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Linden DA, Guo-Parke H, McKelvey MC, Einarsson GG, Lee AJ, Fairley DJ, Brown V, Lundy G, Campbell C, Logan D, McFarland M, Singh D, McAuley DF, Taggart CC, Kidney JC. Valaciclovir for Epstein-Barr Virus Suppression in Moderate-to-Severe COPD: A Randomized Double-Blind Placebo-Controlled Trial. Chest 2023; 164:625-636. [PMID: 37011709 PMCID: PMC10808072 DOI: 10.1016/j.chest.2023.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/25/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND Epstein-Barr virus (EBV) frequently is measured at high levels in COPD using sputum quantitative polymerase chain reaction, whereas airway immunohistochemistry analysis has shown EBV detection to be common in severe disease. RESEARCH QUESTION Is valaciclovir safe and effective for EBV suppression in COPD? STUDY DESIGN AND METHODS The Epstein-Barr Virus Suppression in COPD (EViSCO) trial was a randomized double-blind placebo-controlled trial conducted at the Mater Hospital Belfast, Northern Ireland. Eligible patients had stable moderate-to-severe COPD and sputum EBV (measured using quantitative polymerase chain reaction) and were assigned randomly (1:1) to valaciclovir (1 g tid) or matching placebo for 8 weeks. The primary efficacy outcome was sputum EBV suppression (defined as ≥ 90% sputum viral load reduction) at week 8. The primary safety outcome was the incidence of serious adverse reactions. Secondary outcome measures were FEV1 and drug tolerability. Exploratory outcomes included changes in quality of life, sputum cell counts, and cytokines. RESULTS From November 2, 2018, through March 12, 2020, 84 patients were assigned randomly (n = 43 to valaciclovir). Eighty-one patients completed trial follow-up and were included in the intention-to-treat analysis of the primary outcome. A greater number of participants in the valaciclovir group achieved EBV suppression (n = 36 [87.8%] vs n = 17 [42.5%]; P < .001). Valaciclovir was associated with a significant reduction in sputum EBV titer compared with placebo (-90,404 copies/mL [interquartile range, -298,000 to -15,200 copies/mL] vs -3,940 copies/mL [interquartile range, -114,400 to 50,150 copies/mL]; P = .002). A statistically nonsignificant 24-mL numerical FEV1 increase was shown in the valaciclovir group (difference, -44 mL [95% CI, -150 to 62 mL]; P = .41). However, a reduction in sputum white cell count was noted in the valaciclovir group compared with the placebo group (difference, 2.89 [95% CI, 1.5 × 106-7.4 × 106]; P = .003). INTERPRETATION Valaciclovir is safe and effective for EBV suppression in COPD and may attenuate the sputum inflammatory cell infiltrate. The findings from the current study provide support for a larger trial to evaluate long-term clinical outcomes. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT03699904; URL: www. CLINICALTRIALS gov.
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Affiliation(s)
- Dermot A Linden
- Mater Hospital Belfast, Belfast Health and Social Care Trus, Belfast, Northern Ireland; Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland.
| | - Hong Guo-Parke
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland
| | - Michael C McKelvey
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland
| | - Gisli G Einarsson
- Halo Research Group, School of Pharmacy, Queen's University Belfast, Belfast, Northern Ireland
| | - Andrew J Lee
- Halo Research Group, School of Pharmacy, Queen's University Belfast, Belfast, Northern Ireland
| | - Derek J Fairley
- Regional Virus Laboratory, Belfast Health and Social Care Trust, Belfast, Northern Ireland
| | - Vanessa Brown
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland
| | - Gavin Lundy
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland
| | | | - Danielle Logan
- Northern Ireland Clinical Trials Unit, Belfast, Northern Ireland
| | | | - Dave Singh
- Division of Infection and Immunity, University of Manchester, Manchester, England
| | - Daniel F McAuley
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland; Royal Victoria Hospital, Belfast, Northern Ireland
| | - Clifford C Taggart
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Belfast, Northern Ireland
| | - Joseph C Kidney
- Mater Hospital Belfast, Belfast Health and Social Care Trus, Belfast, Northern Ireland
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2
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Kalyakulina A, Yusipov I, Kondakova E, Bacalini MG, Franceschi C, Vedunova M, Ivanchenko M. Small immunological clocks identified by deep learning and gradient boosting. Front Immunol 2023; 14:1177611. [PMID: 37691946 PMCID: PMC10485620 DOI: 10.3389/fimmu.2023.1177611] [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: 03/01/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
Background The aging process affects all systems of the human body, and the observed increase in inflammatory components affecting the immune system in old age can lead to the development of age-associated diseases and systemic inflammation. Results We propose a small clock model SImAge based on a limited number of immunological biomarkers. To regress the chronological age from cytokine data, we first use a baseline Elastic Net model, gradient-boosted decision trees models, and several deep neural network architectures. For the full dataset of 46 immunological parameters, DANet, SAINT, FT-Transformer and TabNet models showed the best results for the test dataset. Dimensionality reduction of these models with SHAP values revealed the 10 most age-associated immunological parameters, taken to construct the SImAge small immunological clock. The best result of the SImAge model shown by the FT-Transformer deep neural network model has mean absolute error of 6.94 years and Pearson ρ = 0.939 on the independent test dataset. Explainable artificial intelligence methods allow for explaining the model solution for each individual participant. Conclusions We developed an approach to construct a model of immunological age based on just 10 immunological parameters, coined SImAge, for which the FT-Transformer deep neural network model had proved to be the best choice. The model shows competitive results compared to the published studies on immunological profiles, and takes a smaller number of features as an input. Neural network architectures outperformed gradient-boosted decision trees, and can be recommended in the further analysis of immunological profiles.
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Affiliation(s)
- Alena Kalyakulina
- Research Center for Trusted Artificial Intelligence, Ivannikov Institute for System Programming of the Russian Academy of Sciences, Moscow, Russia
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University, Nizhny Novgorod, Russia
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
| | - Igor Yusipov
- Research Center for Trusted Artificial Intelligence, Ivannikov Institute for System Programming of the Russian Academy of Sciences, Moscow, Russia
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University, Nizhny Novgorod, Russia
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
| | - Elena Kondakova
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
- Institute of Neuroscience, Lobachevsky State University, Nizhny Novgorod, Russia
| | | | - Claudio Franceschi
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University, Nizhny Novgorod, Russia
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
| | - Maria Vedunova
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
| | - Mikhail Ivanchenko
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky State University, Nizhny Novgorod, Russia
- Institute of Biogerontology, Lobachevsky State University, Nizhny Novgorod, Russia
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3
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Doroftei B, Ilie OD, Maftei R, Scripcariu IS, Armeanu T, Stoian IL, Ilea C. A Narrative Review Discussing Vasectomy-Related Impact upon the Status of Oxidative Stress and Inflammation Biomarkers and Semen Microbiota. J Clin Med 2023; 12:jcm12072671. [PMID: 37048754 PMCID: PMC10095584 DOI: 10.3390/jcm12072671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 04/07/2023] Open
Abstract
Background: Male contraceptive approaches besides tubal sterilization involve vasectomy and represent the method of choice among midlife men in developing countries thanks to many advantages. However, the subsidiary consequences of this intervention are insufficiently explored since the involved mechanisms may offer insight into a much more complex picture. Methods: Thus, in this manuscript, we aimed to reunite all available data by searching three separate academic database(s) (PubMed, Web of Knowledge, and Scopus) published in the past two decades by covering the interval 2000–2023 and using a predefined set of keywords and strings involving “oxidative stress” (OS), “inflammation”, and “semen microbiota” in combination with “humans”, “rats”, and “mice”. Results: By following all evidence that fits in the pre-, post-, and vasectomy reversal (VR) stages, we identified a total of n = 210 studies from which only n = 21 were finally included following two procedures of eligibility evaluation. Conclusions: The topic surrounding this intricate landscape has created debate since the current evidence is contradictory, limited, or does not exist. Starting from this consideration, we argue that further research is mandatory to decipher how a vasectomy might disturb homeostasis.
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Affiliation(s)
- Bogdan Doroftei
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
- Clinical Hospital of Obstetrics and Gynecology “Cuza Voda”, Cuza Voda Street no 34, 700038 Iasi, Romania
- Origyn Fertility Center, Palace Street, no 3C, 700032 Iasi, Romania
| | - Ovidiu-Dumitru Ilie
- Department of Biology, Faculty of Biology, “Alexandru Ioan Cuza” University, Carol I Avenue no 20A, 700505 Iasi, Romania
| | - Radu Maftei
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
- Clinical Hospital of Obstetrics and Gynecology “Cuza Voda”, Cuza Voda Street no 34, 700038 Iasi, Romania
- Origyn Fertility Center, Palace Street, no 3C, 700032 Iasi, Romania
| | - Ioana-Sadyie Scripcariu
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
- Clinical Hospital of Obstetrics and Gynecology “Cuza Voda”, Cuza Voda Street no 34, 700038 Iasi, Romania
| | - Theodora Armeanu
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
- Clinical Hospital of Obstetrics and Gynecology “Cuza Voda”, Cuza Voda Street no 34, 700038 Iasi, Romania
- Origyn Fertility Center, Palace Street, no 3C, 700032 Iasi, Romania
| | - Irina-Liviana Stoian
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
| | - Ciprian Ilea
- Faculty of Medicine, University of Medicine and Pharmacy “Grigore T. Popa”, University Street no 16, 700115 Iasi, Romania
- Clinical Hospital of Obstetrics and Gynecology “Cuza Voda”, Cuza Voda Street no 34, 700038 Iasi, Romania
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Duarte-Mata DI, Salinas-Carmona MC. Antimicrobial peptides´ immune modulation role in intracellular bacterial infection. Front Immunol 2023; 14:1119574. [PMID: 37056758 PMCID: PMC10086130 DOI: 10.3389/fimmu.2023.1119574] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Intracellular bacteria cause a wide range of diseases, and their intracellular lifestyle makes infections difficult to resolve. Furthermore, standard therapy antibiotics are often unable to eliminate the infection because they have poor cellular uptake and do not reach the concentrations needed to kill bacteria. In this context, antimicrobial peptides (AMPs) are a promising therapeutic approach. AMPs are short cationic peptides. They are essential components of the innate immune response and important candidates for therapy due to their bactericidal properties and ability to modulate host immune responses. AMPs control infections through their diverse immunomodulatory effects stimulating and/or boosting immune responses. This review focuses on AMPs described to treat intracellular bacterial infections and the known immune mechanisms they influence.
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Disparate Regions of the Human Chemokine CXCL10 Exhibit Broad-Spectrum Antimicrobial Activity against Biodefense and Antibiotic-Resistant Bacterial Pathogens. ACS Infect Dis 2022; 9:122-139. [PMID: 36475632 PMCID: PMC9841529 DOI: 10.1021/acsinfecdis.2c00456] [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] [Indexed: 12/12/2022]
Abstract
CXCL10 is a pro-inflammatory chemokine produced by the host in response to microbial infection. In addition to canonical, receptor-dependent actions affecting immune-cell migration and activation, CXCL10 has also been found to directly kill a broad range of pathogenic bacteria. Prior investigations suggest that the bactericidal effects of CXCL10 occur through two distinct pathways that compromise the cell envelope. These observations raise the intriguing notion that CXCL10 features a separable pair of antimicrobial domains. Herein, we affirm this possibility through peptide-based mapping and structure/function analyses, which demonstrate that discrete peptides derived from the N- and C-terminal regions of CXCL10 mediate bacterial killing. The N-terminal derivative, peptide P1, exhibited marked antimicrobial activity against Bacillus anthracis vegetative bacilli and spores, as well as antibiotic-resistant clinical isolates of Klebsiella pneumoniae, Acinetobacter baumannii, Enterococcus faecium, and Staphylococcus aureus, among others. At bactericidal concentrations, peptide P1 had a minimal degree of chemotactic activity, but did not cause red blood cell hemolysis or cytotoxic effects against primary human cells. The C-terminal derivative, peptide P9, exhibited antimicrobial effects, but only against Gram-negative bacteria in low-salt medium─conditions under which the peptide can adopt an α-helical conformation. The introduction of a hydrocarbon staple induced and stabilized α-helicity; accordingly, stapled peptide P9 displayed significantly improved bactericidal effects against both Gram-positive and Gram-negative bacteria in media containing physiologic levels of salt. Together, our findings identify and characterize the antimicrobial regions of CXCL10 and functionalize these novel determinants as discrete peptides with potential therapeutic utility against difficult-to-treat pathogens.
