1
|
Lazado CC, Iversen M, Johansen LH, Brenne H, Sundaram AYM, Ytteborg E. Nasal responses to elevated temperature and Francisella noatunensis infection in Atlantic cod (Gadus morhua). Genomics 2023; 115:110735. [PMID: 37898334 DOI: 10.1016/j.ygeno.2023.110735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/22/2023] [Accepted: 10/25/2023] [Indexed: 10/30/2023]
Abstract
We report the histological and transcriptomic changes in the olfactory organ of Atlantic cod exposed to Francisella noatunensis. Experimental infection was performed at either 12 °C or 17 °C. Infected fish presented the classic gross pathologies of francisellosis. Nasal morpho-phenotypic parameters were not significantly affected by elevated temperature and infection, except for the number of mucus cells in the 12 °C group seven weeks after the challenge. A higher number of genes were altered through time in the group reared at 17 °C. At termination, the nasal transcriptome of infected fish in both groups was similar to the control. When both infected groups were compared, 754 DEGs were identified, many of which were involved in signalling, defence, transmembrane and enzymatic processes. In conclusion, the study reveals that elevated temperature could trigger responses in the olfactory organ of Atlantic cod and shape the nasal response to F. noatunensis infection.
Collapse
Affiliation(s)
- Carlo C Lazado
- Nofima, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås 1431, Norway.
| | - Marianne Iversen
- Nofima, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Tromsø 9019, Norway
| | - Lill-Heidi Johansen
- Nofima, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Tromsø 9019, Norway
| | - Hanne Brenne
- Nofima, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Tromsø 9019, Norway
| | - Arvind Y M Sundaram
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Elisabeth Ytteborg
- Nofima, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås 1431, Norway
| |
Collapse
|
2
|
Rosa CP, Belo TCA, Santos NCDM, Silva EN, Gasparotto J, Corsetti PP, de Almeida LA. Reactive oxygen species trigger inflammasome activation after intracellular microbial interaction. Life Sci 2023; 331:122076. [PMID: 37683723 DOI: 10.1016/j.lfs.2023.122076] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/16/2023] [Accepted: 09/05/2023] [Indexed: 09/10/2023]
Abstract
The intracellular production of reactive oxygen species (ROS), composed of oxygen-reduced molecules, is important not only because of their lethal effects on microorganisms but also due to their potential inflammatory and metabolic regulation properties. The ROS pro-inflammatory properties are associated with the second signal to inflammasome activation, leading to cleaving pro-IL-1β and pro-IL18 before their secretion, as well as gasdermin-D, leading to pyroptosis. Some microorganisms can modulate NLRP3 and AIM-2 inflammasomes through ROS production: whilst Mycobacterium bovis, Mycobacterium kansasii, Francisella novicida, Brucella abortus, Listeria monocytogenes, Influenza virus, Syncytial respiratory virus, Porcine reproductive and respiratory syndrome virus, SARS-CoV, Mayaro virus, Leishmania amazonensis and Plasmodium sp. enhance inflammasome assembly, Hepatitis B virus, Mycobacterium marinum, Mycobacterium tuberculosis, Francisella tularensis and Leishmania sp. disrupt it. This process represents a recent cornerstone in our knowledge of the immunology of intracellular pathogens, which is reviewed in this mini-review.
Collapse
Affiliation(s)
- Caio Pupin Rosa
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Thiago Caetano Andrade Belo
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Natália Cristina de Melo Santos
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Evandro Neves Silva
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Juciano Gasparotto
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Patrícia Paiva Corsetti
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil
| | - Leonardo Augusto de Almeida
- Laboratory of Molecular Biology of Microorganisms, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, Minas Gerais, Brazil.
| |
Collapse
|
3
|
Mehta HH, Song X, Shamoo Y. Intracellular Experimental Evolution of Francisella tularensis Subsp. holarctica Live Vaccine Strain (LVS) to Antimicrobial Resistance. ACS Infect Dis 2023; 9:308-321. [PMID: 36662533 PMCID: PMC9996545 DOI: 10.1021/acsinfecdis.2c00483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In vitro experimental evolution has complemented clinical studies as an excellent tool to identify genetic changes responsible for the de novo evolution of antimicrobial resistance. However, the in vivo context for adaptation contributes to the success of particular evolutionary trajectories, especially in intracellular niches where the adaptive landscape of virulence and resistance are strongly coupled. In this work, we designed an ex vivo evolution approach to identify evolutionary trajectories responsible for antibiotic resistance in the Live Vaccine Strain (LVS) of Francisella tularensis subsp. holarctica while being passaged to increasing ciprofloxacin (CIP) and doxycycline (DOX) concentrations within macrophages. Overall, adaptation within macrophages advanced much slower when compared to previous in vitro evolution studies reflecting a limiting capacity for the expansion of adaptive mutations within the macrophage. Longitudinal genomic analysis identified resistance conferring gyrase mutations outside the Quinolone Resistance Determining Region. Strikingly, FupA/B mutations that are uniquely associated with in vitro CIP resistance in Francisella were not observed ex vivo, reflecting the coupling of intracellular survival and resistance during intracellular adaptation. To our knowledge, this is the first experimental study demonstrating the ability to conduct experimental evolution to antimicrobial resistance within macrophages. The results provide evidence of differences in mutational profiles of populations adapted to the same antibiotic in different environments/cellular compartments and underscore the significance of host mediated stress during resistance evolution.
Collapse
Affiliation(s)
- Heer H Mehta
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
| | - Xinhao Song
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
| | - Yousif Shamoo
- Department of BioSciences, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
4
|
Martínez D, Oyarzún-Salazar R, Quilapi AM, Coronado J, Enriquez R, Vargas-Lagos C, Oliver C, Santibañez N, Godoy M, Muñoz JL, Vargas-Chacoff L, Romero A. Live and inactivated Piscirickettsia salmonis activated nutritional immunity in Atlantic salmon ( Salmo salar). Front Immunol 2023; 14:1187209. [PMID: 37187753 PMCID: PMC10175622 DOI: 10.3389/fimmu.2023.1187209] [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: 03/15/2023] [Accepted: 04/18/2023] [Indexed: 05/17/2023] Open
Abstract
Nutritional immunity regulates the homeostasis of micronutrients such as iron, manganese, and zinc at the systemic and cellular levels, preventing the invading microorganisms from gaining access and thereby limiting their growth. Therefore, the objective of this study was to evaluate the activation of nutritional immunity in specimens of Atlantic salmon (Salmo salar) that are intraperitoneally stimulated with both live and inactivated Piscirickettsia salmonis. The study used liver tissue and blood/plasma samples on days 3, 7, and 14 post-injections (dpi) for the analysis. Genetic material (DNA) of P. salmonis was detected in the liver tissue of fish stimulated with both live and inactivated P. salmonis at 14 dpi. Additionally, the hematocrit percentage decreased at 3 and 7 dpi in fish stimulated with live P. salmonis, unchanged in fish challenged with inactivated P. salmonis. On the other hand, plasma iron content decreased during the experimental course in fish stimulated with both live and inactivated P. salmonis, although this decrease was statistically significant only at 3 dpi. Regarding the immune-nutritional markers such as tfr1, dmt1, and ireg1 were modulated in the two experimental conditions, compared to zip8, ft-h, and hamp, which were down-regulated in fish stimulated with live and inactivated P. salmonis during the course experimental. Finally, the intracellular iron content in the liver increased at 7 and 14 dpi in fish stimulated with live and inactivated P. salmonis, while the zinc content decreased at 14 dpi under both experimental conditions. However, stimulation with live and inactivated P. salmonis did not alter the manganese content in the fish. The results suggest that nutritional immunity does not distinguish between live and inactivated P. salmonis and elicits a similar immune response. Probably, this immune mechanism would be self-activated with the detection of PAMPs, instead of a sequestration and/or competition of micronutrients by the living microorganism.
Collapse
Affiliation(s)
- Danixa Martínez
- Laboratorio Institucional de Investigación, Facultad de Ciencias de la Naturaleza, Universidad San Sebastián, Puerto Montt, Chile
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- *Correspondence: Danixa Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
| | - Ricardo Oyarzún-Salazar
- Laboratorio Institucional de Investigación, Facultad de Ciencias de la Naturaleza, Universidad San Sebastián, Puerto Montt, Chile
| | - Ana María Quilapi
- Escuela de Tecnología Médica, Facultad de la Salud, Universidad Santo Tomás, Osorno, Chile
| | - José Coronado
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Ricardo Enriquez
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Carolina Vargas-Lagos
- Escuela de Tecnología Médica, Facultad de la Salud, Universidad Santo Tomás, Osorno, Chile
| | - Cristian Oliver
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Natacha Santibañez
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Marcos Godoy
- Laboratorio Institucional de Investigación, Facultad de Ciencias de la Naturaleza, Universidad San Sebastián, Puerto Montt, Chile
- Centro de Investigaciones Biológicas Aplicadas (CIBA), Puerto Montt, Chile
| | - José Luis Muñoz
- Centro de Investigación y Desarrollo i~mar, Universidad de los Lagos, Puerto Montt, Chile
| | - Luis Vargas-Chacoff
- 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, Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), University Austral of Chile, Valdivia, Chile
- *Correspondence: Danixa Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
| | - Alex Romero
- Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Centro Fondap Interdisciplinary Center for Aquaculture Research (INCAR), Universidad de Concepción, Concepción, Chile
- *Correspondence: Danixa Martínez, ; Luis Vargas-Chacoff, ; Alex Romero,
| |
Collapse
|
5
|
Nakamura T, Shimizu T, Ikegaya R, Uda A, Watanabe K, Watarai M. Identification of pyrC gene as an immunosuppressive factor in Francisella novicida infection. Front Cell Infect Microbiol 2022; 12:1027424. [DOI: 10.3389/fcimb.2022.1027424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/13/2022] [Indexed: 11/13/2022] Open
Abstract
Francisella tularensis, a bacterial causative agent of the zoonosis tularemia, is highly pathogenic to humans. The pathogenicity of this bacterium is characterized by intracellular growth in immune cells, like macrophages, and host immune suppression. However, the detailed mechanism of immune suppression by F. tularensis is still unclear. To identify the key factors causing Francisella-mediated immunosuppression, large-scale screening using a transposon random mutant library containing 3552 mutant strains of F. tularensis subsp. novicida (F. novicida) was performed. Thirteen mutants that caused stronger tumor necrosis factor (TNF)-α production in infected U937 human macrophage cells than the wild-type F. novicida strain were isolated. Sequencing analysis of transposon insertion sites revealed 10 genes, including six novel genes, as immunosuppressive factors of Francisella. Among these, the relationship of the pyrC gene, which encodes dihydroorotase in the pyrimidine biosynthesis pathway, with Francisella-mediated immunosuppression was investigated. The pyrC deletion mutant strain (ΔpyrC) induced higher TNF-α production in U937 host cells than the wild-type F. novicida strain. The ΔpyrC mutant strain was also found to enhance host interleukin-1β and interferon (IFN)-β production. The heat-inactivated ΔpyrC mutant strain could not induce host TNF-α production. Moreover, the production of IFN-β resulting from ΔpyrC infection in U937 cells was repressed upon treatment with the stimulator of interferon genes (STING)-specific inhibitor, H-151. These results suggest that pyrC is related to the immunosuppressive activity and pathogenicity of Francisella via the STING pathway.
