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Wang Q, Wen W, Zhou L, Liu F, Ren X, Yu L, Chen H, Jiang Z. LL-37 improves sepsis-induced acute lung injury by suppressing pyroptosis in alveolar epithelial cells. Int Immunopharmacol 2024; 129:111580. [PMID: 38310763 DOI: 10.1016/j.intimp.2024.111580] [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: 11/03/2023] [Revised: 01/19/2024] [Accepted: 01/20/2024] [Indexed: 02/06/2024]
Abstract
BACKGROUND LL-37 (also known as murine CRAMP) is a human antimicrobial peptide that plays a crucial role in innate immune defence against sepsis through various mechanisms. However, its involvement in sepsis-induced lung injury remains unclear. OBJECTIVES This work investigates the impact of LL-37 on pyroptosis generated by LPS in alveolar epithelial cells. The research utilizes both in vivo and in vitro sepsis-associated acute lung injury (ALI) models to understand the underlying molecular pathways. METHODS In vivo, an acute lung injury model induced by sepsis was established by intratracheal administration of LPS in C57BL/6J mice, which were subsequently treated with low-dose CRAMP (recombinant murine cathelicidin, 2.5 mg.kg-1) and high-dose CRAMP (5.0 mg.kg-1). In vitro, pyroptosis was induced in a human alveolar epithelial cell line (A549) by stimulation with LPS and ATP. Treatment was carried out with recombinant human LL-37, or LL-37 was knocked out in A549 cells using small interfering RNA (siRNA). Subsequently, haematoxylin and eosin staining was performed to observe the histopathological changes in lung tissues in the control group and sepsis-induced lung injury group. TUNEL and PI staining were used to observe DNA fragmentation and pyroptosis in mouse lung tissues and cells in the different groups. An lactate dehydrogenase (LDH) assay was performed to measure the cell death rate. The expression levels of NLRP3, caspase1, caspase 1 p20, GSDMD, NT-GSDMD, and CRAMP were detected in mice and cells using Western blotting, qPCR, and immunohistochemistry. ELISA was used to assess the levels of interleukin (IL)-1β and IL-18 in mouse serum, bronchoalveolar lavage fluid (BALF) and lung tissue and cell culture supernatants. RESULTS The expression of NLRP3, caspase1 p20, NT-GSDMD, IL 18 and IL1β in the lung tissue of mice with septic lung injury was increased, which indicated activation of the canonical pyroptosis pathway and coincided with an increase in CRAMP expression. Treatment with recombinant CRAMP improved pyroptosis in mice with lung injury. In vitro, treatment with LPS and ATP upregulated these classic pyroptosis molecules, LL-37 knockdown exacerbated pyroptosis, and recombinant human LL-37 treatment alleviated pyroptosis in alveolar epithelial cells. CONCLUSION These findings indicate that LL-37 protects against septic lung injury by modulating the expression of classic pyroptotic pathway components, including NLRP3, caspase1, and GSDMD and downstream inflammatory factors in alveolar epithelial cells.
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Affiliation(s)
- Quanzhen Wang
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Wei Wen
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Lei Zhou
- The First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250014, China; Department of Respiratory Intensive Care Unit, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Fen Liu
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Xiaoxu Ren
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Lifeng Yu
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China
| | - Huanqin Chen
- Department of Gerontology, Qilu Hospital, Shandong University, Jinan, 250012 Shandong, China
| | - Zhiming Jiang
- Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250014, China.
