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Scheffzük C, Biedziak D, Gisch N, Goldmann T, Stamme C. Surfactant protein A modulates neuroinflammation in adult mice upon pulmonary infection. Brain Res 2024; 1840:149108. [PMID: 38964703 DOI: 10.1016/j.brainres.2024.149108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 06/17/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024]
Abstract
BACKGROUND One of the most common entry gates for systemic infection is the lung. In humans, pulmonary infections can lead to significant neurological impairment, ranging from acute sickness behavior to long-term disorders. Surfactant proteins (SP), essential parts of the pulmonary innate immune defense, have been detected in the brain of rats and humans. Recent evidence suggests that SP-A, the major protein component of surfactant, also plays a functional role in modulating neuroinflammation. This study aimed to determine whether SP-A deficiency affects the inflammatory response in the brain of adult mice during pulmonary infection. EXPERIMENTAL PROCEDURE Adult male wild-type (WT, n = 72) and SP-A-deficient (SP-A-/-, n = 72) mice were oropharyngeally challenged with lipopolysaccharide (LPS), Pseudomonas aeruginosa (P. aeruginosa), or PBS (control). Both, behavioral assessment and subsequent brain tissue analysis, were performed 24, 48, and 72 h after challenge. The brain concentrations of the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β were determined by ELISA. Quantitative rtPCR was used to detect SP-A mRNA expression in brain homogenates and immunohistochemistry was applied for the detection of SP-A protein expression in brain coronal slices. RESULTS SP-A mRNA and histological evidence of protein expression were detected in both the lungs and brains of WT mice, with significantly higher amounts in lung samples. SP-A-/- mice exhibited significantly higher baseline concentrations of brain TNF-α, IL-6, and IL-1β compared to WT mice. Oropharyngeal application of either LPS or P. aeruginosa elicited significantly higher brain levels of TNF-α and IL-1β in SP-A-/- mice compared to WT mice at all time points. In comparison, behavioral impairment as a measure of sickness behavior, was significantly stronger in WT than in SP-A-/- mice, particularly after LPS application. CONCLUSION SP-A is known for its anti-inflammatory role in the pulmonary immune response to bacterial infection. Recent evidence suggests that in an abdominal sepsis model SP-A deficiency can lead to increased cytokine levels in the brain. Our results extend this perception and provide evidence for an anti-inflammatory role of SP-A in the brain of adult WT mice after pulmonary infection.
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Affiliation(s)
- Claudia Scheffzük
- Division of Cellular Pneumology, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany; Department of Anesthesiology and Intensive Care Medicine, University Hospital of Schleswig-Holstein, Lübeck, Germany; Department of Anesthesiology and Intensive Care Medicine, University Hospital BG Bergmannsheil Bochum, Germany.
| | - Dominika Biedziak
- Division of Cellular Pneumology, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Torsten Goldmann
- Division of Histology, Research Center Borstel, Leibniz Lung Center, Borstel, Germany; Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Großhansdorf, Germany
| | - Cordula Stamme
- Division of Cellular Pneumology, Priority Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany; Department of Anesthesiology and Intensive Care Medicine, University Hospital of Schleswig-Holstein, Lübeck, Germany
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2
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Moustafa DA, Wu L, Ivey M, Fankhauser SC, Goldberg JB. Mutation of hmgA, encoding homogentisate 1,2-dioxygenase, is responsible for pyomelanin production but does not impact the virulence of Burkholderia cenocepacia in a chronic granulomatous disease mouse lung infection. Microbiol Spectr 2024; 12:e0041024. [PMID: 38809005 PMCID: PMC11218447 DOI: 10.1128/spectrum.00410-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/25/2024] [Indexed: 05/30/2024] Open
Abstract
The Burkholderia cepacia complex (Bcc) is a group of Gram-negative opportunistic bacteria often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis (CF) and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals; pigment production has been reported to enable Bcc strains to overcome the host cell oxidative burst. In this work, we investigated the role of pyomelanin in resistance to oxidative stress and virulence in strains J2315 and K56-2, two epidemic CF isolates belonging to the Burkholderia cenocepacia ET-12 lineage. We previously reported that a single amino acid change from glycine to arginine at residue 378 in homogentisate 1,2-dioxygenase (HmgA) affects the pigment production phenotype: pigmented J2315 has an arginine at position 378, while non-pigmented K56-2 has a glycine at this position. Herein, we performed allelic exchange to generate isogenic non-pigmented and pigmented strains of J2315 and K56-2, respectively, and tested these to determine whether pyomelanin contributes to the protection against oxidative stress in vitro as well as in a respiratory infection in CGD mice in vivo. Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist oxidative stress with H2O2 and NO in vitro and did not change the virulence and infection outcome in CGD mice in vivo suggesting that other factors besides pyomelanin are contributing to the pathophysiology of these strains.IMPORTANCEThe Burkholderia cepacia complex (Bcc) is a group of Gram-negative opportunistic bacteria that are often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals and overcoming the host cell oxidative burst. We investigated the role of pyomelanin in Burkholderia cenocepacia strains J2315 (pigmented) and K56-2 (non-pigmented) and performed allelic exchange to generate isogenic non-pigmented and pigmented strains, respectively. Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist H2O2 or NO in vitro and did not alter the outcome of a respiratory infection in CGD mice in vivo. These results suggest that pyomelanin may not always constitute a virulence factor and suggest that other features are contributing to the pathophysiology of these strains.
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Affiliation(s)
- Dina A Moustafa
- Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Linda Wu
- Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Melissa Ivey
- Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sarah C Fankhauser
- Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Biology, Oxford College of Emory University, Oxford, Georgia, USA
| | - Joanna B Goldberg
- Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
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Rinderknecht CH, Ning M, Wu C, Wilson MS, Gampe C. Designing inhaled small molecule drugs for severe respiratory diseases: an overview of the challenges and opportunities. Expert Opin Drug Discov 2024; 19:493-506. [PMID: 38407117 DOI: 10.1080/17460441.2024.2319049] [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: 11/27/2023] [Accepted: 02/12/2024] [Indexed: 02/27/2024]
Abstract
INTRODUCTION Inhaled drugs offer advantages for the treatment of respiratory diseases over oral drugs by delivering the drug directly to the lung, thus improving the therapeutic index. There is an unmet medical need for novel therapies for lung diseases, exacerbated by a multitude of challenges for the design of inhaled small molecule drugs. AREAS COVERED The authors review the challenges and opportunities for the design of inhaled drugs for respiratory diseases with a focus on new target discovery, medicinal chemistry, and pharmacokinetic, pharmacodynamic, and toxicological evaluation of drug candidates. EXPERT OPINION Inhaled drug discovery is facing multiple unique challenges. Novel biological targets are scarce, as is the guidance for medicinal chemistry teams to design compounds with inhalation-compatible features. It is exceedingly difficult to establish a PK/PD relationship given the complexity of pulmonary PK and the impact of physical properties of the drug substance on PK. PK, PD and toxicology studies are technically challenging and require large amounts of drug substance. Despite the current challenges, the authors foresee that the design of inhaled drugs will be facilitated in the future by our increasing understanding of pathobiology, emerging medicinal chemistry guidelines, advances in drug formulation, PBPK models, and in vitro toxicology assays.
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Affiliation(s)
| | - Miaoran Ning
- Drug Metabolism and Pharmacokinetics, gRED, Genentech, South San Francisco, CA, USA
| | - Connie Wu
- Development Sciences Safety Assessment, Genentech, South San Francisco, CA, USA
| | - Mark S Wilson
- Discovery Immunology, gRED, Genentech, South San Francisco, CA, USA
| | - Christian Gampe
- Discovery Chemistry, gRED, Genentech, South San Francisco, CA, USA
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4
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Grandy S, Scur M, Dolan K, Nickerson R, Cheng Z. Using model systems to unravel host-Pseudomonas aeruginosa interactions. Environ Microbiol 2023; 25:1765-1784. [PMID: 37290773 DOI: 10.1111/1462-2920.16440] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/29/2023] [Indexed: 06/10/2023]
Abstract
Using model systems in infection biology has led to the discoveries of many pathogen-encoded virulence factors and critical host immune factors to fight pathogenic infections. Studies of the remarkable Pseudomonas aeruginosa bacterium that infects and causes disease in hosts as divergent as humans and plants afford unique opportunities to shed new light on virulence strategies and host defence mechanisms. One of the rationales for using model systems as a discovery tool to characterise bacterial factors driving human infection outcomes is that many P. aeruginosa virulence factors are required for pathogenesis in diverse different hosts. On the other side, many host signalling components, such as the evolutionarily conserved mitogen-activated protein kinases, are involved in immune signalling in a diverse range of hosts. Some model organisms that have less complex immune systems also allow dissection of the direct impacts of innate immunity on host defence without the interference of adaptive immunity. In this review, we start with discussing the occurrence of P. aeruginosa in the environment and the ability of this bacterium to cause disease in various hosts as a natural opportunistic pathogen. We then summarise the use of some model systems to study host defence and P. aeruginosa virulence.
