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Pleskova SN, Bezrukov NA, Bobyk SZ, Gorshkova EN, Novikov DV. Pathogenic Escherichia coli change the adhesion between neutrophils and endotheliocytes in the experimental bacteremia model. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:254-264. [PMID: 39045084 PMCID: PMC11263930 DOI: 10.15698/mic2024.07.830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 06/13/2024] [Accepted: 07/03/2024] [Indexed: 07/25/2024]
Abstract
Septicemia caused by gram-negative bacteria is characterized by high death rate due to the endotoxin release. Since the septicemia depends not only on biochemical aspects of interactions in the system bloodstream, the study of mechanical interactions is also important. Using a model of experimental septicemia caused by E. coli, a hyperproduction of integrins CD11a and CD11b by neutrophils was shown, but this did not lead to the establishment of strong adhesion contacts between endothelial cells and neutrophils. On the contrary, adhesion force and work, as assessed by FS spectroscopy, were statistically significantly reduced in the presence of bacteria. It has also been shown that exposure to the pathogenic strain E. coli 321 increases the stiffness of the membrane-cytoskeleton complex of endothelial cells and bacteria significantly change their morphology on long-term observation. At the same time, we observed the death of neutrophils by apoptosis. Thus, it was shown that besides lipopolysaccharide release there are other pathogenic factors of E. coli: decrease in the interaction between neutrophil and endothelial cell caused by an increase of the endothelial cell rigidity and apoptotic death of neutrophils probably as a result of adhesins and exotoxin effects. Obtained results should be taken in mind during the therapy of septicemia.
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Affiliation(s)
- Svetlana N Pleskova
- Research Laboratory of Scanning Probe Microscopy, Lobachevsky State University of Nizhny NovgorodNizhny NovgorodRussia
- "Nanotechnology and Biotechnology" Department, Nizhny Novgorod State Technical University named after Alekseev R.E.Nizhny NovgorodRussia
| | - Nikolay A Bezrukov
- Research Laboratory of Scanning Probe Microscopy, Lobachevsky State University of Nizhny NovgorodNizhny NovgorodRussia
| | - Sergey Z Bobyk
- Research Laboratory of Scanning Probe Microscopy, Lobachevsky State University of Nizhny NovgorodNizhny NovgorodRussia
| | - Ekaterina N Gorshkova
- Research Laboratory of Scanning Probe Microscopy, Lobachevsky State University of Nizhny NovgorodNizhny NovgorodRussia
| | - Dmitri V Novikov
- Nizhny Novgorod Research Institute of Epidemiology and microbiology named after Blokhina I.N.Nizhny NovgorodRussia
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Lu J, Ding J, Chu B, Ji C, Zhang Q, Xu Y, Song B, Wang H, He Y. Inactive Trojan Bacteria as Safe Drug Delivery Vehicles Crossing the Blood-Brain Barrier. NANO LETTERS 2023; 23:4326-4333. [PMID: 37130058 DOI: 10.1021/acs.nanolett.3c00563] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Escherichia coli K1 (EC-K1) can bypass the blood-brain barrier (BBB) and cause meningitis. Excitingly, we find the "dead EC-K1" can safely penetrate the BBB because they retain the intact structure and chemotaxis of the live EC-K1, while losing their pathogenicity. Based on this, we develop a safe "dead EC-K1"-based drug delivery system, in which EC-K1 engulf the maltodextrin (MD)-modified therapeutics through the bacteria-specific MD transporter pathway, followed by the inactivation via UV irradiation. We demonstrate that the dead bacteria could carry therapeutics (e.g., indocyanine green (ICG)) and together bypass the BBB after intravenous injection into the mice, delivering ∼3.0-fold higher doses into the brain than free ICG under the same conditions. What is more, all mice remain healthy even after 14 days of intravenous injection of ∼109 CFU of inactive bacteria. As a proof of concept, we demonstrate the developed strategy enables the therapy of bacterial meningitis and glioblastoma in mice.
