1
|
Leroy AG, Caillon J, Broquet A, Lemabecque V, Delanou S, Caroff N, Asehnoune K, Roquilly A, Crémet L. Azithromycin regulates bacterial virulence and immune response in a murine model of ceftazidime-treated Pseudomonas aeruginosa acute pneumonia. Microbiol Immunol 2024; 68:27-35. [PMID: 38073281 DOI: 10.1111/1348-0421.13106] [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: 08/02/2023] [Revised: 11/06/2023] [Accepted: 11/16/2023] [Indexed: 02/07/2024]
Abstract
Pseudomonas aeruginosa (PA) remains one of the leading causes of nosocomial acute pneumonia. The array of virulence factors expressed by PA and the intense immune response associated with PA pneumonia play a major role in the severity of these infections. New therapeutic approaches are needed to overcome the high resistance of PA to antibiotics and to reduce the direct damage to host tissues. Through its immunomodulatory and anti-virulence effects, azithromycin (AZM) has demonstrated clinical benefits in patients with chronic PA respiratory infections. However, there is relatively little evidence in PA acute pneumonia. We investigated the effects of AZM, as an adjunctive therapy combined with ceftazidime (CAZ), in a murine model of PA acute pneumonia. We observed that the combined therapy (i) reduces the weight loss of mice 24 h post-infection (hpi), (ii) decreases neutrophil influx into the lungs at 6 and 24 hpi, while this effect is absent in a LPS-induced pneumonia or when PA is pretreated with antibiotics and mice do not receive any antibiotics, and that (iii) AZM, alone or with CAZ, modulates the expression of PA quorum sensing regulators and virulence factors (LasI, LasA, PqsE, PhzM, ExoS). Our findings support beneficial effects of AZM with CAZ on PA acute pneumonia by both bacterial virulence and immune response modulations. Further investigations are needed to clarify the exact underlying mechanisms responsible for the reduction of the neutrophils influx and to better discriminate between direct immunomodulatory properties of AZM, and indirect effects on neutrophilia resulting from bacterial virulence modulation.
Collapse
Affiliation(s)
- A-G Leroy
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
- CHU de Nantes, Service de Bactériologie-Hygiène Hospitalière, Nantes Université, Nantes, France
| | - J Caillon
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
- CHU de Nantes, Service de Bactériologie-Hygiène Hospitalière, Nantes Université, Nantes, France
| | - A Broquet
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
| | - V Lemabecque
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
| | - S Delanou
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
| | - N Caroff
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
| | - K Asehnoune
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
- Service Anesthésie Réanimation Chirurgicale, CHU de Nantes, Nantes Université, Nantes, France
| | - A Roquilly
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
- Service Anesthésie Réanimation Chirurgicale, CHU de Nantes, Nantes Université, Nantes, France
| | - L Crémet
- Center for Research in Transplantation and Translational Immunology, Nantes Université, CHU Nantes, INSERM, Nantes, France
- CHU de Nantes, Service de Bactériologie-Hygiène Hospitalière, Nantes Université, Nantes, France
| |
Collapse
|
2
|
Petcharat K, Munkong N, Thongboontho R, Chartarrayawadee W, Thim-Uam A. Synergistic Effects of Azithromycin and STING Agonist Promote IFN-I Production by Enhancing the Activation of STING-TBK1 Signaling. J Exp Pharmacol 2023; 15:407-421. [PMID: 37933302 PMCID: PMC10625772 DOI: 10.2147/jep.s433181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/28/2023] [Indexed: 11/08/2023] Open
Abstract
Background Azithromycin (AZM) is a macrolide antibiotic that exhibits anti-inflammatory and anti-viral infection properties by enhancing type-I interferon (IFN-I) responses. The stimulator of interferon genes (STING) can directly induce IFN-I production. However, elevated IFN-I induces auto-immune phenotypes such as systemic lupus erythematosus (SLE). The effects of AZM and STING on the production of IFN-I are unclear. Objective Therefore, this study aims to evaluate the role of AZM and STING on IFN-I responses in macrophages. Methods RAW 264.7 macrophages were treated with AZM with and without a STING-agonist (DMXAA), and the maturation of macrophages was determined using flow cytometry. Gene expression and pro-inflammatory cytokines were analyzed using qPCR and ELISA, respectively. Moreover, protein expression was investigated using Western blot assays and immunofluorescence. Results Our results show that AZM significantly induced M1 phenotypes, promoting surface molecule expansion of CD80 and MHC-II and production of IL-6 and TNF-α cytokines on DMXAA-stimulated macrophages. Furthermore, we found that AZM-increased mRNA levels of interferon-stimulated genes (ISGs) could be due to the high expression of STNG-TBK1 signaling in the presence of DMXAA. Conclusion Our data suggest that AZM enhancement of IFN-I responses was STING dependent in DMXAA-stimulated macrophages. These data underline a novel approach to AZM action-mediated STING-TBK1 signaling for regulating IFN-I responses and may further augment the scientific basis and potential use of AZM in clinical applications.
Collapse
Affiliation(s)
- Kanoktip Petcharat
- Division of Biochemistry, School of Medical Sciences, University of Phayao, Phayao, 56000, Thailand
| | - Narongsuk Munkong
- Department of Pathology, School of Medicine, University of Phayao, Phayao, 56000, Thailand
| | - Rungthip Thongboontho
- Division of Biochemistry, School of Medical Sciences, University of Phayao, Phayao, 56000, Thailand
| | | | - Arthid Thim-Uam
- Division of Biochemistry, School of Medical Sciences, University of Phayao, Phayao, 56000, Thailand
| |
Collapse
|
3
|
Sandri A, Saitta GM, Veschetti L, Boschi F, Passarelli Mantovani R, Carelli M, Melotti P, Signoretto C, Boaretti M, Malerba G, Lleò MM. In Vivo Inflammation Caused by Achromobacter spp. Cystic Fibrosis Clinical Isolates Exhibiting Different Pathogenic Characteristics. Int J Mol Sci 2023; 24:ijms24087432. [PMID: 37108596 PMCID: PMC10139000 DOI: 10.3390/ijms24087432] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Achromobacter spp. lung infection in cystic fibrosis has been associated with inflammation, increased frequency of exacerbations, and decline of respiratory function. We aimed to evaluate in vivo the inflammatory effects of clinical isolates exhibiting different pathogenic characteristics. Eight clinical isolates were selected based on different pathogenic characteristics previously assessed: virulence in Galleria mellonella larvae, cytotoxicity in human bronchial epithelial cells, and biofilm formation. Acute lung infection was established by intratracheal instillation with 10.5 × 108 bacterial cells in wild-type and CFTR-knockout (KO) mice expressing a luciferase gene under control of interleukin-8 promoter. Lung inflammation was monitored by in vivo bioluminescence imaging up to 48 h after infection, and mortality was recorded up to 96 h. Lung bacterial load was evaluated by CFU count. Virulent isolates caused higher lung inflammation and mice mortality, especially in KO animals. Isolates both virulent and cytotoxic showed higher persistence in mice lungs, while biofilm formation was not associated with lung inflammation, mice mortality, or bacterial persistence. A positive correlation between virulence and lung inflammation was observed. These results indicate that Achromobacter spp. pathogenic characteristics such as virulence and cytotoxicity may be associated with clinically relevant effects and highlight the importance of elucidating their mechanisms.