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Affiliation(s)
- Shannen Grandy
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michal Scur
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kathleen Dolan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Rhea Nickerson
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Zhenyu Cheng
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
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5
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Nanayakkara AK, Moustafa DA, Pifer R, Goldberg JB, Greenberg DE. Sequence specificity defines the effectiveness of PPMOs targeting Pseudomonas aeruginosa. Antimicrob Agents Chemother 2023; 67:e0024523. [PMID: 37610213 PMCID: PMC10508178 DOI: 10.1128/aac.00245-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 06/18/2023] [Indexed: 08/24/2023] Open
Abstract
Development of new therapeutics against antibiotic resistant pathogenic bacteria is recognized as a priority across the globe. We have reported using peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs) as species-specific antibiotics. The oligo sequences, 11 bases are designed to be complementary to specific essential genes near the Shine-Dalgarno site and inhibit translation. Here, we analyzed target specificity and the impact of genetic mutations on lead PPMOs targeting the rpsJ or acpP gene of Pseudomonas aeruginosa. Mutants in P. aeruginosa PAO1 were generated with four, two, or one base-pair mutations within the 11-base target sequence of the rpsJ gene. All mutants exhibited increased MICs compared to wild-type PAO1 when treated with the RpsJ PPMO, and the increase in the MICs was proportional to the number of base-pair mutations. Among single base-pair mutants, mutations in the middle of the sequence were more impactful than mutations in 5' or 3' end of the sequence. The increased MICs shown by the rpsJ mutants could be reversed by PPMOs designed to target the mutated rpsJ sequence. BALB/c mice infected intratracheally with mutants demonstrated increased lung burden when treated with RpsJ PPMO compared to wild-type PAO1-infected mice treated with RpsJ PPMO. Treating mice with a PPMOs designed to specifically target the mutant sequence was more effective against these mutant strains. These experiments confirm target specificity of two lead P. aeruginosa PPMOs and illustrate one potential mechanism of resistance that could emerge from an antisense approach.
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Affiliation(s)
- A. K. Nanayakkara
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - D. A. Moustafa
- Department of Pediatrics and Children’s Healthcare of Atlanta, Center for Cystic Fibrosis and Airway Diseases Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - R. Pifer
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - J. B. Goldberg
- Department of Pediatrics and Children’s Healthcare of Atlanta, Center for Cystic Fibrosis and Airway Diseases Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - D. E. Greenberg
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Alonso Paiva IM, A. Santos R, Brito CB, Ferrero MC, Ortiz Wilczyñski JM, Silva EAC, C. Oliveira S, Baldi PC. Role of the cGAS/STING pathway in the control of Brucella abortus infection acquired through the respiratory route. Front Immunol 2023; 14:1116811. [PMID: 37261352 PMCID: PMC10227575 DOI: 10.3389/fimmu.2023.1116811] [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: 12/05/2022] [Accepted: 04/28/2023] [Indexed: 06/02/2023] Open
Abstract
Despite the importance of the respiratory route for Brucella transmission, the lung immune response to this pathogen is scarcely characterized. We investigated the role of the cGAS/STING pathway of microbial DNA recognition in the control of respiratory Brucella infection. After in vitro B. abortus infection, CFU numbers were significantly higher in alveolar macrophages (AM) and lung explants from STING KO mice than in samples from wild type (WT) mice, but no difference was observed for cGAS KO samples. CFU were also increased in WT AM and lung epithelial cells preincubated with the STING inhibitor H151. Several proinflammatory cytokines (TNF-α, IL-1β, IL-6, IP-10/CXCL10) were diminished in Brucella-infected lung explants and/or AM from STING KO mice and cGAS KO mice. These cytokines were also reduced in infected AM and lung epithelial cells pretreated with H151. After intratracheal infection with B. abortus, STING KO mice exhibited increased CFU in lungs, spleen and liver, a reduced expression of IFN-β mRNA in lungs and spleen, and reduced levels of proinflammatory cytokines and chemokines in bronchoalveolar lavage fluid (BALF) and lung homogenates. Increased lung CFU and reduced BALF cytokines were also observed in cGAS KO mice. In summary, the cGAS/STING pathway induces the production of proinflammatory cytokines after respiratory Brucella infection, which may contribute to the STING-dependent control of airborne brucellosis.
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Affiliation(s)
- Iván M. Alonso Paiva
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Raiany A. Santos
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Camila B. Brito
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mariana C. Ferrero
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Juan Manuel Ortiz Wilczyñski
- Laboratorio de Trombosis Experimental, Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Eugenio A. Carrera Silva
- Laboratorio de Trombosis Experimental, Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Sergio C. Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Pablo C. Baldi
- Cátedra de Inmunología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
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7
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Sato K, Kawakami K. Mouse Model of Latent Cryptococcal Infection and Reactivation. Methods Mol Biol 2023; 2667:87-98. [PMID: 37145277 DOI: 10.1007/978-1-0716-3199-7_6] [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: 05/06/2023]
Abstract
AbstractCryptococcus neoformans is an opportunistic fungal pathogen that frequently causes fatal meningoencephalitis in patients with impaired immune responses. This fungus, an intracellularly growing microbe, evades host immunity, leading to a latent infection (latent C. neoformans infection: LCNI), and cryptococcal disease is developed by its reactivation when host immunity is suppressed. Elucidation of the pathophysiology of LCNI is difficult due to the lack of mouse models. Here we show the established methods for LCNI and reactivation.
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Affiliation(s)
- Ko Sato
- Department of Medical Microbiology, Mycology and Immunology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
- Department of Intelligent Network for Infection Control, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
| | - Kazuyoshi Kawakami
- Department of Medical Microbiology, Mycology and Immunology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Intelligent Network for Infection Control, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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Taylor IR, Jeffrey PD, Moustafa DA, Goldberg JB, Bassler BL. The PqsE Active Site as a Target for Small Molecule Antimicrobial Agents against Pseudomonas aeruginosa. Biochemistry 2022; 61:1894-1903. [PMID: 35985643 PMCID: PMC9454246 DOI: 10.1021/acs.biochem.2c00334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
The opportunistic pathogen Pseudomonas
aeruginosa causes antibiotic-resistant, nosocomial
infections in immuno-compromised
individuals and is a high priority for antimicrobial development.
Key to pathogenicity in P. aeruginosa are biofilm formation and virulence factor production. Both traits
are controlled by the cell-to-cell communication process called quorum
sensing (QS). QS involves the synthesis, release, and population-wide
detection of signal molecules called autoinducers. We previously reported
that the activity of the RhlR QS transcription factor depends on a
protein–protein interaction with the hydrolase, PqsE, and PqsE
catalytic activity is dispensable for this interaction. Nonetheless,
the PqsE–RhlR interaction could be disrupted by the substitution
of an active site glutamate residue with tryptophan [PqsE(E182W)].
Here, we show that disruption of the PqsE–RhlR interaction
via either the E182W change or alteration of PqsE surface residues
that are essential for the interaction with RhlR attenuates P. aeruginosa infection in a murine host. We use
crystallography to characterize the conformational changes induced
by the PqsE(E182W) substitution to define the mechanism underlying
disruption of the PqsE–RhlR interaction. A loop rearrangement
that repositions the E280 residue in PqsE(E182W) is responsible for
the loss of interaction. We verify the implications garnered from
the PqsE(E182W) structure using mutagenic, biochemical, and additional
structural analyses. We present the next generation of molecules targeting
the PqsE active site, including a structure of the tightest binding
of these compounds, BB584, in complex with PqsE. The findings presented
here provide insights into drug discovery against P.
aeruginosa with PqsE as the target.
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Affiliation(s)
- Isabelle R Taylor
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
| | - Dina A Moustafa
- School of Medicine, Children's Healthcare of Atlanta, Inc., Department of Pediatrics, and Center for Cystic Fibrosis and Airway Diseases Research, Emory University, Atlanta, Georgia 30322, United States
| | - Joanna B Goldberg
- School of Medicine, Children's Healthcare of Atlanta, Inc., Department of Pediatrics, and Center for Cystic Fibrosis and Airway Diseases Research, Emory University, Atlanta, Georgia 30322, United States
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, United States
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Guasconi L, Beccacece I, Volpini X, Burstein VL, Mena CJ, Silvane L, Almeida MA, Musri MM, Cervi L, Chiapello LS. Pulmonary Conventional Type 1 Langerin-Expressing Dendritic Cells Play a Role in Impairing Early Protective Immune Response against Cryptococcus neoformans Infection in Mice. J Fungi (Basel) 2022; 8:jof8080792. [PMID: 36012781 PMCID: PMC9410147 DOI: 10.3390/jof8080792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/21/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022] Open
Abstract
Lung dendritic cells (DC) are powerful antigen-presenting cells constituted by various subpopulations that differ in terms of their function and origin and differentially regulate cell-mediated antifungal immunity. The lung is the primary target organ of Cryptococcus neoformans and C. gattii infections, which makes it essential in the establishment of the first line of anti-cryptococcal defense. However, the lung-specific dynamics and function of DC subsets are poorly understood in cryptococcosis. In this study, we provide evidence for the in vivo function of a conventional langerin-expressing DC1 dendritic cell (LangDC1) population during the first week of intratracheal C. neoformans infection in mice. By using conditional depletion of LangDC1 after diphtheria toxin treatment of LangDTREGFP mice, we demonstrate that these animals better control the fungal infection and produce type 1 and 17 cytokines in the context of a type 2 immune response, favoring a predominance of iNOS over arginase-1 expression by pulmonary cells. Our results suggest that LangDC1 cells play a role in impairing immune response for the clearance of C. neoformans in the early stage of pulmonary infection.