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Usmani J, Wasim M, Ansari MN, Hassan MJ, Sharma M, Ahmad R. Potential therapeutic effect of Carica papaya leaves extract on immune response, biochemical and hematological mechanisms on cecal ligation and puncture model of sepsis in rats: an in vivo study. 3 Biotech 2023; 13:151. [PMID: 37131965 PMCID: PMC10148938 DOI: 10.1007/s13205-023-03567-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 04/19/2023] [Indexed: 05/04/2023] Open
Abstract
Antibiotics and immunotherapies possess unavoidable adverse effects that hinder sepsis management. Herbal drugs have demonstrated potential immunomodulatory properties vital for sepsis treatment. We hypothesized in the present study that the use of Carica papaya leaves extract had the potential to improve survival and modulate immune cytokine release during sepsis. Animals were subjected to cecal ligation and puncture (CLP) to induce sepsis. Septic rats divided into 10 groups received ethanol extract of C. papaya leaves (50 and 100 mg/kg), imipenem (120 mg/kg) and cyclophosphamide (CP, 10 mg/kg). To investigate the immunomodulatory potentials of EE, cytokine levels like interleukin (IL-6), tumor necrosis factor (TNF-α), and IL-10 along with hematological and biochemical parameters were analyzed. Our results exhibited improved survival rates concerning ethanol extract treatment alone and in combination with imipenem and CP (100%) as compared to the CLP group (33.3%) on day 7 post-surgery. The combination treatment of ethanol extract with imipenem and CP significantly (P < 0.001) ameliorated cytokine levels and hematological and biochemical parameters in septic rats. A histopathological examination suggested improved liver and kidney tissue condition after combination treatment as compared to the CLP group. Therefore, it was concluded that combination therapy of extract with imipenem and CP improved survival rates and marked immunomodulatory potential in septic rats compared to monotherapy. The findings suggested the use of a mixture of these drugs in clinical settings to treat sepsis.
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Affiliation(s)
- Juveria Usmani
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062 India
| | - Mohd Wasim
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062 India
| | - Mohd Nazam Ansari
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, 11942 Kingdom of Saudi Arabia
| | - Mohammed Jaseem Hassan
- Department of Pathology, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh 202002 India
| | - Manju Sharma
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062 India
| | - Razi Ahmad
- Department of Pharmacology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, 110062 India
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Our Experience over 20 Years: Antimicrobial Peptides against Gram Positives, Gram Negatives, and Fungi. Pharmaceutics 2022; 15:pharmaceutics15010040. [PMID: 36678669 PMCID: PMC9862542 DOI: 10.3390/pharmaceutics15010040] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/04/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
Antibiotic resistance is rapidly increasing, and new anti-infective therapies are urgently needed. In this regard, antimicrobial peptides (AMPs) may represent potential candidates for the treatment of infections caused by multiresistant microorganisms. In this narrative review, we reported the experience of our research group over 20 years. We described the AMPs we evaluated against Gram-positive, Gram-negative, and fungi. In conclusion, our experience shows that AMPs can be a key option for treating multiresistant infections and overcoming resistance mechanisms. The combination of AMPs allows antibiotics and antifungals that are no longer effective to exploit the synergistic effect by restoring their efficacy. A current limitation includes poor data on human patients, the cost of some AMPs, and their safety, which is why studies on humans are needed as soon as possible.
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Escobar‐Salom M, Torrens G, Jordana‐Lluch E, Oliver A, Juan C. Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant
Gram
‐negatives. Biol Rev Camb Philos Soc 2022; 97:1005-1037. [PMID: 35043558 PMCID: PMC9304279 DOI: 10.1111/brv.12830] [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] [Received: 05/18/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.
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Affiliation(s)
- María Escobar‐Salom
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Gabriel Torrens
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Elena Jordana‐Lluch
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Antonio Oliver
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Carlos Juan
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
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Vitamin D binding protein, but not vitamin D or vitamin D-related peptides, is associated with septic shock mortality. Enferm Infecc Microbiol Clin 2019; 37:239-243. [DOI: 10.1016/j.eimc.2018.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/13/2018] [Accepted: 06/17/2018] [Indexed: 01/24/2023]
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Effect of early fluid resuscitation combined with low dose cyclophosphamide on intestinal barrier function in severe sepsis rats. Drug Deliv Transl Res 2018; 8:1254-1264. [PMID: 30112606 DOI: 10.1007/s13346-018-0573-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To investigate the effect of early fluid resuscitation on intestinal microecology in rats with severe sepsis. The severe sepsis model used was mainly cecal ligation perforation (CLP) model. Male SD rats were randomly divided into five groups: sham, CLP, CLP + normal saline (NS), CLP + cyclophosphamide (CTX), and CLP + NS + CTX. (1) The levels of IL-6, IL-10, and TNF-α in peripheral blood were measured by ELISA. (2) The expression of occludin/β-action in colonic tissue of mice was examined by Western Blot. (3) The intestinal permeability was measured by FD70 detection. (4) The length of the chorionic membrane was measured by colon histopathological staining. (5) The intestinal epithelial cell apoptosis was measured with the apoptosis index. (1) The rat model of severe sepsis was successfully replicated, and the 7-day survival rate of sepsis mice in each group was analyzed. (2) The expression level of splenic junction protein and the pathological damage in colonic tissue of the severe sepsis mice was significantly different between sham, CLP, CTX, NS, and NS + CTX (P < 0.05). The expression of tight junction protein in the NS + CTX mice was the highest, and the pathological damage was the smallest. (3) The colonic tissue apoptosis and intestinal permeability in the severe sepsis mice were compared with those of the colon tissues (P < 0.05). (4) The expression levels of IL-6, IL-10, and TNF-α in peripheral blood were significantly increased after severe sepsis (P < 0.01). The expression of IL-6 and TNF-alpha in each treatment group decreased (P < 0.05), while the expression of IL-10 in NS + CTX group increased significantly (P < 0.01). (1) We successfully replicated the rat model of severe sepsis. (2) Early fluid intervention and cyclophosphamide treatment can significantly improve the 7-day survival rate of the sepsis mice. (3) The fluid resuscitation and cyclophosphamide can delay intestinal damage to the intestinal tract barrier function and play a protective role.
