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Karachaliou CE, Kostopoulos IV, Vassilakopoulou V, Klimentzou P, Paravatou-Petsotas M, Voelter W, Kalbacher H, Zikos C, Tsitsilonis O, Livaniou E. Development of a specific IgY-based ELISA for prothymosin alpha, a bioactive polypeptide with diagnostic and therapeutic potential. Heliyon 2019; 5:e02616. [PMID: 31720448 PMCID: PMC6838902 DOI: 10.1016/j.heliyon.2019.e02616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 09/10/2019] [Accepted: 10/04/2019] [Indexed: 01/15/2023] Open
Abstract
Prothymosin alpha (ProTα) is a highly conserved polypeptide (109 amino acids in humans) with diagnostic and therapeutic potential; ProTα exerts intra- and extra-cellular biological functions associated with cell proliferation, apoptosis and immune regulation, while it has been suggested to act as a damage-associated molecular pattern (DAMP) or alarmin. In this work, chicken polyclonal anti-ProTα antibodies that had been developed several years ago were immunochemically evaluated and proven to retain immunoreactivity for ProTα, with remarkable thermal and pH stability. Moreover, the antibodies showed practically no cross-reactivity with a series of ProTα-fragments, eventually intracellularly produced -such as ProTα[1-28] (also known as Tα1) and ProTα[100-109], which exert per se biological activity and might be present in biological samples along with the intact molecule, being therefore highly specific for whole-length ProTα. Based on the above antibodies (IgYs-3e), a highly specific competitive ProTα-ELISA with well-studied analytical characteristics (intra- and inter-assay CVs: ≤5% and ≤12%, respectively, limit of detection: 2.1 ng/mL, recovery: 88–104%) was developed. The new ProTα-ELISA was applied to the analysis of supernatants of HeLa cells driven to necrosis; intact ProTα was measured in cell culture supernatants, at levels that seemed to depend on % cell necrosis.
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Affiliation(s)
- Chrysoula-Evangelia Karachaliou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Ioannis V Kostopoulos
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Vyronia Vassilakopoulou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Persefoni Klimentzou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Maria Paravatou-Petsotas
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Wolfgang Voelter
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen, Germany
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen, Germany
| | - Christos Zikos
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Ourania Tsitsilonis
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelia Livaniou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", Athens, Greece
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Karachaliou CE, Triantis C, Liolios C, Palamaris L, Zikos C, Tsitsilonis OE, Kalbacher H, Voelter W, Loudos G, Papadopoulos M, Pirmettis I, Livaniou E. In vivo biodistribution and imaging studies with a 99mTc-radiolabeled derivative of the C-terminus of prothymosin alpha in mice bearing experimentally-induced inflammation. Eur J Pharm Biopharm 2017; 113:188-197. [PMID: 28087377 DOI: 10.1016/j.ejpb.2016.12.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/15/2016] [Accepted: 12/14/2016] [Indexed: 10/20/2022]
Abstract
Prothymosin alpha (ProTα) is a highly conserved mammalian polypeptide (109 amino acids in man) exerting in vitro and in vivo immunoenhancing activities. Recently, our team has developed a 99mTc-radiolabeled derivative of the C-terminal bioactive decapeptide of ProTα ([99mTc]C1) and employed it in in vitro studies, the results of which support the existence of binding sites on human neutrophils that recognize [99mTc]C1, intact ProTα as well as the C-terminal decapeptide of ProTα and presumably involve Toll-like receptor 4. In the present work, [99mTc]C1 was administered to Swiss albino mice with experimentally-induced inflammation for in vivo biodistribution and imaging studies, in parallel with a suitable negative control, which differs from [99mTc]C1 only in bearing a scrambled version of the ProTα decapeptide. The biodistribution data obtained with [99mTc]C1 demonstrated fast clearance of radioactivity from blood, heart, lungs, normal muscle, and predominantly urinary excretion. Most importantly, slow clearance of radioactivity from the inflammation focus was observed, resulting in a high ratio of inflamed/normal muscle tissue (9.15 at 30min post injection, which remained practically stable up to 2h). The inflammation-targeting capacity of [99mTc]C1 was confirmed by imaging studies and might be attributed to neutrophils, which are recruited at the inflamed areas and bear binding sites for [99mTc]C1. In this respect, apart from being a valuable tool for further studies on ProTα in in vitro and in vivo systems, [99mTc]C1 merits further evaluation as a radiopharmaceutical for specific imaging of inflammation foci.