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Affiliation(s)
- Lorena Guasconi
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Ignacio Beccacece
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Ximena Volpini
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5016GCA, Argentina;
| | - Verónica L. Burstein
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Cristian J. Mena
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Leonardo Silvane
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Mariel A. Almeida
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
| | - Melina Mara Musri
- Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5016GCA, Argentina;
- Departamento de Fisiología, Facultad de Ciencias Exactas, Físicas y Naturales (FCEFyN), Universidad Nacional de Córdoba, Córdoba X5016GCA, Argentina
| | - Laura Cervi
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
- Correspondence: (L.C.); (L.S.C.)
| | - Laura S. Chiapello
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina; (L.G.); (I.B.); (X.V.); (V.L.B.); (C.J.M.); (L.S.); (M.A.A.)
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba X5000HUA, Argentina
- Correspondence: (L.C.); (L.S.C.)
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10
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Yang MS, Park MJ, Lee J, Oh B, Kang KW, Kim Y, Lee SM, Lim JO, Jung TY, Park JH, Park SC, Lim YS, Hwang SB, Lyoo KS, Kim DI, Kim B. Non-invasive administration of AAV to target lung parenchymal cells and develop SARS-CoV-2-susceptible mice. Mol Ther 2022; 30:1994-2004. [PMID: 35007757 PMCID: PMC8739362 DOI: 10.1016/j.ymthe.2022.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/28/2021] [Accepted: 01/05/2022] [Indexed: 12/19/2022] Open
Abstract
Adeno-associated virus (AAV)-mediated gene delivery holds great promise for gene therapy. However, the non-invasive delivery of AAV for lung tissues has not been adequately established. Here, we revealed that the intratracheal administration of an appropriate amount of AAV2/8 predominantly targets lung tissue. AAV-mediated gene delivery that we used in this study induced the expression of the desired protein in lung parenchymal cells, including alveolar type II cells. We harnessed the technique to develop severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-susceptible mice. Three kinds of immune function-relevant gene knockout (KO) mice were transduced with AAV encoding human angiotensin-converting enzyme 2 (hACE2) and then injected with SARS-CoV-2. Among these mice, type I interferon receptor (IFNAR) KO mice showed increased viral titer in the lungs compared to that in the other KO mice. Moreover, nucleocapsid protein of SARS-CoV-2 and multiple lesions in the trachea and lung were observed in AAV-hACE2-transduced, SARS-CoV-2-infected IFNAR KO mice, indicating the involvement of type I interferon signaling in the protection of SARS-CoV-2. In this study, we demonstrate the ease and rapidness of the intratracheal administration of AAV for targeting lung tissue in mice, and this can be used to study diverse pulmonary diseases.
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Affiliation(s)
- Myeon-Sik Yang
- Biosafety Research Institute and Laboratory of Veterinary Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Min-Jung Park
- Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea; College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea
| | - Junhyeong Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea; College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea
| | - Byungkwan Oh
- Biosafety Research Institute and Laboratory of Veterinary Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Kyung Won Kang
- Division of Biotechnology, College of Environmental and Bioresources, Jeonbuk National University, Iksan 54596, Korea
| | - Yeonhwa Kim
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
| | - Sang-Myeong Lee
- College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea
| | - Je-Oh Lim
- College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea
| | - Tae-Yang Jung
- College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea
| | - Jong-Hwan Park
- College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea; Laboratory Animal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea
| | - Seok-Chan Park
- Biosafety Research Institute and Laboratory of Veterinary Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea
| | - Yun-Sook Lim
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Korea
| | - Soon B Hwang
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Korea
| | - Kwang-Soo Lyoo
- Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Korea
| | - Dong-Il Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea; College of Veterinary Medicine and BK21 FOUR Program, Chonnam National University, Gwangju 61186, Korea.
| | - Bumseok Kim
- Biosafety Research Institute and Laboratory of Veterinary Pathology, College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Korea; Korea Zoonosis Research Institute, Jeonbuk National University, Iksan 54531, Korea.
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11
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Resendiz-Sharpe A, da Silva RP, Geib E, Vanderbeke L, Seldeslachts L, Hupko C, Brock M, Lagrou K, Vande Velde G. Longitudinal multimodal imaging-compatible mouse model of triazole-sensitive and -resistant invasive pulmonary aspergillosis. Dis Model Mech 2022; 15:274857. [PMID: 35352801 PMCID: PMC8990085 DOI: 10.1242/dmm.049165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 01/09/2022] [Indexed: 12/18/2022] Open
Abstract
Invasive pulmonary aspergillosis (IPA) caused by the mold Aspergillus fumigatus is one of the most important life-threatening infections in immunocompromised patients. The alarming increase of isolates resistant to the first-line recommended antifungal therapy urges more insights into triazole-resistant A. fumigatus infections. In this study, we systematically optimized a longitudinal multimodal imaging-compatible neutropenic mouse model of IPA. Reproducible rates of pulmonary infection were achieved through immunosuppression (sustained neutropenia) with 150 mg/kg cyclophosphamide at day −4, −1 and 2, and an orotracheal inoculation route in both sexes. Furthermore, increased sensitivity of in vivo bioluminescence imaging for fungal burden detection, as early as the day after infection, was achieved by optimizing luciferin dosing and through engineering isogenic red-shifted bioluminescent A. fumigatus strains, one wild type and two triazole-resistant mutants. We successfully tested appropriate and inappropriate antifungal treatment scenarios in vivo with our optimized multimodal imaging strategy, according to the in vitro susceptibility of our luminescent fungal strains. Therefore, we provide novel essential mouse models with sensitive imaging tools for investigating IPA development and therapy in triazole-susceptible and triazole-resistant scenarios. Summary: A novel reproducible longitudinal multimodal imaging-compatible neutropenic mouse model of invasive pulmonary aspergillosis provides increased early fungal detection through novel red-shifted luciferase-expressing triazole-susceptible and -resistant Aspergillus fumigatus strains, and boosted bioluminescence.
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Affiliation(s)
- Agustin Resendiz-Sharpe
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Roberta Peres da Silva
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Geib
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Lore Vanderbeke
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Laura Seldeslachts
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
| | - Charlien Hupko
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Katrien Lagrou
- Laboratory of Clinical Microbiology, Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit (KU) Leuven, 3000 Leuven, Belgium.,Department of Laboratory Medicine and National Reference Centre for Mycosis, Excellence Centre for Medical Mycology (ECMM), University Hospitals Leuven, 3000 Leuven, Belgium
| | - Greetje Vande Velde
- Department of Imaging and Pathology, Biomedical MRI unit/MoSAIC, KU Leuven, 3000 Leuven, Belgium
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12
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García-Reyes S, Moustafa DA, Attrée I, Goldberg JB, Quiroz-Morales SE, Soberón-Chávez G. Vfr or CyaB promote the expression of the pore-forming toxin exlBA operon in Pseudomonas aeruginosa ATCC 9027 without increasing its virulence in mice. MICROBIOLOGY-SGM 2021; 167. [PMID: 34424157 DOI: 10.1099/mic.0.001083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pseudomonas aeruginosa is a wide-spread γ-proteobacterium that produces the biosurfactant rhamnolipid that has a great commercial value due to excellent properties of low toxicity and high biodegradability. However, this bacterium is an opportunist pathogen that constitutes an important health hazard due to its production of virulence-associated traits and its high antibiotic resistance. Thus, it is highly desirable to have a non-virulent P. aeruginosa strain for rhamnolipid production. It has been reported that strain ATCC 9027 is avirulent in mouse models of infection, and it is still able to produce rhamnolipid. Thus, it has been proposed to be suitable for it industrial production, since it encodes a defective LasR quorum sensing (QS) transcriptional regulator that is the head of this regulatory network. However, the restoration of virulence factor production by overexpression of rhlR (the gene encoding a QS-transcriptional regulator which is under the transcriptional control of LasR) is not sufficient to restore its virulence in mice. It is desirable to obtain a deeper understanding of ATCC 9027 attenuated-virulence phenotype and to assess the safety of this strain to be used at an industrial scale. In this work we determined whether increasing the expression of the pore-forming toxin encoded by the exlBA operon in strain ATCC 9027 had an impact on its virulence using Galleria mellonella and mouse models of infections. We increased the expression of the exlBA operon by overexpressing from a plasmid its transcriptional activator Vfr or of the Vfr ligand cyclic AMP produced by CyaB. We found that in G. mellonella ATCC 9027/pUCP24-vfr and ATCC 9027/pUCP24-cyaB gained a virulent phenotype, but these strains remained avirulent in murine models of P. aeruginosa infection. These results reinforce the possibility of using ATCC 9027 for industrial biosurfactants production.
