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Celis-Giraldo C, Ordoñez D, Díaz-Arévalo D, Bohórquez MD, Ibarrola N, Suárez CF, Rodríguez K, Yepes Y, Rodríguez A, Avendaño C, López-Abán J, Manzano-Román R, Patarroyo MA. Identifying major histocompatibility complex class II-DR molecules in bovine and swine peripheral blood monocyte-derived macrophages using mAb-L243. Vaccine 2024; 42:3445-3454. [PMID: 38631956 DOI: 10.1016/j.vaccine.2024.04.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/04/2024] [Accepted: 04/13/2024] [Indexed: 04/19/2024]
Abstract
Major histocompatibility complex class II (MHC-II) molecules are involved in immune responses against pathogens and vaccine candidates' immunogenicity. Immunopeptidomics for identifying cancer and infection-related antigens and epitopes have benefited from advances in immunopurification methods and mass spectrometry analysis. The mouse anti-MHC-II-DR monoclonal antibody L243 (mAb-L243) has been effective in recognising MHC-II-DR in both human and non-human primates. It has also been shown to cross-react with other animal species, although it has not been tested in livestock. This study used mAb-L243 to identify Staphylococcus aureus and Salmonella enterica serovar Typhimurium peptides binding to cattle and swine macrophage MHC-II-DR molecules using flow cytometry, mass spectrometry and two immunopurification techniques. Antibody cross-reactivity led to identifying expressed MHC-II-DR molecules, together with 10 Staphylococcus aureus peptides in cattle and 13 S. enterica serovar Typhimurium peptides in swine. Such data demonstrates that MHC-II-DR expression and immunocapture approaches using L243 mAb represents a viable strategy for flow cytometry and immunopeptidomics analysis of bovine and swine antigen-presenting cells.
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Affiliation(s)
- Carmen Celis-Giraldo
- Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Bogotá, Colombia; PhD Programme in Tropical Health and Development, Doctoral School "Studii Salamantini", Universidad de Salamanca, Salamanca, Spain
| | - Diego Ordoñez
- Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Bogotá, Colombia; PhD Programme in Tropical Health and Development, Doctoral School "Studii Salamantini", Universidad de Salamanca, Salamanca, Spain
| | - Diana Díaz-Arévalo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Michel D Bohórquez
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia; MSc Programme in Microbiology, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Nieves Ibarrola
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (IBMCC), CSIC-University of Salamanca, Salamanca, Spain
| | - Carlos F Suárez
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Kewin Rodríguez
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Yoelis Yepes
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Alexander Rodríguez
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Catalina Avendaño
- Department of Immunology and Theranostics, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, National Medical Center, Duarte, CA, United States
| | - Julio López-Abán
- Infectious and Tropical Diseases Group (e-INTRO), IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca - Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Pharmacy Faculty, Universidad de Salamanca, C/ L. Méndez Nieto s/n, 37007 Salamanca, Spain
| | - Raúl Manzano-Román
- Infectious and Tropical Diseases Group (e-INTRO), IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca - Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Pharmacy Faculty, Universidad de Salamanca, C/ L. Méndez Nieto s/n, 37007 Salamanca, Spain
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia; Microbiology Department, Faculty of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia.
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Valiant WG, Cai K, Vallone PM. A history of adventitious agent contamination and the current methods to detect and remove them from pharmaceutical products. Biologicals 2022; 80:6-17. [DOI: 10.1016/j.biologicals.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/26/2022] [Accepted: 10/25/2022] [Indexed: 11/08/2022] Open
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A practical approach for gmp-compliant validation of real-time PCR method for mycoplasma detection in human mesenchymal stromal cells as advanced therapy medicinal product. Biologicals 2021; 73:31-40. [PMID: 34362616 DOI: 10.1016/j.biologicals.2021.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Manufacturing of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP) for clinical use involves an ex vivo expansion, which leads to a risk of contamination by microbiological agents. Even if manufacturing under Good Manufacturing Practice (GMP) license minimizes this risk, contamination of cell cultures by mycoplasmas still represents a widespread problem. Furthermore, the absence of mycoplasma contamination represents one of ATMPs release criteria. Since July 2007, European Pharmacopoeia (EuPh) offers the possibility to replace official mycoplasma detection methods with Nucleic Acid Amplification techniques, after suitable validation. As an Italian authorized Cell Factory, we developed an in-house GMP-compliant validation of real-time PCR method for mycoplasma detection in human Mesenchymal Stromal Cells, according to EuPh sec. 2.6.7 and International Conference on Harmonization Q2. MATERIALS AND METHODS The study was performed in compliance with GMP international requirements with MycoSEQ™ Mycoplasma Detection Assay (Thermofisher) on QuantStudio5 real-Time PCR (Applied Biosystems). Assay validation was developed to evaluate sensitivity, interferences matrix-related, specificity and robustness. RESULTS MycoSEQ™ Mycoplasma Detection Assay has been successfully validated on human Mesenchymal Stromal Cells as results comply with validation protocol acceptance criteria. CONCLUSIONS MycoSEQ™ Mycoplasma Detection Assay is a fast, sensitive and specific PCR-based Nucleic Acid Test assay that can be used as an alternative to official mycoplasma test methods for lot release of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP). Moreover, our study underlines the presence of interference on real-time PCR reaction due to matrix composition, pointing out a practical approach for method validation (i.e interference removal).