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Affiliation(s)
- Chrysoula-Evangelia Karachaliou
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Charalampos Triantis
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Christos Liolios
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Lazaros Palamaris
- Department of Medical Instruments Technology, Technological Educational Institute, Athens 12243, Greece
| | - Christos Zikos
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Ourania E Tsitsilonis
- Division of Animal and Human Physiology, Department of Biology, University of Athens, Athens 15784, Greece
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen 72076, Germany
| | - Wolfgang Voelter
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen 72076, Germany
| | - George Loudos
- Department of Medical Instruments Technology, Technological Educational Institute, Athens 12243, Greece
| | - Minas Papadopoulos
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Ioannis Pirmettis
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece
| | - Evangelia Livaniou
- Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety (INRASTES), National Center for Scientific Research "Demokritos" (NCSR "Demokritos"), Athens 15310, Greece.
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Karachaliou CE, Liolios C, Triantis C, Zikos C, Samara P, Tsitsilonis OE, Kalbacher H, Voelter W, Papadopoulos M, Pirmettis I, Livaniou E. Specific in vitro binding of a new (99m)Tc-radiolabeled derivative of the C-terminal decapeptide of prothymosin alpha on human neutrophils. Int J Pharm 2015; 486:1-12. [PMID: 25796124 DOI: 10.1016/j.ijpharm.2015.03.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/13/2015] [Accepted: 03/16/2015] [Indexed: 11/28/2022]
Abstract
Prothymosin alpha (ProTα) is a conserved mammalian polypeptide with intracellular functions associated with cell proliferation and apoptosis and an extracellular role associated with immunopotentiation. The N-terminal fragment [1-28], which is identical with the immunostimulating peptide thymosin α1 (Tα1), was earlier considered as the immunoactive region of the polypeptide; however, recent data suggest that ProTα may exert a discrete immunomodulating action through its central or C-terminal region, via targeting Toll-like receptor- 4 (TLR4). In this work, a derivative of the C-terminal fragment ProTα[100-109] (ProTα-D1) that can be radiolabeled with (99m)Tc was developed. The biological activity of the non-radioactive (185/187)rhenium-complex of this derivative ([(185/187)Re]ProTα-D1, structurally similar with [(99m)Tc]ProTα-D1) was verified through suitable in vitro bioassays on human neutrophils. Subsequent cell-binding studies revealed specific, time-dependent and saturable binding of [(99m)Tc]ProTα-D1 on neutrophils, which was inhibited by intact ProTα and ProTα[100-109], as well as by a "prototype" TLR4-ligand (lipopolysaccharide from Escherichia coli). Overall, our results support the existence of ProTα-binding sites on human neutrophils, recognizing [(99m)Tc]ProTα-D1, which might involve TLR4. [(99m)Tc]ProTα-D1 may be a useful tool for conducting further in vitro and in vivo studies, aiming to elucidate the extracellular mode of action of ProTα and, eventually, develop ProTα-based immunotherapeutics.
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Affiliation(s)
- Chrysoula-Evangelia Karachaliou
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Christos Liolios
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Charalampos Triantis
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Christos Zikos
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Pinelopi Samara
- Faculty of Biology, University of Athens, Athens 15784, Greece
| | | | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen 72076, Germany
| | - Wolfgang Voelter
- Interfaculty Institute of Biochemistry, University of Tuebingen, Tuebingen 72076, Germany
| | - Minas Papadopoulos
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Ioannis Pirmettis
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece
| | - Evangelia Livaniou
- Institute of Nuclear and Radiological Sciences & Technology, Energy and Safety (INRaSTES), National Center for Scientific Research "Demokritos", Athens 15310, Greece.
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Benaki D, Zikos C, Karachaliou CE, Tsitsilonis O, Leondiadis L, Kalbacher H, Voelter W, Papadopoulos M, Pirmettis I, Pelecanou M, Livaniou E. Complexes of an Alpha Thymosin Derivative with185/187Re and99mTc: Structural Analysis and Initial Biological Evaluation. Chem Biol Drug Des 2012; 80:545-53. [DOI: 10.1111/j.1747-0285.2012.01425.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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García-Ramos Y, Giraud M, Tulla-Puche J, Albericio F. Optimized Fmoc solid-phase synthesis of Thymosin alpha1 by side-chain anchoring onto a PEG resin. Biopolymers 2010; 92:565-72. [PMID: 19802821 DOI: 10.1002/bip.21317] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Thymosin alpha1 is a 28-amino acid acetylated peptide used for the treatment of hepatitis B and C. This peptide has a difficult sequence because of the presence of consecutive beta-branched amino acids and shows a tendency to form beta-sheet structures, partly as a result of the many protecting groups required to assemble the peptide (up to 20 side-chain protecting groups). Consequently, its synthesis has been generally achieved by convergent solution chemistry. Here we report a straightforward stepwise solid-phase synthesis on a polyethylene glycol solid-support that enables the scaling-up of this key therapeutic peptide.
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Affiliation(s)
- Yésica García-Ramos
- Institute for Research in Biomedicine, Barcelona Science Park, Baldiri Reixac 10, 08028-Barcelona, Spain
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