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Pathological Role and Diagnostic Value of Endogenous Host Defense Peptides in Adult and Neonatal Sepsis: A Systematic Review. Shock 2018; 47:673-679. [PMID: 27941592 DOI: 10.1097/shk.0000000000000815] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Sepsis is a systemic host response to an infection leading to organ failure. This is associated with dynamic expression of endogenous host defense peptides. Dysregulation of these peptides is associated with septic morbidity and mortality. METHODS We performed a systematic search of articles indexed in PubMed, ISI Web of Knowledge, EmBase, and Scopus database from inception to October 2016. Both preclinical and clinical studies investigating the role of host defense peptides in pathogenesis and as biomarkers for sepsis were included. RESULTS Of the available literature, cathelicidin, defensin, and hepcidin are among the best-characterized peptides. These regulate immune response, and crosstalk with pyroptosis and coagulation cascades. The applicability of these peptides as septic biomarkers has been investigated in vitro and in vivo studies. However, numerous studies were based on endotoxemia without an infection, jeopardizing interpretation of the outcomes. Cathelicidin and defensin were frequently reported in adult sepsis while hepcidin in neonatal sepsis. The expression level of these peptides is significantly associated with septic condition. Most of the studies employed a cross-sectional design, precluding the establishment of a temporal relationship between candidate peptide biomarkers and sepsis. CONCLUSIONS Innate defense peptides have been insufficiently evaluated as either diagnostic or prognostic biomarkers. In the future, evaluation of host defense peptides as septic biomarkers may employ a longitudinal design and consider a panel of multiple peptides.
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Sustained tobramycin release from polyphosphate double network hydrogels. Acta Biomater 2017; 50:484-492. [PMID: 27993638 DOI: 10.1016/j.actbio.2016.12.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 12/07/2016] [Accepted: 12/13/2016] [Indexed: 11/22/2022]
Abstract
Sustained local delivery of antibiotics from a drug reservoir to treat or prevent bacterial infections can avoid many of the drawbacks of systemic administration of antibiotics. Prolonged local release of high concentrations of antibiotics may also be more effective at treating bacteria in established biofilm populations that are resistant to systemic antibiotics. A double network hydrogel comprising an organic polyphosphate pre-polymer network polymerized within a polyacrylamide network de-swelled to about 50% of its initial volume when the polyphosphate network was crosslinked with polycationic tobramycin, an aminoglycoside antibiotic. The antibiotic-loaded hydrogels contained approximately 200mg/ml of tobramycin. The hydrogels continuously released daily amounts of tobramycin above the Pseudomonas aeruginosa minimal bactericidal concentration for greater than 50days, over the pH range 6.0-8.0, and completely eradicated established P. aeruginosa biofilms within 72h in a flow cell bioreactor. The presence of physiological concentrations of Mg2+ and Ca2+ ions doubled the cumulative release over 60days. The polyphosphate hydrogels show promise as materials for sustained localized tobramycin delivery to prevent post-operative P. aeruginosa infections including infections established in biofilms. STATEMENT OF SIGNIFICANCE Polyphosphate hydrogels were loaded with high concentrations of tobramycin. The hydrogels provided sustained release of bactericidal concentrations of tobramycin for 50days, and were capable of completely eradicating P. aeruginosa in established biofilms. The hydrogels have potential for localized prevention or treatment of P. aeruginosa infections.
