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Retana Moreira L, Cornet-Gomez A, Sepulveda MR, Molina-Castro S, Alvarado-Ocampo J, Chaves Monge F, Jara Rojas M, Osuna A, Abrahams Sandí E. Providing an in vitro depiction of microglial cells challenged with immunostimulatory extracellular vesicles of Naegleria fowleri. Front Microbiol 2024; 15:1346021. [PMID: 38374922 PMCID: PMC10876093 DOI: 10.3389/fmicb.2024.1346021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/16/2024] [Indexed: 02/21/2024] Open
Abstract
Naegleria fowleri is the causative agent of primary amoebic meningoencephalitis, a rapid and acute infection of the central nervous system with a fatal outcome in >97% of cases. Due to the infrequent report of cases and diagnostic gaps that hinder the possibility of recovering clinic isolates, studies related to pathogenesis of the disease are scarce. However, the secretion of cytolytic molecules has been proposed as a factor involved in the progression of the infection. Several of these molecules could be included in extracellular vesicles (EVs), making them potential virulence factors and even modulators of the immune response in this infection. In this work, we evaluated the immunomodulatory effect of EVs secreted by two clinic isolates of Naegleria fowleri using in vitro models. For this purpose, characterization analyses between EVs produced by both isolates were first performed, for subsequent gene transcription analyses post incubation of these vesicles with primary cultures from mouse cell microglia and BV-2 cells. Analyses of morphological changes induced in primary culture microglia cells by the vesicles were also included, as well as the determination of the presence of nucleic acids of N. fowleri in the EV fractions. Results revealed increased expression of NOS, proinflammatory cytokines IL-6, TNF-α, and IL-23, and the regulatory cytokine IL-10 in primary cultures of microglia, as well as increased expression of NOS and IL-13 in BV-2 cells. Morphologic changes from homeostatic microglia, with small cellular body and long processes to a more amoeboid morphology were also observed after the incubation of these cells with EVs. Regarding the presence of nucleic acids, specific Naegleria fowleri DNA that could be amplified using both conventional and qPCR was confirmed in the EV fractions. Altogether, these results confirm the immunomodulatory effects of EVs of Naegleria fowleri over microglial cells and suggest a potential role of these vesicles as biomarkers of primary acute meningoencephalitis.
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Affiliation(s)
- Lissette Retana Moreira
- Departamento de Parasitología, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Alberto Cornet-Gomez
- Grupo de Bioquímica y Parasitología Molecular (CTS 183), Departamento de Parasitología, Campus de Fuentenueva, Instituto de Biotecnología, Universidad de Granada, Granada, Spain
| | - M. Rosario Sepulveda
- Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Silvia Molina-Castro
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, Costa Rica
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
| | - Johan Alvarado-Ocampo
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Frida Chaves Monge
- Departamento de Parasitología, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Mariana Jara Rojas
- Departamento de Parasitología, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Antonio Osuna
- Grupo de Bioquímica y Parasitología Molecular (CTS 183), Departamento de Parasitología, Campus de Fuentenueva, Instituto de Biotecnología, Universidad de Granada, Granada, Spain
| | - Elizabeth Abrahams Sandí
- Departamento de Parasitología, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
- Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
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Akbar N, Siddiqui R, El-Gamal MI, Zaraei SO, Alawfi BS, Khan NA. The anti-amoebic potential of carboxamide derivatives containing sulfonyl or sulfamoyl moieties against brain-eating Naegleria fowleri. Parasitol Res 2023; 122:2539-2548. [PMID: 37665414 DOI: 10.1007/s00436-023-07953-w] [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: 05/22/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023]
Abstract
Naegleria fowleri is a free-living thermophilic flagellate amoeba that causes a rare but life-threatening infection called primary amoebic meningoencephalitis (PAM), with a very high fatality rate. Herein, the anti-amoebic potential of carboxamide derivatives possessing sulfonyl or sulfamoyl moiety was assessed against pathogenic N. fowleri using amoebicidal, cytotoxicity and cytopathogenicity assays. The results from amoebicidal experiments showed that derivatives dramatically reduced N. fowleri viability. Selected derivatives demonstrated IC50 values at lower concentrations; 1j showed IC50 at 24.65 μM, while 1k inhibited 50% amoebae growth at 23.31 μM. Compounds with significant amoebicidal effects demonstrated limited cytotoxicity against human cerebral microvascular endothelial cells. Finally, some derivatives mitigated N. fowleri-instigated host cell death. Ultimately, this study demonstrated that 1j and 1k exhibited potent anti-amoebic activity and ought to be looked at in future studies for the development of therapeutic anti-amoebic pharmaceuticals. Further investigation is required to determine the clinical relevance of our findings.