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Affiliation(s)
- Jianping Lu
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Jiali Ding
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Binbin Chu
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Chen Ji
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Qian Zhang
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Yanan Xu
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Bin Song
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Houyu Wang
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
| | - Yao He
- Suzhou Key Laboratory of Nanotechnology and Biomedicine, Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology (NANO-CIC), Soochow University, Suzhou 215123, China
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3
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YbdO Promotes the Pathogenicity of Escherichia coli K1 by Regulating Capsule Synthesis. Int J Mol Sci 2022; 23:ijms23105543. [PMID: 35628353 PMCID: PMC9141747 DOI: 10.3390/ijms23105543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/12/2022] [Accepted: 05/15/2022] [Indexed: 11/17/2022] Open
Abstract
Escherichia coli K1 is the most popular neonatal meningitis-causing Gram-negative bacterium. As a key virulence determinant, the K1 capsule enhances the survival of E. coli K1 in human brain microvascular endothelial cells (HBMECs) upon crossing the blood–brain barrier; however, the regulatory mechanisms of capsule synthesis during E. coli K1 invasion of HBMECs remain unclear. Here, we identified YbdO as a transcriptional regulator that promotes E. coli K1 invasion of HBMECs by directly activating K1 capsule gene expression to increase K1 capsule synthesis. We found that ybdO deletion significantly reduced HBMEC invasion by E. coli K1 and meningitis occurrence in mice. Additionally, electrophoretic mobility shift assay and chromatin immunoprecipitation–quantitative polymerase chain reaction analysis indicated that YbdO directly activates kpsMT and neuDBACES expression, which encode products involved in K1 capsule transport and synthesis by directly binding to the kpsM promoter. Furthermore, ybdO transcription was directly repressed by histone-like nucleoid structuring protein (H-NS), and we observed that acidic pH similar to that of early and late endosomes relieves this transcriptional repression. These findings demonstrated the regulatory mechanism of YbdO on K1 capsule synthesis, providing further insights into the evolution of E. coli K1 pathogenesis and host–pathogen interaction.
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Natarajan S, Govender K, Shobo A, Baijnath S, Arvidsson PI, Govender T, Lin J, Maguire GE, Naicker T, Kruger HG. Potential of brain mast cells for therapeutic application in the immune response to bacterial and viral infections. Brain Res 2021; 1767:147524. [PMID: 34015358 DOI: 10.1016/j.brainres.2021.147524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/21/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
A wide range of microorganisms can infect the central nervous system (CNS). The immune response of the CNS provides limited protection against microbes penetrating the blood-brain barrier. This results in a neurological deficit and sometimes leads to high morbidity and mortality rates despite advanced therapies. For the last two decades, different studies have expanded our understanding of the molecular basis of human neuroinfectious diseases, especially concerning the contributions of mast cell interactions with other central nervous system compartments. Brain mast cells are multifunctional cells derived from the bone marrow and reside in the brain. Their proximity to blood vessels, their role as "first responders" their unique receptors systems and their ability to rapidly release pathogen responsive mediators enable them to exert a crucial defensive role in the host-defense system. This review describes key biological and physiological functions of mast cells, concerning their ability to recognize pathogens via various receptor systems, followed by a coordinated and selective mediator release upon specific interactions with pathogenic stimulating factors. The goal of this review is to direct attention to the possibilities for therapeutic applications of mast cells against bacterial and viral related infections. We also focus on opportunities for future research activating mast cells via adjuvants.
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Affiliation(s)
- Satheesh Natarajan
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Kamini Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Adeola Shobo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa; Science for Life Laboratory, Drug Discovery and Development, Platform and Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa.
