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Grubwieser P, Hilbe R, Gehrer CM, Grander M, Brigo N, Hoffmann A, Seifert M, Berger S, Theurl I, Nairz M, Weiss G. Klebsiella pneumoniae manipulates human macrophages to acquire iron. Front Microbiol 2023; 14:1223113. [PMID: 37637102 PMCID: PMC10451090 DOI: 10.3389/fmicb.2023.1223113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/17/2023] [Indexed: 08/29/2023] Open
Abstract
Background Klebsiella pneumoniae (KP) is a major cause of hospital-acquired infections, such as pneumonia. Moreover, it is classified as a pathogen of concern due to sprawling anti-microbial resistance. During infection, the gram-negative pathogen is capable of establishing an intracellular niche in macrophages by altering cellular metabolism. One factor critically affecting the host-pathogen interaction is the availability of essential nutrients, like iron, which is required for KP to proliferate but which also modulates anti-microbial immune effector pathways. We hypothesized, that KP manipulates macrophage iron homeostasis to acquire this crucial nutrient for sustained proliferation. Methods We applied an in-vitro infection model, in which human macrophage-like PMA-differentiated THP1 cells were infected with KP (strain ATCC 43816). During a 24-h course of infection, we quantified the number of intracellular bacteria via serial plating of cell lysates and evaluated the effects of different stimuli on intracellular bacterial numbers and iron acquisition. Furthermore, we analyzed host and pathogen specific gene and protein expression of key iron metabolism molecules. Results Viable bacteria are recovered from macrophage cell lysates during the course of infection, indicative of persistence of bacteria within host cells and inefficient pathogen clearing by macrophages. Strikingly, following KP infection macrophages strongly induce the expression of the main cellular iron importer transferrin-receptor-1 (TFR1). Accordingly, intracellular KP proliferation is further augmented by the addition of iron loaded transferrin. The induction of TFR1 is mediated via the STAT-6-IL-10 axis, and pharmacological inhibition of this pathway reduces macrophage iron uptake, elicits bacterial iron starvation, and decreases bacterial survival. Conclusion Our results suggest, that KP manipulates macrophage iron metabolism to acquire iron once confined inside the host cell and enforces intracellular bacterial persistence. This is facilitated by microbial mediated induction of TFR1 via the STAT-6-IL-10 axis. Mechanistic insights into immune metabolism will provide opportunities for the development of novel antimicrobial therapies.
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Affiliation(s)
- Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Richard Hilbe
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Clemens Michael Gehrer
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Manuel Grander
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
| | - Natascha Brigo
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Alexander Hoffmann
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
| | - Markus Seifert
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
| | - Sylvia Berger
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Igor Theurl
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pulmonology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
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Gehrer CM, Mitterstiller AM, Grubwieser P, Meyron-Holtz EG, Weiss G, Nairz M. Advances in Ferritin Physiology and Possible Implications in Bacterial Infection. Int J Mol Sci 2023; 24:4659. [PMID: 36902088 PMCID: PMC10003477 DOI: 10.3390/ijms24054659] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/17/2023] [Accepted: 02/25/2023] [Indexed: 03/04/2023] Open
Abstract
Due to its advantageous redox properties, iron plays an important role in the metabolism of nearly all life. However, these properties are not only a boon but also the bane of such life forms. Since labile iron results in the generation of reactive oxygen species by Fenton chemistry, iron is stored in a relatively safe form inside of ferritin. Despite the fact that the iron storage protein ferritin has been extensively researched, many of its physiological functions are hitherto unresolved. However, research regarding ferritin's functions is gaining momentum. For example, recent major discoveries on its secretion and distribution mechanisms have been made as well as the paradigm-changing finding of intracellular compartmentalization of ferritin via interaction with nuclear receptor coactivator 4 (NCOA4). In this review, we discuss established knowledge as well as these new findings and the implications they may have for host-pathogen interaction during bacterial infection.
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Affiliation(s)
- Clemens M. Gehrer
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Mitterstiller
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Esther G. Meyron-Holtz
- Laboratory of Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
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Pinto AT, Machado AB, Osório H, Pinto ML, Vitorino R, Justino G, Santa C, Castro F, Cruz T, Rodrigues C, Lima J, Sousa JLR, Cardoso AP, Figueira R, Monteiro A, Marques M, Manadas B, Pauwels J, Gevaert K, Mareel M, Rocha S, Duarte T, Oliveira MJ. Macrophage Resistance to Ionizing Radiation Exposure Is Accompanied by Decreased Cathepsin D and Increased Transferrin Receptor 1 Expression. Cancers (Basel) 2022; 15:270. [PMID: 36612268 PMCID: PMC9818572 DOI: 10.3390/cancers15010270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/06/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
PURPOSE To identify a molecular signature of macrophages exposed to clinically relevant ionizing radiation (IR) doses, mirroring radiotherapy sessions. METHODS Human monocyte-derived macrophages were exposed to 2 Gy/ fraction/ day for 5 days, mimicking one week of cancer patient's radiotherapy. Protein expression profile by proteomics was performed. RESULTS A gene ontology analysis revealed that radiation-induced protein changes are associated with metabolic alterations, which were further supported by a reduction of both cellular ATP levels and glucose uptake. Most of the radiation-induced deregulated targets exhibited a decreased expression, as was the case of cathepsin D, a lysosomal protease associated with cell death, which was validated by Western blot. We also found that irradiated macrophages exhibited an increased expression of the transferrin receptor 1 (TfR1), which is responsible for the uptake of transferrin-bound iron. TfR1 upregulation was also found in tumor-associated mouse macrophages upon tumor irradiation. In vitro irradiated macrophages also presented a trend for increased divalent metal transporter 1 (DMT1), which transports iron from the endosome to the cytosol, and a significant increase in iron release. CONCLUSIONS Irradiated macrophages present lower ATP levels and glucose uptake, and exhibit decreased cathepsin D expression, while increasing TfR1 expression and altering iron metabolism.
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Affiliation(s)
- Ana Teresa Pinto
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Ana Beatriz Machado
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
- Champalimaud Centre for the Unknown, Fundação Champalimaud, 1400-038 Lisboa, Portugal
| | - Hugo Osório
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IPATIMUP–Instituto de Patologia e Imunologia Molecular da Universidade do Porto, 4200-135 Porto, Portugal
- Departament of Pathology, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal
| | - Marta Laranjeiro Pinto
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Rui Vitorino
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Gonçalo Justino
- Centro de Química Estrutural–Institute of Molecular Sciences, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa, Portugal
| | - Cátia Santa
- CNC–Center for Neuroscience and Cell Biology, Universidade de Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), Universidade de Coimbra, 3030-789 Coimbra, Portugal
| | - Flávia Castro
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Tânia Cruz
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Carla Rodrigues
- REQUIMTE–LAQV, Chemistry Department, NOVA School of Science and Technology, Universidade de Lisboa, 2829-516 Caparica, Portugal
| | - Jorge Lima
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IPATIMUP–Instituto de Patologia e Imunologia Molecular da Universidade do Porto, 4200-135 Porto, Portugal
| | - José Luís R. Sousa
- Personal Health Data Science Group, Sano-Centre for Computational Personalised Medicine, 30-054 Krakow, Poland
| | - Ana Patrícia Cardoso
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Rita Figueira
- Radiotherapy Service, Centro Hospitalar Universitário São João (CHUSJ), EPE, 4200-319 Porto, Portugal
| | - Armanda Monteiro
- Radiotherapy Service, Centro Hospitalar Universitário São João (CHUSJ), EPE, 4200-319 Porto, Portugal
| | - Margarida Marques
- Radiotherapy Service, Centro Hospitalar Universitário São João (CHUSJ), EPE, 4200-319 Porto, Portugal
| | - Bruno Manadas
- Institute for Interdisciplinary Research (III), Universidade de Coimbra, 3030-789 Coimbra, Portugal
| | - Jarne Pauwels
- VIB-UGent Center for Medical Biotechnology, 9052 Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, 9052 Ghent, Belgium
| | - Kris Gevaert
- VIB-UGent Center for Medical Biotechnology, 9052 Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, 9052 Ghent, Belgium
| | - Marc Mareel
- Department of Radiation Oncology and Experimental Cancer Research, Ghent University Hospital, 9000 Ghent, Belgium
| | - Sónia Rocha
- Institute of System, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3 GE, UK
| | - Tiago Duarte
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC–Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Maria José Oliveira
- i3S–Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- INEB–Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
- Departament of Pathology, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal
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Grubwieser P, Hoffmann A, Hilbe R, Seifert M, Sonnweber T, Böck N, Theurl I, Weiss G, Nairz M. Airway Epithelial Cells Differentially Adapt Their Iron Metabolism to Infection With Klebsiella pneumoniae and Escherichia coli In Vitro. Front Cell Infect Microbiol 2022; 12:875543. [PMID: 35663465 PMCID: PMC9157649 DOI: 10.3389/fcimb.2022.875543] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/22/2022] [Indexed: 12/13/2022] Open
Abstract
Background Pneumonia is often elicited by bacteria and can be associated with a severe clinical course, respiratory failure and the need for mechanical ventilation. In the alveolus, type-2-alveolar-epithelial-cells (AECII) contribute to innate immune functions. We hypothesized that AECII actively adapt cellular iron homeostasis to restrict this essential nutrient from invading pathogens - a defense strategy termed 'nutritional immunity', hitherto mainly demonstrated for myeloid cells. Methods We established an in-vitro infection model using the human AECII-like cell line A549. We infected cells with Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli), two gram-negative bacteria with different modes of infection and frequent causes of hospital-acquired pneumonia. We followed the entry and intracellular growth of these gram-negative bacteria and analyzed differential gene expression and protein levels of key inflammatory and iron metabolism molecules. Results Both, K. pneumoniae and E. coli are able to invade A549 cells, whereas only K. pneumoniae is capable of proliferating intracellularly. After peak bacterial burden, the number of intracellular pathogens declines, suggesting that epithelial cells initiate antimicrobial immune effector pathways to combat bacterial proliferation. The extracellular pathogen E. coli induces an iron retention phenotype in A549 cells, mainly characterized by the downregulation of the pivotal iron exporter ferroportin, the upregulation of the iron importer transferrin-receptor-1 and corresponding induction of the iron storage protein ferritin. In contrast, cells infected with the facultative intracellular bacterium K. pneumoniae exhibit an iron export phenotype indicated by ferroportin upregulation. This differential regulation of iron homeostasis and the pathogen-specific inflammatory reaction is likely mediated by oxidative stress. Conclusion AECII-derived A549 cells show pathogen-specific innate immune functions and adapt their iron handling in response to infection. The differential regulation of iron transporters depends on the preferential intra- or extracellular localization of the pathogen and likely aims at limiting bacterial iron availability.
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Affiliation(s)
- Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Alexander Hoffmann
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
| | - Richard Hilbe
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Markus Seifert
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Sonnweber
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Nina Böck
- Biocenter, Institute of Bioinformatics, Medical University of Innsbruck, Innsbruck, Austria
| | - Igor Theurl
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, Innsbruck, Austria
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Ferrous Iron Uptake Is Required for Salmonella to Persist within Vacuoles of Host Cells. Infect Immun 2022; 90:e0014922. [PMID: 35536027 DOI: 10.1128/iai.00149-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Iron is an essential oligoelement that incorporates into proteins as a biocatalyst or electron carrier. The intracellular pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) takes iron as free reduced ferrous cation or as oxidized ferric cation complexed to siderophores or ferrichromes. Deficiencies in ferrous or ferric iron uptake attenuate S. Typhimurium virulence, but how the uptake systems are used in the intracellular environment remains poorly understood. Here, using S. Typhimurium mutants deficient in multiple iron uptake systems, we show that SitABCD and FeoABC, involved in ferrous iron uptake, are central for this pathogen to persist within vacuoles of fibroblasts. Assays at the protein level showed that components of these two uptake systems, SitD and FeoB, are produced at high levels by intravacuolar bacteria. Despite not being essential for viability inside the vacuole, intracellular bacteria also upregulate transporters involved in ferric iron uptake such as IroN, FepA, and CirA. In addition, an unprecedented cleavage at the N-terminal region of FepA was observed as a distinctive feature of nonproliferating intravacuolar bacteria. Collectively, our findings indicate that SitABCD and FeoABC contribute to S. Typhimurium virulence by promoting iron acquisition within the vacuolar compartment.