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Affiliation(s)
- Selene García-Reyes
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
| | - Dina A Moustafa
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA.,Emory Children's Centre for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ina Attrée
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, Grenoble, France
| | - Joanna B Goldberg
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA.,Emory Children's Centre for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sara E Quiroz-Morales
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
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13
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Peptide-Conjugated Phosphorodiamidate Morpholino Oligomers Retain Activity against Multidrug-Resistant Pseudomonas aeruginosa In Vitro and In Vivo. mBio 2021; 12:mBio.02411-20. [PMID: 33436433 PMCID: PMC7844538 DOI: 10.1128/mbio.02411-20] [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] [Indexed: 12/15/2022] Open
Abstract
Numerous Gram-negative bacteria are becoming increasingly resistant to multiple, if not all, classes of existing antibiotics. Multidrug-resistant Pseudomonas aeruginosa bacteria are a major cause of health care-associated infections in a variety of clinical settings, endangering patients who are immunocompromised or those who suffer from chronic infections, such as people with cystic fibrosis (CF). Most antimicrobials currently in the clinical pipeline are modifications of existing classes of antibiotics and are considered short-term solutions due to the emergence of resistance. Pseudomonas aeruginosa represents a major challenge for new antimicrobial drug discovery due to its versatile lifestyle, ability to develop resistance to most antibiotic classes, and capacity to form robust biofilms on surfaces and in certain hosts such as those living with cystic fibrosis (CF). A precision antibiotic approach to treating Pseudomonas could be achieved with an antisense method, specifically by using peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs). Here, we demonstrate that PPMOs targeting acpP (acyl carrier protein), lpxC (UDP-(3-O-acyl)-N-acetylglucosamine deacetylase), and rpsJ (30S ribosomal protein S10) inhibited the in vitro growth of several multidrug-resistant clinical P. aeruginosa isolates at levels equivalent to those that were effective against sensitive strains. Lead PPMOs reduced established pseudomonal biofilms alone or in combination with tobramycin or piperacillin-tazobactam. Lead PPMO dosing alone or combined with tobramycin in an acute pneumonia model reduced lung bacterial burden in treated mice at 24 h and reduced morbidity up to 5 days postinfection. PPMOs reduced bacterial burden of extensively drug-resistant P. aeruginosa in the same model and resulted in superior survival compared to conventional antibiotics. These data suggest that lead PPMOs alone or in combination with clinically relevant antibiotics represent a promising therapeutic approach for combating P. aeruginosa infections.
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14
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Morelli MP, Del Medico Zajac MP, Pellegrini JM, Amiano NO, Tateosian NL, Calamante G, Gherardi MM, García VE. IL-12 DNA Displays Efficient Adjuvant Effects Improving Immunogenicity of Ag85A in DNA Prime/MVA Boost Immunizations. Front Cell Infect Microbiol 2020; 10:581812. [PMID: 33072631 PMCID: PMC7538621 DOI: 10.3389/fcimb.2020.581812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/18/2020] [Indexed: 01/26/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) infection is one of the leading causes of death worldwide. The Modified Vaccinia Ankara (MVA) vaccine vector expressing the mycobacterial antigen 85A (MVA85A) was demonstrated to be safe, although it did not improve BCG efficacy, denoting the need to search for improved tuberculosis vaccines. In this work, we investigated the effect of IL-12 DNA -as an adjuvant- on an Ag85A DNA prime/MVA85A boost vaccination regimen. We evaluated the immune response profile elicited in mice and the protection conferred against intratracheal Mtb H37Rv challenge. We observed that the immunization scheme including DNA-A85A+DNA-IL-12/MVA85A induced a strong IFN-γ production to Ag85A in vitro, with a significant expansion of IFN-γ+CD4+ and IFN-γ+CD8+ anti-Ag85A lymphocytes. Furthermore, we also detected a significant increase in the proportion of specific CD8+CD107+ T cells against Ag85A. Additionally, inclusion of IL-12 DNA in the DNA-A85A/MVA85A vaccine scheme induced a marked augment in anti-Ag85A IgG levels. Interestingly, after 30 days of infection with Mtb H37Rv, DNA-A85A+DNA-IL-12/MVA85A vaccinated mice displayed a significant reduction in lung bacterial burden. Together, our findings suggest that IL-12 DNA might be useful as a molecular adjuvant in an Ag85A DNA/MVA prime-boost vaccine against Mtb infection.
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Affiliation(s)
- María Paula Morelli
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Paula Del Medico Zajac
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Joaquín Miguel Pellegrini
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nicolás Oscar Amiano
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nancy Liliana Tateosian
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gabriela Calamante
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - María Magdalena Gherardi
- Instituto de Investigaciones Biomédicas en Retrovirus y SIDA (INBIRS), Facultad de Medicina, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Verónica Edith García
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires (UBA)-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales (FCEN), Universidad de Buenos Aires, Buenos Aires, Argentina
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15
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Role of Pseudomonas aeruginosa Glutathione Biosynthesis in Lung and Soft Tissue Infection. Infect Immun 2020; 88:IAI.00116-20. [PMID: 32284368 DOI: 10.1128/iai.00116-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/05/2020] [Indexed: 01/21/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa is a leading cause of morbidity and mortality worldwide. To survive in both the environment and the host, P. aeruginosa must cope with redox stress. In P. aeruginosa, a primary mechanism for protection from redox stress is the antioxidant glutathione (GSH). GSH is a low-molecular-weight thiol-containing tripeptide (l-γ-glutamyl-l-cysteinyl-glycine) that can function as a reversible reducing agent. GSH plays an important role in P. aeruginosa physiology and is known to modulate several cellular and social processes that are likely important during infection. However, the role of GSH biosynthesis during mammalian infection is not well understood. In this study, we created a P. aeruginosa mutant defective in GSH biosynthesis to examine how loss of GSH biosynthesis affects P. aeruginosa virulence. We found that GSH is critical for normal growth in vitro and provides protection against hydrogen peroxide, bleach, and ciprofloxacin. We also studied the role of P. aeruginosa GSH biosynthesis in four mouse infection models, including the surgical wound, abscess, burn wound, and acute pneumonia models. We discovered that the GSH biosynthesis mutant was slightly less virulent in the acute pneumonia infection model but was equally virulent in the three other models. This work provides new and complementary data regarding the role of GSH in P. aeruginosa during mammalian infection.
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16
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Hielpos MS, Fernández AG, Falivene J, Alonso Paiva IM, Muñoz González F, Ferrero MC, Campos PC, Vieira AT, Oliveira SC, Baldi PC. IL-1R and Inflammasomes Mediate Early Pulmonary Protective Mechanisms in Respiratory Brucella Abortus Infection. Front Cell Infect Microbiol 2018; 8:391. [PMID: 30456207 PMCID: PMC6231193 DOI: 10.3389/fcimb.2018.00391] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/17/2018] [Indexed: 12/19/2022] Open
Abstract
Brucella spp. infection is frequently acquired through contaminated aerosols. The role of interleukin-1 beta (IL-1β) in the early pulmonary response to respiratory Brucella infection is unknown. As shown here, IL-1β levels in lung homogenates and bronchoalveolar lavage fluid (BALF) of mice intratracheally inoculated with B. abortus were increased at 3 and 7 days p.i. At 7 days p.i., pulmonary CFU numbers were higher in IL-1 receptor (IL-1R) knockout (KO) mice than in wild type (WT) mice. At different times p.i. CFU in lungs and BALF were higher in mice lacking some inflammasome components (caspase-1, AIM2, NLRP3) than in WT mice. At 2 days p.i. pulmonary levels of IL-1β and CXCL1 (neutrophils chemoattractant) were lower in caspase-1/11 KO mice. At day 3 p.i., neutrophils counts in BALF were lower in caspase-1/11 KO mice than in WT mice. During in vitro infections, IL-1β secretion was lower in alveolar macrophages from caspase-1/11, NLRP3 or AIM2 KO mice than in WT controls. Similarly, IL-1β production by B. abortus-infected alveolar epithelial cells was reduced by pretreatment with a specific caspase-1 inhibitor. This study shows that IL-1R, probably through IL-1β action, and the NLRP3 and AIM2 inflammasomes are involved in pulmonary innate immune protective mechanisms against respiratory B. abortus infection.