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Abstract
Sepsis is a complex medical condition characterized by a systemic inflammatory response in the setting of infection. We hypothesized that combining antibiotics plus an immunosuppressant would protect against the morbidity and mortality of polymicrobial sepsis in mice better than would antibiotics alone. We used a murine cecal-ligation-and-puncture model in which mice were treated either with imipenem plus cyclophosphamide or imipenem alone. Titration to a low cyclophosphamide dose revealed that combination therapy increased survival by 20% compared with imipenem alone (56% vs. 36%, P < 0.001). To investigate the mechanism by which combination therapy did this, we reviewed quantitative and qualitative markers of the systemic immune response, end-organ damage, and the local immune response at the site of injury. Cyclophosphamide treatment was not associated with depletion of peripheral leukocytes or differences in pulmonary damage. However, mice that received combination therapy had higher plasma granulocyte colony-stimulating factor levels than did those treated with antibiotics alone. In addition, mice treated with cyclophosphamide had higher levels of bacterial colonization in intestinal Peyer's patch lymph nodes at 72 h after the septic insult. Intraperitoneal macrophage phenotypes and phagocytosis activity did not differ between groups. We conclude that the inflammatory response plays a significant role in the mortality of polymicrobial sepsis and that the regulation of this element is both feasible and beneficial in this disease model.
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Mear JB, Gosset P, Kipnis E, Faure E, Dessein R, Jawhara S, Fradin C, Faure K, Poulain D, Sendid B, Guery B. Candida albicans airway exposure primes the lung innate immune response against Pseudomonas aeruginosa infection through innate lymphoid cell recruitment and interleukin-22-associated mucosal response. Infect Immun 2014; 82:306-15. [PMID: 24166952 PMCID: PMC3911865 DOI: 10.1128/iai.01085-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/21/2013] [Indexed: 01/21/2023] Open
Abstract
Pseudomonas aeruginosa and Candida albicans are two pathogens frequently encountered in the intensive care unit microbial community. We have demonstrated that C. albicans airway exposure protected against P. aeruginosa-induced lung injury. The goal of the present study was to characterize the cellular and molecular mechanisms associated with C. albicans-induced protection. Airway exposure by C. albicans led to the recruitment and activation of natural killer cells, innate lymphoid cells (ILCs), macrophages, and dendritic cells. This recruitment was associated with the secretion of interleukin-22 (IL-22), whose neutralization abolished C. albicans-induced protection. We identified, by flow cytometry, ILCs as the only cellular source of IL-22. Depletion of ILCs by anti-CD90.2 antibodies was associated with a decreased IL-22 secretion and impaired survival after P. aeruginosa challenge. Our results demonstrate that the production of IL-22, mainly by ILCs, is a major and inducible step in protection against P. aeruginosa-induced lung injury. This cytokine may represent a clinical target in Pseudomonas aeruginosa-induced lung injury.
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Affiliation(s)
- Jean Baptiste Mear
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Philippe Gosset
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Lille, France
- Université Lille Nord de France, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Institut National de la Santé et de la Recherche Médicale, Lille, France
- Institut Fédératif de Recherche, Lille, France
| | - Eric Kipnis
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Emmanuel Faure
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Rodrigue Dessein
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Samir Jawhara
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Chantal Fradin
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Karine Faure
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
| | - Daniel Poulain
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Boualem Sendid
- INSERM U995, Regulation of Candida Cell Wall Glycan-Host Interface, Faculté de Médecine de Lille, Université Lille Nord de France, CHRU de Lille, Lille, France
| | - Benoit Guery
- Host-Pathogen Translational Research Group, Faculté de Médecine de Lille UDSL–Université Lille Nord de France, Lille, France
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Requirement of the Pseudomonas aeruginosa CbrA sensor kinase for full virulence in a murine acute lung infection model. Infect Immun 2013; 82:1256-67. [PMID: 24379284 DOI: 10.1128/iai.01527-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is a major cause of respiratory tract and other nosocomial infections. The sensor kinase CbrA is a central regulator of carbon and nitrogen metabolism and in vitro also regulates virulence-related processes in P. aeruginosa. Here, we investigated the role of CbrA in two murine models of infection. In both peritoneal infections in leukopenic mice and lung infection models, the cbrA mutant was less virulent since substantially larger numbers of cbrA mutant bacteria were required to cause the same level of infection as wild-type or complemented bacteria. In contrast, in the chronic rat lung model the cbrA mutant grew and persisted as well as the wild type, indicating that the decrease of in vivo virulence of the cbrA mutant did not result from growth deficiencies on particular carbon substrates observed in vitro. In addition, a mutant in the cognate response regulator CbrB showed no defect in virulence in the peritoneal infection model, ruling out the involvement of certain alterations of virulence properties in the cbrA mutant including defective swarming motility, increased biofilm formation, and cytotoxicity, since these alterations are controlled through CbrB. Further investigations indicated that the mutant was more susceptible to uptake by phagocytes in vitro, resulting in greater overall bacterial killing. Consistent with the virulence defect, it took a smaller number of Dictyostelium discoideum amoebae to kill the cbrA mutant than to kill the wild type. Transcriptional analysis of the cbrA mutant during D. discoideum infection led to the conclusion that CbrA played an important role in the iron metabolism, protection of P. aeruginosa against oxidative stress, and the regulation of certain virulence factors.