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Abstract
Iron limitation is a universal strategy of host immunity during bacterial infection. However, the mechanisms by which pathogens antagonize host nutritional immunity have not been fully elucidated. Here, we identified a requirement for the UMPylator YdiU for this process in Salmonella. The expression of YdiU was dramatically induced by the metal starvation signal. The intracellular iron content was much lower in the ΔydiU strain than in wild-type Salmonella, and the ΔydiU strain exhibited severe growth defect under metal deficiency environments. Genome-wide expression analyses revealed significantly decreased expression of iron uptake genes in ΔydiU strain compared with the wild-type strain. Interestingly, YdiU did not affect the expression level of the major iron uptake regulator Fur but directly UMPylated Fur on its H118 residue in vivo and in vitro. UMPylation destroyed the Fur dimer, promoted Fur aggregation, and eliminated the DNA-binding activity of Fur, thus abolishing the ability of Fur to inhibit iron uptake. Restricting Fur to the deUMPylated state dramatically eliminates Salmonella iron uptake in iron deficiency environments. In parallel, YdiU facilitates Salmonella survival within host cells by regulating the iron uptake pathway.
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Martínez DP, Oliver C, Santibañez N, Coronado JL, Oyarzún-Salazar R, Enriquez R, Vargas-Chacoff L, Romero A. PAMPs of Piscirickettsia salmonis Trigger the Transcription of Genes Involved in Nutritional Immunity in a Salmon Macrophage-Like Cell Line. Front Immunol 2022; 13:849752. [PMID: 35493529 PMCID: PMC9046600 DOI: 10.3389/fimmu.2022.849752] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
The innate immune system can limit the growth of invading pathogens by depleting micronutrients at a cellular and tissue level. However, it is not known whether nutrient depletion mechanisms discriminate between living pathogens (which require nutrients) and pathogen-associated molecular patterns (PAMPs) (which do not). We stimulated SHK-1 cells with different PAMPs (outer membrane vesicles of Piscirickettsia salmonis “OMVs”, protein extract of P. salmonis “TP” and lipopolysaccharides of P. salmonis “LPS”) isolated from P. salmonis and evaluated transcriptional changes in nutritional immunity associated genes. Our experimental treatments were: Control (SHK-1 stimulated with bacterial culture medium), OMVs (SHK-1 stimulated with 1μg of outer membrane vesicles), TP (SHK-1 stimulated with 1μg of total protein extract) and LPS (SHK-1 stimulated with 1μg of lipopolysaccharides). Cells were sampled at 15-, 30-, 60- and 120-minutes post-stimulation. We detected increased transcription of zip8, zip14, irp1, irp2 and tfr1 in all three experimental conditions and increased transcription of dmt1 in cells stimulated with OMVs and TP, but not LPS. Additionally, we observed generally increased transcription of ireg-1, il-6, hamp, irp1, ft-h and ft-m in all three experimental conditions, but we also detected decreased transcription of these markers in cells stimulated with TP and LPS at specific time points. Our results demonstrate that SHK-1 cells stimulated with P. salmonis PAMPs increase transcription of markers involved in the transport, uptake, storage and regulation of micronutrients such as iron, manganese and zinc.
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Affiliation(s)
- Danixa Pamela Martínez
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Laboratorio de Fisiología de peces, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- *Correspondence: Danixa Pamela Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
| | - Cristian Oliver
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Natacha Santibañez
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - José Leonardo Coronado
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Ricardo Oyarzún-Salazar
- Laboratorio de Fisiología de peces, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Ricardo Enriquez
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Luis Vargas-Chacoff
- Laboratorio de Fisiología de peces, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems, BASE, University Austral of Chile, Valdivia, Chile
- *Correspondence: Danixa Pamela Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
| | - Alex Romero
- Laboratorio de Inmunología y estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Austral de Chile, Valdivia, Chile
- *Correspondence: Danixa Pamela Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
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Iron Reduction in Dermacentor andersoni Tick Cells Inhibits Anaplasma marginale Replication. Int J Mol Sci 2022; 23:ijms23073941. [PMID: 35409307 PMCID: PMC8999750 DOI: 10.3390/ijms23073941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/23/2022] [Accepted: 03/29/2022] [Indexed: 02/04/2023] Open
Abstract
Anaplasma spp. are obligate intracellular, tick-borne, bacterial pathogens that cause bovine and human anaplasmosis. We lack tools to prevent these diseases in part due to major knowledge gaps in our fundamental understanding of the tick-pathogen interface, including the requirement for and molecules involved in iron transport during tick colonization. We determine that iron is required for the pathogen Anaplasma marginale, which causes bovine anaplasmosis, to replicate in Dermacentor andersoni tick cells. Using bioinformatics and protein modeling, we identified three orthologs of the Gram-negative siderophore-independent iron uptake system, FbpABC. Am069, the A. marginale ortholog of FbpA, lacks predicted iron-binding residues according to the NCBI conserved domain database. However, according to protein modeling, the best structural orthologs of Am069 are iron transport proteins from Cyanobacteria and Campylobacterjejuni. We then determined that all three A. marginale genes are modestly differentially expressed in response to altered host cell iron levels, despite the lack of a Ferric uptake regulator or operon structure. This work is foundational for building a mechanistic understanding of iron uptake, which could lead to interventions to prevent bovine and human anaplasmosis.
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Valenzuela-Muñoz V, Benavente BP, Casuso A, Leal Y, Valenzuela-Miranda D, Núñez-Acuña G, Sáez-Vera C, Gallardo-Escárate C. Transcriptome and morphological analysis in Caligus rogercresseyi uncover the effects of Atlantic salmon vaccination with IPath®. FISH & SHELLFISH IMMUNOLOGY 2021; 117:169-178. [PMID: 34389379 DOI: 10.1016/j.fsi.2021.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
It is known that iron transporter proteins and their regulation can modulate the fish's immune system, suggesting these proteins as a potential candidate for fish vaccines. Previous studies have evidenced the effects of Atlantic salmon immunized with the chimeric iron-related protein named IPath® against bacterial and ectoparasitic infections. The present study aimed to explore the transcriptome modulation and the morphology of the sea louse Caligus rogercresseyi in response to Atlantic salmon injected with IPath®. Herein, Atlantic salmon were injected with IPath® and challenged to sea lice in controlled laboratory conditions. Then, female adults were collected after 25 days post-infection for molecular and morphological evaluation. Transcriptome analysis conducted in lice collected from immunized fish revealed high modulation of transcripts compared with the control groups. Notably, the low number of up/downregulated transcripts was mainly found in lice exposed to the IPath® fish group. Among the top-25 differentially expressed genes, Vitellogenin, Cytochrome oxidases, and proteases genes were strongly downregulated, suggesting that IPath® can alter lipid transport, hydrogen ion transmembrane transport, and proteolysis. The morphological analysis in lice collected from IPath® fish revealed abnormal embryogenesis and inflammatory processes of the genital segment. Furthermore, head kidney, spleen, and skin were also analyzed in immunized fish to evaluate the transcription expression of immune and iron homeostasis-related genes. The results showed downregulation of TLR22, MCHII, IL-1β, ALAs, HO, BLVr, GSHPx, and Ferritin genes in head kidney and skin tissues; meanwhile, those genes did not show significant differences in spleen tissue. Overall, our findings suggest that IPath® can be used to enhance the fish immune response, showing a promissory commercial application against lice infections.
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Affiliation(s)
- Valentina Valenzuela-Muñoz
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Bárbara P Benavente
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Antonio Casuso
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Yeny Leal
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Diego Valenzuela-Miranda
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Gustavo Núñez-Acuña
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Constanza Sáez-Vera
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile
| | - Cristian Gallardo-Escárate
- Interdisciplinary Center for Aquaculture Research (INCAR), University of Concepción, Concepción, Chile; Laboratory of Biotechnology and Aquatic Genomics, Department of Oceanography, University of Concepción, Concepción, Chile.
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Chimeric Protein IPath ® with Chelating Activity Improves Atlantic Salmon's Immunity against Infectious Diseases. Vaccines (Basel) 2021; 9:vaccines9040361. [PMID: 33918540 PMCID: PMC8068967 DOI: 10.3390/vaccines9040361] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
Infection processes displayed by pathogens require the acquisition of essential inorganic nutrients and trace elements from the host to survive and proliferate. Without a doubt, iron is a crucial trace metal for all living organisms and also a pivotal component in the host–parasite interactions. In particular, the host reduces the iron available to face the infectious disease, increasing iron transport proteins’ expression and activating the heme synthesis and degradation pathways. Moreover, recent findings have suggested that iron metabolism modulation in fish promotes the immune response by reducing cellular iron toxicity. We hypothesized that recombinant proteins related to iron metabolism could modulate the fish’s immune system through iron metabolism and iron-responsive genes. Here a chimeric iron transport protein (IPath®) was bioinformatically designed and then expressed in a recombinant bacterial system. The IPath® protein showed a significant chelating activity under in vitro conditions and biological activity. Taking this evidence, a vaccine candidate based on IPath® was evaluated in Atlantic salmon challenged with three different fish pathogens. Experimental trials were conducted using two fish groups: one immunized with IPath® and another injected with adjutant as the control group. After 400 accumulated thermal units (ATUs), two different infection trials were performed. In the first one, fish were infected with the bacterium Aeromonas salmonicida, and in a second trial, fish were exposed to the ectoparasite Caligus rogercresseyi and subsequently infected with the intracellular bacterium Piscirickettsia salmonis. Fish immunized with IPath® showed a significant delay in the mortality curve in response to A. salmonicida and P. salmonis infections. However, no significant differences between infected and control fish groups were observed at the end of the experiment. Notably, sea lice burden reduction was observed in vaccinated Atlantic salmon. Transcriptional analysis evidenced a high modulation of iron-homeostasis-related genes in fish vaccinated with IPath® compared to the control group during the infection. Moreover, increasing expression of Atlantic salmon IgT was associated with IPath® immunization. This study provides evidence that the IPath® protein could be used as an antigen or booster in commercial fish vaccines, improving the immune response against relevant pathogens for salmon aquaculture.
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Mechanisms Affecting the Acquisition, Persistence and Transmission of Francisella tularensis in Ticks. Microorganisms 2020; 8:microorganisms8111639. [PMID: 33114018 PMCID: PMC7690693 DOI: 10.3390/microorganisms8111639] [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: 09/29/2020] [Revised: 10/15/2020] [Accepted: 10/21/2020] [Indexed: 01/06/2023] Open
Abstract
Over 600,000 vector-borne disease cases were reported in the United States (U.S.) in the past 13 years, of which more than three-quarters were tick-borne diseases. Although Lyme disease accounts for the majority of tick-borne disease cases in the U.S., tularemia cases have been increasing over the past decade, with >220 cases reported yearly. However, when comparing Borrelia burgdorferi (causative agent of Lyme disease) and Francisella tularensis (causative agent of tularemia), the low infectious dose (<10 bacteria), high morbidity and mortality rates, and potential transmission of tularemia by multiple tick vectors have raised national concerns about future tularemia outbreaks. Despite these concerns, little is known about how F. tularensis is acquired by, persists in, or is transmitted by ticks. Moreover, the role of one or more tick vectors in transmitting F. tularensis to humans remains a major question. Finally, virtually no studies have examined how F. tularensis adapts to life in the tick (vs. the mammalian host), how tick endosymbionts affect F. tularensis infections, or whether other factors (e.g., tick immunity) impact the ability of F. tularensis to infect ticks. This review will assess our current understanding of each of these issues and will offer a framework for future studies, which could help us better understand tularemia and other tick-borne diseases.
