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Miner MWG, Liljenbäck H, Virta J, Kärnä S, Viitanen R, Elo P, Gardberg M, Teuho J, Saipa P, Rajander J, Mansour HMA, Cleveland NA, Low PS, Li XG, Roivainen A. High folate receptor expression in gliomas can be detected in vivo using folate-based positron emission tomography with high tumor-to-brain uptake ratio divulging potential future targeting possibilities. Front Immunol 2023; 14:1145473. [PMID: 37275898 PMCID: PMC10232737 DOI: 10.3389/fimmu.2023.1145473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/28/2023] [Indexed: 06/07/2023] Open
Abstract
Introduction Non-invasive imaging techniques such as positron emission tomography (PET) are extremely important for cancer detection and characterization especially for difficult to biopsy or extremely delicate organs such as the brain. The folate analogue 1,4,7-triazacylononane-1,4,7-triacetic acid-conjugated folate radiolabeled with aluminum fluoride-18 ([18F]FOL) has been previously shown to accumulate preferentially in tumor cells with an overexpression of folate receptors (FRs) and here was investigated for its ability to detect orthotopic gliomas in a rat model. In addition, we studied the expression of FRs in human glioblastoma samples to investigate if an analogous relationship may exist. Methods Nine BDIX rats were injected with BT4C rat glioma cells into the right hemisphere of the brain. Animals were imaged with gadolinium-enhanced magnetic resonance imaging at on days prior to PET/computed tomography (CT) imaging. Animals were divided into two groups, and were PET/CT imaged with either [18F]FOL or 2-deoxy-2-18F-fluoro-D-glucose ([18F]FDG) on 19 and 32-days post glioma grafting. Two subjects were also PET/CT imaged with [18F]FOL on day 16. Biodistribution was studied and brains were cryosectioned for autoradiography, immunofluorescence, and histological studies. Patient-derived paraffin-embedded glioblastomas were sectioned and stained with similar methods. Results PET imaging showed an increase of [18F]FOL tumor-to-brain uptake ratio (TBR) over the study duration from day 16/19 (3.3 ± 0.9) increasing to 5.7 ± 1.0 by day 32. [18F]FDG PET-imaged rats had a consistent TBR of 1.6 ± 0.1 throughout the study. Ex vivo autoradiography results revealed an exceptionally high TBR of 116.1 ± 26.9 for [18F]FOL while the [18F]FDG values were significantly lower giving 2.9 ± 0.6 (P<0.0001). Immunostaining demonstrated an increased presence of FR-α in the BT4C gliomas versus the contralateral brain tissue, while FR-β was present only on glioma periphery. Human sections assayed showed similar FRs expression characteristics. Conclusion This study shows upregulation of FR-α inside glioma regions in both human and animal tissue, providing a biochemical basis for the observed increased [18F]FOL uptake in animal PET images. These results suggest that FRs targeting imaging and therapeutic compounds may possess clinically relevant translational abilities for the detection and treatment of gliomas.
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Affiliation(s)
| | - Heidi Liljenbäck
- Turku PET Centre, University of Turku, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Jenni Virta
- Turku PET Centre, University of Turku, Turku, Finland
| | - Salli Kärnä
- Turku PET Centre, University of Turku, Turku, Finland
| | | | - Petri Elo
- Turku PET Centre, University of Turku, Turku, Finland
| | - Maria Gardberg
- Department of Pathology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Jarmo Teuho
- Turku PET Centre, University of Turku, Turku, Finland
- Turku PET Centre, Turku University Hospital, Turku, Finland
- Department of Medical Physics, Turku University Hospital, Turku, Finland
| | - Piritta Saipa
- Turku PET Centre, University of Turku, Turku, Finland
| | - Johan Rajander
- Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Turku, Finland
| | | | - Nathan A. Cleveland
- Department of Chemistry, Purdue University, West Lafayette, IN, United States
| | - Philip S. Low
- Department of Chemistry, Purdue University, West Lafayette, IN, United States
| | - Xiang-Guo Li
- Turku PET Centre, University of Turku, Turku, Finland
- Department of Chemistry, University of Turku, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland
| | - Anne Roivainen
- Turku PET Centre, University of Turku, Turku, Finland
- Turku Center for Disease Modeling, University of Turku, Turku, Finland
- Turku PET Centre, Turku University Hospital, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland
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2