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Affiliation(s)
- Noor Akbar
- Research Institute of Medical and Health Sciences, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates
| | - Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah, 26666, United Arab Emirates
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey
| | - Mohammed I El-Gamal
- Research Institute of Medical and Health Sciences, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates.
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah, Sharjah, 27272, United Arab Emirates.
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt.
| | - Seyed-Omar Zaraei
- Research Institute of Medical and Health Sciences, University of Sharjah, University City, Sharjah, 27272, United Arab Emirates
| | - Bader S Alawfi
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Taibah University, Madinah, 42353, Saudi Arabia
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
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Sharma M, Lozano-Amado D, Chowdhury D, Singh U. Extracellular Vesicles and Their Impact on the Biology of Protozoan Parasites. Trop Med Infect Dis 2023; 8:448. [PMID: 37755909 PMCID: PMC10537256 DOI: 10.3390/tropicalmed8090448] [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: 08/07/2023] [Revised: 09/11/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023] Open
Abstract
Extracellular vesicles (EVs) are lipid-membrane-bound structures produced naturally by all cells and have a variety of functions. EVs act as vehicles for transporting important molecular signals from one cell to another. Several parasites have been shown to secrete EVs, and their biological functions have been extensively studied. EVs have been shown to facilitate communication with the host cells (such as modulation of the host's immune system or promoting attachment and invasion into the host cells) or for communication between parasitic cells (e.g., transferring drug-resistance genes or factors modulating stage conversion). It is clear that EVs play an important role in host-parasite interactions. In this review, we summarized the latest research on the EVs secreted by protozoan parasites and their role in host-parasite and parasite-parasite communications.
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Affiliation(s)
- Manu Sharma
- Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA 94305, USA; (M.S.); (D.L.-A.); (D.C.)
| | - Daniela Lozano-Amado
- Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA 94305, USA; (M.S.); (D.L.-A.); (D.C.)
| | - Debabrata Chowdhury
- Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA 94305, USA; (M.S.); (D.L.-A.); (D.C.)
| | - Upinder Singh
- Division of Infectious Diseases, School of Medicine, Stanford University, Stanford, CA 94305, USA; (M.S.); (D.L.-A.); (D.C.)
- Department of Microbiology and Immunology, School of Medicine, Stanford University, Stanford, CA 94305, USA
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Lê HG, Kang JM, Võ TC, Yoo WG, Na BK. Naegleria fowleri Extracellular Vesicles Induce Proinflammatory Immune Responses in BV-2 Microglial Cells. Int J Mol Sci 2023; 24:13623. [PMID: 37686429 PMCID: PMC10487526 DOI: 10.3390/ijms241713623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/26/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
Extracellular vesicles (EVs) of protozoan parasites have diverse biological functions that are essential for parasite survival and host-parasite interactions. In this study, we characterized the functional properties of EVs from Naegleria fowleri, a pathogenic amoeba that causes a fatal brain infection called primary amoebic meningoencephalitis (PAM). N. fowleri EVs (NfEVs) have been shown to be internalized by host cells such as C6 glial cells and BV-2 microglial cells without causing direct cell death, indicating their potential roles in modulating host cell functions. NfEVs induced increased expression of proinflammatory cytokines and chemokines such as TNF-α, IL-1α, IL-1β, IL-6, IL-17, IFN-γ, MIP-1α, and MIP-2 in BV-2 microglial cells; these increases were initiated via MyD88-dependent TLR-2/TLR-4. The production levels of proinflammatory cytokines and chemokines in NfEVs-stimulated BV-2 microglial cells were effectively downregulated by inhibitors of MAPK, NF-κB, or JAK-STAT. Phosphorylation levels of JNK, p38, ERK, p65, JAK-1, and STAT3 were increased in NfEVs-stimulated BV-2 microglial cells but were effectively suppressed by each corresponding inhibitor. These results suggest that NfEVs could induce proinflammatory immune responses in BV-2 microglial cells via the NF-κB-dependent MAPK and JAK-STAT signaling pathways. Taken together, these findings suggest that NfEVs are pathogenic factors involved in the contact-independent pathogenic mechanisms of N. fowleri by inducing proinflammatory immune responses in BV-2 microglial cells, further contributing to deleterious inflammation in infected foci by activating subsequent inflammation cascades in other brain cells.