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12
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Control of Francisella tularensis Virulence at Gene Level: Network of Transcription Factors. Microorganisms 2020; 8:microorganisms8101622. [PMID: 33096715 PMCID: PMC7588896 DOI: 10.3390/microorganisms8101622] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/14/2020] [Accepted: 10/18/2020] [Indexed: 02/07/2023] Open
Abstract
Regulation of gene transcription is the initial step in the complex process that controls gene expression within bacteria. Transcriptional control involves the joint effort of RNA polymerases and numerous other regulatory factors. Whether global or local, positive or negative, regulators play an essential role in the bacterial cell. For instance, some regulators specifically modify the transcription of virulence genes, thereby being indispensable to pathogenic bacteria. Here, we provide a comprehensive overview of important transcription factors and DNA-binding proteins described for the virulent bacterium Francisella tularensis, the causative agent of tularemia. This is an unexplored research area, and the poorly described networks of transcription factors merit additional experimental studies to help elucidate the molecular mechanisms of pathogenesis in this bacterium, and how they contribute to disease.
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13
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How Severe Anaemia Might Influence the Risk of Invasive Bacterial Infections in African Children. Int J Mol Sci 2020; 21:ijms21186976. [PMID: 32972031 PMCID: PMC7555399 DOI: 10.3390/ijms21186976] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/04/2020] [Accepted: 09/15/2020] [Indexed: 12/21/2022] Open
Abstract
Severe anaemia and invasive bacterial infections are common causes of childhood sickness and death in sub-Saharan Africa. Accumulating evidence suggests that severely anaemic African children may have a higher risk of invasive bacterial infections. However, the mechanisms underlying this association remain poorly described. Severe anaemia is characterized by increased haemolysis, erythropoietic drive, gut permeability, and disruption of immune regulatory systems. These pathways are associated with dysregulation of iron homeostasis, including the downregulation of the hepatic hormone hepcidin. Increased haemolysis and low hepcidin levels potentially increase plasma, tissue and intracellular iron levels. Pathogenic bacteria require iron and/or haem to proliferate and have evolved numerous strategies to acquire labile and protein-bound iron/haem. In this review, we discuss how severe anaemia may mediate the risk of invasive bacterial infections through dysregulation of hepcidin and/or iron homeostasis, and potential studies that could be conducted to test this hypothesis.
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14
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Ghio AJ, Soukup JM, Dailey LA, Madden MC. Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury. Free Radic Biol Med 2020; 151:38-55. [PMID: 32092410 PMCID: PMC8274387 DOI: 10.1016/j.freeradbiomed.2020.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.
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Affiliation(s)
- Andrew J Ghio
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA.
| | - Joleen M Soukup
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Lisa A Dailey
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
| | - Michael C Madden
- From the National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, NC, USA
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15
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Alizadeh K, Sun Q, McGuire T, Thompson T, Prato FS, Koropatnick J, Gelman N, Goldhawk DE. Hepcidin-mediated Iron Regulation in P19 Cells is Detectable by Magnetic Resonance Imaging. Sci Rep 2020; 10:3163. [PMID: 32081948 PMCID: PMC7035373 DOI: 10.1038/s41598-020-59991-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 02/04/2020] [Indexed: 01/25/2023] Open
Abstract
Magnetic resonance imaging can be used to track cellular activities in the body using iron-based contrast agents. However, multiple intrinsic cellular iron handling mechanisms may also influence the detection of magnetic resonance (MR) contrast: a need to differentiate among those mechanisms exists. In hepcidin-mediated inflammation, for example, downregulation of iron export in monocytes and macrophages involves post-translational degradation of ferroportin. We examined the influence of hepcidin endocrine activity on iron regulation and MR transverse relaxation rates in multi-potent P19 cells, which display high iron import and export activities, similar to alternatively-activated macrophages. Iron import and export were examined in cultured P19 cells in the presence and absence of iron-supplemented medium, respectively. Western blots indicated the levels of transferrin receptor, ferroportin and ubiquitin in the presence and absence of extracellular hepcidin. Total cellular iron was measured by inductively-coupled plasma mass spectrometry and correlated to transverse relaxation rates at 3 Tesla using a gelatin phantom. Under varying conditions of iron supplementation, the level of ferroportin in P19 cells responds to hepcidin regulation, consistent with degradation through a ubiquitin-mediated pathway. This response of P19 cells to hepcidin is similar to that of classically-activated macrophages. The correlation between total cellular iron content and MR transverse relaxation rates was different in hepcidin-treated and untreated P19 cells: slope, Pearson correlation coefficient and relaxation rate were all affected. These findings may provide a tool to non-invasively distinguish changes in endogenous iron contrast arising from hepcidin-ferroportin interactions, with potential utility in monitoring of different macrophage phenotypes involved in pro- and anti-inflammatory signaling. In addition, this work demonstrates that transverse relaxivity is not only influenced by the amount of cellular iron but also by its metabolism.
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Affiliation(s)
- Kobra Alizadeh
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Qin Sun
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
| | - Tabitha McGuire
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
| | - Terry Thompson
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Frank S Prato
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
- Physics and Astronomy, Western University, London, Ontario, Canada
| | - Jim Koropatnick
- London Regional Cancer Program, London, Ontario, Canada
- Oncology, Western University, London, Ontario, Canada
| | - Neil Gelman
- Imaging, Lawson Health Research Institute, London, Ontario, Canada
- Medical Biophysics, Western University, London, Ontario, Canada
- Medical Imaging, Western University, London, Ontario, Canada
| | - Donna E Goldhawk
- Imaging, Lawson Health Research Institute, London, Ontario, Canada.
- Medical Biophysics, Western University, London, Ontario, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Ontario, Canada.
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16
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Dighal A, Mukhopadhyay D, Sengupta R, Moulik S, Mukherjee S, Roy S, Chaudhuri SJ, Das NK, Chatterjee M. Iron trafficking in patients with Indian Post kala-azar dermal leishmaniasis. PLoS Negl Trop Dis 2020; 14:e0007991. [PMID: 32023254 PMCID: PMC7001907 DOI: 10.1371/journal.pntd.0007991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 12/12/2019] [Indexed: 12/19/2022] Open
Abstract
Background During infections involving intracellular pathogens, iron performs a double-edged function by providing the pathogen with nutrients, but also boosts the host’s antimicrobial arsenal. Although the role of iron has been described in visceral leishmaniasis, information regarding its status in the dermal sequel, Post Kala-azar Dermal Leishmaniasis (PKDL) remains limited. Accordingly, this study aimed to establish the status of iron within monocytes/macrophages of PKDL cases. Methodology/Principal findings The intramonocytic labile iron pool (LIP), status of CD163 (hemoglobin-haptoglobin scavenging receptor) and CD71 (transferrin receptor, Tfr) were evaluated within CD14+ monocytes by flow cytometry, and soluble CD163 by ELISA. At the lesional sites, Fe3+ status was evaluated by Prussian blue staining, parasite load by qPCR, while the mRNA expression of Tfr (TfR1/CD71), CD163, divalent metal transporter-1 (DMT-1), Lipocalin-2 (Lcn-2), Heme-oxygenase-1 (HO-1), Ferritin, Natural resistance-associated macrophage protein (NRAMP-1) and Ferroportin (Fpn-1) was evaluated by droplet digital PCR. Circulating monocytes demonstrated elevated levels of CD71, CD163 and soluble CD163, which corroborated with an enhanced lesional mRNA expression of TfR, CD163, DMT1 and Lcn-2. Additionally, the LIP was raised along with an elevated mRNA expression of ferritin and HO-1, as also iron exporters NRAMP-1 and Fpn-1. Conclusions/Significance In monocytes/macrophages of PKDL cases, enhancement of the iron influx gateways (TfR, CD163, DMT-1 and Lcn-2) possibly accounted for the enhanced LIP. However, enhancement of the iron exporters (NRAMP-1 and Fpn-1) defied the classical Ferritinlow/Ferroportinhigh phenotype of alternatively activated macrophages. The creation of such a pro-parasitic environment suggests incorporation of chemotherapeutic strategies wherein the availability of iron to the parasite can be restricted. Post kala-azar dermal leishmaniasis (PKDL), a dermal sequel of Visceral Leishmaniasis (VL) is caused by the digenetic protozoan parasite Leishmania donovani. The parasite infects humans and replicates intracellularly within macrophages, cells normally engaged in protecting the host from pathogens. Iron plays a crucial role in microbes and mammalian cells, being needed by the former for its growth and survival, while the latter uses it for activation of the immune system by facilitating generation of reactive oxygen species. Therefore, the availability of iron needs to be tightly regulated to ensure its accessibility for core biological functions, and yet prevent its utilization by intracellular pathogens. Here we investigated the status of intra-macrophage iron along with expression of its transporters in patients with PKDL. Our study suggests that within monocytes/macrophages there is an enhanced entry of iron via the upregulation of CD71 and CD163 that translates into an enhanced labile iron pool and Ferritin. However, the concomitant increase in expression of iron exporters NRAMP-1 and Fpn-1 suggested the host’s attempt to deny the pathogen access to iron. This Ferritinhigh/Ferroportinhigh phenotype was in contrast to the conventional Ferritinlow/Ferroportinhigh phenotype present in alternatively activated M2 macrophages. Taken together, the control of iron homeostasis is one of the contributors in the host-pathogen interplay as it influences the course of an infectious disease by favouring either the mammalian host or the invading pathogen.
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MESH Headings
- Adolescent
- Adult
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Antigens, Differentiation, Myelomonocytic/genetics
- Antigens, Differentiation, Myelomonocytic/metabolism
- Cation Transport Proteins/genetics
- Cation Transport Proteins/metabolism
- Female
- Humans
- India
- Iron/metabolism
- Leishmania donovani/drug effects
- Leishmania donovani/physiology
- Leishmaniasis, Cutaneous/metabolism
- Leishmaniasis, Cutaneous/parasitology
- Lipocalin-2/genetics
- Lipocalin-2/metabolism
- Macrophages/metabolism
- Male
- Monocytes/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Transferrin/genetics
- Receptors, Transferrin/metabolism
- Young Adult
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Affiliation(s)
- Aishwarya Dighal
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Debanjan Mukhopadhyay
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Ritika Sengupta
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Srija Moulik
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Shibabrata Mukherjee
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Susmita Roy
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | | | - Nilay K. Das
- Dept of Dermatology, Bankura Sammilani Medical College, Bankura, India
| | - Mitali Chatterjee
- Dept. of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
- * E-mail:
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EntE, EntS and TolC synergistically contributed to the pathogenesis of APEC strain E058. Microb Pathog 2020; 141:103990. [PMID: 31978427 DOI: 10.1016/j.micpath.2020.103990] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 01/19/2020] [Accepted: 01/20/2020] [Indexed: 01/18/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) shows an enhanced ability to cause infection outside the intestinal tract. Avian pathogenic E. coli (APEC), one type of ExPEC, causes avian colibacillosis, a disease of significant economic importance to poultry producers worldwide that is characterized by systemic infection. Some ExPEC strains as well as other pathogenic enterobacteria produce enterobactin, a catecholate siderophore used to sequester iron during infection. Here, we showed that disruption of enterobactin efflux via outer membrane protein TolC significantly decreased the pathogenicity of APEC strain E058. Furthermore, colonization and persistence assays performed using a chicken infection model showed that the ΔtolC mutant was obviously attenuated (p˂0.001). In contrast, disruption of enterobactin synthesis gene entE and/or the inner membrane transporter gene entS had little effect on pathogenicity. Analysis of growth kinetics revealed a significant reduction in the growth of triple mutant strain E058ΔentEΔentSΔtolC in iron-deficient medium compared with the wild-type strain (p˂0.001), while no growth impairment was noted for the E058ΔtolC mutant in either Luria-Bertani broth or iron-deficient medium. The E058ΔentEΔentSΔtolC mutant also showed significantly decreased virulence compared with single mutant strain E058ΔtolC. Low-copy complementation of strains E058ΔtolC and E058ΔentEΔentSΔtolC with plasmid-borne tolC restored virulence to wild-type levels in the chicken infection model. Macrophage infection assays showed that ingestion of E058ΔtolC by macrophage cell line HD11 cells was reduced compared with ingestion of the E058ΔentEΔentSΔtolC mutant. However, no significant differences were observed between the mutants and the wild-type in a chicken serum resistance assay. Together, these results suggest that EntE, EntS and TolC synergistically contributed to the pathogenesis of APEC strain E058 in an iron-deficient environment.