Collapse
|
6
|
Nagaratnam N, Martin-Garcia JM, Yang JH, Goode MR, Ketawala G, Craciunescu FM, Zook JD, Sonowal M, Williams D, Grant TD, Fromme R, Hansen DT, Fromme P. Structural and biophysical properties of FopA, a major outer membrane protein of Francisella tularensis. PLoS One 2022; 17:e0267370. [PMID: 35913965 PMCID: PMC9342783 DOI: 10.1371/journal.pone.0267370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/08/2022] [Indexed: 11/20/2022] Open
Abstract
Francisella tularensis is an extremely infectious pathogen and a category A bioterrorism agent. It causes the highly contagious zoonosis, Tularemia. Currently, FDA approved vaccines against tularemia are unavailable. F. tularensis outer membrane protein A (FopA) is a well-studied virulence determinant and protective antigen against tularemia. It is a major outer membrane protein (Omp) of F. tularensis. However, FopA-based therapeutic intervention is hindered due to lack of complete structural information for membrane localized mature FopA. In our study, we established recombinant expression, monodisperse purification, crystallization and X-ray diffraction (~6.5 Å) of membrane localized mature FopA. Further, we performed bioinformatics and biophysical experiments to unveil its structural organization in the outer membrane. FopA consists of 393 amino acids and has less than 40% sequence identity to known bacterial Omps. Using comprehensive sequence alignments and structure predictions together with existing partial structural information, we propose a two-domain organization for FopA. Circular dichroism spectroscopy and heat modifiability assay confirmed FopA has a β-barrel domain consistent with alphafold2’s prediction of an eight stranded β-barrel at the N-terminus. Small angle X-ray scattering (SAXS) and native-polyacrylamide gel electrophoresis revealed FopA purified in detergent micelles is predominantly dimeric. Molecular density derived from SAXS at 31 Å shows putative dimeric N-terminal β-barrels surrounded by detergent corona and connected to C-terminal domains via flexible linker. Disorder analysis predicts N- and C-terminal domains are interspersed by a long intrinsically disordered region and alphafold2 predicts this region to be largely unstructured. Taken together, we propose a dimeric, two-domain organization of FopA in the outer membrane: the N-terminal β-barrel is membrane embedded, provides dimerization interface and tethers to membrane extrinsic C-terminal domain via long flexible linker. Structure determination of membrane localized mature FopA is essential to understand its role in pathogenesis and develop anti-tularemia therapeutics. Our results pave the way towards it.
Collapse
Affiliation(s)
- Nirupa Nagaratnam
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jose M. Martin-Garcia
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Jay-How Yang
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Matthew R. Goode
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Gihan Ketawala
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Felicia M. Craciunescu
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - James D. Zook
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Manashi Sonowal
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Dewight Williams
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Eyring Materials Center, Arizona State University, Tempe, Arizona, United States of America
| | - Thomas D. Grant
- Department of Structural Biology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, New York, New York, United States of America
| | - Raimund Fromme
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Debra T. Hansen
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- Center for Innovations in Medicine, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
| | - Petra Fromme
- Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| |
Collapse
|
7
|
Díaz-Ibarrola D, Martínez D, Vargas-Lagos C, Saravia J, Vargas-Chacoff L. Transcriptional modulation of immune genes in gut of Sub-Antarctic notothenioid fish Eleginops maclovinus challenged with Francisella noatunensis subsp. noatunensis. FISH & SHELLFISH IMMUNOLOGY 2022; 124:56-65. [PMID: 35367625 DOI: 10.1016/j.fsi.2022.03.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
The search for functional foods that improve the immune response has traditionally been focused on lymphoid tissue and the intestinal mucosa. However, it is unknown whether there is a different immune response in different portions of the gut following exposure to a bacterial pathogen. We challenged Eleginops maclovinus intraperitoneally (i.p) with Francisella noatunensis subsp. noatunensis and measured mRNA transcripts related to innate and adaptive immune responses in different parts of the gut (foregut, midgut and hindgut). We used control (i.p only with bacterial culture medium), low dose (i.p of F. noatunensis at 1 × 101 bact/μL), medium dose (i.p of F. noatunensis at 1 × 105 bact/μL) and high dose (i.p of F. noatunensis at 1 × 1010 bact/μL) groups in our experiments. We sampled fish at days 1, 3, 7, 14, 21, and 28 post-injection. We observed tissue-specific expression of TLR1, TLR5, TLR8, MHCI, MHCII and IgM, and transcription of these immune markers was lower in foregut and higher in midgut and hindgut. We detected Francisella genetic material (DNA) in fish stimulated with a high dose from day 1-28 in foregut, midgut, and hindgut. However, we could only detect Francisella DNA in fish stimulated the medium and low dose at later timepoints in the foregut (21-28 days post injection "dpi") and hindgut (low dose from day 7-28 dpi). Our results suggest that the immune responses to bacterial pathogens occur throughout the gut, but certain segments may be more susceptible to infection because of their cellular morphology (anterior, middle and posterior).
Collapse
Affiliation(s)
- Daniela Díaz-Ibarrola
- 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; Escuela de Graduados, Programa de Doctorado en Ciencias de la Acuicultura, Universidad Austral de Chile, Puerto Montt, Chile.
| | - Danixa Martínez
- Laboratorio de Fisiología de Peces, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Laboratorio de Inmunología y Estrés de Organismos Acuáticos, Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Carolina Vargas-Lagos
- 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
| | - Julia Saravia
- 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; Escuela de Graduados, Programa de Doctorado en Ciencias de la Acuicultura, Universidad Austral de Chile, Puerto Montt, 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.
| |
Collapse
|
8
|
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] [Key Words] [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.
Collapse
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
| | - 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
| | - 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
| |
Collapse
|
9
|
Abstract
Temperature is one of the ubiquitous signals that control both the development as well as virulence of various microbial species. Therefore their survival is dependent upon initiating appropriate response upon temperature fluctuations. In particular, pathogenic microbes exploit host-temperature sensing mechanisms for triggering the expression of virulence genes. Many studies have revealed that the biomolecules within a cell such as DNA, RNA, lipids and proteins help in sensing change in temperature, thereby acting as thermosensors. This review shall provide an insight into the different mechanisms of thermosensing and how they aid pathogenic microbes in host invasion.
Collapse
|
10
|
Ozanic M, Marecic V, Knezevic M, Kelava I, Stojková P, Lindgren L, Bröms JE, Sjöstedt A, Abu Kwaik Y, Santic M. The type IV pili component PilO is a virulence determinant of Francisella novicida. PLoS One 2022; 17:e0261938. [PMID: 35077486 PMCID: PMC8789160 DOI: 10.1371/journal.pone.0261938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 12/14/2021] [Indexed: 12/03/2022] Open
Abstract
Francisella tularensis is a highly pathogenic intracellular bacterium that causes the disease tularemia. While its ability to replicate within cells has been studied in much detail, the bacterium also encodes a less characterised type 4 pili (T4P) system. T4Ps are dynamic adhesive organelles identified as major virulence determinants in many human pathogens. In F. tularensis, the T4P is required for adherence to the host cell, as well as for protein secretion. Several components, including pilins, a pili peptidase, a secretin pore and two ATPases, are required to assemble a functional T4P, and these are encoded within distinct clusters on the Francisella chromosome. While some of these components have been functionally characterised, the role of PilO, if any, still is unknown. Here, we examined the role of PilO in the pathogenesis of F. novicida. Our results show that the PilO is essential for pilus assembly on the bacterial surface. In addition, PilO is important for adherence of F. novicida to human monocyte-derived macrophages, secretion of effector proteins and intracellular replication. Importantly, the pilO mutant is attenuated for virulence in BALB/c mice regardless of the route of infection. Following intratracheal and intradermal infection, the mutant caused no histopathology changes, and demonstrated impaired phagosomal escape and replication within lung liver as well as spleen. Thus, PilO is an essential virulence determinant of F. novicida.
Collapse
Affiliation(s)
- Mateja Ozanic
- Faculty of Medicine, Department of Microbiology and Parasitology, University of Rijeka, Rijeka, Croatia
| | - Valentina Marecic
- Faculty of Medicine, Department of Microbiology and Parasitology, University of Rijeka, Rijeka, Croatia
| | - Masa Knezevic
- Faculty of Medicine, Department of Microbiology and Parasitology, University of Rijeka, Rijeka, Croatia
| | - Ina Kelava
- Faculty of Medicine, Department of Microbiology and Parasitology, University of Rijeka, Rijeka, Croatia
| | - Pavla Stojková
- Department of Clinical Microbiology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Lena Lindgren
- Department of Clinical Microbiology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Jeanette E. Bröms
- Department of Clinical Microbiology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Anders Sjöstedt
- Department of Clinical Microbiology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology and Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, Kentucky, United States of America
| | - Marina Santic
- Faculty of Medicine, Department of Microbiology and Parasitology, University of Rijeka, Rijeka, Croatia
| |
Collapse
|
11
|
Quilapi AM, Vargas-Lagos C, Martínez D, Muñoz JL, Spies J, Esperguel I, Tapia J, Oyarzún-Salazar R, Vargas-Chacoff L. Brain immunity response of fish Eleginops maclovinus to infection with Francisella noatunensis. FISH & SHELLFISH IMMUNOLOGY 2022; 120:695-705. [PMID: 34808359 DOI: 10.1016/j.fsi.2021.11.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 06/13/2023]
Abstract
The brain's immune system is selective and hermetic in most species, including fish, favoring immune responses mediated by soluble immunomodulatory factors such as serotonin and the availability of nutrients against infectious processes. Francisella noatunensis coexist with fish such as Eleginops maclovinus, which raises questions about the susceptibility and immune response of the brain of E. maclovinus against Francisella. In this study, we inoculated fish with different doses of Francisella and took samples for 28 days. We detected bacteria in the brain of fish injected with a high concentration of Francisella at all time points. qPCR analysis of immune genes indicated a response mainly in the medium-dose and early expression of genes involved in iron metabolism. Finally, brain serotonin levels were higher than in uninfected fish in all conditions, suggesting possible immunomodulatory participation in an infectious process.
Collapse
Affiliation(s)
- Ana María Quilapi
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Universidad Santo Tomás, Osorno, Chile; Magister en Ciencias Mención Microbiología, Universidad Austral de Chile, Valdivia, Chile.
| | - Carolina Vargas-Lagos
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile
| | - Danixa Martínez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Jose Luis Muñoz
- Centro de Investigación y Desarrollo i ∼ mar, Universidad de los Lagos, Casilla 557, Puerto Montt, Chile
| | - Johana Spies
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Ivan Esperguel
- Magister en Ciencias Mención Microbiología, Universidad Austral de Chile, Valdivia, Chile
| | - Jaime Tapia
- Institute of Chemistry and Natural Resources, Universidad de Talca, Chile
| | | | - Luis Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
| |
Collapse
|
12
|
Chin CY, Zhao J, Llewellyn AC, Golovliov I, Sjöstedt A, Zhou P, Weiss DS. Francisella FlmX broadly affects lipopolysaccharide modification and virulence. Cell Rep 2021; 35:109247. [PMID: 34133919 DOI: 10.1016/j.celrep.2021.109247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 01/14/2021] [Accepted: 05/20/2021] [Indexed: 10/21/2022] Open
Abstract
The outer membrane protects Gram-negative bacteria from the host environment. Lipopolysaccharide (LPS), a major outer membrane constituent, has distinct components (lipid A, core, O-antigen) generated by specialized pathways. In this study, we describe the surprising convergence of these pathways through FlmX, an uncharacterized protein in the intracellular pathogen Francisella. FlmX is in the flippase family, which includes proteins that traffic lipid-linked envelope components across membranes. flmX deficiency causes defects in lipid A modification, core remodeling, and O-antigen addition. We find that an F. tularensis mutant lacking flmX is >1,000,000-fold attenuated. Furthermore, FlmX is required to resist the innate antimicrobial LL-37 and the antibiotic polymyxin. Given FlmX's central role in LPS modification and its conservation in intracellular pathogens Brucella, Coxiella, and Legionella, FlmX may represent a novel drug target whose inhibition could cripple bacterial virulence and sensitize bacteria to innate antimicrobials and antibiotics.