Collapse
Affiliation(s)
- Angela Sandri
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Giulia Maria Saitta
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Laura Veschetti
- GMLab, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Federico Boschi
- Department of Engineering for Innovation Medicine, University of Verona, 37134 Verona, Italy
| | - Rebeca Passarelli Mantovani
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Maria Carelli
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Paola Melotti
- Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata Verona, 37126 Verona, Italy
| | - Caterina Signoretto
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Marzia Boaretti
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| | - Giovanni Malerba
- GMLab, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
| | - Maria M Lleò
- Department of Diagnostics and Public Health, Microbiology Section, University of Verona, 37134 Verona, Italy
| |
Collapse
|
4
|
Dudala SS, Venkateswarulu TC, Kancharla SC, Kodali VP, Babu DJ. A review on importance of bioactive compounds of medicinal plants in treating idiopathic pulmonary fibrosis (special emphasis on isoquinoline alkaloids). FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2021. [DOI: 10.1186/s43094-021-00304-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abstract
Background
Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease of unknown cause which disrupts the normal lung architecture and functions by deregulating immune responses and ultimately leads to the death of the individual. A number of factors can lead to its development and currently there is no cure for this disease.
Main text
There are synthetic drugs available to relieve the symptoms and decelerate its development by targeting pathways involved in the development of IPF, but there had also been various side effects detected by their usage. It is known since decades that medicinal plants and their compounds have been used all over the world in natural medicines to cure various diseases. This review article is focused on the effects of various natural bioactive compounds of 26 plant extracts that show prophylactic and therapeutic properties against the disease and so can be used in treating IPF replacing synthetic drugs and reducing the side effects.
Short conclusion
This review includes different mechanisms that cause pulmonary fibrosis along with compounds that can induce fibrosis, drugs used for the treatment of pulmonary fibrosis, diagnosis, the biochemical tests used for the experimental study to determine the pathogenesis of disease with a special note on Isoquinoline alkaloids and their role in reducing various factors leading to IPF thus providing promising therapeutic approach.
Collapse
|
5
|
Nolan C, Behrends V. Sub-Inhibitory Antibiotic Exposure and Virulence in Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:antibiotics10111393. [PMID: 34827331 PMCID: PMC8615142 DOI: 10.3390/antibiotics10111393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is a prime opportunistic pathogen, one of the most important causes of hospital-acquired infections and the major cause of morbidity and mortality in cystic fibrosis lung infections. One reason for the bacterium's pathogenic success is the large array of virulence factors that it can employ. Another is its high degree of intrinsic and acquired resistance to antibiotics. In this review, we first summarise the current knowledge about the regulation of virulence factor expression and production. We then look at the impact of sub-MIC antibiotic exposure and find that the virulence-antibiotic interaction for P. aeruginosa is antibiotic-specific, multifaceted, and complex. Most studies undertaken to date have been in vitro assays in batch culture systems, involving short-term (<24 h) antibiotic exposure. Therefore, we discuss the importance of long-term, in vivo-mimicking models for future work, particularly highlighting the need to account for bacterial physiology, which by extension governs both virulence factor expression and antibiotic tolerance/resistance.
Collapse
|
6
|
Leroy AG, Caillon J, Caroff N, Broquet A, Corvec S, Asehnoune K, Roquilly A, Crémet L. Could Azithromycin Be Part of Pseudomonas aeruginosa Acute Pneumonia Treatment? Front Microbiol 2021; 12:642541. [PMID: 33796090 PMCID: PMC8008145 DOI: 10.3389/fmicb.2021.642541] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/26/2021] [Indexed: 12/29/2022] Open
Abstract
Azithromycin (AZM) is a 15-membered-ring macrolide that presents a broad-spectrum antimicrobial activity against Gram-positive bacteria and atypical microorganisms but suffers from a poor diffusion across the outer-membrane of Gram-negative bacilli, including Pseudomonas aeruginosa (PA). However, AZM has demonstrated clinical benefits in patients suffering from chronic PA respiratory infections, especially cystic fibrosis patients. Since the rise of multidrug-resistant PA has led to a growing need for new therapeutic options, this macrolide has been proposed as an adjunctive therapy. Clinical trials assessing AZM in PA acute pneumonia are scarce. However, a careful examination of the available literature provides good rationales for its use in that context. In fact, 14- and 15-membered-ring macrolides have demonstrated immunomodulatory and immunosuppressive effects that could be of major interest in the management of acute illness. Furthermore, growing evidence supports a downregulation of PA virulence dependent on direct interaction with the ribosomes, and based on the modulation of several key regulators from the Quorum Sensing network. First highlighted in vitro, these interesting properties of AZM have subsequently been confirmed in the animal models. In this review, we systematically analyzed the literature regarding AZM immunomodulatory and anti-PA effects. In vitro and in vivo studies, as well as clinical trials were reviewed, looking for rationales for AZM use in PA acute pneumonia.
Collapse
Affiliation(s)
- Anne-Gaëlle Leroy
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France.,CHU de Nantes, Service de Bactériologie-Hygiène hospitalière, Nantes Université, Nantes, France
| | - Jocelyne Caillon
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France.,CHU de Nantes, Service de Bactériologie-Hygiène hospitalière, Nantes Université, Nantes, France
| | - Nathalie Caroff
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France
| | - Alexis Broquet
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France
| | - Stéphane Corvec
- CHU de Nantes, Service de Bactériologie-Hygiène hospitalière, Nantes Université, Nantes, France.,CRCINA, U1232, CHU Nantes, Nantes, France
| | - Karim Asehnoune
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France.,CHU de Nantes, Service Anesthésie Réanimation Chirurgicale, Nantes Université, Nantes, France
| | - Antoine Roquilly
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France.,CHU de Nantes, Service Anesthésie Réanimation Chirurgicale, Nantes Université, Nantes, France
| | - Lise Crémet
- Laboratoire EA 3826 "Thérapeutiques cliniques et expérimentales des infections", IRS2-Nantes Biotech, Université de Nantes, Nantes, France.,CHU de Nantes, Service de Bactériologie-Hygiène hospitalière, Nantes Université, Nantes, France
| |
Collapse
|
7
|
Ozsvari B, Nuttall JR, Sotgia F, Lisanti MP. Azithromycin and Roxithromycin define a new family of "senolytic" drugs that target senescent human fibroblasts. Aging (Albany NY) 2018; 10:3294-3307. [PMID: 30428454 PMCID: PMC6286845 DOI: 10.18632/aging.101633] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/28/2018] [Indexed: 05/17/2023]
Abstract
Here, we employed a "senolytic" assay system as a screening tool, with the goal of identifying and repurposing FDA-approved antibiotics, for the targeting of the senescent cell population. Briefly, we used two established human fibroblast cell lines (MRC-5 and/or BJ) as model systems to induce senescence, via chronic treatment with a DNA-damaging agent, namely BrdU (at a concentration of 100 μM for 8 days). Cell viability was then monitored by using the SRB assay, to measure protein content. As a consequence of this streamlined screening strategy, we identified Azithromycin and Roxithromycin as two novel clinically-approved senolytic drugs. However, Erythromycin - the very closely-related parent compound - did not show any senolytic activity, highlighting the dramatic specificity of these interactions. Interestingly, we also show that Azithromycin treatment of human fibroblasts was indeed sufficient to strongly induce both aerobic glycolysis and autophagy. However, the effects of Azithromycin on mitochondrial oxygen consumption rates (OCR) were bi-phasic, showing inhibitory activity at 50 μM and stimulatory activity at 100 μM. These autophagic/metabolic changes induced by Azithromycin could mechanistically explain its senolytic activity. We also independently validated our findings using the xCELLigence real-time assay system, which measures electrical impedance. Using this approach, we see that Azithromycin preferentially targets senescent cells, removing approximately 97% of them with great efficiency. This represents a near 25-fold reduction in senescent cells. Finally, we also discuss our current results in the context of previous clinical findings that specifically document the anti-inflammatory activity of Azithromycin in patients with cystic fibrosis - a genetic lung disorder that results in protein mis-folding mutations that cause protein aggregation.
