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ImmunoPET Directed to the Brain: A New Tool for Preclinical and Clinical Neuroscience. Biomolecules 2023; 13:biom13010164. [PMID: 36671549 PMCID: PMC9855881 DOI: 10.3390/biom13010164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/14/2023] Open
Abstract
Immuno-positron emission tomography (immunoPET) is a non-invasive in vivo imaging method based on tracking and quantifying radiolabeled monoclonal antibodies (mAbs) and other related molecules, such as antibody fragments, nanobodies, or affibodies. However, the success of immunoPET in neuroimaging is limited because intact antibodies cannot penetrate the blood-brain barrier (BBB). In neuro-oncology, immunoPET has been successfully applied to brain tumors because of the compromised BBB. Different strategies, such as changes in antibody properties, use of physiological mechanisms in the BBB, or induced changes to BBB permeability, have been developed to deliver antibodies to the brain. These approaches have recently started to be applied in preclinical central nervous system PET studies. Therefore, immunoPET could be a new approach for developing more specific PET probes directed to different brain targets.
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2
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Viola KL, Bicca MA, Bebenek AM, Kranz DL, Nandwana V, Waters EA, Haney CR, Lee M, Gupta A, Brahmbhatt Z, Huang W, Chang TT, Peck A, Valdez C, Dravid VP, Klein WL. The Therapeutic and Diagnostic Potential of Amyloid β Oligomers Selective Antibodies to Treat Alzheimer's Disease. Front Neurosci 2022; 15:768646. [PMID: 35046767 PMCID: PMC8761808 DOI: 10.3389/fnins.2021.768646] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/09/2021] [Indexed: 01/10/2023] Open
Abstract
Improvements have been made in the diagnosis of Alzheimer’s disease (AD), manifesting mostly in the development of in vivo imaging methods that allow for the detection of pathological changes in AD by magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Many of these imaging methods, however, use agents that probe amyloid fibrils and plaques–species that do not correlate well with disease progression and are not present at the earliest stages of the disease. Amyloid β oligomers (AβOs), rather, are now widely accepted as the Aβ species most germane to AD onset and progression. Here we report evidence further supporting the role of AβOs as pathological instigators of AD and introduce promising anti-AβO diagnostic probes capable of distinguishing the 5xFAD mouse model from wild type mice by PET and MRI. In a developmental study, Aβ oligomers in 5xFAD mice were found to appear at 3 months of age, just prior to the onset of memory dysfunction, and spread as memory worsened. The increase of AβOs is prominent in the subiculum and correlates with concomitant development of reactive astrocytosis. The impact of these AβOs on memory is in harmony with findings that intraventricular injection of synthetic AβOs into wild type mice induced hippocampal dependent memory dysfunction within 24 h. Compelling support for the conclusion that endogenous AβOs cause memory loss was found in experiments showing that intranasal inoculation of AβO-selective antibodies into 5xFAD mice completely restored memory function, measured 30–40 days post-inoculation. These antibodies, which were modified to give MRI and PET imaging probes, were able to distinguish 5xFAD mice from wild type littermates. These results provide strong support for the role of AβOs in instigating memory loss and salient AD neuropathology, and they demonstrate that AβO selective antibodies have potential both for therapeutics and for diagnostics.