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Knoblach B, Ishida R, Hobman TC, Rachubinski RA. Peroxisomes exhibit compromised structure and matrix protein content in SARS-CoV-2-infected cells. Mol Biol Cell 2021; 32:1273-1282. [PMID: 34010015 PMCID: PMC8351553 DOI: 10.1091/mbc.e21-02-0074] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that has triggered global health and economic crises. Here we report the effects of SARS-CoV-2 infection on peroxisomes of human cell lines Huh-7 and SK-N-SH. Peroxisomes undergo dramatic changes in morphology in SARS-CoV-2-infected cells. Rearrangement of peroxisomal membranes is followed by redistribution of peroxisomal matrix proteins to the cytosol, resulting in a dramatic decrease in the number of mature peroxisomes. The SARS-CoV-2 ORF14 protein was shown to interact physically with human PEX14, a peroxisomal membrane protein required for matrix protein import and peroxisome biogenesis. Given the important roles of peroxisomes in innate immunity, SARS-CoV-2 may directly target peroxisomes, resulting in loss of peroxisome structural integrity, matrix protein content and ability to function in antiviral signaling.
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Affiliation(s)
- Barbara Knoblach
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Ray Ishida
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Tom C Hobman
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.,Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Richard A Rachubinski
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Dreolini L, Cullen M, Yung E, Laird L, Webb JR, Nelson BH, Hay KA, Balasundaram M, Kekre N, Holt RA. A Rapid and Sensitive Nucleic Acid Amplification Technique for Mycoplasma Screening of Cell Therapy Products. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:393-399. [PMID: 32128343 PMCID: PMC7044503 DOI: 10.1016/j.omtm.2020.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/17/2020] [Indexed: 10/29/2022]
Abstract
Mycoplasma species (spp.) bacteria can infect cell cultures, posing a potential threat to recipients of cell therapy products. Conventional Mycoplasma testing methods are highly sensitive but typically require a minimum of 28 days to produce results. This delay is problematic if rapid results are needed to inform treatment decisions. Nucleic acid amplification technique (NAT) methods have been gaining favor for Mycoplasma testing due to their speed and specificity; however, they must first be qualified as meeting or exceeding the sensitivity of the compendial method. We present herein a NAT method for the detection of Mycoplasma that circumvents the need for live Mycoplasma spp. in the test procedure by instead being qualified using Mycoplasma spp. genomic DNA. We have demonstrated a lower limit of detection that exceeds the regulatory requirements set by Health Canada. This assay is now being used to screen clinical cell therapy products manufactured at our center.
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Affiliation(s)
- Lisa Dreolini
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada
| | - Mark Cullen
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada
| | - Eric Yung
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada
| | - Lawrence Laird
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada
| | - John R Webb
- Trev and Joyce Deeley Research Centre, BC Cancer, Victoria, BC V8R 6V5, Canada.,Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Brad H Nelson
- Trev and Joyce Deeley Research Centre, BC Cancer, Victoria, BC V8R 6V5, Canada.,Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Kevin A Hay
- Terry Fox Laboratory, BC Cancer, Vancouver, BC V5Z 1L3, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Miruna Balasundaram
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada
| | - Natasha Kekre
- Blood and Marrow Transplant Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Robert A Holt
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.,Molecular Biology & Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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Mycoplasma infection of cultured cells induces oxidative stress and attenuates cellular base excision repair activity. Mutat Res 2019; 845:403054. [PMID: 31561888 DOI: 10.1016/j.mrgentox.2019.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 04/11/2019] [Accepted: 05/19/2019] [Indexed: 11/23/2022]
Abstract
Mycoplasma contamination is a major concern for in vitro cell culture models as its resistance to most antibiotics, which makes the prevention and treatment of infection challenging. Furthermore, numerous studies show that Mycoplasma infection alters a variety of cellular processes, in a wide range of cell lines. However, there is a lack of information pertaining to the effects of Mycoplasma infection on genomic stability. In this study, a dopaminergic neuronal cell line (BE-M17), a popular in vitro model for Parkinson's disease, was used to evaluate the effect of Mycoplasma infection on genomic instability, and base excision repair (BER) activity, using single cell gel electrophoresis (the comet assay). The results showed that Mycoplasma infection induced oxidative stress in the absence of an inflammatory response, with markedly increased levels of DNA damage [strand breaks/alkali-labile sites (SB/ALS), and oxidised purines], compared to uninfected cells. The source of the oxidative stress may have been increased ROS generation, or attenuation of cellular antioxidant capacity (or a combination of both). Uninfected cells initially repaired SB/ALS more rapidly than infected cells, although SB/ALS were fully repaired in both uninfected and infected cells 2 h after H2O2 challenge. However, while uninfected cells showed complete repair of oxidised purines within 24 h, for the infected cells, these were not fully repaired even after 30 h. In conclusion, this study showed that not only does Mycoplasma infection induce oxidative stress and DNA damage, but it also decreases the efficiency of the main pathway responsible for the repair of oxidatively damaged DNA i.e. BER. In this in vitro model, there is no mechanism for infection-induced inflammation, which could be a source of increased ROS production. Therefore, further studies are needed to evaluate how Mycoplasma infection causes oxidatively damaged DNA, and how it modulates cellular DNA repair.