Collapse
Affiliation(s)
- Bela Ozsvari
- Translational Medicine, University of Salford, Greater Manchester, United Kingdom
- Equal contribution
| | - John R. Nuttall
- Translational Medicine, University of Salford, Greater Manchester, United Kingdom
- Equal contribution
| | - Federica Sotgia
- Translational Medicine, University of Salford, Greater Manchester, United Kingdom
| | - Michael P. Lisanti
- Translational Medicine, University of Salford, Greater Manchester, United Kingdom
| |
Collapse
|
8
|
Acquisition of resistance to carbapenem and macrolide-mediated quorum sensing inhibition by Pseudomonas aeruginosa via ICE Tn4371 6385. Commun Biol 2018; 1:57. [PMID: 30271939 PMCID: PMC6123621 DOI: 10.1038/s42003-018-0064-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 05/03/2018] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa can cause life-threatening infections in immunocompromised patients. The first-line agents to treat P. aeruginosa infections are carbapenems. However, the emergence of carbapenem-resistant P. aeruginosa strains greatly compromised the effectiveness of carbapenem treatment, which makes the surveillance on their spreading and transmission important. Here we characterized the full-length genomes of two carbapenem-resistant P. aeruginosa clinical isolates that are capable of producing New Delhi metallo-β-lactamase-1 (NDM-1). We show that blaNDM-1 is carried by a novel integrative and conjugative element (ICE) ICETn43716385, which also carries the macrolide resistance gene msr(E) and the florfenicol resistance gene floR. By exogenously expressing msr(E) in P. aeruginosa laboratory strains, we show that Msr(E) can abolish azithromycin-mediated quorum sensing inhibition in vitro and anti-Pseudomonas effect in vivo. We conclude that ICEs are important in transmitting carbapenem resistance, and that anti-virulence treatment of P. aeruginosa infections using sub-inhibitory concentrations of macrolides can be challenged by horizontal gene transfer. Yichen Ding et al. identify a novel integrative and conjugative element that confers Pseudomonas aeruginosa with resistance to carbapenem, the last-resort drug for susceptable Gram-negative bacterial infections. This study also shows how antivirulence treatment for P. aeruginosainfections can be challenged by horizontal gene transfer.
Collapse
|
9
|
McCarron A, Donnelley M, Parsons D. Airway disease phenotypes in animal models of cystic fibrosis. Respir Res 2018; 19:54. [PMID: 29609604 PMCID: PMC5879563 DOI: 10.1186/s12931-018-0750-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/13/2018] [Indexed: 12/20/2022] Open
Abstract
In humans, cystic fibrosis (CF) lung disease is characterised by chronic infection, inflammation, airway remodelling, and mucus obstruction. A lack of pulmonary manifestations in CF mouse models has hindered investigations of airway disease pathogenesis, as well as the development and testing of potential therapeutics. However, recently generated CF animal models including rat, ferret and pig models demonstrate a range of well characterised lung disease phenotypes with varying degrees of severity. This review discusses the airway phenotypes of currently available CF animal models and presents potential applications of each model in airway-related CF research.
Collapse
Affiliation(s)
- Alexandra McCarron
- Adelaide Medical School, Discipline of Paediatrics, University of Adelaide, Adelaide, SA, Australia. .,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, Adelaide, SA, Australia. .,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia.
| | - Martin Donnelley
- Adelaide Medical School, Discipline of Paediatrics, University of Adelaide, Adelaide, SA, Australia.,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| | - David Parsons
- Adelaide Medical School, Discipline of Paediatrics, University of Adelaide, Adelaide, SA, Australia.,Department of Respiratory and Sleep Medicine, Women's and Children's Hospital, Adelaide, SA, Australia.,Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia
| |
Collapse
|
10
|
PA5470 Counteracts Antimicrobial Effect of Azithromycin by Releasing Stalled Ribosome in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2018; 62:AAC.01867-17. [PMID: 29203495 DOI: 10.1128/aac.01867-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 11/23/2017] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa causes various acute and chronic infections in humans. Treatment with azithromycin (AZM) has been shown to benefit patients with chronic P. aeruginosa infections. By binding to the exit tunnel of the 50S ribosome, AZM causes ribosome stalling and depletion of the intracellular tRNA pool. It has been shown that AZM is able to kill stationary-phase P. aeruginosa cells and repress quorum sensing-regulated virulence factors as well as swarming motility. In P. aeruginosa, the PA5470 gene encodes a putative peptide chain release factor whose expression is highly induced by macrolide antibiotics. However, its function remains unknown. Here, we found that overexpression of PA5470 increased bacterial tolerance against AZM and alleviated the repression of swarming motility. Ribosome pulldown assays revealed that PA5470 contributes to the release of ribosome stalled by AZM. We further demonstrate that overexpression of PA5470 counteracts AZM-mediated repression of the translation of the quorum sensing regulator RhlR. Overall, our results revealed a novel role of PA5470 in the bacterial response to AZM.
Collapse
|
11
|
Chalmers JD. Macrolide resistance in Pseudomonas aeruginosa: implications for practice. Eur Respir J 2017; 49:49/5/1700689. [PMID: 28526802 DOI: 10.1183/13993003.00689-2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 04/03/2017] [Indexed: 11/05/2022]
Affiliation(s)
- James D Chalmers
- Division of Molecular and Clinical Medicine, University of Dundee, Dundee, UK
| |
Collapse
|
12
|
Leal T, Bergamini G, Huaux F, Panin N, Noel S, Dhooghe B, Haaf JB, Mauri P, Motta S, Di Silvestre D, Melotti P, Sorio C. Azithromycin Attenuates Pseudomonas-Induced Lung Inflammation by Targeting Bacterial Proteins Secreted in the Cultured Medium. Front Immunol 2016; 7:499. [PMID: 27895643 PMCID: PMC5108761 DOI: 10.3389/fimmu.2016.00499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/26/2016] [Indexed: 12/20/2022] Open
Abstract
Background Pseudomonas aeruginosa airway infections are a major cause of morbidity and mortality in patients with cystic fibrosis (CF). Azithromycin improves the related clinical outcomes, but its mechanisms of action remain poorly understood. We tested the hypothesis that azithromycin downregulates P. aeruginosa-induced pro-inflammatory responses by modifying release of bacterial proteins. Methods We monitored inflammatory markers in lungs of CF mutant mice and their littermate controls in response to conditioned media (CM) collected from the reference P. aeruginosa PAO1 strain cultured in the presence or in the absence of azithromycin. A mass spectrometry-based proteomic approach was applied to examine whether the macrolide elicits a differential release of bacterial proteins. Results CM collected from azithromycin-untreated PAO1 cultures induced powerful pro-inflammatory neutrophil-dominated responses. Azithromycin attenuated the responses, mainly of macrophage chemoattractant protein-1, tumor necrosis factor-α, and interferon-γ, in CF but not in wild-type mice. Proteomic analysis showed that azithromycin upregulated an array of bacterial proteins including those associated with regulation of immune functions and with repair and resolution of inflammatory responses like the chaperone DnaK and the S-adenosylmethionine synthase, while it downregulated the extracellular heme acquisition protein HasA and the catalytic enzyme lysylendopeptidase. Conclusion Supernatants collected from cultures of the bacterial strain PAO1 represent a novel experimental model to trigger in vivo lung inflammatory responses that should be closer to those obtained with live bacteria, but without bacterial infection. Combined with a bactericidal effect, complex regulation of bacterial innate immune and metabolic factors released in the cultured medium by the action of the macrolide can contribute to its anti-inflammatory effects.