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Calvillo-Robledo A, Ramírez-Farías C, Valdez-Urias F, Huerta-Carreón EP, Quintanar-Stephano A. Arginine vasopressin hormone receptor antagonists in experimental autoimmune encephalomyelitis rodent models: A new approach for human multiple sclerosis treatment. Front Neurosci 2023; 17:1138627. [PMID: 36998727 PMCID: PMC10043225 DOI: 10.3389/fnins.2023.1138627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic demyelinating and neurodegenerative disease that affects the central nervous system. MS is a heterogeneous disorder of multiple factors that are mainly associated with the immune system including the breakdown of the blood-brain and spinal cord barriers induced by T cells, B cells, antigen presenting cells, and immune components such as chemokines and pro-inflammatory cytokines. The incidence of MS has been increasing worldwide recently, and most therapies related to its treatment are associated with the development of several secondary effects, such as headaches, hepatotoxicity, leukopenia, and some types of cancer; therefore, the search for an effective treatment is ongoing. The use of animal models of MS continues to be an important option for extrapolating new treatments. Experimental autoimmune encephalomyelitis (EAE) replicates the several pathophysiological features of MS development and clinical signs, to obtain a potential treatment for MS in humans and improve the disease prognosis. Currently, the exploration of neuro-immune-endocrine interactions represents a highlight of interest in the treatment of immune disorders. The arginine vasopressin hormone (AVP) is involved in the increase in blood−brain barrier permeability, inducing the development and aggressiveness of the disease in the EAE model, whereas its deficiency improves the clinical signs of the disease. Therefore, this present review discussed on the use of conivaptan a blocker of AVP receptors type 1a and type 2 (V1a and V2 AVP) in the modulation of immune response without completely depleting its activity, minimizing the adverse effects associated with the conventional therapies becoming a potential therapeutic target in the treatment of patients with multiple sclerosis.
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3
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Buttigieg E, Scheller A, El Waly B, Kirchhoff F, Debarbieux F. Contribution of Intravital Neuroimaging to Study Animal Models of Multiple Sclerosis. Neurotherapeutics 2023; 20:22-38. [PMID: 36653665 PMCID: PMC10119369 DOI: 10.1007/s13311-022-01324-6] [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] [Accepted: 10/23/2022] [Indexed: 01/20/2023] Open
Abstract
Multiple sclerosis (MS) is a complex and long-lasting neurodegenerative disease of the central nervous system (CNS), characterized by the loss of myelin within the white matter and cortical fibers, axonopathy, and inflammatory responses leading to consequent sensory-motor and cognitive deficits of patients. While complete resolution of the disease is not yet a reality, partial tissue repair has been observed in patients which offers hope for therapeutic strategies. To address the molecular and cellular events of the pathomechanisms, a variety of animal models have been developed to investigate distinct aspects of MS disease. Recent advances of multiscale intravital imaging facilitated the direct in vivo analysis of MS in the animal models with perspective of clinical transfer to patients. This review gives an overview of MS animal models, focusing on the current imaging modalities at the microscopic and macroscopic levels and emphasizing the importance of multimodal approaches to improve our understanding of the disease and minimize the use of animals.
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Affiliation(s)
- Emeline Buttigieg
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
| | - Bilal El Waly
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany
| | - Franck Debarbieux
- Institut des Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS UMR7289, 13005, Marseille, France.
- Centre Européen de Recherche en Imagerie Médicale (CERIMED), Aix-Marseille Université, Marseille, France.
- Institut Universitaire de France (IUF), Paris, France.
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4
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Herr SA, Gardeen SS, Low PS, Shi R. Targeted delivery of acrolein scavenger hydralazine in spinal cord injury using folate-linker-drug conjugation. Free Radic Biol Med 2022; 184:66-73. [PMID: 35398493 DOI: 10.1016/j.freeradbiomed.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/30/2022] [Accepted: 04/03/2022] [Indexed: 11/26/2022]
Abstract
Oxidative stress has been shown to play a critical pathogenic role in functional loss after spinal cord injury (SCI). As a direct result of oxidative stress, lipid peroxidation-derived aldehydes have emerged as key culprits that sustain secondary injury and contribute significantly to pathological outcomes. Acrolein, a neurotoxin, has been shown to be elevated in SCI and can result in post-SCI neurological deficits. Reducing acrolein has therefore emerged as a novel and effective therapeutic strategy in SCI. Previous studies have revealed that hydralazine, an FDA approved blood pressure lowering medication, when administered after SCI shows strong acrolein scavenging capabilities and significantly improves cellular and behavioral outcomes. However, while effective at scavenging acrolein, hydralazine's blood pressure lowering activity can have a detrimental impact on neurotrauma patients. Here, our goal was to preserve the acrolein scavenging capability while mitigating the effect of hydralazine on blood pressure. We accomplished this using a folate-targeted delivery system to deploy hydralazine to the folate receptor positive inflammatory site of the cord injury. Using a model of rat SCI, we found that this system is effective for targeting the injury site, and that folate targeted hydralazine can scavenge acrolein without significantly impacting blood pressure.
