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Wang Y, Lindstam M, Hwang D, Jedlina L, Liu M. Therapeutic Effects of a Novel Aptamer on Coronaviral Infection-Induced Lung Injury and Systemic Inflammatory Responses. Cells 2024; 13:422. [PMID: 38474386 DOI: 10.3390/cells13050422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/08/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND Coronaviral infection-induced acute lung injury has become a major threat to public health, especially through the ongoing pandemic of COVID-19. Apta-1 is a newly discovered Aptamer that has anti-inflammatory effects on systemic septic responses. The therapeutic effects of Apta-1 on coronaviral infection-induced acute lung injury and systemic responses were evaluated in the present study. METHODS Female A/J mice (at 12-14 weeks of age) were challenged with murine hepatitis virus 1 (MHV-1), a coronavirus, at 5000 PFU intranasally, followed by Apta-1 intravenously administered (100 mg/kg, twice) 1.5 h or 2 days after viral delivery. Animals were sacrificed at Day 2 or Day 4. Lung tissues were examined with H&E, immunohistochemistry staining, and western blotting. RT-qPCR was used for cytokine gene expression. Serum and plasma were collected for laboratory assessments. RESULTS Apta-1 treatment reduced viral titers, prevented MHV-1-induced reduction of circulating blood volume and hemolysis, reduced alveolar space hemorrhage, and protease-activated receptor 1 (PAR-1) cleavage. Apta-1 treatment also significantly reduced chemokine (MKC, MCP-1, and RANTES) levels, as well as AST, ALT, total bilirubin, and reduced unconjugated bilirubin levels in the serum. CONCLUSION Apta-1 showed therapeutic benefits in coronaviral infection-induced hemorrhage and PAR-1 cleavage in the lung. It also has anti-inflammatory effects systemically.
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Affiliation(s)
- Yingchun Wang
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 1L7, Canada
| | | | - David Hwang
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | | | - Mingyao Liu
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto, ON M5G 1L7, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Departments of Surgery, Medicine, and Physiology, Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
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2
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Selection of an Aptamer against the Enzyme 1-deoxy-D-xylulose-5-phosphate Reductoisomerase from Plasmodium falciparum. Pharmaceutics 2022; 14:pharmaceutics14112515. [PMID: 36432706 PMCID: PMC9695703 DOI: 10.3390/pharmaceutics14112515] [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: 09/14/2022] [Revised: 11/03/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
The methyl erythritol phosphate (MEP) pathway of isoprenoid biosynthesis is essential for malaria parasites and also for several human pathogenic bacteria, thus representing an interesting target for future antimalarials and antibiotics and for diagnostic strategies. We have developed a DNA aptamer (D10) against Plasmodium falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), the second enzyme of this metabolic route. D10 binds in vitro to recombinant DXR from P. falciparum and Escherichia coli, showing at 10 µM a ca. 50% inhibition of the bacterial enzyme. In silico docking analysis indicates that D10 associates with DXR in solvent-exposed regions outside the active center pocket. According to fluorescence confocal microscopy data, this aptamer specifically targets in P. falciparum in vitro cultures the apicoplast organelle where the MEP pathway is localized and is, therefore, a highly specific marker of red blood cells parasitized by Plasmodium vs. naïve erythrocytes. D10 is also selective for the detection of MEP+ bacteria (e.g., E. coli and Pseudomonas aeruginosa) vs. those lacking DXR (e.g., Enterococcus faecalis). Based on these results, we discuss the potential of DNA aptamers in the development of ligands that can outcompete the performance of the well-established antibody technology for future therapeutic and diagnostic approaches.
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3
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Gan Z, Roslan MAM, Abd Shukor MY, Halim M, Yasid NA, Abdullah J, Md Yasin IS, Wasoh H. Advances in Aptamer-Based Biosensors and Cell-Internalizing SELEX Technology for Diagnostic and Therapeutic Application. BIOSENSORS 2022; 12:bios12110922. [PMID: 36354431 PMCID: PMC9687594 DOI: 10.3390/bios12110922] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 05/28/2023]
Abstract
Aptamers are a group of synthetic single-stranded nucleic acids. They are generated from a random library of single-stranded DNA or RNA by a technology named systematic evolution of ligands by exponential enrichment (SELEX). SELEX is a repetitive process to select and identify suitable aptamers that show high affinity and specificity towards target cells. Great strides have been achieved in the design, construction, and use of aptamers up to this point. However, only a small number of aptamer-based applications have achieved widespread commercial and clinical acceptance. Additionally, finding more effective ways to acquire aptamers with high affinity remains a challenge. Therefore, it is crucial to thoroughly examine the existing dearth and advancement in aptamer-related technologies. This review focuses on aptamers that are generated by SELEX to detect pathogenic microorganisms and mammalian cells, as well as in cell-internalizing SELEX for diagnostic and therapeutic purposes. The development of novel aptamer-based biosensors using optical and electrical methods for microbial detection is reported. The applications and limitations of aptamers are also discussed.
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Affiliation(s)
- Zixuen Gan
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | | | - Mohd Yunus Abd Shukor
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | - Murni Halim
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | - Nur Adeela Yasid
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | - Jaafar Abdullah
- Faculty of Science, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | - Ina Salwany Md Yasin
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
| | - Helmi Wasoh
- Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
- Halal Products Research Institute, Universiti Putra Malaysia, Serdang 43400, SGR, Malaysia
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4
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Navien TN, Yeoh TS, Anna A, Tang TH, Citartan M. Aptamers isolated against mosquito-borne pathogens. World J Microbiol Biotechnol 2021; 37:131. [PMID: 34240263 DOI: 10.1007/s11274-021-03097-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/21/2021] [Indexed: 11/27/2022]
Abstract
Mosquito-borne diseases are a major threat to public health. The shortcomings of diagnostic tools, especially those that are antibody-based, have been blamed in part for the rising annual morbidity and mortality caused by these diseases. Antibodies harbor a number of disadvantages that can be clearly addressed by aptamers as the more promising molecular recognition elements. Aptamers are defined as single-stranded DNA or RNA oligonucleotides generated by SELEX that exhibit high binding affinity and specificity against a wide variety of target molecules based on their unique structural conformations. A number of aptamers were developed against mosquito-borne pathogens such as Dengue virus, Zika virus, Chikungunya virus, Plasmodium parasite, Francisella tularensis, Japanese encephalitis virus, Venezuelan equine encephalitis virus, Rift Valley fever virus and Yellow fever virus. Intrigued by these achievements, we carry out a comprehensive overview of the aptamers developed against these mosquito-borne infectious agents. Characteristics of the aptamers and their roles in diagnostic, therapeutic as well as other applications are emphasized.
