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Sarfraz A, Wara TU, Sheheryar, Chen K, Ansari SH, Zaman A, Nishan U, Iqbal A, Ullah R, Ali EA, Shah M, Ojha SC. Structural informatics approach for designing an epitope-based vaccine against the brain-eating Naegleria fowleri. Front Immunol 2023; 14:1284621. [PMID: 37965306 PMCID: PMC10642955 DOI: 10.3389/fimmu.2023.1284621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/16/2023] [Indexed: 11/16/2023] Open
Abstract
Primary Amoebic Meningoencephalitis (PAM), a severe lethal brain disease, is caused by a parasite, Naegleria fowleri, also known as the "brain-eating amoeba". The chances of a patient's recovery after being affected by this parasite are very low. Only 5% of people are known to survive this life-threatening infection. Despite the fact that N. fowleri causes a severe, fatal infection, there is no proper treatment available to prevent or cure it. In this context, it is necessary to formulate a potential vaccine that could be able to combat N. fowleri infection. The current study aimed at developing a multi-epitope subunit vaccine against N. fowleri by utilizing immunoinformatics techniques and reverse vaccinology approaches. The T- and B-cell epitopes were predicted by various tools. In order to choose epitopes with the ability to trigger both T- and B-cell-mediated immune responses, the epitopes were put through a screening pipeline including toxicity, antigenicity, cytokine-inductivity, and allergenicity analysis. Three vaccine constructs were designed from the generated epitopes linked with linkers and adjuvants. The modeled vaccines were docked with the immune receptors, where vaccine-1 showed the highest binding affinity. Binding affinity and stability of the docked complex were confirmed through normal mode analysis and molecular dynamic simulations. Immune simulations developed the immune profile, and in silico cloning affirmed the expression probability of the vaccine construct in Escherichia coli (E. coli) strain K12. This study demonstrates an innovative preventative strategy for the brain-eating amoeba by developing a potential vaccine through immunoinformatics and reverse vaccinology approaches. This study has great preventive potential for Primary Amoebic Meningoencephalitis, and further research is required to assess the efficacy of the designed vaccine.
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Affiliation(s)
- Asifa Sarfraz
- Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan
| | - Tehreem Ul Wara
- Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan
| | - Sheheryar
- Department of Biochemistry and Molecular Biology, Federal University of Ceara, Fortaleza, Brazil
| | - Ke Chen
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, China
| | | | - Aqal Zaman
- Department of Microbiology & Molecular Genetics, Bahauddin Zakariya University, Multan, Pakistan
| | - Umar Nishan
- Department of Chemistry, Kohat University of Science & Technology, Kohat, Pakistan
| | - Anwar Iqbal
- Department of Chemical Sciences, University of Lakki Marwat, Khyber Pakhtunkhwa, Pakistan
| | - Riaz Ullah
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Essam A. Ali
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohibullah Shah
- Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan
| | - Suvash Chandra Ojha
- Department of Infectious Diseases, The Affiliated Hospital of Southwest Medical University, Luzhou, China
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Various brain-eating amoebae: the protozoa, the pathogenesis, and the disease. Front Med 2021; 15:842-866. [PMID: 34825341 DOI: 10.1007/s11684-021-0865-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/25/2021] [Indexed: 10/19/2022]
Abstract
Among various genera of free-living amoebae prevalent in nature, some members are identified as causative agents of human encephalitis, in which Naegleria fowleri followed by Acanthamoeba spp. and Balamuthia mandrillaris have been successively discovered. As the three dominant genera responsible for infections, Acanthamoeba and Balamuthia work as opportunistic pathogens of granulomatous amoebic encephalitis in immunocompetent and immunocompromised individuals, whereas Naegleria induces primary amoebic meningoencephalitis mostly in healthy children and young adults as a more violent and deadly disease. Due to the lack of typical symptoms and laboratory findings, all these amoebic encephalitic diseases are difficult to diagnose. Considering that subsequent therapies are also affected, all these brain infections cause significant mortality worldwide, with more than 90% of the cases being fatal. Along with global warming and population explosion, expanding areas of human and amoebae activity in some regions lead to increased contact, resulting in more serious infections and drawing increased public attention. In this review, we summarize the present information of these pathogenic free-living amoebae, including their phylogeny, classification, biology, and ecology. The mechanisms of pathogenesis, immunology, pathophysiology, clinical manifestations, epidemiology, diagnosis, and therapies are also discussed.
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Lee YA, Kim KA, Shin MH. Naegleria fowleri Induces Jurkat T Cell Death via O-deGlcNAcylation. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:501-505. [PMID: 34724770 PMCID: PMC8561043 DOI: 10.3347/kjp.2021.59.5.501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/17/2021] [Indexed: 11/23/2022]
Abstract
The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri-induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.
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Affiliation(s)
- Young Ah Lee
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Kyeong Ah Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Myeong Heon Shin
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul 03722, Korea
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Güémez A, García E. Primary Amoebic Meningoencephalitis by Naegleria fowleri: Pathogenesis and Treatments. Biomolecules 2021; 11:biom11091320. [PMID: 34572533 PMCID: PMC8469197 DOI: 10.3390/biom11091320] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/29/2022] Open
Abstract
Naegleria fowleri is a free-living amoeba (FLA) that is commonly known as the "brain-eating amoeba." This parasite can invade the central nervous system (CNS), causing an acute and fulminating infection known as primary amoebic meningoencephalitis (PAM). Even though PAM is characterized by low morbidity, it has shown a mortality rate of 98%, usually causing death in less than two weeks after the initial exposure. This review summarizes the most recent information about N. fowleri, its pathogenic molecular mechanisms, and the neuropathological processes implicated. Additionally, this review includes the main therapeutic strategies described in case reports and preclinical studies, including the possible use of immunomodulatory agents to decrease neurological damage.