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine, Institute of Medical Science, College of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea (J.-M.K.); (T.C.V.); (W.G.Y.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, Institute of Medical Science, College of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea (J.-M.K.); (T.C.V.); (W.G.Y.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, Institute of Medical Science, College of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea (J.-M.K.); (T.C.V.); (W.G.Y.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Won Gi Yoo
- Department of Parasitology and Tropical Medicine, Institute of Medical Science, College of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea (J.-M.K.); (T.C.V.); (W.G.Y.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, Institute of Medical Science, College of Medicine, Gyeongsang National University, Jinju 52727, Republic of Korea (J.-M.K.); (T.C.V.); (W.G.Y.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Republic of Korea
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Chen CW, Moseman EA. Pro-inflammatory cytokine responses to Naegleria fowleri infection. FRONTIERS IN TROPICAL DISEASES 2023; 3. [PMID: 37065537 PMCID: PMC10104475 DOI: 10.3389/fitd.2022.1082334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Naegleria fowleri, or the “brain-eating amoeba,” is responsible for a rare, but lethal, infection known as primary amoebic meningoencephalitis (PAM). Confirmed PAM cases have seen both a rise in numbers, as well as expansion of geographic range over the past several decades. There is no effective therapy for PAM and the clinical prognosis remains grim with a mortality rate over 95%. The role of the immune response in disease prevention and disease severity remains unclear. In this review, we explore potential roles of inflammatory immune responses to N. fowleri in disease pathogenesis with a primary focus on pro-inflammatory cytokines IL-1, IL-6, and TNFα. We also discuss modulating proinflammatory cytokines as an additional immune therapy in PAM treatment.
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Lê HG, Kang JM, Võ TC, Na BK. Naegleria fowleri Cathepsin B Induces a Pro-Inflammatory Immune Response in BV-2 Microglial Cells via NF-κB and AP-1 Dependent-MAPK Signaling Pathway. Int J Mol Sci 2022; 23:ijms23158388. [PMID: 35955520 PMCID: PMC9369353 DOI: 10.3390/ijms23158388] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/20/2022] [Accepted: 07/27/2022] [Indexed: 11/30/2022] Open
Abstract
Naegleria fowleri is a ubiquitous protozoa parasite that can cause primary amoebic meningoencephalitis (PAM), a fatal brain infection in humans. Cathepsin Bs of N. fowleri (NfCBs) are multifamily enzymes. Although their pathogenic mechanism in PAM is not clearly understood yet, NfCBs have been proposed as pathogenic factors involved in the pathogenicity of amoeba. In this study, the immune response of BV-2 microglial cells induced by NfCB was analyzed. Recombinant NfCB (rNfCB) evoked enhanced expressions of TLR-2, TLR-4, and MyD88 in BV-2 microglial cells. This enzyme also induced an elevated production of several pro-inflammatory cytokines such as TNF-α, IL-1α, IL-1β, and IL-6 and iNOS in cells. The inhibition of mitogen-activated protein kinases (MAPKs), including JNK, p38, and ERK, effectively reduced the production of these pro-inflammatory cytokines. The rNfCB-induced production of pro-inflammatory cytokines in BV-2 microglial cells was suppressed by inhibiting NF-kB and AP-1. Phosphorylation and nuclear translocation of p65 in cells were also enhanced by rNfCB. These results suggest that NfCB can induce a pro-inflammatory immune response in BV-2 microglial cells via the NF-κB- and AP-1-dependent MAPK signaling pathways. Such a NfCB-induced pro-inflammatory immune response in BV-2 microglial cells might contribute to the pathogenesis of PAM caused by amoeba, by exacerbating deleterious immune responses and tissue damages in N. fowleri-infected foci of the brain.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea; (H.G.L.); (J.-M.K.); (T.C.V.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea; (H.G.L.); (J.-M.K.); (T.C.V.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea; (H.G.L.); (J.-M.K.); (T.C.V.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea; (H.G.L.); (J.-M.K.); (T.C.V.)