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5
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Shini S, Aland RC, Bryden WL. Avian intestinal ultrastructure changes provide insight into the pathogenesis of enteric diseases and probiotic mode of action. Sci Rep 2021; 11:167. [PMID: 33420315 PMCID: PMC7794591 DOI: 10.1038/s41598-020-80714-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/24/2020] [Indexed: 01/27/2023] Open
Abstract
Epithelial damage and loss of barrier integrity occur following intestinal infections in humans and animals. Gut health was evaluated by electron microscopy in an avian model that exposed birds to subclinical necrotic enteritis (NE) and fed them a diet supplemented with the probiotic Bacillus amyloliquefaciens strain H57 (H57). Scanning electron microscopy of ileal mucosa revealed significant villus damage, including focal erosions of epithelial cells and villous atrophy, while transmission electron microscopy demonstrated severe enterocyte damage and loss of cellular integrity in NE-exposed birds. In particular, mitochondria were morphologically altered, appearing irregular in shape or swollen, and containing electron-lucent regions of matrix and damaged cristae. Apical junctional complexes between adjacent enterocytes were significantly shorter, and the adherens junction was saccular, suggesting loss of epithelial integrity in NE birds. Segmented filamentous bacteria attached to villi, which play an important role in intestinal immunity, were more numerous in birds exposed to NE. The results suggest that mitochondrial damage may be an important initiator of NE pathogenesis, while H57 maintains epithelium and improves the integrity of intestinal mucosa. Potential actions of H57 are discussed that further define the mechanisms responsible for probiotic bacteria’s role in maintaining gut health.
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Affiliation(s)
- Shaniko Shini
- School of Agriculture and Food Sciences, University of Queensland, Gatton, QLD, 4343, Australia.
| | - R Claire Aland
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD, 4071, Australia
| | - Wayne L Bryden
- School of Agriculture and Food Sciences, University of Queensland, Gatton, QLD, 4343, Australia
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Kim KS. Investigating Bacterial Penetration of the Blood-Brain Barrier for the Pathogenesis, Prevention, and Therapy of Bacterial Meningitis. ACS Infect Dis 2020; 6:34-42. [PMID: 31805229 DOI: 10.1021/acsinfecdis.9b00319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The most distressing aspect of bacterial meningitis is limited improvement in the mortality and morbidity despite attributable advances in antimicrobial chemotherapy and supportive care. A major contributing factor to such mortality and morbidity is our incomplete understanding of the pathogenesis of this disease. Microbial penetration of the blood-brain barrier, a prerequisite for the development of bacterial meningitis, exploits specific host and bacterial factors as well as host cell signaling molecules. Determination and characterization of such host and bacterial factors have been instrumental for developing our current knowledge on the pathogenesis of bacterial meningitis. In addition, counteracting such host and microbial factors has been shown to be efficacious in the prevention of bacterial meningitis. Antimicrobial therapy alone has limited efficacy in improving the outcome of bacterial meningitis. Recent studies suggest that counteracting targets contributing to bacterial penetration of the blood-brain barrier are a beneficial therapeutic adjunct to antimicrobial therapy in improving the outcome of bacterial meningitis. Taken together, these findings indicate that the elucidation of host and bacterial factors contributing to microbial penetration of the blood-brain barrier provides a novel strategy for investigating the pathogenesis, prevention, and therapy of bacterial meningitis.
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Affiliation(s)
- Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 200 North Wolfe Street, Room 3157, Baltimore, Maryland 21287, United States
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7
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Virulence Factors of Meningitis-Causing Bacteria: Enabling Brain Entry across the Blood-Brain Barrier. Int J Mol Sci 2019; 20:ijms20215393. [PMID: 31671896 PMCID: PMC6862235 DOI: 10.3390/ijms20215393] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Infections of the central nervous system (CNS) are still a major cause of morbidity and mortality worldwide. Traversal of the barriers protecting the brain by pathogens is a prerequisite for the development of meningitis. Bacteria have developed a variety of different strategies to cross these barriers and reach the CNS. To this end, they use a variety of different virulence factors that enable them to attach to and traverse these barriers. These virulence factors mediate adhesion to and invasion into host cells, intracellular survival, induction of host cell signaling and inflammatory response, and affect barrier function. While some of these mechanisms differ, others are shared by multiple pathogens. Further understanding of these processes, with special emphasis on the difference between the blood-brain barrier and the blood-cerebrospinal fluid barrier, as well as virulence factors used by the pathogens, is still needed.
