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Zhang J, Wieser A, Lin H, Li H, Hu M, Behrens IK, Schiergens TS, Gerbes AL, Steib CJ. Kupffer cell activation by different microbial lysates: Toll-like receptor-2 plays pivotal role on thromboxane A 2 production in mice and humans. Eur J Immunol 2020; 50:1988-1997. [PMID: 32618365 DOI: 10.1002/eji.201948507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 05/29/2020] [Accepted: 06/30/2020] [Indexed: 11/11/2022]
Abstract
Thromboxane (TX) A2 has been identified as an important intrahepatic vasoconstrictor upon Kupffer cell (KC) activation during infections such as spontaneous bacterial peritonitis (SBP). The study aimed to investigate the role of TLRs in the TXA2 increase in liver nonparenchymal cells and their related mechanisms. Here, we identified TLR-2 as a common pathway for different microbials: microbial lysates including Gram-positive bacteria, Gram-negative bacteria, and fungi all increased TXA2 secretion via activation of TLR-2 in human KCs, accompanied by increased expression and phosphorylation of Myd88-related pathway. Of all TLR agonists, only TLR-1, -2, and -4 agonists increased TXA2 in human KCs. These results were further confirmed by mouse liver nonparenchymal cells. Comparing the effects of TLR-1, -2, and -4 antagonists, only TLR-2 antagonist showed inhibitory effects with all tested microbial lysates. Pretreatment with TLR-2 antagonist in human KCs blocked the secretion of IL-10, CXCL-10, TNF-α, and IL-6 induced by Gram-positive and Gram-negative bacterial stimulation. IL-23 and IL-1β were only induced by Gram-negative bacteria. Thus, TLR-2 might be a potential marker and an attractive target for future treatment of patients with SBP. In addition, IL-23 and IL-1β might distinguish early between Gram-positive and Gram-negative SBP.
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Affiliation(s)
- Jiang Zhang
- Department of Medicine II, University Hospital, Liver Centre Munich, LMU Munich, Munich, Germany
| | - Andreas Wieser
- Faculty of Medicine, Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, LMU Munich, Munich, Germany.,Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich, Munich, Germany.,German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | - Hao Lin
- Department of Medicine II, University Hospital, Liver Centre Munich, LMU Munich, Munich, Germany
| | - Hanwei Li
- Department of Medicine II, University Hospital, Liver Centre Munich, LMU Munich, Munich, Germany
| | - Moyan Hu
- Chair for Fish Diseases and Fisheries Biology, Faculty of Veterinary Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Ina-Kristin Behrens
- Faculty of Medicine, Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, LMU Munich, Munich, Germany
| | - Tobias S Schiergens
- Department of General, Visceral, and Transplant Surgery, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Alexander L Gerbes
- Department of Medicine II, University Hospital, Liver Centre Munich, LMU Munich, Munich, Germany
| | - Christian J Steib
- Department of Medicine II, University Hospital, Liver Centre Munich, LMU Munich, Munich, Germany
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Abstract
Interaction of Streptococcus pneumoniae with the surface of endothelial cells is mediated in blood flow via mechanosensitive proteins such as the Von Willebrand Factor (VWF). This glycoprotein changes its molecular conformation in response to shear stress, thereby exposing binding sites for a broad spectrum of host-ligand interactions. In general, culturing of primary endothelial cells under a defined shear flow is known to promote the specific cellular differentiation and the formation of a stable and tightly linked endothelial layer resembling the physiology of the inner lining of a blood vessel. Thus, the functional analysis of interactions between bacterial pathogens and the host vasculature involving mechanosensitive proteins requires the establishment of pump systems that can simulate the physiological flow forces known to affect the surface of vascular cells. The microfluidic device used in this study enables a continuous and pulseless recirculation of fluids with a defined flow rate. The computer-controlled air-pressure pump system applies a defined shear stress on endothelial cell surfaces by generating a continuous, unidirectional, and controlled medium flow. Morphological changes of the cells and bacterial attachment can be microscopically monitored and quantified in the flow by using special channel slides that are designed for microscopic visualization. In contrast to static cell culture infection, which in general requires a sample fixation prior to immune labeling and microscopic analyses, the microfluidic slides enable both the fluorescence-based detection of proteins, bacteria, and cellular components after sample fixation; serial immunofluorescence staining; and direct fluorescence-based detection in real time. In combination with fluorescent bacteria and specific fluorescence-labeled antibodies, this infection procedure provides an efficient multiple component visualization system for a huge spectrum of scientific applications related to vascular processes.