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Affiliation(s)
- M Soledad Hielpos
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Andrea G Fernández
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Juliana Falivene
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Iván M Alonso Paiva
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Florencia Muñoz González
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Mariana C Ferrero
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
| | - Priscila C Campos
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Angelica T Vieira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Sergio Costa Oliveira
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Pablo C Baldi
- Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral, Buenos Aires, Argentina
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17
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Hielpos MS, Ferrero MC, Fernández AG, Falivene J, Vanzulli S, Comerci DJ, Baldi PC. Btp Proteins from Brucella abortus Modulate the Lung Innate Immune Response to Infection by the Respiratory Route. Front Immunol 2017; 8:1011. [PMID: 28970827 PMCID: PMC5609629 DOI: 10.3389/fimmu.2017.01011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/07/2017] [Indexed: 01/18/2023] Open
Abstract
Although inhalation of infected aerosols is a frequent route for Brucella infection in humans, it rarely causes pulmonary clinical manifestations, suggesting a mild or nearly absent local inflammatory response. The goal of this study was to characterize the early innate immune response to intratracheal infection with Brucella abortus in mice and to evaluate whether it is modulated by this pathogen. After infection with 106 CFU of B. abortus, the pulmonary bacterial burden at 7 days post-infection (p.i.) was comparable to the initial inoculum, despite an initial transient decline. Brucella was detected in spleen and liver as early as 1 day p.i. IL-1β and MCP-1 increased at 3 days p.i., whereas IL-12, KC, TNF-α, and IFN-γ only increased at 7 days p.i. Histological examination did not reveal peribronchial or perivascular infiltrates in infected mice. Experiments were conducted to evaluate if the limited inflammatory lung response to B. abortusis caused by a bacterial mechanism of TLR signaling inhibition. Whereas inoculation of E. coli LPS to control mice [phosphate-buffered saline (PBS)/LPS] caused lung inflammation, almost no histological changes were observed in mice preinfected intratracheally with B. abortus (WT/LPS). We speculated that the Brucella TIR-containing proteins (Btps) A and B, which impair TLR signaling in vitro, may be involved in this modulation. After LPS challenge, mice preinfected with the B. abortus btpAbtpB double mutant exhibited a stronger pulmonary polymorphonuclear infiltrate than WT/LPS mice, although milder than that of the PBS/LPS group. In addition, lungs from B. abortus btpAbtpB-infected mice presented a stronger inflammatory infiltrate than those infected with the WT strain, and at day 7 p.i., the pulmonary levels of KC, MCP-1, and IL-12 were higher in mice infected with the mutant. This study shows that B. abortus infection produces a mild proinflammatory response in murine lungs, partially due to immune modulation by its Btp proteins. This may facilitate its survival and dissemination to peripheral organs.
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Affiliation(s)
- Maria Soledad Hielpos
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina
| | - Mariana C Ferrero
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina
| | - Andrea G Fernández
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina
| | - Juliana Falivene
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina
| | - Silvia Vanzulli
- Laboratorio de Anatomía Patológica, Instituto de Estudios Oncológicos, Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Diego J Comerci
- Instituto de Investigaciones Biotecnológicas (IIB, UNSAM-CONICET), San Martín, Argentina
| | - Pablo C Baldi
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Inmunología, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina
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18
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Mukherjee S, Moustafa D, Smith CD, Goldberg JB, Bassler BL. The RhlR quorum-sensing receptor controls Pseudomonas aeruginosa pathogenesis and biofilm development independently of its canonical homoserine lactone autoinducer. PLoS Pathog 2017; 13:e1006504. [PMID: 28715477 PMCID: PMC5531660 DOI: 10.1371/journal.ppat.1006504] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/27/2017] [Accepted: 07/01/2017] [Indexed: 12/22/2022] Open
Abstract
Quorum sensing (QS) is a bacterial cell-to-cell communication process that relies on the production, release, and response to extracellular signaling molecules called autoinducers. QS controls virulence and biofilm formation in the human pathogen Pseudomonas aeruginosa. P. aeruginosa possesses two canonical LuxI/R-type QS systems, LasI/R and RhlI/R, which produce and detect 3OC12-homoserine lactone and C4-homoserine lactone, respectively. Here, we use biofilm analyses, reporter assays, RNA-seq studies, and animal infection assays to show that RhlR directs both RhlI-dependent and RhlI-independent regulons. In the absence of RhlI, RhlR controls the expression of genes required for biofilm formation as well as genes encoding virulence factors. Consistent with these findings, ΔrhlR and ΔrhlI mutants have radically different biofilm phenotypes and the ΔrhlI mutant displays full virulence in animals whereas the ΔrhlR mutant is attenuated. The ΔrhlI mutant cell-free culture fluids contain an activity that stimulates RhlR-dependent gene expression. We propose a model in which RhlR responds to an alternative ligand, in addition to its canonical C4-homoserine lactone autoinducer. This alternate ligand promotes a RhlR-dependent transcriptional program in the absence of RhlI.
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Affiliation(s)
- Sampriti Mukherjee
- Princeton University, Department of Molecular Biology, Princeton, NJ, United States of America
| | - Dina Moustafa
- Emory University School of Medicine, Children’s Healthcare of Atlanta, Inc., Department of Pediatrics, and Center for Cystic Fibrosis and Airway Diseases Research, Atlanta, GA, United States of America
| | - Chari D. Smith
- Princeton University, Department of Molecular Biology, Princeton, NJ, United States of America
| | - Joanna B. Goldberg
- Emory University School of Medicine, Children’s Healthcare of Atlanta, Inc., Department of Pediatrics, and Center for Cystic Fibrosis and Airway Diseases Research, Atlanta, GA, United States of America
| | - Bonnie L. Bassler
- Princeton University, Department of Molecular Biology, Princeton, NJ, United States of America
- Howard Hughes Medical Institute, Chevy Chase, MD, United States of America
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19
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Inhibition of Pseudomonas aeruginosa by Peptide-Conjugated Phosphorodiamidate Morpholino Oligomers. Antimicrob Agents Chemother 2017; 61:AAC.01938-16. [PMID: 28137807 DOI: 10.1128/aac.01938-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/09/2017] [Indexed: 01/01/2023] Open
Abstract
Pseudomonas aeruginosa is a highly virulent, multidrug-resistant pathogen that causes significant morbidity and mortality in hospitalized patients and is particularly devastating in patients with cystic fibrosis. Increasing antibiotic resistance coupled with decreasing numbers of antibiotics in the developmental pipeline demands novel antibacterial approaches. Here, we tested peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs), which inhibit translation of complementary mRNA from specific, essential genes in P. aeruginosa PPMOs targeted to acpP, lpxC, and rpsJ, inhibited P. aeruginosa growth in many clinical strains and activity of PPMOs could be enhanced 2- to 8-fold by the addition of polymyxin B nonapeptide at subinhibitory concentrations. The PPMO targeting acpP was also effective at preventing P. aeruginosa PAO1 biofilm formation and at reducing existing biofilms. Importantly, treatment with various combinations of a PPMO and a traditional antibiotic demonstrated synergistic growth inhibition, the most effective of which was the PPMO targeting rpsJ with tobramycin. Furthermore, treatment of P. aeruginosa PA103-infected mice with PPMOs targeting acpP, lpxC, or rpsJ significantly reduced the bacterial burden in the lungs at 24 h by almost 3 logs. Altogether, this study demonstrates that PPMOs targeting the essential genes acpP, lpxC, or rpsJ in P. aeruginosa are highly effective at inhibiting growth in vitro and in vivo These data suggest that PPMOs alone or in combination with antibiotics represent a novel approach to addressing the problems associated with rapidly increasing antibiotic resistance in P. aeruginosa.
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20
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Bearss JJ, Hunter M, Dankmeyer JL, Fritts KA, Klimko CP, Weaver CH, Shoe JL, Quirk AV, Toothman RG, Webster WM, Fetterer DP, Bozue JA, Worsham PL, Welkos SL, Amemiya K, Cote CK. Characterization of pathogenesis of and immune response to Burkholderia pseudomallei K96243 using both inhalational and intraperitoneal infection models in BALB/c and C57BL/6 mice. PLoS One 2017; 12:e0172627. [PMID: 28235018 PMCID: PMC5325312 DOI: 10.1371/journal.pone.0172627] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 02/07/2017] [Indexed: 01/02/2023] Open
Abstract
Burkholderia pseudomallei, the etiologic agent of melioidosis, is a Gram negative bacterium designated as a Tier 1 threat. This bacterium is known to be endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. Inhalational melioidosis has been associated with monsoonal rains in endemic areas and is also a significant concern in the biodefense community. There are currently no effective vaccines for B. pseudomallei and antibiotic treatment can be hampered by non-specific symptomology and also the high rate of naturally occurring antibiotic resistant strains. Well-characterized animal models will be essential when selecting novel medical countermeasures for evaluation prior to human clinical trials. Here, we further characterize differences between the responses of BALB/c and C57BL/6 mice when challenged with low doses of a low-passage and well-defined stock of B. pseudomallei K96243 via either intraperitoneal or aerosol routes of exposure. Before challenge, mice were implanted with a transponder to collect body temperature readings, and daily body weights were also recorded. Mice were euthanized on select days for pathological analyses and determination of the bacterial burden in selected tissues (blood, lungs, liver, and spleen). Additionally, spleen homogenate and sera samples were analyzed to better characterize the host immune response after infection with aerosolized bacteria. These clinical, pathological, and immunological data highlighted and confirmed important similarities and differences between these murine models and exposure routes.