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Herman EK, Greninger A, van der Giezen M, Ginger ML, Ramirez-Macias I, Miller HC, Morgan MJ, Tsaousis AD, Velle K, Vargová R, Záhonová K, Najle SR, MacIntyre G, Muller N, Wittwer M, Zysset-Burri DC, Eliáš M, Slamovits CH, Weirauch MT, Fritz-Laylin L, Marciano-Cabral F, Puzon GJ, Walsh T, Chiu C, Dacks JB. Genomics and transcriptomics yields a system-level view of the biology of the pathogen Naegleria fowleri. BMC Biol 2021; 19:142. [PMID: 34294116 PMCID: PMC8296547 DOI: 10.1186/s12915-021-01078-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 06/24/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The opportunistic pathogen Naegleria fowleri establishes infection in the human brain, killing almost invariably within 2 weeks. The amoeba performs piece-meal ingestion, or trogocytosis, of brain material causing direct tissue damage and massive inflammation. The cellular basis distinguishing N. fowleri from other Naegleria species, which are all non-pathogenic, is not known. Yet, with the geographic range of N. fowleri advancing, potentially due to climate change, understanding how this pathogen invades and kills is both important and timely. RESULTS Here, we report an -omics approach to understanding N. fowleri biology and infection at the system level. We sequenced two new strains of N. fowleri and performed a transcriptomic analysis of low- versus high-pathogenicity N. fowleri cultured in a mouse infection model. Comparative analysis provides an in-depth assessment of encoded protein complement between strains, finding high conservation. Molecular evolutionary analyses of multiple diverse cellular systems demonstrate that the N. fowleri genome encodes a similarly complete cellular repertoire to that found in free-living N. gruberi. From transcriptomics, neither stress responses nor traits conferred from lateral gene transfer are suggested as critical for pathogenicity. By contrast, cellular systems such as proteases, lysosomal machinery, and motility, together with metabolic reprogramming and novel N. fowleri proteins, are all implicated in facilitating pathogenicity within the host. Upregulation in mouse-passaged N. fowleri of genes associated with glutamate metabolism and ammonia transport suggests adaptation to available carbon sources in the central nervous system. CONCLUSIONS In-depth analysis of Naegleria genomes and transcriptomes provides a model of cellular systems involved in opportunistic pathogenicity, uncovering new angles to understanding the biology of a rare but highly fatal pathogen.
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Affiliation(s)
- Emily K Herman
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
| | - Alex Greninger
- Laboratory Medicine and Medicine / Infectious Diseases, UCSF-Abbott Viral Diagnostics and Discovery Center, UCSF Clinical Microbiology Laboratory UCSF School of Medicine, San Francisco, USA
- Department of Laboratory Medicine, University of Washington Medical Center, Montlake, USA
| | - Mark van der Giezen
- Centre for Organelle Research, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway
| | - Michael L Ginger
- School of Applied Sciences, Department of Biological and Geographical Sciences, University of Huddersfield, Huddersfield, UK
| | - Inmaculada Ramirez-Macias
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Department of Cardiology, Hospital Clinico Universitario Virgen de la Arrixaca. Instituto Murciano de Investigación Biosanitaria. Centro de Investigación Biomedica en Red-Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Haylea C Miller
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No.5, Wembley, Western Australia 6913, Australia
- CSIRO, Indian Oceans Marine Research Centre, Environomics Future Science Platform, Crawley, WA, Australia
| | - Matthew J Morgan
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | | | - Katrina Velle
- Department of Biology, University of Massachusetts, Amherst, UK
| | - Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Kristína Záhonová
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Sebastian Rodrigo Najle
- Institut de Biologia Evolutiva (UPF-CSIC), Barcelona, Spain
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), 08003, Barcelona, Catalonia, Spain
| | - Georgina MacIntyre
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Norbert Muller
- Institute of Parasitology, Vetsuisse Faculty Bern, University of Bern, Bern, Switzerland
| | - Mattias Wittwer
- Spiez Laboratory, Federal Office for Civil Protection, Austrasse, Spiez, Switzerland
| | - Denise C Zysset-Burri
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Claudio H Slamovits
- Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Canada
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology and Divisions of Biomedical Informatics and Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, USA
| | | | - Francine Marciano-Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
| | - Geoffrey J Puzon
- CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag No.5, Wembley, Western Australia 6913, Australia
| | - Tom Walsh
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | - Charles Chiu
- Laboratory Medicine and Medicine / Infectious Diseases, UCSF-Abbott Viral Diagnostics and Discovery Center, UCSF Clinical Microbiology Laboratory UCSF School of Medicine, San Francisco, USA
| | - Joel B Dacks
- Division of Infectious Disease, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada.
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
- Department of Life Sciences, The Natural History Museum, London, UK.
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6
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Maciver SK, McLaughlin PJ, Apps DK, Piñero JE, Lorenzo-Morales J. Opinion: Iron, Climate Change and the ‘Brain Eating Amoeba’ Naegleria fowleri. Protist 2021. [DOI: 10.1016/j.protis.2020.125791] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gutiérrez-Sánchez M, Carrasco-Yepez MM, Herrera-Díaz J, Rojas-Hernández S. Identification of differential protein recognition pattern between Naegleria fowleri and Naegleria lovaniensis. Parasite Immunol 2020; 42:e12715. [PMID: 32191816 DOI: 10.1111/pim.12715] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/05/2020] [Accepted: 03/13/2020] [Indexed: 12/15/2022]
Abstract
Many pathogenicity factors are involved in the development of primary amoebic meningoencephalitis (PAM) caused by N fowleri. However, most of them are not exclusive for N fowleri and they have not even been described in other nonpathogenic Naegleria species. Therefore, the objective of this work was to identify differential proteins and protein pattern recognition between Naegleria fowleri and Naegleria lovaniensis using antibodies anti-N fowleri as strategy to find vaccine candidates against meningoencephalitis. Electrophoresis and Western blots conventional and 2-DE were performed for the identification of antigenic proteins, and these were analysed by the mass spectrometry technique. The results obtained in 2-DE gels and Western blot showed very notable differences in spot intensity between these two species, specifically those with relative molecular weight of 100, 75, 50 and 19 kDa. Some spots corresponding to these molecular weights were identified as actin fragment, myosin II, heat shock protein, membrane protein Mp2CL5 among others, with differences in theoretical post-translational modifications. In this work, we found differences in antigenic proteins between both species, proteins that could be used for a further development of vaccines against N fowleri infection.