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Affiliation(s)
- Tholasi Nadhan Navien
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
| | - Tzi Shien Yeoh
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
| | - Andrew Anna
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak (UNIMAS), 94300, Kota Samarahan, Sarawak, Malaysia
| | - Thean-Hock Tang
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
| | - Marimuthu Citartan
- Advanced Medical & Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
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Allemailem KS, Almatroudi A, Alsahli MA, Basfar GT, Alrumaihi F, Rahmani AH, Khan AA. Recent advances in understanding oligonucleotide aptamers and their applications as therapeutic agents. 3 Biotech 2020; 10:551. [PMID: 33269185 PMCID: PMC7686427 DOI: 10.1007/s13205-020-02546-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 11/06/2020] [Indexed: 12/12/2022] Open
Abstract
The innovative discovery of aptamers was based on target-specific treatment in clinical diagnostics and therapeutics. Aptamers are synthetic, single-stranded oligonucleotides, simply described as chemical antibodies, which can bind to diverse targets with high specificity and affinity. Aptamers are synthesized by the SELEX technique, and possess distinctive properties as small size (10-50 kDa), higher stability, easy manufacture and less immunogenicity. These oligonucleotides are easily degraded by nucleases, so require some important modifications like capping and incorporation of modified nucleotides. RNA aptamers can be modified chemically on 2' positions using -NH3, -F, -deoxy, or -OMe groups to enhance their nuclease resistance. Aptamers have been employed for multiple purposes, as direct drugs or aptamer-drug conjugates targeted against different diseased cells. Different aptamer-conjugated nanovehicles (e.g., micelles, liposomes, silica nano-shells) have been designed to transport diverse anticancer-drugs like doxorubicin and cisplatin in bulk to minimize systemic cytotoxicity. Some drug-loaded nanovehicles (up to 97% loading capacity) and conjugated with specific aptamer resulted in more than 60% tumor inhibition as compared to unconjugated drug-loaded nanovehicles which showed only 31% cancer inhibition. In addition, aptamers have been widely used in basic research, food safety, environmental monitoring, clinical diagnostics and therapeutics. Different FDA-approved RNA and DNA aptamers are now available in the market, used for the treatment of diverse diseases, especially cancer. These aptamers include Macugen, Pegaptanib, etc. Despite a good progress in aptamer use, the present-day chemotherapeutics and drug targeting systems still face great challenges. Here in this review article, we are discussing nucleic acid aptamers, preparation, role in the transportation of different nanoparticle vehicles and their applications as therapeutic agents.
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Affiliation(s)
- Khaled S. Allemailem
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
- Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, P.O. Box 6699, Buraydah, 51452 Saudi Arabia
| | - Ahmad Almatroudi
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
| | - Mohammed A. Alsahli
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
| | - Ghaiyda Talal Basfar
- Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Faris Alrumaihi
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
| | - Arshad Husain Rahmani
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
| | - Amjad Ali Khan
- Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, P.O. Box 6699, Buraydah, 51452 Saudi Arabia
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6
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Oteng EK, Gu W, McKeague M. High-efficiency enrichment enables identification of aptamers to circulating Plasmodium falciparum-infected erythrocytes. Sci Rep 2020; 10:9706. [PMID: 32546848 PMCID: PMC7298056 DOI: 10.1038/s41598-020-66537-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 05/04/2020] [Indexed: 01/08/2023] Open
Abstract
Plasmodium falciparum is the causative agent of the deadliest human malaria. New molecules are needed that can specifically bind to erythrocytes that are infected with P. falciparum for diagnostic purposes, to disrupt host-parasite interactions, or to deliver chemotherapeutics. Aptamer technology has the potential to revolutionize biological diagnostics and therapeutics; however, broad adoption is hindered by the high failure rate of the systematic evolution of ligands by exponential enrichment (SELEX). Here we performed parallel SELEX experiments to compare the impact of two different methods for single-strand recovery on the efficiency of aptamer enrichment. Our experimental results and analysis of SELEX publications spanning 13 years implicate the alkaline denaturation step as a significant cause for inefficient aptamer selection. Thus, we applied an exonuclease single-strand recovery step in our SELEX to direct aptamers to the surface of erythrocytes infected with P. falciparum. The selected aptamers bind with high affinity (low nanomolar Kd values) and selectivity to exposed surface proteins of both laboratory parasite strains as well isolates from patients in Asia and Africa with clinical malaria. The results obtained in this study potentially open new approaches to malaria diagnosis and surveillance.
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Affiliation(s)
- Eugene K Oteng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, 20852, USA.
| | - Wenjuan Gu
- Clinical Research Directorate/Clinical Monitoring Research Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, 21702, USA
| | - Maureen McKeague
- Department of Pharmacology and Therapeutics, McGill University, 3655 Prom. Sir-William-Osler, Montreal, Quebec, H3G 1Y6, Canada.,Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
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Aptamers as a novel diagnostic and therapeutic tool and their potential use in parasitology. ACTA ACUST UNITED AC 2020; 40:148-165. [PMID: 32463617 PMCID: PMC7449109 DOI: 10.7705/biomedica.4765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Indexed: 02/07/2023]
Abstract
Los aptámeros son secuencias de ADN o ARN de cadena sencilla que adoptan la forma de estructuras tridimensionales únicas, lo cual les permite reconocer un blanco específico con gran afinidad. Sus usos potenciales abarcan, entre otros, el diagnóstico de enfermedades, el desarrollo de nuevos agentes terapéuticos, la detección de riesgos alimentarios, la producción de biosensores, la detección de toxinas, el transporte de fármacos en el organismo y la señalización de nanopartículas. El pegaptanib es el único aptámero aprobado para uso comercial por la Food and Drug Administration (FDA). Otros aptámeros para el tratamiento de enfermedades están en la fase clínica de desarrollo. En parasitología, se destacan los estudios que se vienen realizando en Leishmania spp., con la obtención de aptámeros que reconocen la proteína de unión a poliA (LiPABP) y que pueden tener potencial utilidad en la investigación, el diagnóstico y el tratamiento de la leishmaniasis. En cuanto a la malaria, se han obtenido aptámeros que permiten identificar eritrocitos infectados e inhiben la formación de rosetas, y otros que prometen ser alternativas para el diagnóstico al detectar de forma específica la proteína lactato deshidrogenasa (PfLDH). Para Cryptosporidium parvuum se han seleccionado aptámeros que detectan ooquistes a partir de alimentos o aguas contaminadas. Para Entamoeba histolytica se han aislado dos aptámeros llamados C4 y C5, que inhiben la proliferación in vitro de los trofozoítos y tienen potencial terapéutico. Los aptámeros contra Trypanosoma cruzi inhiben la invasión de células LLC-MK2 (de riñón de mono) en un 50 a 70 % y aquellos contra T. brucei transportan moléculas tóxicas al lisosoma parasitario como una novedosa estrategia terapéutica. Los datos recopilados en esta revisión destacan los aptámeros como una alternativa para la investigación, el diagnóstico y el tratamiento contra parásitos de interés nacional.
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Batista FA, Gyau B, Vilacha JF, Bosch SS, Lunev S, Wrenger C, Groves MR. New directions in antimalarial target validation. Expert Opin Drug Discov 2020; 15:189-202. [PMID: 31959021 DOI: 10.1080/17460441.2020.1691996] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Introduction: Malaria is one of the most prevalent human infections worldwide with over 40% of the world's population living in malaria-endemic areas. In the absence of an effective vaccine, emergence of drug-resistant strains requires urgent drug development. Current methods applied to drug target validation, a crucial step in drug discovery, possess limitations in malaria. These constraints require the development of techniques capable of simplifying the validation of Plasmodial targets.Areas covered: The authors review the current state of the art in techniques used to validate drug targets in malaria, including our contribution - the protein interference assay (PIA) - as an additional tool in rapid in vivo target validation.Expert opinion: Each technique in this review has advantages and disadvantages, implying that future validation efforts should not focus on a single approach, but integrate multiple approaches. PIA is a significant addition to the current toolset of antimalarial validation. Validation of aspartate metabolism as a druggable pathway provided proof of concept of how oligomeric interfaces can be exploited to control specific activity in vivo. PIA has the potential to be applied not only to other enzymes/pathways of the malaria parasite but could, in principle, be extrapolated to other infectious diseases.