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Affiliation(s)
- Kirsten L Viola
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Maira A Bicca
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Adrian M Bebenek
- Illinois Mathematics and Science Academy, Aurora, IL, United States
| | - Daniel L Kranz
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Vikas Nandwana
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, United States
| | - Emily A Waters
- Center for Advanced Molecular Imaging, Northwestern University, Evanston, IL, United States
| | - Chad R Haney
- Center for Advanced Molecular Imaging, Northwestern University, Evanston, IL, United States
| | - Maxwell Lee
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Abhay Gupta
- Illinois Mathematics and Science Academy, Aurora, IL, United States
| | | | - Weijian Huang
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Ting-Tung Chang
- Small Animal Imaging Facility, Van Andel Research Institute, Grand Rapids, MI, United States.,Laboratory of Translational Imaging, Van Andel Research Institute, Grand Rapids, MI, United States
| | - Anderson Peck
- Small Animal Imaging Facility, Van Andel Research Institute, Grand Rapids, MI, United States.,Laboratory of Translational Imaging, Van Andel Research Institute, Grand Rapids, MI, United States
| | - Clarissa Valdez
- Department of Neurobiology, Northwestern University, Evanston, IL, United States
| | - Vinayak P Dravid
- Illinois Mathematics and Science Academy, Aurora, IL, United States
| | - William L Klein
- Department of Neurobiology, Northwestern University, Evanston, IL, United States.,Department of Neurology, Northwestern University, Chicago, IL, United States
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3
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Shaw RC, Tamagnan GD, Tavares AAS. Rapidly (and Successfully) Translating Novel Brain Radiotracers From Animal Research Into Clinical Use. Front Neurosci 2020; 14:871. [PMID: 33117115 PMCID: PMC7559529 DOI: 10.3389/fnins.2020.00871] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 07/27/2020] [Indexed: 12/26/2022] Open
Abstract
The advent of preclinical research scanners for in vivo imaging of small animals has added confidence into the multi-step decision-making process of radiotracer discovery and development. Furthermore, it has expanded the utility of imaging techniques available to dissect clinical questions, fostering a cyclic interaction between the clinical and the preclinical worlds. Significant efforts from medicinal chemistry have also made available several high-affinity and selective compounds amenable for radiolabeling, that target different receptors, transporters and enzymes in vivo. This substantially increased the range of applications of molecular imaging using positron emission tomography (PET) or single photon emission computed tomography (SPECT). However, the process of developing novel radiotracers for in vivo imaging of the human brain is a multi-step process that has several inherent pitfalls and technical difficulties, which often hampers the successful translation of novel imaging agents from preclinical research into clinical use. In this paper, the process of radiotracer development and its relevance in brain research is discussed; as well as, its pitfalls, technical challenges and future promises. Examples of successful and unsuccessful translation of brain radiotracers will be presented.
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Affiliation(s)
- Robert C. Shaw
- BHF Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Adriana Alexandre S. Tavares
- BHF Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
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4
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Focused ultrasound for opening blood-brain barrier and drug delivery monitored with positron emission tomography. J Control Release 2020; 324:303-316. [DOI: 10.1016/j.jconrel.2020.05.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022]
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5
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Engineered antibodies: new possibilities for brain PET? Eur J Nucl Med Mol Imaging 2019; 46:2848-2858. [PMID: 31342134 PMCID: PMC6879437 DOI: 10.1007/s00259-019-04426-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/03/2019] [Indexed: 12/18/2022]
Abstract
Almost 50 million people worldwide are affected by Alzheimer’s disease (AD), the most common neurodegenerative disorder. Development of disease-modifying therapies would benefit from reliable, non-invasive positron emission tomography (PET) biomarkers for early diagnosis, monitoring of disease progression, and assessment of therapeutic effects. Traditionally, PET ligands have been based on small molecules that, with the right properties, can penetrate the blood–brain barrier (BBB) and visualize targets in the brain. Recently a new class of PET ligands based on antibodies have emerged, mainly in applications related to cancer. While antibodies have advantages such as high specificity and affinity, their passage across the BBB is limited. Thus, to be used as brain PET ligands, antibodies need to be modified for active transport into the brain. Here, we review the development of radioligands based on antibodies for visualization of intrabrain targets. We focus on antibodies modified into a bispecific format, with the capacity to undergo transferrin receptor 1 (TfR1)-mediated transcytosis to enter the brain and access pathological proteins, e.g. amyloid-beta. A number of such antibody ligands have been developed, displaying differences in brain uptake, pharmacokinetics, and ability to bind and visualize the target in the brain of transgenic mice. Potential pathological changes related to neurodegeneration, e.g. misfolded proteins and neuroinflammation, are suggested as future targets for this novel type of radioligand. Challenges are also discussed, such as the temporal match of radionuclide half-life with the ligand’s pharmacokinetic profile and translation to human use. In conclusion, brain PET imaging using bispecific antibodies, modified for receptor-mediated transcytosis across the BBB, is a promising method for specifically visualizing molecules in the brain that are difficult to target with traditional small molecule ligands.