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18
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Structure and Metal Binding Properties of Chlamydia trachomatis YtgA. J Bacteriol 2019; 202:JB.00580-19. [PMID: 31611288 DOI: 10.1128/jb.00580-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022] Open
Abstract
The obligate intracellular pathogen Chlamydia trachomatis is a globally significant cause of sexually transmitted bacterial infections and the leading etiological agent of preventable blindness. The first-row transition metal iron (Fe) plays critical roles in chlamydial cell biology, and acquisition of this nutrient is essential for the survival and virulence of the pathogen. Nevertheless, how C. trachomatis acquires Fe from host cells is not well understood, since it lacks genes encoding known siderophore biosynthetic pathways, receptors for host Fe storage proteins, and the Fe acquisition machinery common to many bacteria. Recent studies have suggested that C. trachomatis directly acquires host Fe via the ATP-binding cassette permease YtgABCD. Here, we characterized YtgA, the periplasmic solute binding protein component of the transport pathway, which has been implicated in scavenging Fe(III) ions. The structure of Fe(III)-bound YtgA was determined at 2.0-Å resolution with the bound ion coordinated via a novel geometry (3 Ns, 2 Os [3N2O]). This unusual coordination suggested a highly plastic metal binding site in YtgA capable of interacting with other cations. Biochemical analyses showed that the metal binding site of YtgA was not restricted to interaction with only Fe(III) ions but could bind all transition metal ions examined. However, only Mn(II), Fe(II), and Ni(II) ions bound reversibly to YtgA, with Fe being the most abundant cellular transition metal in C. trachomatis Collectively, these findings show that YtgA is the metal-recruiting component of the YtgABCD permease and is most likely involved in the acquisition of Fe(II) and Mn(II) from host cells.IMPORTANCE Chlamydia trachomatis is the most common bacterial sexually transmitted infection in developed countries, with an estimated global prevalence of 4.2% in the 15- to 49-year age group. Although infection is asymptomatic in more than 80% of infected women, about 10% of cases result in serious disease. Infection by C. trachomatis is dependent on the ability to acquire essential nutrients, such as the transition metal iron, from host cells. In this study, we show that iron is the most abundant transition metal in C. trachomatis and report the structural and biochemical properties of the iron-recruiting protein YtgA. Knowledge of the high-resolution structure of YtgA will provide a platform for future structure-based antimicrobial design approaches.
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19
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Ghio AJ, Soukup JM, Stonehuerner J, Tong H, Richards J, Gilmour MI, Madden MC, Shen Z, Kantrow SP. Quartz Disrupts Iron Homeostasis in Alveolar Macrophages To Impact a Pro-Inflammatory Effect. Chem Res Toxicol 2019; 32:1737-1747. [PMID: 31407890 DOI: 10.1021/acs.chemrestox.8b00301] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The biological response of bronchial epithelial cells to particles is associated with a sequestration of cell metal by the particle surface and a subsequent disruption in host iron homeostasis. The macrophage is the cell type resident in the respiratory tract that is most likely to make initial contact with inhaled particles. We tested the postulates that (1) silica, a prototypical particle, disrupts iron homeostasis in alveolar macrophages (AMs); and (2) the altered iron homeostasis results in both an oxidative stress and pro-inflammatory effects. Human AMs (1.0 × 106/mL) demonstrated an increased import of iron following particle exposure with nonheme iron concentrations of 0.57 ± 0.03, 1.72 ± 0.09, 0.88 ± 0.09, and 3.21 ± 0.11 ppm in cells exposed for 4 h to media, 500 μM ferric ammonium citrate (FAC), 100 μg/mL silica, and both silica and FAC, respectively. Intracellular ferritin concentrations and iron release were similarly increased after AM exposure to FAC and silica. Silica increased oxidant generation by AMs measured using both dichlorofluorescein diacetate fluorescence and reduction of nitroblue tetrazolium salt. Concentrations of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α in macrophage supernatant increased following 100 μg/mL silica exposure for 24 h. Treatment of AMs with 500 μM FAC decreased both oxidant generation and cytokine release associated with silica exposure, supporting a dependence of these effects on sequestration of cell metal by the particle surface. We conclude that (1) silica exposure disrupts iron homeostasis resulting in increased import, accumulation, and release of the metal; and (2) the altered iron homeostasis following silica exposure impacts oxidant generation and pro-inflammatory effects.
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Affiliation(s)
- Andrew J Ghio
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Joleen M Soukup
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Jacqueline Stonehuerner
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Haiyan Tong
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Judy Richards
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - M Ian Gilmour
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Michael C Madden
- National Health and Environmental Effects Research Laboratory , Environmental Protection Agency , Chapel Hill North Carolina 27514 , United States
| | - Zhiwei Shen
- Section of Pulmonary and Critical Care Medicine, Department of Medicine , Louisiana State University Health Sciences Center , New Orleans , Louisiana 70112 , United States
| | - Stephen P Kantrow
- Section of Pulmonary and Critical Care Medicine, Department of Medicine , Louisiana State University Health Sciences Center , New Orleans , Louisiana 70112 , United States
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Wang Y, Cai Y, Zhang J, Liu D, Gong X, Pan Z, Geng S, Jiao X. Controversy Surrounding the Function of SpiC Protein in Salmonella: An Overview. Front Microbiol 2019; 10:1784. [PMID: 31440219 PMCID: PMC6693482 DOI: 10.3389/fmicb.2019.01784] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/18/2019] [Indexed: 01/19/2023] Open
Abstract
Salmonella is an important pathogenic microorganism that can infect humans and animals and has been studied globally as a model microorganism for its pathogenesis. The SpiC protein of T3SS2 is a significant factor that has been studied for almost 20 years, but to date, the function/effect of SpiC in the pathogenesis of Salmonella has not been completely understood. There is controversy over the functions of SpiC protein in the literature. Thus, an overview of the literature on SpiC protein is provided here which highlights expression features of SpiC protein and its various functions and effect.
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Affiliation(s)
- Yaonan Wang
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Yuan Cai
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Jian Zhang
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Dong Liu
- Research and Development Center, State Key Laboratory of Genetically Engineered Veterinary Vaccines, Yebio Bioengineering Co., Ltd of Qingdao, Qingdao, China
| | - Xiao Gong
- Research and Development Center, State Key Laboratory of Genetically Engineered Veterinary Vaccines, Yebio Bioengineering Co., Ltd of Qingdao, Qingdao, China
| | - Zhiming Pan
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Shizhong Geng
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Xin'an Jiao
- College of Bioscience and Biotechnology and College of Veterinary Medicine, Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
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Tiwari V, Rajeswari MR, Tiwari M. Proteomic analysis of iron-regulated membrane proteins identify FhuE receptor as a target to inhibit siderophore-mediated iron acquisition in Acinetobacter baumannii. Int J Biol Macromol 2018; 125:1156-1167. [PMID: 30579900 DOI: 10.1016/j.ijbiomac.2018.12.173] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/02/2018] [Accepted: 12/19/2018] [Indexed: 11/27/2022]
Abstract
Survival of the Acinetobacter baumannii inside host requires different micronutrients such as iron, but their bioavailability is limited because of nutritional immunity created by host. A. baumannii has to develop mechanisms to acquire nutrient iron during infection. The present study is an attempt to identify membrane proteins involved in iron sequestration mechanism of A. baumannii using two-dimensional electrophoresis and LC-MS/MS analysis. The identified iron-regulated membrane protein (IRMP) of A. baumannii was used for its interaction studies with different siderophores, and designing of the inhibitor against A. baumannii targeting this IRMP. Membrane proteomic results identified over-expression of four membrane proteins (Fhu-E receptor, ferric-acinetobactin receptor, ferrienterochelin receptor, and ferric siderophore receptor) under iron-limited condition. A. baumannii produces siderophores that have good interaction with the FhuE receptor. Result also showed that FhuE receptor has interaction with siderophores produced by other bacteria. Interaction of FhuE receptor and siderophores helps in iron sequestration and survival of Acinetobacter under nutritional immunity imposed by the host. Hence it becomes essential to find a potential inhibitor for the FhuE receptor that can inhibit the survival of A. baumannii in the host. In-silico screening, and molecular mechanics studies identified ZINC03794794 and ZINC01530652 as a likely lead to design inhibitor against the FhuE receptor of A. baumannii. The designed inhibitor is experimentally validated for its antibacterial activity on the A. baumannii. Therefore, designed inhibitor interferes with the iron acquisition mechanism of Acinetobacter hence may prove useful for preventing infection caused by A. baumannii by limiting nutrient availability.
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Affiliation(s)
- Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer 305817, India.
| | - Moganty R Rajeswari
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
| | - Monalisa Tiwari
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer 305817, India
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Saha P, Xiao X, Yeoh BS, Chen Q, Katkere B, Kirimanjeswara GS, Vijay-Kumar M. The bacterial siderophore enterobactin confers survival advantage to Salmonella in macrophages. Gut Microbes 2018; 10:412-423. [PMID: 30449241 PMCID: PMC6546333 DOI: 10.1080/19490976.2018.1546519] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/31/2018] [Accepted: 10/30/2018] [Indexed: 02/03/2023] Open
Abstract
Enterobactin (Ent), a prototypical bacterial siderophore known for its unparalleled affinity for iron, is widely conserved among members of the Enterobacteriaceae family of Gram-negative bacteria. In this study, we demonstrated that, aside from mediating iron acquisition, Ent also dampened the macrophages (MΦs) antimicrobial responses against intracellular infection by Salmonella enterica serovar Typhimurium. Accordingly, the loss of Ent expression (ΔentB) in Salmonella demoted their survivability against MΦs. Addition of exogenous Ent not only rescued the survival of ΔentB Salmonella, but also augmented WT Salmonella to better withstand the microbicidal activity of MΦs. The protection conferred to WT Salmonella was observed only when Ent was administered as iron-free, thus indicating the requirement of iron chelation in this context. In contrast, the exogenous iron-bound Ent retained its ability to promote the survival of ΔentB Salmonella, albeit modestly. Assessment on MΦs labile iron pool (LIP) revealed that iron-free Ent is able to permeate into MΦs, chelate the intracellular LIP, and regulate the expression of several key iron-regulatory proteins, i.e., divalent metal transporter 1, ferroportin, and hepcidin. Chelation of iron by Ent was also observed to promote the MΦs towards M2 polarization. Collectively, our findings demonstrated that Ent not only facilitates bacterial iron uptake but also disrupts MΦs iron homeostasis and M1/M2 polarization to safeguard intracellular bacteria against the anti-bacterial effects of their host.