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Affiliation(s)
- Fernando A Batista
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.,Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Benjamin Gyau
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Juliana F Vilacha
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Soraya S Bosch
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands.,Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sergey Lunev
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Matthew R Groves
- Structural Biology Unit, XB20 Drug Design, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
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Afrasiabi S, Pourhajibagher M, Raoofian R, Tabarzad M, Bahador A. Therapeutic applications of nucleic acid aptamers in microbial infections. J Biomed Sci 2020; 27:6. [PMID: 31900238 PMCID: PMC6941257 DOI: 10.1186/s12929-019-0611-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/19/2019] [Indexed: 02/07/2023] Open
Abstract
Today, the treatment of bacterial infections is a major challenge, due to growing rate of multidrug-resistant bacteria, complication of treatment and increased healthcare costs. Moreover, new treatments for bacterial infections are limited. Oligonucleotide aptamers are single stranded DNAs or RNAs with target-selective high-affinity feature, which considered as nucleic acid-based affinity ligands, replacing monoclonal antibodies. The aptamer-based systems have been found to be talented tools in the treatment of microbial infections, regarding their promising anti-biofilm and antimicrobial activities; they can reduce or inhibit the effects of bacterial toxins, and inhibit pathogen invasion to immune cell, as well as they can be used in drug delivery systems. The focus of this review is on the therapeutic applications of aptamers in infections. In this regard, an introduction of infections and related challenges were presented, first. Then, aptamer definition and selection, with a brief history of aptamers development against various pathogens and toxins were reviewed. Diverse strategies of aptamer application in drug delivery, as well as, the effect of aptamers on the immune system, as the main natural agents of human defense against pathogens, were also discussed. Finally, the future trends in clinical applications of this technology were discussed.
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Affiliation(s)
- Shima Afrasiabi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Pourhajibagher
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Raoofian
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | - Maryam Tabarzad
- Protein Technology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Abbas Bahador
- Oral Microbiology Laboratory, Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Gitta B, Kilian N. Diagnosis of Malaria Parasites Plasmodium spp. in Endemic Areas: Current Strategies for an Ancient Disease. Bioessays 2019; 42:e1900138. [PMID: 31830324 DOI: 10.1002/bies.201900138] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/05/2019] [Indexed: 12/14/2022]
Abstract
Fast and effective detection of the causative agent of malaria in humans, protozoan Plasmodium parasites, is of crucial importance for increasing the effectiveness of treatment and to control a devastating disease that affects millions of people living in endemic areas. The microscopic examination of Giemsa-stained blood films still remains the gold-standard in Plasmodium detection today. However, there is a high demand for alternative diagnostic methods that are simple, fast, highly sensitive, ideally do not rely on blood-drawing and can potentially be conducted by the patients themselves. Here, the history of Plasmodium detection is discussed, and advantages and disadvantages of diagnostic methods that are currently being applied are assessed.
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Affiliation(s)
- Brian Gitta
- Matibabu, 120 Semawata Rd, Ntinda, Kampala, 00256, Uganda
| | - Nicole Kilian
- Centre for Infectious Diseases, Parasitology Heidelberg University Hospital, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
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Linzke M, Yan SLR, Tárnok A, Ulrich H, Groves MR, Wrenger C. Live and Let Dye: Visualizing the Cellular Compartments of the Malaria Parasite Plasmodium falciparum. Cytometry A 2019; 97:694-705. [PMID: 31738009 DOI: 10.1002/cyto.a.23927] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 10/03/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022]
Abstract
Malaria remains one of the deadliest diseases worldwide and it is caused by the protozoan parasite Plasmodium spp. Parasite visualization is an important tool for the correct detection of malarial cases but also to understand its biology. Advances in visualization techniques promote new insights into the complex life cycle and biology of Plasmodium parasites. Live cell imaging by fluorescence microscopy or flow cytometry are the foundation of the visualization technique for malaria research. In this review, we present an overview of possibilities in live cell imaging of the malaria parasite. We discuss some of the state-of-the-art techniques to visualize organelles and processes of the parasite and discuss limitation and advantages of each technique. © 2019 International Society for Advancement of Cytometry.
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Affiliation(s)
- Marleen Linzke
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
| | - Sun Liu Rei Yan
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
| | - Attila Tárnok
- Institute for Medical Informatics, Statistics and Epidemiology, Medical Faculty, University Leipzig, D-04107, Härtelstraße 16-18, Leipzig, Germany
| | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Avenida Professor Lineu Prestes 748, São Paulo, São Paulo, 05508-900, Brazil
| | - Matthew R Groves
- Structural Biology Unit, Department of Pharmacy, Faculty of Science and Engineering, University of Groningen, 9713AV, Antonius Deusinglaan 1, AV Groningen, The Netherlands
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes 1374, São Paulo, São Paulo, 05508-000, Brazil
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Abstract
This chapter provides a brief introduction to followed by discussion of recent preclinical studies on potential aptamer drugs grouped into two broad categories, namely, “aptamer structures” and “non-ocular diseases.” Examples of aptamer-based targeting of drugs are then described. Next is an overview of the status of nearly 30 clinical trials of aptamer drugs currently listed in ClinicalTrials.gov, which is a registry and results database of publicly and privately supported clinical studies of human participants conducted around the world, and is a service of the US National Institutes of Health. This overview includes brief descriptions of each study sponsor, aptamer drug, disease(s), and type of study, as well as separate tables for completed studies, withdrawn or terminated studies, and active studies. The final section discusses Conclusions and Prospects.
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Affiliation(s)
- G. Zon
- TriLink BioTechnologies 9955 Mesa Rim Road San Diego 92121 USA
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13
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Advances on Aptamers against Protozoan Parasites. Genes (Basel) 2018; 9:genes9120584. [PMID: 30487456 PMCID: PMC6316487 DOI: 10.3390/genes9120584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/16/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023] Open
Abstract
Aptamers are single-stranded DNA or RNA sequences with a unique three-dimensional structure that allows them to recognize a particular target with high affinity. Although their specific recognition activity could make them similar to monoclonal antibodies, their ability to bind to a large range of non-immunogenic targets greatly expands their potential as tools for diagnosis, therapeutic agents, detection of food risks, biosensors, detection of toxins, drug carriers, and nanoparticle markers, among others. One aptamer named Pegaptanib is currently used for treating macular degeneration associated with age, and many other aptamers are in different clinical stages of development of evaluation for various human diseases. In the area of parasitology, research on aptamers has been growing rapidly in the past few years. Here we describe the development of aptamers raised against the main protozoan parasites that affect hundreds of millions of people in underdeveloped and developing countries, remaining a major health concern worldwide, i.e. Trypanosoma spp., Plasmodium spp., Leishmania spp., Entamoeba histolytica, and Cryptosporidium parvuum. The latest progress made in this area confirmed that DNA and RNA aptamers represent attractive alternative molecules in the search for new tools to detect and treat these parasitic infections that affect human health worldwide.
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Sekhon SS, Ahn G, Sekhon SS, Ahn JY, Kim YH. Bioengineered aptamer-nanoconjugates for cancer theragnosis. Mol Cell Toxicol 2018. [DOI: 10.1007/s13273-018-0040-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Nik Kamarudin NAA, Mohammed NA, Mustaffa KMF. Aptamer Technology: Adjunct Therapy for Malaria. Biomedicines 2017; 5:biomedicines5010001. [PMID: 28536344 PMCID: PMC5423489 DOI: 10.3390/biomedicines5010001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/08/2016] [Accepted: 12/16/2016] [Indexed: 02/07/2023] Open
Abstract
Malaria is a life-threatening parasitic infection occurring in the endemic areas, primarily in children under the age of five, pregnant women, and patients with human immunodeficiency virus and acquired immunodeficiency syndrome (HIV)/(AIDS) as well as non-immune individuals. The cytoadherence of infected erythrocytes (IEs) to the host endothelial surface receptor is a known factor that contributes to the increased prevalence of severe malaria cases due to the accumulation of IEs, mainly in the brain and other vital organs. Therefore, further study is needed to discover a new potential anti-adhesive drug to treat severe malaria thus reducing its mortality rate. In this review, we discuss how the aptamer technology could be applied in the development of a new adjunct therapy for current malaria treatment.