Collapse
Affiliation(s)
- Chui-Yoke Chin
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Jinshi Zhao
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Anna C Llewellyn
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Igor Golovliov
- Clinical Bacteriology, and Laboratory for Molecular Infection Medicine Sweden, Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden
| | - Anders Sjöstedt
- Clinical Bacteriology, and Laboratory for Molecular Infection Medicine Sweden, Department of Clinical Microbiology, Umeå University, 90185 Umeå, Sweden
| | - Pei Zhou
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - David S Weiss
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, GA 30329, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30329, USA; Research Service, Atlanta VA Medical Center, Decatur, GA 30033, USA.
| |
Collapse
|
13
|
Roy S, Naha S, Rao A, Basu S. CRISPR-Cas system, antibiotic resistance and virulence in bacteria: Through a common lens. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 178:123-174. [PMID: 33685595 DOI: 10.1016/bs.pmbts.2020.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CRISPR-Cas system, antibiotic resistance and virulence are different modes of survival for the bacteria. CRISPR-Cas is an adaptive immune system that can degrade foreign DNA, antibiotic resistance helps bacteria to evade drugs that can threaten their existence and virulence determinants are offensive tools that can facilitate the establishment of infection by pathogens. This chapter focuses on these three aspects, providing insights about the CRISPR system and resistance mechanisms in brief, followed by understanding the synergistic or antagonistic relationship of resistance and virulence determinants in connection to the CRISPR system. We have addressed the discussion of this evolving topic through specific examples and studies. Different approaches for successful detection of this unique defense system in bacteria and various applications of the CRISPR-Cas systems to show how it can be harnessed to tackle the increasing problem of antibiotic resistance have been put forth. World Health Organization has declared antibiotic resistance as a serious global problem of the 21st century. As antibiotic-resistant bacteria increase their footprint across the globe, newer tools such as the CRISPR-Cas system hold immense promise to tackle this problem.
Collapse
Affiliation(s)
- Subhasree Roy
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Scheme XM, Beliaghata, Kolkata, India
| | - Sharmi Naha
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Scheme XM, Beliaghata, Kolkata, India
| | - Ankur Rao
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Scheme XM, Beliaghata, Kolkata, India
| | - Sulagna Basu
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Scheme XM, Beliaghata, Kolkata, India.
| |
Collapse
|
14
|
Zellner B, Mengin-Lecreulx D, Tully B, Gunning WT, Booth R, Huntley JF. A Francisella tularensis L,D-carboxypeptidase plays important roles in cell morphology, envelope integrity, and virulence. Mol Microbiol 2021; 115:1357-1378. [PMID: 33469978 DOI: 10.1111/mmi.14685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/15/2022]
Abstract
Francisella tularensis is a Gram-negative, intracellular bacterium that causes the zoonotic disease tularemia. Intracellular pathogens, including F. tularensis, have evolved mechanisms to survive in the harsh environment of macrophages and neutrophils, where they are exposed to cell envelope-damaging molecules. The bacterial cell wall, primarily composed of peptidoglycan (PG), maintains cell morphology, structure, and membrane integrity. Intracellular Gram-negative bacteria protect themselves from macrophage and neutrophil killing by recycling and repairing damaged PG--a process that involves over 50 different PG synthesis and recycling enzymes. Here, we identified a PG recycling enzyme, L,D-carboxypeptidase A (LdcA), of F. tularensis that is responsible for converting PG tetrapeptide stems to tripeptide stems. Unlike E. coli LdcA and most other orthologs, F. tularensis LdcA does not localize to the cytoplasm and also exhibits L,D-endopeptidase activity, converting PG pentapeptide stems to tripeptide stems. Loss of F. tularensis LdcA led to altered cell morphology and membrane integrity, as well as attenuation in a mouse pulmonary infection model and in primary and immortalized macrophages. Finally, an F. tularensis ldcA mutant protected mice against virulent Type A F. tularensis SchuS4 pulmonary challenge.
Collapse
Affiliation(s)
- Briana Zellner
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH, USA
| | - Dominique Mengin-Lecreulx
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Brenden Tully
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH, USA
| | | | - Robert Booth
- Department of Pathology, University of Toledo, Toledo, OH, USA
| | - Jason F Huntley
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH, USA
| |
Collapse
|
15
|
Nakamura T, Shimizu T, Inagaki F, Okazaki S, Saha SS, Uda A, Watanabe K, Watarai M. Identification of Membrane-Bound Lytic Murein Transglycosylase A (MltA) as a Growth Factor for Francisella novicida in a Silkworm Infection Model. Front Cell Infect Microbiol 2021; 10:581864. [PMID: 33553001 PMCID: PMC7862118 DOI: 10.3389/fcimb.2020.581864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/04/2020] [Indexed: 12/22/2022] Open
Abstract
Francisella tularensis, the causative agent of tularemia, is transmitted by arthropod vectors within mammalian hosts. The detailed mechanisms contributing to growth and survival of Francisella within arthropod remain poorly understood. To identify novel factors supporting growth and survival of Francisella within arthropods, a transposon mutant library of F. tularensis subsp. novicida (F. novicida) was screened using an F. novicida-silkworm infection model. Among 750 transposon mutants screened, the mltA-encoding membrane-bound lytic murein transglycosylase A (MltA) was identified as a novel growth factor of F. novicida in silkworms. Silkworms infection with an mltA deletion mutant (ΔmltA) resulted in a reduction in the number of bacteria and prolonged survival. The ΔmltA strain exhibited limited intracellular growth and cytotoxicity in BmN4 silkworm ovary cells. Moreover, the ΔmltA strain induced higher expression of the antimicrobial peptide in silkworms compared to the wild-type strain. These results suggest that F. novicida MltA contributes to the survival of F. novicida in silkworms via immune suppression-related mechanisms. Intracellular growth of the ΔmltA strain was also reduced in human monocyte THP-1 cells. These results also suggest the contribution of MltA to pathogenicity in humans and utility of the F. novicida-silkworm infection model to explore Francisella infection.
Collapse
Affiliation(s)
- Takemasa Nakamura
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Takashi Shimizu
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Fumiya Inagaki
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Shoma Okazaki
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Shib Shankar Saha
- Department of Pathology and Parasitology, Patuakhali Science and Technology University, Barisal, Bangladesh
| | - Akihiko Uda
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenta Watanabe
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Masahisa Watarai
- Laboratory of Veterinary Public Health, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| |
Collapse
|
16
|
The Use of Extracellular Membrane Vesicles for Immunization against Francisellosis in Nile Tilapia ( Oreochromis niloticus) and Atlantic Cod ( Gadus morhua L.). Vaccines (Basel) 2021; 9:vaccines9010034. [PMID: 33435503 PMCID: PMC7827370 DOI: 10.3390/vaccines9010034] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 11/17/2022] Open
Abstract
Francisellosis in fish is caused by the facultative intracellular Gram-negative bacterial pathogens Francisella noatunensis ssp. noatunensis and Francisella orientalis. The disease is affecting both farmed and wild fish worldwide and no commercial vaccines are currently available. In this study, we tested isolated membrane vesicles (MVs) as possible vaccine candidates based on previous trials in zebrafish (Danio rerio) indicating promising vaccine efficacy. Here, the MV vaccine-candidates were tested in their natural hosts, Atlantic cod (Gadus morhua L.) and Nile tilapia (Oreochromis niloticus). Injection of MVs did not display any toxicity or other negative influence on the fish and gene expression analysis indicated an influence on the host immune response. However, unlike in other tested fish species, a protective immunity following vaccine application and immunization period could not be detected in the Atlantic cod or tilapia. Further in vivo studies are required to achieve a better understanding of the development of immunological memory in different fish species.
Collapse
|
17
|
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: 9] [Impact Index Per Article: 2.3] [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.
Collapse
|
18
|
The Sensor Kinase QseC Regulates the Unlinked PmrA Response Regulator and Downstream Gene Expression in Francisella. J Bacteriol 2020; 202:JB.00321-20. [PMID: 32839173 DOI: 10.1128/jb.00321-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/13/2020] [Indexed: 12/22/2022] Open
Abstract
The facultative intracellular bacterial pathogen Francisella tularensis is the causative agent of tularemia in humans and animals. Gram-negative bacteria utilize two-component regulatory systems (TCS) to sense and respond to their changing environment. No classical, tandemly arranged sensor kinase and response regulator TCS genes exist in the human virulent Francisella tularensis subsp. tularensis, but orphaned members are present. PmrA is an orphan response regulator responsible for intramacrophage growth and virulence; however, the regulation of PmrA activity is not understood. We and others have shown that PmrA represses the expression of priM, described to encode an antivirulence determinant. By screening a mutant library for increased priM promoter activity, we identified the sensor kinase homolog QseC as an upstream regulator of priM expression, and this regulation is in part dependent upon the aspartate phosphorylation site of PmrA (D51). Several examined environmental signals, including epinephrine, which is reported to activate QseC in other bacteria, do not affect priM expression in a manner dependent on PmrA. Intramacrophage survival assays also question the finding that PriM is an antivirulence factor. Thus, these data suggest that the PmrA-regulated gene priM is modulated by the QseC-PmrA (QseB) TCS in Francisella IMPORTANCE The disease tularemia is caused by the highly infectious Gram-negative pathogen Francisella tularensis This bacterium encodes few regulatory factors (e.g., two-component systems [TCS]). PmrA, required for intramacrophage survival and virulence in the mouse model, is encoded by an orphan TCS response regulator gene. It is unclear how PmrA is responsive to environmental signals to regulate loci, including the PmrA-repressed gene priM We identify an orphan sensor kinase (QseC) that is required for priM repression and further explore both environmental signals that might regulate the QseC-PmrA TCS and the function of PriM.
Collapse
|
19
|
Kelava I, Mihelčić M, Ožanič M, Marečić V, Knežević M, Ćurlin M, Štifter S, Sjöstedt A, Šantić M. Atg5-Deficient Mice Infected with Francisella tularensis LVS Demonstrate Increased Survival and Less Severe Pathology in Internal Organs. Microorganisms 2020; 8:microorganisms8101531. [PMID: 33036147 PMCID: PMC7600933 DOI: 10.3390/microorganisms8101531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 12/19/2022] Open
Abstract
Francisella tularensis is a highly virulent intracellular pathogen that proliferates within various cell types and can infect a multitude of animal species. Francisella escapes the phagosome rapidly after infection and reaches the host cell cytosol where bacteria undergo extensive replication. Once cytosolic, Francisella becomes a target of an autophagy-mediated process. The mechanisms by which autophagy plays a role in replication of this cytosolic pathogen have not been fully elucidated. In vitro, F. tularensis avoids degradation via autophagy and the autophagy process provides nutrients that support its intracellular replication, but the role of autophagy in vivo is unknown. Here, we investigated the role of autophagy in the pathogenesis of tularemia by using transgenic mice deficient in Atg5 in the myeloid lineage. The infection of Atg5-deficient mice with Francisella tularensis subsp. holarctica live vaccine strain (LVS) resulted in increased survival, significantly reduced bacterial burden in the mouse organs, and less severe histopathological changes in the spleen, liver and lung tissues. The data highlight the contribution of Atg5 in the pathogenesis of tularemia in vivo.