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
- Correspondence:
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7
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Extracellular Vesicles from Naegleria fowleri Induce IL-8 Response in THP-1 Macrophage. Pathogens 2022; 11:pathogens11060632. [PMID: 35745486 PMCID: PMC9231210 DOI: 10.3390/pathogens11060632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/26/2022] [Accepted: 05/28/2022] [Indexed: 11/17/2022] Open
Abstract
Extracellular vesicles (EVs) released from pathogenic protozoans play crucial roles in host–parasite communication and disease pathogenesis. Naegleria fowleri is a free-living protozoan causing primary amoebic meningoencephalitis, a fatal disease in the central nervous system. This study aims to explore the roles of N. fowleri-derived EVs (Nf-EVs) in host–pathogen interactions using the THP-1 cell line as a model. The Nf-EVs were isolated from the N. fowleri trophozoite culture supernatant using sequential centrifugation and characterized by nanoparticle tracking analysis and transmission electron microscopy. The functional roles of Nf-EVs in the apoptosis and immune response induction of THP-1 monocytes and macrophages were examined by flow cytometry, quantitative PCR, and ELISA. Results showed that Nf-EVs displayed vesicles with bilayer membrane structure approximately 130–170 nm in diameter. The Nf-EVs can be internalized by macrophages and induce macrophage responses by induction of the expression of costimulatory molecules CD80, CD86, HLA-DR, and CD169 and the production of cytokine IL-8. However, Nf-EVs did not affect the apoptosis of macrophages. These findings illustrate the potential role of Nf-EVs in mediating the host immune cell activation and disease pathogenesis.
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Guzmán-Téllez P, Martínez-Castillo M, Flores-Huerta N, Rosales-Morgan G, Pacheco-Yépez J, la Garza MD, Serrano-Luna J, Shibayama M. Lectins as virulence factors in Entamoeba histolytica and free-living amoebae. Future Microbiol 2020; 15:919-936. [PMID: 32716210 DOI: 10.2217/fmb-2019-0275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Currently, there is growing interest in the identification and purification of microbial lectins due to their involvement in the pathogenicity mechanisms of pathogens, such as Entamoeba histolytica and free-living amoebae. The Gal/GalNAc lectin from E. histolytica participates in adhesion, cytotoxicity and regulation of immune responses. Furthermore, mannose- and galactose-binding protein have been described in Acanthamoeba castellanii and Balamuthia mandrillaris, respectively and they also contribute to host damage. Finally, in Naegleria fowleri, molecules containing mannose and fucose are implicated in adhesion and cytotoxicity. Considering their relevance in the pathogenesis of the diseases caused by these protozoa, lectins appear to be promising targets in the diagnosis, vaccination and treatment of these infections.
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Affiliation(s)
- Paula Guzmán-Téllez
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Moisés Martínez-Castillo
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
- Department of Experimental Medicine, Liver, Pancreas & Motility Laboratory (HIPAM), School of Medicine, National Autonomous University of Mexico (UNAM) Mexico City, Mexico
| | - Nadia Flores-Huerta
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Gabriela Rosales-Morgan
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Judith Pacheco-Yépez
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Mireya de la Garza
- Department of Cell Biology, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Jesús Serrano-Luna
- Department of Cell Biology, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, Mexico
| | - Mineko Shibayama
- Department of Infectomics & Molecular Pathogenesis, Center for Research & Advanced Studies of The National Polytechnic Institute, Av. IPN 2508, Mexico City 07360, 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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10
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Figarella K, Wolburg H, Garaschuk O, Duszenko M. Microglia in neuropathology caused by protozoan parasites. Biol Rev Camb Philos Soc 2019; 95:333-349. [PMID: 31682077 DOI: 10.1111/brv.12566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 12/31/2022]
Abstract
Involvement of the central nervous system (CNS) is the most severe consequence of some parasitic infections. Protozoal infections comprise a group of diseases that together affect billions of people worldwide and, according to the World Health Organization, are responsible for more than 500000 deaths annually. They include African and American trypanosomiasis, leishmaniasis, malaria, toxoplasmosis, and amoebiasis. Mechanisms underlying invasion of the brain parenchyma by protozoa are not well understood and may depend on parasite nature: a vascular invasion route is most common. Immunosuppression favors parasite invasion into the CNS and therefore the host immune response plays a pivotal role in the development of a neuropathology in these infectious diseases. In the brain, microglia are the resident immune cells active in defense against pathogens that target the CNS. Beside their direct role in innate immunity, they also play a principal role in coordinating the trafficking and recruitment of other immune cells from the periphery to the CNS. Despite their evident involvement in the neuropathology of protozoan infections, little attention has given to microglia-parasite interactions. This review describes the most prominent features of microglial cells and protozoan parasites and summarizes the most recent information regarding the reaction of microglial cells to parasitic infections. We highlight the involvement of the periphery-brain axis and emphasize possible scenarios for microglia-parasite interactions.