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Barta I, Paska C, Antus B. Sputum Cytokine Profiling in COPD: Comparison Between Stable Disease and Exacerbation. Int J Chron Obstruct Pulmon Dis 2022; 17:1897-1908. [PMID: 36017119 PMCID: PMC9397440 DOI: 10.2147/copd.s364982] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/21/2022] [Indexed: 12/03/2022] Open
Abstract
Purpose Cytokines are extracellular signaling proteins that have been widely implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Here, we investigated cytokine expression both at the mRNA and protein level in the sputum of healthy individuals, stable COPD patients, and those experiencing a severe acute exacerbation (AECOPD) requiring hospitalization. Patients and Methods Sputum was collected in 19 healthy controls, 25 clinically stable COPD patients, and 31 patients with AECOPD. In AECOPD patients sample collection was performed both at the time of hospital admission and at discharge following treatment. Sputum supernatant was analyzed by an antibody microarray detecting 120 cytokines simultaneously, while the mRNA expression of 14 selected cytokines in sputum cells was investigated by real-time PCR (qPCR). Results Proteomic analysis identified interleukin (IL)-6 and growth-regulated oncogene (GRO)α as the only sputum cytokines that were differentially expressed between stable COPD patients and healthy controls. At the onset of AECOPD, several cytokines exhibited altered sputum expression compared to stable COPD. Recovery from AECOPD induced significant changes in the sputum cytokine protein profile; however, the length of hospitalization was insufficient for most cytokines to return to stable levels. With regard to gene expression analysis by qPCR, we found that bone morphogenetic protein (BMP)-4 was up-regulated, while IL-1α, monokine-induced by interferon-γ (MIG), and BMP-6 were down-regulated at the mRNA level in patients with AECOPD compared to stable disease. Conclusion The sputum cytokine signature of AECOPD differs from that of stable COPD. Protein level changes are asynchronous with changes in gene expression at the mRNA level in AECOPD. The observation that the levels of most cytokines do not stabilize with acute treatment of AECOPD suggests a prolonged effect of exacerbation on the status of COPD patients.
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Affiliation(s)
- Imre Barta
- Department of Pathophysiology, National Koranyi Institute of Pulmonology, Budapest, Hungary
| | - Csilla Paska
- Department of Pathophysiology, National Koranyi Institute of Pulmonology, Budapest, Hungary
| | - Balazs Antus
- Department of Pathophysiology, National Koranyi Institute of Pulmonology, Budapest, Hungary.,Department of Pulmonology, National Koranyi Institute of Pulmonology, Budapest, Hungary
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7
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Wei J, Zhang C, Gao Y, Li Y, Zhang Q, Qi H, Jin M, Yang X, Su X, Zhang Y, Yang R. Gut Epithelial-derived CXCL9 Maintains Gut Homeostasis Through Preventing Overgrown E. coli. J Crohns Colitis 2022; 16:963-977. [PMID: 34964882 DOI: 10.1093/ecco-jcc/jjab234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/25/2021] [Accepted: 12/25/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS Increased E. coli in the colon are related to the occurrence and development of multiple diseases. Chemokines are shown to possess potential antimicrobial activity, including against Gram-positive and -negative bacterial pathogens. We here investigated function[s] of chemokine CXCL9 expressed in the gut epithelial cells, and mechanism[s] of CXCL9 by which to kill E. coli. METHODS We generated CXCL9fl/flpvillin-creT mice [pvillin-cre positive mice] and their control CXCL9fl/flpvillin-crewmice [pvillin-cre negative mice], and then employed a dextran sulphate sodium [DSS]-mediated colitis model to determine the sensitivity of CXCL9fl/flpvillin-creT mice. We analysed the composition of the gut microbiota by using 16S ribosomal RNA [V3-V4 variable region] sequencing and shotgun metagenomic analyses. We generated E. coli ΔFtsX [FtsX-depleted E. coli] and E. coli ΔaceE [aceE-depleted E. coli] by using a bacterium red recombining system to investigate the mechanism[s] of CXCL9 by which to kill E. coli. RESULTS CXCL9 fl/flpvillin-creTmice were more sensitive to chemically induced colitis than their control littermates, CXCL9fl/flpvillin-crewmice. After DSS treatment, there were markedly increased gut E. coli [Escherichia-Shigella] in the colonic contents of CXCL9fl/flpvillin-creT mice as compared with control CXCL9fl/flpvillin-crew mice. The increased E. coli could promote colitis through NLRC4 and caspase 1/11-mediated IL-18, which was derived from gut epithelial cells. We finally demonstrated that CXCL9 expressed in gut epithelial cells could kill the overgrown E. coli. E. coli expressed Ftsx and PDHc subunits aceE. E.coliΔaceE but not E. coliΔFtsX were resistant to CXCL9-mediated killing. CONCLUSIONS Gut epithelial cells-derived CXCL9 can kill the expanded E. coli through aceE, to remain gut homeostasis.
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Affiliation(s)
- Jianmei Wei
- Translational Medicine Institute, Tianjin Union Medical Center of Nankai University, Tianjin,China.,Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Chunze Zhang
- Translational Medicine Institute, Tianjin Union Medical Center of Nankai University, Tianjin,China.,Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin,China
| | - Yunhuan Gao
- Translational Medicine Institute, Tianjin Union Medical Center of Nankai University, Tianjin,China.,Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Yuanyuan Li
- Translational Medicine Institute, Tianjin Union Medical Center of Nankai University, Tianjin,China.,Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Qianjing Zhang
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Houbao Qi
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Mengli Jin
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Xiaorong Yang
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Xiaomin Su
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Yuan Zhang
- Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China
| | - Rongcun Yang
- Translational Medicine Institute, Tianjin Union Medical Center of Nankai University, Tianjin,China.,Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China.,State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.,Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, China
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8
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LcCCL28-25, Derived from Piscine Chemokine, Exhibits Antimicrobial Activity against Gram-Negative and Gram-Positive Bacteria In Vitro and In Vivo. Microbiol Spectr 2022; 10:e0251521. [PMID: 35616397 PMCID: PMC9241943 DOI: 10.1128/spectrum.02515-21] [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] [Indexed: 11/24/2022] Open
Abstract
Antimicrobial peptides (AMPs) are currently recognized as potentially promising antibiotic substitutes. Fish are an important seawater/freshwater medicinal biological resource, and the antimicrobial peptides and proteins that are key components of their innate immune systems are potential candidates for the development of novel antibacterial agents. The rainbow trout Oncorhynchus mykiss chemokine CK11 (omCK11), classified in the C-C motif chemokine ligand 27/28 (CCL27/28) family, is the only CC-type chemokine reported to play a direct antibacterial role in the immune response; however, its antibacterial domain remains unknown. In this study, we analyzed the structure-activity relationship of omCK11 and identified the antibacterial C-terminal domain. Additionally, we performed structure-function analyses of CCL27/28 proteins from different, representative freshwater and seawater fishes, revealing their shared C-terminal antibacterial domains. Surprisingly, a synthesized cationic peptide (named lcCCL28-25), derived from the large yellow croaker Larimichthys crocea CCL28, exhibited broad-spectrum and the most acceptable bactericidal activity, as well as antibiofilm activity and negligible hemolytic and cytotoxic activity in vitro. Additionally, lcCCL28-25 conferred a protective effect in the thighs of neutropenic mice infected with Staphylococcus aureus. SYTOX green fluorescence and electron microscopy experiments revealed that lcCCL28-25 was capable of rapidly destroying the integrity and permeability of the bacterial cell membrane. Overall, this study aided in the advancement of antibacterial CC-type chemokine research and also suggested a new strategy for exploring novel AMPs. Additionally, the efficacy of lcCCL28-25 in in vivo antibacterial activity in a mammalian model revealed that this compound could be a promising agent for the development of peptide-based antibacterial therapeutics. IMPORTANCE The primary function of chemokines has been described as recruiting and activating leukocytes to participate in the immune response. Some chemokines are also broad-spectrum antibacterial proteins in mammals. The Oncorhynchus mykiss chemokine CK11 (omCK11) is the first reported and currently the only CC-type antibacterial chemokine. The present study identified the antibacterial domain of omCK11. Structure-function analysis of various fish CCL27/28 proteins identified a novel antibacterial peptide (lcCCL28-25) from Larimichthys crocea CCL28 that exhibited broad-spectrum and the most acceptable bactericidal activity in vitro, as well as a protective effect in a Staphylococcus aureus infection mouse model. The antibacterial mechanisms included membrane disruption and permeation. This study advanced the field of antibacterial chemokine research in fish and also suggested a new strategy for exploring novel AMPs. The novel peptide lcCCL28-25 may prove to be an effective antibacterial agent.
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Anderson J, Imran S, Frost HR, Azzopardi KI, Jalali S, Novakovic B, Osowicki J, Steer AC, Licciardi PV, Pellicci DG. Immune signature of acute pharyngitis in a Streptococcus pyogenes human challenge trial. Nat Commun 2022; 13:769. [PMID: 35140232 PMCID: PMC8828729 DOI: 10.1038/s41467-022-28335-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 01/18/2022] [Indexed: 01/27/2023] Open
Abstract
Streptococcus pyogenes causes at least 750 million infections and more than 500,000 deaths each year. No vaccine is currently available for S. pyogenes and the use of human challenge models offer unique and exciting opportunities to interrogate the immune response to infectious diseases. Here, we use high-dimensional flow cytometric analysis and multiplex cytokine and chemokine assays to study serial blood and saliva samples collected during the early immune response in human participants following challenge with S. pyogenes. We find an immune signature of experimental human pharyngitis characterised by: 1) elevation of serum IL-1Ra, IL-6, IFN-γ, IP-10 and IL-18; 2) increases in peripheral blood innate dendritic cell and monocyte populations; 3) reduced circulation of B cells and CD4+ T cell subsets (Th1, Th17, Treg, TFH) during the acute phase; and 4) activation of unconventional T cell subsets, γδTCR + Vδ2+ T cells and MAIT cells. These findings demonstrate that S. pyogenes infection generates a robust early immune response, which may be important for host protection. Together, these data will help advance research to establish correlates of immune protection and focus the evaluation of vaccines.
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Affiliation(s)
- Jeremy Anderson
- Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Samira Imran
- Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Hannah R Frost
- Murdoch Children's Research Institute, Melbourne, Australia
| | | | - Sedigheh Jalali
- Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Boris Novakovic
- Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Joshua Osowicki
- Murdoch Children's Research Institute, Melbourne, Australia. .,Department of Paediatrics, University of Melbourne, Melbourne, Australia. .,Infectious Diseases Unit, Department of General Medicine, The Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia.
| | - Andrew C Steer
- Murdoch Children's Research Institute, Melbourne, Australia. .,Department of Paediatrics, University of Melbourne, Melbourne, Australia. .,Infectious Diseases Unit, Department of General Medicine, The Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia.
| | - Paul V Licciardi
- Murdoch Children's Research Institute, Melbourne, Australia. .,Department of Paediatrics, University of Melbourne, Melbourne, Australia.
| | - Daniel G Pellicci
- Murdoch Children's Research Institute, Melbourne, Australia. .,Department of Paediatrics, University of Melbourne, Melbourne, Australia. .,Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia.