Collapse
Affiliation(s)
- Ina Kelava
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
| | - Mirna Mihelčić
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
| | - Mateja Ožanič
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
| | - Valentina Marečić
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
| | - Maša Knežević
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
| | - Marija Ćurlin
- Department of Histology and Embryology, Faculty of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
| | - Sanja Štifter
- Department of Pathology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia;
| | - Anders Sjöstedt
- Department of Clinical Microbiology, Umeå University, 901 85 Umeå, Sweden;
| | - Marina Šantić
- Department of Microbiology and Parasitology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia; (I.K.); (M.M.); (M.O.); (V.M.); (M.K.)
- Correspondence:
| |
Collapse
|
20
|
Sutera V, Hennebique A, Lopez F, Fernandez N, Schneider D, Maurin M. Genomic trajectories to fluoroquinolone resistance in Francisella tularensis subsp. holarctica live vaccine strain. Int J Antimicrob Agents 2020; 56:106153. [PMID: 32911069 DOI: 10.1016/j.ijantimicag.2020.106153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 07/04/2020] [Accepted: 08/29/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Fluoroquinolone (FQ)-resistant mutants were previously selected from the live vaccine strain (LVS) of Francisella tularensis (F. tularensis) subsp. holarctica. This study further characterised all genetic changes that occurred in these mutants during the evolutionary trajectory toward high-level FQ resistance, and their potential impact on F. tularensis antibiotic resistance and intracellular fitness. METHODS The whole genomes of FQ-resistant mutants were determined and compared with those of their parental strain. All detected mutations were evaluated for their potential impact on FQ resistance and intracellular multiplication of F. tularensis. RESULTS As compared with the parental LVS genome, 28 mutations were found in the derived FQ-resistant mutants. These mutations involved all genes encoding type II topoisomerases (i.e. gyrA, gyrB, parC, and parE). Interestingly, some of them were not previously associated with FQ resistance, warranting further characterisation. Mutations associated with FQ resistance were also found in other genes, including three encoding proteins involved in transport processes. Most of the detected mutations did not alter multiplication of the corresponding mutants in J774 cells. In contrast, all mutations at locus FTL_0439 encoding FupA/B, a membrane protein involved in iron transport, were associated with FQ resistance and fitness loss. CONCLUSION FQ resistance in F. tularensis is complex and may involve single or combined mutations in genes encoding type II topoisomerases, transport systems and FupA/B. In vivo studies are now required to assess the potential role of these mutations in FQ treatment failures.
Collapse
Affiliation(s)
- Vivien Sutera
- Centre National de Référence Francisella tularensis, Laboratoire de Bactériologie, Institut de Biologie et de Pathologie, CHU Grenoble Alpes, Grenoble, France; Laboratoire Techniques de l'Ingénierie Médicale et de la Complexité Informatique - Mathématiques et Applications (TIMC-IMAG), Univ. Grenoble Alpes, Centre National de la Recherche Scientifique (CNRS), Grenoble, France
| | - Aurélie Hennebique
- Centre National de Référence Francisella tularensis, Laboratoire de Bactériologie, Institut de Biologie et de Pathologie, CHU Grenoble Alpes, Grenoble, France; Laboratoire Techniques de l'Ingénierie Médicale et de la Complexité Informatique - Mathématiques et Applications (TIMC-IMAG), Univ. Grenoble Alpes, Centre National de la Recherche Scientifique (CNRS), Grenoble, France
| | - Fabrice Lopez
- Technological Advances for Genomics and Clinics (TAGC), Univ. Aix-Marseille II, Marseille, France; Transcriptomic and Genomic Marseille-Luminy (TGML), IBiSA platform, Marseille, France
| | - Nicolas Fernandez
- Technological Advances for Genomics and Clinics (TAGC), Univ. Aix-Marseille II, Marseille, France; Transcriptomic and Genomic Marseille-Luminy (TGML), IBiSA platform, Marseille, France
| | - Dominique Schneider
- Laboratoire Techniques de l'Ingénierie Médicale et de la Complexité Informatique - Mathématiques et Applications (TIMC-IMAG), Univ. Grenoble Alpes, Centre National de la Recherche Scientifique (CNRS), Grenoble, France
| | - Max Maurin
- Centre National de Référence Francisella tularensis, Laboratoire de Bactériologie, Institut de Biologie et de Pathologie, CHU Grenoble Alpes, Grenoble, France; Laboratoire Techniques de l'Ingénierie Médicale et de la Complexité Informatique - Mathématiques et Applications (TIMC-IMAG), Univ. Grenoble Alpes, Centre National de la Recherche Scientifique (CNRS), Grenoble, France.
| |
Collapse
|
21
|
Parashar K, Carpino N. A role for the Sts phosphatases in negatively regulating IFNγ-mediated production of nitric oxide in monocytes. IMMUNITY INFLAMMATION AND DISEASE 2020; 8:523-533. [PMID: 32841534 PMCID: PMC7654413 DOI: 10.1002/iid3.336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/01/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022]
Abstract
Introduction The atypical Sts phosphatases negatively regulate signaling pathways in diverse immune cell types, with two of their molecular targets being the related kinases Syk and Zap‐70. Mice lacking Sts expression (Sts−/−) are resistant to infection by the live vaccine strain (LVS) of Francisella tularensis. Although the mechanisms underlying the enhanced resistance of Sts−/− mice have not been definitively established, Sts−/− bone marrow‐derived monocytes (BMMs) demonstrate greater clearance of intracellular LVS following ex vivo infection, relative to wild type cells. To determine how the Sts proteins regulate monocyte bactericidal properties, we analyzed responses of infected cells. Methods Monocyte bacterial clearance was assayed using ex vivo coculture infections followed by colony‐forming unit analysis of intracellular bacteria. Levels of gene expression were quantified by quantitative reverse‐transcription polymerase chain reaction, levels of Nos2 protein levels were quantified by Western blot analysis, and levels of nitric oxide (NO) were quantified directly using the Griess reagent. We characterized monocyte cytokine production via enzyme‐linked immunosorbent assay. Results We demonstrate that Sts−/− monocyte cultures produce elevated levels of interferon‐γ (IFNγ) after infection, relative to wild type cultures. Sts−/− monocytes also demonstrate heightened responsiveness to IFNγ. Specifically, Sts−/− monocytes produce elevated levels of antimicrobial NO following IFNγ stimulation, and this NO plays an important role in LVS restriction. Additional IFNγ‐stimulated genes, including Ip10 and members of the Gbp gene family, also display heightened upregulation in Sts−/− cells. Both Sts‐1 and Sts‐2 contribute to the regulation of NO production, as evidenced by the responses of monocytes lacking each phosphatase individually. Finally, we demonstrate that the elevated production of IFNγ‐induced NO in Sts−/− monocytes is abrogated following chemical inhibition of Syk kinase. Conclusion Our results indicate a novel role for the Sts enzymes in regulating monocyte antibacterial responses downstream of IFNγ.
Collapse
Affiliation(s)
- Kaustubh Parashar
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York
| | - Nicholas Carpino
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York
| |
Collapse
|
22
|
Carruthers J, Lythe G, López-García M, Gillard J, Laws TR, Lukaszewski R, Molina-París C. Stochastic dynamics of Francisella tularensis infection and replication. PLoS Comput Biol 2020; 16:e1007752. [PMID: 32479491 PMCID: PMC7304631 DOI: 10.1371/journal.pcbi.1007752] [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: 07/17/2019] [Revised: 06/19/2020] [Accepted: 02/27/2020] [Indexed: 12/12/2022] Open
Abstract
We study the pathogenesis of Francisella tularensis infection with an experimental mouse model, agent-based computation and mathematical analysis. Following inhalational exposure to Francisella tularensis SCHU S4, a small initial number of bacteria enter lung host cells and proliferate inside them, eventually destroying the host cell and releasing numerous copies that infect other cells. Our analysis of disease progression is based on a stochastic model of a population of infectious agents inside one host cell, extending the birth-and-death process by the occurrence of catastrophes: cell rupture events that affect all bacteria in a cell simultaneously. Closed expressions are obtained for the survival function of an infected cell, the number of bacteria released as a function of time after infection, and the total bacterial load. We compare our mathematical analysis with the results of agent-based computation and, making use of approximate Bayesian statistical inference, with experimental measurements carried out after murine aerosol infection with the virulent SCHU S4 strain of the bacterium Francisella tularensis, that infects alveolar macrophages. The posterior distribution of the rate of replication of intracellular bacteria is consistent with the estimate that the time between rounds of bacterial division is less than 6 hours in vivo. Infecting a host cell is required for the replication of many types of bacteria and viruses. In some cases, infected cells release new infectious agents continuously over their lifetime. In others, such as the Francisella tularensis bacterium studied here, they are released in a single burst that coincides with the cell’s death. We show how a stochastic model, the birth-and-death process with catastrophe, can be used to characterise infection in a single cell, thereby allowing us to account for burst events and quantify the kinetics of pathogenesis in the lung, the initial site of infection, as well as in other organs that the infection spreads to. We learn about the parameters of the mathematical model of Francisella tularensis infection making use of the experimental measurements of bacterial loads, together with approximate Bayesian statistical inference methods. The most important parameter describing the pathogenesis is the rate of replication of intracellular bacteria.
Collapse
Affiliation(s)
- Jonathan Carruthers
- Department of Applied Mathematics, University of Leeds, Leeds, United Kingdom
| | - Grant Lythe
- Department of Applied Mathematics, University of Leeds, Leeds, United Kingdom
| | - Martín López-García
- Department of Applied Mathematics, University of Leeds, Leeds, United Kingdom
| | - Joseph Gillard
- CBR Division, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Thomas R. Laws
- CBR Division, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Roman Lukaszewski
- CBR Division, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Carmen Molina-París
- Department of Applied Mathematics, University of Leeds, Leeds, United Kingdom
- * E-mail:
| |
Collapse
|
23
|
Dean SN, Milton ME, Cavanagh J, van Hoek ML. Francisella novicida Two-Component System Response Regulator BfpR Modulates iglC Gene Expression, Antimicrobial Peptide Resistance, and Biofilm Production. Front Cell Infect Microbiol 2020; 10:82. [PMID: 32232010 PMCID: PMC7082314 DOI: 10.3389/fcimb.2020.00082] [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: 12/01/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Response regulators are a critical part of the two-component system of gene expression regulation in bacteria, transferring a signal from a sensor kinase into DNA binding activity resulting in alteration of gene expression. In this study, we investigated a previously uncharacterized response regulator in Francisella novicida, FTN_1452 that we have named BfpR (Biofilm-regulating Francisella protein Regulator, FTN_1452). In contrast to another Francisella response regulator, QseB/PmrA, BfpR appears to be a negative regulator of biofilm production, and also a positive regulator of antimicrobial peptide resistance in this bacterium. The protein was crystallized and X-ray crystallography studies produced a 1.8 Å structure of the BfpR N-terminal receiver domain revealing interesting insight into its potential interaction with the sensor kinase. Structural analysis of BfpR places it in the OmpR/PhoP family of bacterial response regulators along with WalR and ResD. Proteomic and transcriptomic analyses suggest that BfpR overexpression affects expression of the critical Francisella virulence factor iglC, as well as other proteins in the bacterium. We demonstrate that mutation of bfpR is associated with an antimicrobial peptide resistance phenotype, a phenotype also associated with other response regulators, for the human cathelicidin peptide LL-37 and a sheep antimicrobial peptide SMAP-29. F. novicida with mutated bfpR replicated better than WT in intracellular infection assays in human-derived macrophages suggesting that the down-regulation of iglC expression in bfpR mutant may enable this intracellular replication to occur. Response regulators have been shown to play important roles in the regulation of bacterial biofilm production. We demonstrate that F. novicida biofilm formation was highly increased in the bfpR mutant, corresponding to altered glycogen synthesis. Waxworm infection experiments suggest a role of BfpR as a negative modulator of iglC expression with de-repression by Mg2+. In this study, we find that the response regulator BfpR may be a negative regulator of biofilm formation, and a positive regulator of antimicrobial peptide resistance in F. novicida.