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Affiliation(s)
- Katherine Figarella
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Michael Duszenko
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
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11
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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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12
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Martínez-Castillo M, Santos-Argumedo L, Galván-Moroyoqui JM, Serrano-Luna J, Shibayama M. Toll-like receptors participate in Naegleria fowleri recognition. Parasitol Res 2017; 117:75-87. [PMID: 29128927 DOI: 10.1007/s00436-017-5666-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/25/2017] [Indexed: 02/06/2023]
Abstract
Naegleria fowleri is a protozoan that invades the central nervous system and causes primary amoebic meningoencephalitis. It has been reported that N. fowleri induces an important inflammatory response during the infection. In the present study, we evaluated the roles of Toll-like receptors in the recognition of N. fowleri trophozoites by human mucoepithelial cells, analyzing the expression and production of innate immune response mediators. After amoebic interactions with NCI-H292 cells, the expression and production levels of IL-8, TNF-α, IL-1β, and human beta defensin-2 were evaluated by RT-PCR, ELISA, immunofluorescence, and dot blot assays, respectively. To determine whether the canonical signaling pathways were engaged, we used different inhibitors, namely, IMG-2005 for MyD88 and BAY 11-7085 for the nuclear factor NFkB. Our results showed that the expression and production of the pro-inflammatory cytokines and beta defensin-2 were induced by N. fowleri mainly through the canonical TLR4 pathway in a time-dependent manner.
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Affiliation(s)
- Moisés Martínez-Castillo
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Av. IPN 2508, 07360, Mexico City, Mexico
| | - Leopoldo Santos-Argumedo
- Department of Molecular Biomedicine, Center for Research and Advanced Studies of the National Polytechnic Institute, Av. IPN 2508, 07360, Mexico City, Mexico
| | - José Manuel Galván-Moroyoqui
- Department of Medicine and Health Sciences, University of Sonora, Boulevard Luis Donaldo Colosio and Francisco Q. Salazar S/N, 83000, Hermosillo, SON, Mexico
| | - Jesús Serrano-Luna
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute, Av. IPN 2508, 07360, Mexico City, Mexico
| | - Mineko Shibayama
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Av. IPN 2508, 07360, Mexico City, Mexico.
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13
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Lee J, Kang JM, Kim TI, Kim JH, Sohn HJ, Na BK, Shin HJ. Excretory and Secretory Proteins of Naegleria fowleri Induce Inflammatory Responses in BV-2 Microglial Cells. J Eukaryot Microbiol 2016; 64:183-192. [PMID: 27480446 DOI: 10.1111/jeu.12350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/24/2016] [Accepted: 07/26/2016] [Indexed: 01/01/2023]
Abstract
Naegleria fowleri, a free-living amoeba that is found in diverse environmental habitats, can cause a type of fulminating hemorrhagic meningoencephalitis, primary amoebic meningoencephalitis (PAM), in humans. The pathogenesis of PAM is not fully understood, but it is likely to be primarily caused by disruption of the host's nervous system via a direct phagocytic mechanism by the amoeba. Naegleria fowleri trophozoites are known to secrete diverse proteins that may indirectly contribute to the pathogenic function of the amoeba, but this factor is not clearly understood. In this study, we analyzed the inflammatory responses in BV-2 microglial cells induced by excretory and secretory proteins of N. fowleri (NfESP). Treatment of BV-2 cells with NfESP induced the expression of various cytokines and chemokines, including the proinflammatory cytokines IL-1α and TNF-α. NfESP-induced IL-1α and TNF-α expression in BV-2 cells were regulated by p38, JNK, and ERK MAPKs. NfESP-induced IL-1α and TNF-α production in BV-2 cells were effectively downregulated by inhibition of NF-kB and AP-1. These results collectively suggest that NfESP stimulates BV-2 cells to release IL-1α and TNF-α via NF-kB- and AP-1-dependent MAPK signaling pathways. The released cytokines may contribute to inflammatory responses in microglia and other cell types in the brain during N. fowleri infection.