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10
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Cytokines Induced by Edwardsiella tarda: Profile and Role in Antibacterial Immunity. Biomolecules 2021; 11:biom11081242. [PMID: 34439908 PMCID: PMC8391551 DOI: 10.3390/biom11081242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/05/2021] [Accepted: 08/16/2021] [Indexed: 01/18/2023] Open
Abstract
Edwardsiella tarda is a Gram-negative bacterial pathogen with a broad range of hosts, including fish and mammals. In the present study, we used an advanced antibody array technology to identify the expression pattern of cytokines induced by E. tarda in a mouse infection model. In total, 31 and 24 differentially expressed cytokines (DECs) were identified in the plasma at 6 h and 24 h post-infection (hpi), respectively. The DECs were markedly enriched in the Gene Ontology (GO) terms associated with cell migration and response to chemokine and in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with immunity, diseases, and infection. Ten key DECs, including IL6 and TNF-α, were found to form extensive protein-protein interaction networks. IL6 was demonstrated to inhibit E. tarda infection and be required for E. tarda-induced inflammatory response. TNF-α also exerted an inhibitory effect on E. tarda infection, and knockdown of fish (Japanese flounder) TNF-α promoted E. tarda invasion in host cells. Together, the results of this study revealed a comprehensive profile of cytokines induced by E. tarda, thus adding new insights into the role of cytokine-associated immunity against bacterial infection and also providing the potential plasma biomarkers of E. tarda infection for future studies.
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Neumann A, Happonen L, Karlsson C, Bahnan W, Frick IM, Björck L. Streptococcal protein SIC activates monocytes and induces inflammation. iScience 2021; 24:102339. [PMID: 33855284 PMCID: PMC8027542 DOI: 10.1016/j.isci.2021.102339] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/21/2021] [Accepted: 03/16/2021] [Indexed: 02/08/2023] Open
Abstract
Streptococcus pyogenes is a major bacterial pathogen in the human population and isolates of the clinically important M1 serotype secrete protein Streptococcal inhibitor of complement (SIC) known to interfere with human innate immunity. Here we find that SIC from M1 bacteria interacts with TLR2 and CD14 on monocytes leading to the activation of the NF-κB and p38 MAPK pathways and the release of several pro-inflammatory cytokines (e.g. TNFα and INFγ). In human plasma, SIC binds clusterin and histidine-rich glycoprotein, and whole plasma, and these two purified plasma proteins enhanced the activation of monocytes by SIC. Isolates of the M55 serotype secrete an SIC homolog, but this protein did not activate monocytes. M1 isolates are common in cases of invasive S. pyogenes infections characterized by massive inflammation, and the results of this study indicate that the pro-inflammatory property of SIC contributes to the pathology of these severe clinical conditions.
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Affiliation(s)
- Ariane Neumann
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Wael Bahnan
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Inga-Maria Frick
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences, BMC, Lund University, 22184, Lund, Sweden
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12
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Siwek W, Tehrani SSH, Mata JF, Jansen LET. Activation of Clustered IFNγ Target Genes Drives Cohesin-Controlled Transcriptional Memory. Mol Cell 2020; 80:396-409.e6. [PMID: 33108759 PMCID: PMC7657446 DOI: 10.1016/j.molcel.2020.10.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/31/2020] [Accepted: 10/01/2020] [Indexed: 12/15/2022]
Abstract
Cytokine activation of cells induces gene networks involved in inflammation and immunity. Transient gene activation can have a lasting effect even in the absence of ongoing transcription, known as long-term transcriptional memory. Here we explore the nature of the establishment and maintenance of interferon γ (IFNγ)-induced priming of human cells. We find that, although ongoing transcription and local chromatin signatures are short-lived, the IFNγ-primed state stably propagates through at least 14 cell division cycles. Single-cell analysis reveals that memory is manifested by an increased probability of primed cells to engage in target gene expression, correlating with the strength of initial gene activation. Further, we find that strongly memorized genes tend to reside in genomic clusters and that long-term memory of these genes is locally restricted by cohesin. We define the duration, stochastic nature, and molecular mechanisms of IFNγ-induced transcriptional memory, relevant to understanding enhanced innate immune signaling.
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Affiliation(s)
- Wojciech Siwek
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
| | - Sahar S H Tehrani
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - João F Mata
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Lars E T Jansen
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
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13
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Moussouras NA, Hjortø GM, Peterson FC, Szpakowska M, Chevigné A, Rosenkilde MM, Volkman BF, Dwinell MB. Structural Features of an Extended C-Terminal Tail Modulate the Function of the Chemokine CCL21. Biochemistry 2020; 59:1338-1350. [PMID: 32182428 DOI: 10.1021/acs.biochem.0c00047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The chemokines CCL21 and CCL19, through binding of their cognate receptor CCR7, orchestrate lymph node homing of dendritic cells and naïve T cells. CCL21 differs from CCL19 via an unstructured 32 residue C-terminal domain. Previously described roles for the CCL21 C-terminus include GAG-binding, spatial localization to lymphatic vessels, and autoinhibitory modulation of CCR7-mediated chemotaxis. While truncation of the C-terminal tail induced chemical shift changes in the folded chemokine domain, the structural basis for its influence on CCL21 function remains largely unexplored. CCL21 concentration-dependent NMR chemical shifts revealed weak, nonphysiological self-association that mimics the truncation of the C-terminal tail. We generated a series of C-terminal truncation variants to dissect the C-terminus influence on CCL21 structure and receptor activation. Using NMR spectroscopy, we found that CCL21 residues 80-90 mediate contacts with the chemokine domain. In cell-based assays for CCR7 and ACKR4 activation, we also found that residues 92-100 reduced CCL21 potency in calcium flux, cAMP inhibition, and β-arrestin recruitment. Taken together, these structure-function studies support a model wherein intramolecular interactions with specific residues of the flexible C-terminus stabilize a less active monomer conformation of the CCL21. We speculate that the autoinhibitory intramolecular contacts between the C-terminal tail and chemokine body are disrupted by GAG binding and/or interactions with the CCR7 receptor to ensure optimal functionality.
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Affiliation(s)
- Natasha A Moussouras
- From the Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Gertrud M Hjortø
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Martyna Szpakowska
- Department of Infection and Immunity, Immuno-Pharmacology and Interactomics, Luxembourg Institute of Health, Esch-sur-Alzette L-4354, Luxembourg
| | - Andy Chevigné
- Department of Infection and Immunity, Immuno-Pharmacology and Interactomics, Luxembourg Institute of Health, Esch-sur-Alzette L-4354, Luxembourg
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Michael B Dwinell
- From the Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
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14
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Tangedal S, Nielsen R, Aanerud M, Persson LJ, Wiker HG, Bakke PS, Hiemstra PS, Eagan TM. Sputum microbiota and inflammation at stable state and during exacerbations in a cohort of chronic obstructive pulmonary disease (COPD) patients. PLoS One 2019; 14:e0222449. [PMID: 31527888 PMCID: PMC6748569 DOI: 10.1371/journal.pone.0222449] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 08/30/2019] [Indexed: 11/25/2022] Open
Abstract
Background Exacerbations of chronic obstructive pulmonary disease (COPD) are debilitating events and spur disease progression. Infectious causes are frequent; however, it is unknown to what extent exacerbations are caused by larger shifts in the airways’ microbiota. The aim of the current study was to analyse the changes in microbial composition between stable state and during exacerbations, and the corresponding immune response. Methods The study sample included 36 COPD patients examined at stable state and exacerbation from the Bergen COPD Cohort and Exacerbations studies, and one patient who delivered sputum on 13 different occasions during the three-year study period. A physician examined the patients at all time points, and sputum induction was performed by stringent protocol. Only induced sputum samples were used in the current study, not spontaneously expectorated sputum. Sputum inflammatory markers (IL-6, IL-8, IL-18, IP-10, MIG, TNF-α) and antimicrobial peptides (AMPs, i.e. LL-37/hCAP-18, SLPI) were measured in supernatants, whereas target gene sequencing (16S rRNA) was performed on corresponding cell pellets. The microbiome bioinformatics platform QIIME2TM and the statistics environment R were applied for bioinformatics analyses. Results Levels of IP-10, MIG, TNF-α and AMPs were significantly different between the two disease states. Of 36 sample pairs, 24 had significant differences in the 12 most abundant genera between disease states. The diversity was significantly different in several individuals, but not when data was analysed on a group level. The one patient case study showed longitudinal dynamics in microbiota unrelated to disease state. Conclusion Changes in the sputum microbiota with changing COPD disease states are common, and are accompanied by changes in inflammatory markers. However, the changes are highly individual and heterogeneous events.
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Affiliation(s)
- Solveig Tangedal
- Dept. of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- Dept. of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway
- * E-mail:
| | - Rune Nielsen
- Dept. of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- Dept. of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway
| | - Marianne Aanerud
- Dept. of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway
| | - Louise J. Persson
- Dept. of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway
| | - Harald G. Wiker
- Dept. of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- Dept. of Microbiology, Haukeland University Hospital, Bergen, Norway
| | - Per S. Bakke
- Dept. of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Pieter S. Hiemstra
- Dept of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tomas M. Eagan
- Dept. of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- Dept. of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway
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15
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Phage Therapy of Pneumonia Is Not Associated with an Overstimulation of the Inflammatory Response Compared to Antibiotic Treatment in Mice. Antimicrob Agents Chemother 2019; 63:AAC.00379-19. [PMID: 31182526 DOI: 10.1128/aac.00379-19] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/02/2019] [Indexed: 12/12/2022] Open
Abstract
Supported by years of clinical use in some countries and more recently by literature on experimental models, as well as its compassionate use in Europe and in the United States, bacteriophage (phage) therapy is providing a solution for difficult-to-treat bacterial infections. However, studies of the impact of such treatments on the host remain scarce. Murine acute pneumonia initiated by intranasal instillation of two pathogenic strains of Escherichia coli (536 and LM33) was treated by two specific bacteriophages (536_P1 and LM33_P1; intranasal) or antibiotics (ceftriaxone, cefoxitin, or imipenem-cilastatin; intraperitoneal). Healthy mice also received phages alone. The severity of pulmonary edema, acute inflammatory cytokine concentration (blood and lung homogenates), complete blood counts, and bacterial and bacteriophage counts were determined at early (≤12 h) and late (≥20 h) time points. The efficacy of bacteriophage to decrease bacterial load was faster than with antibiotics, but the two displayed similar endpoints. Bacteriophage treatment was not associated with overinflammation but in contrast tended to lower inflammation and provided a faster correction of blood cell count abnormalities than did antibiotics. In the absence of bacterial infection, bacteriophage 536_P1 promoted a weak increase in the production of antiviral cytokines (gamma interferon [IFN-γ] and interleukin-12 [IL-12]) and chemokines in the lungs but not in the blood. However, such variations were no longer observed when bacteriophage 536_P1 was administered to treat infected animals. The rapid lysis of bacteria by bacteriophages in vivo does not increase the innate inflammatory response compared to that with antibiotic treatment.
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16
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Hazin-Costa MF, da Silva Aráujo A, Guerra GL, da Matta MC, Torres LC, Souza AI. Chemokines in pregnant women with sickle cell disease. Cytokine 2018; 113:195-199. [PMID: 30006250 DOI: 10.1016/j.cyto.2018.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 06/27/2018] [Accepted: 07/02/2018] [Indexed: 12/31/2022]
Abstract
Pregnancy in sickle cell disease is a problem due to the adverse outcomes related to the disease. Research into the role of chemokines in sickle cell disease is available, but studies investigating the disease in pregnancy are scarce. Our data show the chemokine profiles of pregnant women with sickle cell disease compared with control groups. There were no differences in MCP-1 level among the groups, but IL-8 and MIG were likely related with disease activity. In addition, levels of IP-10 were higher in pregnant women with sickle cell disease and, interestingly, RANTES levels were higher in normal pregnancy when compared to pregnancy in sickle cell disease. More studies should be encouraged to fully elucidate chemokine activity during pregnancy in sickle cell disease.