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Affiliation(s)
- Nik Abdul Aziz Nik Kamarudin
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Health Campus, Kubang Kerian, 16150 Kelantan, Malaysia.
| | - Nurul Adila Mohammed
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Health Campus, Kubang Kerian, 16150 Kelantan, Malaysia.
| | - Khairul Mohd Fadzli Mustaffa
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Health Campus, Kubang Kerian, 16150 Kelantan, Malaysia.
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Ospina-Villa JD, Zamorano-Carrillo A, Castañón-Sánchez CA, Ramírez-Moreno E, Marchat LA. Aptamers as a promising approach for the control of parasitic diseases. Braz J Infect Dis 2016; 20:610-618. [PMID: 27755981 PMCID: PMC9427573 DOI: 10.1016/j.bjid.2016.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/15/2016] [Accepted: 08/16/2016] [Indexed: 01/31/2023] Open
Abstract
Aptamers are short single-stranded RNA or DNA oligonucleotides that are capable of binding various biological targets with high affinity and specificity. Their identification initially relies on a molecular process named SELEX (Systematic Evolution of Ligands by EXponential enrichment) that has been later modified in order to improve aptamer sensitivity, minimize duration and cost of the assay, as well as increase target types. Several biochemical modifications can help to enhance aptamer stability without affecting significantly target interaction. As a result, aptamers have generated a large interest as promising tools to compete with monoclonal antibodies for detection and inhibition of specific markers of human diseases. One aptamer-based drug is currently authorized and several others are being clinically evaluated. Despite advances in the knowledge of parasite biology and host–parasite interactions from “omics” data, protozoan parasites still affect millions of people around the world and there is an urgent need for drug target discovery and novel therapeutic concepts. In this context, aptamers represent promising tools for pathogen identification and control. Recent studies have reported the identification of “aptasensors” for parasite diagnosis, and “intramers” targeting intracellular proteins. Here we discuss various strategies that have been employed for intracellular expression of aptamers and expansion of their possible application, and propose that they may be suitable for the clinical use of aptamers in parasitic infections.
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Affiliation(s)
- Juan David Ospina-Villa
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Ciudad de Mexico, Mexico
| | | | - Carlos A Castañón-Sánchez
- Hospital Regional de Alta Especialidad de Oaxaca, Subdirección de Enseñanza e Investigación, Oaxaca, Mexico
| | - Esther Ramírez-Moreno
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Ciudad de Mexico, Mexico
| | - Laurence A Marchat
- Instituto Politécnico Nacional, Escuela Nacional de Medicina y Homeopatía, Ciudad de Mexico, Mexico.
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Zhang H, Zhou L, Zhu Z, Yang C. Recent Progress in Aptamer-Based Functional Probes for Bioanalysis and Biomedicine. Chemistry 2016; 22:9886-900. [PMID: 27243551 DOI: 10.1002/chem.201503543] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 02/16/2016] [Indexed: 01/01/2023]
Abstract
Nucleic acid aptamers are short synthetic DNA or RNA sequences that can bind to a wide range of targets with high affinity and specificity. In recent years, aptamers have attracted increasing research interest due to their unique features of high binding affinity and specificity, small size, excellent chemical stability, easy chemical synthesis, facile modification, and minimal immunogenicity. These properties make aptamers ideal recognition ligands for bioanalysis, disease diagnosis, and cancer therapy. This review highlights the recent progress in aptamer selection and the latest applications of aptamer-based functional probes in the fields of bioanalysis and biomedicine.
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Affiliation(s)
- Huimin Zhang
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Leiji Zhou
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Zhi Zhu
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Chaoyong Yang
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
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Hora R, Kapoor P, Thind KK, Mishra PC. Cerebral malaria--clinical manifestations and pathogenesis. Metab Brain Dis 2016; 31:225-37. [PMID: 26746434 DOI: 10.1007/s11011-015-9787-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 12/22/2015] [Indexed: 01/28/2023]
Abstract
One of the most common central nervous system diseases in tropical countries is cerebral malaria (CM). Malaria is a common protozoan infection that is responsible for enormous worldwide mortality and economic burden on the society. Episodes of Plasmodium falciparum (Pf) caused CM may be lethal, while survivors are likely to suffer from persistent debilitating neurological deficits, especially common in children. In this review article, we have summarized the various symptoms and manifestations of CM in children and adults, and entailed the molecular basis of the disease. We have also emphasized how pathogenesis of the disease is effected by the parasite and host responses including blood brain barrier (BBB) disruption, endothelial cell activation and apoptosis, nitric oxide bioavailability, platelet activation and apoptosis, and neuroinflammation. Based on a few recent studies carried out in experimental mouse malaria models, we propose a basis for the neurological deficits and sequelae observed in human cerebral malaria, and summarize how existing drugs may improve prognosis in affected individuals.
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Affiliation(s)
- Rachna Hora
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005, India.
| | - Payal Kapoor
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005, India
| | - Kirandeep Kaur Thind
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, 143005, India
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Barfod A, Singh B, Johanson U, Riesbeck K, Kjellbom P. In vitro selection of RNA aptamers directed against protein E: a Haemophilus influenzae adhesin. Mol Biotechnol 2015; 56:714-25. [PMID: 24682699 DOI: 10.1007/s12033-014-9749-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein E (PE) of Haemophilus influenzae is a highly conserved ubiquitous surface protein involved in adhesion to and activation of epithelial cells. The host proteins-vitronectin, laminin, and plasminogen are major targets for PE-dependent interactions with the host. To identify novel inhibitory molecules of PE, we used an in vitro selection method based on systematic evolution of ligands by exponential enrichment known as SELEX in order to select 2'F-modified RNA aptamers that specifically bind to PE. Fourteen selection cycles were performed with decreasing concentrations of PE. Sequencing of clones from the 14th selection round revealed the presence of semiconserved sequence motifs in loop regions of the RNA aptamers. Among these, three aptamers showed the highest affinity to PE in electrophoretic mobility shift assays and in dot blots. These three aptamers also inhibited the interaction of PE with vitronectin as revealed by ELISA. Moreover, pre-treatment of H. influenzae with the aptamers significantly inhibited binding of vitronectin to the bacterial surface. Biacore experiments indicated that one of the aptamers had a higher binding affinity for PE as compared to the other aptamers. Our results show that it is possible to select RNA inhibitors against bacterial adhesins using SELEX in order to inhibit interactions with target proteins.
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Affiliation(s)
- Anders Barfod
- Department of Biochemistry and Structural Biology, CMPS, Lund University, Box 124, 221 00, Lund, Sweden,
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Davydova A, Vorobjeva M, Pyshnyi D, Altman S, Vlassov V, Venyaminova A. Aptamers against pathogenic microorganisms. Crit Rev Microbiol 2015; 42:847-65. [PMID: 26258445 PMCID: PMC5022137 DOI: 10.3109/1040841x.2015.1070115] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
An important current issue of modern molecular medicine and biotechnology is the search for new approaches to early diagnostic assays and adequate therapy of infectious diseases. One of the promising solutions to this problem might be a development of nucleic acid aptamers capable of interacting specifically with bacteria, protozoa, and viruses. Such aptamers can be used for the specific recognition of infectious agents as well as for blocking of their functions. The present review summarizes various modern SELEX techniques used in this field, and of several currently identified aptamers against viral particles and unicellular organisms, and their applications. The prospects of applying nucleic acid aptamers for the development of novel detection systems and antibacterial and antiviral drugs are discussed.