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Fisher AC, Kamga MH, Agarabi C, Brorson K, Lee SL, Yoon S. The Current Scientific and Regulatory Landscape in Advancing Integrated Continuous Biopharmaceutical Manufacturing. Trends Biotechnol 2019; 37:253-267. [DOI: 10.1016/j.tibtech.2018.08.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/20/2018] [Accepted: 08/29/2018] [Indexed: 01/19/2023]
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8
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Mbelo S, Gay V, Blanchard S, Abachin E, Falque S, Lechenet J, Poulet H, de Saint-Vis B. Development of a highly sensitive PCR/DNA chip method to detect mycoplasmas in a veterinary modified live vaccine. Biologicals 2018; 54:22-27. [PMID: 29753589 DOI: 10.1016/j.biologicals.2018.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 03/21/2018] [Accepted: 05/01/2018] [Indexed: 10/16/2022] Open
Abstract
Mycoplasmas are potential contaminants that introduce undesirable changes in mammalian cell cultures. They frequently contaminate cell substrates and other starting materials used for manufacturing cell-derived biologics, such as vaccines and pharmaceutical products. Mycoplasma purity testing of live vaccines, active ingredients, raw material, and seed lots is required during vaccine production. Previously, testing using a time-consuming, costly 28-day culture assay, which lacks sensitivity for species that do not grow in culture, was required in the European Pharmacopoeia (Ph. Eur). But now nucleic acid amplification techniques (NATs) can be used. NATs provide rapid results and are sensitive. We evaluated the sensitivity and specificity of a commercially-available NAT to detect individual mycoplasma DNA in a veterinary modified live vaccine using five reference strains recommended by the Ph. Eur. Our results showed that this NAT-based method can be used to detect mycoplasma in spiked live vaccine, without interference from the vaccine components, with a limit of detection of 10 CFU/mL, as required by the Ph. Eur. Its specificity was demonstrated since no mycoplasmas were detected in non-spiked vaccine. This method is undergoing validation as a replacement for the conventional culture method in the production of veterinary live vaccines.
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Affiliation(s)
- Sylvie Mbelo
- Merial, Lyon Gerland 254 rue Marcel Mérieux, 69007 Lyon, France(1).
| | - Virginie Gay
- Merial, Lyon Gerland 254 rue Marcel Mérieux, 69007 Lyon, France(1)
| | | | - Eric Abachin
- Sanofi Pasteur, ARD IMMIC, 1541 avenue Marcel Mérieux, 69280 Marcy l'Etoile, France
| | - Stephanie Falque
- Sanofi Pasteur, ARD IMMIC, 1541 avenue Marcel Mérieux, 69280 Marcy l'Etoile, France
| | - Jacques Lechenet
- Merial, Lyon Gerland 254 rue Marcel Mérieux, 69007 Lyon, France(1)
| | - Hervé Poulet
- Merial, Lyon Gerland 254 rue Marcel Mérieux, 69007 Lyon, France(1)
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Vega-Orellana O, Poveda JB, Rosales RS, Bradbury JM, Poveda CG, Mederos-Iriarte LE, Tavío MM, Ramírez AS. Comparison of different NAT assays for the detection of microorganisms belonging to the class Mollicutes. BMC Vet Res 2017; 13:195. [PMID: 28646859 PMCID: PMC5483278 DOI: 10.1186/s12917-017-1116-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 06/16/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mollicutes detection can be cumbersome due to their slow growth in vitro. For this reason, the use of DNA based on generic molecular tests represents an alternative for rapid, sensitive and specific detection of these microorganism. For this reason, six previously described nucleic acid testing assays were compared to evaluate their ability to detect microorganisms belonging to the class Mollicutes. METHODS A panel of 61 mollicutes, including representatives from the Mycoplasma, Acholeplasma, Mesoplasma, Spiroplasma and Ureaplasma genus, were selected to evaluate the sensitivity and specificity of these assays. A total of 21 non-mollicutes, including closely related non-mollicutes species, were used to evaluate specificity. Limits of detection were calculated to determine the analytical sensitivity of the assays. The two best performing assays were subsequently adapted into real-time PCR format, followed by melting curve analysis. RESULTS Both assays performed satisfactorily, with a 100% specificity described for both assays. The detection limits were found to be between 10-4 and 10-5 dilutions, equivalent to 15 to 150 genome copies approximately. Based on our work, both van Kuppeveld and Botes real-time PCR assays were found to be the best performing tests in terms of sensitivity and specificity. Furthermore, Botes real-time PCR assay could detect phytoplasmas as well. CONCLUSIONS These assays can be very useful for the rapid, specific and sensitive screening cell line contaminants, clinical samples as well as detecting non-culturable, unknown species of mollicutes or mollicutes whose growth is slow or difficult.
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Affiliation(s)
- O. Vega-Orellana
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
| | - J. B. Poveda
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
| | - R. S. Rosales
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
| | - J. M. Bradbury
- University of Liverpool, School of Veterinary Science, Leahurst Campus, Neston, CH64 7TE UK
| | - C. G. Poveda
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
| | - L. E. Mederos-Iriarte
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
| | - M. M. Tavío
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
- Microbiología, Departamento de Ciencias Clínicas, Facultad de Ciencias de la Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - A. S. Ramírez
- Unidad de Epidemiología y Medicina Preventiva, Facultad de Veterinaria, Universidad de Las Palmas de Gran Canaria, C/Trasmontaña s/n, 35413 Arucas, Gran Canaria Spain
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Synergistic effects of deleting multiple nonessential elements in nonreplicative HSV-1 BAC genomic vectors play a critical role in their viability. Gene Ther 2017; 24:433-440. [PMID: 28553928 DOI: 10.1038/gt.2017.43] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 04/15/2017] [Accepted: 05/19/2017] [Indexed: 11/09/2022]
Abstract
Nonreplicative Herpes simplex virus type-1 (HSV-1) genomic vectors have already entered into clinical trials for neurological gene therapy thanks to their scalable growth in permissive cells. However, the small transgene capacity of this type of HSV-1 vectors currently used in the clinic represents an important limiting factor as a gene delivery system. To develop high-capacity nonreplicative genomic HSV-1 vectors, in this study we have characterized a series of multiply deleted mutants which we have constructed in bacterial artificial chromosomes (BACs), removing up to 24 kb of unstable or dispensable genomic sequences to allow insertion of transgenes up to this size. We show that synergistic effects of deletions of: the HSV-1 replication origins oriS and oriL, the HSV-1 internal repeat region, the remaining ICP4 gene copy and the genes encoding for ICP27, UL56, UL55, can severely reduce the growth of these HSV-1 vectors. Given that several of these elements have been characterized as 'non-essential' for viral growth in cell culture by single-deletion experiments of wild-type HSV-1, our study highlights the need to re-evaluate their functional contribution in the context of multiply deleted nonreplicative HSV-1 genomic vectors. Our BAC mutants described here can serve as useful starting platforms to accelerate HSV-1 vector development.