Collapse
Affiliation(s)
- Teresinha Leal
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Gabriella Bergamini
- Cystic Fibrosis Translational Research Laboratory "D. Lissandrini", Department of Medicine, Division of General Pathology, University of Verona, Verona, Italy; Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy
| | - François Huaux
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Nadtha Panin
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Sabrina Noel
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Barbara Dhooghe
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Jeremy B Haaf
- Louvain Centre for Toxicology and Applied Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium
| | - Pierluigi Mauri
- Institute for Biomedical Technologies (ITB-CNR), Segrate , Milan , Italy
| | - Sara Motta
- Institute for Biomedical Technologies (ITB-CNR), Segrate , Milan , Italy
| | - Dario Di Silvestre
- Institute for Biomedical Technologies (ITB-CNR), Segrate , Milan , Italy
| | - Paola Melotti
- Cystic Fibrosis Center, Azienda Ospedaliera Universitaria Integrata di Verona , Verona , Italy
| | - Claudio Sorio
- Cystic Fibrosis Translational Research Laboratory "D. Lissandrini", Department of Medicine, Division of General Pathology, University of Verona , Verona , Italy
| |
Collapse
|
13
|
Tan H, Zhang L, Weng Y, Chen R, Zhu F, Jin Y, Cheng Z, Jin S, Wu W. PA3297 Counteracts Antimicrobial Effects of Azithromycin in Pseudomonas aeruginosa. Front Microbiol 2016; 7:317. [PMID: 27014238 PMCID: PMC4792872 DOI: 10.3389/fmicb.2016.00317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/29/2016] [Indexed: 01/08/2023] Open
Abstract
Pseudomonas aeruginosa causes acute and chronic infections in human. Its increasing resistance to antibiotics requires alternative treatments that are more effective than available strategies. Among the alternatives is the unconventional usage of conventional antibiotics, of which the macrolide antibiotic azithromycin (AZM) provides a paradigmatic example. AZM therapy is associated with a small but consistent improvement in respiratory function of cystic fibrosis patients suffering from chronic P. aeruginosa infection. Besides immunomodulating activities, AZM represses bacterial genes involved in virulence, quorum sensing, biofilm formation, and motility, all of which are due to stalling of ribosome and depletion of cellular tRNA pool. However, how P. aeruginosa responds to and counteracts the effects of AZM remain elusive. Here, we found that deficiency of PA3297, a gene encoding a DEAH-box helicase, intensified AZM-mediated bacterial killing, suppression of pyocyanin production and swarming motility, and hypersusceptibility to hydrogen peroxide. We demonstrated that expression of PA3297 is induced by the interaction between AZM and ribosome. Importantly, mutation of PA3297 resulted in elevated levels of unprocessed 23S-5S rRNA in the presence of AZM, which might lead to increased susceptibility to AZM-mediated effects. Our results revealed one of the bacterial responses in counteracting the detrimental effects of AZM.
Collapse
Affiliation(s)
- Hao Tan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Lu Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Yuding Weng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Ronghao Chen
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Feng Zhu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Shouguang Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, GainesvilleFL, USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| |
Collapse
|
14
|
Swatton JE, Davenport PW, Maunders EA, Griffin JL, Lilley KS, Welch M. Impact of Azithromycin on the Quorum Sensing-Controlled Proteome of Pseudomonas aeruginosa. PLoS One 2016; 11:e0147698. [PMID: 26808156 PMCID: PMC4726577 DOI: 10.1371/journal.pone.0147698] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/07/2016] [Indexed: 12/03/2022] Open
Abstract
The macrolide antibiotic, azithromycin (AZM), has been reported to improve the clinical outcome of cystic fibrosis patients, many of whom are chronically-infected with Pseudomonas aeruginosa. However, the highest clinically-achievable concentrations of this drug are well-below the minimum inhibitory concentration for P. aeruginosa, raising the question of why AZM exhibits therapeutic activity. One possibility that has been raised by earlier studies is that AZM inhibits quorum sensing (QS) by P. aeruginosa. To explicitly test this hypothesis the changes brought about by AZM treatment need to be compared with those associated with specific QS mutants grown alongside in the same growth medium, but this has not been done. In this work, we used quantitative 2D-difference gel electrophoresis and 1H-NMR spectroscopy footprint analysis to examine whether a range of clinically-relevant AZM concentrations elicited proteomic and metabolomic changes in wild-type cultures that were similar to those seen in cultures of defined QS mutants. Consistent with earlier reports, over half of the AZM-induced spot changes on the 2D gels were found to affect QS-regulated proteins. However, AZM modulated very few protein spots overall (compared with QS) and collectively, these modulated proteins comprised only a small fraction (12-13%) of the global QS regulon. We conclude that AZM perturbs a sub-regulon of the QS system but does not block QS per se. Reinforcing this notion, we further show that AZM is capable of attenuating virulence factor production in another Gram-negative species that secretes copious quantities of exoenzymes (Serratia marcescens), even in the absence of a functional QS system.
Collapse
Affiliation(s)
- J. E. Swatton
- Department of Biochemistry, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United Kingdom
| | - P. W. Davenport
- Department of Biochemistry, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
- Department of Pathology, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom
| | - E. A. Maunders
- Department of Biochemistry, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - J. L. Griffin
- Department of Biochemistry, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
- MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, United Kingdom
| | - K. S. Lilley
- Cambridge Centre for Proteomics, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - M. Welch
- Department of Biochemistry, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| |
Collapse
|
15
|
Imperi F, Leoni L, Visca P. Antivirulence activity of azithromycin in Pseudomonas aeruginosa. Front Microbiol 2014; 5:178. [PMID: 24795709 PMCID: PMC4001013 DOI: 10.3389/fmicb.2014.00178] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 03/31/2014] [Indexed: 11/13/2022] Open
Abstract
Antibiotics represent our bulwark to combat bacterial infections, but the spread of antibiotic resistance compromises their clinical efficacy. Alternatives to conventional antibiotics are urgently needed in order to complement the existing antibacterial arsenal. The macrolide antibiotic azithromycin (AZM) provides a paradigmatic example of an "unconventional" antibacterial drug. Besides its growth-inhibiting activity, AZM displays potent anti-inflammatory properties, as well as antivirulence activity on some intrinsically resistant bacteria, such as Pseudomonas aeruginosa. In this bacterium, the antivirulence activity of AZM mainly relies on its ability to interact with the ribosome, resulting in direct and/or indirect repression of specific subsets of genes involved in virulence, quorum sensing, biofilm formation, and intrinsic antibiotic resistance. Both clinical experience and clinical trials have shown the efficacy of AZM in the treatment of chronic pulmonary infections caused by P. aeruginosa. The aim of this review is to combine results from laboratory studies with evidence from clinical trials in order to unify the information on the in vivo mode of action of AZM in P. aeruginosa infection.