Collapse
Affiliation(s)
- Scott N Dean
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Morgan E Milton
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Monique L van Hoek
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| |
Collapse
|
24
|
Nakamura T, Shimizu T, Uda A, Watanabe K, Watarai M. Soluble lytic transglycosylase SLT of Francisella novicida is involved in intracellular growth and immune suppression. PLoS One 2019; 14:e0226778. [PMID: 31877174 PMCID: PMC6932806 DOI: 10.1371/journal.pone.0226778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022] Open
Abstract
Francisella tularensis, a category-A bioterrorism agent causes tularemia. F. tularensis suppresses the immune response of host cells and intracellularly proliferates. However, the detailed mechanisms of immune suppression and intracellular growth are largely unknown. Here we developed a transposon mutant library to identify novel pathogenic factors of F. tularensis. Among 750 transposon mutants of F. tularensis subsp. novicida (F. novicida), 11 were isolated as less cytotoxic strains, and the genes responsible for cytotoxicity were identified. Among them, the function of slt, which encodes soluble lytic transglycosylase (SLT) was investigated in detail. An slt deletion mutant (Δslt) was less toxic to the human monocyte cell line THP-1 vs the wild-type strain. Although the wild-type strain proliferated in THP-1 cells, the number of intracellular Δslt mutant decreased in comparison. The Δslt mutant escaped from phagosomes during the early stages of infection, but the mutant was detected within the autophagosome, followed by degradation in lysosomes. Moreover, the Δslt mutant induced host cells to produce high levels of cytokines such as tumor necrosis factor-α, interleukin (IL)-6, and IL-1β, compared with the wild-type strain. These results suggest that the SLT of F. novicida is required for immune suppression and escape from autophagy to allow its survival in host cells.
Collapse
Affiliation(s)
- Takemasa Nakamura
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
| | - Takashi Shimizu
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
| | - Akihiko Uda
- Department of Veterinary Science, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Kenta Watanabe
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
| | - Masahisa Watarai
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, Yamaguchi, Japan
- * E-mail:
| |
Collapse
|
25
|
Nau GJ, Horzempa J, O’Dee D, Brown MJ, Russo BC, Hernandez A, Dillon ST, Cheng J, Kane LP, Sanker S, Hukriede NA. A predicted Francisella tularensis DXD-motif glycosyltransferase blocks immune activation. Virulence 2019; 10:643-656. [PMID: 31314675 PMCID: PMC6650193 DOI: 10.1080/21505594.2019.1631662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 02/04/2023] Open
Abstract
Pathogens enhance their survival during infections by manipulating host defenses. Francisella tularensis evades innate immune responses, which we have found to be dependent on an understudied gene ybeX (FTL_0883/FTT_0615c). To understand the function of YbeX, we sought protein interactors in F. tularensis subsp. holarctica live vaccine strain (LVS). An unstudied Francisella protein co-immunoprecipitated with recombinant YbeX, which is a predicted glycosyltransferase with a DXD-motif. There are up to four genomic copies of this gene with identical sequence in strains of F. tularensis pathogenic to humans, despite ongoing genome decay. Disruption mutations were generated by intron insertion into all three copies of this glycosyltransferase domain containing gene in LVS, gdcA1-3. The resulting strains stimulated more cytokines from macrophages in vitro than wild-type LVS and were attenuated in two in vivo infection models. GdcA was released from LVS during culture and was sufficient to block NF-κB activation when expressed in eukaryotic cells. When co-expressed in zebrafish, GdcA and YbeX were synergistically lethal to embryo development. Glycosyltransferases with DXD-motifs are found in a variety of pathogens including NleB, an Escherichia coli type-III secretion system effector that inhibits NF-κB by antagonizing death receptor signaling. To our knowledge, GdcA is the first DXD-motif glycosyltransferase that inhibits NF-κB in immune cells. Together, these findings suggest DXD-motif glycosyltransferases may be a conserved virulence mechanism used by pathogenic bacteria to remodel host defenses.
Collapse
Affiliation(s)
- Gerard J. Nau
- Division of Infectious Diseases, Alpert Medical School of Brown University, Providence, RI, USA
| | - Joseph Horzempa
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV, USA
| | - Dawn O’Dee
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Matthew J. Brown
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Brian C. Russo
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ana Hernandez
- Division of Infectious Diseases, Alpert Medical School of Brown University, Providence, RI, USA
| | - Simon T. Dillon
- Beth Israel Deaconess Medical Center Genomics, Proteomics, and Systems Biology Center, Harvard Medical School, Boston, MA, USA
| | - Jing Cheng
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Lawrence P. Kane
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Subramaniam Sanker
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Neil A. Hukriede
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
26
|
Klimentova J, Pavkova I, Horcickova L, Bavlovic J, Kofronova O, Benada O, Stulik J. Francisella tularensis subsp. holarctica Releases Differentially Loaded Outer Membrane Vesicles Under Various Stress Conditions. Front Microbiol 2019; 10:2304. [PMID: 31649645 PMCID: PMC6795709 DOI: 10.3389/fmicb.2019.02304] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/20/2019] [Indexed: 11/16/2022] Open
Abstract
Francisella tularensis is a Gram-negative, facultative intracellular bacterium, causing a severe disease called tularemia. It secretes unusually shaped nanotubular outer membrane vesicles (OMV) loaded with a number of virulence factors and immunoreactive proteins. In the present study, the vesicles were purified from a clinical isolate of subsp. holarctica strain FSC200. We here provide a comprehensive proteomic characterization of OMV using a novel approach in which a comparison of OMV and membrane fraction is performed in order to find proteins selectively enriched in OMV vs. membrane. Only these proteins were further considered to be really involved in the OMV function and/or their exceptional structure. OMV were also isolated from bacteria cultured under various cultivation conditions simulating the diverse environments of F. tularensis life cycle. These included conditions mimicking the milieu inside the mammalian host during inflammation: oxidative stress, low pH, and high temperature (42°C); and in contrast, low temperature (25°C). We observed several-fold increase in vesiculation rate and significant protein cargo changes for high temperature and low pH. Further proteomic characterization of stress-derived OMV gave us an insight how the bacterium responds to the hostile environment of a mammalian host through the release of differentially loaded OMV. Among the proteins preferentially and selectively packed into OMV during stressful cultivations, the previously described virulence factors connected to the unique intracellular trafficking of Francisella were detected. Considerable changes were also observed in a number of proteins involved in the biosynthesis and metabolism of the bacterial envelope components like O-antigen, lipid A, phospholipids, and fatty acids. Data are available via ProteomeXchange with identifier PXD013074.
Collapse
Affiliation(s)
- Jana Klimentova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Ivona Pavkova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Lenka Horcickova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Jan Bavlovic
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Olga Kofronova
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Oldrich Benada
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia.,Faculty of Science, Jan Evangelista Purkyně University, Ústí nad Labem, Czechia
| | - Jiri Stulik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| |
Collapse
|
27
|
Soucy AM, Hurteau GJ, Metzger DW. Live Vaccination Generates Both Disease Tolerance and Host Resistance During Chronic Pulmonary Infection With Highly Virulent Francisella tularensis SchuS4. J Infect Dis 2019; 218:1802-1812. [PMID: 29931113 DOI: 10.1093/infdis/jiy379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 06/18/2018] [Indexed: 11/13/2022] Open
Abstract
Disease tolerance can preserve host homeostasis and limit the negative impact of infections. We report that vaccinated mice survived pulmonary challenge with the extremely virulent SchuS4 strain of Francisella tularensis for at least 100 days, despite the persistence of large numbers (~104) of organisms. Transfer of 100 of these resident bacteria to naive animals caused 100% lethality, demonstrating that virulence was maintained. Tissue damage in the lung was limited over the course of infection and was associated with increased levels of amphiregulin. Mice depleted of CD4+ cells had reduced amphiregulin and succumbed to infection. In addition, neutralization of interferon-γ or depletion of CD8+ cells resulted in increased pathogen loads, bacteremia, and death of the host. Conversely, depletion of Ly6G+ neutrophils had no effect on survival and actually resulted in reduced bacterial levels. Understanding the interplay between host resistance and disease tolerance will provide new insights into the understanding of chronic infectious diseases.
Collapse
Affiliation(s)
- Alicia M Soucy
- Department of Immunology and Microbial Disease, Albany Medical College, New York
| | - Gregory J Hurteau
- Department of Immunology and Microbial Disease, Albany Medical College, New York
| | - Dennis W Metzger
- Department of Immunology and Microbial Disease, Albany Medical College, New York
| |
Collapse
|
28
|
Dominant role of splenic marginal zone lipid rafts in the classical complement pathway against S. pneumoniae. Cell Death Discov 2019; 5:133. [PMID: 31531231 PMCID: PMC6733876 DOI: 10.1038/s41420-019-0213-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/11/2019] [Accepted: 08/18/2019] [Indexed: 12/28/2022] Open
Abstract
Lipid rafts (LRs) play crucial roles in complex physiological processes, modulating innate and acquired immune responses to pathogens. The transmembrane C-type lectins human dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and its mouse homolog SIGN-R1 are distributed in LRs and expressed on splenic marginal zone (MZ) macrophages. The DC-SIGN-C1q or SIGN-R1-C1q complex could mediate the immunoglobulin (Ig)-independent classical complement pathway against Streptococcus pneumoniae. Precise roles of LRs during this complement pathway are unknown. Here we show that LRs are indispensable for accelerating the DC-SIGN- or SIGN-R1-mediated classical complement pathway against S. pneumoniae, thus facilitating rapid clearance of the pathogen. The trimolecular complex of SIGN-R1-C1q-C4 was exclusively enriched in LRs of splenic MZ macrophages and their localization was essential for activating C3 catabolism and enhancing pneumococcal clearance, which were abolished in SIGN-R1-knockout mice. However, DC-SIGN replacement on splenic MZ macrophage’s LRs of SIGN-R1-depleted mice reversed these defects. Disruption of LRs dramatically reduced pneumococcal uptake and decomposition. Additionally, DC- SIGN, C1q, C4, and C3 were obviously distributed in splenic LRs of cadavers. Therefore, LRs on splenic SIGN-R1+ or DC-SIGN+ macrophages could provide spatially confined and optimal bidirectional platforms, not only for usual intracellular events, for example recognition and phagocytosis of pathogens, but also an unusual extracellular event such as the complement system. These findings improve our understanding of the orchestrated roles of the spleen, unraveling a new innate immune system initiated from splenic MZ LRs, and yielding answers to several long-standing problems, including the need to understand the profound role of LRs in innate immunity, the need to identify how such a small portion of splenic SIGN-R1+ macrophages (<0.05% of splenic macrophages) effectively resist S. pneumoniae, and the need to understand how LRs can promote the protective function of DC-SIGN against S. pneumoniae in the human spleen.