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Kawamata H, Peixoto P, Konrad C, Palomo G, Bredvik K, Gerges M, Valsecchi F, Petrucelli L, Ravits JM, Starkov A, Manfredi G. Mutant TDP-43 does not impair mitochondrial bioenergetics in vitro and in vivo. Mol Neurodegener 2017; 12:37. [PMID: 28482850 PMCID: PMC5422931 DOI: 10.1186/s13024-017-0180-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/29/2017] [Indexed: 12/13/2022] Open
Abstract
Background Mitochondrial dysfunction has been linked to the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Functional studies of mitochondrial bioenergetics have focused mostly on superoxide dismutase 1 (SOD1) mutants, and showed that mutant human SOD1 impairs mitochondrial oxidative phosphorylation, calcium homeostasis, and dynamics. However, recent reports have indicated that alterations in transactivation response element DNA-binding protein 43 (TDP-43) can also lead to defects of mitochondrial morphology and dynamics. Furthermore, it was proposed that TDP-43 mutations cause oxidative phosphorylation impairment associated with respiratory chain defects and that these effects were caused by mitochondrial localization of the mutant protein. Here, we investigated the presence of bioenergetic defects in the brain of transgenic mice expressing human mutant TDP-43 (TDP-43A315T mice), patient derived fibroblasts, and human cells expressing mutant forms of TDP-43. Methods In the brain of TDP-43A315T mice, TDP-43 mutant fibroblasts, and cells expressing mutant TDP-43, we tested several bioenergetics parameters, including mitochondrial respiration, ATP synthesis, and calcium handling. Differences between mutant and control samples were evaluated by student t-test or by ANOVA, followed by Bonferroni correction, when more than two groups were compared. Mitochondrial localization of TDP-43 was investigated by immunocytochemistry in fibroblasts and by subcellular fractionation and western blot of mitochondrial fractions in mouse brain. Results We did not observe defects in any of the mitochondrial bioenergetic functions that were tested in TDP-43 mutants. We detected a small amount of TDP-43A315T peripherally associated with brain mitochondria. However, there was no correlation between TDP-43 associated with mitochondria and respiratory chain dysfunction. In addition, we observed increased calcium uptake in mitochondria from TDP-43A315T mouse brain and cells expressing A315T mutant TDP-43. Conclusions While alterations of mitochondrial morphology and dynamics in TDP-43 mutant neurons are well established, the present study did not demonstrate oxidative phosphorylation defects in TDP-43 mutants, in vitro and in vivo. On the other hand, the increase in mitochondrial calcium uptake in A315T TDP-43 mutants was an intriguing finding, which needs to be investigated further to understand its mechanisms and potential pathogenic implications.
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Affiliation(s)
- Hibiki Kawamata
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Pablo Peixoto
- Department of Natural Sciences, CUNY Baruch College, New York, NY, USA
| | - Csaba Konrad
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Gloria Palomo
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Kirsten Bredvik
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Meri Gerges
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Federica Valsecchi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | | | - John M Ravits
- Department of Neuroscience, University of California San Diego, La Jolla, CA, USA
| | - Anatoly Starkov
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 East 61st Street, RR507, New York, NY, 10065, USA.
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12
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Salling HK, Bang-Christensen SR. Multi-primer qPCR assay capable of highly efficient and specific detection of the vast majority of all known Mycoplasma. Biologicals 2016; 44:129-38. [PMID: 27067447 DOI: 10.1016/j.biologicals.2016.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 02/27/2016] [Accepted: 03/05/2016] [Indexed: 10/22/2022] Open
Abstract
Mycoplasma bacteria are able to pass through sterilizing grade filters due to their small size and lack of a cell wall, making them a common contaminant of biopharmaceutical productions. The classical method for detecting Mycoplasma is described in the European Pharmacopeia (Ph.Eur) 2.6.7. The method takes 28 days to perform, due to the slow growing nature of some Mycoplasma species. The Ph.Eur has described Nucleic Acid Testing (NAT) as a rapid alternative to the classical method. Here we present the development of a quantitative polymerase chain reaction (qPCR) assay capable of unambiguous detection of Mycoplasma with high sensitivity and specificity. The broadness of detection and the specificity towards Mycoplasma has been investigated by in silico analysis of the primer sequences followed by testing on purified Mycoplasma DNA as well as DNA from closely related genera. The assay will in all probability detect at least 356 species and strains of Mycoplasma, Spiroplasma and Acholeplasma with high sensitivity. To our knowledge this assay has the most uniform amplification efficiency over the broadest range of species and it is extremely specific towards Mycoplasma. With appropriate validation, the assay can be applied as a powerful tool for rapid Mycoplasma detection in the biopharmaceutical industry.