Collapse
Affiliation(s)
- Francesco Imperi
- Pasteur Institute-Cenci Bolognetti Foundation and Department of Biology and Biotechnology “C. Darwin”, “Sapienza” University of RomeRome, Italy
| | - Livia Leoni
- Department of Sciences, “Roma Tre” UniversityRome, Italy
| | - Paolo Visca
- Department of Sciences, “Roma Tre” UniversityRome, Italy
| |
Collapse
|
16
|
Parnham MJ, Erakovic Haber V, Giamarellos-Bourboulis EJ, Perletti G, Verleden GM, Vos R. Azithromycin: mechanisms of action and their relevance for clinical applications. Pharmacol Ther 2014; 143:225-45. [PMID: 24631273 DOI: 10.1016/j.pharmthera.2014.03.003] [Citation(s) in RCA: 367] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 03/04/2014] [Indexed: 01/02/2023]
Abstract
Azithromycin is a macrolide antibiotic which inhibits bacterial protein synthesis, quorum-sensing and reduces the formation of biofilm. Accumulating effectively in cells, particularly phagocytes, it is delivered in high concentrations to sites of infection, as reflected in rapid plasma clearance and extensive tissue distribution. Azithromycin is indicated for respiratory, urogenital, dermal and other bacterial infections, and exerts immunomodulatory effects in chronic inflammatory disorders, including diffuse panbronchiolitis, post-transplant bronchiolitis and rosacea. Modulation of host responses facilitates its long-term therapeutic benefit in cystic fibrosis, non-cystic fibrosis bronchiectasis, exacerbations of chronic obstructive pulmonary disease (COPD) and non-eosinophilic asthma. Initial, stimulatory effects of azithromycin on immune and epithelial cells, involving interactions with phospholipids and Erk1/2, are followed by later modulation of transcription factors AP-1, NFκB, inflammatory cytokine and mucin release. Delayed inhibitory effects on cell function and high lysosomal accumulation accompany disruption of protein and intracellular lipid transport, regulation of surface receptor expression, of macrophage phenotype and autophagy. These later changes underlie many immunomodulatory effects of azithromycin, contributing to resolution of acute infections and reduction of exacerbations in chronic airway diseases. A sub-group of post-transplant bronchiolitis patients appears to be sensitive to azithromycin, as may be patients with severe sepsis. Other promising indications include chronic prostatitis and periodontitis, but weak activity in malaria is unlikely to prove crucial. Long-term administration of azithromycin must be balanced against the potential for increased bacterial resistance. Azithromycin has a very good record of safety, but recent reports indicate rare cases of cardiac torsades des pointes in patients at risk.
Collapse
Affiliation(s)
- Michael J Parnham
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Project Group Translational Medicine and Pharmacology, Frankfurt am Main, Germany; Institute of Pharmacology for Life Scientists, Goethe University Frankfurt, Frankfurt am Main, Germany; Institute of Clinical Pharmacology, Goethe University Frankfurt, Frankfurt am Main, Germany.
| | | | - Evangelos J Giamarellos-Bourboulis
- 4th Department of Internal Medicine, University of Athens, Medical School, Athens, Greece; Integrated Research and Treatment Center, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.
| | - Gianpaolo Perletti
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto A., Varese, Italy; Department of Basic Medical Sciences, Ghent University, Ghent, Belgium.
| | - Geert M Verleden
- Respiratory Division, Lung Transplantation Unit, University Hospitals Leuven and Department of Clinical and Experimental Medicine, KU Leuven, Belgium.
| | - Robin Vos
- Respiratory Division, Lung Transplantation Unit, University Hospitals Leuven and Department of Clinical and Experimental Medicine, KU Leuven, Belgium.
| |
Collapse
|
17
|
Döring G, Bragonzi A, Paroni M, Aktürk FF, Cigana C, Schmidt A, Gilpin D, Heyder S, Born T, Smaczny C, Kohlhäufl M, Wagner TOF, Loebinger MR, Bilton D, Tunney MM, Elborn JS, Pier GB, Konstan MW, Ulrich M. BIIL 284 reduces neutrophil numbers but increases P. aeruginosa bacteremia and inflammation in mouse lungs. J Cyst Fibros 2013; 13:156-63. [PMID: 24183915 DOI: 10.1016/j.jcf.2013.10.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/14/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND A clinical study to investigate the leukotriene B(4) (LTB(4))-receptor antagonist BIIL 284 in cystic fibrosis (CF) patients was prematurely terminated due to a significantly increased risk of adverse pulmonary events. We aimed to establish the effect of BIIL284 in models of Pseudomonas aeruginosa lung infection, thereby contributing to a better understanding of what could have led to adverse pulmonary events in CF patients. METHODS P. aeruginosa DNA in the blood of CF patients during and after acute pulmonary exacerbations and in stable patients with non-CF bronchiectasis (NCFB) and healthy individuals was assessed by PCR. The effect of BIIL 284 treatment was tested in an agar bead murine model of P. aeruginosa lung infection. Bacterial count and inflammation were evaluated in lung and other organs. RESULTS Most CF patients (98%) and all patients with NCFB and healthy individuals had negative P. aeruginosa DNA in their blood. Similarly, the P. aeruginosa-infected mice showed bacterial counts in the lung but not in the blood or spleen. BIIL 284 treatment decreased pulmonary neutrophils and increased P. aeruginosa numbers in mouse lungs leading to significantly higher bacteremia rates and lung inflammation compared to placebo treated animals. CONCLUSIONS Decreased airway neutrophils induced lung proliferation and severe bacteremia in a murine model of P. aeruginosa lung infection. These data suggest that caution should be taken when administering anti-inflammatory compounds to patients with bacterial infections.
Collapse
Affiliation(s)
- Gerd Döring
- Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Alessandra Bragonzi
- Infection and Cystic Fibrosis Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy.