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Affiliation(s)
- Anna Davydova
- a Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences , Novosibirsk , Russia and
| | - Maria Vorobjeva
- a Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences , Novosibirsk , Russia and
| | - Dmitrii Pyshnyi
- a Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences , Novosibirsk , Russia and
| | - Sidney Altman
- b Department of Molecular, Cellular and Developmental Biology , Yale University , New Haven , CT , USA
| | - Valentin Vlassov
- a Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences , Novosibirsk , Russia and
| | - Alya Venyaminova
- a Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences , Novosibirsk , Russia and
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21
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Guerra-Pérez N, Ramos E, García-Hernández M, Pinto C, Soto M, Martín ME, González VM. Molecular and Functional Characterization of ssDNA Aptamers that Specifically Bind Leishmania infantum PABP. PLoS One 2015; 10:e0140048. [PMID: 26457419 PMCID: PMC4601788 DOI: 10.1371/journal.pone.0140048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 09/21/2015] [Indexed: 02/05/2023] Open
Abstract
SUMMARY A poly (A)-binding protein from Leishmania infantum (LiPABP) has been recently cloned and characterized in our laboratory. Although this protein shows a very high homology with PABPs from other eukaryotic organisms including mammals and other parasites, exist divergences along the sequence that convert them in potential diagnostic markers and/or therapeutics targets. Aptamers are oligonucleotide ligands that are selected in vitro by their affinity and specificity for the target as a consequence of the particular tertiary structure that they are able to acquire depending on their sequence. Development of high-affinity molecules with the ability to recognize specifically Leishmania proteins is essential for the progress of this kind of study. RESULTS We have selected a ssDNA aptamer population against a recombinant 6xHIS-LiPABP protein (rLiPABP) that is able to recognize the target with a low Kd. Cloning, sequencing and in silico analysis of the aptamers obtained from the population yielded three aptamers (ApPABP#3, ApPABP#7 and ApPABP#11) that significantly bound to PABP with higher affinity than the naïve population. These aptamers were analyzed by ELONA and slot blot to establish affinity and specificity for rLiPABP. Results demonstrated that the three aptamers have high affinity and specificity for the target and that they are able to detect an endogenous LiPABP (eLiPABP) protein amount corresponding to 2500 L. infantum promastigotes in a significant manner. The functional analysis of the aptamers also revealed that ApPABP#11 disrupts the binding of both Myc-LiPABP and eLiPABP to poly (A) in vitro. On the other hand, these aptamers are able to bind and purify LiPABP from complex mixes. CONCLUSION Results presented here demonstrate that aptamers represent new reagents for characterization of LiPABP and that they can affect LiPABP activity. At this respect, the use of these aptamers as therapeutic tool affecting the physiological role of PABP has to be analyzed.
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Affiliation(s)
- Natalia Guerra-Pérez
- Laboratory of aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Edurne Ramos
- Laboratory of aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | | | - Celia Pinto
- Laboratory of aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Manuel Soto
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - M. Elena Martín
- Laboratory of aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Víctor M. González
- Laboratory of aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
- * E-mail:
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22
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Webster WAJ, McFadden GI. From the genome to the phenome: tools to understand the basic biology of Plasmodium falciparum. J Eukaryot Microbiol 2014; 61:655-71. [PMID: 25227912 DOI: 10.1111/jeu.12176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/01/2014] [Accepted: 09/02/2014] [Indexed: 11/30/2022]
Abstract
Malaria plagues one out of every 30 humans and contributes to almost a million deaths, and the problem could worsen. Our current therapeutic options are compromised by emerging resistance by the parasite to our front line drugs. It is thus imperative to better understand the basic biology of the parasite and develop novel drugs to stem this disease. The most facile approach to analyse a gene's function is to remove it from the genome or inhibit its activity. Although genetic manipulation of the human malaria parasite Plasmodium falciparum is a relatively standard procedure, there is no optimal method to perturb genes essential to the intraerythrocytic development cycle--the part of the life cycle that produces the clinical manifestation of malaria. This is a severe impediment to progress because the phenotype we wish to study is exactly the one that is so elusive. In the absence of any utilitarian way to conditionally delete essential genes, we are prevented from investigating the parasite's most vulnerable points. This review aims to focus on the development of tools identifying essential genes of P. falciparum and our ability to elicit phenotypic mutation.
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Affiliation(s)
- Wesley A J Webster
- Centre for Regional and Rural Futures, School of Life and Environmental Sciences, Deakin University, Burwood, 3125, Victoria, Australia; Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Melbourne, 3010, Victoria, Australia
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23
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Nucleic acid aptamers: research tools in disease diagnostics and therapeutics. BIOMED RESEARCH INTERNATIONAL 2014; 2014:540451. [PMID: 25050359 PMCID: PMC4090538 DOI: 10.1155/2014/540451] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/18/2014] [Indexed: 12/20/2022]
Abstract
Aptamers are short sequences of nucleic acid (DNA or RNA) or peptide molecules which adopt a conformation and bind cognate ligands with high affinity and specificity in a manner akin to antibody-antigen interactions. It has been globally acknowledged that aptamers promise a plethora of diagnostic and therapeutic applications. Although use of nucleic acid aptamers as targeted therapeutics or mediators of targeted drug delivery is a relatively new avenue of research, one aptamer-based drug “Macugen” is FDA approved and a series of aptamer-based drugs are in clinical pipelines. The present review discusses the aspects of design, unique properties, applications, and development of different aptamers to aid in cancer diagnosis, prevention, and/or treatment under defined conditions.
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24
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Liao Q, Shen J, Liu J, Sun X, Zhao G, Chang Y, Xu L, Li X, Zhao Y, Zheng H, Zhao Y, Wu Z. Genome-wide identification and functional annotation of Plasmodium falciparum long noncoding RNAs from RNA-seq data. Parasitol Res 2014; 113:1269-81. [PMID: 24522451 DOI: 10.1007/s00436-014-3765-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/10/2014] [Indexed: 11/25/2022]
Abstract
The life cycle of Plasmodium falciparum is very complex, with an erythrocytic stage that involves the invasion of red blood cells and the survival and growth of the parasite within the host. Over the past several decades, numbers of studies have shown that proteins exported by P. falciparum to the surface of infected red blood cells play a critical role in recognition and interaction with host receptors and are thus essential for the completion of the life cycle of P. falciparum. However, little is known about long noncoding RNAs (lncRNAs). In this study, we designed a computational pipeline to identify new lncRNAs of P. falciparum from published RNA-seq data and analyzed their sequences and expression features. As a result, 164 novel lncRNAs were found. The sequences and expression features of P. falciparum lncRNAs were similar to those of humans and mice: there was a lack of sequence conservation, low expression levels, and high expression coefficient of variance and co-expression with nearby coding sequences in the genome. Next, a coding/noncoding gene co-expression network for P. falciparum was constructed to further annotate the functions of novel and known lncRNAs. In total, the functions of 69 lncRNAs, including 44 novel lncRNAs, were annotated. The main functions of the lncRNAs included metabolic processes, biosynthetic processes, regulation of biological processes, establishment of localization, catabolic processes, cellular component organization, and interspecies interactions between organisms. Our results will provide clues to further the investigation of interactions between human hosts and parasites and the mechanisms of P. falciparum infection.