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Affiliation(s)
- Mara Gutiérrez-Sánchez
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, Mexico
| | - Maria Maricela Carrasco-Yepez
- Laboratorio de Microbiología, Grupo CyMA, Unidad de Investigación Interdisciplinaria en Ciencias de la Salud y la Educación, Universidad Nacional Autónoma de México, UNAM FES Iztacala, Tlalnepantla, Mexico
| | - Jorge Herrera-Díaz
- Unidad de Servicios de Apoyo a la Investigación y la Industria, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Saul Rojas-Hernández
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, Mexico
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Thái TL, Kang JM, Lê HG, Lee J, Yoo WG, Shin HJ, Sohn WM, Na BK. Fowlerstefin, a cysteine protease inhibitor of Naegleria fowleri, induces inflammatory responses in BV-2 microglial cells in vitro. Parasit Vectors 2020; 13:41. [PMID: 31996242 PMCID: PMC6988287 DOI: 10.1186/s13071-020-3909-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 01/15/2020] [Indexed: 01/30/2023] Open
Abstract
Background Naegleria fowleri is a free-living amoeba that causes an opportunistic fatal infection known as primary amoebic meningoencephalitis (PAM) in humans. Cysteine proteases produced by the amoeba may play critical roles in the pathogenesis of infection. In this study, a novel cysteine protease inhibitor of N. fowleri (fowlerstefin) was characterized to elucidate its biological function as an endogenous cysteine protease inhibitor of the parasite as well as a pathogenic molecule that induces immune responses in microglial cells. Methods Recombinant fowlerstefin was expressed in Escherichia coli. The inhibitory activity of fowlerstefin against several cysteine proteases, including human cathepsins B and L, papain and NfCPB-L, was analyzed. Fowlerstefin-induced pro-inflammatory response in BV-2 microglial cells was anayzed by cytokine array assay, reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay. Results Fowlerstefin is a cysteine protease inhibitor with a monomeric structure, and belongs to the stefin family. Recombinant fowlerstefin effectively inhibited diverse cysteine proteases including cathepsin B-like cysteine proteases of N. fowleri (NfCPB-L), human cathepsins B and L, and papain. Expression of fowlerstefin in the amoeba was optimal during the trophozoite stage and gradually decreased in cysts. Fowlerstefin induced an inflammatory response in BV-2 microglial cells. Fowlerstefin induced the expression of several pro-inflammatory cytokines and chemokines including IL-6 and TNF in BV-2 microglial cells. Fowlerstefin-induced expression of IL-6 and TNF in BV-2 microglial cells was regulated by mitogen-activated protein kinase (MAPKs). The inflammatory response induced by fowlerstefin in BV-2 microglial cells was downregulated via inhibition of NF-κB and AP-1. Conclusions Fowlerstefin is a pathogenic molecule that stimulates BV-2 microglial cells to produce pro-inflammatory cytokines through NF-κB- and AP-1-dependent MAPK signaling pathways. Fowlerstefin-induced inflammatory cytokines exacerbate the inflammatory response in N. fowleri-infected areas and contribute to the pathogenesis of PAM.
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Affiliation(s)
- Thị Lam Thái
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Hương Giang Lê
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea
| | - Jinyoung Lee
- Department of Tropical Medicine and Inha Research Institute for Medical Sciences, Inha University School of Medicine, Incheon, 22212, Republic of Korea
| | - Won Gi Yoo
- Department of Medical Environmental Biology, Chung-Ang University College of Medicine, Seoul, 06974, Republic of Korea
| | - Ho-Joon Shin
- Department of Microbiology, Ajou University School of Medicine, Suwon, 16499, Republic of Korea.,Department of Biomedical Science, Ajou University School of Medicine, Suwon, 16499, Republic of Korea
| | - Woon-Mok Sohn
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 52727, Republic of Korea. .,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Republic of Korea.
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Betanzos A, Bañuelos C, Orozco E. Host Invasion by Pathogenic Amoebae: Epithelial Disruption by Parasite Proteins. Genes (Basel) 2019; 10:E618. [PMID: 31416298 PMCID: PMC6723116 DOI: 10.3390/genes10080618] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/25/2019] [Accepted: 04/29/2019] [Indexed: 02/07/2023] Open
Abstract
The epithelium represents the first and most extensive line of defence against pathogens, toxins and pollutant agents in humans. In general, pathogens have developed strategies to overcome this barrier and use it as an entrance to the organism. Entamoeba histolytica, Naegleriafowleri and Acanthamoeba spp. are amoebae mainly responsible for intestinal dysentery, meningoencephalitis and keratitis, respectively. These amoebae cause significant morbidity and mortality rates. Thus, the identification, characterization and validation of molecules participating in host-parasite interactions can provide attractive targets to timely intervene disease progress. In this work, we present a compendium of the parasite adhesins, lectins, proteases, hydrolases, kinases, and others, that participate in key pathogenic events. Special focus is made for the analysis of assorted molecules and mechanisms involved in the interaction of the parasites with epithelial surface receptors, changes in epithelial junctional markers, implications on the barrier function, among others. This review allows the assessment of initial host-pathogen interaction, to correlate it to the potential of parasite invasion.
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Affiliation(s)
- Abigail Betanzos
- Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexico City 03940, Mexico
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City 07360, Mexico
| | - Cecilia Bañuelos
- Coordinación General de Programas de Posgrado Multidisciplinarios, Programa de Doctorado Transdisciplinario en Desarrollo Científico y Tecnológico para la Sociedad, CINVESTAV-IPN, Mexico City 07360, Mexico
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN, Mexico City 07360, Mexico.