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Affiliation(s)
- Manuela Freire Hazin-Costa
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, Boa Vista, 50.070-550 Recife, Pernambuco, Brazil; Fundação de Hematologia e Hemoterapia de Pernambuco HEMOPE, Rua Joaquim Nabuco, 171, Graças, 52.011-000 Recife, Pernambuco, Brazil; Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, 50.670-90 Recife, Pernambuco, Brazil.
| | - Aderson da Silva Aráujo
- Fundação de Hematologia e Hemoterapia de Pernambuco HEMOPE, Rua Joaquim Nabuco, 171, Graças, 52.011-000 Recife, Pernambuco, Brazil
| | - Glaucia Lins Guerra
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, Boa Vista, 50.070-550 Recife, Pernambuco, Brazil
| | - Marina Cadena da Matta
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, Boa Vista, 50.070-550 Recife, Pernambuco, Brazil
| | - Leuridan Cavalcante Torres
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, Boa Vista, 50.070-550 Recife, Pernambuco, Brazil
| | - Ariani Impieri Souza
- Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, Boa Vista, 50.070-550 Recife, Pernambuco, Brazil; Faculdade Pernambucana de Saúde (FPS), Av. Mal. Mascarenhas de Morais, 4861, Imbiribeira, 51.180-001 Recife, Pernambuco, Brazil
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17
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Frick IM, Shannon O, Neumann A, Karlsson C, Wikström M, Björck L. Streptococcal inhibitor of complement (SIC) modulates fibrinolysis and enhances bacterial survival within fibrin clots. J Biol Chem 2018; 293:13578-13591. [PMID: 30002122 PMCID: PMC6120194 DOI: 10.1074/jbc.ra118.001988] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 07/11/2018] [Indexed: 11/06/2022] Open
Abstract
Some strains of the bacterial pathogen Streptococcus pyogenes secrete protein SIC (streptococcal inhibitor of complement), including strains of the clinically relevant M1 serotype. SIC neutralizes the effect of a number of antimicrobial proteins/peptides and interferes with the function of the host complement system. Previous studies have shown that some S. pyogenes proteins bind and modulate coagulation and fibrinolysis factors, raising the possibility that SIC also may interfere with the activity of these factors. Here we show that SIC interacts with both human thrombin and plasminogen, key components of coagulation and fibrinolysis. We found that during clot formation, SIC binds fibrin through its central region and that SIC inhibits fibrinolysis by interacting with plasminogen. Flow cytometry results indicated that SIC and plasminogen bind simultaneously to S. pyogenes bacteria, and fluorescence microscopy revealed co-localization of the two proteins at the bacterial surface. As a consequence, SIC-expressing bacteria entrapped in clots inhibit fibrinolysis, leading to delayed bacterial escape from the clots as compared with mutant bacteria lacking SIC. Moreover, within the clots SIC-expressing bacteria were protected against killing. In an animal model of subcutaneous infection, SIC-expressing bacteria exhibited a delayed systemic spread. These results demonstrate that the bacterial protein SIC interferes with coagulation and fibrinolysis and thereby enhances bacterial survival, a finding that has significant implications for S. pyogenes virulence.
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Affiliation(s)
- Inga-Maria Frick
- From the Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden and
| | - Oonagh Shannon
- From the Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden and
| | - Ariane Neumann
- From the Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden and
| | - Christofer Karlsson
- From the Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden and
| | - Mats Wikström
- the University of Copenhagen, Protein Function and Interactions Group, Novo Nordisk Foundation Center for Protein Research, DK-2200 Copenhagen, Denmark
| | - Lars Björck
- From the Department of Clinical Sciences, Lund, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden and
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18
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Soderholm AT, Barnett TC, Korn O, Rivera-Hernandez T, Seymour LM, Schulz BL, Nizet V, Wells CA, Sweet MJ, Walker MJ. Group A Streptococcus M1T1 Intracellular Infection of Primary Tonsil Epithelial Cells Dampens Levels of Secreted IL-8 Through the Action of SpyCEP. Front Cell Infect Microbiol 2018; 8:160. [PMID: 29868516 PMCID: PMC5966554 DOI: 10.3389/fcimb.2018.00160] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 04/26/2018] [Indexed: 11/22/2022] Open
Abstract
Streptococcus pyogenes (Group A Streptococcus; GAS) commonly causes pharyngitis in children and adults, with severe invasive disease and immune sequelae being an infrequent consequence. The ability of GAS to invade the host and establish infection likely involves subversion of host immune defenses. However, the signaling pathways and innate immune responses of epithelial cells to GAS are not well-understood. In this study, we utilized RNAseq to characterize the inflammatory responses of primary human tonsil epithelial (TEpi) cells to infection with the laboratory-adapted M6 strain JRS4 and the M1T1 clinical isolate 5448. Both strains induced the expression of genes encoding a wide range of inflammatory mediators, including IL-8. Pathway analysis revealed differentially expressed genes between mock and JRS4- or 5448-infected TEpi cells were enriched in transcription factor networks that regulate IL-8 expression, such as AP-1, ATF-2, and NFAT. While JRS4 infection resulted in high levels of secreted IL-8, 5448 infection did not, suggesting that 5448 may post-transcriptionally dampen IL-8 production. Infection with 5448ΔcepA, an isogenic mutant lacking the IL-8 protease SpyCEP, resulted in IL-8 secretion levels comparable to JRS4 infection. Complementation of 5448ΔcepA and JRS4 with a plasmid encoding 5448-derived SpyCEP significantly reduced IL-8 secretion by TEpi cells. Our results suggest that intracellular infection with the pathogenic GAS M1T1 clone induces a strong pro-inflammatory response in primary tonsil epithelial cells, but modulates this host response by selectively degrading the neutrophil-recruiting chemokine IL-8 to benefit infection.
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Affiliation(s)
- Amelia T. Soderholm
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Timothy C. Barnett
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
- Wesfarmers Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Perth, WA, Australia
| | - Othmar Korn
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Brisbane, QLD, Australia
| | - Tania Rivera-Hernandez
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Lisa M. Seymour
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
| | - Benjamin L. Schulz
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
| | - Victor Nizet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Christine A. Wells
- Centre for Stem Cell Systems, University of Melbourne, Melbourne, VIC, Australia
| | - Matthew J. Sweet
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience and IMB Centre for Inflammation and Disease Research, University of Queensland, Brisbane, QLD, Australia
| | - Mark J. Walker
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, Australia
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19
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Crawford MA, Margulieux KR, Singh A, Nakamoto RK, Hughes MA. Mechanistic insights and therapeutic opportunities of antimicrobial chemokines. Semin Cell Dev Biol 2018; 88:119-128. [PMID: 29432954 PMCID: PMC6613794 DOI: 10.1016/j.semcdb.2018.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/06/2018] [Indexed: 12/27/2022]
Abstract
Chemokines are a family of small proteins best known for their ability to orchestrate immune cell trafficking and recruitment to sites of infection. Their role in promoting host defense is multiplied by a number of additional receptor-dependent biological activities, and most, but not all, chemokines have been found to mediate direct antimicrobial effects against a broad range of microorganisms. The molecular mechanism(s) by which antimicrobial chemokines kill bacteria remains unknown; however, recent observations have expanded our fundamental understanding of chemokine-mediated bactericidal activity to reveal increasingly diverse and complex actions. In the current review, we present and consider mechanistic insights of chemokine-mediated antimicrobial activity against bacteria. We also discuss how contemporary advances are reshaping traditional paradigms and opening up new and innovative avenues of research with translational implications. Towards this end, we highlight a developing framework for leveraging chemokine-mediated bactericidal and immunomodulatory effects to advance pioneering therapeutic approaches for treating bacterial infections, including those caused by multidrug-resistant pathogens.
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Affiliation(s)
- Matthew A Crawford
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Katie R Margulieux
- Department of Enteric Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - Arpita Singh
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA
| | - Robert K Nakamoto
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, 22908, USA
| | - Molly A Hughes
- Division of Infectious Diseases & International Health, Department of Medicine, University of Virginia, Charlottesville, VA, 22908, USA.
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20
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Serum Cytokine Profiles in Patients with Dengue Fever at the Acute Infection Phase. DISEASE MARKERS 2018; 2018:8403937. [PMID: 29651328 PMCID: PMC5831957 DOI: 10.1155/2018/8403937] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/22/2017] [Accepted: 01/02/2018] [Indexed: 02/06/2023]
Abstract
Background Dengue virus (DENV) is transmitted by mosquito and has been circulating in Guangdong, China, for over 30 years. Dengue infection causes mild to severe disease symptoms in human. Cytokine profiles were suggested to be crucial especially during the acute stage in the dengue infection. Aim To determine the cytokine profiles at the acute stage in patients with primary or secondary dengue infection in Guangzhou city in the 2014 outbreak. Methods We investigated 23 inflammatory cytokines in serum collected from dengue-infected patients and analyzed their correlations with their clinical indexes. Results The concentrations of CXCL9, IP-10, CXCL11, IL-8, IL-10, and CCL2 in serum were significantly higher in the groups of DENV-infected patients during the first two weeks than those of control group while CCL17 and CXCL5 showed lower expression level in the patients. Among these cytokines, CXCL9, CCL17, and CXCL5 showed statistical difference between the groups of primary and secondary infections. The platelet count and lactate dehydrogenase were correlated with the level of CCL17 and MIP-1α/CXCL5, respectively, in the group of secondary infection. Conclusions We determined the cytokine profiles in serum of the patients during the 2014 dengue outbreak. The expression of specific cytokines was associated with the secondary infection.
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21
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Metzemaekers M, Vanheule V, Janssens R, Struyf S, Proost P. Overview of the Mechanisms that May Contribute to the Non-Redundant Activities of Interferon-Inducible CXC Chemokine Receptor 3 Ligands. Front Immunol 2018; 8:1970. [PMID: 29379506 PMCID: PMC5775283 DOI: 10.3389/fimmu.2017.01970] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/20/2017] [Indexed: 12/17/2022] Open
Abstract
The inflammatory chemokines CXCL9, CXCL10, and CXCL11 are predominantly induced by interferon (IFN)-γ and share an exclusive chemokine receptor named CXC chemokine receptor 3 (CXCR3). With a prototype function of directing temporal and spatial migration of activated T cells and natural killer cells, and inhibitory effects on angiogenesis, these CXCR3 ligands have been implicated in infection, acute inflammation, autoinflammation and autoimmunity, as well as in cancer. Intense former research efforts led to recent and ongoing clinical trials using CXCR3 and CXCR3 ligand targeting molecules. Scientific evidence has claimed mutual redundancy, ligand dominance, collaboration or even antagonism, depending on the (patho)physiological context. Most research on their in vivo activity, however, illustrates that CXCL9, CXCL10, and CXCL11 each contribute to the activation and trafficking of CXCR3 expressing cells in a non-redundant manner. When looking into detail, one can unravel a multistep machinery behind final CXCR3 ligand functions. Not only can specific cell types secrete individual CXCR3 interacting chemokines in response to certain stimuli, but also the receptor and glycosaminoglycan interactions, major associated intracellular pathways and susceptibility to processing by particular enzymes, among others, seem ligand-specific. Here, we overview major aspects of the molecular properties and regulatory mechanisms of IFN-induced CXCR3 ligands, and propose that their in vivo non-redundancy is a reflection of the unprecedented degree of versatility that seems inherent to the IFN-related CXCR3 chemokine system.
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Affiliation(s)
- Mieke Metzemaekers
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
| | - Vincent Vanheule
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
| | - Rik Janssens
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
| | - Sofie Struyf
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
| | - Paul Proost
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium
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22
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Stocks CJ, Schembri MA, Sweet MJ, Kapetanovic R. For when bacterial infections persist: Toll-like receptor-inducible direct antimicrobial pathways in macrophages. J Leukoc Biol 2018; 103:35-51. [PMID: 29345056 DOI: 10.1002/jlb.4ri0917-358r] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 10/19/2017] [Accepted: 10/19/2017] [Indexed: 12/18/2022] Open
Abstract
Macrophages are linchpins of innate immunity, responding to invading microorganisms by initiating coordinated inflammatory and antimicrobial programs. Immediate antimicrobial responses, such as NADPH-dependent reactive oxygen species (ROS), are triggered upon phagocytic receptor engagement. Macrophages also detect and respond to microbial products through pattern recognition receptors (PRRs), such as TLRs. TLR signaling influences multiple biological processes including antigen presentation, cell survival, inflammation, and direct antimicrobial responses. The latter enables macrophages to combat infectious agents that persist within the intracellular environment. In this review, we summarize our current understanding of TLR-inducible direct antimicrobial responses that macrophages employ against bacterial pathogens, with a focus on emerging evidence linking TLR signaling to reprogramming of mitochondrial functions to enable the production of direct antimicrobial agents such as ROS and itaconic acid. In addition, we describe other TLR-inducible antimicrobial pathways, including autophagy/mitophagy, modulation of nutrient availability, metal ion toxicity, reactive nitrogen species, immune GTPases (immunity-related GTPases and guanylate-binding proteins), and antimicrobial peptides. We also describe examples of mechanisms of evasion of such pathways by professional intramacrophage pathogens, with a focus on Salmonella, Mycobacteria, and Listeria. An understanding of how TLR-inducible direct antimicrobial responses are regulated, as well as how bacterial pathogens subvert such pathways, may provide new opportunities for manipulating host defence to combat infectious diseases.