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Affiliation(s)
- Jeremy J. Bearss
- Pathology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD, United States of America
| | - Melissa Hunter
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Jennifer L. Dankmeyer
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Kristen A. Fritts
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Christopher P. Klimko
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Chris H. Weaver
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Jennifer L. Shoe
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Avery V. Quirk
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Ronald G. Toothman
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Wendy M. Webster
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - David P. Fetterer
- BioStatisitics Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Joel A. Bozue
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Patricia L. Worsham
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Susan L. Welkos
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Kei Amemiya
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
| | - Christopher K. Cote
- Bacteriology Division, USAMRIID, Fort Detrick, Frederick, MD, United States of America
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21
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Okerblom JJ, Schwarz F, Olson J, Fletes W, Ali SR, Martin PT, Glass CK, Nizet V, Varki A. Loss of CMAH during Human Evolution Primed the Monocyte-Macrophage Lineage toward a More Inflammatory and Phagocytic State. THE JOURNAL OF IMMUNOLOGY 2017; 198:2366-2373. [PMID: 28148732 DOI: 10.4049/jimmunol.1601471] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/04/2017] [Indexed: 12/21/2022]
Abstract
Humans and chimpanzees are more sensitive to endotoxin than are mice or monkeys, but any underlying differences in inflammatory physiology have not been fully described or understood. We studied innate immune responses in Cmah-/- mice, emulating human loss of the gene encoding production of Neu5Gc, a major cell surface sialic acid. CMP-N-acetylneuraminic acid hydroxylase (CMAH) loss occurred ∼2-3 million years ago, after the common ancestor of humans and chimpanzees, perhaps contributing to speciation of the genus HomoCmah-/- mice manifested a decreased survival in endotoxemia following bacterial LPS injection. Macrophages from Cmah-/- mice secreted more inflammatory cytokines with LPS stimulation and showed more phagocytic activity. Macrophages and whole blood from Cmah-/- mice also killed bacteria more effectively. Metabolic reintroduction of Neu5Gc into Cmah-/- macrophages suppressed these differences. Cmah-/- mice also showed enhanced bacterial clearance during sublethal lung infection. Although monocytes and monocyte-derived macrophages from humans and chimpanzees exhibited marginal differences in LPS responses, human monocyte-derived macrophages killed Escherichia coli and ingested E. coli BioParticles better. Metabolic reintroduction of Neu5Gc into human macrophages suppressed these differences. Although multiple mechanisms are likely involved, one cause is altered expression of C/EBPβ, a transcription factor affecting macrophage function. Loss of Neu5Gc in Homo likely had complex effects on immunity, providing greater capabilities to clear sublethal bacterial challenges, possibly at the cost of endotoxic shock risk. This trade-off may have provided a selective advantage when Homo transitioned to butchery using stone tools. The findings may also explain why the Cmah-/- state alters severity in mouse models of human disease.
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Affiliation(s)
- Jonathan J Okerblom
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Flavio Schwarz
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Josh Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - William Fletes
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Initiative for Maximizing Student Development Program, University of California, San Diego, La Jolla, CA 92093
| | - Syed Raza Ali
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Paul T Martin
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 42305.,Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, OH 43210; and.,Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205
| | - Christopher K Glass
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Victor Nizet
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093.,Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Ajit Varki
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093; .,Department of Medicine, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
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22
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Collective Resistance in Microbial Communities by Intracellular Antibiotic Deactivation. PLoS Biol 2016; 14:e2000631. [PMID: 28027306 PMCID: PMC5189934 DOI: 10.1371/journal.pbio.2000631] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/23/2016] [Indexed: 11/29/2022] Open
Abstract
The structure and composition of bacterial communities can compromise antibiotic efficacy. For example, the secretion of β-lactamase by individual bacteria provides passive resistance for all residents within a polymicrobial environment. Here, we uncover that collective resistance can also develop via intracellular antibiotic deactivation. Real-time luminescence measurements and single-cell analysis demonstrate that the opportunistic human pathogen Streptococcus pneumoniae grows in medium supplemented with chloramphenicol (Cm) when resistant bacteria expressing Cm acetyltransferase (CAT) are present. We show that CAT processes Cm intracellularly but not extracellularly. In a mouse pneumonia model, more susceptible pneumococci survive Cm treatment when coinfected with a CAT-expressing strain. Mathematical modeling predicts that stable coexistence is only possible when antibiotic resistance comes at a fitness cost. Strikingly, CAT-expressing pneumococci in mouse lungs were outcompeted by susceptible cells even during Cm treatment. Our results highlight the importance of the microbial context during infectious disease as a potential complicating factor to antibiotic therapy. Antibiotic-resistant bacterial infections are on the rise and pose a serious threat to society. The influence of genetic resistance mechanisms on antibiotic therapy is well described. However, other factors, such as epigenetic resistance or the impact of the environment on antibiotic therapy, are less well understood. Here, we describe and characterize a mechanism of noninherited antibiotic resistance that enables the survival and outgrowth of genetically susceptible bacteria during antibiotic therapy. We show that bacteria expressing the resistance factor chloramphenicol (Cm) acetyltransferase (CAT) can potently deactivate Cm in their immediate environment. The reduced Cm concentration then allows for the outgrowth of genetically susceptible bacteria in the same environment. Mathematical modeling demonstrates the presence of a parameter space in which stable coexistence between Cm-susceptible and -resistant bacteria is possible during antibiotic therapy, which we validated using single-cell analyses. Strikingly, mixed culture experiments in which mice were infected with both Cm-susceptible and -resistant pneumococci revealed that Cm-sensitive “freeloader” bacteria even outcompeted resistant bacteria during antibiotic therapy. Together, we show that the microbial context during infection is a potential complicating factor to antibiotic treatment outcomes.
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23
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Madenspacher JH, Fessler MB. A Non-invasive and Technically Non-intensive Method for Induction and Phenotyping of Experimental Bacterial Pneumonia in Mice. J Vis Exp 2016. [PMID: 27768086 DOI: 10.3791/54508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Although community-acquired pneumonia remains a major public health problem, murine models of bacterial pneumonia have recently facilitated significant preclinical advances in our understanding of the underlying cellular and molecular pathogenesis. In vivo mouse models capture the integrated physiology and resilience of the host defense response in a manner not revealed by alternative, simplified ex vivo approaches. Several methods have been described in the literature for intrapulmonary inoculation of bacteria in mice, including aerosolization, intranasal delivery, peroral endotracheal cannulation under 'blind' and visualized conditions, and transcutaneous endotracheal cannulation. All methods have relative merits and limitations. Herein, we describe in detail a non-invasive, technically non-intensive, inexpensive, and rapid method for intratracheal delivery of bacteria that involves aspiration (i.e., inhalation) by the mouse of an infectious inoculum pipetted into the oropharynx while under general anesthesia. This method can be used for pulmonary delivery of a wide variety of non-caustic biological and chemical agents, and is relatively easy to learn, even for laboratories with minimal prior experience with pulmonary procedures. In addition to describing the aspiration pneumonia method, we also provide step-by-step procedures for assaying the subsequent in vivo pulmonary innate immune response of the mouse, in particular, methods for quantifying bacterial clearance and the cellular immune response of the infected airway. This integrated and simple approach to pneumonia assessment allows for rapid and robust evaluation of the effect of genetic and environmental manipulations upon pulmonary innate immunity.
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Affiliation(s)
- Jennifer H Madenspacher
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health
| | - Michael B Fessler
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health;
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24
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Gutierrez MG, Yoder-Himes DR, Warawa JM. Comprehensive identification of virulence factors required for respiratory melioidosis using Tn-seq mutagenesis. Front Cell Infect Microbiol 2015; 5:78. [PMID: 26583079 PMCID: PMC4631991 DOI: 10.3389/fcimb.2015.00078] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/21/2015] [Indexed: 12/23/2022] Open
Abstract
Respiratory melioidosis is a disease presentation of the biodefense pathogen, Burkholderia pseudomallei, which is frequently associated with a lethal septicemic spread of the bacteria. We have recently developed an improved respiratory melioidosis model to study the pathogenesis of Burkholderia pseudomallei in the lung (intubation-mediated intratracheal [IMIT] inoculation), which more closely models descriptions of human melioidosis, including prominent septicemic spread from the lung and reduced involvement of the upper respiratory tract. We previously demonstrated that the Type 3 Secretion System cluster 3 (T3SS3) is a critical virulence determinant for B. pseudomallei when delivered directly into the lung. We decided to comprehensively identify all virulence determinants required for respiratory melioidosis using the Tn-seq phenotypic screen, as well as to investigate which virulence determinants are required for dissemination to the liver and spleen. While previous studies have used Tn-seq to identify essential genes for in vitro cultured B. pseudomallei, this represents the first study to use Tn-seq to identify genes required for in vivo fitness. Consistent with our previous findings, we identified T3SS3 as the largest genetic cluster required for fitness in the lung. Furthermore, we identified capsular polysaccharide and Type 6 Secretion System cluster 5 (T6SS5) as the two additional major genetic clusters facilitating respiratory melioidosis. Importantly, Tn-seq did not identify additional, novel large genetic systems supporting respiratory melioidosis, although these studies identified additional small gene clusters that may also play crucial roles in lung fitness. Interestingly, other previously identified virulence determinants do not appear to be required for lung fitness, such as lipopolysaccharide. The role of T3SS3, capsule, and T6SS5 in lung fitness was validated by competition studies, but only T3SS3 was found to be important for respiratory melioidosis when delivered as a single strain challenge, suggesting that competition studies may provide a higher resolution analysis of fitness factors in the lung. The use of Tn-seq phenotypic screening also provided key insights into the selective pressure encountered in the liver.