| | - Moira Paroni
- Infection and Cystic Fibrosis Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
| | - Firdevs-Fatma Aktürk
- Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Cristina Cigana
- Infection and Cystic Fibrosis Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milano, Italy
| | - Annika Schmidt
- Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | | | - Susanne Heyder
- Klinik Schillerhöhe, Robert-Bosch Krankenhaus, Gerlingen, Germany
| | - Torsten Born
- Universitätsklinikum Frankfurt, Frankfurt, Germany
| | | | - Martin Kohlhäufl
- Klinik Schillerhöhe, Robert-Bosch Krankenhaus, Gerlingen, Germany
| | | | | | | | | | | | - Gerald B Pier
- Division of infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael W Konstan
- Case Western Reserve University, UH Rainbow Babies & Children's Hospital, Cleveland, OH, USA
| | - Martina Ulrich
- Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| |
Collapse
|
18
|
Antibacterial and immunomodulatory properties of azithromycin treatment implications for periodontitis. Inflammopharmacology 2013; 21:321-38. [DOI: 10.1007/s10787-012-0165-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 11/30/2012] [Indexed: 12/19/2022]
|
19
|
Zhou X, Zhang Y, Li Y, Hao X, Liu X, Wang Y. Azithromycin synergistically enhances anti-proliferative activity of vincristine in cervical and gastric cancer cells. Cancers (Basel) 2012; 4:1318-32. [PMID: 24213508 PMCID: PMC3712727 DOI: 10.3390/cancers4041318] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/16/2012] [Accepted: 11/30/2012] [Indexed: 01/04/2023] Open
Abstract
In this study, the anti-proliferative and anticancer activity of azithromycin (AZM) was examined. In the presence of AZM, cell growth was inhibited more effectively in Hela and SGC-7901 cancer cells, relative to transformed BHK-21 cells. The respective 50% inhibition of cell growth (IC50) values for Hela, SGC-7901 and BHK-21 were 15.66, 26.05 and 91.00 µg/mL at 72 h post incubation, indicative of a selective cytotoxicity against cancer cells. Cell apoptosis analysis using Hoechst nuclear staining and annexin V-FITC binding assay further demonstrated that AZM was capable of inducing apoptosis in both cancer cells and transformed cells. The apoptosis induced by AZM was partly through a caspase-dependent mechanism with an up-regulation of apoptotic protein cleavage PARP and caspase-3 products, as well as a down-regulation of anti-apoptotic proteins, Mcl-1, bcl-2 and bcl-X1. More importantly, a combination of AZM and a low dose of the common anti-cancer chemotherapeutic agent vincristine (VCR), produced a selectively synergistic effect on apoptosis of Hela and SGC-7901 cells, but not BHK-21 cells. In the presence of 12.50 μg/mL of VCR, the respective IC50 values of Hela, SGC-7901 and BHK-21 cells to AZM were reduced to 9.47 µg/mL, 8.43 µg/mL and 40.15 µg/mL at 72 h after the incubation, suggesting that the cytotoxicity of AZM had a selective anti-cancer effect on cancer over transformed cells in vitro. These results imply that AZM may be a potential anticancer agent for use in chemotherapy regimens, and it may minimize side effects via reduction of dosage and enhancing the effectiveness common chemotherapeutic drugs.
Collapse
Affiliation(s)
- Xuezhang Zhou
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
| | - Yuyan Zhang
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
| | - Yong Li
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
| | - Xiujing Hao
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
| | - Xiaoming Liu
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
- Authors to whom correspondence should be addressed; E-Mails: (X.L.); (Y.W.); Tel.: +86-951-206-2033 (Y.W.); Fax: +86-951-206-2699 (Y.W.)
| | - Yujiong Wang
- Key Laboratory of the Ministry of Education for the Conservation and Utilization of Special Biological Resources of Western China, Yinchuan 750021, Ningxia, China; E-Mails: (X.Z.); (Y.Z.); (Y.L.); (X.H.)
- College of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China
- Authors to whom correspondence should be addressed; E-Mails: (X.L.); (Y.W.); Tel.: +86-951-206-2033 (Y.W.); Fax: +86-951-206-2699 (Y.W.)
| |
Collapse
|
20
|
Zarogoulidis P, Papanas N, Kioumis I, Chatzaki E, Maltezos E, Zarogoulidis K. Macrolides: from in vitro anti-inflammatory and immunomodulatory properties to clinical practice in respiratory diseases. Eur J Clin Pharmacol 2011; 68:479-503. [PMID: 22105373 DOI: 10.1007/s00228-011-1161-x] [Citation(s) in RCA: 187] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 10/25/2011] [Indexed: 12/12/2022]
Abstract
BACKGROUND Macrolides have long been recognised to exert immunomodulary and anti-inflammatory actions. They are able to suppress the "cytokine storm" of inflammation and to confer an additional clinical benefit through their immunomodulatory properties. METHODS A search of electronic journal articles was performed using combinations of the following keywords: macrolides, COPD, asthma, bronchitis, bronchiolitis obliterans, cystic fibrosis, immunomodulation, anti-inflammatory effect, diabetes, side effects and systemic diseases. RESULTS Macrolide effects are time- and dose-dependent, and the mechanisms underlying these effects remain incompletely understood. Both in vitro and in vivo studies have provided ample evidence of their immunomodulary and anti-inflammatory actions. Importantly, this class of antibiotics is efficacious with respect to controlling exacerbations of underlying respiratory problems, such as cystic fibrosis, asthma, bronchiectasis, panbrochiolitis and cryptogenic organising pneumonia. Macrolides have also been reported to reduce airway hyper-responsiveness and improve pulmonary function. CONCLUSION This review provides an overview on the properties of macrolides (erythromycin, clarithromycin, roxithromycin, azithromycin), their efficacy in various respiratory diseases and their adverse effects.
Collapse
Affiliation(s)
- P Zarogoulidis
- Pulmonary Department, G. Papanikolaou Hospital, Aristotle University of Thessaloniki, Thessaloniki 57010, Greece.
| | | | | | | | | | | |
Collapse
|
21
|
Pichereau S, Moran JJM, Hayney MS, Shukla SK, Sakoulas G, Rose WE. Concentration-dependent effects of antimicrobials on Staphylococcus aureus toxin-mediated cytokine production from peripheral blood mononuclear cells. J Antimicrob Chemother 2011; 67:123-9. [PMID: 21980070 DOI: 10.1093/jac/dkr417] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Toxins contribute to the pathogenicity of Staphylococcus aureus infections by inducing a dysregulated inflammatory response. This study evaluated the impact of anti-staphylococcal antibiotic exposures over an increasing concentration range on cytokine production from peripheral blood mononuclear cells (PBMCs) after S. aureus toxin exposures. METHODS Human PBMCs were suspended in complete Roswell Park Memorial Institute (RPMI) 1640 medium with 10% fetal bovine serum at 10(6) cells/mL with 100 ng/mL S. aureus toxic shock syndrome toxin-1 (TSST-1), staphylococcal enterotoxin A (SEA), α-toxin or Panton-Valentine leucocidin (PVL). Vancomycin, trimethoprim/sulfamethoxazole, tigecycline, daptomycin, linezolid, clindamycin and azithromycin were added at a concentration range of 0.5-100 mg/L. Cytokine [interleukin-1β (IL-1β), IL-6, IL-8, interferon-γ (IFN-γ) and tumour necrosis factor-α (TNF-α)] concentrations were measured in duplicate by ELISA following exposure and were compared with response with toxin alone. RESULTS At concentrations approximating serum C(max), tigecycline decreased IL-6 by 52%-57% and IFN-γ production by 43%-53% compared with toxin alone (P ≤ 0.05) and linezolid inhibited TNF-α by 12%-35% and IL-8 by 25%-42% (P ≤ 0.02). However, trimethoprim/sulfamethoxazole increased TNF-α and IL-8 production (P = 0.002). Clindamycin, daptomycin, vancomycin and azithromycin had no consistent significant effect at approximate serum C(max) concentrations. All antibiotics had a concentration-dependent effect on cytokine production, with tigecycline, clindamycin and trimethoprim/sulfamethoxazole being the most potent inhibitors of cytokine production at concentrations exceeding 25 mg/L. CONCLUSIONS S. aureus toxins stimulate production of inflammatory cytokines in PBMCs. Antimicrobials with high tissue penetration, including tigecycline, clindamycin, trimethoprim/sulfamethoxazole and linezolid, reduced cytokine production, which, along with their antimicrobial effects, may have importance in the therapeutic outcome of severe infections.