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Timmermans K, van der Wal SE, Vaneker M, van der Laak JA, Netea MG, Pickkers P, Scheffer GJ, Joosten LA, Kox M. IL-1β processing in mechanical ventilation-induced inflammation is dependent on neutrophil factors rather than caspase-1. Intensive Care Med Exp 2013; 1:27. [PMID: 26266796 PMCID: PMC4797957 DOI: 10.1186/2197-425x-1-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Mechanical ventilation can cause ventilator-induced lung injury, characterized by a sterile inflammatory response in the lungs resulting in tissue damage and respiratory failure. The cytokine interleukin-1β (IL-1β) is thought to play an important role in the pathogenesis of ventilator-induced lung injury. Cleavage of the inactive precursor pro-IL-1β to form bioactive IL-1β is mediated by several types of proteases, of which caspase-1, activated within the inflammasome, is the most important. Herein, we studied the roles of IL-1β, caspase-1 and neutrophil factors in the mechanical ventilation-induced inflammatory response in mice. METHODS Untreated wild-type mice, IL-1αβ knockout and caspase-1 knockout mice, pralnacasan (a selective caspase-1 inhibitor)-treated mice, anti-keratinocyte-derived chemokine (KC)-treated mice and cyclophosphamide-treated neutrophil-depleted wild-type mice were ventilated using clinically relevant ventilator settings (tidal volume 8 ml/kg). The lungs and plasma were collected to determine blood gas values, cytokine profiles and neutrophil influx. RESULTS Mechanical ventilation resulted in increased pulmonary concentrations of IL-1β and KC and increased pulmonary neutrophil influx compared with non-ventilated mice. Ventilated IL-1αβ knockout mice did not demonstrate this increase in cytokines. No significant differences were observed between wild-type and caspase-1-deficient or pralnacasan-treated mice. In contrast, in anti-KC antibody-treated mice and neutropenic mice, inflammatory parameters decreased in comparison with ventilated non-treated mice. CONCLUSIONS Our results illustrate that IL-1 is indeed an important cytokine in the inflammatory cascade induced by mechanical ventilation. However, the inflammasome/caspase-1 appears not to be involved in IL-1β processing in this type of inflammatory response. The attenuated inflammatory response observed in ventilated anti-KC-treated and neutropenic mice suggests that IL-1β processing in mechanical ventilation-induced inflammation is mainly mediated by neutrophil factors.