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6
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Sun D, Qiao Y, Jiang X, Li P, Kuai Z, Gong X, Liu D, Fu Q, Sun L, Li H, Ding J, Shi Y, Kong W, Shan Y. Multiple Antigenic Peptide System Coupled with Amyloid Beta Protein Epitopes As An Immunization Approach to Treat Alzheimer's Disease. ACS Chem Neurosci 2019; 10:2794-2800. [PMID: 31042358 DOI: 10.1021/acschemneuro.9b00020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Latest studies suggest that Alzheimer's disease (AD) is one of the "four big killers" that threaten the health of the elderly. AD affects about 46 million people across the world, and there is a critical need for research on new therapies for treating AD. The purpose of the present study was to develop and evaluate immunogens to elicit antibodies against the formation of amyloid beta protein (Aβ), a pathological hallmark of AD, as a therapeutic strategy in AD. In this study, serial potential immunogenic epitopes were screened according to the Aβ sequence. The screened linear epitopes on the Aβ C-terminal fragment were coupled with either the carrier protein keyhole limpet hemocyanin (KLH) or the synthesized 4-branch peptide (MAP4). MAP4 immunogens could effectively elicit immunogenicity against Aβ1-42 monomer and fiber in Balb/C mice. Furthermore, MAP4 sera could also effectively inhibit the formation of the Aβ1-42 fiber. Interestingly, one of the MAP4 sera was able to depolymerize the Aβ1-42 fibers that had aggregated. The monoclonal antibody, 1H7, was shown to inhibit the formation of Aβ1-42 fiber. MAP4 carrier may provide benefits over current immunization strategies, as it does not induce inflammation. In conclusion, the MAP4-Aβ conjugates offer a promising approach for the development of a safe and effective AD vaccine.
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Affiliation(s)
- Diya Sun
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Yongbo Qiao
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Xiaoyu Jiang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Pengju Li
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Ziyu Kuai
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Xin Gong
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Dongni Liu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Qiang Fu
- Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, China
| | - Liyan Sun
- Dalian University Affiliated Xinhua Hospital, Dalian, Liaoning 116021, China
| | - He Li
- Affiliated Dalian Friendship Hospital of Dalian Medical University, Dalian, Liaoning 116100, China
| | - Jun Ding
- China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, China
| | - Yuhua Shi
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Wei Kong
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
| | - Yaming Shan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin 130012, China
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7
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Chen K, Cui M. Recent progress in the development of metal complexes as β-amyloid imaging probes in the brain. MEDCHEMCOMM 2017; 8:1393-1407. [PMID: 30108850 PMCID: PMC6072098 DOI: 10.1039/c7md00064b] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 05/11/2017] [Indexed: 01/28/2023]
Abstract
In this review, we have focused on the recent progress in metal complexes that are able to bind to β-amyloid (Aβ) species. We have discussed various radioactive complexes of 99mTc, 68Ga, 64Cu, 89Zr, and 111In, which were designed as Aβ imaging agents for positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging, non-radioactive Re and Ru complexes as Aβ sensors using luminescence methods, and Gd3+ complexes as contrast agents for magnetic resonance imaging (MRI).