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Affiliation(s)
- H K Salling
- Novo Nordisk A/S, Biopharm Purification Development & Virology, Hagedornsvej 1, 2820 Gentofte, Denmark.
| | - S R Bang-Christensen
- Novo Nordisk A/S, Biopharm Purification Development & Virology, Hagedornsvej 1, 2820 Gentofte, Denmark
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World Health Organization International Standard To Harmonize Assays for Detection of Mycoplasma DNA. Appl Environ Microbiol 2015; 81:5694-702. [PMID: 26070671 DOI: 10.1128/aem.01150-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 06/03/2015] [Indexed: 11/20/2022] Open
Abstract
Nucleic acid amplification technique (NAT)-based assays (referred to here as NAT assays) are increasingly used as an alternative to culture-based approaches for the detection of mycoplasma contamination of cell cultures. Assay features, like the limit of detection or quantification, vary widely between different mycoplasma NAT assays. Biological reference materials may be useful for harmonization of mycoplasma NAT assays. An international feasibility study included lyophilized preparations of four distantly related mycoplasma species (Acholeplasma laidlawii, Mycoplasma fermentans, M. orale, M. pneumoniae) at different concentrations which were analyzed by 21 laboratories using 26 NAT assays with a qualitative, semiquantitative, or quantitative design. An M. fermentans preparation was shown to decrease the interassay variation when used as a common reference material. The preparation was remanufactured and characterized in a comparability study, and its potency (in NAT-detectable units) across different NATs was determined. The World Health Organization (WHO) Expert Committee on Biological Standardization (ECBS) established this preparation to be the "1st World Health Organization international standard for mycoplasma DNA for nucleic acid amplification technique-based assays designed for generic mycoplasma detection" (WHO Tech Rep Ser 987:42, 2014) with a potency of 200,000 IU/ml. This WHO international standard is now available as a reference preparation for characterization of NAT assays, e.g., for determination of analytic sensitivity, for calibration of quantitative assays in a common unitage, and for defining regulatory requirements in the field of mycoplasma testing.
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Ingebritson A, Gibbs C, Tong C, Srinivas G. A PCR detection method for testing mycoplasma contamination of veterinary vaccines and biological products. Lett Appl Microbiol 2014; 60:174-180. [DOI: 10.1111/lam.12355] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/06/2014] [Accepted: 10/21/2014] [Indexed: 11/29/2022]
Affiliation(s)
- A.L. Ingebritson
- Center for Veterinary Biologics, Veterinary Services, Animal and Plant Health Inspection Service United States Department of Agriculture Ames IA USA
| | - C.P. Gibbs
- Center for Veterinary Biologics, Veterinary Services, Animal and Plant Health Inspection Service United States Department of Agriculture Ames IA USA
| | - C. Tong
- Center for Veterinary Biologics, Veterinary Services, Animal and Plant Health Inspection Service United States Department of Agriculture Ames IA USA
| | - G.B. Srinivas
- Center for Veterinary Biologics, Veterinary Services, Animal and Plant Health Inspection Service United States Department of Agriculture Ames IA USA
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15
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The expression of pluripotency genes and neuronal markers after neurodifferentiation in fibroblasts co-cultured with human umbilical cord blood mononuclear cells. In Vitro Cell Dev Biol Anim 2014; 51:26-35. [DOI: 10.1007/s11626-014-9804-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/23/2014] [Indexed: 11/27/2022]
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Dabrazhynetskaya A, Furtak V, Volokhov D, Beck B, Chizhikov V. Preparation of reference stocks suitable for evaluation of alternative NAT-based mycoplasma detection methods. J Appl Microbiol 2013; 116:100-8. [PMID: 24112653 DOI: 10.1111/jam.12352] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/08/2013] [Accepted: 09/15/2013] [Indexed: 11/29/2022]
Abstract
AIMS The aim of this study was to optimize conditions for preparation and cryopreservation of mycoplasma reference materials suitable to evaluate alternative nucleic acid testing (NAT)-based assays and to compare their limits of detection (LODs) with those of conventional culture-based methods. METHODS AND RESULTS Acholeplasma laidlawii, Mycoplasma gallisepticum and Mycoplasma arginini stocks with low ratios of genomic copies to colony forming units (12, 8 and 4, respectively) harvested in early stationary phases of growth were preserved with different cryoprotective agents (CPAs) under slow (1°C min(-1)), moderate (8°C min(-1)), fast (13°C min(-1)) and 'snapshot' (60°C min(-1)) cooling rates. Depending on mycoplasma species, increasing the cooling rate from slow to snapshot enhanced cell survival up to 5-fold. The addition of 10% (v/v) dimethyl sulfoxide (DMSO) and 15% (v/v) glycerol significantly improved cell survival of all tested strains. Cryoprotected stocks maintained high and stable titres for at least 1 year during storage at -80°C. Sonication of cell cultures prior to cryopreservation enhanced cell dispersion and reduced of GC/CFU ratios. CONCLUSIONS It is feasible to prepare stable reference stocks of cryopreserved mycoplasma cells suitable to reliably compare NAT- and culture-based mycoplasma testing methods. SIGNIFICANCE AND IMPACT OF THE STUDY This study describes experimental results demonstrating the preparation and storage of highly viable and dispersed mycoplasma reference stocks suitable for comparing alternative NAT-and conventional culture-based mycoplasma detection methods.