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Affiliation(s)
- Seth A Herr
- Center for Paralysis Research & Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University. Lynn Hall, 625 N Harrison St. West Lafayette, IN, 47907, USA.
| | - Spencer S Gardeen
- Department of Chemistry, College of Science, Purdue University. Drug Discovery Building, 720 Clinic Dr. West Lafayette, IN, 47907, USA.
| | - Philip S Low
- Department of Chemistry, College of Science, Purdue University. Drug Discovery Building, 720 Clinic Dr. West Lafayette, IN, 47907, USA.
| | - Riyi Shi
- Center for Paralysis Research & Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University. Lynn Hall, 625 N Harrison St. West Lafayette, IN, 47907, USA.
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5
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Nylund M, Sucksdorff M, Matilainen M, Polvinen E, Tuisku J, Airas L. Phenotyping of multiple sclerosis lesions according to innate immune cell activation using 18 kDa translocator protein-PET. Brain Commun 2022; 4:fcab301. [PMID: 34993478 PMCID: PMC8727984 DOI: 10.1093/braincomms/fcab301] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 12/27/2022] Open
Abstract
Chronic active lesions are promotors of neurodegeneration and disease progression in multiple sclerosis. They harbour a dense rim of activated innate immune cells at the lesion edge, which promotes lesion growth and thereby induces damage. Conventional MRI is of limited help in identifying the chronic active lesions, so alternative imaging modalities are needed. Objectives were to develop a PET-based automated analysis method for phenotyping of chronic lesions based on lesion-associated innate immune cell activation and to comprehensively evaluate the prevalence of these lesions in the various clinical subtypes of multiple sclerosis, and their association with disability. In this work, we use 18 kDa translocator protein-PET imaging for phenotyping chronic multiple sclerosis lesions at a large scale. For this, we identified 1510 white matter T1-hypointense lesions from 91 multiple sclerosis patients (67 relapsing–remitting patients and 24 secondary progressive patients). Innate immune cell activation at the lesion rim was measured using PET imaging and the 18 kDa translocator protein-binding radioligand 11C-PK11195. A T1-hypointense lesion was classified as rim-active if the distribution volume ratio of 11C-PK11195-binding was low in the plaque core and considerably higher at the plaque edge. If no significant ligand binding was observed, the lesion was classified as inactive. Plaques that had considerable ligand binding both in the core and at the rim were classified as overall-active. Conventional MRI and disability assessment using the Expanded Disability Status Scale were performed at the time of PET imaging. In the secondary progressive cohort, an average of 19% (median, interquartile range: 11–26) of T1 lesions were rim-active in each individual patient, compared to 10% (interquartile range: 0–20) among relapsing–remitting patients (P = 0.009). Secondary progressive patients had a median of 3 (range: 0–11) rim-active lesions, versus 1 (range: 0–18) among relapsing–remitting patients (P = 0.029). Among those patients who had rim-active lesions (n = 63), the average number of active voxels at the rim was higher among secondary progressive compared to relapsing–remitting patients (median 158 versus 74; P = 0.022). The number of active voxels at the rim correlated significantly with the Expanded Disability Status Scale (R = 0.43, P < 0.001), and the volume of the rim-active lesions similarly correlated with the Expanded Disability Status Scale (R = 0.45, P < 0.001). Our study is the first to report in vivo phenotyping of chronic lesions at large scale, based on 18 kDa translocator protein-PET. Patients with higher disability displayed a higher proportion of rim-active lesions. The in vivo lesion phenotyping methodology offers a new tool for individual assessment of smouldering (rim-active) lesion burden.