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Affiliation(s)
- Claudia J Stocks
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark A Schembri
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
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A longitudinal analysis of the vaginal microbiota and vaginal immune mediators in women from sub-Saharan Africa. Sci Rep 2017; 7:11974. [PMID: 28931859 PMCID: PMC5607244 DOI: 10.1038/s41598-017-12198-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/05/2017] [Indexed: 12/12/2022] Open
Abstract
In cross-sectional studies increased vaginal bacterial diversity has been associated with vaginal inflammation which can be detrimental for health. We describe longitudinal changes at 5 visits over 8 weeks in vaginal microbiota and immune mediators in African women. Women (N = 40) with a normal Nugent score at all visits had a stable lactobacilli dominated microbiota with prevailing Lactobacillus iners. Presence of prostate-specific antigen (proxy for recent sex) and being amenorrhoeic (due to progestin-injectable use), but not recent vaginal cleansing, were significantly associated with microbiota diversity and inflammation (controlled for menstrual cycle and other confounders). Women (N = 40) with incident bacterial vaginosis (Nugent 7-10) had significantly lower concentrations of lactobacilli and higher concentrations of Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia, at the incident visit and when concentrations of proinflammatory cytokines (IL-1β, IL-12p70) were increased and IP-10 and elafin were decreased. A higher 'composite-qPCR vaginal-health-score' was directly associated with decreased concentrations of proinflammatory cytokines (IL-1α, IL-8, IL-12(p70)) and increased IP-10. This longitudinal study confirms the inflammatory nature of vaginal dysbiosis and its association with recent vaginal sex and progestin-injectable use. A potential role for proinflammatory mediators and IP-10 in combination with the vaginal-health-score as predictive biomarkers for vaginal dysbiosis merits further investigation.
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Mesenchymal Stem Cell Secretome: Toward Cell-Free Therapeutic Strategies in Regenerative Medicine. Int J Mol Sci 2017; 18:ijms18091852. [PMID: 28841158 PMCID: PMC5618501 DOI: 10.3390/ijms18091852] [Citation(s) in RCA: 724] [Impact Index Per Article: 103.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 02/07/2023] Open
Abstract
Earlier research primarily attributed the effects of mesenchymal stem cell (MSC) therapies to their capacity for local engrafting and differentiating into multiple tissue types. However, recent studies have revealed that implanted cells do not survive for long, and that the benefits of MSC therapy could be due to the vast array of bioactive factors they produce, which play an important role in the regulation of key biologic processes. Secretome derivatives, such as conditioned media or exosomes, may present considerable advantages over cells for manufacturing, storage, handling, product shelf life and their potential as a ready-to-go biologic product. Nevertheless, regulatory requirements for manufacturing and quality control will be necessary to establish the safety and efficacy profile of these products. Among MSCs, human uterine cervical stem cells (hUCESCs) may be a good candidate for obtaining secretome-derived products. hUCESCs are obtained by Pap cervical smear, which is a less invasive and painful method than those used for obtaining other MSCs (for example, from bone marrow or adipose tissue). Moreover, due to easy isolation and a high proliferative rate, it is possible to obtain large amounts of hUCESCs or secretome-derived products for research and clinical use.
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Cossio-Ayala M, Domínguez-López M, Mendez-Enriquez E, Portillo-Téllez MDC, García-Hernández E. In vitro and in vivo antimicrobial activity of a synthetic peptide derived from the C-terminal region of human chemokine CCL13 against Pseudomonas aeruginosa. Peptides 2017; 94:49-55. [PMID: 28687455 DOI: 10.1016/j.peptides.2017.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 01/12/2023]
Abstract
Chemokines are important mediators of immunological responses during inflammation and under steady-state conditions. In addition to regulating cell migration, some chemotactic cytokines have direct effects on bacteria. Here, we characterized the antibacterial ability of the synthetic oligopeptide CCL1357-75, which corresponds to the carboxyl-terminal region of the human chemokine CCL13. In vitro measurements indicated that CCL1357-75 disrupts the cell membrane of Pseudomonas aeruginosa through a mechanism coupled to an unordered-helicoidal conformational transition. In a murine pneumonic model, CCL1357-75 improved mouse survival and bacterial clearance and decreased neutrophil recruitment, proinflammatory cytokines and lung pathology compared with that observed in untreated infected animals. Overall, our study supports the ability of chemokines and/or chemokine-derived oligopeptides to act as direct defense agents against pathogenic bacteria and suggests their potential use as alternative antibiotics.
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Affiliation(s)
- Mayte Cossio-Ayala
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04630, D.F., Mexico; Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04630, D.F., Mexico
| | - Mariana Domínguez-López
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04630, D.F., Mexico
| | - Erika Mendez-Enriquez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04630, D.F., Mexico
| | | | - Enrique García-Hernández
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04630, D.F., Mexico.
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Glycosaminoglycans Regulate CXCR3 Ligands at Distinct Levels: Protection against Processing by Dipeptidyl Peptidase IV/CD26 and Interference with Receptor Signaling. Int J Mol Sci 2017; 18:ijms18071513. [PMID: 28703769 PMCID: PMC5536003 DOI: 10.3390/ijms18071513] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022] Open
Abstract
CXC chemokine ligand (CXCL)9, CXCL10 and CXCL11 direct chemotaxis of mainly T cells and NK cells through activation of their common CXC chemokine receptor (CXCR)3. They are inactivated upon NH2-terminal cleavage by dipeptidyl peptidase IV/CD26. In the present study, we found that different glycosaminoglycans (GAGs) protect the CXCR3 ligands against proteolytic processing by CD26 without directly affecting the enzymatic activity of CD26. In addition, GAGs were shown to interfere with chemokine-induced CXCR3 signaling. The observation that heparan sulfate did not, and heparin only moderately, altered CXCL10-induced T cell chemotaxis in vitro may be explained by a combination of protection against proteolytic inactivation and altered receptor interaction as observed in calcium assays. No effect of CD26 inhibition was found on CXCL10-induced chemotaxis in vitro. However, treatment of mice with the CD26 inhibitor sitagliptin resulted in an enhanced CXCL10-induced lymphocyte influx into the joint. This study reveals a dual role for GAGs in modulating the biological activity of CXCR3 ligands. GAGs protect the chemokines from proteolytic cleavage but also directly interfere with chemokine–CXCR3 signaling. These data support the hypothesis that both GAGs and CD26 affect the in vivo chemokine function.
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Holdren GO, Rosenthal DJ, Yang J, Bates AM, Fischer CL, Zhang Y, Brogden NK, Brogden KA. Antimicrobial Activity of Chemokine CXCL10 for Dermal and Oral Microorganisms. Antibiotics (Basel) 2016; 3:527-39. [PMID: 25859394 PMCID: PMC4387564 DOI: 10.3390/antibiotics3040527] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
CXCL10 (IP-10) is a small 10 kDa chemokine with antimicrobial activity. It is induced by IFN-γ, chemoattracts mononuclear cells, and promotes adhesion of T cells. Recently, we detected CXCL10 on the surface of the skin and in the oral cavity. In the current study, we used broth microdilution and radial diffusion assays to show that CXCL10 inhibits the growth of Escherichia coli, Staphylococcus aureus, Corynebacterium jeikeium, Corynebacterium striatum, and Candida albicans HMV4C, but not Corynebacterium bovis, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Poryphromonas gingivalis, or C. albicans ATCC 64124. The reason for the selective antimicrobial activity is not yet known. However, antimicrobial activity of CXCL10 may be related to its composition and structure, as a cationic 98 amino acid residue molecule with 10 lysine residues, 7 arginine residues, a total net charge of +11, and a theoretical pI of 9.93. Modeling studies revealed that CXCL10 contains an α-helix at the N-terminal, three anti-parallel β-strands in the middle, and an α-helix at the C-terminal. Thus, CXCL10, when produced on the surface of the skin or in the oral cavity, likely has antimicrobial activity and may enhance innate antimicrobial and cellular responses to the presence of select commensal or opportunistic microorganisms.
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Affiliation(s)
- Grant O. Holdren
- Division of Pharmaceutics and Translational Therapeutics, Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (G.O.H.); (N.K.B.)
| | - David J. Rosenthal
- Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (D.J.R.); (A.M.B.); (C.L.F.)
| | - Jianyi Yang
- Department of Computational Medicine and Bioinformatics, The University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA; E-Mails: (J.Y.); (Y.Z.)
| | - Amber M. Bates
- Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (D.J.R.); (A.M.B.); (C.L.F.)
| | - Carol L. Fischer
- Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (D.J.R.); (A.M.B.); (C.L.F.)
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, The University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA; E-Mails: (J.Y.); (Y.Z.)
| | - Nicole K. Brogden
- Division of Pharmaceutics and Translational Therapeutics, Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (G.O.H.); (N.K.B.)
| | - Kim A. Brogden
- Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (D.J.R.); (A.M.B.); (C.L.F.)
- Periodontics, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-319-335-8077; Fax: +1-319-335-8895
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Vanheule V, Vervaeke P, Mortier A, Noppen S, Gouwy M, Snoeck R, Andrei G, Van Damme J, Liekens S, Proost P. Basic chemokine-derived glycosaminoglycan binding peptides exert antiviral properties against dengue virus serotype 2, herpes simplex virus-1 and respiratory syncytial virus. Biochem Pharmacol 2015; 100:73-85. [PMID: 26551597 DOI: 10.1016/j.bcp.2015.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/02/2015] [Indexed: 12/12/2022]
Abstract
Chemokines attract leukocytes to sites of infection in a G protein-coupled receptor (GPCR) and glycosaminoglycan (GAG) dependent manner. Therefore, chemokines are crucial molecules for proper functioning of our antimicrobial defense mechanisms. In addition, some chemokines have GPCR-independent defensin-like antimicrobial activities against bacteria and fungi. Recently, high affinity for GAGs has been reported for the positively charged COOH-terminal region of the chemokine CXCL9. In addition to CXCL9, also CXCL12γ has such a positively charged COOH-terminal region with about 50% positively charged amino acids. In this report, we compared the affinity of COOH-terminal peptides of CXCL9 and CXCL12γ for GAGs and KD values in the low nM range were detected. Several enveloped viruses such as herpesviruses, hepatitis viruses, human immunodeficiency virus (HIV), dengue virus (DENV), etc. are known to bind to GAGs such as the negatively charged heparan sulfate (HS). In this way GAGs are important for the initial contacts between viruses and host cells and for the infection of the cell. Thus, inhibiting the virus-cell interactions, by blocking GAG-binding sites on the host cell, might be a way to target multiple virus families and resistant strains. This article reports that the COOH-terminal peptides of CXCL9 and CXCL12γ have antiviral activity against DENV serotype 2, clinical and laboratory strains of herpes simplex virus (HSV)-1 and respiratory syncytial virus (RSV). Moreover, we show that CXCL9(74-103) competes with DENV envelope protein domain III for binding to heparin. These short chemokine-derived peptides may be lead molecules for the development of novel antiviral agents.