Collapse
|
29
|
Molecular Basis of BioJ, a Unique Gatekeeper in Bacterial Biotin Synthesis. iScience 2019; 19:796-808. [PMID: 31494495 PMCID: PMC6733898 DOI: 10.1016/j.isci.2019.08.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/28/2019] [Accepted: 08/19/2019] [Indexed: 11/24/2022] Open
Abstract
Biotin is an indispensable cofactor in the three domains of life. The unusual virulence factor BioJ of Francisella catalyzes the formation of pimeloyl-ACP, an intermediate in biotin synthesis. Here, we report the 1.58 Å crystal structure of BioJ, the enzymatic activity of which is determined with the in vitro reconstituted reaction and biotin bioassay in vivo. Unlike the paradigm BioH, BioJ displays an atypical α/β-hydrolase fold. A structurally conserved catalytic triad (S151, D248, and H278) of BioJ is functionally defined. A proposed model for BioJ catalysis involves two basic residues-rich cavities, of which cavity-1, rather than cavity-2, binds to the ACP moiety of its physiological substrate, pimeloyl-ACP methyl ester. In summary, this finding provides molecular insights into the BioJ gatekeeper of biotin synthesis.
Collapse
|
30
|
Hamblin KA, Flick-Smith H, Barnes KB, Pereira-Leal JB, Surkont J, Hampson R, Atkins HS, Harding SV. Disulfiram, an alcohol dependence therapy, can inhibit the in vitro growth of Francisella tularensis. Int J Antimicrob Agents 2019; 54:85-88. [DOI: 10.1016/j.ijantimicag.2019.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/04/2019] [Accepted: 04/06/2019] [Indexed: 10/27/2022]
|
31
|
Solbakken MH, Jentoft S, Reitan T, Mikkelsen H, Gregers TF, Bakke O, Jakobsen KS, Seppola M. Disentangling the immune response and host-pathogen interactions in Francisella noatunensis infected Atlantic cod. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 30:333-346. [PMID: 31054474 DOI: 10.1016/j.cbd.2019.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 03/08/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022]
Abstract
The genetic repertoire underlying teleost immunity has been shown to be highly variable. A rare example is Atlantic cod and its relatives Gadiformes that lacks a hallmark of vertebrate immunity: Major Histocompatibility Complex class II. No immunological studies so far have fully unraveled the functionality of this particular immune system. Through global transcriptomic profiling, we investigate the immune response and host-pathogen interaction of Atlantic cod infected with the facultative intracellular bacterium Francisella noatunensis. We find that Atlantic cod displays an overall classic innate immune response with inflammation, acute-phase proteins and cell recruitment through up-regulation of e.g. IL1B, fibrinogen, cathelicidin, hepcidin and several chemotactic cytokines such as the neutrophil attractants CXCL1 and CXCL8. In terms of adaptive immunity, we observe up-regulation of interferon gamma followed by up-regulation of several MHCI transcripts and genes related to antigen transport and loading. Finally, we find up-regulation of immunoglobulins and down-regulation of T-cell and NK-like cell markers. Our analyses also uncover some contradictory transcriptional findings such as up-regulation of anti-inflammatory IL10 as well as down-regulation of the NADPH oxidase complex and myeloperoxidase. This we interpret as the result of host-pathogen interactions where F. noatunensis modulates the immune response. In summary, our results suggest that Atlantic cod mounts a classic innate immune response as well as a neutrophil-driven response. In terms of adaptive immunity, both endogenous and exogenous antigens are being presented on MHCI and antibody production is likely enabled through direct B-cell stimulation with possible neutrophil help. Collectively, we have obtained novel insight in the orchestration of the Atlantic cod immune system and determined likely targets of F. noatunensis host-pathogen interactions.
Collapse
Affiliation(s)
- Monica Hongrø Solbakken
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, Oslo, Norway
| | - Sissel Jentoft
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, Oslo, Norway.
| | - Trond Reitan
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, Oslo, Norway
| | | | - Tone F Gregers
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Oddmund Bakke
- Department of Biosciences, Centre for Immune Regulation, University of Oslo, Oslo, Norway
| | - Kjetill S Jakobsen
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, Oslo, Norway
| | - Marit Seppola
- Department of Medical Biology, The Arctic University of Norway, Tromsø, Norway.
| |
Collapse
|
32
|
Bacterial Prison Break: A Host Protein Mimic Paves the Way. Cell Host Microbe 2019; 24:189-191. [PMID: 30092194 DOI: 10.1016/j.chom.2018.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The intracellular pathogen Francisella secretes effector proteins inside host cells; however, their functions have remained unclear. In this issue of Cell Host & Microbe, Ledvina et al. (2018) elucidate the role of one such effector, OpiA, to be a bacterial phosphatidylinositol-3-kinase that alters phagosomal trafficking and can promote intracellular bacterial replication.
Collapse
|
33
|
Ahmed W, Hafeez MA, Ahmad R, Mahmood S. CRISPR-Cas system in regulation of immunity and virulence of bacterial pathogens. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
34
|
Dreier RF, Santos JC, Broz P. Detecting Release of Bacterial dsDNA into the Host Cytosol Using Fluorescence Microscopy. Methods Mol Biol 2018; 1714:199-213. [PMID: 29177864 DOI: 10.1007/978-1-4939-7519-8_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Recognition of pathogens by the innate immune system relies on germline-encoded pattern recognition receptors (PRRs) that recognize unique microbial molecules, so-called pathogen-associated molecular patterns (PAMPs). Nucleic acids and their derivatives are one of the most important groups of PAMPs, and are recognized by a number of surface-associated as well as cytosolic PRRs. Cyclic GMP-AMP synthase (cGAS) recognizes the presence of pathogen- or host-derived dsDNA in the cytosol and initiates type-I-IFN production. Here, we describe a methodology that allows for evaluating the association of cGAS with released bacterial dsDNA during Francisella novicida infection of macrophages, by fluorescence confocal microscopy. This method can be adapted to the study of cGAS-dependent responses elicited by other intracellular bacterial pathogens and in other cell types.
Collapse
Affiliation(s)
- Roland Felix Dreier
- Focal Area Infection Biology, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - José Carlos Santos
- Focal Area Infection Biology, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Petr Broz
- Focal Area Infection Biology, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.
| |
Collapse
|
35
|
Carruthers J, López-García M, Gillard JJ, Laws TR, Lythe G, Molina-París C. A Novel Stochastic Multi-Scale Model of Francisella tularensis Infection to Predict Risk of Infection in a Laboratory. Front Microbiol 2018; 9:1165. [PMID: 30034369 PMCID: PMC6043654 DOI: 10.3389/fmicb.2018.01165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/14/2018] [Indexed: 12/30/2022] Open
Abstract
We present a multi-scale model of the within-phagocyte, within-host and population-level infection dynamics of Francisella tularensis, which extends the mechanistic one proposed by Wood et al. (2014). Our multi-scale model incorporates key aspects of the interaction between host phagocytes and extracellular bacteria, accounts for inter-phagocyte variability in the number of bacteria released upon phagocyte rupture, and allows one to compute the probability of response, and mean time until response, of an infected individual as a function of the initial infection dose. A Bayesian approach is applied to parameterize both the within-phagocyte and within-host models using infection data. Finally, we show how dose response probabilities at the individual level can be used to estimate the airborne propagation of Francisella tularensis in indoor settings (such as a microbiology laboratory) at the population level, by means of a deterministic zonal ventilation model.
Collapse
Affiliation(s)
- Jonathan Carruthers
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds, United Kingdom
| | - Martín López-García
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds, United Kingdom
| | - Joseph J. Gillard
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Thomas R. Laws
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Grant Lythe
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds, United Kingdom
| | - Carmen Molina-París
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
36
|
Cui G, Wang J, Qi X, Su J. Transcription Elongation Factor GreA Plays a Key Role in Cellular Invasion and Virulence of Francisella tularensis subsp. novicida. Sci Rep 2018; 8:6895. [PMID: 29720697 PMCID: PMC5932009 DOI: 10.1038/s41598-018-25271-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/18/2018] [Indexed: 01/24/2023] Open
Abstract
Francisella tularensis is a facultative intracellular Gram-negative bacterium that causes the zoonotic disease tularemia. We identified the transcription elongation factor GreA as a virulence factor in our previous study, but its role was not defined. Here, we investigate the effects of the inactivation of the greA gene, generating a greA mutant of F. tularensis subsp. novicida. Inactivation of greA impaired the bacterial invasion into and growth within host cells, and subsequently virulence in mouse infection model. A transcriptomic analysis (RNA-Seq) showed that the loss of GreA caused the differential expression of 196 bacterial genes, 77 of which were identified as virulence factors in previous studies. To confirm that GreA regulates the expression of virulence factors involved in cell invasion by Francisella, FTN_1186 (pepO) and FTN_1551 (ampD) gene mutants were generated. The ampD deletion mutant showed reduced invasiveness into host cells. These results strongly suggest that GreA plays an important role in the pathogenesis of Francisella by affecting the expression of virulence genes and provide new insights into the complex regulation of Francisella infection.
Collapse
Affiliation(s)
- Guolin Cui
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Jun Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Xinyi Qi
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Jingliang Su
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
| |
Collapse
|
37
|
Hoang KV, Rajaram MVS, Curry HM, Gavrilin MA, Wewers MD, Schlesinger LS. Complement Receptor 3-Mediated Inhibition of Inflammasome Priming by Ras GTPase-Activating Protein During Francisella tularensis Phagocytosis by Human Mononuclear Phagocytes. Front Immunol 2018; 9:561. [PMID: 29632532 PMCID: PMC5879101 DOI: 10.3389/fimmu.2018.00561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/06/2018] [Indexed: 01/08/2023] Open
Abstract
Francisella tularensis is a remarkably infectious facultative intracellular bacterium of macrophages that causes tularemia. Early evasion of host immune responses contributes to the success of F. tularensis as a pathogen. F. tularensis entry into human monocytes and macrophages is mediated by the major phagocytic receptor, complement receptor 3 (CR3, CD11b/CD18). We recently determined that despite a significant increase in macrophage uptake following C3 opsonization of the virulent Type A F. tularensis spp. tularensis Schu S4, this phagocytic pathway results in limited pro-inflammatory cytokine production. Notably, MAP kinase/ERK activation is suppressed immediately during C3-opsonized Schu S4-CR3 phagocytosis. A mathematical model of CR3-TLR2 crosstalk predicted early involvement of Ras GTPase-activating protein (RasGAP) in immune suppression by CR3. Here, we link CR3-mediated uptake of opsonized Schu S4 by human monocytes and macrophages with inhibition of early signal 1 inflammasome activation, evidenced by limited caspase-1 cleavage and IL-18 release. This inhibition is due to increased RasGAP activity, leading to a reduction in the Ras-ERK signaling cascade upstream of the early inflammasome activation event. Thus, our data uncover a novel signaling pathway mediated by CR3 following engagement of opsonized virulent F. tularensis to limit inflammasome activation in human phagocytic cells, thereby contributing to evasion of the host innate immune system.