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Affiliation(s)
- Marjo Nylund
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Marcus Sucksdorff
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Markus Matilainen
- Turku PET Centre, Turku, Finland.,Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Eero Polvinen
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | | | - Laura Airas
- Turku PET Centre, Turku, Finland.,Clinical Neurosciences, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
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6
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Van Camp N, Lavisse S, Roost P, Gubinelli F, Hillmer A, Boutin H. TSPO imaging in animal models of brain diseases. Eur J Nucl Med Mol Imaging 2021; 49:77-109. [PMID: 34245328 PMCID: PMC8712305 DOI: 10.1007/s00259-021-05379-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/25/2021] [Indexed: 12/19/2022]
Abstract
Over the last 30 years, the 18-kDa TSPO protein has been considered as the PET imaging biomarker of reference to measure increased neuroinflammation. Generally assumed to image activated microglia, TSPO has also been detected in endothelial cells and activated astrocytes. Here, we provide an exhaustive overview of the recent literature on the TSPO-PET imaging (i) in the search and development of new TSPO tracers and (ii) in the understanding of acute and chronic neuroinflammation in animal models of neurological disorders. Generally, studies testing new TSPO radiotracers against the prototypic [11C]-R-PK11195 or more recent competitors use models of acute focal neuroinflammation (e.g. stroke or lipopolysaccharide injection). These studies have led to the development of over 60 new tracers during the last 15 years. These studies highlighted that interpretation of TSPO-PET is easier in acute models of focal lesions, whereas in chronic models with lower or diffuse microglial activation, such as models of Alzheimer's disease or Parkinson's disease, TSPO quantification for detection of neuroinflammation is more challenging, mirroring what is observed in clinic. Moreover, technical limitations of preclinical scanners provide a drawback when studying modest neuroinflammation in small brains (e.g. in mice). Overall, this review underlines the value of TSPO imaging to study the time course or response to treatment of neuroinflammation in acute or chronic models of diseases. As such, TSPO remains the gold standard biomarker reference for neuroinflammation, waiting for new radioligands for other, more specific targets for neuroinflammatory processes and/or immune cells to emerge.
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Affiliation(s)
- Nadja Van Camp
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Sonia Lavisse
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Pauline Roost
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Francesco Gubinelli
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Ansel Hillmer
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, CT, USA
| | - Hervé Boutin
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, M13 9PL, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, 27 Palatine Road, M20 3LJ, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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7
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CAR-T cell-mediated depletion of immunosuppressive tumor-associated macrophages promotes endogenous antitumor immunity and augments adoptive immunotherapy. Nat Commun 2021; 12:877. [PMID: 33563975 PMCID: PMC7873057 DOI: 10.1038/s41467-021-20893-2] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022] Open
Abstract
The immunosuppressive tumor microenvironment (TME) represents a major barrier for effective immunotherapy. Tumor-associated macrophages (TAMs) are highly heterogeneous and plastic cell components of the TME which can either promote tumor progression (M2-like) or boost antitumor immunity (M1-like). Here, we demonstrate that a subset of TAMs that express folate receptor β (FRβ) possess an immunosuppressive M2-like profile. In syngeneic tumor mouse models, chimeric antigen receptor (CAR)-T cell-mediated selective elimination of FRβ+ TAMs in the TME results in an enrichment of pro-inflammatory monocytes, an influx of endogenous tumor-specific CD8+ T cells, delayed tumor progression, and prolonged survival. Preconditioning of the TME with FRβ-specific CAR-T cells also improves the effectiveness of tumor-directed anti-mesothelin CAR-T cells, while simultaneous co-administration of both CAR products does not. These results highlight the pro-tumor role of FRβ+ TAMs in the TME and the therapeutic implications of TAM-depleting agents as preparative adjuncts to conventional immunotherapies that directly target tumor antigens.
