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Frigerio B, Franssen G, Luison E, Satta A, Seregni E, Colombatti M, Fracasso G, Valdagni R, Mezzanzanica D, Boerman O, Canevari S, Figini M. Full preclinical validation of the 123I-labeled anti-PSMA antibody fragment ScFvD2B for prostate cancer imaging. Oncotarget 2017; 8:10919-10930. [PMID: 28051996 PMCID: PMC5355234 DOI: 10.18632/oncotarget.14229] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 01/12/2023] Open
Abstract
Purpose In the context of prostate cancer (PCa) imaging, the aim of this study was to optimize (in vitro) the specificity and assess preclinically (in vivo) the tumor targeting properties of the 123I-scFvD2B antibody specific for prostate-specific membrane antigen (PSMA). Experimental Design The 123I-labeling conditions of the antibody fragment scFvD2B, produced in an eukaryotic system under GMP-compliant conditions, were optimized and assessed for purity and immunoreactivity. The specificity and potency of tumor uptake were tested in three preclinical in vivo models of subcutaneously xenografted human tumors expressing different levels of PSMA (LNCaP, naturally expressing PSMA; PC3-PIP and LS174T-PSMA, transfected with PSMA) or PC3 and LS174T, as negative controls, to assess the clearance, biodistribution and imaging potential of 123I-scFvD2B. Results The set conditions of production and radiolabeling yielded a reagent suitable for human delivery thanks to the purity of the formulation and the high immunoreactivity. In all preclinical models 123I-scFvD2B showed specific targeting only to PSMA-positive tumors with the final specific activity ranging up to 1500 MBq/mg. Despite different levels of PSMA expression, biodistribution analyses and SPECT/CT imaging demonstrated similar results and maximal signal-to-background ratios 24 hours after injection. Conclusions Due to its in vitro and in vivo properties, 123I-scFvD2B could be a promising tool for the early diagnosis of PCa, and may represent a molecular imaging option to monitor disease progression and assist in the clinical management of PCa patients.
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Affiliation(s)
- Barbara Frigerio
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Gerben Franssen
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elena Luison
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Alessandro Satta
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Ettore Seregni
- S.C. Nuclear Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | | | | | - Riccardo Valdagni
- Department of Oncology and Hemato-Oncology, Università degli Studi di Milano, Radiation Oncology 1, Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Delia Mezzanzanica
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Otto Boerman
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Silvana Canevari
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Mariangela Figini
- Department of Experimental Oncology and Molecular Medicine, S.S. Molecular Therapies, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
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Monoclonal antibodies to host cellular receptors for the treatment and prevention of HIV-1 infection. Curr Opin HIV AIDS 2016; 10:144-50. [PMID: 25700204 DOI: 10.1097/coh.0000000000000146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Clinically relevant monoclonal antibodies (mAb) to host cellular receptors have been generated to both the CD4 receptor and the CCR5 coreceptor, cell surface proteins critical for HIV-1 entry. Ibalizumab is a novel humanized mAb that binds to a conformational epitope on CD4 and blocks entry of HIV-1. It has broad and potent antiviral activity in vitro and in vivo. PRO 140 is a humanized mAb that binds to the CCR5 coreceptor and inhibits CCR5-tropic HIV-1 by interfering with viral entry. Antiviral activity has been demonstrated both in vitro against R5 viruses and in vivo in HIV-1-infected individuals harboring CCR5-tropic virus. RECENT FINDINGS Both antibodies have been administered intravenously in early-phase clinical trials, and current emphasis is on the development of formulations that can be administered subcutaneously. Most recently, bispecific antibodies combining either ibalizumab or PRO 140 with anti-Env broadly neutralizing antibodies have been constructed with vastly improved in-vitro neutralizing profiles, and may offer substantial advantages in the clinic. SUMMARY mAb to host cellular receptors particularly when combined with broadly neutralizing antibodies in novel conformations may offer advances in both the treatment and prevention of HIV-1 infection.
