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Chen W, Zhao S, Ita M, Li Y, Ji J, Jiang Y, Redmond HP, Wang JH, Liu J. An Early Neutrophil Recruitment into the Infectious Site Is Critical for Bacterial Lipoprotein Tolerance-Afforded Protection against Microbial Sepsis. THE JOURNAL OF IMMUNOLOGY 2019; 204:408-417. [PMID: 31801813 DOI: 10.4049/jimmunol.1801602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 11/04/2019] [Indexed: 12/12/2022]
Abstract
Bacterial lipoprotein (BLP)-induced tolerance represents an essential regulatory mechanism during bacterial infection and has been shown to protect against microbial sepsis. This protection is generally attributed to BLP-tolerized monocytes/macrophages characterized by hyporesponsiveness in producing inflammatory cytokines and, simultaneously, an augmented antimicrobial activity. However, the contribution of polymorphonuclear neutrophils (PMNs), another major player in innate immunity against bacterial infection, to BLP tolerance-afforded protection against microbial sepsis has not been identified. In this study, we report that induction of BLP tolerance protected mice against cecal ligation and puncture-induced polymicrobial sepsis, with significantly improved survival. Importantly, BLP tolerization via i.p. injection triggered an early PMN recruitment even before bacterial infection and promoted further PMN influx into the infectious site (i.e., the peritoneal cavity upon cecal ligation and puncture-associated septic challenge). Notably, this early PMN influx was mediated by BLP tolerization-induced PMN chemoattractant CXCL2-formed concentration gradient between the circulation and peritoneal cavity. Critically, blockage of PMN influx with the CXCR2 antagonist SB225002 abolished BLP tolerance-afforded protection and rendered BLP-tolerized mice more vulnerable to microbial infection with impaired bacterial clearance and increased overall mortality. Thus, our results highlight that an early recruitment of PMNs in the infectious site, as an important cellular mechanism, contributes to BLP tolerance-afforded protection against microbial sepsis.
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Affiliation(s)
- Wenting Chen
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.,Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; and
| | - Shuqi Zhao
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Michael Ita
- Department of Academic Surgery, Cork University Hospital, University College Cork, Wilton, Cork, Ireland
| | - Yue Li
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Jingjing Ji
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yong Jiang
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - H Paul Redmond
- Department of Academic Surgery, Cork University Hospital, University College Cork, Wilton, Cork, Ireland
| | - Jiang Huai Wang
- Department of Academic Surgery, Cork University Hospital, University College Cork, Wilton, Cork, Ireland
| | - Jinghua Liu
- Guangdong Provincial Key Laboratory of Proteomics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China;
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Distinct pattern of immune tolerance in dendritic cells treated with lipopolysaccharide or lipoteichoic acid. Mol Immunol 2017; 91:57-64. [DOI: 10.1016/j.molimm.2017.08.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 08/20/2017] [Accepted: 08/23/2017] [Indexed: 11/17/2022]
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Huang Z, Yi X, Chen Y, Hou X, Wang X, Zhu P, Zhao K, Wu S, Fu N, Liu B. Pretreatment of Pam3CSK4 attenuates inflammatory responses caused by systemic infection of methicillin-resistant Staphylococcus aureus in mice. Biomed Pharmacother 2017; 95:1684-1692. [PMID: 28954388 DOI: 10.1016/j.biopha.2017.09.058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 09/10/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022] Open
Abstract
Pam3CSK4 is a synthetic tripalmitoylated lipopeptide that acts as a ligand of TLR1/TLR2 by mimicking the acetylated amino terminus of bacterial lipoproteins. Here we found that pretreatment of Pam3CSK4 protected mice from systemic infection of methicillin-resistant Staphylococcus aureus (MRSA), and enhanced the bacterial clearance in bacteremia model. Pro-inflammatory cytokines, such as TNF-α, IL-6, MCP-1 and IFN-γ were significantly decreased in serum from Pam3CSK4-treated mice. Besides, upon PamCSK4 treatment, the TLR2 expression was down-regulated, IRAK1 phosphorylation was inhibited, and the expression of IRAK-M and Tollip, two negative regulators of NF-κB pathway, was up-regulated. All of these indicated that Pam3CSK4 attenuated inflammation via inhibiting TLR1/TLR2 and the downstream NF-κB pathways, and suggested that Pam3CSK4 could be a potential immune modulator for MRSA systemic infection.
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Affiliation(s)
- Zhaoxia Huang
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Xiayu Yi
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Yiguo Chen
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Xiaorui Hou
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Xiangyu Wang
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Ping Zhu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Kangmin Zhao
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Shuangshuang Wu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Ning Fu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China
| | - Beiyi Liu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, PR China.