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Affiliation(s)
- A Dabrazhynetskaya
- Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD, USA
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17
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Collaborative study report: evaluation of the ATCC experimental mycoplasma reference strains panel prepared for comparison of NAT-based and conventional mycoplasma detection methods. Biologicals 2013; 41:377-83. [PMID: 23910092 DOI: 10.1016/j.biologicals.2013.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/27/2013] [Accepted: 07/08/2013] [Indexed: 11/21/2022] Open
Abstract
The main goal of this collaborative study was to evaluate the experimental panel of cryopreserved mycoplasma reference strains recently prepared by the American Type Culture Collection (ATCC(®)) in order to assess the viability and dispersion of cells in the mycoplasma stocks by measuring the ratio between the number of genomic copies (GC) and the number of colony forming units (CFU) in the reference preparations. The employment of microbial reference cultures with low GC/CFU ratios is critical for unbiased and reliable comparison of mycoplasma testing methods based on different methodological approaches, i.e., Nucleic Acid Testing (NAT) and compendial culture-based techniques. The experimental panel included ten different mycoplasma species known to represent potential human and animal pathogens as well as common contaminants of mammalian and avian cell substrates used in research, development, and manufacture of biological products. Fifteen laboratories with expertise in field of mycoplasma titration and quantification of mycoplasmal genomic DNA participated in the study conducted from February to October of 2012. The results of this study demonstrated the feasibility of preparing highly viable and dispersed (possessing low GC/CFU ratios) frozen stocks of mycoplasma reference materials, required for reliable comparison of NAT-based and conventional mycoplasma detection methods.
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Dabrazhynetskaya A, Volokhov D, David S, Ikonomi P, Brewer A, Chang A, Chizhikov V. Preparation of reference strains for validation and comparison of mycoplasma testing methods. J Appl Microbiol 2011; 111:904-14. [DOI: 10.1111/j.1365-2672.2011.05108.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Volokhov DV, Graham LJ, Brorson KA, Chizhikov VE. Mycoplasma testing of cell substrates and biologics: Review of alternative non-microbiological techniques. Mol Cell Probes 2011; 25:69-77. [DOI: 10.1016/j.mcp.2011.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 12/22/2010] [Accepted: 01/04/2011] [Indexed: 11/25/2022]
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20
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Peredeltchouk M, David SAW, Bhattacharya B, Volokhov DV, Chizhikov V. Detection of mycoplasma contamination in cell substrates using reverse transcription-PCR assays. J Appl Microbiol 2010; 110:54-60. [PMID: 20854458 DOI: 10.1111/j.1365-2672.2010.04853.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To assess the limit of detection (LOD) and the feasibility of 16S rRNA-based reverse transcription-PCR (RT-PCR) assays for advanced detection of mycoplasma contamination in cell substrates. MATERIALS AND METHODS The RT-PCR approach is based on detecting the 16S rRNA molecules that, in contrast to genomic bacterial DNA, are represented by multiple copies in mycoplasma cell. The number of 16S rRNA molecules in mycoplasma cells of five species i.e. Mycoplasma arginini, Myc. fermentans, Myc. hyorhinis, Myc. orale and Acholeplasma laidlawii, all known to be frequent cell line contaminants in industrial and research laboratories, was measured using molecular methods. The results of two independently prepared mycoplasma cultures harvested at the stationary phase of their growth showed that the 16S rRNA copy number per cell varied in the range from about 400 to 2000 copies, depending on species, but stayed close between different preparations of one species. The assessment of the LOD of the in-house 16S rRNA-based RT-PCR was performed using samples of MDCK cell culture spiked with different amounts of five aforementioned mycoplasma species. To minimize the bias in methods comparison, the LOD of the RT-PCR assay was expressed in terms of genome equivalents (GEs) and compared with that determined for highly optimized 16S rDNA-based mycoplasma testing methods previously described in scientific literature. CONCLUSIONS The results of the study showed that the in-house 16S rRNA-based RT-PCR assay was able to reliably detect the presence of less than one mycoplasma GE that is at least 10-fold higher of the LOD previously determined for well-optimized 16S rDNA-based assays developed and described by other researchers. SIGNIFICANCE AND IMPACT OF THE STUDY The results of the study showed that rapid RT-PCR methods based on the detection of bacterial 16S rRNA are able to expedite mycoplasma testing of cell cultures (1-2 days vs 28 days) and to ensure the limits of detection comparable to that of currently used culture-based mycoplasma testing methods.
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Affiliation(s)
- M Peredeltchouk
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD 20852, USA
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Shahhosseiny MH, Hosseiny Z, Khoramkhorshid HR, Azari S, Shokrgozar MA. Rapid and sensitive detection of Mollicutes in cell culture by polymerase chain reaction. J Basic Microbiol 2010; 50:171-8. [PMID: 19810046 DOI: 10.1002/jobm.200800174] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Infections with Mollicutes species (such as Mycoplasma, Acholeplasma, and Ureaplasma) can induce a variety of problems in living organisms and laboratory cell cultures. Therefore, it is necessary to establish a routine diagnostic protocol for Mycoplasma infection in order to ensure reliable research results, as well as the safety of commercial biological products. For that purpose a novel PCR-based procedure using specific designed primers complementary to 16S rRNA genome region of mollicute species was evaluated. PCR was optimized and sensitivity and specificity was evaluated by defined cell count concentrations (2-31250 CFU/ml) of different strains of Mycoplasma, Acholeplasma and Ureaplasma. Amplicon (272 bp) was cloned by PCR-cloning and sequenced by dideoxy chain termination. PCR, was found to be able to detect 10 copies of mollicute target DNA. No cross-reactivity with genomic DNA of non-mollicute bacteria or human cell lines was observed. Forty seven human and animal cell lines were evaluated for mollicute contamination. Twenty five cell lines (53%) were correctly identified as contaminated by this molecular approach. The results of this study demonstrated that this PCR-based method is not only fast and reproducible, but also highly sensitive and specific for detecting contaminant mycoplasmas in cell cultures.