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Affiliation(s)
- Jinyoung Lee
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, 52727, Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, 52727, Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Tae Im Kim
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, 52727, Korea
| | - Jong-Hyun Kim
- Department of Parasitology, College of Veterinary Medicine, Gyeongsang National University, Jinju, 52828, Korea
| | - Hae-Jin Sohn
- Department of Microbiology, Ajou University School of Medicine, Suwon, 16499, Korea.,Department of Biomedical Science, Ajou University School of Medicine, Suwon, 16499, Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, 52727, Korea.,BK21Plus Team for Anti-aging Biotechnology and Industry, Department of Convergence Medical Science, Gyeongsang National University, Jinju, 52727, Korea
| | - Ho-Joon Shin
- Department of Microbiology, Ajou University School of Medicine, Suwon, 16499, Korea.,Department of Biomedical Science, Ajou University School of Medicine, Suwon, 16499, Korea
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14
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NLRP3 Inflammasome Activation in THP-1 Target Cells Triggered by Pathogenic Naegleria fowleri. Infect Immun 2016; 84:2422-8. [PMID: 27297387 DOI: 10.1128/iai.00275-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/06/2016] [Indexed: 01/06/2023] Open
Abstract
Naegleria fowleri, known as the brain-eating amoeba, causes acute primary amoebic meningoencephalitis. During swimming and other recreational water activities, N. fowleri trophozoites penetrate the nasal mucosa and invade the olfactory bulbs, resulting in intense inflammatory reactions in the forebrain tissue. To investigate what kinds of inflammasome molecules are expressed in target cells due to N. fowleri infection, human macrophage cells (THP-1 cells) were cocultured with N. fowleri trophozoites in a noncontact system, and consequently, interleukin-1β (IL-1β) production was estimated. Caspase-1 activation and IL-1β production from THP-1 cells by Western blotting and the culture supernatant by enzyme-linked immunosorbent assay analysis were observed at 3 h after cocultivation. In addition, the increased expression of ASC and NLRP3, which make up an inflammasome complex, was also observed at 3 h after cocultivation. To confirm the caspase-1 activation and IL-1β production via the NLRP3 inflammasome in THP-1 cells triggered by N. fowleri trophozoites, THP-1 cells were pretreated with several inhibitors. The inhibition assay showed that CA-074 (a cathepsin B inhibitor), glybenclamide (an NLRP3 molecule inhibitor), and N-benzyloxycarbony-Val-Ala-Asp(O-methyl)-fluoromethylketone (Z-VAD-FMK; a caspase-1 inhibitor) reduced the levels of caspase-1 activation and IL-1β production from THP-1 cells. This study suggests that N. fowleri infection induces the NLRP3 inflammasome, which activates caspase-1 and subsequently produces IL-1β, thus resulting in inflammation.
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15
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Cholera Toxin Subunit B as Adjuvant--An Accelerator in Protective Immunity and a Break in Autoimmunity. Vaccines (Basel) 2015; 3:579-96. [PMID: 26350596 PMCID: PMC4586468 DOI: 10.3390/vaccines3030579] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/07/2015] [Accepted: 07/20/2015] [Indexed: 11/16/2022] Open
Abstract
Cholera toxin subunit B (CTB) is the nontoxic portion of cholera toxin. Its affinity to the monosialotetrahexosylganglioside (GM1) that is broadly distributed in a variety of cell types including epithelial cells of the gut and antigen presenting cells, macrophages, dendritic cells, and B cells, allows its optimal access to the immune system. CTB can easily be expressed on its own in a variety of organisms, and several approaches can be used to couple it to antigens, either by genetic fusion or by chemical manipulation, leading to strongly enhanced immune responses to the antigens. In autoimmune diseases, CTB has the capacity to evoke regulatory responses and to thereby dampen autoimmune responses, in several but not all animal models. It remains to be seen whether the latter approach translates to success in the clinic, however, the versatility of CTB to manipulate immune responses in either direction makes this protein a promising adjuvant for vaccine development.