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Affiliation(s)
- Kim Timmermans
- Department of Anaesthesiology, RUNMC, Nijmegen, 6500 HB, The Netherlands,
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Parra M, Liu X, Derrick SC, Yang A, Tian J, Kolibab K, Kumar S, Morris SL. Molecular analysis of non-specific protection against murine malaria induced by BCG vaccination. PLoS One 2013; 8:e66115. [PMID: 23861742 PMCID: PMC3701530 DOI: 10.1371/journal.pone.0066115] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 05/01/2013] [Indexed: 12/14/2022] Open
Abstract
Although the effectiveness of BCG vaccination in preventing adult pulmonary tuberculosis (TB) has been highly variable, epidemiologic studies have suggested that BCG provides other general health benefits to vaccinees including reducing the impact of asthma, leprosy, and possibly malaria. To further evaluate whether BCG immunization protects against malarial parasitemia and to define molecular correlates of this non-specific immunity, mice were vaccinated with BCG and then challenged 2 months later with asexual blood stage Plasmodium yoelii 17XNL (PyNL) parasites. Following challenge with PyNL, significant decreases in parasitemia were observed in BCG vaccinated mice relative to naïve controls. To identify immune molecules that may be associated with the BCG-induced protection, gene expression was evaluated by RT-PCR in i) naïve controls, ii) BCG-vaccinated mice, iii) PyNL infected mice and iv) BCG vaccinated/PyNL infected mice at 0, 1, 5, and 9 days after the P. yoelii infection. The expression results showed that i) BCG immunization induces the expression of at least 18 genes including the anti-microbial molecules lactoferrin, eosinophil peroxidase, eosinophil major basic protein and the cathelicidin-related antimicrobial peptide (CRAMP); ii) an active PyNL infection suppresses the expression of important immune response molecules; and iii) the extent of PyNL-induced suppression of specific genes is reduced in BCG-vaccinated/PyNL infected mice. To validate the gene expression data, we demonstrated that pre-treatment of malaria parasites with lactoferrin or the cathelicidin LL-37 peptide decreases the level of PyNL parasitemias in mice. Overall, our study suggests that BCG vaccination induces the expression of non-specific immune molecules including antimicrobial peptides which may provide an overall benefit to vaccinees by limiting infections of unrelated pathogens such as Plasmodium parasites.
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Affiliation(s)
- Marcela Parra
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Xia Liu
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Steven C. Derrick
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Amy Yang
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Jinhua Tian
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Kristopher Kolibab
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Sanjai Kumar
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
| | - Sheldon L. Morris
- Center for Biologics Evaluation and Review, USFDA, Bethesda, Maryland, United States of America
- * E-mail:
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Schaal JB, Tran D, Tran P, Ösapay G, Trinh K, Roberts KD, Brasky KM, Tongaonkar P, Ouellette AJ, Selsted ME. Rhesus macaque theta defensins suppress inflammatory cytokines and enhance survival in mouse models of bacteremic sepsis. PLoS One 2012; 7:e51337. [PMID: 23236475 PMCID: PMC3516535 DOI: 10.1371/journal.pone.0051337] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 11/07/2012] [Indexed: 02/08/2023] Open
Abstract
Theta-defensins (θ-defensins) are macrocyclic antimicrobial peptides expressed in leukocytes of Old World monkeys. The peptides are broad spectrum microbicides in vitro and numerous θ-defensin isoforms have been identified in granulocytes of rhesus macaques and Olive baboons. Several mammalian α- and β-defensins, genetically related to θ-defensins, have proinflammatory and immune-activating properties that bridge innate and acquired immunity. In the current study we analyzed the immunoregulatory properties of rhesus θ-defensins 1–5 (RTDs 1–5). RTD-1, the most abundant θ-defensin in macaques, reduced the levels of TNF, IL-1α, IL-1β, IL-6, and IL-8 secreted by blood leukocytes stimulated by several TLR agonists. RTDs 1–5 suppressed levels of soluble TNF released by bacteria- or LPS-stimulated blood leukocytes and THP-1 monocytes. Despite their highly conserved conformation and amino acid sequences, the anti-TNF activities of RTDs 1–5 varied by as much as 10-fold. Systemically administered RTD-1 was non-toxic for BALB/c mice, and escalating intravenous doses were well tolerated and non-immunogenic in adult chimpanzees. The peptide was highly stable in serum and plasma. Single dose administration of RTD-1 at 5 mg/kg significantly improved survival of BALB/c mice with E. coli peritonitis and cecal ligation-and-puncture induced polymicrobial sepsis. Peptide treatment reduced serum levels of several inflammatory cytokines/chemokines in bacteremic animals. Collectively, these results indicate that the anti-inflammatory properties of θ-defensins in vitro and in vivo are mediated by the suppression of numerous proinflammatory cytokines and blockade of TNF release may be a primary effect.