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Xu S, Sharma H, Mutharasan R. Sensitive and selective detection of mycoplasma in cell culture samples using cantilever sensors. Biotechnol Bioeng 2010; 105:1069-77. [PMID: 20014143 DOI: 10.1002/bit.22637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this article we report a new biosensor-based method that is more sensitive and rapid than the current approach for detecting mycoplasma in cell culture samples. Piezoelectric-excited millimeter-sized cantilever (PEMC) sensors respond to mass change via resonant frequency change. They are sensitive at femtogram level and can be used directly in liquid for label-free detection. Common cell culture contaminant, Acholeplasma laidlawii was detected in both buffer and cell culture medium. Two different sources (positive control from a commercial kit and ATCC 23206) were analyzed using antibody-immobilized PEMC sensor. Resonant frequency decrease caused by binding of A. laidlawii was monitored in real-time using an impedance analyzer. Positive detection was confirmed by a second antibody binding. The limit of detection (LOD) was lower than 10(3) CFU/mL in cell culture medium using PEMC sensor while parallel ELISA assays showed LOD as 10(7) CFU/mL. This study shows that PEMC sensor can be used for sensitive and rapid mycoplasma detection in cell culture samples.
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Affiliation(s)
- Sen Xu
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA
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Deutschmann SM, Kavermann H, Knack Y. Validation of a NAT-based Mycoplasma assay according European Pharmacopoiea. Biologicals 2010; 38:238-48. [DOI: 10.1016/j.biologicals.2009.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 11/11/2009] [Indexed: 10/19/2022] Open
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Asarnow D, Warford A, Fernandez L, Hom J, Sandhu G, Candichoy Z, Luna G, Goldman M, Rarich R. Validation and international regulatory experience for a mycoplasma touchdown PCR assay. Biologicals 2010; 38:224-31. [DOI: 10.1016/j.biologicals.2009.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 11/09/2009] [Indexed: 11/28/2022] Open
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Zhi Y, Mayhew A, Seng N, Takle GB. Validation of a PCR method for the detection of mycoplasmas according to European Pharmacopoeia section 2.6.7. Biologicals 2010; 38:232-7. [DOI: 10.1016/j.biologicals.2009.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 11/06/2009] [Indexed: 11/27/2022] Open
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Consensus guidance for banking and supply of human embryonic stem cell lines for research purposes. Stem Cell Rev Rep 2010; 5:301-14. [PMID: 20016957 DOI: 10.1007/s12015-009-9085-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
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- The International Stem Cell Banking Initiative, Blanche Lane, Ridge, Herts, UK
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27
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Biological enrichment of Mycoplasma agents by cocultivation with permissive cell cultures. Appl Environ Microbiol 2008; 74:5383-91. [PMID: 18606798 DOI: 10.1128/aem.00720-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we describe our results on the evaluation of the ability of different permissive mammalian cell lines to support the biological enrichment of mycoplasma species known to be bacterial contaminants of cell substrates. The study showed that this approach is able to significantly improve the efficiency of mycoplasma detection based on nucleic acid testing or biochemical technologies (e.g., MycoAlert mycoplasma detection). Of 10 different cell lines (Vero, MDBK, HEK-293, Hep-G2, CV-1, EBTr, WI-38, R9ab, MDCK, and High Five) used in the study, only MDCK cell culture was found to support the efficient growth of all the tested mycoplasmas (Mycoplasma arginini, M. bovis, M. fermentans, M. gallinaceum, M. gallisepticum, M. synoviae, M. hominis, M. hyorhinis, M. orale, M. salivarium, and Acholeplasma laidlawii) known to be most frequently associated with contamination of cell substrates and cell lines in research laboratories or manufacturing facilities. The infection of MDCK cells with serial dilutions of each mycoplasma species demonstrated that these common cell line contaminants can be detected reliably after 7-day enrichment in MDCK cell culture at contamination levels of 0.05 to 0.25 CFU/ml. The High Five insect cell line was also found to be able to support the efficient growth of most mycoplasma species tested, except for M. hyorhinis strain DBS1050. However, mycoplasma growth in insect cell culture was demonstrated to be temperature dependent, and the most efficient growth was observed when the incubation temperature was increased from 28 degrees C to between 35 and 37 degrees C. We believe that this type of mycoplasma enrichment is one of the most promising approaches for improving the purity and safety testing of cell substrates and other cell-derived biologics and pharmaceuticals.