Collapse
Affiliation(s)
- Ky V Hoang
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Murugesan V S Rajaram
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Heather Marie Curry
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States
| | - Mikhail A Gavrilin
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Internal Medicine, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Mark D Wewers
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Internal Medicine, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Larry S Schlesinger
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States.,Texas Biomedical Research Institute, San Antonio, TX, United States
| |
Collapse
|
38
|
Karki R, Lee E, Place D, Samir P, Mavuluri J, Sharma BR, Balakrishnan A, Malireddi RKS, Geiger R, Zhu Q, Neale G, Kanneganti TD. IRF8 Regulates Transcription of Naips for NLRC4 Inflammasome Activation. Cell 2018; 173:920-933.e13. [PMID: 29576451 DOI: 10.1016/j.cell.2018.02.055] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/17/2018] [Accepted: 02/21/2018] [Indexed: 02/08/2023]
Abstract
Inflammasome activation is critical for host defenses against various microbial infections. Activation of the NLRC4 inflammasome requires detection of flagellin or type III secretion system (T3SS) components by NLR family apoptosis inhibitory proteins (NAIPs); yet how this pathway is regulated is unknown. Here, we found that interferon regulatory factor 8 (IRF8) is required for optimal activation of the NLRC4 inflammasome in bone-marrow-derived macrophages infected with Salmonella Typhimurium, Burkholderia thailandensis, or Pseudomonas aeruginosa but is dispensable for activation of the canonical and non-canonical NLRP3, AIM2, and Pyrin inflammasomes. IRF8 governs the transcription of Naips to allow detection of flagellin or T3SS proteins to mediate NLRC4 inflammasome activation. Furthermore, we found that IRF8 confers protection against bacterial infection in vivo, owing to its role in inflammasome-dependent cytokine production and pyroptosis. Altogether, our findings suggest that IRF8 is a critical regulator of NAIPs and NLRC4 inflammasome activation for defense against bacterial infection.
Collapse
Affiliation(s)
- Rajendra Karki
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ein Lee
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - David Place
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Parimal Samir
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jayadev Mavuluri
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Bhesh Raj Sharma
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Arjun Balakrishnan
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | - Rechel Geiger
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Qifan Zhu
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Geoffrey Neale
- Hartwell Center for Bioinformatics & Biotechnology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | |
Collapse
|
39
|
Trivedi NH, Yu JJ, Hung CY, Doelger RP, Navara CS, Armitige LY, Seshu J, Sinai AP, Chambers JP, Guentzel MN, Arulanandam BP. Microbial co-infection alters macrophage polarization, phagosomal escape, and microbial killing. Innate Immun 2018; 24:152-162. [PMID: 29482417 PMCID: PMC6852389 DOI: 10.1177/1753425918760180] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Macrophages are important innate immune cells that respond to microbial insults.
In response to multi-bacterial infection, the macrophage activation state may
change upon exposure to nascent mediators, which results in different bacterial
killing mechanism(s). In this study, we utilized two respiratory bacterial
pathogens, Mycobacterium bovis (Bacillus Calmette
Guẻrin, BCG) and Francisella tularensis live
vaccine strain (LVS) with different phagocyte evasion mechanisms, as model
microbes to assess the influence of initial bacterial infection on the
macrophage response to secondary infection. Non-activated (M0) macrophages or
activated M2-polarized cells (J774 cells transfected with the mouse IL-4 gene)
were first infected with BCG for 24–48 h, subsequently challenged with LVS, and
the results of inhibition of LVS replication in the macrophages was assessed.
BCG infection in M0 macrophages activated TLR2-MyD88 and Mincle-CARD9 signaling
pathways, stimulating nitric oxide (NO) production and enhanced killing of LVS.
BCG infection had little effect on LVS escape from phagosomes into the cytosol
in M0 macrophages. In contrast, M2-polarized macrophages exhibited enhanced
endosomal acidification, as well as inhibiting LVS replication. Pre-infection
with BCG did not induce NO production and thus did not further reduce LVS
replication. This study provides a model for studies of the complexity of
macrophage activation in response to multi-bacterial infection.
Collapse
Affiliation(s)
- Nikita H Trivedi
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Jieh-Juen Yu
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Chiung-Yu Hung
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Richard P Doelger
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Christopher S Navara
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | | | - Janakiram Seshu
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Anthony P Sinai
- 3 The Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, USA
| | - James P Chambers
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - M Neal Guentzel
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| | - Bernard P Arulanandam
- 1 Department of Biology, the South Texas Center for Emerging Infectious Diseases, and the Center for Excellence in Infection Genomics, University of Texas at San Antonio, USA
| |
Collapse
|
40
|
A Single Mechanosensitive Channel Protects Francisella tularensis subsp. holarctica from Hypoosmotic Shock and Promotes Survival in the Aquatic Environment. Appl Environ Microbiol 2018; 84:AEM.02203-17. [PMID: 29269496 DOI: 10.1128/aem.02203-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.IMPORTANCE The contamination of freshwater by Francisella tularensis subsp. holarctica has resulted in a number of outbreaks of tularemia. Invariably, the contamination originates from the carcasses or excreta of infected animals and thus involves an abrupt osmotic downshock as the bacteria enter freshwater. How F. tularensis survives this drastic change in osmolarity has not been clear, but here we report that a single mechanosensitive channel protects the bacterium from osmotic downshock. This channel is functional despite lacking much of the cytoplasmic vestibule domain that is present in better-studied organisms such as Escherichia coli; this report builds on previous studies that have suggested that parts of this domain are dispensable for downshock protection. These findings extend our understanding of the aquatic cycle and ecological persistence of F. tularensis, with further implications for mechanosensitive channel biology.
Collapse
|
41
|
Mahas A, Neal Stewart C, Mahfouz MM. Harnessing CRISPR/Cas systems for programmable transcriptional and post-transcriptional regulation. Biotechnol Adv 2018; 36:295-310. [DOI: 10.1016/j.biotechadv.2017.11.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/03/2017] [Accepted: 11/27/2017] [Indexed: 12/26/2022]
|
42
|
Host-based lipid inflammation drives pathogenesis in Francisella infection. Proc Natl Acad Sci U S A 2017; 114:12596-12601. [PMID: 29109289 DOI: 10.1073/pnas.1712887114] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mass spectrometry imaging (MSI) was used to elucidate host lipids involved in the inflammatory signaling pathway generated at the host-pathogen interface during a septic bacterial infection. Using Francisella novicida as a model organism, a bacterial lipid virulence factor (endotoxin) was imaged and identified along with host phospholipids involved in the splenic response in murine tissues. Here, we demonstrate detection and distribution of endotoxin in a lethal murine F. novicida infection model, in addition to determining the temporally and spatially resolved innate lipid inflammatory response in both 2D and 3D renderings using MSI. Further, we show that the cyclooxygenase-2-dependent lipid inflammatory pathway is responsible for lethality in F. novicida infection due to overproduction of proinflammatory effectors including prostaglandin E2. The results of this study emphasize that spatial determination of the host lipid components of the immune response is crucial to identifying novel strategies to effectively address highly pathogenic and lethal infections stemming from bacterial, fungal, and viral origins.
Collapse
|
43
|
Mass spectrometry analysis of intact Francisella bacteria identifies lipid A structure remodeling in response to acidic pH stress. Biochimie 2017; 141:16-20. [DOI: 10.1016/j.biochi.2017.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/09/2017] [Indexed: 11/18/2022]
|
44
|
Hoang KV, Adcox HE, Fitch JR, Gordon DM, Curry HM, Schlesinger LS, White P, Gunn JS. AR-13, a Celecoxib Derivative, Directly Kills Francisella In Vitro and Aids Clearance and Mouse Survival In Vivo. Front Microbiol 2017; 8:1695. [PMID: 28955308 PMCID: PMC5600997 DOI: 10.3389/fmicb.2017.01695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/23/2017] [Indexed: 12/15/2022] Open
Abstract
Francisella tularensis (F. tularensis) is the causative agent of tularemia and is classified as a Tier 1 select agent. No licensed vaccine is currently available in the United States and treatment of tularemia is confined to few antibiotics. In this study, we demonstrate that AR-13, a derivative of the cyclooxygenase-2 inhibitor celecoxib, exhibits direct in vitro bactericidal killing activity against Francisella including a type A strain of F. tularensis (SchuS4) and the live vaccine strain (LVS), as well as toward the intracellular proliferation of LVS in macrophages, without causing significant host cell toxicity. Identification of an AR-13-resistant isolate indicates that this compound has an intracellular target(s) and that efflux pumps can mediate AR-13 resistance. In the mouse model of tularemia, AR-13 treatment protected 50% of the mice from lethal LVS infection and prolonged survival time from a lethal dose of F. tularensis SchuS4. Combination of AR-13 with a sub-optimal dose of gentamicin protected 60% of F. tularensis SchuS4-infected mice from death. Taken together, these data support the translational potential of AR-13 as a lead compound for the further development of new anti-Francisella agents.
Collapse
Affiliation(s)
- Ky V Hoang
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Haley E Adcox
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - James R Fitch
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States
| | - David M Gordon
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States
| | - Heather M Curry
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Larry S Schlesinger
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Peter White
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States.,Department of Pediatrics, The Ohio State University College of Medicine, ColumbusOH, United States
| | - John S Gunn
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| |
Collapse
|
45
|
Marecic V, Shevchuk O, Ozanic M, Mihelcic M, Steinert M, Jurak Begonja A, Abu Kwaik Y, Santic M. Isolation of F. novicida-Containing Phagosome from Infected Human Monocyte Derived Macrophages. Front Cell Infect Microbiol 2017; 7:303. [PMID: 28725638 PMCID: PMC5496951 DOI: 10.3389/fcimb.2017.00303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/20/2017] [Indexed: 11/28/2022] Open
Abstract
Francisella is a gram-negative bacterial pathogen, which causes tularemia in humans and animals. A crucial step of Francisella infection is its invasion of macrophage cells. Biogenesis of the Francisella-containing phagosome (FCP) is arrested for ~15 min at the endosomal stage, followed by gradual bacterial escape into the cytosol, where the microbe proliferates. The crucial step in pathogenesis of tularemia is short and transient presence of the bacterium within phagosome. Isolation of FCPs for further studies has been challenging due to the short period of time of bacterial residence in it and the characteristics of the FCP. Here, we will for the first time present the method for isolation of the FCPs from infected human monocytes-derived macrophages (hMDMs). For elimination of lysosomal compartment these organelles were pre-loaded with dextran coated colloidal iron particles prior infection and eliminated by magnetic separation of the post-nuclear supernatant (PNS). We encountered the challenge that mitochondria has similar density to the FCP. To separate the FCP in the PNS from mitochondria, we utilized iodophenylnitrophenyltetrazolium, which is converted by the mitochondrial succinate dehydrogenase into formazan, leading to increased density of the mitochondria and allowing separation by the discontinuous sucrose density gradient ultracentrifugation. The purity of the FCP preparation and its acquisition of early endosomal markers was confirmed by Western blots, confocal and transmission electron microscopy. Our strategy to isolate highly pure FCPs from macrophages should facilitate studies on the FCP and its biogenesis.
