complexes (IC) formed, fixed complement, and bound rapidly to red blood cells (RBC) in whole blood (less than 5 min), but were released from the cells more slowly. The rate of release was dependent on both the antibody:DNA ratio and the m.w. of the DNA in the complex. For example, complexes formed with high m.w. DNA (6 X 10(6) daltons) were released more slowly (t1/2 = 60 min) than complexes formed with lower m.w. DNA (2 to 6 X 10(5) daltons, t1/2 = 15 to 20 min). The [3H]dsDNA/anti-DNA complexes, which were released from the cells as intact antigen/antibody/complement complexes, did not rebind to RBC, but did bind to Raji cells and could be precipitated by monoclonal antibody to C3d. When these released IC (RIC) containing high m.w. DNA were incubated with additional anti-DNA antibody and fresh complement, they rebound to RBC. However, RIC containing lower m.w. DNA (5 X 10(5) daltons) did not rebind to RBC under the same conditions. These data suggest that IC containing high m.w. DNA bind to and remain bound to RBC more effectively than IC containing lower m.w. DNA, and thus may be more easily cleared from the circulation by the RBC IC clearance mechanism. Thus, the size of the DNA in the IC may be a significant factor in the pathogenicity of DNA/anti-DNA complexes in SLE.
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Horgan C, Burge J, Crawford L, Taylor RP. The kinetics of [3H]-dsDNA/anti-DNA immune complex formation, binding by red blood cells, and release into serum: effect of DNA molecular weight and conditions of antibody excess. J Immunol 1984; 133:2079-84. [PMID: 6332147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
[3H]dsDNA/anti-DNA immune complexes (IC) formed, fixed complement, and bound rapidly to red blood cells (RBC) in whole blood (less than 5 min), but were released from the cells more slowly. The rate of release was dependent on both the antibody:DNA ratio and the m.w. of the DNA in the complex. For example, complexes formed with high m.w. DNA (6 X 10(6) daltons) were released more slowly (t1/2 = 60 min) than complexes formed with lower m.w. DNA (2 to 6 X 10(5) daltons, t1/2 = 15 to 20 min). The [3H]dsDNA/anti-DNA complexes, which were released from the cells as intact antigen/antibody/complement complexes, did not rebind to RBC, but did bind to Raji cells and could be precipitated by monoclonal antibody to C3d. When these released IC (RIC) containing high m.w. DNA were incubated with additional anti-DNA antibody and fresh complement, they rebound to RBC. However, RIC containing lower m.w. DNA (5 X 10(5) daltons) did not rebind to RBC under the same conditions. These data suggest that IC containing high m.w. DNA bind to and remain bound to RBC more effectively than IC containing lower m.w. DNA, and thus may be more easily cleared from the circulation by the RBC IC clearance mechanism. Thus, the size of the DNA in the IC may be a significant factor in the pathogenicity of DNA/anti-DNA complexes in SLE.
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Taylor RP, Horgan C. Quantitative determination of anti-dsDNA antibodies and antibody/dsDNA stoichiometries in prepared, soluble complement-fixing antibody/dsDNA immune complexes. Mol Immunol 1984; 21:853-62. [PMID: 6334233 DOI: 10.1016/0161-5890(84)90139-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have investigated quantitatively the complement-mediated binding of prepared, soluble 125I-7S IgG antibody/3H-dsDNA immune complexes to human red blood cells (RBCs). We have performed these studies by using a detailed modification of the RBC-CF assay [Pedersen et al., J. Immun. Meth. 38, 269-280 (1980)] which now allows for the simultaneous measurement of both 3H-DNA and 125I-binding to the cells. Our results indicate that, in the case of three SLE patients, their anti-dsDNA antibody titers are sufficiently high that a small fraction of their 125I-7S IgG antibodies (ca 0.1-0.2%) can be identified as specifically anti-dsDNA. We have also used an indirect method (with 125I-labelled rabbit anti-human IgG) for the determination of IgG anti-dsDNA antibodies in complement-fixing antibody/dsDNA immune complexes that bind to RBCs, and the results of these measurements are in reasonable agreement with the direct binding experiments. These studies have also allowed us to estimate the antibody/DNA stoichiometries in complement-fixing immune complexes. The results of these experiments may provide a useful standard for the analysis of monoclonal anti-dsDNA antibodies.
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Horgan C, Taylor RP. Quantitative analyses of complement fixation in three immune complex systems. Immunology 1984; 52:753-9. [PMID: 6611301 PMCID: PMC1454649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The quantitative interaction of three different immune complex systems with complement has been investigated. dsDNA/anti-DNA, heat-aggregated IgG subfractions, and human IgG/rabbit anti-human IgG complexes were tested for their ability to consume complement (immune haemolysis assay) and to bind to red blood cells in a complement-mediated reaction (the RBC-CF assay). Our results indicate that some physical and immunological properties of the dsDNA/anti-DNA immune complex systems are significantly different from those of immune complexes that involve more common globular protein antigens. This difference in properties may help explain the role of dsDNA/anti-DNA immune complexes in systemic lupus erythematosus pathogenesis.