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Sironi F, Malnati M, Mongelli N, Cozzi P, Guzzo C, Ghezzi S, Martínez-Romero C, García-Sastre A, Lusso P, Jabes D, Biswas P. Characterization of HIV-1 entry inhibitors with broad activity against R5 and X4 viral strains. J Transl Med 2015; 13:107. [PMID: 25888743 PMCID: PMC4399250 DOI: 10.1186/s12967-015-0461-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/11/2015] [Indexed: 12/04/2022] Open
Abstract
Background Combined antiretroviral therapy has drastically reduced mortality and morbidity of HIV-infected individuals. Nevertheless long-term toxicity and appearance of viral resistance hampers the prolonged effectiveness of combination therapy, requiring a continuous input of drugs to replace those utilized in combination regimens. We here investigated the anti-HIV activity of novel derivatives of the suradista chemical class. Methods Compounds were tested on acute HIV-1 infection of activated peripheral blood mononuclear cells. HIV production was monitored by enzyme-linked immunosorbent assay measuring the protein p24 released in culture supernatants. Fusion assays were carried out to study the mechanism of action of these compounds. A modified version of a previously established recombinant vaccinia virus-based assay was used measuring activation of a reporter gene upon fusion of two distinct cell populations. Flow cytometry was performed in competition assays for the binding of several antibodies targeting different sites of the viral envelope glycoprotein gp120, or the receptor CD4, or the coreceptors CXCR4 and CCR5. Results Four compounds inhibited replication of a prototypic R5 (BaL) and X4 (IIIB) laboratory-adapted HIV-1 strain at low micromolar concentrations, in the absence of cytotoxicity. Approximately a ten fold greater activity was achieved against the X4 as compared to the R5 strain. The compounds blocked X4 and R5 HIV-1 fusion, a step of viral entry. This activity appeared specific for HIV-1, as entry of human herpesvirus 6 (HHV-6) and influenza virus was not substantially affected. Further investigation of the inhibitory mechanism revealed that these new molecules target the viral envelope, rather than the coreceptors, as previously shown for a congener of the same class characterized by a long plasmatic half-life. Indeed ND-4043, the most active compound, specifically competed with binding of monoclonal antibodies against the CD4-binding site (CD4-BS) and coreceptor-binding site (CoR-BS) of gp120. These compounds displayed broad anti-HIV activity, as they inhibited various primary R5, X4 and, importantly, dualtropic R5X4 HIV-1 isolates. Of the four derivatives tested, the dimeric compounds were consistently more potent than the monomeric ones. Conclusions Given their unique features, these molecules represent promising candidates for further development and exploitation as anti-HIV therapeutics. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0461-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Francesca Sironi
- Unit of Human Virology, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.
| | - Mauro Malnati
- Unit of Human Virology, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.
| | | | | | - Christina Guzzo
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, 20892, USA.
| | - Silvia Ghezzi
- Unit of Viral Pathogens and Biosafety, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.
| | - Carles Martínez-Romero
- Department of Microbiology, New York, NY, 10029, USA. .,Global Health and Emerging Pathogens Institute, New York, NY, 10029, USA.
| | - Adolfo García-Sastre
- Department of Microbiology, New York, NY, 10029, USA. .,Global Health and Emerging Pathogens Institute, New York, NY, 10029, USA. .,Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Paolo Lusso
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, 20892, USA.
| | - Daniela Jabes
- NeED Pharmaceuticals srl, Viale Ortles 22/4, 20139, Milan, Italy.
| | - Priscilla Biswas
- Unit of Molecular Immunology, Division of Genetics and Cell Biology, San Raffaele Hospital, Via Olgettina 60, 20132, Milan, Italy.
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Guzzo C, Fox J, Lin Y, Miao H, Cimbro R, Volkman BF, Fauci AS, Lusso P. The CD8-derived chemokine XCL1/lymphotactin is a conformation-dependent, broad-spectrum inhibitor of HIV-1. PLoS Pathog 2013; 9:e1003852. [PMID: 24385911 PMCID: PMC3873461 DOI: 10.1371/journal.ppat.1003852] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 11/11/2013] [Indexed: 11/19/2022] Open
Abstract
CD8+ T cells play a key role in the in vivo control of HIV-1 replication via their cytolytic activity as well as their ability to secrete non-lytic soluble suppressive factors. Although the chemokines that naturally bind CCR5 (CCL3/MIP-1α, CCL4/MIP- 1β, CCL5/RANTES) are major components of the CD8-derived anti-HIV activity, evidence indicates the existence of additional, still undefined, CD8-derived HIV-suppressive factors. Here, we report the characterization of a novel anti-HIV chemokine, XCL1/lymphotactin, a member of the C-chemokine family that is produced primarily by activated CD8+ T cells and behaves as a metamorphic protein, interconverting between two structurally distinct conformations (classic and alternative). We found that XCL1 inhibits a broad spectrum of HIV-1 isolates, irrespective of their coreceptor-usage phenotype. Experiments with stabilized variants of XCL1 demonstrated that HIV-1 inhibition requires access to the alternative, all-β conformation, which interacts with proteoglycans but does not bind/activate the specific XCR1 receptor, while the classic XCL1 conformation is inactive. HIV-1 inhibition by XCL1 was shown to occur at an early stage of