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Affiliation(s)
- Kaihua Chen
- Key Laboratory of Radiopharmaceuticals , Ministry of Education , College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China . ; ; Tel: +86 10 58808891
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals , Ministry of Education , College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China . ; ; Tel: +86 10 58808891
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8
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Waldron AM, Fissers J, Van Eetveldt A, Van Broeck B, Mercken M, Pemberton DJ, Van Der Veken P, Augustyns K, Joossens J, Stroobants S, Dedeurwaerdere S, Wyffels L, Staelens S. In Vivo Amyloid-β Imaging in the APPPS1-21 Transgenic Mouse Model with a (89)Zr-Labeled Monoclonal Antibody. Front Aging Neurosci 2016; 8:67. [PMID: 27064204 PMCID: PMC4815004 DOI: 10.3389/fnagi.2016.00067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/21/2016] [Indexed: 11/30/2022] Open
Abstract
Introduction: The accumulation of amyloid-β is a pathological hallmark of Alzheimer’s disease and is a target for molecular imaging probes to aid in diagnosis and disease monitoring. This study evaluated the feasibility of using a radiolabeled monoclonal anti-amyloid-β antibody (JRF/AβN/25) to non-invasively assess amyloid-β burden in aged transgenic mice (APPPS1–21) with μPET imaging. Methods: We investigated the antibody JRF/AβN/25 that binds to full-length Aβ. JRF/AβN/25 was radiolabeled with a [89Zr]-desferal chelate and intravenously injected into 12–13 month aged APPPS1–21 mice and their wild-type (WT) controls. Mice underwent in vivo μPET imaging at 2, 4, and 7 days post injection and were sacrificed at the end of each time point to assess brain penetrance, plaque labeling, biodistribution, and tracer stability. To confirm imaging specificity we also evaluated brain uptake of a non-amyloid targeting [89Zr]-labeled antibody (trastuzumab) as a negative control, additionally we performed a competitive blocking study with non-radiolabeled Df-Bz-JRF/AβN/25 and finally we assessed the possible confounding effects of blood retention. Results: Voxel-wise analysis of μPET data demonstrated significant [89Zr]-Df-Bz-JRF/AβN/25 retention in APPPS1–21 mice at all time points investigated. With ex vivo measures of radioactivity, significantly higher retention of [89Zr]-Df-Bz-JRF/AβN/25 was found at 4 and 7 days pi in APPPS1–21 mice. Despite the observed genotypic differences, comparisons with immunohistochemistry revealed that in vivo plaque labeling was low. Furthermore, pre-treatment with Df-Bz-JRF/AβN/25 only partially blocked [89Zr]-Df-Bz-JRF/AβN/25 uptake indicative of a high contribution of non-specific binding. Conclusion: Amyloid plaques were detected in vivo with a radiolabeled monoclonal anti-amyloid antibody. The low brain penetrance of the antibody in addition to non-specific binding prevented an accurate estimation of plaque burden. However, it should be noted that [89Zr]-Df-Bz-JRF/AβN/25 nevertheless demonstrated in vivo binding and strategies to increase brain penetrance would likely achieve better results.
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Affiliation(s)
- Ann-Marie Waldron
- Faculty of Medicine and Health Sciences, Molecular Imaging Center Antwerp, University of AntwerpAntwerp, Belgium; Translational Neurosciences, University of AntwerpAntwerp, Belgium
| | - Jens Fissers
- Faculty of Medicine and Health Sciences, Molecular Imaging Center Antwerp, University of AntwerpAntwerp, Belgium; Laboratory of Medicinal Chemistry, University of AntwerpAntwerp, Belgium
| | | | - Bianca Van Broeck
- Department of Neuroscience, Janssen Research and Development, A Division of Janssen Pharmaceutica NV Beerse, Belgium
| | - Marc Mercken
- Department of Neuroscience, Janssen Research and Development, A Division of Janssen Pharmaceutica NV Beerse, Belgium
| | - Darrel J Pemberton
- Department of Neuroscience, Janssen Research and Development, A Division of Janssen Pharmaceutica NV Beerse, Belgium
| | | | - Koen Augustyns
- Laboratory of Medicinal Chemistry, University of Antwerp Antwerp, Belgium
| | - Jurgen Joossens
- Laboratory of Medicinal Chemistry, University of Antwerp Antwerp, Belgium
| | | | | | - Leonie Wyffels
- Faculty of Medicine and Health Sciences, Molecular Imaging Center Antwerp, University of AntwerpAntwerp, Belgium; Nuclear Medicine, University Hospital AntwerpAntwerp, Belgium
| | - Steven Staelens
- Faculty of Medicine and Health Sciences, Molecular Imaging Center Antwerp, University of Antwerp Antwerp, Belgium
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9
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Synthesis and Evaluation of a Zr-89-Labeled Monoclonal Antibody for Immuno-PET Imaging of Amyloid-β Deposition in the Brain. Mol Imaging Biol 2016; 18:598-605. [DOI: 10.1007/s11307-016-0935-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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10