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Affiliation(s)
- Hilger Jagau
- Institut für Mikrobiologie, Technische Universität Braunschweig; Devision of Infection Medicine, Department of Clinical Science, Lund University
| | - Ina-Kristin Behrens
- Institut für Mikrobiologie, Technische Universität Braunschweig; Medical Microbiology and Hospital Epidemiology, Max von Pettenkofer Institute, Ludwig Maximilians University
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig; Department of Molecular Infection Biology, Helmholtz Center for Infection Research
| | - Simone Bergmann
- Institut für Mikrobiologie, Technische Universität Braunschweig;
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Jagau H, Behrens IK, Lahme K, Lorz G, Köster RW, Schneppenheim R, Obser T, Brehm MA, König G, Kohler TP, Rohde M, Frank R, Tegge W, Fulde M, Hammerschmidt S, Steinert M, Bergmann S. Von Willebrand Factor Mediates Pneumococcal Aggregation and Adhesion in Blood Flow. Front Microbiol 2019; 10:511. [PMID: 30972039 PMCID: PMC6443961 DOI: 10.3389/fmicb.2019.00511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/27/2019] [Indexed: 12/24/2022] Open
Abstract
Streptococcus pneumoniae is a major cause of community acquired pneumonia and septicaemia in humans. These diseases are frequently associated with thromboembolic cardiovascular complications. Pneumococci induce the exocytosis of endothelial Weibel-Palade Bodies and thereby actively stimulate the release of von Willebrand factor (VWF), which is an essential glycoprotein of the vascular hemostasis. Both, the pneumococcus induced pulmonary inflammation and the thromboembolytic complications are characterized by a dysbalanced hemostasis including a marked increase in VWF plasma concentrations. Here, we describe for the first time VWF as a novel interaction partner of capsulated and non-encapsulated pneumococci. Moreover, cell culture infection analyses with primary endothelial cells characterized VWF as bridging molecule that mediates bacterial adherence to endothelial cells in a heparin-sensitive manner. Due to the mechanoresponsive changes of the VWF protein conformation and multimerization status, which occur in the blood stream, we used a microfluidic pump system to generate shear flow-induced multimeric VWF strings on endothelial cell surfaces and analyzed attachment of RFP-expressing pneumococci in flow. By applying immunofluorescence visualization and additional electron microscopy, we detected a frequent and enduring bacterial attachment to the VWF strings. Bacterial attachment to the endothelium was confirmed in vivo using a zebrafish infection model, which is described in many reports and acknowledged as suitable model to study hemostasis mechanisms and protein interactions of coagulation factors. Notably, we visualized the recruitment of zebrafish-derived VWF to the surface of pneumococci circulating in the blood stream and detected a VWF-dependent formation of bacterial aggregates within the vasculature of infected zebrafish larvae. Furthermore, we identified the surface-exposed bacterial enolase as pneumococcal VWF binding protein, which interacts with the VWF domain A1 and determined the binding kinetics by surface plasmon resonance. Subsequent epitope mapping using an enolase peptide array indicates that the peptide 181YGAEIFHALKKILKS195 might serve as a possible core sequence of the VWF interaction site. In conclusion, we describe a VWF-mediated mechanism for pneumococcal anchoring within the bloodstream via surface-displayed enolase, which promotes intravascular bacterial aggregation.
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Affiliation(s)
- Hilger Jagau
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Ina-Kristin Behrens
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Karen Lahme
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Georgina Lorz
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard W Köster
- Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard Schneppenheim
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf (UKE Hamburg), Hamburg, Germany
| | - Tobias Obser
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf (UKE Hamburg), Hamburg, Germany
| | - Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf (UKE Hamburg), Hamburg, Germany
| | - Gesa König
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf (UKE Hamburg), Hamburg, Germany
| | - Thomas P Kohler
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Universität Greifswald, Greifswald, Germany
| | - Manfred Rohde
- Helmholtz Centre for Infection Research, Central Facility for Microscopy, Braunschweig, Germany
| | - Ronald Frank
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Werner Tegge
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marcus Fulde
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Universität Greifswald, Greifswald, Germany
| | - Michael Steinert
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany.,Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Simone Bergmann
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
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