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Affiliation(s)
- Piu Saha
- Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Xia Xiao
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Beng San Yeoh
- Graduate Program in Immunology & Infectious Disease, Pennsylvania State University, University Park, PA, USA
| | - Qiuyan Chen
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Bhuvana Katkere
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
| | | | - Matam Vijay-Kumar
- Department of Physiology & Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
- Department of Medical Microbiology & Immunology, University of Toledo, Toledo, OH, USA
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23
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Pérard J, Nader S, Levert M, Arnaud L, Carpentier P, Siebert C, Blanquet F, Cavazza C, Renesto P, Schneider D, Maurin M, Coves J, Crouzy S, Michaud-Soret I. Structural and functional studies of the metalloregulator Fur identify a promoter-binding mechanism and its role in Francisella tularensis virulence. Commun Biol 2018; 1:93. [PMID: 30271974 PMCID: PMC6123631 DOI: 10.1038/s42003-018-0095-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/14/2018] [Indexed: 11/18/2022] Open
Abstract
Francisella tularensis is a Gram-negative bacterium causing tularaemia. Classified as possible bioterrorism agent, it may be transmitted to humans via animal infection or inhalation leading to severe pneumonia. Its virulence is related to iron homeostasis involving siderophore biosynthesis directly controlled at the transcription level by the ferric uptake regulator Fur, as presented here together with the first crystal structure of the tetrameric F. tularensis Fur in the presence of its physiological cofactor, Fe2+. Through structural, biophysical, biochemical and modelling studies, we show that promoter sequences of F. tularensis containing Fur boxes enable this tetrameric protein to bind them by splitting it into two dimers. Furthermore, the critical role of F. tularensis Fur in virulence and pathogenesis is demonstrated with a fur-deleted mutant showing an attenuated virulence in macrophage-like cells and mice. Together, our study suggests that Fur is an attractive target of new antibiotics that attenuate the virulence of F. tularensis. Pérard et al. report the structure of Francisella tularensis Fur (FtFur) with its physiological cofactor Fe2+, and show that FtFur is important for virulence. This study identifies a promoter-driven tetramer splitting mechanism that may provide insight into future antibiotics development.
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Affiliation(s)
- J Pérard
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France.
| | - S Nader
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France
| | - M Levert
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - L Arnaud
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France
| | - P Carpentier
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France
| | - C Siebert
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - F Blanquet
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - C Cavazza
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France
| | - P Renesto
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - D Schneider
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - M Maurin
- Univ. Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, 38000, Grenoble, France
| | - J Coves
- Univ. Grenoble Alpes, CNRS, CEA, IBS, 38000, Grenoble, France
| | - S Crouzy
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France.
| | - I Michaud-Soret
- Univ. Grenoble Alpes, CNRS, CEA, BIG-LCBM, 38000, Grenoble, France.
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Fletcher JR, Crane DD, Wehrly TD, Martens CA, Bosio CM, Jones BD. The Ability to Acquire Iron Is Inversely Related to Virulence and the Protective Efficacy of Francisella tularensis Live Vaccine Strain. Front Microbiol 2018; 9:607. [PMID: 29670588 PMCID: PMC5893802 DOI: 10.3389/fmicb.2018.00607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/15/2018] [Indexed: 02/02/2023] Open
Abstract
Francisella tularensis is a highly infectious bacterial pathogen that causes the potentially fatal disease tularemia. The Live Vaccine Strain (LVS) of F. tularensis subsp. holarctica, while no longer licensed as a vaccine, is used as a model organism for identifying correlates of immunity and bacterial factors that mediate a productive immune response against F. tularensis. Recently, it was reported that two biovars of LVS differed in their virulence and vaccine efficacy. Genetic analysis showed that they differ in ferrous iron homeostasis; lower Fe2+ levels contributed to increased resistance to hydrogen peroxide in the vaccine efficacious LVS biovar. This also correlated with resistance to the bactericidal activity of interferon γ-stimulated murine bone marrow-derived macrophages. We have extended these findings further by showing that a mutant lacking bacterioferritin stimulates poor protection against Schu S4 challenge in a mouse model of tularemia. Together these results suggest that the efficacious biovar of LVS stimulates productive immunity by a mechanism that is dependent on its ability to limit the toxic effects of oxidative stress by maintaining optimally low levels of intracellular Fe2+.
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Affiliation(s)
- Joshua R. Fletcher
- Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States
| | - Deborah D. Crane
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Hamilton, MT, United States
| | - Tara D. Wehrly
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Hamilton, MT, United States
| | - Craig A. Martens
- Genomics Core, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Hamilton, MT, United States
| | - Catharine M. Bosio
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Hamilton, MT, United States
| | - Bradley D. Jones
- Graduate Program in Genetics, University of Iowa, Iowa City, IA, United States
- Department of Microbiology, University of Iowa, Iowa City, IA, United States
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Genomewide Transcriptional Responses of Iron-Starved Chlamydia trachomatis Reveal Prioritization of Metabolic Precursor Synthesis over Protein Translation. mSystems 2018; 3:mSystems00184-17. [PMID: 29468197 PMCID: PMC5811630 DOI: 10.1128/msystems.00184-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/18/2018] [Indexed: 12/16/2022] Open
Abstract
By utilizing an experimental approach that monitors the immediate global response of Chlamydia trachomatis to iron starvation, clues to long-standing issues in Chlamydia biology are revealed, including how Chlamydia adapts to this stress. We determined that this pathogen initiates a transcriptional program that prioritizes replenishment of nutrient stores over replication, possibly in preparation for rapid growth once optimal iron levels are restored. Transcription of genes for biosynthesis of metabolic precursors was generally upregulated, while those involved in multiple steps of translation were downregulated. We also observed an increase in transcription of genes involved in DNA repair and neutralizing oxidative stress, indicating that Chlamydia employs an “all-or-nothing” strategy. Its small genome limits its ability to tailor a specific response to a particular stress. Therefore, the “all-or-nothing” strategy may be the most efficient way of surviving within the host, where the pathogen likely encounters multiple simultaneous immunological and nutritional insults. Iron is essential for growth and development of Chlamydia. Its long-term starvation in cultured mammalian cells leads to production of aberrant noninfectious chlamydial forms, also known as persistence. Immediate transcriptional responses to iron limitation have not been characterized, leaving a knowledge gap of how Chlamydia regulates its response to changes in iron availability. We used the fast-chelating agent 2,2′-bipyridyl (BPDL) to homogeneously starve Chlamydia trachomatis serovar L2 of iron, starting at 6 or 12 h postinfection. Immediate transcriptional responses were monitored after only 3 or 6 h of BPDL treatment, well before formation of aberrant Chlamydia. The first genomewide transcriptional response of C. trachomatis to iron starvation was subsequently determined utilizing RNA sequencing. Only 7% and 8% of the genome were differentially expressed in response to iron starvation at the early and middle stages of development, respectively. Biological pathway analysis revealed an overarching theme. Synthesis of macromolecular precursors (deoxynucleotides, amino acids, charged tRNAs, and acetyl coenzyme A [acetyl-CoA]) was upregulated, while energy-expensive processes (ABC transport and translation) were downregulated. A large fraction of differentially downregulated genes are involved in translation, including those encoding ribosome assembly and initiation and termination factors, which could be analogous to the translation downregulation triggered by stress in other prokaryotes during stringent responses. Additionally, transcriptional upregulation of DNA repair, oxidative stress, and tryptophan salvage genes reveals a possible coordination of responses to multiple antimicrobial and immunological insults. These responses of replicative-phase Chlamydia to iron starvation indicate a prioritization of survival over replication, enabling the pathogen to “stock the pantry” with ingredients needed for rapid growth once optimal iron levels are restored. IMPORTANCE By utilizing an experimental approach that monitors the immediate global response of Chlamydia trachomatis to iron starvation, clues to long-standing issues in Chlamydia biology are revealed, including how Chlamydia adapts to this stress. We determined that this pathogen initiates a transcriptional program that prioritizes replenishment of nutrient stores over replication, possibly in preparation for rapid growth once optimal iron levels are restored. Transcription of genes for biosynthesis of metabolic precursors was generally upregulated, while those involved in multiple steps of translation were downregulated. We also observed an increase in transcription of genes involved in DNA repair and neutralizing oxidative stress, indicating that Chlamydia employs an “all-or-nothing” strategy. Its small genome limits its ability to tailor a specific response to a particular stress. Therefore, the “all-or-nothing” strategy may be the most efficient way of surviving within the host, where the pathogen likely encounters multiple simultaneous immunological and nutritional insults.
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Schmidt IHE, Gildhorn C, Böning MAL, Kulow VA, Steinmetz I, Bast A. Burkholderia pseudomallei modulates host iron homeostasis to facilitate iron availability and intracellular survival. PLoS Negl Trop Dis 2018; 12:e0006096. [PMID: 29329289 PMCID: PMC5785036 DOI: 10.1371/journal.pntd.0006096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 01/25/2018] [Accepted: 11/04/2017] [Indexed: 02/07/2023] Open
Abstract
Background The control over iron homeostasis is critical in host-pathogen-interaction. Iron plays not only multiple roles for bacterial growth and pathogenicity, but also for modulation of innate immune responses. Hepcidin is a key regulator of host iron metabolism triggering degradation of the iron exporter ferroportin. Although iron overload in humans is known to increase susceptibility to Burkholderia pseudomallei, it is unclear how the pathogen competes with the host for the metal during infection. This study aimed to investigate whether B. pseudomallei, the causative agent of melioidosis, modulates iron balance and how regulation of host cell iron content affects intracellular bacterial proliferation. Principal findings Upon infection of primary macrophages with B. pseudomallei, expression of ferroportin was downregulated resulting in higher iron availability within macrophages. Exogenous modification of iron export function by hepcidin or iron supplementation by ferric ammonium citrate led to increased intracellular iron pool stimulating B. pseudomallei growth, whereas the iron chelator deferoxamine reduced bacterial survival. Iron-loaded macrophages exhibited a lower expression of NADPH oxidase, iNOS, lipocalin 2, cytokines and activation of caspase-1. Infection of mice with the pathogen caused a diminished hepatic ferroportin expression, higher iron retention in the liver and lower iron levels in the serum (hypoferremia). In vivo administration of ferric ammonium citrate tended to promote the bacterial growth and inflammatory response, whereas limitation of iron availability significantly ameliorated bacterial clearance, attenuated serum cytokine levels and improved survival of infected mice. Conclusions Our data indicate that modulation of the cellular iron balance is likely to be a strategy of B. pseudomallei to improve iron acquisition and to restrict antibacterial immune effector mechanisms and thereby to promote its intracellular growth. Moreover, we provide evidence that changes in host iron homeostasis can influence susceptibility to melioidosis, and suggest that iron chelating drugs might be an additional therapeutic option. Iron is an essential nutrient for many bacterial pathogens. A sufficient availability is linked to bacterial proliferation and pathogenicity. The host requires iron for cellular functions including innate immune defense mechanisms. Consequently, the control over iron homeostasis plays an important role in the course of infection. Burkholderia pseudomallei is an environmental bacterium ubiquitous in soil and water surfaces causing the disease melioidosis with a wide range of signs and symptoms including localized, pulmonary, or bloodstream infections. Conditions with increased iron stores, such as thalassemia, are considered to increase the risk to acquire melioidosis. Here we show that infection with the pathogen triggers downregulation of the major cellular iron exporter inducing intracellular iron retention and stimulation of bacterial proliferation. Experimental iron overload appears to predispose to infection with B. pseudomallei, whereas iron deficiency confers relative resistance to melioidosis. These effects of changed iron metabolism on the course of infection may be ascribed to modifications in the host immune response and direct effects on bacterial growth, respectively. Thus, the B. pseudomallei-driven alteration of cellular iron traffic leading to increased iron availability can promote its intracellular growth, and treatment with iron chelators together with antibiotics might be an appropriate strategy to control infection.