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Affiliation(s)
- Qi Liao
- Department of Preventive Medicine, School of Medicine, Ningbo University, Ningbo, People's Republic of China
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25
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Banerjee J, Nilsen-Hamilton M. Aptamers: multifunctional molecules for biomedical research. J Mol Med (Berl) 2013; 91:1333-42. [PMID: 24045702 DOI: 10.1007/s00109-013-1085-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 08/14/2013] [Accepted: 09/04/2013] [Indexed: 12/28/2022]
Abstract
Aptamers are single-stranded oligonucleotides that fold into well-defined three-dimensional shapes, allowing them to bind their targets with high affinity and specificity. They can be generated through an in vitro process called "Systemic Evolution of Ligands by Exponential Enrichment" and applied for specific detection, inhibition, and characterization of various targets like small organic and inorganic molecules, proteins, and whole cells. Aptamers have also been called chemical antibodies because of their synthetic origin and their similar modes of action to antibodies. They exhibit significant advantages over antibodies in terms of their small size, synthetic accessibility, and ability to be chemically modified and thus endowed with new properties. The first generation of aptamer drug "Macugen" was available for public use within 25 years of the discovery of aptamers. With others in the pipeline for clinical trials, this emerging field of medical biotechnology is raising significant interest. However, aptamers pose different problems for their development than for antibodies that need to be addressed to achieve practical applications. It is likely that current developments in aptamer engineering will be the basis for the evolution of improved future bioanalytical and biomedical applications. The present review discusses the development of aptamers for therapeutics, drug delivery, target validation and imaging, and reviews some of the challenges to fully realizing the promise of aptamers in biomedical applications.
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Affiliation(s)
- Jayeeta Banerjee
- Biology Department, Indian Institute of Science Education and Research (IISER), 900 NCL Innovation Park, Dr. Homi Bhabha Road, Pune, 411008, India,
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Germer K, Leonard M, Zhang X. RNA aptamers and their therapeutic and diagnostic applications. INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 4:27-40. [PMID: 23638319 PMCID: PMC3627066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/15/2013] [Indexed: 06/02/2023]
Abstract
RNA Aptamers refer to RNA oligonulceotides that are capable of binding to specific targets with high affinity and specificity. Through a process called Systematic Evolution of Ligands by EXponential enrichment (SELEX), a number of RNA aptamers have been identified against various targets including organic compounds, nucleotides, proteins and even whole cells and organisms. RNA aptamers have proven to be of high therapeutic and diagnostic value with recent FDA approval of the first aptamer drug and additional ones in the clinical pipelines. It has also been found to be a particularly useful tool for cell-type specific delivery of other RNA therapeutics like siRNA. All these establish RNA aptamers as one of the pivotal tools of the emerging RNA nanotechnology field in the fight against human diseases including cancer, viral infections and other diseases. This article summarizes the current advancement in the identification of RNA aptamers and also provides some examples of their therapeutic and diagnostic applications.
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Affiliation(s)
- Katherine Germer
- Department of Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine OH 45267
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Tonelli RR, Colli W, Alves MJM. Selection of binding targets in parasites using phage-display and aptamer libraries in vivo and in vitro. Front Immunol 2013; 3:419. [PMID: 23316203 PMCID: PMC3540409 DOI: 10.3389/fimmu.2012.00419] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 12/20/2012] [Indexed: 11/13/2022] Open
Abstract
Parasite infections are largely dependent on interactions between pathogen and different host cell populations to guarantee a successful infectious process. This is particularly true for obligatory intracellular parasites as Plasmodium, Toxoplasma, and Leishmania, to name a few. Adhesion to and entry into the cell are essential steps requiring specific parasite and host cell molecules. The large amount of possible involved molecules poses additional difficulties for their identification by the classical biochemical approaches. In this respect, the search for alternative techniques should be pursued. Among them two powerful methodologies can be employed, both relying upon the construction of highly diverse combinatorial libraries of peptides or oligonucleotides that randomly bind with high affinity to targets on the cell surface and are selectively displaced by putative ligands. These are, respectively, the peptide-based phage display and the oligonucleotide-based aptamer techniques. The phage display technique has been extensively employed for the identification of novel ligands in vitro and in vivo in different areas such as cancer, vaccine development, and epitope mapping. Particularly, phage display has been employed in the investigation of pathogen–host interactions. Although this methodology has been used for some parasites with encouraging results, in trypanosomatids its use is, as yet, scanty. RNA and DNA aptamers, developed by the SELEX process (Systematic Evolution of Ligands by Exponential Enrichment), were described over two decades ago and since then contributed to a large number of structured nucleic acids for diagnostic or therapeutic purposes or for the understanding of the cell biology. Similarly to the phage display technique scarce use of the SELEX process has been used in the probing of parasite–host interaction. In this review, an overall survey on the use of both phage display and aptamer technologies in different pathogenic organisms will be discussed. Using these techniques, recent results on the interaction of Trypanosoma cruzi with the host will be highlighted focusing on members of the 85 kDa protein family, a subset of the gp85/TS superfamily.
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Affiliation(s)
- R R Tonelli
- Departamento de Ciências Biológicas, Universidade Federal de São Paulo São Paulo, Brazil
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Identification of aptamers as specific binders and modulators of cell-surface receptor activity. Methods Mol Biol 2013; 986:17-39. [PMID: 23436403 DOI: 10.1007/978-1-62703-311-4_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In recent years, the SELEX (Systematic Evolution of Ligands by EXponential enrichment) technology has established itself as a powerful tool in basic research with promising applications in diagnostics and therapeutics. Oligonucleotides with high-affinities to their targets, denominated as aptamers, are obtained from partially random oligonucleotide pools by reiterative in vitro selection cycles and screening for binding activity. The original technique allowing the identification of aptamers binding to soluble targets, has recently been extended in order to produce aptamers binding to complex targets including receptors and ion channels embedded in the plasma membrane as well as whole cell surfaces or parasite organisms. In addition to discussing the most recent developments with focus on possible diagnostic and therapeutic application, we provide a simple protocol which has been successfully used to select for RNA aptamers as allosteric modulators of nicotinic receptor activity.
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29
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Kim JY, Kim HH, Shin HL, Sohn Y, Kim H, Lee SW, Lee WJ, Lee HW. Genetic variation of aldolase from Korean isolates of Plasmodium vivax and its usefulness in serodiagnosis. Malar J 2012; 11:159. [PMID: 22569198 PMCID: PMC3413559 DOI: 10.1186/1475-2875-11-159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 05/08/2012] [Indexed: 11/17/2022] Open
Abstract
Background The malaria aldolase is widely used as rapid diagnostic test (RDT), but the efficacy in aspect of its serological effectiveness in diagnosis is not known. The genetic variation of Korean isolates was analysed and recombinant aldolase was evaluated as a serological antigen in Plasmodium vivax malaria. Methods Genomic DNA was purified and the aldolase gene of P. vivax from 25 patients’ blood samples was amplified. The samples came from 5 epidemic areas; Bucheon-si, Gimpo-si, Paju-si of Gyeonggido, Gangwha-gun of Incheon metropolitan city, and Cheorwon of Gangwon-do, South Korea. The antigenicity of the recombinant aldolase was tested by western blot and enzyme-linked immunosorbent assay (ELISA). Results Sequence analysis of 25 Korean isolates of P. vivax showed that the open reading frame (ORF) of 1,110 nucleotides encoded a deduced protein of 369 amino acids (aa). This ORF showed 100% homology with the P. vivax Sal I strain (XM_00165894) and P. vivax WDK strain (AF247063), 87.4% homology with Plasmodium falciparum (AF179421), 90.6% homology with Plasmodium chabaudi (AF247060), 89.5% homology with Plasmodium vinckei (AF247061), and 96.7% homology with Plasmodium knowlesi. A single nucleotide polymorphism (SNP) at nucleotide 180 (G to A, n = 5) was also observed in the isolates. The expressed recombinant protein had a molecular weight of approximately 31 kDa (monomeric form) and 62 kDa (dimeric form) as analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Among 109 P. vivax patients, 32 (29.4%) had positive in an enzyme-linked absorbance assay (ELISA). This result showed significant correlation between ELISA and an indirect fluorescent antibody test (IFAT) (P < 0.0001). Conclusions The aldolase gene from Korean isolates of P. vivax showed one SNP at nucleotide position 180; this SNP mutant was discovered in only the western part of Han River, and included the regions of Ganghwa, Gimpo, and Bucheon. Based on the results, the relationship between antibody production against aldolase and the pattern of disease onset should be more investigated before using aldolase for serodiagnosis.