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Affiliation(s)
- Vincent Vanheule
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Immunology, B-3000 Leuven, Belgium.
| | - Peter Vervaeke
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium.
| | - Anneleen Mortier
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Immunology, B-3000 Leuven, Belgium.
| | - Sam Noppen
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium.
| | - Mieke Gouwy
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Immunology, B-3000 Leuven, Belgium.
| | - Robert Snoeck
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium.
| | - Graciela Andrei
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium.
| | - Jo Van Damme
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Immunology, B-3000 Leuven, Belgium.
| | - Sandra Liekens
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium.
| | - Paul Proost
- KU Leuven, University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Immunology, B-3000 Leuven, Belgium.
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Cross-Sectional Analysis of Selected Genital Tract Immunological Markers and Molecular Vaginal Microbiota in Sub-Saharan African Women, with Relevance to HIV Risk and Prevention. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:526-38. [PMID: 25761460 DOI: 10.1128/cvi.00762-14] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/08/2015] [Indexed: 01/08/2023]
Abstract
Data on immune mediators in the genital tract and the factors that modulate them in sub-Saharan women are limited. Cervicovaginal lavage (CVL) samples from 430 sexually active women from Kenya, South Africa, and Rwanda were analyzed for 12 soluble immune mediators using Bio-Plex and Meso Scale Discovery multiplex platforms, as well as single enzyme-linked immunosorbent assays. Ten bacterial species were quantified in vaginal swab samples. Bacterial vaginosis (BV) was defined by Nugent scoring. CVL samples from HIV-infected women showed a clear-cut proinflammatory profile. Pregnant women, adolescents, and women engaging in traditional vaginal practices differed in specific soluble markers compared to reference groups of adult HIV-negative women. Cervical mucus, cervical ectopy, abnormal vaginal discharge, and having multiple sex partners were each associated with an increase in inflammatory mediators. The levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12(p70), and IL-8 were elevated, whereas the IL-1RA/IL-1(α+β) ratio decreased in women with BV. The level of gamma interferon-induced protein 10 was lower in BV-positive than in BV-negative women, suggesting its suppression as a potential immune evasion mechanism by BV-associated bacteria. Lactobacillus crispatus and Lactobacillus vaginalis were associated with decreased proinflammatory cytokines and each BV-associated species with increased proinflammatory cytokines. Remarkably, the in vitro anti-HIV activity of CVL samples from BV-positive women was stronger than that of BV-negative women. In conclusion, we found significant associations of factors, including vaginal microbiota, which can influence immune mediators in the vaginal environment in sexually active women. These factors need to be considered when establishing normative levels or pathogenic cutoffs of biomarkers of inflammation and associated risks in African women.
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Pathogenic Escherichia coli and lipopolysaccharide enhance the expression of IL-8, CXCL5, and CXCL10 in canine endometrial stromal cells. Theriogenology 2015; 84:34-42. [PMID: 25765298 DOI: 10.1016/j.theriogenology.2015.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/05/2015] [Accepted: 02/05/2015] [Indexed: 01/05/2023]
Abstract
Chemokines play a central role in cellular communication in response to bacterial infection. However, the knowledge of the chemokine responses to bacterial infections in dogs remains limited. Uterine bacterial infection (pyometra) is one of the most common bacterial diseases in dogs and causes sepsis in most of the cases. We have shown previously that dogs with pyometra have higher messenger RNA (mRNA) levels of chemokines in uterus. To assess whether the stromal part of the endometrium expresses chemokines in response to bacterial infection, we cultured endometrial stromal cells isolated from healthy dogs and exposed them to either live pathogenic Escherichia coli, isolated from the uterus of a dog with pyometra, or lipopolysaccharide. Changes in the mRNA expression of ELR(+) CXC chemokines, IL-8, CXCL5, CXCL7, and ELR(-) CXC chemokine, CXCL10, were measured after 24 hours using quantitative real-time polymerase chain reaction. Levels of IL-8, CXCL5, and CXCL10 were upregulated in endometrial stromal cells exposed to E coli and lipopolysaccharide, whereas the level of CXCL7 was decreased or unaffected. In addition, levels of IL-8 and CXCL5, but not CXCL7 or CXCL10, were significantly higher in dogs with pyometra than those in healthy dogs. Our findings show that pathogenic uterine-derived E coli induces a CXC chemokine response both in cultured endometrial stromal cells within 24 hours and in pyometra-affected uteri from dogs. Stromal cells could therefore play an important role in early neutrophil and T cell recruitment to the site of inflammation during gram-negative bacterial infection of the uterus. Further studies are needed to clarify the role of chemokines in host response to bacterial infection in dogs and the possibility of using chemokines as diagnostic parameters for bacterial infection in this species.
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Reid-Yu SA, Tuinema BR, Small CN, Xing L, Coombes BK. CXCL9 contributes to antimicrobial protection of the gut during citrobacter rodentium infection independent of chemokine-receptor signaling. PLoS Pathog 2015; 11:e1004648. [PMID: 25643352 PMCID: PMC4333760 DOI: 10.1371/journal.ppat.1004648] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/30/2014] [Indexed: 12/20/2022] Open
Abstract
Chemokines have been shown to be effective bactericidal molecules against a variety of bacteria and fungi in vitro. These direct antimicrobial effects are independent of their chemotactic activities involving immunological receptors. However, the direct biological role that these proteins may play in host defense, particularly against intestinal pathogens, is poorly understood. Here, we show that CXCL9, an ELR- chemokine, exhibits direct antimicrobial activity against Citrobacter rodentium, an attaching/effacing pathogen that infects the gut mucosa. Inhibition of this antimicrobial activity in vivo using anti-CXCL9 antibodies increases host susceptibility to C. rodentium infection with pronounced bacterial penetration into crypts, increased bacterial load, and worsened tissue pathology. Using Rag1-/- mice and CXCR3-/- mice, we demonstrate that the role for CXCL9 in protecting the gut mucosa is independent of an adaptive response or its immunological receptor, CXCR3. Finally, we provide evidence that phagocytes function in tandem with NK cells for robust CXCL9 responses to C. rodentium. These findings identify a novel role for the immune cell-derived CXCL9 chemokine in directing a protective antimicrobial response in the intestinal mucosa. Host defense peptides are an essential part of the innate immune response to pathogens, particularly at mucosal surfaces. Some chemokines, previously known for their ability to recruit immune cells to a site of inflammation, have been identified to have direct antimicrobial activity in vitro against a variety of pathogens. Despite this, it was unknown whether chemokines play a role in protecting the gut mucosa against enteric pathogens, independent of their immunological receptors. Using a mouse model of enteric pathogen infection with both wild type mice and genetic knockouts, we showed that the chemokine CXCL9 has direct antimicrobial activity against pathogen infection. This antimicrobial activity prevented the invasion of bacteria into intestinal crypts, thus protecting the host from immunopathology. Neutralization of this CXCL9-dependent antimicrobial activity increased host susceptibility to infection, leading to bacterial penetration into intestinal crypts and increased tissue pathology. These data support the importance of a receptor-independent role for chemokines in host defense at mucosal surfaces and may offer alternative treatment strategies for infections, particularly in regards to organisms that are resistant to conventional antibiotics.
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Affiliation(s)
- Sarah A. Reid-Yu
- Michael G. DeGroote Institute for Infectious Disease Research, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Brian R. Tuinema
- Michael G. DeGroote Institute for Infectious Disease Research, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Cherrie N. Small
- Michael G. DeGroote Institute for Infectious Disease Research, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Lydia Xing
- Michael G. DeGroote Institute for Infectious Disease Research, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Brian K. Coombes
- Michael G. DeGroote Institute for Infectious Disease Research, Hamilton, Ontario, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
- * E-mail:
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Wen YT, Wang JS, Tsai SH, Chuan CN, Wu JJ, Liao PC. Label-free proteomic analysis of environmental acidification-influenced Streptococcus pyogenes secretome reveals a novel acid-induced protein histidine triad protein A (HtpA) involved in necrotizing fasciitis. J Proteomics 2014; 109:90-103. [DOI: 10.1016/j.jprot.2014.06.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 06/11/2014] [Accepted: 06/26/2014] [Indexed: 10/25/2022]
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Jovic S, Shikhagaie M, Mörgelin M, Kjellström S, Erjefalt J, Olin AI, Frick IM, Egesten A. Expression of MIG/CXCL9 in cystic fibrosis and modulation of its activities by elastase of Pseudomonas aeruginosa. J Innate Immun 2014; 6:846-59. [PMID: 25115612 DOI: 10.1159/000365399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 06/22/2014] [Indexed: 12/20/2022] Open
Abstract
In cystic fibrosis (CF), colonization of the airways with Pseudomonas aeruginosa is associated with disease deterioration. The mechanism behind the disease progression is not fully understood. The present work shows that the antibacterial chemokine MIG/CXCL9 is present in the airways and in sputum of CF patients. MIG/CXCL9 showed high bactericidal activity against. P. aeruginosa, including some strains from the airways of CF patients. Full-length MIG/CXCL9 was detected in sputum from healthy controls and CF patients colonized with P. aeruginosa. However, degraded MIG/CXCL9 was only found in CF sputum. In vitro, elastase of P. aeruginosa cleaved off a fragment of similar size and two additional fragments from MIG/CXCL9. The fragments showed less bactericidal activity against P. aeruginosa compared with the full-length protein. The fragments did not activate the MIG/CXCL9 receptor CXCR3 (expressed e.g. by NK cells, mast cells, and activated T cells) but instead displayed noncompetitive inhibition. In vitro, a decrease in CXCR3-bearing cells was found within and in the proximity of the bronchial epithelium of CF lung tissue compared with controls. Taken together, both bactericidal and cell-recruiting activities of MIG/CXCL9 are corrupted by P. aeruginosa through release of elastase, and this may contribute to impaired airway host defense in CF.
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Affiliation(s)
- Sandra Jovic
- Sections for Respiratory Medicine and Allergology, Department of Clinical Sciences, Lund University, Lund, Sweden
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Berri M, Virlogeux-Payant I, Chevaleyre C, Melo S, Zanello G, Salmon H, Meurens F. CCL28 involvement in mucosal tissues protection as a chemokine and as an antibacterial peptide. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 44:286-290. [PMID: 24445014 DOI: 10.1016/j.dci.2014.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/03/2014] [Indexed: 06/03/2023]
Abstract
CCL28 chemokine is expressed by epithelial cells of various mucosal tissues. This chemokine binds to CCR3 and CCR10 receptors and plays an essential role in the IgA antibody secreting cells (IgA-ASC) homing to mucosal surfaces and to lactating mammary gland as well. In addition, CCL28 has been shown to exert a potent antimicrobial activity against both Gram-negative and Gram-positive bacteria and fungi. Using the pig model, we investigated the expression of both CCR10 and CCR3 receptors in a large panel of mucosal tissues. RT-PCR analysis revealed the expression of CCR3 and CCR10 mRNA in salivary glands, nasal mucosae, Peyer's patches, small and large intestine, suggesting the presence of leucocytes expressing these receptors within these tissues. CCR10 mRNA was observed in sow mammary gland at late gestation with an increasing level during lactation. Recombinant porcine CCL28 protein was produced and mass spectrometry analysis revealed antimicrobial chemokines features such as a high pI value (10.2) and a C-terminal highly positively-charged region. Using a viable count assay, we showed that CCL28 displayed antimicrobial activity against enteric pathogens and was effective in killing Salmonella serotypes Dublin and Choleraesuis, enteroinvasive Escherichia coli K88 and non-pathogenic E. Coli K12. The potent antimicrobial function of CCL28 combined with its wide distribution in mucosal tissues and secretions suggest that this protein plays an important role in innate immune protection of the epithelial surfaces.
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Affiliation(s)
- Mustapha Berri
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| | | | - Claire Chevaleyre
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| | - Sandrine Melo
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| | - Galliano Zanello
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| | - Henri Salmon
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
| | - François Meurens
- INRA Centre de Val de Loire, UMR-1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France.