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10
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Sohn HJ, Song KJ, Kang H, Ham AJ, Lee JH, Chwae YJ, Kim K, Park S, Kim JH, Shin HJ. Cellular characterization of actin gene concerned with contact-dependent mechanisms in Naegleria fowleri. Parasite Immunol 2019; 41:e12631. [PMID: 31077592 DOI: 10.1111/pim.12631] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/20/2022]
Abstract
Free-living amoeba, Naegleria fowleri, destroys target cells through contact-dependent mechanisms, such as phagocytosis and/or trogocytosis. A previous experiment showed that the nf-actin gene consisted of 1.2 kbp, produced a 50.1 kDa recombinant protein (Nf-actin), and was localized on the cytoskeleton, pseudopodia and amoebastome. In this study, cellular characterization of the nf-actin gene concerned with contact-dependent mechanisms in N fowleri was performed. The nf-actin gene was amplified from a gene-cloned vector, pEXQP5-T7/NT TOPO. The nf-actin gene was introduced into the Ubi-pEGFP-C2 vector, and Ubi-pEGFP-C2/nf-actin was transfected into N fowleri trophozoites. Strong GFP fluorescence was detected in N fowleri trophozoites transfected with Ubi-pEGFP-C2/nf-actin. Expression of EGFP-Nf-actin protein was detected by Western blot analysis. The nf-actin-overexpressing N fowleri showed significantly increased adhesion activity against extracellular matrix components, fibronectin, collagen I and fibrinogen, compared with wild-type N fowleri. Moreover, nf-actin-overexpressing N fowleri showed increased phagocytic activity and cytotoxicity in comparison with wild-type N fowleri. In summary, the overexpressed nf-actin gene has an important function in ability to increase cell adhesion, cytotoxicity and phagocytosis by N fowleri.
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Affiliation(s)
- Hae-Jin Sohn
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | | | - Heekyoung Kang
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - A-Jeong Ham
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - Jae-Ho Lee
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - Yong-Joon Chwae
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - Kyongmin Kim
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - Sun Park
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
| | - Jong-Hyun Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju, Korea
| | - Ho-Joon Shin
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea.,Department of Biomedical Science, Graduate School of Ajou University, Suwon, Korea
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Samba-Louaka A, Delafont V, Rodier MH, Cateau E, Héchard Y. Free-living amoebae and squatters in the wild: ecological and molecular features. FEMS Microbiol Rev 2019; 43:415-434. [DOI: 10.1093/femsre/fuz011] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/30/2019] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Free-living amoebae are protists frequently found in water and soils. They feed on other microorganisms, mainly bacteria, and digest them through phagocytosis. It is accepted that these amoebae play an important role in the microbial ecology of these environments. There is a renewed interest for the free-living amoebae since the discovery of pathogenic bacteria that can resist phagocytosis and of giant viruses, underlying that amoebae might play a role in the evolution of other microorganisms, including several human pathogens. Recent advances, using molecular methods, allow to bring together new information about free-living amoebae. This review aims to provide a comprehensive overview of the newly gathered insights into (1) the free-living amoeba diversity, assessed with molecular tools, (2) the gene functions described to decipher the biology of the amoebae and (3) their interactions with other microorganisms in the environment.
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Affiliation(s)
- Ascel Samba-Louaka
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Vincent Delafont
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
| | - Marie-Hélène Rodier
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Estelle Cateau
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
- Laboratoire de Parasitologie et Mycologie, CHU La Milétrie, 2 rue de la Milétrie, 86021 Poitiers Cedex, France
| | - Yann Héchard
- Laboratoire Ecologie et Biologie des Interactions (EBI), Equipe Microbiologie de l'Eau, Université de Poitiers, UMR CNRS 7267, 1 rue Georges Bonnet, TSA51106, 86073 POITIERS Cedex 9, France
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Affiliation(s)
- Mohammad Ridwane Mungroo
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway, Malaysia
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway, Malaysia
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13
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Carrasco-Yepez MM, Contis-Montes de Oca A, Campos-Rodriguez R, Falcon-Acosta D, Pacheco-Yepez J, Rodriguez-Mera IB, Bonilla-Lemus P, Rosales-Cruz E, Lopez-Reyes I, Rojas-Hernandez S. Mouse neutrophils release extracellular traps in response to Naegleria fowleri. Parasite Immunol 2019; 41:e12610. [PMID: 30525201 DOI: 10.1111/pim.12610] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 11/27/2018] [Indexed: 01/09/2023]
Abstract
Naegleria fowleri is a free-living amoeba, which is able to infect humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. These structures represent an important strategy to immobilize and kill invading microorganisms. In this work, we evaluate the capacity of N fowleri to induce the NETs release by PMNs cells in mice in vitro and in vivo. In vitro: Neutrophils from bone marrow were cocultured with N fowleri trophozoites. In vivo: we employed a mouse model of PAM. We evaluated DNA, histone and myeloperoxidase (MPO) and the formation of NETs by confocal microscopy. Our results showed N fowleri induce both NETs and MPO release by PMNs cells in mice after trophozoite exposure, which increased through time, in vitro and in vivo. These results demonstrate that NETs are somehow associated with the amoebas. We suggest PMNs release their traps trying to avoid N fowleri attachment at the apical side of the nasal epithelium.