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Affiliation(s)
- Imke H. E. Schmidt
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Claudia Gildhorn
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Martha A. L. Böning
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Vera A. Kulow
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Ivo Steinmetz
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
- Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Antje Bast
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
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Ramakrishnan G. Iron and Virulence in Francisella tularensis. Front Cell Infect Microbiol 2017; 7:107. [PMID: 28421167 PMCID: PMC5378763 DOI: 10.3389/fcimb.2017.00107] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/16/2017] [Indexed: 12/12/2022] Open
Abstract
Francisella tularensis, the causative agent of tularemia, is a Gram-negative bacterium that infects a variety of cell types including macrophages, and propagates with great efficiency in the cytoplasm. Iron, essential for key enzymatic and redox reactions, is among the nutrients required to support this pathogenic lifestyle and the bacterium relies on specialized mechanisms to acquire iron within the host environment. Two distinct pathways for iron acquisition are encoded by the F. tularensis genome- a siderophore-dependent ferric iron uptake system and a ferrous iron transport system. Genes of the Fur-regulated fslABCDEF operon direct the production and transport of the siderophore rhizoferrin. Siderophore biosynthesis involves enzymes FslA and FslC, while export across the inner membrane is mediated by FslB. Uptake of the rhizoferrin- ferric iron complex is effected by the siderophore receptor FslE in the outer membrane in a TonB-independent process, and FslD is responsible for uptake across the inner membrane. Ferrous iron uptake relies largely on high affinity transport by FupA in the outer membrane, while the Fur-regulated FeoB protein mediates transport across the inner membrane. FslE and FupA are paralogous proteins, sharing sequence similarity and possibly sharing structural features as well. This review summarizes current knowledge of iron acquisition in this organism and the critical role of these uptake systems in bacterial pathogenicity.
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Affiliation(s)
- Girija Ramakrishnan
- Department of Medicine/Division of Infectious Diseases, University of VirginiaCharlottesville, VA, USA
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28
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Owusu-Boaitey N, Bauckman KA, Zhang T, Mysorekar IU. Macrophagic control of the response to uropathogenic E. coli infection by regulation of iron retention in an IL-6-dependent manner. IMMUNITY INFLAMMATION AND DISEASE 2016; 4:413-426. [PMID: 27980776 PMCID: PMC5134725 DOI: 10.1002/iid3.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 12/16/2022]
Abstract
Introduction Uropathogenic Escherichia coli (UPEC), the causative agent of over 85% of urinary tract infections (UTIs), elaborate a number of siderophores to chelate iron from the host. On the other hand, the host immune imperative is to limit the availability of iron to the bacteria. Little is known regarding the mechanisms underlying this host‐iron‐UPEC interaction. Our objective was to determine whether macrophages, in response to UPEC infection, retain extracellular siderophore‐bound and free iron, thus limiting the ability of UPEC to access iron. Methods Quantitative PCR, immunoblotting analysis, and gene expression analysis of wild type and IL‐6‐deficient macrophages was performed. Results We found that (1) macrophages upon UPEC infection increased expression of lipocalin 2, a siderophore‐binding molecule, of Dmt1, a molecule that facilitates macrophage uptake of free iron, and of the intracellular iron cargo molecule ferritin, and decreased expression of the iron exporter ferroportin; (2) bladder macrophages regulate expression of genes involved in iron retention upon UPEC infection; (3) IL‐6, a cytokine known to play an important role in regulating host iron homeostasis as well as host defense to UPEC, regulates this process, in part by promoting production of lipocalin 2; and finally, (4) inhibition of IL‐6 signaling genetically and by neutralizing antibodies against the IL‐6 receptor, promoted intra‐macrophagic UPEC growth in the presence of excess iron. Conclusions Together, our study suggests that macrophages retain siderophore‐bound and free iron in response to UPEC and IL‐6 signaling is necessary for macrophages to limit the growth of UPEC in the presence of excess iron. IL‐6 signaling and iron regulation is one mechanism by which macrophages may mediate UPEC clearance.
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Affiliation(s)
- Nana Owusu-Boaitey
- Department of Obstetrics and Gynecology Washington University School of Medicine St. Louis Missouri
| | - Kyle A Bauckman
- Department of Obstetrics and Gynecology Washington University School of Medicine St. Louis Missouri
| | - Tingxuan Zhang
- Department of Obstetrics and Gynecology Washington University School of Medicine St. Louis Missouri
| | - Indira U Mysorekar
- Department of Obstetrics and GynecologyWashington University School of MedicineSt. LouisMissouri; Department of Pathology and ImmunologyWashington University School of MedicineSt. LouisMissouri
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29
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Kilroy S, Raspoet R, Haesebrouck F, Ducatelle R, Van Immerseel F. Prevention of egg contamination by Salmonella Enteritidis after oral vaccination of laying hens with Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC mutants. Vet Res 2016; 47:82. [PMID: 27519174 PMCID: PMC4982998 DOI: 10.1186/s13567-016-0369-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/01/2016] [Indexed: 11/25/2022] Open
Abstract
Vaccination of laying hens has been successfully used to reduce egg contamination by Salmonella Enteritidis, decreasing human salmonellosis cases worldwide. Currently used vaccines for layers are either inactivated vaccines or live attenuated strains produced by mutagenesis. Targeted gene deletion mutants hold promise for future vaccines, because specific bacterial functions can be removed that may improve safety and allow differentiation from field strains. In this study, the efficacy of Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains in laying hens as live vaccines was evaluated. The mutants are deficient in either the membrane channel TolC (ΔtolC) or the multi-drug efflux systems acrAB, acrEF and mdtABC (ΔacrABacrEFmdtABC). These strains have a decreased ability for gut and tissue colonization and are unable to survive in egg white, the latter preventing transmission of the vaccine strains to humans. Two groups of 30 laying hens were orally inoculated at day 1, 6 weeks and 16 weeks of age with 108 cfu of either vaccine strain, while a third group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 5 × 107 cfu Salmonella Enteritidis PT4 S1400/94. The vaccine strains were not shed or detected in the gut, internal organs or eggs, 2 weeks after the third vaccination. The strains significantly protected against gut and internal organ colonization, and completely prevented egg contamination by Salmonella Enteritidis under the conditions of this study. This indicates that Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains might be valuable strains for vaccination of layers against Salmonella Enteritidis.
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Affiliation(s)
- Sofie Kilroy
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
| | - Ruth Raspoet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Richard Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Filip Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
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30
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Backe MB, Moen IW, Ellervik C, Hansen JB, Mandrup-Poulsen T. Iron Regulation of Pancreatic Beta-Cell Functions and Oxidative Stress. Annu Rev Nutr 2016; 36:241-73. [PMID: 27146016 DOI: 10.1146/annurev-nutr-071715-050939] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary advice is the cornerstone in first-line treatment of metabolic diseases. Nutritional interventions directed at these clinical conditions mainly aim to (a) improve insulin resistance by reducing energy-dense macronutrient intake to obtain weight loss and (b) reduce fluctuations in insulin secretion through avoidance of rapidly absorbable carbohydrates. However, even in the majority of motivated patients selected for clinical trials, massive efforts using this approach have failed to achieve lasting efficacy. Less attention has been given to the role of micronutrients in metabolic diseases. Here, we review the evidence that highlights (a) the importance of iron in pancreatic beta-cell function and dysfunction in diabetes and (b) the integrative pathophysiological effects of tissue iron levels in the interactions among the beta cell, gut microbiome, hypothalamus, innate and adaptive immune systems, and insulin-sensitive tissues. We propose that clinical trials are warranted to clarify the impact of dietary or pharmacological iron reduction on the development of metabolic disorders.
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Affiliation(s)
- Marie Balslev Backe
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark;
| | - Ingrid Wahl Moen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark;
| | - Christina Ellervik
- Department of Laboratory Medicine, Boston Children's Hospital, Boston, Massachusetts 02115
| | - Jakob Bondo Hansen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark;
| | - Thomas Mandrup-Poulsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark;
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31
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Sikkeland J, Sheng X, Jin Y, Saatcioglu F. STAMPing at the crossroads of normal physiology and disease states. Mol Cell Endocrinol 2016; 425:26-36. [PMID: 26911931 DOI: 10.1016/j.mce.2016.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/11/2016] [Accepted: 02/14/2016] [Indexed: 10/24/2022]
Abstract
The six transmembrane protein of prostate (STAMP) proteins, also known as six transmembrane epithelial antigen of prostate (STEAPs), comprises three members: STAMP1-3. Their expression is regulated by a variety of stimuli, including hormones and cytokines, in varied settings and tissues with important roles in secretion and cell differentiation. In addition, they are implicated in metabolic and inflammatory diseases and cancer. Here, we review the current knowledge on the role of STAMPs in both physiological and pathological states.
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Affiliation(s)
| | - Xia Sheng
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Yang Jin
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Fahri Saatcioglu
- Department of Biosciences, University of Oslo, Oslo, Norway; Institute for Cancer Genetics and Informatics, Oslo University Hospital, Oslo, Norway.
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Abstract
Ancient bacteria originated from metal-rich environments. Billions of years of evolution directed these tiny single cell creatures to exploit the versatile properties of metals in catalyzing chemical reactions and biological responses. The result is an entire metallome of proteins that use metal co-factors to facilitate key cellular process that range from the production of energy to the replication of DNA. Two key metals in this regard are iron and zinc, both abundant on Earth but not readily accessible in a human host. Instead, pathogenic bacteria must employ clever ways to acquire these metals. In this review we describe the many elegant ways these bacteria mine, regulate, and craft the use of two key metals (iron and zinc) to build a virulence arsenal that challenges even the most sophisticated immune response.
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Affiliation(s)
- Li Ma
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77459, USA.
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33
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Afonso-Grunz F. Putative alternative polyadenylation (APA) events in the early interaction of Salmonella enterica Typhimurium and human host cells. GENOMICS DATA 2015; 6:222-7. [PMID: 26697380 PMCID: PMC4664775 DOI: 10.1016/j.gdata.2015.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 10/01/2015] [Accepted: 10/02/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Fabian Afonso-Grunz
- Goethe University Frankfurt am Main, Institute for Molecular BioSciences, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.Goethe University Frankfurt am MainInstitute for Molecular BioSciencesMax-von-Laue-Str. 9Frankfurt am Main60438Germany.
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34
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Jamshidi N, Raghunathan A. Cell scale host-pathogen modeling: another branch in the evolution of constraint-based methods. Front Microbiol 2015; 6:1032. [PMID: 26500611 PMCID: PMC4594423 DOI: 10.3389/fmicb.2015.01032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 09/11/2015] [Indexed: 12/12/2022] Open
Abstract
Constraint-based models have become popular methods for systems biology as they enable the integration of complex, disparate datasets in a biologically cohesive framework that also supports the description of biological processes in terms of basic physicochemical constraints and relationships. The scope, scale, and application of genome scale models have grown from single cell bacteria to multi-cellular interaction modeling; host-pathogen modeling represents one of these examples at the current horizon of constraint-based methods. There are now a small number of examples of host-pathogen constraint-based models in the literature, however there has not yet been a definitive description of the methodology required for the functional integration of genome scale models in order to generate simulation capable host-pathogen models. Herein we outline a systematic procedure to produce functional host-pathogen models, highlighting steps which require debugging and iterative revisions in order to successfully build a functional model. The construction of such models will enable the exploration of host-pathogen interactions by leveraging the growing wealth of omic data in order to better understand mechanism of infection and identify novel therapeutic strategies.