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THP-1-derived macrophages render lung epithelial cells hypo-responsive to Legionella pneumophila - a systems biology study. Sci Rep 2017; 7:11988. [PMID: 28931863 PMCID: PMC5607273 DOI: 10.1038/s41598-017-12154-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 09/04/2017] [Indexed: 11/25/2022] Open
Abstract
Immune response in the lung has to protect the huge alveolar surface against pathogens while securing the delicate lung structure. Macrophages and alveolar epithelial cells constitute the first line of defense and together orchestrate the initial steps of host defense. In this study, we analysed the influence of macrophages on type II alveolar epithelial cells during Legionella pneumophila-infection by a systems biology approach combining experimental work and mathematical modelling. We found that L. pneumophila-infected THP-1-derived macrophages provoke a pro-inflammatory activation of neighboring lung epithelial cells, but in addition render them hypo-responsive to direct infection with the same pathogen. We generated a kinetic mathematical model of macrophage activation and identified a paracrine mechanism of macrophage-secreted IL-1β inducing a prolonged IRAK-1 degradation in lung epithelial cells. This intercellular crosstalk may help to avoid an overwhelming inflammatory response by preventing excessive local secretion of pro-inflammatory cytokines and thereby negatively regulating the recruitment of immune cells to the site of infection. This suggests an important but ambivalent immunomodulatory role of macrophages in lung infection.
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Shen XF, Cao K, Jiang JP, Guan WX, Du JF. Neutrophil dysregulation during sepsis: an overview and update. J Cell Mol Med 2017; 21:1687-1697. [PMID: 28244690 PMCID: PMC5571534 DOI: 10.1111/jcmm.13112] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 01/05/2017] [Indexed: 12/15/2022] Open
Abstract
Sepsis remains a leading cause of death worldwide, despite advances in critical care, and understanding of the pathophysiology and treatment strategies. No specific therapy or drugs are available for sepsis. Neutrophils play a critical role in controlling infection under normal conditions, and it is suggested that their migration and antimicrobial activity are impaired during sepsis which contribute to the dysregulation of immune responses. Recent studies further demonstrated that interruption or reversal of the impaired migration and antimicrobial function of neutrophils improves the outcome of sepsis in animal models. In this review, we provide an overview of the associated mediators and signal pathways involved which govern the survival, migration and antimicrobial function of neutrophils in sepsis, and discuss the potential of neutrophils as a target to specifically diagnose and/or predict the outcome of sepsis.
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Affiliation(s)
- Xiao-Fei Shen
- Department of General Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Ke Cao
- Department of Intensive Care Unit, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jin-Peng Jiang
- Department of Rehabilitation Medicine, PLA Army General Hospital, Beijing, China
| | - Wen-Xian Guan
- Department of General Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jun-Feng Du
- Department of General Surgery, PLA Army General Hospital, Beijing, China
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Liu J, Xiang J, Li X, Blankson S, Zhao S, Cai J, Jiang Y, Redmond HP, Wang JH. NF-κB activation is critical for bacterial lipoprotein tolerance-enhanced bactericidal activity in macrophages during microbial infection. Sci Rep 2017; 7:40418. [PMID: 28079153 PMCID: PMC5227741 DOI: 10.1038/srep40418] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/07/2016] [Indexed: 12/13/2022] Open
Abstract
Tolerance to bacterial components represents an essential regulatory mechanism during bacterial infection. Bacterial lipoprotein (BLP)-induced tolerance confers protection against microbial sepsis by attenuating inflammatory responses and augmenting antimicrobial activity in innate phagocytes. It has been well-documented that BLP tolerance-attenuated proinflammatory cytokine production is associated with suppressed TLR2 signalling pathway; however, the underlying mechanism(s) involved in BLP tolerance-enhanced antimicrobial activity is unclear. Here we report that BLP-tolerised macrophages exhibited accelerated phagosome maturation and enhanced bactericidal activity upon bacterial infection, with upregulated expression of membrane-trafficking regulators and lysosomal enzymes. Notably, bacterial challenge resulted in a strong activation of NF-κB pathway in BLP-tolerised macrophages. Importantly, activation of NF-κB pathway is critical for BLP tolerance-enhanced antimicrobial activity, as deactivation of NF-κB in BLP-tolerised macrophages impaired phagosome maturation and intracellular killing of the ingested bacteria. Finally, activation of NF-κB pathway in BLP-tolerised macrophages was dependent on NOD1 and NOD2 signalling, as knocking-down NOD1 and NOD2 substantially inhibited bacteria-induced activation of NF-κB and overexpression of Rab10 and Acp5, two membrane-trafficking regulators and lysosomal enzymes contributed to BLP tolerance-enhanced bactericidal activity. These results indicate that activation of NF-κB pathway is essential for BLP tolerance-augmented antimicrobial activity in innate phagocytes and depends primarily on both NOD1 and NOD2.
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Affiliation(s)
- Jinghua Liu
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - Jing Xiang
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - Xue Li
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - Siobhan Blankson
- Department of Academic Surgery, University College Cork/National University of Ireland, Cork University Hospital, Cork, Ireland
| | - Shuqi Zhao
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - Junwei Cai
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - Yong Jiang
- Key Laboratory of Functional Proteomics of Guangdong Province, Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China
| | - H Paul Redmond
- Department of Academic Surgery, University College Cork/National University of Ireland, Cork University Hospital, Cork, Ireland
| | - Jiang Huai Wang
- Department of Academic Surgery, University College Cork/National University of Ireland, Cork University Hospital, Cork, Ireland
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