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Affiliation(s)
- Jung-Yeon Kim
- Division of Malaria and Parasitic Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongwon-gun 363-951, Republic of Korea
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Gay F, Zougbédé S, N’Dilimabaka N, Rebollo A, Mazier D, Moreno A. Cerebral malaria: What is known and what is on research. Rev Neurol (Paris) 2012; 168:239-56. [DOI: 10.1016/j.neurol.2012.01.582] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 01/27/2012] [Indexed: 01/21/2023]
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31
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Göringer HU. Parasite-specific aptamers as biosynthetic reagents and potential pharmaceuticals. Trends Parasitol 2012; 28:106-13. [PMID: 22300805 DOI: 10.1016/j.pt.2011.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 12/28/2011] [Accepted: 12/29/2011] [Indexed: 10/14/2022]
Abstract
Aptamers are short, synthetic nucleic acid molecules. They are generated by a Darwinian-type in vitro evolution method known as 'systematic evolution of ligands by exponential enrichment' (SELEX). SELEX represents an experimental platform to identify rare ligands with predetermined functionality from combinatorial nucleic acid libraries. Since its discovery about 20 years ago the method has been instrumental in identifying a large number of aptamers that recognize targets of very different chemistry and molecular complexity. Although aptamers have been converted into sophisticated biomolecular tools for a diverse set of technologies, only a limited number of aptamers have been selected as binding reagents for parasites or parasite-derived molecules. Here the published examples of aptamers that target Leishmania-, Trypanosoma- and Plasmodia-specific molecules are reviewed.
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Affiliation(s)
- H Ulrich Göringer
- Genetics, Darmstadt University of Technology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
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Davydova A, Vorobjeva M, Venyaminova A. Escort aptamers: new tools for the targeted delivery of therapeutics into cells. Acta Naturae 2011; 3:12-29. [PMID: 22649701 PMCID: PMC3347615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Escort aptamers are DNA or RNA sequences with high affinity to certain cell-surface proteins, which can be used for targeted delivery of various agents into cells of a definite type. The peculiarities of the selection of escort aptamers are discussed in this review. The methods used in selection of escort aptamers via the SELEX technique are considered, including selection against isolated cell-surface proteins, cell fragments, living eukaryotic cells, and bacteria. Particular attention is given to the design and chemical modification of escort aptamers. The different fields of application of escort aptamers are described, including the targeted delivery of siRNAs, nanoparticles, toxins, and photoagents, as well as the identification of specific cell markers and the detection or isolation of cells of a definite type. The potential for the application of escort aptamers in the development of new therapeutic agents and diagnostic systems is also discussed.
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Affiliation(s)
- A.S. Davydova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch,
Russian Academy of Sciences
| | - M.A. Vorobjeva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch,
Russian Academy of Sciences
| | - A.G. Venyaminova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch,
Russian Academy of Sciences
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Cibiel A, Dupont DM, Ducongé F. Methods To Identify Aptamers against Cell Surface Biomarkers. Pharmaceuticals (Basel) 2011. [PMCID: PMC4058655 DOI: 10.3390/ph4091216] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Aptamers are nucleic acid-based ligands identified through a process of molecular evolution named SELEX (Systematic Evolution of Ligands by Exponential enrichment). During the last 10-15 years, numerous aptamers have been developed specifically against targets present on or associated with the surface of human cells or infectious pathogens such as viruses, bacteria, fungi or parasites. Several of the aptamers have been described as potent probes, rivalling antibodies, for use in flow cytometry or microscopy. Some have also been used as drugs by inhibiting or activating functions of their targets in a manner similar to neutralizing or agonistic antibodies. Additionally, it is straightforward to conjugate aptamers to other agents without losing their affinity and they have successfully been used in vitro and in vivo to deliver drugs, siRNA, nanoparticles or contrast agents to target cells. Hence, aptamers identified against cell surface biomarkers represent a promising class of ligands. This review presents the different strategies of SELEX that have been developed to identify aptamers for cell surface-associated proteins as well as some of the methods that are used to study their binding on living cells.
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Affiliation(s)
- Agnes Cibiel
- CEA, DSV, IBM, Service Hospitalier Frédéric Joliot (SHFJ), 4 place du général Leclerc, 91401 Orsay, France; E-Mail: (A.C.)
- INSERM U1023, 4 place du général Leclerc, 91401 Orsay, France
- Université Paris Sud, 4 place du général Leclerc, 91401 Orsay, France
| | - Daniel Miotto Dupont
- Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C, Denmark; E-Mail: (D.M.D.)
| | - Frédéric Ducongé
- CEA, DSV, IBM, Service Hospitalier Frédéric Joliot (SHFJ), 4 place du général Leclerc, 91401 Orsay, France; E-Mail: (A.C.)
- INSERM U1023, 4 place du général Leclerc, 91401 Orsay, France
- Université Paris Sud, 4 place du général Leclerc, 91401 Orsay, France
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-169-867-766; Fax: +33-169-867-786
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Lee C, Chung KW, Kim TS, Choi KM, Choi YK, Chung NJ, Rhie HG, Lee HS, Lee SJ, Lee HW. Trials for the co-expression of the merozoite surface protein-1 and circumsporozoite protein genes of Plasmodium vivax. Exp Parasitol 2011; 129:227-33. [PMID: 21907198 DOI: 10.1016/j.exppara.2011.08.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 08/16/2011] [Accepted: 08/17/2011] [Indexed: 12/31/2022]
Abstract
Merozoite surface protein-1 (MSP-1), a major asexual blood stage antigen, and circumsporozoite protein (CSP), a component of sporozoites that includes a Plasmodium vivax B-cell epitope, are strong candidates for use in a malaria vaccine. A chimeric recombinant gene containing portions of both msp-1 and csp from P. vivax separated by Pro-Gly linker motif was generated. The construct gene was named mlc (msp-1, linker, and csp). The MLC chimeric recombinant protein had a molecular weight of approximately 25 kDa when expressed in Escherichia coli, as determined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The purified chimeric protein reacted with the sera of patients infected with P. vivax but not with the sera of uninfected patients according to western blot analysis. The chimeric protein reacted well with sera of malaria patients (109/115, 94.78%) as assessed with enzyme-linked immunosorbent assay (ELISA). BALB/c mice that were orally immunized with the MLC chimeric recombinant protein successfully produced antigen-specific antibodies. Additionally, levels of the Th1-associated cytokines IL-12(p40), TNF-α, and IFN-γ were significantly increased in the spleens of the BALB/c mice. Therefore, the E. coli-expressed MLC chimeric recombinant protein might be used as a valuable vaccine candidate for oral immunization against vivax malaria.