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Affiliation(s)
| | - Arturo Contis-Montes de Oca
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
| | - Rafael Campos-Rodriguez
- Laboratorio de Bioquímica, Departamento de Bioquímica, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
| | - Diana Falcon-Acosta
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
| | - Judith Pacheco-Yepez
- Laboratorio de Bioquímica, Departamento de Bioquímica, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
| | - Itzel Berenice Rodriguez-Mera
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
| | - Patricia Bonilla-Lemus
- Laboratorio de Microbiología, Proyecto CyMA, UIICSE, UNAM FES Iztacala, Tlalnepantla, México
| | - Erika Rosales-Cruz
- Laboratorio de Investigación en Hematopatología, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, México City, México
| | - Israel Lopez-Reyes
- Universidad de la Ciudad de México, Plantel Cuautepec, Mexico City, Mexico
| | - Saul Rojas-Hernandez
- Laboratorio de Inmunobiología Molecular y Celular, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, México
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Seong GS, Sohn HJ, Kang H, Seo GE, Kim JH, Shin HJ. Production and characterization of monoclonal antibodies against cathepsin B and cathepsin B-Like proteins of Naegleria fowleri. Exp Parasitol 2017; 183:171-177. [DOI: 10.1016/j.exppara.2017.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 08/18/2017] [Accepted: 09/11/2017] [Indexed: 11/15/2022]
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15
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Siddiqui R, Ali IKM, Cope JR, Khan NA. Biology and pathogenesis of Naegleria fowleri. Acta Trop 2016; 164:375-394. [PMID: 27616699 DOI: 10.1016/j.actatropica.2016.09.009] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/06/2016] [Accepted: 09/06/2016] [Indexed: 12/13/2022]
Abstract
Naegleria fowleri is a protist pathogen that can cause lethal brain infection. Despite decades of research, the mortality rate related with primary amoebic meningoencephalitis owing to N. fowleri remains more than 90%. The amoebae pass through the nose to enter the central nervous system killing the host within days, making it one of the deadliest opportunistic parasites. Accordingly, we present an up to date review of the biology and pathogenesis of N. fowleri and discuss needs for future research against this fatal infection.
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Kang H, Seong GS, Sohn HJ, Kim JH, Lee SE, Park MY, Lee WJ, Shin HJ. Effective PCR-based detection of Naegleria fowleri from cultured sample and PAM-developed mouse. Eur J Protistol 2015; 51:401-8. [PMID: 26322498 DOI: 10.1016/j.ejop.2015.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
Increasing numbers of Primary Amoebic Meningoencephalitis (PAM) cases due to Naegleria fowleri are becoming a serious issue in subtropical and tropical countries as a Neglected Tropical Disease (NTD). To establish a rapid and effective diagnostic tool, a PCR-based detection technique was developed based on previous PCR methods. Four kinds of primer pairs, Nfa1, Nae3, Nf-ITS, and Naegl, were employed in the cultured amoebic trophozoites and a mouse with PAM experimentally developed by N. fowleri inoculation (PAM-mouse). For the extraction of genomic DNA from N. fowleri trophozoites (1×10(6)), simple boiling with 10μl of PBS (pH 7.4) at 100°C for 30min was found to be the most rapid and efficient procedure, allowing amplification of 2.5×10(2) trophozoites using the Nfa-1 primer. The primers Nfa1 and Nae3 amplified only N. fowleri DNA, whereas the ITS primer detected N. fowleri and N. gruberi DNA. Using the PAM-mouse brain tissue, the Nfa1 primer was able to amplify the N. fowleri DNA 4 days post infection with 1ng/μl of genomic DNA being detectable. Using the PAM-mouse CSF, amplification of the N. fowleri DNA with the Nae3 primer was possible 5 days post infection showing a better performance than the Nfa1 primer at day 6.
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Affiliation(s)
- Heekyoung Kang
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea; Department of Biomedical Science, Graduate School of Ajou University, Suwon 443-721, Republic of Korea
| | - Gi-Sang Seong
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea; Department of Biomedical Science, Graduate School of Ajou University, Suwon 443-721, Republic of Korea
| | - Hae-Jin Sohn
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea; Department of Biomedical Science, Graduate School of Ajou University, Suwon 443-721, Republic of Korea
| | - Jong-Hyun Kim
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Sang-Eun Lee
- Division of Malaria and Parasitic Disease, Korea National Institute of Health, Osong 363-951, Republic of Korea
| | - Mi Yeoun Park
- Division of Malaria and Parasitic Disease, Korea National Institute of Health, Osong 363-951, Republic of Korea
| | - Won-Ja Lee
- Division of Malaria and Parasitic Disease, Korea National Institute of Health, Osong 363-951, Republic of Korea
| | - Ho-Joon Shin
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea; Department of Biomedical Science, Graduate School of Ajou University, Suwon 443-721, Republic of Korea.
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17
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Lee J, Yoo JK, Sohn HJ, Kang HK, Kim D, Shin HJ, Kim JH. Protective immunity against Naegleria fowleri infection on mice immunized with the rNfa1 protein using mucosal adjuvants. Parasitol Res 2015; 114:1377-85. [PMID: 25604672 DOI: 10.1007/s00436-015-4316-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/07/2015] [Indexed: 12/17/2022]
Abstract
The free-living amoeba, Naegleria fowleri, causes a fatal disease called primary amoebic meningoencephalitis (PAM) in humans and experimental animals. Of the pathogenic mechanism of N. fowleri concerning host tissue invasion, the adherence of amoeba to hose cells is the most important. We previously cloned the nfa1 gene from N. fowleri. The protein displayed immunolocalization in the pseudopodia, especially the food-cups structure, and was related to the contact-dependent mechanism of the amoebic pathogenicity in N. fowleri infection. The cholera toxin B subunit (CTB) and Escherichia coli heat-labile enterotoxin B subunit (LTB) have been used as potent mucosal adjuvants via the parenteral route of immunization in most cases. In this study, to examine the effect of protective immunity of the Nfa1 protein for N. fowleri infection with enhancement by CTB or LTB adjuvants, intranasally immunized BALB/c mice were infected with N. fowleri trophozoites for the development of PAM. The mean time to death of mice immunized with the Nfa1 protein using LTB or CTB adjuvant was prolonged by 5 or 8 days in comparison with that of the control mice. In particular, the survival rate of mice immunized with Nfa1 plus CTB was 100% during the experimental period. The serum IgG levels were significantly increased in mice immunized with Nfa1 protein plus CTB or LTB adjuvants. These results suggest that the Nfa1 protein, with CTB or LTB adjuvants, induces strong protective immunity in mice with PAM due to N. fowleri infection.