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8
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Rose R, Häuser S, Stump-Guthier C, Weiss C, Rohde M, Kim KS, Ishikawa H, Schroten H, Schwerk C, Adam R. Virulence factor-dependent basolateral invasion of choroid plexus epithelial cells by pathogenic Escherichia coli in vitro. FEMS Microbiol Lett 2019; 365:5195518. [PMID: 30476042 DOI: 10.1093/femsle/fny274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/20/2018] [Indexed: 12/18/2022] Open
Abstract
Escherichia coli is the most common Gram-negative causative agent of neonatal meningitis and E. coli meningitis is associated with high morbidity and mortality. Previous research has been carried out with regard to the blood-brain barrier and thereby unveiled an assortment of virulence factors involved in E. coli meningitis. Little, however, is known about the role of the blood-cerebrospinal fluid (CSF) barrier (BCSFB), in spite of several studies suggesting that the choroid plexus (CP) is a possible entry point for E. coli into the CSF spaces. Here, we used a human CP papilloma (HIBCPP) cell line that was previously established as valid model for the study of the BCSFB. We show that E. coli invades HIBCPP cells in a polar fashion preferentially from the physiologically relevant basolateral side. Moreover, we demonstrate that deletion of outer membrane protein A, ibeA or neuDB genes results in decreased cell infection, while absence of fimH enhances invasion, although causing reduced adhesion to the apical side of HIBCPP cells. Our findings suggest that the BCSFB might constitute an entry point for E. coli into the central nervous system, and HIBCPP cells are a valuable tool for investigating E. coli entry of the BCSFB.
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Affiliation(s)
- Rebekah Rose
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Svenja Häuser
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Carolin Stump-Guthier
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Christel Weiss
- Department of Medical Statistics and Biomathematics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Hiroshi Ishikawa
- Laboratory of Clinical Regenerative Medicine, Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 1-1-1Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Horst Schroten
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Christian Schwerk
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Rüdiger Adam
- Pediatric Infectious Diseases, Department of Pediatrics, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
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9
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Abstract
A wide variety of pathogens reach the circulatory system during viral, parasitic, fungal, and bacterial infections, causing clinically diverse pathologies. Such systemic infections are usually severe and frequently life-threatening despite intensive care, in particular during the age of antibiotic resistance. Because of its position at the interface between the blood and the rest of the organism, the endothelium plays a central role during these infections. Using several examples of systemic infections, we explore the diversity of interactions between pathogens and the endothelium. These examples reveal that bacterial pathogens target specific vascular beds and affect most aspects of endothelial cell biology, ranging from cellular junction stability to endothelial cell proliferation and inflammation.
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10
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Abstract
Escherichia coli is the most common Gram-negative bacillary organism causing meningitis, and E. coli meningitis continues to be an important cause of mortality and morbidity throughout the world. Our incomplete knowledge of its pathogenesis contributes to such mortality and morbidity. Recent reports of E. coli strains producing CTX-M-type or TEM-type extended-spectrum β-lactamases create a challenge. Studies using in vitro and in vivo models of the blood-brain barrier have shown that E. coli meningitis follows a high degree of bacteremia and invasion of the blood-brain barrier. E. coli invasion of the blood-brain barrier, the essential step in the development of E. coli meningitis, requires specific microbial and host factors as well as microbe- and host-specific signaling molecules. Blockade of such microbial and host factors contributing to E. coli invasion of the blood-brain barrier is shown to be efficient in preventing E. coli penetration into the brain. The basis for requiring a high degree of bacteremia for E. coli penetration of the blood-brain barrier, however, remains unclear. Continued investigation on the microbial and host factors contributing to a high degree of bacteremia and E. coli invasion of the blood-brain barrier is likely to identify new targets for prevention and therapy of E. coli meningitis.