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Viola KL, Klein WL. Amyloid β oligomers in Alzheimer's disease pathogenesis, treatment, and diagnosis. Acta Neuropathol 2015; 129:183-206. [PMID: 25604547 DOI: 10.1007/s00401-015-1386-3] [Citation(s) in RCA: 430] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/11/2015] [Accepted: 01/11/2015] [Indexed: 12/22/2022]
Abstract
Protein aggregation is common to dozens of diseases including prionoses, diabetes, Parkinson's and Alzheimer's. Over the past 15 years, there has been a paradigm shift in understanding the structural basis for these proteinopathies. Precedent for this shift has come from investigation of soluble Aβ oligomers (AβOs), toxins now widely regarded as instigating neuron damage leading to Alzheimer's dementia. Toxic AβOs accumulate in AD brain and constitute long-lived alternatives to the disease-defining Aβ fibrils deposited in amyloid plaques. Key experiments using fibril-free AβO solutions demonstrated that while Aβ is essential for memory loss, the fibrillar Aβ in amyloid deposits is not the agent. The AD-like cellular pathologies induced by AβOs suggest their impact provides a unifying mechanism for AD pathogenesis, explaining why early stage disease is specific for memory and accounting for major facets of AD neuropathology. Alternative ideas for triggering mechanisms are being actively investigated. Some research favors insertion of AβOs into membrane, while other evidence supports ligand-like accumulation at particular synapses. Over a dozen candidate toxin receptors have been proposed. AβO binding triggers a redistribution of critical synaptic proteins and induces hyperactivity in metabotropic and ionotropic glutamate receptors. This leads to Ca(2+) overload and instigates major facets of AD neuropathology, including tau hyperphosphorylation, insulin resistance, oxidative stress, and synapse loss. Because different species of AβOs have been identified, a remaining question is which oligomer is the major pathogenic culprit. The possibility has been raised that more than one species plays a role. Despite some key unknowns, the clinical relevance of AβOs has been established, and new studies are beginning to point to co-morbidities such as diabetes and hypercholesterolemia as etiological factors. Because pathogenic AβOs appear early in the disease, they offer appealing targets for therapeutics and diagnostics. Promising therapeutic strategies include use of CNS insulin signaling enhancers to protect against the presence of toxins and elimination of the toxins through use of highly specific AβO antibodies. An AD-dependent accumulation of AβOs in CSF suggests their potential use as biomarkers and new AβO probes are opening the door to brain imaging. Overall, current evidence indicates that Aβ oligomers provide a substantive molecular basis for the cause, treatment and diagnosis of Alzheimer's disease.
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11
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El Shikh ME, Kmieciak M, Manjili MH, Szakal AK, Pitzalis C, Tew JG. Multi-therapeutic potential of autoantibodies induced by immune complexes trapped on follicular dendritic cells. Hum Vaccin Immunother 2013; 9:2434-44. [PMID: 23836278 PMCID: PMC3981854 DOI: 10.4161/hv.25596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/17/2013] [Accepted: 06/29/2013] [Indexed: 11/19/2022] Open
Abstract
Induction of autoantibodies (autoAbs) targeting disease drivers / mediators is emerging as a potential immunotherapeutic strategy. Auto-immune complex (IC)-retaining follicular dendritic cells (FDCs) critically regulate pathogenic autoAb production in autoreactive germinal centers (GCs); however, their ability to induce potentially therapeutic autoAbs has not been explored. We hypothesized that deliberate display of clinically targeted antigens (Ags) in the form of ICs on FDC membranes induces target-specific autoreactive GCs and autoAbs that may be exploited therapeutically. To test our hypothesis, three therapeutically relevant Ags: TNF-α, HER2/neu and IgE, were investigated. Our results indicated that TNF-α-, HER2/neu- and IgE-specific autoAbs associated with strong GC reactions were induced by TNF-α-, HER2/neu- and IgE-IC retention on FDCs. Moreover, the induced anti-TNF-α autoAbs neutralized mouse and human TNF-α with half maximal Inhibitory Concentration (IC₅₀) of 7.1 and 1.6 nM respectively. In addition, we demonstrated that FDC-induced Ab production could be non-specifically inhibited by the IgG-specific Endo-S that accessed the light zones of GCs and interfered with FDC-IC retention. In conclusion, the ability of FDCs to productively present autoAgs raises the potential for a novel immunotherapeutic platform targeting mediators of autoimmune disorders, allergic diseases, and Ab responsive cancers.