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DrsG from Streptococcus dysgalactiae subsp. equisimilis inhibits the antimicrobial peptide LL-37. Infect Immun 2014; 82:2337-44. [PMID: 24664506 DOI: 10.1128/iai.01411-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SIC and DRS are related proteins present in only 4 of the >200 Streptococcus pyogenes emm types. These proteins inhibit complement-mediated lysis and/or the activity of certain antimicrobial peptides (AMPs). A gene encoding a homologue of these proteins, herein called DrsG, has been identified in the related bacterium Streptococcus dysgalactiae subsp. equisimilis. Here we show that geographically dispersed isolates representing 14 of 50 emm types examined possess variants of drsG. However, not all isolates within the drsG-positive emm types possess the gene. Sequence comparisons also revealed a high degree of conservation in different S. dysgalactiae subsp. equisimilis emm types. To examine the biological activity of DrsG, recombinant versions of two major DrsG variants, DrsGS and DrsGL, were expressed and purified. Western blot analysis using antisera raised to these proteins demonstrated both variants to be expressed and secreted into culture supernatants. Unlike SIC, but similar to DRS, DrsG does not inhibit complement-mediated lysis. However, like both SIC and DRS, DrsG is a ligand of the cathelicidin LL-37 and is inhibitory to its bactericidal activity in in vitro assays. Conservation of prolines in the C-terminal region also suggests that these residues are important in the biology of this family of proteins. This is the first report demonstrating the activity of an AMP-inhibitory protein in S. dysgalactiae subsp. equisimilis and suggests that inhibition of AMP activity is the primary function of this family of proteins. The acquisition of the complement-inhibitory activity of SIC may reflect its continuing evolution.
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Gela A, Jovic S, Nordin SL, Egesten A. Midkine in host defence. Br J Pharmacol 2014; 171:859-69. [PMID: 24024937 PMCID: PMC3925024 DOI: 10.1111/bph.12402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/27/2013] [Accepted: 09/02/2013] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED Midkine (MK) shares several features in common with antibacterial proteins of the innate immune system. These include growth factor properties, heparin-binding regions and effects on immune cells, such as recruitment and activation of neutrophils and macrophages. Indeed, recent research has demonstrated potent bactericidal and fungicidal activities of MK. This protein is constitutively expressed at relevant concentrations at barriers of the body, such as the skin and the large airways, where the body first encounters potential pathogens. The antibacterial properties of MK orthologues are preserved during evolution, as exemplified by miple2 of Drosophila. In addition to retinoic acid, promoters of MK gene expression include factors present at sites of infection, reactive oxygen species, activation of the transcription factor NF-κB and hypoxia. In the light of the development of resistance in pathogenic bacteria to conventional antibiotics, MK is an interesting molecule that could serve as a template in developing novel therapeutic strategies against bacterial and fungal infections, either alone or in combination with conventional antibiotics. LINKED ARTICLES This article is part of a themed section on Midkine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-4.
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Affiliation(s)
- A Gela
- Section for Respiratory Medicine & Allergology, Department of Clinical Sciences Lund Skåne University Hospital, Lund UniversityLund, Sweden
| | - S Jovic
- Section for Respiratory Medicine & Allergology, Department of Clinical Sciences Lund Skåne University Hospital, Lund UniversityLund, Sweden
| | - S L Nordin
- Section for Respiratory Medicine & Allergology, Department of Clinical Sciences Lund Skåne University Hospital, Lund UniversityLund, Sweden
| | - A Egesten
- Section for Respiratory Medicine & Allergology, Department of Clinical Sciences Lund Skåne University Hospital, Lund UniversityLund, Sweden
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37
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Murphy EC, Mohanty T, Frick IM. FAF and SufA: proteins of Finegoldia magna that modulate the antibacterial activity of histones. J Innate Immun 2013; 6:394-404. [PMID: 24335013 DOI: 10.1159/000356432] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 10/14/2013] [Indexed: 11/19/2022] Open
Abstract
Many bacterial pathogens have developed methods to overcome the defences of the host innate immune system. One such defence is the release of antimicrobial peptides (AMPs). Histones have been found to function as AMPs, in addition to their main biological function of packaging and organising DNA into nucleosomes. In this study, the Gram-positive anaerobic coccus Finegoldia magna was found to bind histones by Western blot and immunoprecipitation analysis. F. magna, which is normally a commensal of the skin and mucous membranes, is also known to act as an opportunistic pathogen and has been isolated from various clinical infection sites. It was found to bind to histones extracted from human skin epidermis through its surface and extracellular adhesion protein FAF. Through FAF binding, F. magna was protected from histone bactericidal activity. Furthermore, the histones were found to be degraded by SufA, a subtilisin-like extracellular serine protease of F. magna. Hence, the results of the present study will give more insight into how F. magna persists both as a commensal organism at the basement membrane of the skin and as an opportunistic pathogen during infection.
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Affiliation(s)
- Elizabeth C Murphy
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
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38
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Wollein Waldetoft K, Karlsson C, Gram M, Malmström J, Mörgelin M, Frick IM, Björck L. Surface proteins of group G Streptococcus in different phases of growth: patterns of production and implications for the host-bacteria relationship. MICROBIOLOGY-SGM 2013; 160:279-286. [PMID: 24222616 DOI: 10.1099/mic.0.071332-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Group G Streptococcus (GGS) is a human bacterial pathogen expressing surface proteins FOG and protein G (PG) which interact with several host defence systems, including the complement and contact systems. Selected reaction monitoring mass spectrometry, electron microscopy and protein binding assays were used to track the amounts of FOG and PG intracellularly and on the bacterial surface during different phases of growth. Large and increasing amounts of PG were present on the surface in the stationary growth phase, and this was due to de novo production. In contrast, the amount of FOG did not change substantially during this phase. Apart from PG, a number of housekeeping proteins also increased in abundance in the stationary phase. These results show that GGS protein production is active during the stationary phase and that the bacteria actively remodel their surface and enter a less pro-inflammatory state in this phase.
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Affiliation(s)
| | - Christofer Karlsson
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Magnus Gram
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Matthias Mörgelin
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Inga-Maria Frick
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Lars Björck
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
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Denner J, Eschricht M, Lauck M, Semaan M, Schlaermann P, Ryu H, Akyüz L. Modulation of cytokine release and gene expression by the immunosuppressive domain of gp41 of HIV-1. PLoS One 2013; 8:e55199. [PMID: 23383108 PMCID: PMC3559347 DOI: 10.1371/journal.pone.0055199] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 12/19/2012] [Indexed: 11/18/2022] Open
Abstract
The transmembrane envelope protein gp41 of the human immunodeficiency virus HIV-1 plays an important role during infection allowing fusion of the viral and cellular membrane. In addition, there is increasing evidence that gp41 may contribute to the immunodeficiency induced by HIV-1. Recombinant gp41 and a synthetic peptide corresponding to a highly conserved domain in gp41, the immunosuppressive (isu) domain, have been shown to inhibit mitogen-induced activation of human peripheral blood mononuclear cells (PBMCs) and to increase release of IL-6 and IL-10 from these cells. We recently reported that a single mutation in the isu domain of gp41 abrogated the immunosuppressive properties and that HIV-1 sequences containing such abrogating mutations had never been isolated from infected individuals. Here, we studied the influence of the isu peptide on the release of 66 cytokines and the expression of 27,000 genes in PBMCs. Incubation of PBMCs with isu peptide homopolymers increased the expression of 16 cytokines among them IL-6 and IL-10, and decreased that of IL-2 and CXCL9. Interestingly, the extend of cytokine modulation was donor-dependent. Among the genes up-regulated were IL-6, IL-8, IL-10 but also MMP-1, TREM-1 and IL-1beta. Most importantly, genes involved in innate immunity such as FCN1 and SEPP1 were found down-regulated. Many changes in cytokine expression demonstrated in our experiments were also found in HIV-1 infected individuals. These data indicate that the isu domain of gp41 has a broad impact on gene expression and cytokine release and therefore may be involved in HIV-1 induced immunopathogenesis.
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40
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Nguyen LT, Vogel HJ. Structural perspectives on antimicrobial chemokines. Front Immunol 2012; 3:384. [PMID: 23293636 PMCID: PMC3531597 DOI: 10.3389/fimmu.2012.00384] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 11/30/2012] [Indexed: 12/14/2022] Open
Abstract
Chemokines are best known as signaling proteins in the immune system. Recently however, a large number of human chemokines have been shown to exert direct antimicrobial activity. This moonlighting activity appears to be related to the net high positive charge of these immune signaling proteins. Chemokines can be divided into distinct structural elements and some of these have been studied as isolated peptide fragments that can have their own antimicrobial activity. Such peptides often encompass the α-helical region found at the C-terminal end of the parent chemokines, which, similar to other antimicrobial peptides, adopt a well-defined membrane-bound amphipathic structure. Because of their relatively small size, intact chemokines can be studied effectively by NMR spectroscopy to examine their structures in solution. In addition, NMR relaxation experiments of intact chemokines can provide detailed information about the intrinsic dynamic behavior; such analyses have helped for example to understand the activity of TC-1, an antimicrobial variant of CXCL7/NAP-2. With chemokine dimerization and oligomerization influencing their functional properties, the use of NMR diffusion experiments can provide information about monomer-dimer equilibria in solution. Furthermore, NMR chemical shift perturbation experiments can be used to map out the interface between self-associating subunits. Moreover, the unusual case of XCL1/lymphotactin presents a chemokine that can interconvert between two distinct folds in solution, both of which have been elucidated. Finally, recent advances have allowed for the determination of the structures of chemokines in complex with glycosaminoglycans, a process that could interfere with their antimicrobial activity. Taken together, these studies highlight several different structural facets that contribute to the way in which chemokines exert their direct microbicidal actions.
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Affiliation(s)
- Leonard T Nguyen
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary Calgary, AB, Canada
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41
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Murphy EC, Frick IM. Gram-positive anaerobic cocci--commensals and opportunistic pathogens. FEMS Microbiol Rev 2012; 37:520-53. [PMID: 23030831 DOI: 10.1111/1574-6976.12005] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 07/30/2012] [Accepted: 09/24/2012] [Indexed: 12/30/2022] Open
Abstract
Among the Gram-positive anaerobic bacteria associated with clinical infections, the Gram-positive anaerobic cocci (GPAC) are the most prominent and account for approximately 25-30% of all isolated anaerobic bacteria from clinical specimens. Still, routine culture and identification of these slowly growing anaerobes to the species level has been limited in the diagnostic laboratory, mainly due to the requirement of prolonged incubation times and time-consuming phenotypic identification. In addition, GPAC are mostly isolated from polymicrobial infections with known pathogens and therefore their relevance has often been overlooked. However, through improvements in diagnostic and in particular molecular techniques, the isolation and identification of individual genera and species of GPAC associated with specific infections have been enhanced. Furthermore, the taxonomy of GPAC has undergone considerable changes over the years, mainly due to the development of molecular identification methods. Existing species have been renamed and novel species have been added, resulting in changes of the nomenclature. As the abundance and significance of GPAC in clinical infections grow, knowledge of virulence factors and antibiotic resistance patterns of different species becomes more important. The present review describes recent advances of GPAC and what is known of the biology and pathogenic effects of Anaerococcus, Finegoldia, Parvimonas, Peptoniphilus and Peptostreptococcus, the most important GPAC genera isolated from human infections.
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Affiliation(s)
- Elizabeth Carmel Murphy
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
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42
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Abstract
Chemokines are best known for their classic leukocyte chemotactic activity, which is critical for directing the immune response to sites of infection and injury. However, recent studies have suggested that at least some chemokines may also interfere with infectious agents directly. Antimicrobial chemokines tend to contain amphipathic alpha helical secondary structure, and broad-spectrum activity against both Gram-positive and Gram negative bacteria, as well as fungi. Conversely, several bacteria have been identified that possess mechanisms for specifically blocking the antimicrobial activities of chemokines. Although the precise mechanisms by which chemokines and microbes disarm one another in vitro remain unknown, there is now emerging evidence in vivo that such interactions may be biologically significant. More research will be needed to determine whether chemokines with direct antimicrobial activity may be translated into a novel class of antibiotics.