Collapse
Affiliation(s)
- Valentina Marecic
- Department of Microbiology and Parasitology, Faculty of Medicine, University of RijekaRijeka, Croatia
| | - Olga Shevchuk
- Department of Microbiology, Institut für Mikrobiologie, Technische Universität Braunschweig and Helmholtz Center for Infection ResearchBraunschweig, Germany.,Department of Biotechnology, University of RijekaRijeka, Croatia
| | - Mateja Ozanic
- Department of Microbiology and Parasitology, Faculty of Medicine, University of RijekaRijeka, Croatia
| | - Mirna Mihelcic
- Department of Microbiology and Parasitology, Faculty of Medicine, University of RijekaRijeka, Croatia
| | - Michael Steinert
- Department of Microbiology, Institut für Mikrobiologie, Technische Universität Braunschweig and Helmholtz Center for Infection ResearchBraunschweig, Germany
| | | | - Yousef Abu Kwaik
- Department of Microbiology and Immunology and Center for Predictive MedicineLouisville, KY, United States
| | - Marina Santic
- Department of Microbiology and Parasitology, Faculty of Medicine, University of RijekaRijeka, Croatia
| |
Collapse
|
46
|
Chen F, Rydzewski K, Kutzner E, Häuslein I, Schunder E, Wang X, Meighen-Berger K, Grunow R, Eisenreich W, Heuner K. Differential Substrate Usage and Metabolic Fluxes in Francisella tularensis Subspecies holarctica and Francisella novicida. Front Cell Infect Microbiol 2017; 7:275. [PMID: 28680859 PMCID: PMC5478678 DOI: 10.3389/fcimb.2017.00275] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/06/2017] [Indexed: 12/14/2022] Open
Abstract
Francisella tularensis is an intracellular pathogen for many animals causing the infectious disease, tularemia. Whereas F. tularensis subsp. holarctica is highly pathogenic for humans, F. novicida is almost avirulent for humans, but virulent for mice. In order to compare metabolic fluxes between these strains, we performed 13C-labeling experiments with F. tularensis subsp. holarctica wild type (beaver isolate), F. tularensis subsp. holarctica strain LVS, or F. novicida strain U112 in complex media containing either [U-13C6]glucose, [1,2-13C2]glucose, [U-13C3]serine, or [U-13C3]glycerol. GC/MS-based isotopolog profiling of amino acids, polysaccharide-derived glucose, free fructose, amino sugars derived from the cell wall, fatty acids, 3-hydroxybutyrate, lactate, succinate and malate revealed uptake and metabolic usage of all tracers under the experimental conditions with glucose being the major carbon source for all strains under study. The labeling patterns of the F. tularensis subsp. holarctica wild type were highly similar to those of the LVS strain, but showed remarkable differences to the labeling profiles of the metabolites from the F. novicida strain. Glucose was directly used for polysaccharide and cell wall biosynthesis with higher rates in F. tularensis subsp. holarctica or metabolized, with higher rates in F. novicida, via glycolysis and the non-oxidative pentose phosphate pathway (PPP). Catabolic turnover of glucose via gluconeogenesis was also observed. In all strains, Ala was mainly synthesized from pyruvate, although no pathway from pyruvate to Ala is annotated in the genomes of F. tularensis and F. novicida. Glycerol efficiently served as a gluconeogenetic substrate in F. novicida, but only less in the F. tularensis subsp. holarctica strains. In any of the studied strains, serine did not serve as a major substrate and was not significantly used for gluconeogenesis under the experimental conditions. Rather, it was only utilized, at low rates, in downstream metabolic processes, e.g., via acetyl-CoA in the citrate cycle and for fatty acid biosynthesis, especially in the F. tularensis subsp. holarctica strains. In summary, the data reflect differential metabolite fluxes in F. tularensis subsp. holarctica and F. novicida suggesting that the different utilization of substrates could be related to host specificity and virulence of Francisella.
Collapse
Affiliation(s)
- Fan Chen
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Kerstin Rydzewski
- Working Group "Cellular Interactions of Bacterial Pathogens", ZBS 2, Robert Koch InstituteBerlin, Germany
| | - Erika Kutzner
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Ina Häuslein
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Eva Schunder
- Working Group "Cellular Interactions of Bacterial Pathogens", ZBS 2, Robert Koch InstituteBerlin, Germany
| | - Xinzhe Wang
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Kevin Meighen-Berger
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Roland Grunow
- Centre for Biological Threats and Special Pathogens, Division 2 (ZBS 2), Highly Pathogenic Microorganisms, Robert Koch InstituteBerlin, Germany
| | - Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität MünchenGarching, Germany
| | - Klaus Heuner
- Working Group "Cellular Interactions of Bacterial Pathogens", ZBS 2, Robert Koch InstituteBerlin, Germany
| |
Collapse
|
47
|
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.
Collapse
Affiliation(s)
- Girija Ramakrishnan
- Department of Medicine/Division of Infectious Diseases, University of VirginiaCharlottesville, VA, USA
| |
Collapse
|
48
|
Ziveri J, Barel M, Charbit A. Importance of Metabolic Adaptations in Francisella Pathogenesis. Front Cell Infect Microbiol 2017; 7:96. [PMID: 28401066 PMCID: PMC5368251 DOI: 10.3389/fcimb.2017.00096] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/13/2017] [Indexed: 01/25/2023] Open
Abstract
Francisella tularensis is a highly infectious Gram-negative bacterium and the causative agent of the zoonotic disease tularemia. This bacterial pathogen can infect a broad variety of animal species and can be transmitted to humans in numerous ways with various clinical outcomes. Although, Francisella possesses the capacity to infect numerous mammalian cell types, the macrophage constitutes the main intracellular niche, used for in vivo bacterial dissemination. To survive and multiply within infected macrophages, Francisella must imperatively escape from the phagosomal compartment. In the cytosol, the bacterium needs to control the host innate immune response and adapt its metabolism to this nutrient-restricted niche. Our laboratory has shown that intracellular Francisella mainly relied on host amino acid as major gluconeogenic substrates and provided evidence that the host metabolism was also modified upon Francisella infection. We will review here our current understanding of how Francisella copes with the available nutrient sources provided by the host cell during the course of infection.
Collapse
Affiliation(s)
- Jason Ziveri
- Sorbonne Paris Cité, Université Paris DescartesParis, France; Institut National de la Santé et de la Recherche Médicale U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades, Team 11: Pathogenesis of Systemic InfectionsParis, France
| | - Monique Barel
- Sorbonne Paris Cité, Université Paris DescartesParis, France; Institut National de la Santé et de la Recherche Médicale U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades, Team 11: Pathogenesis of Systemic InfectionsParis, France
| | - Alain Charbit
- Sorbonne Paris Cité, Université Paris DescartesParis, France; Institut National de la Santé et de la Recherche Médicale U1151 - Centre National de la Recherche Scientifique UMR 8253, Institut Necker-Enfants Malades, Team 11: Pathogenesis of Systemic InfectionsParis, France
| |
Collapse
|
49
|
Powell DA, Frelinger JA. Efficacy of Resistance to Francisella Imparted by ITY/NRAMP/SLC11A1 Depends on Route of Infection. Front Immunol 2017; 8:206. [PMID: 28360906 PMCID: PMC5350118 DOI: 10.3389/fimmu.2017.00206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/15/2017] [Indexed: 11/13/2022] Open
Abstract
Natural resistance-associated macrophage protein (NRAMP) encoded by the Slc11a1 gene is a membrane-associated transporter of divalent metal ions. Murine Slc11a1 has two known alleles, a functional Slc11a1Gly169, which is found in DBA2/J, NOD/LtJ, and 129p3/J and related mouse strains, and a non-functional Slc11a1Asp169, that is found in C56Bl/6J (B6) and BALB/cJ mice. B6 mice congenic for Slc11a1Gly169 (B6-Slc11a1G169) are markedly resistant to the intracellular pathogens Salmonella, Leishmania, and Mycobacterium tuberculosis. We examined the host cell response and replication of Francisella in B6-Slc11a1G169 mice. Bone marrow-derived macrophages from either B6-Slc11a1G169 or B6 mice were both effectively invaded by Francisella live vaccine strain (LVS). However, at 16 hours post-infection (hpi), the number of LVS bacteria recovered from B6 macrophages had increased roughly 100-fold, while in B6-Slc11a1G169 mice the number decreased 10-fold. When the mice were challenged intranasally (i.n.) B6 mice lost significant amounts (~15%) of weight, where as B6-Slc11a1G169 mice lost no weight. Three days after infection in B6-Slc11a1G169 mice, we failed to recover viable Francisella from the lungs, livers, or spleens. By contrast, B6 mice had bacterial burdens approaching 1 × 106 CFU/organ in all three organs. To further examine the degree of resistance imparted by Slc11a1Gly169 expression, we challenged mice deficient in TLR2, TLR4, and TLR9, but expressing the functional Slc11a1 (B6-Slc11a1G169Tlr2/4/9−/−). Surprisingly, B6-Slc11a1G169Tlr2/4/9−/− mice had no notable weight loss. Eighty percent of B6-Slc11a1G169Tlr2/4/9−/− mice yielded no detectable Francisella in any organ tested. Additionally, Slc11a1G169 produced little detectable cytokine either in the lung or serum compared to B6 mice. Mice expressing Slc11a1Gly169 survived even high doses (~80 LD50) of LVS inoculation. These data taken together serve to highlight that functional Slc11a1Gly169 can compensate the lack of TLR2/4/9. Thus Slc11a1 is a critical player in murine resistance to pulmonary Francisella infection, but not footpad infection.
Collapse
Affiliation(s)
- Daniel A Powell
- Department of Immunobiology, University of Arizona , Tucson, AZ , USA
| | | |
Collapse
|
50
|
Bakkemo KR, Mikkelsen H, Johansen A, Robertsen B, Seppola M. Francisella noatunensis subsp. noatunensis invades, survives and replicates in Atlantic cod cells. DISEASES OF AQUATIC ORGANISMS 2016; 121:149-159. [PMID: 27667812 DOI: 10.3354/dao03043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Systemic infection caused by the facultative intracellular bacterium Francisella noatunensis subsp. noatunensis remains a disease threat to Atlantic cod Gadus morhua L. Future prophylactics could benefit from better knowledge on how the bacterium invades, survives and establishes infection in its host cells. Here, facilitated by the use of a gentamicin protection assay, this was studied in primary monocyte/macrophage cultures and an epithelial-like cell line derived from Atlantic cod larvae (ACL cells). The results showed that F. noatunensis subsp. noatunensis is able to invade primary monocyte/macrophages, and that the actin-polymerisation inhibitor cytochalasin D blocked internalisation, demonstrating that the invasion is mediated through phagocytosis. Interferon gamma (IFNγ) treatment of cod macrophages prior to infection enhanced bacterial invasion, potentially by stimulating macrophage activation in an early step in host defence against F. noatunensis subsp. noatunensis infections. We measured a rapid drop of the initial high levels of internalised bacteria in macrophages, indicating the presence and action of a cellular immune defence mechanism before intracellular bacterial replication took place. Low levels of bacterial internalisation and replication were detected in the epithelial-like ACL cells. The capacity of F. noatunensis subsp. noatunensis to enter, survive and even replicate within an epithelial cell line may play an important role in its ability to infect live fish and transverse epithelial barriers to reach the bacterium's main target cells-the macrophage.
Collapse
|