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8
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Cresswell GM, Wang B, Kischuk EM, Broman MM, Alfar RA, Vickman RE, Dimitrov DS, Kularatne SA, Sundaram CP, Singhal S, Eruslanov EB, Crist SA, Elzey BD, Ratliff TL, Low PS. Folate Receptor Beta Designates Immunosuppressive Tumor-Associated Myeloid Cells That Can Be Reprogrammed with Folate-Targeted Drugs. Cancer Res 2021; 81:671-684. [PMID: 33203700 PMCID: PMC10987201 DOI: 10.1158/0008-5472.can-20-1414] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/02/2020] [Accepted: 11/12/2020] [Indexed: 11/16/2022]
Abstract
Although immunotherapies of tumors have demonstrated promise for altering the progression of malignancies, immunotherapies have been limited by an immunosuppressive tumor microenvironment (TME) that prevents infiltrating immune cells from performing their anticancer functions. Prominent among immunosuppressive cells are myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) that inhibit T cells via release of immunosuppressive cytokines and engagement of checkpoint receptors. Here, we explore the properties of MDSCs and TAMs from freshly isolated mouse and human tumors and find that an immunosuppressive subset of these cells can be distinguished from the nonimmunosuppressive population by its upregulation of folate receptor beta (FRβ) within the TME and its restriction to the TME. This FRβ+ subpopulation could be selectively targeted with folate-linked drugs. Delivery of a folate-targeted TLR7 agonist to these cells (i) reduced their immunosuppressive function, (ii) increased CD8+ T-cell infiltration, (iii) enhanced M1/M2 macrophage ratios, (iv) inhibited tumor growth, (v) blocked tumor metastasis, and (vi) improved overall survival without demonstrable toxicity. These data reveal a broadly applicable strategy across tumor types for reprogramming MDSCs and TAMs into antitumorigenic immune cells using a drug that would otherwise be too toxic to administer systemically. The data also establish FRβ as the first marker that distinguishes immunosuppressive from nonimmunosuppressive subsets of MDSCs and TAMs. Because all solid tumors accumulate MDSCs and TAMs, a general strategy to both identify and reprogram these cells should be broadly applied in the characterization and treatment of multiple tumors. SIGNIFICANCE: FRβ serves as both a means to identify and target MDSCs and TAMs within the tumor, allowing for delivery of immunomodulatory compounds to tumor myeloid cells in a variety of cancers.
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Affiliation(s)
| | - Bingbing Wang
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Erin M Kischuk
- Department of Comparative Pathobiology, West Lafayette, Indiana
| | | | - Rami A Alfar
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Renee E Vickman
- Department of Comparative Pathobiology, West Lafayette, Indiana
| | - Dimiter S Dimitrov
- Center for Antibody Therapeutics, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | | | - Sunil Singhal
- Perelman School of Medicine, Penn Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Evgeniy B Eruslanov
- Perelman School of Medicine, Penn Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Scott A Crist
- Department of Comparative Pathobiology, West Lafayette, Indiana
| | - Bennett D Elzey
- Department of Comparative Pathobiology, West Lafayette, Indiana
- Department of Urology, IU School of Medicine, Indiana University Purdue University Indianapolis, Indianapolis, Indiana
| | - Timothy L Ratliff
- Department of Comparative Pathobiology, West Lafayette, Indiana.
- Purdue University Center for Cancer Research, West Lafayette, Indiana
| | - Philip S Low
- Department of Chemistry, Purdue University, West Lafayette, Indiana.
- Purdue University Center for Cancer Research, West Lafayette, Indiana
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana
- Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana
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9
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Elo P, Li XG, Liljenbäck H, Gardberg M, Moisio O, Miner M, Virta J, Saraste A, Srinivasarao M, Pugh M, Low PS, Knuuti J, Jalkanen S, Airas L, Lu YJ, Roivainen A. Efficacy and tolerability of folate-aminopterin therapy in a rat focal model of multiple sclerosis. J Neuroinflammation 2021; 18:30. [PMID: 33472663 PMCID: PMC7819223 DOI: 10.1186/s12974-021-02073-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 01/05/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Activated macrophages in the experimental model of multiple sclerosis (MS) express folate receptor-β (FR-β), representing a promising target for the treatment of MS. Here, we both evaluated the efficacy of a novel folate-aminopterin construct (EC2319) in a rat focal model of multiple sclerosis (MS) and investigated the utility of 68Ga-labeled 1,4,7-triazacyclononane-1,4,7-triacetic acid-conjugated folate (68Ga-FOL) for assessing inflammatory lesions. In addition, we investigated whether FR-β is expressed in the brain of patients with MS. METHODS Focal delayed-type hypersensitivity experimental autoimmune encephalomyelitis (fDTH-EAE) was induced in 40 Lewis rats; 20 healthy Lewis rats were used as controls. Rats were divided into six groups according to the duration of disease (control, acute, or chronic) and intervention (vehicle versus EC2319). 68Ga-FOL analyses, histology, and immunofluorescence of the brain were performed to evaluate the efficacy of subcutaneously administered EC2319 on lesion development. Immunofluorescence was used to assess FR-β expression in postmortem brain samples from 5 patients with MS and 5 healthy controls. RESULTS Immunofluorescence and histological analyses revealed significant reductions in FR-β expression (P < 0.05) and lesion size (P < 0.01), as well as improved inducible nitric oxide synthase/mannose receptor C type 1 ratios (P < 0.01) in macrophages and microglia during the chronic but not acute phase of fDTH-EAE in EC2319-treated rats. The uptake of IV-injected 68Ga-FOL in the brain was low and did not differ between the groups, but the in vitro binding of 68Ga-FOL was significantly lower in EC2319-treated rats (P < 0.01). FR-β positivity was observed in chronically active lesions and in normal-appearing white matter in MS brain samples. CONCLUSIONS EC2319 was well tolerated and attenuated inflammation and lesion development in a rat model of a chronic progressive form of MS. Human MS patients have FR-β-positive cells in chronically active plaques, which suggests that these results may have translational relevance.