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Affiliation(s)
- Mohey Eldin El Shikh
- Centre for Experimental Medicine and Rheumatology; William Harvey Research Institute; Barts and the London School of Medicine and Dentistry; Queen Mary University of London; London, UK
| | - Maciej Kmieciak
- Department of Microbiology and Immunology; VCU School of Medicine; Richmond, VA USA
- Massey Cancer Centre; VCU School of Medicine; Richmond, VA USA
| | - Masoud H Manjili
- Department of Microbiology and Immunology; VCU School of Medicine; Richmond, VA USA
- Massey Cancer Centre; VCU School of Medicine; Richmond, VA USA
| | - Andras K Szakal
- Anatomy and Neurobiology; VCU School of Medicine; Richmond, VA USA
| | - Costantino Pitzalis
- Centre for Experimental Medicine and Rheumatology; William Harvey Research Institute; Barts and the London School of Medicine and Dentistry; Queen Mary University of London; London, UK
| | - John G Tew
- Department of Microbiology and Immunology; VCU School of Medicine; Richmond, VA USA
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12
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McLean D, Cooke MJ, Albay R, Glabe C, Shoichet MS. Positron emission tomography imaging of fibrillar parenchymal and vascular amyloid-β in TgCRND8 mice. ACS Chem Neurosci 2013; 4:613-23. [PMID: 23509918 DOI: 10.1021/cn300226q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Few quantitative diagnostic and monitoring, tools are available to clinicians treating patients with Alzheimer's disease. Further, many of the promising quantitative imaging tools under development lack clear specificity toward different types of Amyloid-β (Aβ) pathology such as vascular or oligomeric species. Antibodies offer an opportunity to image specific types of Aβ pathology because of their excellent specificity. In this study, we developed a method to translate a panel of anti-Aβ antibodies, which show excellent histological performance, into live animal imaging contrast agents. In the TgCRND8 mouse model of Alzheimer's disease, we tested two antibodies, M64 and M116, that target parenchyma aggregated Aβ plaques and one antibody, M31, that targets vascular Aβ. All three antibodies were administered intravenously after labeling with both poly(ethylene glycol) to enhance circulation and (64)Cu to allow detection via positron emission tomography (PET) imaging. We were clearly able to differentiate TgCRND8 mice from wild type controls by PET imaging using either M116, the anti-Aβ antibody targeting parenchymal Aβ or M31, the antivascular Aβ antibody. To confirm the validity of the noninvasive imaging of specific Aβ pathology, brains were examined after imaging and showed clear evidence of binding to Aβ plaques.
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Affiliation(s)
- Daniel McLean
- Department of Chemical
Engineering
and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Michael J. Cooke
- Department of Chemical
Engineering
and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Ricardo Albay
- Department of Molecular Biology
and Biochemistry, School of Biological Sciences, University of California at Irvine, Irvine, California, United
States
| | - Charles Glabe
- Department of Molecular Biology
and Biochemistry, School of Biological Sciences, University of California at Irvine, Irvine, California, United
States
| | - Molly S. Shoichet
- Department of Chemical
Engineering
and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
- Institute of Biomaterials and
Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department of Chemistry University of Toronto, Toronto, Ontario M5S 3H6, Canada
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