infection, via blockade of viral attachment and entry into host cells. Analogous to the recently described anti-HIV effect of the CXC chemokine CXCL4/PF4, XCL1-mediated inhibition is associated with direct interaction of the chemokine with the HIV-1 envelope. These results may open new perspectives for understanding the mechanisms of HIV-1 control and reveal new molecular targets for the design of effective therapeutic and preventive strategies against HIV-1. Although HIV, the causative agent of AIDS, establishes a lifelong infection that cannot be eradicated even with effective treatment, the host immune system has the ability to contain its replication for many years in which the disease remains asymptomatic. Key players in HIV control are CD8+ T cells, specialized immune cells that can not only destroy infected cells, but also secrete soluble factors that suppress the virus without killing infected cells. CD8+ T cells produce multiple HIV-suppressive factors, including certain chemokines (soluble proteins that attract immune cells), which block the virus even before it can gain access to its target cells. In the present study, we characterize a new anti-HIV chemokine, XCL1 or lymphotactin, which is primarily produced by CD8+ T cells. A unique feature of XCL1 is that, unlike other antiviral chemokines, it has a very broad spectrum of activity against different variants of HIV-1 and directly binds the virus outer coat, rather than blocking specific receptors on the target cell. Also unique is that fact that XCL1 adopts two possible conformations, and only one of them is capable of HIV inhibition. These findings may open new avenues for the design of effective drugs or vaccines against HIV.
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Affiliation(s)
- Christina Guzzo
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jamie Fox
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yin Lin
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Huiyi Miao
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Raffaello Cimbro
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian F. Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Anthony S. Fauci
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Paolo Lusso
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Frigerio B, Fracasso G, Luison E, Cingarlini S, Mortarino M, Coliva A, Seregni E, Bombardieri E, Zuccolotto G, Rosato A, Colombatti M, Canevari S, Figini M. A single-chain fragment against prostate specific membrane antigen as a tool to build theranostic reagents for prostate cancer. Eur J Cancer 2013; 49:2223-32. [PMID: 23433847 DOI: 10.1016/j.ejca.2013.01.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/24/2013] [Accepted: 01/26/2013] [Indexed: 10/27/2022]
Abstract
Prostate carcinoma is the most common non-cutaneous cancer in developed countries and represents the second leading cause of death. Early stage androgen dependent prostate carcinoma responds well to conventional therapies, but relatively few treatment options exist for patients with hormone-refractory prostate cancer. One of the most suitable targets for antibody-mediated approaches is prostate specific membrane antigen (PSMA) which is a well known tumour associated antigen. PSMA is a type II integral cell-surface membrane protein that is not secreted, and its expression density and enzymatic activity are increased progressively in prostate cancer compared to normal prostate epithelium, thereby making PSMA an ideal target for monoclonal antibody imaging and therapy. To obtain a small protein that can better penetrate tissue, we have engineered a single-chain variable fragment (scFv) starting from the variable heavy and light domains of the murine anti-PSMA monoclonal antibody D2B. scFvD2B was analysed in vitro for activity, stability, internalisation ability and in vivo for targeting specificity. Maintenance of function and immunoreactivity as well as extremely high radiolabelling efficiency and radiochemical purity were demonstrated by in vitro assays and under different experimental conditions. Despite its monovalent binding, scFvD2B retained a good strength of binding and was able to internalise around 40% of bound antigen. In vivo we showed its ability to specifically target only PSMA expressing prostate cancer xenografts. Due to these advantageous properties, scFvD2B has the potential to become a good theranostic reagent for early detection and therapy of prostate cancers.
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Affiliation(s)
- B Frigerio
- Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - G Fracasso
- Department of Pathology and Diagnostics, Section of Immunology, University of Verona, Verona, Italy
| | - E Luison
- Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - S Cingarlini
- Medical Oncology, Azienda Ospedaliera Universitaria Integrata (AOUI), Verona, Italy
| | - M Mortarino
- Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - A Coliva
- Department of Diagnostic Imaging and Radiotherapy, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - E Seregni
- Department of Diagnostic Imaging and Radiotherapy, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - E Bombardieri
- Department of Diagnostic Imaging and Radiotherapy, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | | | - A Rosato
- Istituto Oncologico Veneto IRCCS, Padova, Italy; Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - M Colombatti
- Department of Pathology and Diagnostics, Section of Immunology, University of Verona, Verona, Italy
| | - S Canevari
- Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - M Figini
- Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy.
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