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Affiliation(s)
- Jinyoung Lee
- Department of Microbiology, Ajou University School of Medicine, Suwon, 443-721, Republic of Korea
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18
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Zysset-Burri DC, Müller N, Beuret C, Heller M, Schürch N, Gottstein B, Wittwer M. Genome-wide identification of pathogenicity factors of the free-living amoeba Naegleria fowleri. BMC Genomics 2014; 15:496. [PMID: 24950717 PMCID: PMC4082629 DOI: 10.1186/1471-2164-15-496] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 06/11/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The free-living amoeba Naegleria fowleri is the causative agent of the rapidly progressing and typically fatal primary amoebic meningoencephalitis (PAM) in humans. Despite the devastating nature of this disease, which results in > 97% mortality, knowledge of the pathogenic mechanisms of the amoeba is incomplete. This work presents a comparative proteomic approach based on an experimental model in which the pathogenic potential of N. fowleri trophozoites is influenced by the compositions of different media. RESULTS As a scaffold for proteomic analysis, we sequenced the genome and transcriptome of N. fowleri. Since the sequence similarity of the recently published genome of Naegleria gruberi was far lower than the close taxonomic relationship of these species would suggest, a de novo sequencing approach was chosen. After excluding cell regulatory mechanisms originating from different media compositions, we identified 22 proteins with a potential role in the pathogenesis of PAM. Functional annotation of these proteins revealed, that the membrane is the major location where the amoeba exerts its pathogenic potential, possibly involving actin-dependent processes such as intracellular trafficking via vesicles. CONCLUSION This study describes for the first time the 30 Mb-genome and the transcriptome sequence of N. fowleri and provides the basis for the further definition of effective intervention strategies against the rare but highly fatal form of amoebic meningoencephalitis.
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Affiliation(s)
| | | | | | | | | | | | - Matthias Wittwer
- Biology Division, Spiez Laboratory, Federal Office for Civil Protection, Austrasse, CH-3700 Spiez, Switzerland.
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Vaccination with lentiviral vector expressing the nfa1 gene confers a protective immune response to mice infected with Naegleria fowleri. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1055-60. [PMID: 23677321 DOI: 10.1128/cvi.00210-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Naegleria fowleri, a pathogenic free-living amoeba, causes fatal primary amoebic meningoencephalitis (PAM) in humans and animals. The nfa1 gene (360 bp), cloned from a cDNA library of N. fowleri, produces a 13.1-kDa recombinant protein which is located on pseudopodia, particularly the food cup structure. The nfa1 gene plays an important role in the pathogenesis of N. fowleri infection. To examine the effect of nfa1 DNA vaccination against N. fowleri infection, we constructed a lentiviral vector (pCDH) expressing the nfa1 gene. For the in vivo mouse study, BALB/c mice were intranasally vaccinated with viral particles of a viral vector expressing the nfa1 gene. To evaluate the effect of vaccination and immune responses of mice, we analyzed the IgG levels (IgG, IgG1, and IgG2a), cytokine induction (interleukin-4 [IL-4] and gamma interferon [IFN-γ]), and survival rates of mice that developed PAM. The levels of both IgG and IgG subclasses (IgG1 and IgG2a) in vaccinated mice were significantly increased. The cytokine analysis showed that vaccinated mice exhibited greater IL-4 and IFN-γ production than the other control groups, suggesting a Th1/Th2 mixed-type immune response. In vaccinated mice, high levels of Nfa1-specific IgG antibodies continued until 12 weeks postvaccination. The mice vaccinated with viral vector expressing the nfa1 gene also exhibited significantly higher survival rates (90%) after challenge with N. fowleri trophozoites. Finally, the nfa1 vaccination effectively induced protective immunity by humoral and cellular immune responses in N. fowleri-infected mice. These results suggest that DNA vaccination using a viral vector may be a potential tool against N. fowleri infection.
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20
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Kim JH, Lee SH, Sohn HJ, Lee J, Chwae YJ, Park S, Kim K, Shin HJ. The immune response induced by DNA vaccine expressing nfa1 gene against Naegleria fowleri. Parasitol Res 2012; 111:2377-84. [DOI: 10.1007/s00436-012-3093-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 08/21/2012] [Indexed: 11/30/2022]
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21
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LEE YJ, KIM JH, SOHN HJ, LEE J, JUNG SY, CHWAE YJ, KIM K, PARK S, SHIN HJ. Effects of immunization with the rNfa1 protein on experimental Naegleria fowleri-PAM mice. Parasite Immunol 2011; 33:382-9. [DOI: 10.1111/j.1365-3024.2011.01296.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tiewcharoen S, Rabablert J, Chetannachan P, Worawirunwong D, Junnu V, Pungsub N. Activity of chlorpromazine on nfa1 and Mp2CL5 genes of Naegleria fowleri trophozoites. Health (London) 2011. [DOI: 10.4236/health.2011.33032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Sohn HJ, Kim JH, Shin MH, Song KJ, Shin HJ. The Nf-actin gene is an important factor for food-cup formation and cytotoxicity of pathogenic Naegleria fowleri. Parasitol Res 2010; 106:917-24. [PMID: 20143092 DOI: 10.1007/s00436-010-1760-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 01/13/2010] [Indexed: 01/09/2023]
Abstract
Naegleria fowleri destroys target cells by trogocytosis, a phagocytosis mechanism, and a process of piecemeal ingestion of target cells by food-cups. Phagocytosis is an actin-dependent process that involves polymerization of monomeric G-actin into filamentous F-actin. However, despite the numerous studies concerning phagocytosis, its role in the N. fowleri food-cup formation related with trogocytosis has been poorly reported. In this study, we cloned and characterized an Nf-actin gene to elucidate the role of Nf-actin gene in N. fowleri pathogenesis. The Nf-actin gene is composed of 1,128-bp and produced a 54.1-kDa recombinant protein (Nf-actin). The sequence identity was 82% with nonpathogenic Naegleria gruberi but has no sequence identity with other mammals or human actin gene. Anti-Nf-actin polyclonal antibody was produced in BALB/c mice immunized with recombinant Nf-actin. The Nf-actin was localized on the cytoplasm, pseudopodia, and especially, food-cup structure (amoebastome) in N. fowleri trophozoites using immunofluorescence assay. When N. fowleri co-cultured with Chinese hamster ovary cells, Nf-actin was observed to localize around on phagocytic food-cups. We also observed that N. fowleri treated with cytochalasin D as actin polymerization inhibitor or transfected with antisense oligomer of Nf-actin gene had shown the reduced ability of food-cup formation and in vitro cytotoxicity. Finally, it suggests that Nf-actin plays an important role in phagocytic activity of pathogenic N. fowleri.