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Affiliation(s)
- Neema Jamshidi
- Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA, USA ; Department of Radiological Sciences, University of California, Los Angeles Los Angeles, CA, USA
| | - Anu Raghunathan
- Chemical Engineering Division, National Chemical Laboratory Pune, India
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Burkholderia Diffusible Signal Factor Signals to Francisella novicida To Disperse Biofilm and Increase Siderophore Production. Appl Environ Microbiol 2015; 81:7057-66. [PMID: 26231649 DOI: 10.1128/aem.02165-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/26/2015] [Indexed: 11/20/2022] Open
Abstract
In many bacteria, the ability to modulate biofilm production relies on specific signaling molecules that are either self-produced or made by neighboring microbes within the ecological niche. We analyzed the potential interspecies signaling effect of the Burkholderia diffusible signal factor (BDSF) on Francisella novicida, a model organism for Francisella tularensis, and demonstrated that BDSF both inhibits the formation and causes the dispersion of Francisella biofilm. Specificity was demonstrated for the cis versus the trans form of BDSF. Using transcriptome sequencing, quantitative reverse transcription-PCR, and activity assays, we found that BDSF altered the expression of many F. novicida genes, including genes involved in biofilm formation, such as chitinases. Using a chitinase inhibitor, the antibiofilm activity of BDSF was also shown to be chitinase dependent. In addition, BDSF caused an increase in RelA expression and increased levels of (p)ppGpp, leading to decreased biofilm production. These results support our observation that exposure of F. novicida to BDSF causes biofilm dispersal. Furthermore, BDSF upregulated the genes involved in iron acquisition (figABCD), increasing siderophore production. Thus, this study provides evidence for a potential role and mechanism of diffusible signal factor (DSF) signaling in the genus Francisella and suggests the possibility of interspecies signaling between Francisella and other bacteria. Overall, this study suggests that in response to the interspecies DSF signal, F. novicida can alter its gene expression and regulate its biofilm formation.
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36
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Strategies of Intracellular Pathogens for Obtaining Iron from the Environment. BIOMED RESEARCH INTERNATIONAL 2015; 2015:476534. [PMID: 26120582 PMCID: PMC4450229 DOI: 10.1155/2015/476534] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/09/2015] [Indexed: 12/22/2022]
Abstract
Most microorganisms are destroyed by the host tissues through processes that usually involve phagocytosis and lysosomal disruption. However, some organisms, called intracellular pathogens, are capable of avoiding destruction by growing inside macrophages or other cells. During infection with intracellular pathogenic microorganisms, the element iron is required by both the host cell and the pathogen that inhabits the host cell. This minireview focuses on how intracellular pathogens use multiple strategies to obtain nutritional iron from the intracellular environment in order to use this element for replication. Additionally, the implications of these mechanisms for iron acquisition in the pathogen-host relationship are discussed.
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Barel M, Ramond E, Gesbert G, Charbit A. The complex amino acid diet of Francisella in infected macrophages. Front Cell Infect Microbiol 2015; 5:9. [PMID: 25705612 PMCID: PMC4319460 DOI: 10.3389/fcimb.2015.00009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/14/2015] [Indexed: 12/16/2022] Open
Abstract
Francisella tularensis, the agent of the zoonotic disease tularemia, is a highly infectious bacterium for a large number of animal species and can be transmitted to humans by various means. The bacterium is able to infect a variety of cell types but replicates in mammalian hosts mainly in the cytosol of infected macrophages. In order to resist the stressful and nutrient-restricted intracellular environments, it encounters during its systemic dissemination, Francisella has developed dedicated stress resistance mechanisms and adapted its metabolic and nutritional needs. Recent data form our laboratory and from several other groups have shown that Francisella simultaneously relies on multiple host amino acid sources during its intracellular life cycle. This review will summarize how intracellular Francisella use different amino acid sources, and their role in phagosomal escape and/or cytosolic multiplication and systemic dissemination. We will first summarize the data that we have obtained on two amino acid transporters involved in Francisella phagosomal escape and cytosolic multiplication i.e., the glutamate transporter GadC and the asparagine transporter AnsP, respectively. The specific contribution of glutamate and asparagine to the physiology of the bacterium will be evoked. Then, we will discuss how Francisella has adapted to obtain and utilize host amino acid resources, and notably the contribution of host transporters and autophagy process in the establishment of a nutrient-replete intracellular niche.
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Affiliation(s)
- Monique Barel
- Université Paris Descartes, Sorbonne Paris Cité Paris, France ; INSERM U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades Paris, France
| | - Elodie Ramond
- Université Paris Descartes, Sorbonne Paris Cité Paris, France ; INSERM U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades Paris, France
| | - Gael Gesbert
- Université Paris Descartes, Sorbonne Paris Cité Paris, France ; INSERM U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades Paris, France
| | - Alain Charbit
- Université Paris Descartes, Sorbonne Paris Cité Paris, France ; INSERM U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades Paris, France
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38
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Inflammation and ER stress downregulate BDH2 expression and dysregulate intracellular iron in macrophages. J Immunol Res 2014; 2014:140728. [PMID: 25762501 PMCID: PMC4267003 DOI: 10.1155/2014/140728] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022] Open
Abstract
Macrophages play a very important role in host defense and in iron homeostasis by engulfing senescent red blood cells and recycling iron. Hepcidin is the master iron regulating hormone that limits dietary iron absorption from the gut and limits iron egress from macrophages. Upon infection macrophages retain iron to limit its bioavailability which limits bacterial growth. Recently, a short chain butyrate dehydrogenase type 2 (BDH2) protein was reported to contain an iron responsive element and to mediate cellular iron trafficking by catalyzing the synthesis of the mammalian siderophore that binds labile iron; therefore, BDH2 plays a crucial role in intracellular iron homeostasis. However, BDH2 expression and regulation in macrophages have not yet been described. Here we show that LPS-induced inflammation combined with ER stress led to massive BDH2 downregulation, increased the expression of ER stress markers, upregulated hepcidin expression, downregulated ferroportin expression, caused iron retention in macrophages, and dysregulated cytokine release from macrophages. We also show that ER stress combined with inflammation synergistically upregulated the expression of the iron carrier protein NGAL and the stress-inducible heme degrading enzyme heme oxygenase-1 (HO-1) leading to iron liberation. This is the first report to show that inflammation and ER stress downregulate the expression of BDH2 in human THP-1 macrophages.
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39
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Steiner DJ, Furuya Y, Metzger DW. Host-pathogen interactions and immune evasion strategies in Francisella tularensis pathogenicity. Infect Drug Resist 2014; 7:239-51. [PMID: 25258544 PMCID: PMC4173753 DOI: 10.2147/idr.s53700] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Francisella tularensis is an intracellular Gram-negative bacterium that causes life-threatening tularemia. Although the prevalence of natural infection is low, F. tularensis remains a tier I priority pathogen due to its extreme virulence and ease of aerosol dissemination. F. tularensis can infect a host through multiple routes, including the intradermal and respiratory routes. Respiratory infection can result from a very small inoculum (ten organisms or fewer) and is the most lethal form of infection. Following infection, F. tularensis employs strategies for immune evasion that delay the immune response, permitting systemic distribution and induction of sepsis. In this review we summarize the current knowledge of F. tularensis in an immunological context, with emphasis on the host response and bacterial evasion of that response.
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Affiliation(s)
- Don J Steiner
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
| | - Yoichi Furuya
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
| | - Dennis W Metzger
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
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40
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Tam JCH, Jacques DA. Intracellular immunity: finding the enemy within--how cells recognize and respond to intracellular pathogens. J Leukoc Biol 2014; 96:233-44. [PMID: 24899588 PMCID: PMC4192899 DOI: 10.1189/jlb.4ri0214-090r] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/06/2014] [Accepted: 05/10/2014] [Indexed: 12/24/2022] Open
Abstract
Historically, once a cell became infected, it was considered to be beyond all help. By this stage, the invading pathogen had breached the innate defenses and was beyond the reach of the humoral arm of the adaptive immune response. The pathogen could still be removed by cell-mediated immunity (e.g., by NK cells or cytotoxic T lymphocytes), but these mechanisms necessitated the destruction of the infected cell. However, in recent years, it has become increasingly clear that many cells possess sensor and effector mechanisms for dealing with intracellular pathogens. Most of these mechanisms are not restricted to professional immune cells nor do they all necessitate the destruction of the host. In this review, we examine the strategies that cells use to detect and destroy pathogens once the cell membrane has been penetrated.
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Affiliation(s)
- Jerry C H Tam
- Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - David A Jacques
- Medical Research Council Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
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41
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Pérez NM, Ramakrishnan G. The reduced genome of the Francisella tularensis live vaccine strain (LVS) encodes two iron acquisition systems essential for optimal growth and virulence. PLoS One 2014; 9:e93558. [PMID: 24695402 PMCID: PMC3973589 DOI: 10.1371/journal.pone.0093558] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/07/2014] [Indexed: 01/19/2023] Open
Abstract
Bacterial pathogens require multiple iron-specific acquisition systems for survival within the iron-limiting environment of the host. Francisella tularensis is a virulent intracellular pathogen that can replicate in multiple cell-types. To study the interrelationship of iron acquisition capability and virulence potential of this organism, we generated single and double deletion mutants within the ferrous iron (feo) and ferric-siderophore (fsl) uptake systems of the live vaccine strain (LVS). The Feo system was disrupted by a partial deletion of the feoB gene (ΔfeoB′), which led to a growth defect on iron-limited modified Muller Hinton agar plates. 55Fe uptake assays verified that the ΔfeoB′ mutant had lost the capacity for ferrous iron uptake but was still competent for 55Fe-siderophore-mediated ferric iron acquisition. Neither the ΔfeoB′ nor the siderophore-deficient ΔfslA mutant was defective for replication within J774A.1 murine macrophage-like cells, thus demonstrating the ability of LVS to survive using either ferrous or ferric sources of intracellular iron. A LVS ΔfslA ΔfeoB′ mutant defective for both ferrous iron uptake and siderophore production was isolated in the presence of exogenous F. tularensis siderophore. In contrast to the single deletion mutants, the ΔfslA ΔfeoB′ mutant was unable to replicate within J774A.1 cells and was attenuated in virulence following intraperitoneal infection of C57BL/6 mice. These studies demonstrate that the siderophore and feoB-mediated ferrous uptake systems are the only significant iron acquisition systems in LVS and that they operate independently. While one system can compensate for loss of the other, both are required for optimal growth and virulence.
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Affiliation(s)
- Natalie Marie Pérez
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Girija Ramakrishnan
- Department of Medicine, Division of Infectious Disease and International Health, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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42
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Minandri F, Bonchi C, Frangipani E, Imperi F, Visca P. Promises and failures of gallium as an antibacterial agent. Future Microbiol 2014; 9:379-97. [DOI: 10.2217/fmb.14.3] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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43
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Silva-Gomes S, Bouton C, Silva T, Santambrogio P, Rodrigues P, Appelberg R, Gomes MS. Mycobacterium avium infection induces H-ferritin expression in mouse primary macrophages by activating Toll-like receptor 2. PLoS One 2013; 8:e82874. [PMID: 24349383 PMCID: PMC3857292 DOI: 10.1371/journal.pone.0082874] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 11/06/2013] [Indexed: 11/18/2022] Open
Abstract
Important for both host and pathogen survivals, iron is a key factor in determining the outcome of an infectious process. Iron with-holding, including sequestration inside tissue macrophages, is considered an important strategy to fight infection. However, for intra-macrophagic pathogens, such as Mycobacterium avium, host defence may depend on intracellular iron sequestration mechanisms. Ferritin, the major intracellular iron storage protein, plays a critical role in this process. In the current study, we studied ferritin expression in mouse bone marrow-derived macrophages upon infection with M. avium. We found that H-ferritin is selectively increased in infected macrophages, through an up-regulation of gene transcription. This increase was mediated by the engagement of Toll like receptor-2, and was independent of TNF-alpha or nitric oxide production. The formation of H-rich ferritin proteins and the consequent iron sequestration may be an important part of the panoply of antimicrobial mechanisms of macrophages.