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16
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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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17
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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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18
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Lee J, Kim JH, Sohn HJ, Yang HJ, Na BK, Chwae YJ, Park S, Kim K, Shin HJ. Novel cathepsin B and cathepsin B-like cysteine protease of Naegleria fowleri excretory-secretory proteins and their biochemical properties. Parasitol Res 2014; 113:2765-76. [PMID: 24832815 DOI: 10.1007/s00436-014-3936-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 04/30/2014] [Indexed: 12/29/2022]
Abstract
Naegleria fowleri causes a lethal primary amoebic meningoencephalitis (PAM) in humans and experimental animals, which leads to death within 7-14 days. Cysteine proteases of parasites play key roles in nutrient uptake, excystment/encystment, host tissue invasion, and immune evasion. In this study, we cloned N. fowleri cathepsin B (nfcpb) and cathepsin B-like (nfcpb-L) genes from our cDNA library of N. fowleri. The full-length sequences of genes were 1,038 and 939 bp (encoded 345 and 313 amino acids), and molecular weights were 38.4 and 34 kDa, respectively. Also, nfcpb and nfcpb-L showed a 56 and 46 % identity to Naegleria gruberi cathepsin B and cathepsin B-like enzyme, respectively. Recombinant NfCPB (rNfCPB) and NfCPB-L (rNfCPB-L) proteins were expressed by the pEX5-NT/TOPO vector that was transformed into Escherichia coli BL21, and they showed 38.4 and 34 kDa bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis using their respective antibodies. Proteolytic activity of refolded rNfCPB and rNfCPB-L was maximum at a pH of 4.5, and the most effective substrate was Z-LR-MCA. rNfCPB and rNfCPB-L showed proteolytic activity for several proteins such as IgA, IgG, IgM, collagen, fibronectin, hemoglobin, and albumin. These results suggested that NfCPB and NfCPB-L cysteine protease are important components of the N. fowleri ESP, and they may play important roles in host tissue invasion and immune evasion as pathogens that cause N. fowleri PAM.
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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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19
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Kim JH, Song AR, Sohn HJ, Lee J, Yoo JK, Kwon D, Shin HJ. IL-1β and IL-6 activate inflammatory responses of astrocytes againstNaegleria fowleriinfection via the modulation of MAPKs and AP-1. Parasite Immunol 2013. [DOI: 10.1111/pim.12021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- J.-H. Kim
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
| | - A.-R. Song
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
| | - H.-J. Sohn
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
| | - J. Lee
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
| | - J.-K. Yoo
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
| | - D. Kwon
- Department of Microbiology; School of Medicine; Kwandong University; Gangneung Republic of Korea
| | - H.-J. Shin
- Department of Microbiology; Department of Molecular Science and Technology; Ajou University School of Medicine; Suwon Republic of Korea
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20
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Kim JH, Sohn HJ, Lee SH, Kwon D, Shin HJ. Induction of interleukin-8 by Naegleria fowleri lysates requires activation of extracellular signal-regulated kinase in human astroglial cells. Parasitol Res 2012; 111:587-92. [PMID: 22411631 PMCID: PMC7088079 DOI: 10.1007/s00436-012-2872-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 02/21/2012] [Indexed: 10/28/2022]
Abstract
Naegleria fowleri is a pathogenic free-living amoeba which causes primary amoebic meningoencephalitis in humans and experimental animals. To investigate the mechanisms of such inflammatory diseases, potential chemokine gene activation in human astroglial cells was investigated following treatment with N. fowleri lysates. We demonstrated that N. fowleri are potent inducers for the expression of interleukin-8 (IL-8) genes in human astroglial cells which was preceded by activation of extracellular signal-regulated kinase (ERK). In addition, N. fowleri lysates induces the DNA binding activity of activator protein-1 (AP-1), an important transcription factor for IL-8 induction. The specific mitogen-activated protein kinase kinase/ERK inhibitor, U0126, blocks N. fowleri-mediated AP-1 activation and subsequent IL-8 induction. N. fowleri-induced IL-8 expression requires activation of ERK in human astroglial cells. These findings indicate that treatment of N. fowleri on human astroglial cells leads to the activation of AP-1 and subsequent expression of IL-8 which are dependent on ERK activation. These results may help understand the N. fowleri-mediated upregulation of chemokine and cytokine expression in the astroglial cells.