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Affiliation(s)
- Sunny C. Yung
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
| | - Philip M. Murphy
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesda, MD, USA
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43
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Eliasson M, Olin AI, Malmström JA, Mörgelin M, Bodelsson M, Collin M, Egesten A. Characterization of released polypeptides during an interferon-γ-dependent antibacterial response in airway epithelial cells. J Interferon Cytokine Res 2012; 32:524-33. [PMID: 22909116 DOI: 10.1089/jir.2012.0017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
When pathogenic bacteria breach the epithelial lining at mucosal surfaces, rapidly available innate immune mechanisms are critical to halt the infection. In the present study, we characterized the production of antibacterial polypeptides released by epithelial cells. IFN-γ, but neither TNF nor IL-1β alone, induced release of antibacterial activity to a cell culture medium, causing a lytic appearance of killed bacteria as revealed by electron microscopy. Addition of the protein streptococcal inhibitor of complement, derived from Streptococcus pyogenes, known for its ability to neutralize antimicrobial polypeptides (AMPs), reduced the antibacterial activity of the medium. Characterization of the antibacterial incubation medium using mass spectrometric approaches and ELISAs, displayed presence of several classical AMPs, antibacterial chemokines, as well as complement factors and proteases that may interfere with bacterial killing. Many were constitutively produced, that is, being released by cells incubated in a medium alone. While a combination of IFN-γ and TNF did not increase bacterial killing, the presence of TNF boosted the amounts and detectable number of AMPs, including antibacterial chemokines. However, the methods applied in the study failed to single out certain AMPs as critical mediators, but rather demonstrate the broad range of molecules involved. Since many AMPs are highly amphiphatic in nature (i.e., cationic and hydrophobic), it is possible that difficulties in optimizing recovery present limitations in the context investigated. The findings demonstrate that epithelial cells have a constitutive production of AMPs and that IFN-γ is an important inducer of an antibacterial response in which is likely to be a critical part of the innate host defense against pathogenic bacteria at mucosal surfaces.
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Affiliation(s)
- Mette Eliasson
- Section for Respiratory Medicine & Allergology, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Sweden
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44
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Wolf M, Moser B. Antimicrobial activities of chemokines: not just a side-effect? Front Immunol 2012; 3:213. [PMID: 22837760 PMCID: PMC3401835 DOI: 10.3389/fimmu.2012.00213] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/03/2012] [Indexed: 11/22/2022] Open
Abstract
The large family of chemoattractant cytokines (chemokines) embraces multiple, in part unrelated functions that go well beyond chemotaxis. Undoubtedly, the control of immune cell migration (chemotaxis) is the single, unifying response mediated by all chemokines, which involves the sequential engagement of chemokine receptors on migrating target cells. However, numerous additional cellular responses are mediated by some (but not all) chemokines, including angiogenesis, tumor cell growth, T-cell co-stimulation, and control of HIV-1 infection. The recently described antimicrobial activity of several chemokines is of particular interest because antimicrobial peptides are thought to provide an essential first-line defense against invading microbes at the extremely large body surfaces of the skin, lungs, and gastrointestinal-urinary tract. Here we summarize the current knowledge about chemokines with antimicrobial activity and discuss their potential contribution to the control of bacterial infections that may take place at the earliest stage of antimicrobial immunity. In the case of homeostatic chemokines with antimicrobial function, such as CXCL14, we propose an immune surveillance function in healthy epithelial tissues characterized by low-level exposure to environmental microbes. Inflammatory chemokines, i.e., chemokines that are produced in tissue cells in response to microbial antigens (such as pathogen-associated molecular patterns) may be more important in orchestrating the cellular arm in antimicrobial immunity.
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Affiliation(s)
- Marlene Wolf
- Theodor Kocher Institute, University of BernBern, Switzerland
| | - Bernhard Moser
- Institute of Infection and Immunity, School of Medicine, Cardiff UniversityCardiff, UK
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45
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Molecular Biologic Assessment of Cutaneous Specimens of Ocular Rosacea. Ophthalmic Plast Reconstr Surg 2012; 28:246-50. [DOI: 10.1097/iop.0b013e31824dd9d4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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46
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Sonesson A, Kasetty G, Olin AI, Malmsten M, Mörgelin M, Sørensen OE, Schmidtchen A. Thymic stromal lymphopoietin exerts antimicrobial activities. Exp Dermatol 2012; 20:1004-10. [PMID: 22092577 DOI: 10.1111/j.1600-0625.2011.01391.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Thymic stromal lymphopoietin (TSLP) is an interleukin-7-like cytokine expressed by epithelial cells and reported to be involved in allergic diseases and atopic eczema. The presence of several predicted α-helical regions in TSPL, a structure characterizing many classical antimicrobial peptides (AMPs), prompted us to investigate whether TSLP exerts antimicrobial activities. Recombinant human TSLP exerted antimicrobial activity, particularly against Gram-negative bacteria. Using synthetic overlapping peptide 20-mers of TSLP, it was demonstrated that the antimicrobial effect is primarily mediated by the C-terminal region of the protein. MKK34 (MKKRRKRKVTTNKCLEQVSQLQGLWRRFNRPLLK), a peptide spanning a C-terminal α-helical region in TSLP, showed potent antimicrobial activities, in physiological salt conditions and in the presence of human plasma. Fluorescent studies of peptide-treated bacteria, electron microscopy and liposome leakage models showed that MKK34 exerted membrane-disrupting effects comparable to those of the classical AMP LL-37. Moreover, TSLP was degraded into multiple fragments by staphylococcal V8 proteinase. One major antimicrobial degradation fragment was found to encompass the C-terminal antimicrobial region defined by the MKK34 peptide. We here describe a novel antimicrobial role for TSLP. The antimicrobial activity is primarily mediated by the C-terminal part of the protein. In combination with the previously known cytokine function of TSLP, our result indicates dual functions of the molecule and a previously unknown role in host defense.
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Affiliation(s)
- Andreas Sonesson
- Divisions of Dermatology and Venereology Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden.
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47
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Yount NY, Yeaman MR. Emerging themes and therapeutic prospects for anti-infective peptides. Annu Rev Pharmacol Toxicol 2012; 52:337-60. [PMID: 22235859 DOI: 10.1146/annurev-pharmtox-010611-134535] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pathogens resistant to most conventional anti-infectives are a harbinger of the need to discover and develop novel anti-infective agents and strategies. Endogenous host defense peptides (HDPs) have retained evolution-tested efficacy against pathogens that have become refractory to traditional antibiotics. Evidence indicates that HDPs target membrane integrity, bioenergetics, and other essential features of microbes that may be less mutable than conventional antibiotic targets. For these reasons, HDPs have received increasing attention as templates for development of potential anti-infective therapeutics. Unfortunately, advances toward this goal have proven disappointing, in part owing to limited understanding of relevant structure-activity and selective toxicity relationships in vivo, a limited number of reports and overall understanding of HDP pharmacology, and the difficulty of cost-effective production of such peptides on a commodity scale. However, recent molecular insights and technology innovations have led to novel HDP-based and mimetic anti-infective peptide candidates designed to overcome these limitations. Although initial setbacks have presented challenges to therapeutic development, emerging themes continue to highlight the potential of HDP-based anti-infectives as a platform for next-generation therapeutics that will help address the growing threat of multidrug-resistant infections.
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Affiliation(s)
- Nannette Y Yount
- Divisions of Infectious Diseases and Molecular Medicine, Los Angeles County Harbor-UCLA Medical Center, Torrance, California 90509, USA
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48
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Frick IM, Nordin SL, Baumgarten M, Mörgelin M, Sørensen OE, Olin AI, Egesten A. Constitutive and inflammation-dependent antimicrobial peptides produced by epithelium are differentially processed and inactivated by the commensal Finegoldia magna and the pathogen Streptococcus pyogenes. THE JOURNAL OF IMMUNOLOGY 2011; 187:4300-9. [PMID: 21918193 DOI: 10.4049/jimmunol.1004179] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Epithelial linings serve as physical barriers and produce antimicrobial peptides (AMPs) to maintain host integrity. Examples are the bactericidal proteins midkine (MK) and BRAK/CXCL14 that are constitutively produced in the skin epidermal layer, where the anaerobic Gram-positive coccoid commensal Finegoldia magna resides. Consequently, this bacterium is likely to encounter both MK and BRAK/CXCL14, making these molecules possible threats to its habitat. In this study, we show that MK expression is upregulated during inflammation, concomitant with a strong downregulation of BRAK/CXCL14, resulting in changed antibacterial conditions. MK, BRAK/CXCL14, and the inflammation-dependent antimicrobial β-defensins human β-defensin (hBD)-2 and hBD-3 all showed bactericidal activity against both F. magna and the virulent pathogen Streptococcus pyogenes at similar concentrations. SufA, a released protease of F. magna, degraded MK and BRAK/CXCL14 but not hBD-2 nor hBD-3. Cleavage was seen at lysine and arginine residues, amino acids characteristic of AMPs. Intermediate SufA-degraded fragments of MK and BRAK/CXCL14 showed stronger bactericidal activity against S. pyogenes than F. magna, thus promoting survival of the latter. In contrast, the cysteine-protease SpeB of S. pyogenes rapidly degraded all AMPs investigated. The proteins FAF and SIC, released by F. magna and S. pyogenes, respectively, neutralized the antibacterial activity of MK and BRAK/CXCL14, protein FAF being the most efficient. Quantitation and colocalization by immunoelectron microscopy demonstrated significant levels and interactions of the molecules in in vivo and ex vivo samples. The findings reflect strategies used by a permanently residing commensal and a virulent pathogen, the latter operating during the limited time course of invasive disease.
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Affiliation(s)
- Inga-Maria Frick
- Section for Infection Medicine, Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-221 85 Lund, Sweden
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49
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Rahnamaeian M. Antimicrobial peptides: modes of mechanism, modulation of defense responses. PLANT SIGNALING & BEHAVIOR 2011; 6:1325-32. [PMID: 21847025 PMCID: PMC3258061 DOI: 10.4161/psb.6.9.16319] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 05/21/2011] [Accepted: 05/23/2011] [Indexed: 05/20/2023]
Abstract
Complicated schemes of classical breeding and their drawbacks, environmental risks imposed by agrochemicals, decrease of arable land, and coincident escalating damages of pests and pathogens have accentuated the necessity for highly efficient measures to improve crop protection. During co-evolution of host-microbe interactions, antimicrobial peptides (AMPs) have exhibited a brilliant history in protecting host organisms against devastation by invading pathogens. Since the 1980s, a plethora of AMPs has been isolated from and characterized in different organisms. Nevertheless the AMPs expressed in plants render them more resistant to diverse pathogens, a more orchestrated approach based on knowledge of their mechanisms of action and cellular targets, structural toxic principle, and possible impact on immune system of corresponding transgenic plants will considerably improve crop protection strategies against harmful plant diseases. This review outlines the current knowledge on different modes of action of AMPs and then argues the waves of AMPs’ ectopic expression on transgenic plants’ immune system.
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Affiliation(s)
- Mohammad Rahnamaeian
- Department of Plant Biotechnology, College of Agriculture, Shahid Bahonar University, Kerman, Iran.
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Kotzsch A, Vernet E, Hammarström M, Berthelsen J, Weigelt J, Gräslund S, Sundström M. A secretory system for bacterial production of high-profile protein targets. Protein Sci 2011; 20:597-609. [PMID: 21308845 DOI: 10.1002/pro.593] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Escherichia coli represents a robust, inexpensive expression host for the production of recombinant proteins. However, one major limitation is that certain protein classes do not express well in a biologically relevant form using standard expression approaches in the cytoplasm of E. coli. To improve the usefulness of the E. coli expression platform we have investigated combinations of promoters and selected N-terminal fusion tags for the extracellular expression of human target proteins. A comparative study was conducted on 24 target proteins fused to outer membrane protein A (OmpA), outer membrane protein F (OmpF) and osmotically inducible protein Y (OsmY). Based on the results of this initial study, we carried out an extended expression screen employing the OsmY fusion and multiple constructs of a more diverse set of human proteins. Using this high-throughput compatible system, we clearly demonstrate that secreted biomedically relevant human proteins can be efficiently retrieved and purified from the growth medium.
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Affiliation(s)
- Alexander Kotzsch
- Facility for Protein Science and Technology, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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