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Horgan C, Taylor RP. Studies on the kinetics of binding of complement-fixing dsdna/anti-dsdna immune complexes to the red blood cells of normal individuals and patients with systemic lupus erythematosus. ACTA ACUST UNITED AC 1984; 27:320-9. [PMID: 6546694 DOI: 10.1002/art.1780270312] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The kinetics of binding of prepared complement opsonized 3H-dsDNA/anti-DNA immune complexes to normal red blood cells (RBCs) and to RBCs with lowered immune complex binding capacity from certain patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis was examined. Normal RBCs bound the immune complexes rapidly and reached equilibrium in about 4 minutes at 37 degrees C, while the SLE RBCs not only bound less immune complex but required up to 30 minutes to reach equilibrium. Chemical modification of normal RBCs with moderate amounts of dithiothreitol, an agent that destroys the binding activity of the C3b receptor (CR1), produced RBCs that mimicked the equilibrium and kinetic binding properties of the SLE RBCs. These observations, taken in conjunction with a detailed examination of the temperature dependence of the binding kinetics, suggest that CR1 reorganization on the RBC surface to form binding clusters may be an essential step in the complement mediated binding of immune complexes to RBCs. The implications of these findings with respect to the clearance of immune complexes from the circulation of patients with autoimmune diseases are discussed.
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Merani MS, Vercellini O, Acuña AM, Horgan C, Roldan ER. Growth and reproduction of two species of Akodon and their hybrids. J Exp Zool 1983; 228:527-35. [PMID: 6363612 DOI: 10.1002/jez.1402280312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Growth and reproduction of Akodon molinae (A.m.), A. dolores (A.d.) (Rodentia: Cricetidae), and their hybrids are described. A.d. showed less fertility under animal room conditions, fewer "successful" matings, similar litter sizes, and an altered sex proportion as compared to A.m.; A.d. ovulatory index is supposed to be higher than mean litter size. X-linked lethal gene(s) and chromosome polymorphisms are possible causes of these variations. Interspecific crosses showed a marked seasonal (summer) tendency in parturitions. Intraspecific matings also produced young during winter. F1 hybrids showed a reversed tendency, while F2 matings returned to the parental pattern. A.d. male X A.m. female and F1 crosses presented larger litter sizes than the other pairings. A.m. exhibited sexual differences in weight after 60 days of age. A.d. and F1 hybrids did not show significant differences in weight of both sexes at any age. A.m. males and females were heavier than A.d. individuals except 12 months after birth. F1 hybrids born to A.m. male were heavier at birth than the A.d. female s interspecific offspring, and may be interpreted as a maternal influence of the A.m. females. Hybrids were heavier than their parents at birth and some of them were also heavier at 21 days, and probably is due to pseudoheterosis. The comparison of body measurements between sexes of both species did not give conclusive results. A.m. females were larger than females of A.d. Males of both species showed similar total lengths; A.m. males had larger body lengths and shorter tails. Body measurements were not related to weight variations. However, differences in weight and measurements between sexes appeared simultaneously at 2-6 months. This probably reflected the attainment of maturity.
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Taylor RP, Burge J, Horgan C, Shasby DM. The complement-mediated binding of soluble antibody/dsDNA immune complexes to human neutrophils. J Immunol 1983; 130:2656-62. [PMID: 6854016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The complement-mediated binding of soluble antibody/3H-dsDNA immune complexes (prepared in vitro) to human polymorphonuclear leukocytes (PMN) has been investigated quantitatively. Studies with isolated complement components in conjunction with experiments on the binding of these complexes to human red blood cells suggest that the binding to both cell types is mediated predominantly by CR1 (C4b-C3b) receptors but that CR3 (iC3b or C3d-g) receptors may play a role in binding to PMN but probably not to RBC. Our results also indicate that under the standard conditions of these assays (37 degrees C, 20 to 40 min incubations) there is no significant internalization of the soluble antibody/dsDNA immune complexes after they are bound by the PMN.
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Taylor RP, Horgan C, Buschbacher R, Brunner CM, Hess CE, O'Brien WM, Wanebo HJ. Decreased complement mediated binding of antibody/3H-dsDNA immune complexes to the red blood cells of patients with systemic lupus erythematosus, rheumatoid arthritis, and hematologic malignancies. Arthritis Rheum 1983; 26:736-44. [PMID: 6860375 DOI: 10.1002/art.1780260606] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The complement mediated binding of prepared antibody/3H-dsDNA immune complexes to the red blood cells obtained from a number of patient populations has been investigated. Patients with solid tumors have binding activity similar to that seen in a normal group of individuals. However, a significant fraction of patients with systemic lupus erythematosus, rheumatoid arthritis, and hematologic malignancies have lowered binding activity compared with normal subjects. Quantitative studies indicate the lowered activity probably arises due to a decrease in complement receptors on the respective red blood cells. The potential importance and implications of these findings are briefly discussed.
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Taylor RP, Burge J, Horgan C, Shasby DM. The complement-mediated binding of soluble antibody/dsDNA immune complexes to human neutrophils. The Journal of Immunology 1983. [DOI: 10.4049/jimmunol.130.6.2656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The complement-mediated binding of soluble antibody/3H-dsDNA immune complexes (prepared in vitro) to human polymorphonuclear leukocytes (PMN) has been investigated quantitatively. Studies with isolated complement components in conjunction with experiments on the binding of these complexes to human red blood cells suggest that the binding to both cell types is mediated predominantly by CR1 (C4b-C3b) receptors but that CR3 (iC3b or C3d-g) receptors may play a role in binding to PMN but probably not to RBC. Our results also indicate that under the standard conditions of these assays (37 degrees C, 20 to 40 min incubations) there is no significant internalization of the soluble antibody/dsDNA immune complexes after they are bound by the PMN.
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