Collapse
Affiliation(s)
- Solen Pichereau
- Pharmacy Practice Division, University of Wisconsin-Madison School of Pharmacy, Madison, WI 53705, USA
| | | | | | | | | | | |
Collapse
|
22
|
Hodges CA, Grady BR, Mishra K, Cotton CU, Drumm ML. Cystic fibrosis growth retardation is not correlated with loss of Cftr in the intestinal epithelium. Am J Physiol Gastrointest Liver Physiol 2011; 301:G528-36. [PMID: 21659619 PMCID: PMC3174541 DOI: 10.1152/ajpgi.00052.2011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Maldigestion due to exocrine pancreatic insufficiency leads to intestinal malabsorption and consequent malnutrition, a mechanism proposed to cause growth retardation associated with cystic fibrosis (CF). However, although enzyme replacement therapy combined with increased caloric intake improves weight gain, the effect on stature is not significant, suggesting that growth retardation has a more complex etiology. Mouse models of CF support this, since these animals do not experience exocrine pancreatic insufficiency yet are growth impaired. Cftr absence from the intestinal epithelium has been suggested as a primary source of growth retardation in CF mice, a concept we directly tested by generating mouse models with Cftr selectively inactivated or restored in intestinal epithelium. The relationship between growth and functional characteristics of the intestines, including transepithelial electrophysiology, incidence of intestinal obstruction, and histopathology, were assessed. Absence of Cftr exclusively from intestinal epithelium resulted in loss of cAMP-stimulated short-circuit current, goblet cell hyperplasia, and occurrence of intestinal obstructions but only slight and transient impaired growth. In contrast, specifically restoring Cftr to the intestinal epithelium resulted in restoration of ion transport and completely protected against obstruction and histopathological anomalies, but growth was indistinguishable from CF mice. These results indicate that absence of Cftr in the intestinal epithelium is an important contributor to the intestinal obstruction phenotype in CF but does not correlate with the observed growth reduction in CF.
Collapse
Affiliation(s)
| | | | | | | | - Mitchell L. Drumm
- Departments of 1Pediatrics, ,3Genetics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| |
Collapse
|
23
|
Pseudomonas aeruginosa suppresses interferon response to rhinovirus infection in cystic fibrosis but not in normal bronchial epithelial cells. Infect Immun 2011; 79:4131-45. [PMID: 21825067 DOI: 10.1128/iai.05120-11] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Despite increased morbidity associated with secondary respiratory viral infections in cystic fibrosis (CF) patients with chronic Pseudomonas aeruginosa infection, the underlying mechanisms are not well understood. Here, we investigated the effect of P. aeruginosa infection on the innate immune responses of bronchial epithelial cells to rhinovirus (RV) infection. CF cells sequentially infected with mucoid P. aeruginosa (MPA) and RV showed lower levels of interferons (IFNs) and higher viral loads than those of RV-infected cells. Unlike results for CF cells, normal bronchial epithelial cells coinfected with MPA/RV showed higher IFN expression than RV-infected cells. In both CF and normal cells, the RV-stimulated IFN response requires phosphorylation of Akt and interferon response factor 3 (IRF3). Preinfection with MPA inhibited RV-stimulated Akt phosphorylation and decreased IRF3 phosphorylation in CF cells but not in normal cells. Compared to normal, unstimulated CF cells or normal cells treated with CFTR inhibitor showed increased reactive oxygen species (ROS) production. Treatment of CF cells with antioxidants prior to MPA infection partially reversed the suppressive effect of MPA on the RV-stimulated IFN response. Together, these results suggest that MPA preinfection inhibits viral clearance by suppressing the antiviral response particularly in CF cells but not in normal cells. Further, increased oxidative stress in CF cells appears to modulate the innate immune responses to coinfection.
Collapse
|
24
|
Goldberg JB, Ganesan S, Comstock AT, Zhao Y, Sajjan US. Cable pili and the associated 22 kDa adhesin contribute to Burkholderia cenocepacia persistence in vivo. PLoS One 2011; 6:e22435. [PMID: 21811611 PMCID: PMC3141045 DOI: 10.1371/journal.pone.0022435] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 06/27/2011] [Indexed: 01/02/2023] Open
Abstract
Background Infection by Burkholderia cenocepacia in cystic fibrosis (CF) patients is associated with poor clinical prognosis. Previously, we demonstrated that one of the highly transmissible strains, BC7, expresses cable pili and the associated 22 kDa adhesin, both of which contribute to BC7 binding to airway epithelial cells. However, the contribution of these factors to induce inflammation and bacterial persistence in vivo is not known. Methodology/Principal Findings Wild-type BC7 stimulated higher IL-8 responses than the BC7 cbl and BC7 adhA mutants in both CF and normal bronchial epithelial cells. To determine the role of cable pili and the associated adhesin, we characterized a mouse model of B. cenocepacia, where BC7 are suspended in Pseudomonas aeruginosa alginate. C57BL/6 mice were infected intratracheally with wild-type BC7 suspended in either alginate or PBS and were monitored for lung bacterial load and inflammation. Mice infected with BC7 suspended in PBS completely cleared the bacteria by 3 days and resolved the inflammation. In contrast, mice infected with BC7 suspended in alginate showed persistence of bacteria and moderate lung inflammation up to 5 days post-infection. Using this model, mice infected with the BC7 cbl and BC7 adhA mutants showed lower bacterial loads and mild inflammation compared to mice infected with wild-type BC7. Complementation of the BC7 cblS mutation in trans restored the capacity of this strain to persist in vivo. Immunolocalization of bacteria revealed wild-type BC7 in both airway lumen and alveoli, while the BC7 cbl and BC7 adhA mutants were found mainly in airway lumen and peribronchiolar region. Conclusions and Significance B. cenocepacia suspended in alginate can be used to determine the capacity of bacteria to persist and cause lung inflammation in normal mice. Both cable pili and adhesin contribute to BC7-stimulated IL-8 response in vitro, and BC7 persistence and resultant inflammation in vivo.
Collapse
Affiliation(s)
- Joanna B. Goldberg
- Department of Microbiology, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Shyamala Ganesan
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Adam T. Comstock
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ying Zhao
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Uma S. Sajjan
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
25
|
Abstract
Inflammation is a major component of the vicious cycle characterizing cystic fibrosis (CF) pulmonary disease. If untreated, this inflammatory process irreversibly damages the airways, leading to bronchiectasis and ultimately respiratory failure. Anti-inflammatory drugs for CF lung disease appear to have beneficial effects on disease progression. These agents include oral corticosteroids and ibuprofen, as well as azithromycin, which, in addition to its antimicrobial effects, also possess anti-inflammatory properties. Inhaled corticosteroids, antioxidants, nutritional supplements, and protease inhibitors have a limited impact on the disease. Adverse effects limit therapy with oral corticosteroids and ibuprofen. Azithromycin appears to be safe and effective, and is thus the most promising anti-inflammatory therapy available for patients with CF. Pharmacologic therapy with anti-inflammatory agents should be started early in the disease course, before extensive irreversible lung damage has occurred. To optimize anti-inflammatory therapy, it is necessary to understand the mechanism of action of these agents in the CF lung, to determine which of these agents would provide the most benefit to patients with CF, and to determine which therapies should be initiated at what age or stage of lung disease.