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Beqaj SH, Flesher R, Walker GR, Smith SA. Use of the real-time PCR assay in conjunction with MagNA Pure for the detection of mycobacterial DNA from fixed specimens. ACTA ACUST UNITED AC 2007; 16:169-73. [PMID: 17721325 DOI: 10.1097/pdm.0b013e318037552e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Tuberculosis in immunocompromised patients is often caused by Mycobacterial species other than Mycobacterium tuberculosis. Thus, detection of and differentiation between M. tuberculosis and nontuberculosis species is necessary for diagnosis of disease in these patients. Furthermore, when tissue changes show granulomatous inflammation, quick confirmation testing for mycobacterial infection is needed for conclusive diagnosis. The aim of this study was to validate the utility of a real-time polymerase chain reaction (PCR) assay in conjunction with the MagNA Pure LC automated extraction system for the detection of mycobacterial DNA from formalin-fixed, paraffin-embedded specimens. A total of 46 archived, paraffin-embedded, fixed specimens showing granulomatous inflammation were studied for mycobacterial infection by real-time PCR. Bacterial DNA was extracted and isolated using the MagNA Pure extraction system. Real-time PCR was performed on the LightCycler using the Artus Real Art Mycob Diff ASR kit from Qiagen. Thirteen of the 46 patient specimens were positive for mycobacterial infection by acid-fast bacilli (AFB) stain. Of the13 reported positive by AFB stain, 12 where positive by real-time PCR. All 13 specimens reported positive by AFB were sent for culture confirmation. Eleven of 13 were returned positive by culture. Specimens reported as negative by culture and positive by real-time PCR were confirmed positive by a second PCR method from another reference laboratory. We believe that these studies are beneficial in the differential diagnosis of mycobacterial infection from fixed tissue specimens where tuberculosis might not have been clinically initially suspected and when specimens are not suitable for microbiologic examination.
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Kong H, Volokhov DV, George J, Ikonomi P, Chandler D, Anderson C, Chizhikov V. Application of cell culture enrichment for improving the sensitivity of mycoplasma detection methods based on nucleic acid amplification technology (NAT). Appl Microbiol Biotechnol 2007; 77:223-32. [PMID: 17717660 DOI: 10.1007/s00253-007-1135-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 07/18/2007] [Accepted: 07/26/2007] [Indexed: 10/22/2022]
Abstract
Herein, we present data demonstrating that the application of initial cell culture enrichment could significantly improve mycoplasma testing methods based on the nucleic acid amplification technology (NAT) including a polymerase chain reaction (PCR)/microarray method. The results of the study using Vero cells demonstrated that this cell culture is able (1) to support efficient growth of mycoplasmas of primary interest, i.e., species found to be cell line contaminants, (2) to increase the sensitivity of NAT assay to the detection limits of the conventional broth/agar culture methods, and (3) to reduce the time required for mycoplasma testing fourfold in comparison with the conventional methods. Detection and identification of mycoplasmal agents were conducted using a modified PCR/microarray assay based on genetic differences among Mollicutes in the 16S-23S rRNA intergenic transcribed spacer (ITS). The application of nano-gold/silver enhancement technology instead of previously used fluorescent dyes significantly simplified the readout of microarray results and allowed us to avoid using expensive scanning equipment. This modification has the potential to expand the implementation of microarray techniques into laboratories involved in diagnostic testing of mycoplasma contamination in cell substrates and potentially in other biological and pharmaceutical products.
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Affiliation(s)
- Hyesuk Kong
- Center for Biologics Evaluation and Research, Food and Drug Administration, 1401 Rockville Pike, HFM-470, Rockville, MD 20852, USA
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Cheng HS, Shen CW, Wang SR. Effect of storage conditions on detection of mycoplasma in biopharmaceutical products. In Vitro Cell Dev Biol Anim 2007; 43:113-9. [PMID: 17554591 DOI: 10.1007/s11626-007-9015-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 02/02/2007] [Indexed: 10/23/2022]
Abstract
Mycoplasma contamination affects many different aspects of cell culturing, resulting in unreliable experimental results and potentially harmful biological products. Therefore, the specificity, sensitivity, and reliability of detecting mycoplasma contamination are important aspects of quality control in biotechnological products. In this study, Mycoplasma hyorhinis was adopted as a model strain to evaluate the effects of storage on the viability of Mycoplasma species in cell culture samples. Medium X was compared with conventional media 243 and 988 for the ability to detect M. hyorhinis. The 10(1) CFU/ml of M. hyorhinis was inoculated into medium X prepared using the same lots of components and preserved for 7 d, 1 mo, and 2 mo. M. hyorhinis grew readily and typically on agar plates prepared within 1 mo. The viable mycoplasmas in samples containing different initial titers (10(1) and 10(6) CFU/ml) after storage at 4 degrees C and -30 degrees C were analyzed. During storage, viable organisms were found with little or no reduction in titers after storage for 8 wk at -30 degrees C under aerobic and anaerobic conditions. A reduction in titers of 3 log10 occurred after 4 wk storage for high-dose cultures (10(6) CFU/ml) at 4 degrees C. The titers of viable organisms were diminished over 8 wk at 4 degrees C under aerobic and anaerobic conditions.
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Affiliation(s)
- Hsiu-Shuei Cheng
- Division of Biotechnology, Animal Technology Institute Taiwan, Taiwan, Republic of China.
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31
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Mason C, Hoare M. Regenerative Medicine Bioprocessing: Building a Conceptual Framework Based on Early Studies. ACTA ACUST UNITED AC 2007; 13:301-11. [PMID: 17518564 DOI: 10.1089/ten.2006.0177] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This paper reviews early studies of regenerative medicine using human cells and engineered tissues progressing from a laboratory-centered manual procedure toward automated manufacture. It then examines the distinctive bioprocesses by which autologous human material must be produced, the degree of simplification allowed by use of allogeneic cell lines and engineered tissue derived from them, and issues that affect both cell types. The paper concludes by drawing upon this discussion to suggest some factors that will determine how regenerative medicine bioprocessing can progress to provide many units of material economically.
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Affiliation(s)
- Chris Mason
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, London, United Kingdom.
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