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Affiliation(s)
- Hae-Jin Sohn
- Department of Microbiology, Ajou University School of Medicine, Suwon, South Korea
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24
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Gianinazzi C, Schild M, Zumkehr B, Wüthrich F, Nüesch I, Ryter R, Schürch N, Gottstein B, Müller N. Screening of Swiss hot spring resorts for potentially pathogenic free-living amoebae. Exp Parasitol 2009; 126:45-53. [PMID: 20036656 DOI: 10.1016/j.exppara.2009.12.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 12/11/2009] [Accepted: 12/17/2009] [Indexed: 11/18/2022]
Abstract
Free-living amoebae (FLA) belonging to Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Sappinia pedata are known to cause infections in humans and animals leading to severe brain pathologies. Worldwide, warm aquatic environments have been found to be suitable habitats for pathogenic FLA. The present study reports on screening for potentially pathogenic FLA in four hot spring resorts in Switzerland. Water samples were taken from water filtration units and from the pools, respectively. Amoebae isolated from samples taken during, or before, the filtration process were demonstrated to be morphologically and phylogenetically related to Stenoamoeba sp., Hartmannella vermiformis, Echinamoeba exundans, and Acanthamoeba healyi. With regard to the swimming pools, FLA were isolated only in one resort, and the isolate was identified as non-pathogenic and as related to E. exundans. Further investigations showed that the isolates morphologically and phylogenetically related to A. healyi displayed a pronounced thermotolerance, and exhibited a marked in vitro cytotoxicity upon 5-day exposure to murine L929 fibroblasts. Experimental intranasal infection of Rag2-immunodeficient mice with these isolates led to severe brain pathologies, and viable trophozoites were isolated from the nasal mucosa, brain tissue, and lungs post mortem. In summary, isolates related to A. healyi were suggestive of being potentially pathogenic to immunocompromised persons. However, the presence of these isolates was limited to the filtration units, and an effective threat for health can therefore be excluded.
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25
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Jung SY, Kim JH, Song KJ, Lee YJ, Kwon MH, Kim K, Park S, Im KI, Shin HJ. Gene silencing of nfa1 affects the in vitro cytotoxicity of Naegleria fowleri in murine macrophages. Mol Biochem Parasitol 2009; 165:87-93. [DOI: 10.1016/j.molbiopara.2009.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 01/12/2009] [Accepted: 01/14/2009] [Indexed: 11/26/2022]
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Kim JH, Kim D, Shin HJ. Contact-independent cell death of human microglial cells due to pathogenic Naegleria fowleri trophozoites. THE KOREAN JOURNAL OF PARASITOLOGY 2008; 46:217-21. [PMID: 19127326 DOI: 10.3347/kjp.2008.46.4.217] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 11/26/2008] [Indexed: 11/23/2022]
Abstract
Free-living Naegleria fowleri leads to a fatal infection known as primary amebic meningoencephalitis in humans. Previously, the target cell death could be induced by phagocytic activity of N. fowleri as a contact-dependent mechanism. However, in this study we investigated the target cell death under a non-contact system using a tissue-culture insert. The human microglial cells, U87MG cells, co-cultured with N. fowleri trophozoites for 30 min in a non-contact system showed morphological changes such as the cell membrane destruction and a reduction in the number. By fluorescence-activated cell sorter (FACS) analysis, U87MG cells co-cultured with N. fowleri trophozoites in a non-contact system showed a significant increase of apoptotic cells (16%) in comparison with that of the control or N. fowleri lysate. When U87MG cells were co-cultured with N. fowleri trophozoites in a non-contact system for 30 min, 2 hr, and 4 hr, the cytotoxicity of amebae against target cells was 40.5, 44.2, and 45.6%, respectively. By contrast, the cytotoxicity of non-pathogenic N. gruberi trophozoites was 10.2, 12.4, and 13.2%, respectively. These results suggest that the molecules released from N. fowleri in a contact-independent manner as well as phagocytosis in a contact-dependent manner may induce the host cell death.
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Affiliation(s)
- Jong-Hyun Kim
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Korea
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27
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Jung SY, Kim JH, Lee YJ, Song KJ, Kim K, Park S, Im KI, Shin HJ. Naegleria fowleri: nfa1 gene knock-down by double-stranded RNAs. Exp Parasitol 2008; 118:208-13. [PMID: 17904122 DOI: 10.1016/j.exppara.2007.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 08/09/2007] [Accepted: 08/09/2007] [Indexed: 10/22/2022]
Abstract
Nfa1 protein expressed by the nfa1 gene that was cloned recently from pathogenic Naegleria fowleri was found in pseudopodia, especially food-cups, and concerned with a mechanism of pathogenicity of N. fowleri. In the present study, N. fowleri nfa1 gene was knocked down using double-stranded RNAs, and the expression of Nfa1 protein was observed. Using synthetic double-stranded RNA of the nfa1 gene in vitro, the nfa1 gene and Nfa1 protein were knocked down about 50.4+/-3.1% and 52+/-2%, respectively. These results suggest that RNA interference (RNAi) may be an effective technique for gene knock-down in N. fowleri trophozoites.