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Affiliation(s)
- Maria G Gutierrez
- Department of Microbiology and Immunology, University of Louisville Louisville, KY, USA
| | | | - Jonathan M Warawa
- Department of Microbiology and Immunology, University of Louisville Louisville, KY, USA ; Center for Predictive Medicine, University of Louisville Louisville, KY, USA
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25
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Lin L, Nonejuie P, Munguia J, Hollands A, Olson J, Dam Q, Kumaraswamy M, Rivera H, Corriden R, Rohde M, Hensler ME, Burkart MD, Pogliano J, Sakoulas G, Nizet V. Azithromycin Synergizes with Cationic Antimicrobial Peptides to Exert Bactericidal and Therapeutic Activity Against Highly Multidrug-Resistant Gram-Negative Bacterial Pathogens. EBioMedicine 2015; 2:690-8. [PMID: 26288841 PMCID: PMC4534682 DOI: 10.1016/j.ebiom.2015.05.021] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 05/21/2015] [Accepted: 05/21/2015] [Indexed: 12/22/2022] Open
Abstract
Antibiotic resistance poses an increasingly grave threat to the public health. Of pressing concern, rapid spread of carbapenem-resistance among multidrug-resistant (MDR) Gram-negative rods (GNR) is associated with few treatment options and high mortality rates. Current antibiotic susceptibility testing guiding patient management is performed in a standardized manner, identifying minimum inhibitory concentrations (MIC) in bacteriologic media, but ignoring host immune factors. Lacking activity in standard MIC testing, azithromycin (AZM), the most commonly prescribed antibiotic in the U.S., is never recommended for MDR GNR infection. Here we report a potent bactericidal action of AZM against MDR carbapenem-resistant isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. This pharmaceutical activity is associated with enhanced AZM cell penetration in eukaryotic tissue culture media and striking multi-log-fold synergies with host cathelicidin antimicrobial peptide LL-37 or the last line antibiotic colistin. Finally, AZM monotherapy exerts clear therapeutic effects in murine models of MDR GNR infection. Our results suggest that AZM, currently ignored as a treatment option, could benefit patients with MDR GNR infections, especially in combination with colistin. Standard MIC testing conditions overlook a potent activity of azithromycin vs. multidrug-resistant Gram-negative bacteria. Colistin and endogenous host defense peptide LL-37 markedly potentiate azithromycin penetration into bacterial cells. Azithromycin reduced bacterial load and mortality in mouse models of multidrug-resistant Gram-negative infection.
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Affiliation(s)
- Leo Lin
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Poochit Nonejuie
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason Munguia
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew Hollands
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joshua Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Quang Dam
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Monika Kumaraswamy
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heriberto Rivera
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Ross Corriden
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Mary E Hensler
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Joe Pogliano
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - George Sakoulas
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA ; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA ; Rady Children's Hospital, San Diego, CA 92123, USA
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26
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Gutierrez MG, Pfeffer TL, Warawa JM. Type 3 secretion system cluster 3 is a critical virulence determinant for lung-specific melioidosis. PLoS Negl Trop Dis 2015; 9:e3441. [PMID: 25569630 PMCID: PMC4287560 DOI: 10.1371/journal.pntd.0003441] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/24/2014] [Indexed: 01/20/2023] Open
Abstract
Burkholderia pseudomallei, the bacterial agent of melioidosis, causes disease through inhalation of infectious particles, and is classified as a Tier 1 Select Agent. Optical diagnostic imaging has demonstrated that murine respiratory disease models are subject to significant upper respiratory tract (URT) colonization. Because human melioidosis is not associated with URT colonization as a prominent presentation, we hypothesized that lung-specific delivery of B. pseudomallei may enhance our ability to study respiratory melioidosis in mice. We compared intranasal and intubation-mediated intratracheal (IMIT) instillation of bacteria and found that the absence of URT colonization correlates with an increased bacterial pneumonia and systemic disease progression. Comparison of the LD50 of luminescent B. pseudomallei strain, JW280, in intranasal and IMIT challenges of albino C57BL/6J mice identified a significant decrease in the LD50 using IMIT. We subsequently examined the LD50 of both capsular polysaccharide and Type 3 Secretion System cluster 3 (T3SS3) mutants by IMIT challenge of mice and found that the capsule mutant was attenuated 6.8 fold, while the T3SS3 mutant was attenuated 290 fold, demonstrating that T3SS3 is critical to respiratory melioidosis. Our previously reported intranasal challenge studies, which involve significant URT colonization, did not identify a dissemination defect for capsule mutants; however, we now report that capsule mutants exhibit significantly reduced dissemination from the lung following lung-specific instillation, suggesting that capsule mutants are competent to spread from the URT, but not the lung. We also report that a T3SS3 mutant is defective for dissemination following lung-specific delivery, and also exhibits in vivo growth defects in the lung. These findings highlight the T3SS3 as a critical virulence system for respiratory melioidosis, not only in the lung, but also for subsequent spread beyond the lung using a model system uniquely capable to characterize the fate of lung-delivered pathogen. Respiratory melioidosis is a lethal disease presentation of the bacterium Burkholderia pseudomallei, which is found in tropical regions worldwide. Respiratory melioidosis has also been highlighted as a concern in the biodefense community given the potential for weaponization of B. pseudomallei. This study demonstrates that respiratory melioidosis models can significantly vary in their disease presentations in mice, depending on whether the upper respiratory tract represents an initial site of infection. We have demonstrated that lung-specific infections of mice, which avoid nasal cavity colonization, result in a course of disease with greater maturation of pneumonia and systemic spread, and we propose that this represents a critical advance in the field of studying respiratory melioidosis. We further characterize that the capsule virulence determinant, previously considered important for respiratory melioidosis, has reduced significance when characterized in the context of lung-specific disease, while the Type 3 Secretion System cluster 3 is a critical virulence determinant for B. pseudomallei required for efficient colonization of the lung as well as spread to other tissues.
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Affiliation(s)
- Maria G. Gutierrez
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America
| | - Tia L. Pfeffer
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America
| | - Jonathan M. Warawa
- Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America
- Center for Predictive Medicine, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
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Schully KL, Bell MG, Ward JM, Keane-Myers AM. Oropharyngeal aspiration of Burkholderia mallei and Burkholderia pseudomallei in BALB/c mice. PLoS One 2014; 9:e115066. [PMID: 25503969 PMCID: PMC4263729 DOI: 10.1371/journal.pone.0115066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 11/18/2014] [Indexed: 01/22/2023] Open
Abstract
Burkholderia mallei and Burkholderia pseudomallei are potentially lethal pathogens categorized as biothreat agents due, in part, to their ability to be disseminated via aerosol. There are no protective vaccines against these pathogens and treatment options are limited and cumbersome. Since disease severity is greatest when these agents are inhaled, efforts to develop pre- or post-exposure prophylaxis focus largely on inhalation models of infection. Here, we demonstrate a non-invasive and technically simple method for affecting the inhalational challenge of BALB/c mice with B. pseudomallei and B. mallei. In this model, two investigators utilized common laboratory tools such as forceps and a micropipette to conduct and characterize an effective and reproducible inhalational challenge of BALB/c mice with B. mallei and B. pseudomallei. Challenge by oropharyngeal aspiration resulted in acute disease. Additionally, 50% endpoints for B. pseudomallei K96243 and B. mallei ATCC 23344 were nearly identical to published aerosol challenge methods. Furthermore, the pathogens disseminated to all major organs typically targeted by these agents where they proliferated. The pro-inflammatory cytokine production in the proximal and peripheral fluids demonstrated a rapid and robust immune response comparable to previously described murine and human studies. These observations demonstrate that OA is a viable alternative to aerosol exposure.