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Affiliation(s)
- Petri Elo
- Turku PET Centre, University of Turku, Turku, Finland
| | - Xiang-Guo Li
- Turku PET Centre, University of Turku, Turku, Finland.,Turku PET Centre, Åbo Akademi University, Turku, Finland
| | - Heidi Liljenbäck
- Turku PET Centre, University of Turku, Turku, Finland.,Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Maria Gardberg
- Department of Pathology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Olli Moisio
- Turku PET Centre, University of Turku, Turku, Finland
| | - Maxwell Miner
- Turku PET Centre, University of Turku, Turku, Finland
| | - Jenni Virta
- Turku PET Centre, University of Turku, Turku, Finland
| | - Antti Saraste
- Turku PET Centre, University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital, Turku, Finland
| | | | - Michael Pugh
- Endocyte, Inc., now part of Novartis Institutes for Biomedical Research, West Lafayette, IN, USA
| | - Philip S Low
- Department of Chemistry, Purdue University, West Lafayette, IN, USA
| | - Juhani Knuuti
- Turku PET Centre, University of Turku, Turku, Finland.,Turku PET Centre, Åbo Akademi University, Turku, Finland.,Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Sirpa Jalkanen
- MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Laura Airas
- Department of Neurology, Turku University Hospital, Turku, Finland
| | - Yingjuan June Lu
- Endocyte, Inc., now part of Novartis Institutes for Biomedical Research, West Lafayette, IN, USA
| | - Anne Roivainen
- Turku PET Centre, University of Turku, Turku, Finland. .,Turku Center for Disease Modeling, University of Turku, Turku, Finland. .,Turku PET Centre, Turku University Hospital, Turku, Finland.
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Radiosynthesis and preclinical evaluation of [ 68Ga]Ga-NOTA-folate for PET imaging of folate receptor β-positive macrophages. Sci Rep 2020; 10:13593. [PMID: 32788595 PMCID: PMC7423886 DOI: 10.1038/s41598-020-70394-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/27/2020] [Indexed: 11/09/2022] Open
Abstract
Folate receptor β (FR-β), a marker expressed on macrophages, is a promising target for imaging of inflammation. Here, we report the radiosynthesis and preclinical evaluation of [68Ga]Ga-NOTA-folate (68Ga-FOL). After determining the affinity of 68Ga-FOL using cells expressing FR-β, we studied atherosclerotic mice with 68Ga-FOL and 18F-FDG PET/CT. In addition, we studied tracer distribution and co-localization with macrophages in aorta cryosections using autoradiography, histology, and immunostaining. The specificity of 68Ga-FOL was assessed in a blocking study with folate glucosamine. As a final step, human radiation doses were extrapolated from rat PET data. We were able to produce 68Ga-FOL with high radiochemical purity and moderate molar activity. Cell binding studies revealed that 68Ga-FOL had 5.1 nM affinity for FR-β. Myocardial uptake of 68Ga-FOL was 20-fold lower than that of 18F-FDG. Autoradiography and immunohistochemistry of the aorta revealed that 68Ga-FOL radioactivity co-localized with Mac-3–positive macrophage-rich atherosclerotic plaques. The plaque-to-healthy vessel wall ratio of 68Ga-FOL was significantly higher than that of 18F-FDG. Blocking studies verified that 68Ga-FOL was specific for FR. Based on estimations from rat data, the human effective dose was 0.0105 mSv/MBq. Together, these findings show that 68Ga-FOL represents a promising new FR-β–targeted tracer for imaging macrophage-associated inflammation.
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