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Affiliation(s)
- Jong-Hyun Kim
- Department of Microbiology, and Molecular Science & Technology, Ajou University School of Medicine, Suwon 443-721, Republic of Korea
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21
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Lee YJ, Park CE, Kim JH, Sohn HJ, Lee J, Jung SY, Shin HJ. Naegleria fowleri lysate induces strong cytopathic effects and pro-inflammatory cytokine release in rat microglial cells. THE KOREAN JOURNAL OF PARASITOLOGY 2011; 49:285-90. [PMID: 22072830 PMCID: PMC3210847 DOI: 10.3347/kjp.2011.49.3.285] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 06/28/2011] [Accepted: 06/29/2011] [Indexed: 11/23/2022]
Abstract
Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A 51Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-α, IL-6, and IL-1β, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.
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Affiliation(s)
- Yang-Jin Lee
- Department of Microbiology, and Department of Molecular Science and Technology, Ajou University School of Medicine, Suwon 443-721, Korea
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22
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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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23
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Cervantes-Sandoval I, Jesús Serrano-Luna J, Pacheco-Yépez J, Silva-Olivares A, Tsutsumi V, Shibayama M. Differences between Naegleria fowleri and Naegleria gruberi in expression of mannose and fucose glycoconjugates. Parasitol Res 2010; 106:695-701. [DOI: 10.1007/s00436-010-1727-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 01/04/2010] [Indexed: 11/28/2022]
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24
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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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25
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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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26
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Tiewcharoen S, Rabablert J, Chetanachan P, Junnu V, Worawirounwong D, Malainual N. Scanning electron microscopic study of human neuroblastoma cells affected with Naegleria fowleri Thai strains. Parasitol Res 2008; 103:1119-23. [DOI: 10.1007/s00436-008-1103-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 06/13/2008] [Indexed: 11/28/2022]
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Cervantes-Sandoval I, Serrano-Luna JDJ, García-Latorre E, Tsutsumi V, Shibayama M. Characterization of brain inflammation during primary amoebic meningoencephalitis. Parasitol Int 2008; 57:307-13. [PMID: 18374627 DOI: 10.1016/j.parint.2008.01.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 01/21/2008] [Accepted: 01/26/2008] [Indexed: 01/21/2023]
Abstract
Naegleria fowleri is a free-living amoeba and the etiologic agent of primary amoebic meningoencephalitis (PAM). Trophozoites reach the brain by penetrating the olfactory epithelium, and invasion of the olfactory bulbs results in an intense inflammatory reaction. The contribution of the inflammatory response to brain damage in experimental PAM has not been delineated. Using both optical and electron microscopy, we analyzed the morphologic changes in the brain parenchyma due to inflammation during experimental PAM. Several N. fowleri trophozoites were observed in the olfactory bulbs 72 h post-inoculation, and the number of amoebae increased rapidly over the next 24 h. Eosinophils and neutrophils surrounding the amoebae were then noted at later times during infection. Electron microscopic examination of the increased numbers of neutrophils and the interactions with trophozoites indicated an active attempt to eliminate the amoebae. The extent of inflammation increased over time, with a predominant neutrophil response indicating important signs of damage and necrosis of the parenchyma. These data suggest a probable role of inflammation in tissue damage. To test the former hypothesis, we used CD38-/- knockout mice with deficiencies in chemotaxis to compare the rate of mortality with the parental strain, C57BL/6J. The results showed that inflammation and mortality were delayed in the knockout mice. Based on these results, we suggest that the host inflammatory response and polymorphonuclear cell lysis contribute to a great extent to the central nervous system tissue damage.
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Affiliation(s)
- Isaac Cervantes-Sandoval
- Department of Experimental Pathology, Center for Research and Advanced Studies, National Polytechnic Institute, Mexico City, Mexico
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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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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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Abstract
Immune compromise can modify the severity and manifestation of some parasitic infections. More widespread use of newer immnosuppressive therapies, the growing population of individuals with immunocompromised states as well as the prolonged survival of these patients have altered the pattern of parasitic infection. This review article discusses the burden and immunology of parasitic infections in patients who are immunocompromised secondary to congenital immunodeficiency, malnutrition, malignancy, and immunosuppressive medications. This review does not address the literature on parasitic infections in the setting of HIV-1 infection.
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Affiliation(s)
- T Evering
- Department of Medicine (Division of Infectious Diseases), Albert Einstein College of Medicine, Bronx, New York 10461, USA
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