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Affiliation(s)
- Justin B. Schaal
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Dat Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Patti Tran
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - George Ösapay
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, United States of America
| | - Katie Trinh
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kevin D. Roberts
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kathleen M. Brasky
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Prasad Tongaonkar
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - André J. Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Michael E. Selsted
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Kenneth Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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An investigation on the antibacterial, cytotoxic, and antibiofilm efficacy of starch-stabilized silver nanoparticles. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 8:916-24. [DOI: 10.1016/j.nano.2011.11.007] [Citation(s) in RCA: 250] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 10/28/2011] [Accepted: 11/08/2011] [Indexed: 11/22/2022]
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Leow L, Simpson T, Cursons R, Karalus N, Hancox RJ. Vitamin D, innate immunity and outcomes in community acquired pneumonia. Respirology 2011; 16:611-6. [PMID: 21244571 DOI: 10.1111/j.1440-1843.2011.01924.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Vitamin D regulates the production of the antimicrobial peptides cathelicidin and beta-defensin-2, which play an important role in the innate immune response to infection. We hypothesized that vitamin D deficiency would be associated with lower levels of these peptides and worse outcomes in patients admitted to hospital with community acquired pneumonia. METHODS Associations between mortality and serum levels of 25-hydroxyvitamin D, cathelicidin and beta-defensin-2 were investigated in a prospective cohort of 112 patients admitted with community acquired pneumonia during winter. RESULTS Severe 25-hydroxyvitamin D deficiency (<30nmol/L) was common in this population (15%) and was associated with a higher 30-day mortality compared with patients with sufficient 25-hydroxyvitamin D (>50nmol/L) (odds ratio 12.7, 95% confidence interval: 2.2-73.3, P=0.004). These associations were not explained by differences in age, comorbidities, or the severity of the acute illness. Neither cathelicidin nor beta-defensin-2 levels predicted mortality, although there was a trend towards increased mortality with lower cathelicidin (P=0.053). Neither cathelicidin nor beta-defensin-2 levels correlated with 25-hydroxyvitamin D. CONCLUSIONS 25-hydroxyvitamin D deficiency is associated with increased mortality in patients admitted to hospital with community acquired pneumonia during winter. Contrary to our hypothesis, 25-hydroxyvitamin D levels were not associated with levels of cathelicidin or beta-defensin-2.
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Affiliation(s)
- Leong Leow
- Respiratory Research Unit, Waikato Hospital Department of Molecular Genetics, University of Waikato, Hamilton Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand
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Krasnodembskaya A, Song Y, Fang X, Gupta N, Serikov V, Lee JW, Matthay MA. Antibacterial effect of human mesenchymal stem cells is mediated in part from secretion of the antimicrobial peptide LL-37. Stem Cells 2011; 28:2229-38. [PMID: 20945332 DOI: 10.1002/stem.544] [Citation(s) in RCA: 558] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent in vivo studies indicate that mesenchymal stem cells (MSCs) may have beneficial effects in the treatment of sepsis induced by bacterial infection. Administration of MSCs in these studies improved survival and enhanced bacterial clearance. The primary objective of this study was to test the hypothesis that human MSCs possessed intrinsic antimicrobial properties. We studied the effect of human MSCs derived from bone marrow on the bacterial growth of Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. MSCs as well as their conditioned medium (CM) demonstrated marked inhibition of bacterial growth in comparison with control medium or normal human lung fibroblasts (NHLF). Analysis of expression of major antimicrobial peptides indicated that one of the factors responsible for the antimicrobial activity of MSC CM against Gram-negative bacteria was the human cathelicidin antimicrobial peptide, hCAP-18/LL-37. Both m-RNA and protein expression data showed that the expression of LL-37 in MSCs increased after bacterial challenge. Using an in vivo mouse model of E. coli pneumonia, intratracheal administration of MSCs reduced bacterial growth (in colony-forming unit) in the lung homogenates and in the bronchoalveolar lavage (BAL) fluid, and administration of MSCs simultaneously with a neutralizing antibody to LL-37 resulted in a decrease in bacterial clearance. In addition, the BAL itself from MSC-treated mice had a greater antimicrobial activity in comparison with the BAL of phosphate buffered saline (PBS)-treated mice. Human bone marrow-derived MSCs possess direct antimicrobial activity, which is mediated in part by the secretion of human cathelicidin hCAP-18/ LL-37.