Collapse
Affiliation(s)
- Tacjana Pressler
- CF Centre Copenhagen, Department of Paediatrics, University Hospital Rigshospitalet, Copenhagen, Denmark.
| |
Collapse
|
26
|
Hassan HE, Othman AA, Eddington ND, Duffy L, Xiao L, Waites KB, Kaufman DA, Fairchild KD, Terrin ML, Viscardi RM. Pharmacokinetics, safety, and biologic effects of azithromycin in extremely preterm infants at risk for ureaplasma colonization and bronchopulmonary dysplasia. J Clin Pharmacol 2010; 51:1264-75. [PMID: 21098694 DOI: 10.1177/0091270010382021] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Ureaplasma spp. respiratory tract colonization is a significant risk factor for bronchopulmonary dysplasia (BPD), a chronic lung disorder in preterm infants. As an initial step preparatory to future clinical trials to evaluate the clinical efficacy of azithromycin to prevent BPD, the authors characterized the pharmacokinetics, safety, and biological effects of a single intravenous dose of azithromycin (10 mg/kg) in preterm neonates (n = 12) 24 to 28 weeks gestation at risk for Ureaplasma infection and BPD. A 2-compartment structural model with the clearance and volume of peripheral compartment (V2) allometrically scaled on body weight (WT) best described the pharmacokinetics of azithromycin in preterm neonates. The estimated parameters were clearance [0.18 L/h × WT(kg)(0.75)], intercompartmental clearance [1.0 L/h], volume of distribution of central compartment [0.93 L], and V2 [14.2 L × WT(kg)]. There were no serious adverse events attributed to azithromycin. A single dose of azithromycin did not suppress inflammatory cytokines or myeloperoxidase activity in tracheal aspirates. These results demonstrated the safety of azithromycin and developed a pharmacokinetic model that is useful for future simulation-based clinical trials for eradicating Ureaplasma and preventing BPD in preterm neonates.
Collapse
Affiliation(s)
- Hazem E Hassan
- Pharmacokinetics and Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Current World Literature. Curr Opin Pulm Med 2010; 16:623-7. [DOI: 10.1097/mcp.0b013e32834006f9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
28
|
Li DQ, Zhou N, Zhang L, Ma P, Pflugfelder SC. Suppressive effects of azithromycin on zymosan-induced production of proinflammatory mediators by human corneal epithelial cells. Invest Ophthalmol Vis Sci 2010; 51:5623-9. [PMID: 20538995 DOI: 10.1167/iovs.09-4992] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE In addition to its antibiotic effects, azithromycin has been noted to have anti-inflammatory activity, particularly in the context of microbial infections. This study was conducted to explore the suppressive effects of azithromycin on the production of proinflammatory mediators by human corneal epithelial cells (HCECs) stimulated by a fungal component, zymosan. METHODS Primary HCECs were cultured from donor corneal limbal explants and grown to subconfluence. The cells were treated with toll-like receptor (TLR) 2 agonist zymosan (1-50 μg/mL) for 4 to 48 hours, with or without preincubation with azithromycin (1-50 μg/mL), TLR2 antibody, or NF-κB activation inhibitor quinazoline (NF-κB-I). The cells were subjected to total RNA extraction, reverse transcription (RT), and real-time PCR using gene expression assays. Cells treated for 48 hours were used for immunofluorescence staining and Western blot analysis, and their medium supernatants were collected for protein quantitation by immunobead assays. RESULTS The mRNA expression and protein production of proinflammatory cytokines (TNF-α and IL-1β), chemokines (IL-8 and RANTES), and matrix metalloproteinases (MMP-1, -3, and -9) by HCECs were stimulated by zymosan in a concentration-dependent manner, with peak levels noted at 4 hours. These stimulated levels of proinflammatory mediators by zymosan were significantly inhibited by TLR2 antibody, NF-κB-I, or azithromycin, which blocked zymosan-induced NF-κB activation as determined by p65 protein nuclear translocation. CONCLUSIONS These findings demonstrated that the fungal component zymosan induces proinflammatory responses through TLR2 and NF-κB signaling pathways, whereas azithromycin suppresses its stimulation by blocking NF-κB activation in HCECs, suggesting the potential efficacy of this antibiotic for treating ocular surface inflammatory disorders.
Collapse
Affiliation(s)
- De-Quan Li
- Department of Ophthalmology, Baylor College of Medicine, Ocular Surface Center, Cullen Eye Institute, Houston, Texas 77030, USA
| | | | | | | | | |
Collapse
|
29
|
Azithromycin alters macrophage phenotype and pulmonary compartmentalization during lung infection with Pseudomonas. Antimicrob Agents Chemother 2010; 54:2437-47. [PMID: 20231397 DOI: 10.1128/aac.01424-09] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Infection with mucoid strains of Pseudomonas aeruginosa in chronic inflammatory diseases of the airway is difficult to eradicate and can cause excessive inflammation. The roles of alternatively activated and regulatory subsets of macrophages in this pathophysiological process are not well characterized. We previously demonstrated that azithromycin induces an alternatively activated macrophage-like phenotype in vitro. In the present study, we tested whether azithromycin affects the macrophage activation status and migration in the lungs of P. aeruginosa-infected mice. C57BL/6 mice received daily doses of oral azithromycin and were infected intratracheally with a mucoid strain of P. aeruginosa. The properties of macrophage activation, immune cell infiltration, and markers of pulmonary inflammation in the lung interstitial and alveolar compartments were evaluated postinfection. Markers of alternative macrophage activation were induced by azithromycin treatment, including the surface expression of the mannose receptor, the upregulation of arginase 1, and a decrease in the production of proinflammatory cytokines. Additionally, azithromycin increased the number of CD11b(+) monocytes and CD4(+) T cells that infiltrated the alveolar compartment. A predominant subset of CD11b(+) cells was Gr-1 positive (Gr-1(+)), indicative of a subset of cells that has been shown to be immunoregulatory. These differences corresponded to decreases in neutrophil influx into the lung parenchyma and alteration of the characteristics of peribronchiolar inflammation without any change in the clearance of the organism. These results suggest that the immunomodulatory effects of azithromycin are associated with the induction of alternative and regulatory macrophage activation characteristics and alteration of cellular compartmentalization during infection.
Collapse
|
30
|
Pseudomonas aeruginosa alginate promotes Burkholderia cenocepacia persistence in cystic fibrosis transmembrane conductance regulator knockout mice. Infect Immun 2010; 78:984-93. [PMID: 20048042 DOI: 10.1128/iai.01192-09] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa, a major respiratory pathogen in cystic fibrosis (CF) patients, facilitates infection by other opportunistic pathogens. Burkholderia cenocepacia, which normally infects adolescent patients, encounters alginate elaborated by mucoid P. aeruginosa. To determine whether P. aeruginosa alginate facilitates B. cenocepacia infection in mice, cystic fibrosis transmembrane conductance regulator knockout mice were infected with B. cenocepacia strain BC7 suspended in either phosphate-buffered saline (BC7/PBS) or P. aeruginosa alginate (BC7/alginate), and the pulmonary bacterial load and inflammation were monitored. Mice infected with BC7/PBS cleared all of the bacteria within 3 days, and inflammation was resolved by day 5. In contrast, mice infected with BC7/alginate showed persistence of bacteria and increased cytokine levels for up to 7 days. Histological examination of the lungs indicated that there was moderate to severe inflammation and pneumonic consolidation in isolated areas at 5 and 7 days postinfection in the BC7/alginate group. Further, alginate decreased phagocytosis of B. cenocepacia by professional phagocytes both in vivo and in vitro. P. aeruginosa alginate also reduced the proinflammatory responses of CF airway epithelial cells and alveolar macrophages to B. cenocepacia infection. The observed effects are specific to P. aeruginosa alginate, because enzymatically degraded alginate or other polyuronic acids did not facilitate bacterial persistence. These observations suggest that P. aeruginosa alginate may facilitate B. cenocepacia infection by interfering with host innate defense mechanisms.
Collapse
|