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Affiliation(s)
- Sandro Silva-Gomes
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Cécile Bouton
- Institut de Chimie des Substances Naturelles, UPR2301 CNRS, Centre de Recherche de Gif, Gif-sur-Yvette, France
| | - Tânia Silva
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | | | - Pedro Rodrigues
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Rui Appelberg
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria Salomé Gomes
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- * E-mail:
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44
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Nagy TA, Moreland SM, Andrews-Polymenis H, Detweiler CS. The ferric enterobactin transporter Fep is required for persistent Salmonella enterica serovar typhimurium infection. Infect Immun 2013; 81:4063-70. [PMID: 23959718 PMCID: PMC3811836 DOI: 10.1128/iai.00412-13] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 08/10/2013] [Indexed: 01/24/2023] Open
Abstract
Most bacterial pathogens require iron to grow and colonize host tissues. The Gram-negative bacterium Salmonella enterica serovar Typhimurium causes a natural systemic infection of mice that models acute and chronic human typhoid fever. S. Typhimurium resides in tissues within cells of the monocyte lineage, which limit pathogen access to iron, a mechanism of nutritional immunity. The primary ferric iron import system encoded by Salmonella is the siderophore ABC transporter FepBDGC. The Fep system has a known role in acute infection, but it is unclear whether ferric iron uptake or the ferric iron binding siderophores enterobactin and salmochelin are required for persistent infection. We defined the role of the Fep iron transporter and siderophores in the replication of Salmonella in macrophages and in mice that develop acute followed by persistent infections. Replication of wild-type and iron transporter mutant Salmonella strains was quantified in cultured macrophages, fecal pellets, and host tissues in mixed- and single-infection experiments. We show that deletion of fepB attenuated Salmonella replication and colonization within macrophages and mice. Additionally, the genes required to produce and transport enterobactin and salmochelin across the outer membrane receptors, fepA and iroN, are needed for colonization of all tissues examined. However, salmochelin appears to be more important than enterobactin in the colonization of the spleen and liver, both sites of dissemination. Thus, the FepBDGC ferric iron transporter and the siderophores enterobactin and salmochelin are required by Salmonella to evade nutritional immunity in macrophages and cause persistent infection in mice.
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Affiliation(s)
- Toni A. Nagy
- Department of Molecular, Cellular and Developmental Biology, University of Colorado—Boulder, Boulder, Colorado, USA
| | - Sarah M. Moreland
- Department of Molecular, Cellular and Developmental Biology, University of Colorado—Boulder, Boulder, Colorado, USA
| | | | - Corrella S. Detweiler
- Department of Molecular, Cellular and Developmental Biology, University of Colorado—Boulder, Boulder, Colorado, USA
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45
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Abstract
Francisella tularensis, the bacterial cause of tularemia, infects the liver and replicates in hepatocytes in vivo and in vitro. However, the factors that govern adaptation of F. tularensis to the intrahepatocytic niche have not been identified. Using cDNA microarrays, we determined the transcriptional profile of the live vaccine strain (LVS) of F. tularensis grown in the FL83B murine hepatocytic cell line compared to that of F. tularensis cultured in broth. The fslC gene of the fsl operon was the most highly upregulated. Deletion of fslC eliminated the ability of the LVS to produce siderophore, which is involved in uptake of ferric iron, but it did not impair its growth in hepatocytes, A549 epithelial cells, or macrophages. Therefore, we sought an alternative means by which F. tularensis might obtain iron. Deletion of feoB, which encodes a putative ferrous iron transporter, retarded replication of the LVS in iron-restricted media, reduced its growth in hepatocytic and epithelial cells, and impaired its acquisition of iron. Survival of mice infected intradermally with a lethal dose of the LVS was slightly improved by deletion of fslC but was not altered by loss of feoB. However, the ΔfeoB mutant showed diminished ability to colonize the lungs, liver, and spleen of mice that received sublethal inocula. Thus, FeoB represents a previously unidentified mechanism for uptake of iron by F. tularensis. Moreover, failure to produce a mutant strain lacking both feoB and fslC suggests that FeoB and the proteins of the fsl operon are the only major means by which F. tularensis acquires iron.
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Galliera E, Dozio E, Dogliotti G, Vassena C, Colloredo Mels L, Romano CL, Mattina R, Corsi MM, Drago L. Iron status evaluation as a marker of postoperative joint infection: a pilot study. Int J Immunopathol Pharmacol 2013; 25:1149-55. [PMID: 23298506 DOI: 10.1177/039463201202500433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We evaluated the effect of different inflammatory conditions on iron status and, as a consequence, the possible use of iron markers as indicators of infection in the diagnosis of postoperative prosthetic orthopaedic joint infections. The study population was consisted of 26 patients undergoing revision of total hip or total knee joint arthroplasty and subdivided into three groups according to the cause of prosthesis implant failure: 10 as having had previous infection (Group A), 10 patients were categorized as having infection (Group B); and the remaining 6 (Group C) as not having infection. These patients were assayed for mean corpuscular haemoglobin concentration (MCHC) and serum values of iron (Fe), ferritin (Fer), transferrin (Tf), soluble transferrin receptor (sTfR), and transferrin saturation (sat Tf). Septic patients display statistically significant lower serum iron concentration, higher sTfR and ferritin levels, lower, but not statistically significant, MCHC compared to non septic ones. Little differences were observed for Tf, sat Tf, tibc, TfR index, among the three groups of patients. Our study suggests that iron status parameters, in particular serum iron, ferritin, sTfR and TfR index, could be useful tools for the early detection and the diagnosis of orthopaedic prosthetic joint infections.
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van Santen S, de Mast Q, Swinkels DW, van der Ven AJAM. The iron link between malaria and invasive non-typhoid Salmonella infections. Trends Parasitol 2013; 29:220-7. [PMID: 23601932 DOI: 10.1016/j.pt.2013.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/11/2013] [Accepted: 03/12/2013] [Indexed: 02/06/2023]
Abstract
Epidemiological studies have demonstrated an association between malaria and invasive non-typhoid Salmonella (NTS) infections, especially in children. We explore the role of iron as a possible cofactor in this association. Malarial disease, among others, is associated with enhanced erythrophagocytosis and inflammation, which increases the iron content of macrophages and thereby also the survival of Salmonella spp. within macrophages. Whether iron supplementation programs augment the risk of invasive NTS infections in malaria-endemic regions is an important global health issue that still needs to be determined.
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Affiliation(s)
- Susanne van Santen
- Department of General Internal Medicine, Nijmegen Institute for International Health (456), Radboud University Medical Center, Geert Grooteplein Zuid 8, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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Bellmann-Weiler R, Schroll A, Engl S, Nairz M, Talasz H, Seifert M, Weiss G. Neutrophil gelatinase-associated lipocalin and interleukin-10 regulate intramacrophage Chlamydia pneumoniae replication by modulating intracellular iron homeostasis. Immunobiology 2012; 218:969-78. [PMID: 23317919 PMCID: PMC3657155 DOI: 10.1016/j.imbio.2012.11.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 10/31/2012] [Accepted: 11/13/2012] [Indexed: 12/22/2022]
Abstract
Neutrophil gelatinase-associated lipocalin (NGAL/Lipocalin-2/Lcn-2) is a 25 kDa protein which is involved in host defence against certain Gram negative bacteria upon binding of iron loaded bacterial siderophores thereby limiting the availability of this essential nutrient to bacteria resulting in inhibition of their growth and pathogenicity. As iron is important for the growth of the intracellular bacterium Chlamydia pneumoniae we questioned whether Lcn-2 affects the course of this infection. We employed primary peritoneal macrophages obtained from wildtype and Lcn-2 −/− mice and RAW 264.7 cells which were infected with C. pneumoniae. In addition, we studied C. pneumoniae multiplication in vivo in mice receiving diets with varying iron contents. We analyzed C. pneumoniae numbers by immunohistochemistry and RT-PCR and studied the expression of iron metabolism and cytokine genes by RT-PCR, Western blot or ELISA. Infection with Chlamydiae ex vivo and in vivo revealed a significantly higher bacterial growth in peritoneal macrophages of Lcn-2 −/− than of wildtype mice. These differences were significantly more pronounced upon iron challenge, which stimulated bacterial growth. Accordingly, treatment with an anti-Lnc-2 antibody increased whereas addition of recombinant Lcn-2 reduced bacterial growth in infected macrophages. When investigating the underlying mechanisms we observed partly different expression of several iron metabolism genes between Lcn-2 +/+ and Lcn-2 −/− macrophages and most strikingly an increased formation of the anti-inflammatory cytokine IL-10 by Lcn-2 −/− macrophages. Upon treatment with an anti-IL10 antibody we experienced a significant increase of Chlamydial growth within Lcn-2 −/− macrophages along with a reduction of the major iron storage protein ferritin. Herein we provide first time evidence that Lcn-2 is involved in host defence against Chlamydia presumably by limiting the availability of iron to the pathogen. In the absence of Lcn-2, increased formation of IL-10 exerts protective effects by increasing the intracellular formation of ferritin, thereby reducing the access of iron for bacteria.
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Affiliation(s)
- Rosa Bellmann-Weiler
- Department of Internal Medicine VI, Clinical Immunology and Infectious Diseases, Medical University of Innsbruck, Austria
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Subversion of host recognition and defense systems by Francisella spp. Microbiol Mol Biol Rev 2012; 76:383-404. [PMID: 22688817 DOI: 10.1128/mmbr.05027-11] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Francisella tularensis is a gram-negative intracellular pathogen and the causative agent of the disease tularemia. Inhalation of as few as 10 bacteria is sufficient to cause severe disease, making F. tularensis one of the most highly virulent bacterial pathogens. The initial stage of infection is characterized by the "silent" replication of bacteria in the absence of a significant inflammatory response. Francisella achieves this difficult task using several strategies: (i) strong integrity of the bacterial surface to resist host killing mechanisms and the release of inflammatory bacterial components (pathogen-associated molecular patterns [PAMPs]), (ii) modification of PAMPs to prevent activation of inflammatory pathways, and (iii) active modulation of the host response by escaping the phagosome and directly suppressing inflammatory pathways. We review the specific mechanisms by which Francisella achieves these goals to subvert host defenses and promote pathogenesis, highlighting as-yet-unanswered questions and important areas for future study.
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Grunewald TGP, Bach H, Cossarizza A, Matsumoto I. The STEAP protein family: versatile oxidoreductases and targets for cancer immunotherapy with overlapping and distinct cellular functions. Biol Cell 2012; 104:641-57. [PMID: 22804687 DOI: 10.1111/boc.201200027] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/08/2012] [Indexed: 12/26/2022]
Abstract
The human six-transmembrane epithelial antigen of the prostate (STEAP) protein family contains at least five homologous members. The necessity of multiple homologous STEAP proteins is still unclear, but their peculiar and tissue-specific expression suggests that they are assigned to distinct functional tasks. This concept is supported by the fact that especially STEAP1, and to a lesser extent STEAP2 and -4, are highly over-expressed in many different cancer entities, while being only minimally expressed in a few normal tissues. Despite their very similar domain organisation, STEAP3 seems to act as a potent metalloreductase essential for physiological iron uptake and turnover, while in particular STEAP4 appears to be rather involved in responses to nutrients and inflammatory stress, fatty acid and glucose metabolism. Moreover, individual STEAP proteins possess overlapping functions important for growth and survival of cancer cells. Due to their membrane-bound localisation and their high expression in many different cancers such as prostate, breast and bladder carcinoma as well as Ewing's sarcoma, STEAP proteins have been recognised and utilised as promising targets for cell- and antibody-based immunotherapy. This review summarises our present knowledge of the individual members of the human STEAP family and highlights the functional differences between them.
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Affiliation(s)
- Thomas G P Grunewald
- INSERM Unit 830 'Genetics and Biology of Cancer', Institut Curie Research Center, Paris, France.
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