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Affiliation(s)
- Anna Krasnodembskaya
- The Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143, USA
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Cathelicidin LL-37: a multitask antimicrobial peptide. Arch Immunol Ther Exp (Warsz) 2010; 58:15-25. [PMID: 20049649 DOI: 10.1007/s00005-009-0057-2] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 04/30/2009] [Indexed: 01/07/2023]
Abstract
The antimicrobial peptide LL-37 is the only known member of the cathelicidin family of peptides expressed in humans. LL-37 is a multifunctional host defense molecule essential for normal immune responses to infection and tissue injury. LL-37 peptide is a potent killer of different microorganisms with the ability to prevent immunostimulatory effects of bacterial wall molecules such as lipopolysaccharide and can therefore protect against lethal endotoxemia. Additional reported activities of LL-37 include chemoattractant function, inhibition of neutrophil apoptosis, and stimulation of angiogenesis, tissue regeneration, and cytokine release (e.g. IL-8). Cellular production of LL-37 is affected by multiple factors, including bacterial products, host cytokines, availability of oxygen, and sun exposure through the activation of CAP-18 gene expression by vitamin D(3). At infection sites, the function of LL-37 can be inhibited by charge-driven interactions with DNA and F-actin released from dead neutrophils and other cells lysed as the result of inflammation. A better understanding of LL-37's biological properties is necessary for its possible therapeutic application for immunomodulatory purposes as well as in treating bacterial infection.
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Killing of trypanosomatid parasites by a modified bovine host defense peptide, BMAP-18. PLoS Negl Trop Dis 2009; 3:e373. [PMID: 19190729 PMCID: PMC2628741 DOI: 10.1371/journal.pntd.0000373] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 01/06/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Tropical diseases caused by parasites continue to cause socioeconomic devastation that reverberates worldwide. There is a growing need for new control measures for many of these diseases due to increasing drug resistance exhibited by the parasites and problems with drug toxicity. One new approach is to apply host defense peptides (HDP; formerly called antimicrobial peptides) to disease control, either to treat infected hosts, or to prevent disease transmission by interfering with parasites in their insect vectors. A potent anti-parasite effector is bovine myeloid antimicrobial peptide-27 (BMAP-27), a member of the cathelicidin family. Although BMAP-27 is a potent inhibitor of microbial growth, at higher concentrations it also exhibits cytotoxicity to mammalian cells. We tested the anti-parasite activity of BMAP-18, a truncated peptide that lacks the hydrophobic C-terminal sequence of the BMAP-27 parent molecule, an alteration that confers reduced toxicity to mammalian cells. METHODOLOGY/PRINCIPAL FINDINGS BMAP-18 showed strong growth inhibitory activity against several species and life cycle stages of African trypanosomes, fish trypanosomes and Leishmania parasites in vitro. When compared to native BMAP-27, the truncated BMAP-18 peptide showed reduced cytotoxicity on a wide variety of mammalian and insect cells and on Sodalis glossindius, a bacterial symbiont of the tsetse vector. The fluorescent stain rhodamine 123 was used in immunofluorescence microscopy and flow cytometry experiments to show that BMAP-18 at low concentrations rapidly disrupted mitochondrial potential without obvious alteration of parasite plasma membranes, thus inducing death by apoptosis. Scanning electron microscopy revealed that higher concentrations of BMAP-18 induced membrane lesions in the parasites as early as 15 minutes after exposure, thus killing them by necrosis. In addition to direct killing of parasites, BMAP-18 was shown to inhibit LPS-induced secretion of tumour necrosis factor alpha (TNF-alpha), a cytokine that is associated with inflammation and cachexia (wasting) in sleeping sickness patients. As a prelude to in vivo applications, high affinity antibodies to BMAP-18 were produced in rabbits and used in immuno-mass spectrometry assays to detect the intact peptide in human blood and plasma. CONCLUSIONS/SIGNIFICANCE BMAP-18, a truncated form of the potent antimicrobial BMAP-27, showed low toxicity to mammalian cells, insect cells and the tsetse bacterial symbiont Sodalis glossinidius while retaining an ability to kill a variety of species and life cycle stages of pathogenic kinetoplastid parasites in vitro. BMAP-18 also inhibited secretion of TNF-alpha, an inflammatory cytokine that plays a role in the cachexia associated with African sleeping sickness. These findings support the idea that BMAP-18 should be explored as a candidate for therapy of economically important trypanosome-infected hosts, such as cattle, fish and humans, and for paratransgenic expression in Sodalis glossinidius, a bacterial symbiont in the tsetse vector, as a strategy for interference with trypanosome transmission.
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WHAT'S NEW IN SHOCK, OCTOBER 2008? Shock 2008; 30:341-3. [DOI: 10.1097/shk.0b013e31818522f5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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