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Affiliation(s)
- Suk-Yul Jung
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea
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28
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Lee YJ, Kim JH, Jeong SR, Song KJ, Kim K, Park S, Park MS, Shin HJ. Production of Nfa1-specific monoclonal antibodies that influences the in vitro cytotoxicity of Naegleria fowleri trophozoites on microglial cells. Parasitol Res 2007; 101:1191-6. [PMID: 17610083 DOI: 10.1007/s00436-007-0600-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 05/24/2007] [Indexed: 11/29/2022]
Abstract
Naegleria fowleri, agent of fatal primary amoebic meningoencephalitis, appears to induce cytotoxicity mechanically through its contact with the cell. The nfa1 gene cloned from a cDNA library of pathogenic N. fowleri by immunoscreening consists of 360 bp and expresses a 13.1-kDa recombinant protein (rNfa1) that demonstrated localization in the pseudopodia when examined using immunocytochemistry. To study the mechanisms involved in N. fowleri cytotoxicity, we developed a large volume of rNfa1-specific monoclonal antibody (McAb) against a 17-kDa His-tag fusion rNfa1 protein using a cell fusion technique. We established eight McAb-producing hybridoma cells. The antibodies were all immunoglobulin G2b and reacted strongly with a 17-kDa band representing the rNfa1 fusion protein in Western blotting, demonstrating immunoreactivity to the Nfa1 protein in pseudopodia (especially in the food cups) of N. fowleri trophozoites. A 51Cr-release assay indicated N. fowleri cytotoxicity by demonstrating that it eliminated 37.8, 60.6, and 98.8% of the target (microglial) cells 6, 12, and 24 h after co-incubation, respectively. When an anti-Nfa1 McAb was added to the coculture system, N. fowleri cytotoxicity decreased to 29.8, 44.1, and 66.3%, respectively.
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Affiliation(s)
- Yang-Jin Lee
- Department of Microbiology, Molecular Science & Technology, Ajou University School of Medicine, Suwon, 443-721, South Korea
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Song KJ, Jeong SR, Park S, Kim K, Kwon MH, Im KI, Pak JH, Shin HJ. Naegleria fowleri: Functional expression of the Nfa1 protein in transfected Naegleria gruberi by promoter modification. Exp Parasitol 2006; 112:115-20. [PMID: 16321386 DOI: 10.1016/j.exppara.2005.10.004] [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: 03/29/2005] [Revised: 10/05/2005] [Accepted: 10/07/2005] [Indexed: 10/25/2022]
Abstract
To establish a transient transfection system in a Naegleria, we constructed three nfa1-pEGFP-N1 vectors by the promoter replacement and insertion of a nfa1 gene and transfected the DNAs into Naegleria gruberi using a lipid reagent. The transfection efficiency and usefulness of the three modified vectors were estimated by identifying the expressions of the EGFP and Nfa1 protein from N. gruberi. After transfection, the Nfa1 protein was functionally expressed on pseudopodia of N. gruberi. The strong GFP fluorescence was observed in N. gruberi transfected with the actin-nfa1-pEGFP-N1 vector, of which the CMV promoter region in the expression vector was replaced with the actin 5' UTR region. Additionally, when transgenic N. gruberi trophozoites were co-cultured with CHO target cells, the Nfa1 protein was also located on cytoplasm and pseudopodia, especially on a food cup that was formed in contact with target cells as it shown in pathogenic N. fowleri.
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Affiliation(s)
- Kyoung-Ju Song
- Department of Microbiology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea
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Oh YH, Jeong SR, Kim JH, Song KJ, Kim K, Park S, Sohn S, Shin HJ. Cytopathic changes and pro-inflammatory cytokines induced by Naegleria fowleri trophozoites in rat microglial cells and protective effects of an anti-Nfa1 antibody. Parasite Immunol 2006; 27:453-9. [PMID: 16255744 DOI: 10.1111/j.1365-3024.2005.00799.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Naegleria fowleri, a free-living amoeba, causes fatal primary amoebic meningoencephalitis in experimental animals and humans. The nfa1 gene (360 bp) was previously cloned from a cDNA library of pathogenic N. fowleri by immunoscreening, and produced a 13.1-kDa recombinant protein that showed pseudopodia-specific localization by immunocytochemistry. On the basis of an idea that the pseudopodia-specific Nfa1 protein seems to be involved in the pathogenicity of N. fowleri, the cytopathic activity of N. fowleri trophozoites co-cultured with rat microglial cells was observed, and the effects of an anti-Nfa1 antibody in a co-culture system were elucidated. Using light, scanning and transmission electron microscopy, it was seen that N. fowleri trophozoites in contact with microglial cells produced vigorous pseudopodia and a food-cup structure. Microglial cells were destroyed by N. fowleri trophozoites as seen from necrotic cell death in a time-dependent manner. In a(51)Cr release assay, N. fowleri showed 17.8%, 24.9%, 54.6% and 98% cytotoxicity against microglial cells at 3, 6, 12 and 24 h post-incubation, respectively. However, when anti-Nfa1 antibody was added in a coculture system, N. fowleri cytotoxicity was reduced to 15.5%, 20.3%, 46.7% and 66.9%, respectively. Moreover, microglial cells co-cultured with N. fowleri trophozoites secreted the pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-6. In the presence of anti-Nfa1 antibody, the secretion of TNF-alpha was slightly, but not significantly, decreased.
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Affiliation(s)
- Y-H Oh
- Department of Microbiology, Institute for Medical Science, Ajou University School of Medicine, Suwon, Korea
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