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Affiliation(s)
- Choonghee Lee
- Institute of Global Environment and Department of Biology, Kyung Hee University, Seoul 130-701, Republic of Korea
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Li H, Ding X, Peng Z, Deng L, Wang D, Chen H, He Q. Aptamer selection for the detection of Escherichia coli K88. Can J Microbiol 2011; 57:453-9. [PMID: 21627466 DOI: 10.1139/w11-030] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this study, the first group of single-stranded DNA aptamers that are highly specific to enterotoxigenic Escherichia coli (ETEC) K88 was obtained from an enriched oligonucleotide pool by the SELEX (Systematic Evolution of Ligands by Exponential Enrichment) procedure, during which the K88 fimbriae protein was used as the target and bovine serum albumin as counter targets. These aptamers were applied successfully in the detection of ETEC K88. They were then grouped under different families based on the similarity of their secondary structure and the homology of their primary sequence. Four sequences from different families were deliberately chosen for further characterization by fluorescence analysis. Having the advantage of high sensitivity, fluorescence photometry was selected as single-stranded DNA quantification method during the SELEX process. Aptamers with the highest specificity and affinity were analyzed to evaluate binding ability with E. coli. Since ETEC K88 is the only type of bacterium that expressed abundant K88 fimbriae, the selected aptamers against the K88 fimbriae protein were able to specifically identify ETEC K88 among other bacteria. This method of detecting ETEC K88 by aptamers can also be applied to bacteria other than ETEC K88.
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Affiliation(s)
- Hua Li
- The Co-construction Laboratory of Microbial Molecular Biology of Province Department and Ministry of Science and Technology, College of Life Sciences, Hunan Normal University, Changsha, People's Republic of China
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John CC, Kutamba E, Mugarura K, Opoka RO. Adjunctive therapy for cerebral malaria and other severe forms of Plasmodium falciparum malaria. Expert Rev Anti Infect Ther 2011; 8:997-1008. [PMID: 20818944 DOI: 10.1586/eri.10.90] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Severe malaria due to Plasmodium falciparum causes more than 800,000 deaths every year. Primary therapy with quinine or artesunate is generally effective in controlling P. falciparum parasitemia, but mortality from cerebral malaria and other forms of severe malaria remains unacceptably high. Long-term cognitive impairment is also common in children with cerebral malaria. Of the numerous adjunctive therapies for cerebral malaria and severe malaria studied over the past five decades, only one (albumin) was associated with a reduction in mortality. In this article, we review past and ongoing studies of adjunctive therapy, and examine the evidence of efficacy for newer therapies, including inhibitors of cytoadherence (e.g., levamisole), immune modulators (e.g., rosiglitazone), agents that increase nitric oxide levels (e.g., arginine) and neuroprotective agents (e.g., erythropoietin).
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Affiliation(s)
- Chandy C John
- Center for Global Pediatrics, 717 Delaware Street SE, Room 363, Minneapolis, MN 55455, USA.
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Molecular cloning and expression of the VK247 circumsporozoite protein for serodiagnosis of variant form Plasmodium vivax. Parasitol Res 2011; 108:1275-82. [PMID: 21318386 DOI: 10.1007/s00436-010-2177-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Accepted: 11/17/2010] [Indexed: 10/18/2022]
Abstract
Plasmodium vivax is classified into two serotypes, VK210 [the dominant form-GDRA(D/A)GQPA repeats] and VK247 [the variant form-ANGA(G/D)(N/D)QPG repeats], based on sequence variation of the repeat region of the circumsporozoite (CS) protein gene. Genomic DNA for the variant CS protein gene was obtained from field isolate strains in Myanmar. The repetitive region has highly 19 immunogenic repeats flanked by non-repeat stretches of amino acids. The sequence including this region (717 bp) was subcloned into the expression vector pQE30 and expressed in Escherichia coli. The expressed recombinant protein has a molecular weight of about 50 kDa as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Anti-VK247 antibodies were found in malaria patients who have been exposed to variant form of P. vivax in western blot analysis. Therefore, this recombinant protein might be a useful tool in serodiagnosis of malaria patients who have been infected with variant form of P. vivax.
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Nucleic acid aptamers targeting cell-surface proteins. Methods 2011; 54:215-25. [PMID: 21300154 DOI: 10.1016/j.ymeth.2011.02.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 01/21/2011] [Accepted: 02/01/2011] [Indexed: 12/21/2022] Open
Abstract
Aptamers are chemical antibodies that bind to their targets with high affinity and specificity. These short stretches of nucleic acids are identified using a repetitive in vitro selection and partitioning technology called SELEX (Systematic Evolution of Ligands by EXponential enrichment). Since the emergence of this technology, many modifications and variations have been introduced to enable the selection of specific ligands, even for implausible targets. For membrane protein, the selection scheme can be chosen depending upon the availability of the system, the protein characteristics and the application required. Aptamers have been generated for a significant number of disease-associated membrane proteins and have been shown to have considerable diagnostic and therapeutic importance. In this article, we review the SELEX process used for identification of aptamers that target cell-surface proteins and recapitulate their use as therapeutic and diagnostic reagents.
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Tang J, Guo L, Shen R, Yu T, Xu H, Liu H, Ma X, Xie J. Quantification of rHuEPO-α by magnetic beads-based aptameric real-time PCR assay. Analyst 2010; 135:2924-9. [PMID: 20877820 DOI: 10.1039/c0an00423e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recombinant human erythropoietin (rHuEPO) is one kind of important hematopoietic growth factor, which is widely used in anaemia treatment as well as sometimes abused by endurance athletes. Based on a set of anti-rHuEPO-α aptamers successfully in vitro isolated in our laboratory, we herein describe a novel magnetic beads-based aptameric real-time PCR assay for the accurate quantification of rHuEPO-α, which combined the specific recognition with amplification capability of aptamers. Two detection strategies, termed 'recognition-after-hybridization' and 'recognition-before-hybridization' respectively, were constructed and compared. Strategy B, i.e.'recognition-before-hybridization', was finally adopted as the preferred one to measure rHuEPO-α. A limit of detection (LOD) of 1 pmol/L rHuEPO-α and a wide dynamic range from 6 pmol/L to 100 nmol/L were obtained for physiological buffer. Furthermore, a LOD of 6 pmol/L was achieved for more complicated matrix-half diluted artificial urine. These results indicate that the anti-rHuEPO-α aptamer fits the high sensitive detection of rHuEPO-α very well. The use of the aptamer with magnetic beads-based real-time PCR allows a direct and novel assay for rHuEPO-α.
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Affiliation(s)
- Jijun Tang
- Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
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Marton S, Reyes-Darias JA, Sánchez-Luque FJ, Romero-López C, Berzal-Herranz A. In vitro and ex vivo selection procedures for identifying potentially therapeutic DNA and RNA molecules. Molecules 2010; 15:4610-38. [PMID: 20657381 PMCID: PMC6257598 DOI: 10.3390/molecules15074610] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 06/17/2010] [Accepted: 06/24/2010] [Indexed: 02/05/2023] Open
Abstract
It was only relatively recently discovered that nucleic acids participate in a variety of biological functions, besides the storage and transmission of genetic information. Quite apart from the nucleotide sequence, it is now clear that the structure of a nucleic acid plays an essential role in its functionality, enabling catalysis and specific binding reactions. In vitro selection and evolution strategies have been extremely useful in the analysis of functional RNA and DNA molecules, helping to expand our knowledge of their functional repertoire and to identify and optimize DNA and RNA molecules with potential therapeutic and diagnostic applications. The great progress made in this field has prompted the development of ex vivo methods for selecting functional nucleic acids in the cellular environment. This review summarizes the most important and most recent applications of in vitro and ex vivo selection strategies aimed at exploring the therapeutic potential of nucleic acids.
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Affiliation(s)
- Soledad Marton
- Instituto de Parasitología y Biomedicina López-Neyra, CSIC, P.T. Ciencias de la Salud, Av. del Conocimiento s/n, Armilla, 18100 Granada, Spain.
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