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Affiliation(s)
- Kevin L. Schully
- Naval Medical Research Center-Frederick, Frederick, Maryland, United States of America
| | - Matthew G. Bell
- Naval Medical Research Center-Frederick, Frederick, Maryland, United States of America
| | - Jerrold M. Ward
- Global Vet Pathology, Montgomery Village, Maryland, United States of America
| | - Andrea M. Keane-Myers
- Naval Medical Research Center-Frederick, Frederick, Maryland, United States of America
- * E-mail:
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Administration of antenatal glucocorticoids and postnatal surfactant ameliorates respiratory distress syndrome-associated neonatal lethality in Erk3(-/-) mouse pups. Pediatr Res 2014; 76:24-32. [PMID: 24732107 PMCID: PMC4062596 DOI: 10.1038/pr.2014.54] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 01/03/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Respiratory distress syndrome (RDS) persists as a prevalent cause of infant morbidity and mortality. We have previously demonstrated that deletion of Erk3 results in pulmonary immaturity and neonatal lethality. Using RNA sequencing, we identified corticotrophin releasing hormone (CRH) and surfactant protein B (SFTPB) as potential molecular mediators of Erk3-dependent lung maturation. In this study, we characterized the impact of antenatal glucocorticoids and postnatal surfactant on neonatal survival of Erk3 null mice. METHODS In a double crossover design, we administered dexamethasone (dex) or saline to pregnant dams during the saccular stage of lung development, followed by postnatal surfactant or saline via inhalation intubation. Survival was recorded, and detailed lung histological analysis and staining for CRH and SFTPB protein expression were performed. RESULTS Without treatment, Erk3 null pups die within 6 h of birth with reduced aerated space, impaired thinning of the alveolar septa, and abundant glycogen stores, as described in human RDS. The administration of dex and surfactant improved RDS-associated lethality of Erk3(-/-) pups and partially restored functional fetal lung maturation by accelerating the downregulation of pulmonary CRH and partially rescuing the production of SFTPB. CONCLUSION These findings emphasize that Erk3 is integral to terminal differentiation of type II cells, SFTPB production, and fetal pulmonary maturity.
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Lafontaine ER, Balder R, Michel F, Hogan RJ. Characterization of an autotransporter adhesin protein shared by Burkholderia mallei and Burkholderia pseudomallei. BMC Microbiol 2014; 14:92. [PMID: 24731253 PMCID: PMC4021183 DOI: 10.1186/1471-2180-14-92] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 04/08/2014] [Indexed: 12/21/2022] Open
Abstract
Background Autotransporters form a large family of outer membrane proteins specifying diverse biological traits of Gram-negative bacteria. In this study, we report the identification and characterization of a novel autotransporter gene product of Burkholderia mallei (locus tag BMA1027 in strain ATCC 23344). Results Database searches identified the gene in at least seven B. mallei isolates and the encoded proteins were found to be 84% identical. Inactivation of the gene encoding the autotransporter in the genome of strain ATCC 23344 substantially reduces adherence to monolayers of HEp-2 laryngeal cells and A549 type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, expression of the autotransporter on the surface of recombinant E. coli bacteria increases adherence to these cell types by 5–7 fold. The gene specifying the autotransporter was identified in the genome of 29 B. pseudomallei isolates and disruption of the gene in strain DD503 reduced adherence to NHBE cultures by 61%. Unlike B. mallei, the mutation did not impair binding of B. pseudomallei to A549 or HEp-2 cells. Analysis of sera from mice infected via the aerosol route with B. mallei and B. pseudomallei revealed that animals inoculated with as few as 10 organisms produce antibodies against the autotransporter, therefore indicating expression in vivo. Conclusions Our data demonstrate that we have identified an autotransporter protein common to the pathogenic species B. mallei and B. pseudomallei which mediates adherence to respiratory epithelial cells and is expressed in vivo during the course of aerosol infection.
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Affiliation(s)
- Eric R Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, 30602 Athens, GA, USA.
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Allen IC. The utilization of oropharyngeal intratracheal PAMP administration and bronchoalveolar lavage to evaluate the host immune response in mice. J Vis Exp 2014. [PMID: 24747836 DOI: 10.3791/51391] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The host immune response to pathogens is a complex biological process. The majority of in vivo studies classically employed to characterize host-pathogen interactions take advantage of intraperitoneal injections of select bacteria or pathogen associated molecular patterns (PAMPs) in mice. While these techniques have yielded tremendous data associated with infectious disease pathobiology, intraperitoneal injection models are not always appropriate for host-pathogen interaction studies in the lung. Utilizing an acute lung inflammation model in mice, it is possible to conduct a high resolution analysis of the host innate immune response utilizing lipopolysaccharide (LPS). Here, we describe the methods to administer LPS using nonsurgical oropharyngeal intratracheal administration, monitor clinical parameters associated with disease pathogenesis, and utilize bronchoalveolar lavage fluid to evaluate the host immune response. The techniques that are described are widely applicable for studying the host innate immune response to a diverse range of PAMPs and pathogens. Likewise, with minor modifications, these techniques can also be applied in studies evaluating allergic airway inflammation and in pharmacological applications.
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Affiliation(s)
- Irving C Allen
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University;
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Key role of Toll-like receptor 2 in the inflammatory response and major histocompatibility complex class ii downregulation in Brucella abortus-infected alveolar macrophages. Infect Immun 2013; 82:626-39. [PMID: 24478078 DOI: 10.1128/iai.01237-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Alveolar macrophages (AM) seem to constitute the main cellular target of inhaled brucellae. Here, we show that Brucella abortus invades and replicates in murine AM without inducing cytotoxicity. B. abortus infection induced a statistically significant increase of tumor necrosis factor alpha (TNF-α), CXCL1 or keratinocyte chemoattractant (KC), interleukin-1β (IL-1β), IL-6, and IL-12 in AM from C57BL/6 mice and BALB/c mice, but these responses were generally weaker and/or delayed compared to those elicited in peritoneal macrophages. Studies using knockout mice for TLR2, TLR4, and TLR9 revealed that TNF-α and KC responses were mediated by TLR2 recognition. Brucella infection reduced in a multiplicity of infection-dependent manner the expression of major histocompatibility complex class II (MHC-II) molecules induced by gamma interferon (IFN-γ) in AM. The same phenomenon was induced by incubation with heat-killed B. abortus (HKBA) or the lipidated form of the 19-kDa outer membrane protein of Brucella (L-Omp19), and it was shown to be mediated by TLR2 recognition. In contrast, no significant downregulation of MHC-II was induced by either unlipidated Omp19 or Brucella LPS. In a functional assay, treatment of AM with either L-Omp19 or HKBA reduced the MHC-II-restricted presentation of OVA peptides to specific T cells. One week after intratracheal infection, viable B. abortus was detected in AM from both wild-type and TLR2 KO mice, but CFU counts were higher in the latter. These results suggest that B. abortus survives in AM after inhalatory infection in spite of a certain degree of immune control exerted by the TLR2-mediated inflammatory response. Both the modest nature of the latter and the modulation of MHC-II expression by the bacterium may contribute to such survival.
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Lafontaine ER, Zimmerman SM, Shaffer TL, Michel F, Gao X, Hogan RJ. Use of a safe, reproducible, and rapid aerosol delivery method to study infection by Burkholderia pseudomallei and Burkholderia mallei in mice. PLoS One 2013; 8:e76804. [PMID: 24098563 PMCID: PMC3788738 DOI: 10.1371/journal.pone.0076804] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/26/2013] [Indexed: 11/24/2022] Open
Abstract
Burkholderia pseudomallei, the etiologic agent of melioidosis, is a saprophytic bacterium readily isolated from wet soils of countries bordering the equator. Burkholderia mallei is a host-adapted clone of B. pseudomallei that does not persist outside of its equine reservoir and causes the zoonosis glanders, which is endemic in Asia, Africa, the Middle East and South America. Infection by these organisms typically occurs via percutaneous inoculation or inhalation of aerosols, and the most common manifestation is severe pneumonia leading to fatal bacteremia. Glanders and melioidosis are difficult to diagnose and require prolonged antibiotic therapy with low success rates. There are no vaccines available to protect against either Burkholderia species, and there is concern regarding their use as biological warfare agents given that B. mallei has previously been utilized in this manner. Hence, experiments were performed to establish a mouse model of aerosol infection to study the organisms and develop countermeasures. Using a hand-held aerosolizer, BALB/c mice were inoculated intratracheally with strains B. pseudomallei 1026b and B. mallei ATCC23344 and growth of the agents in the lungs, as well as dissemination to the spleen, were examined. Mice infected with 102, 103 and 104 organisms were unable to control growth of B. mallei in the lungs and bacteria rapidly disseminated to the spleen. Though similar results were observed in mice inoculated with 103 and 104B. pseudomallei cells, animals infected with 102 organisms controlled bacterial replication in the lungs, dissemination to the spleen, and the extent of bacteremia. Analysis of sera from mice surviving acute infection revealed that animals produced antibodies against antigens known to be targets of the immune response in humans. Taken together, these data show that small volume aerosol inoculation of mice results in acute disease, dose-dependent chronic infection, and immune responses that correlate with those seen in human infections.
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Affiliation(s)
- Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Shawn M. Zimmerman
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Teresa L. Shaffer
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
| | - Xiudan Gao
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
| | - Robert J. Hogan
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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