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11
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Baseer S, Ahmad S, Ranaghan KE, Azam SS. Towards a peptide-based vaccine against Shigella sonnei : A subtractive reverse vaccinology based approach. Biologicals 2017; 50:87-99. [DOI: 10.1016/j.biologicals.2017.08.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 07/11/2017] [Accepted: 08/08/2017] [Indexed: 02/06/2023] Open
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Loh LN, McCarthy EMC, Narang P, Khan NA, Ward TH. Escherichia coli K1 utilizes host macropinocytic pathways for invasion of brain microvascular endothelial cells. Traffic 2017; 18:733-746. [PMID: 28799243 DOI: 10.1111/tra.12508] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/07/2017] [Accepted: 08/07/2017] [Indexed: 01/06/2023]
Abstract
Eukaryotic cells utilize multiple endocytic pathways for specific uptake of ligands or molecules, and these pathways are commonly hijacked by pathogens to enable host cell invasion. Escherichia coli K1, a pathogenic bacterium that causes neonatal meningitis, invades the endothelium of the blood-brain barrier, but the entry route remains unclear. Here, we demonstrate that the bacteria trigger an actin-mediated uptake route, stimulating fluid phase uptake, membrane ruffling and macropinocytosis. The route of uptake requires intact lipid rafts as shown by cholesterol depletion. Using a variety of perturbants we demonstrate that small Rho GTPases and their downstream effectors have a significant effect on bacterial invasion. Furthermore, clathrin-mediated endocytosis appears to play an indirect role in E. coli K1 uptake. The data suggest that the bacteria effect a complex interplay between the Rho GTPases to increase their chances of uptake by macropinocytosis into human brain microvascular endothelial cells.
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Affiliation(s)
- Lip Nam Loh
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Elizabeth M C McCarthy
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Priyanka Narang
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Naveed A Khan
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, Selangor, Malaysia
| | - Theresa H Ward
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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13
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Chang AC, Krishnan S, Prasadarao NV. The effects of cytotoxic necrotizing factor 1 expression in the uptake of Escherichia coli K1 by macrophages and the onset of meningitis in newborn mice. Virulence 2016; 7:806-18. [PMID: 27221788 DOI: 10.1080/21505594.2016.1192730] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Macrophages are a permissive niche for E. coli K1 multiplication for which the interaction of the bacterial outer membrane protein A and its cognate receptor CD64 are critical. Using in vitro immunofluorescence and live microscopy with ex vivo macrophage cultures from RFP-Lifeact mice, we show that cytotoxic necrotizing factor 1 (CNF1) secreted by E. coli K1 sequesters cellular actin toward microspike formation, thereby limiting actin availability for OmpA-mediated bacterial invasion. Surprisingly, the observed effects of CNF1 occur despite the absence of 67-kDa laminin receptor in macrophages. Concomitantly, the CNF1 deletion mutant of E. coli K1 (Δcnf1) invades macrophages and the brains of newborn mice in greater numbers compared to wild-type. However, the Δcnf1 strain induces less severe pathology in the brain. These results suggest a novel role for CNF1 in limiting E. coli K1 entry into macrophages while exacerbating disease severity in the brains of newborn mice.
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Affiliation(s)
- Alexander C Chang
- a Division of Infectious Diseases and Department of Pediatrics , Children's Hospital Los Angeles , Los Angeles , CA , USA
| | - Subramanian Krishnan
- a Division of Infectious Diseases and Department of Pediatrics , Children's Hospital Los Angeles , Los Angeles , CA , USA
| | - Nemani V Prasadarao
- a Division of Infectious Diseases and Department of Pediatrics , Children's Hospital Los Angeles , Los Angeles , CA , USA.,b Department of Surgery , Children's Hospital Los Angeles , Los Angeles , CA , USA.,c Keck School of Medicine , University of Southern California , Los Angeles , CA , USA
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14
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He X, Shi X, Puthiyakunnon S, Zhang L, Zeng Q, Li Y, Boddu S, Qiu J, Lai Z, Ma C, Xie Y, Long M, Du L, Huang SH, Cao H. CD44-mediated monocyte transmigration across Cryptococcus neoformans-infected brain microvascular endothelial cells is enhanced by HIV-1 gp41-I90 ectodomain. J Biomed Sci 2016; 23:28. [PMID: 26897523 PMCID: PMC4761181 DOI: 10.1186/s12929-016-0247-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/15/2016] [Indexed: 12/19/2022] Open
Abstract
Background Cryptococcus neoformans (Cn) is an important opportunistic pathogen in the immunocompromised people, including AIDS patients, which leads to fatal cryptococcal meningitis with high mortality rate. Previous researches have shown that HIV-1 gp41-I90 ectodomain can enhance Cn adhesion to and invasion of brain microvascular endothelial cell (BMEC), which constitutes the blood brain barrier (BBB). However, little is known about the role of HIV-1 gp41-I90 in the monocyte transmigration across Cn-infected BBB. In the present study, we provide evidence that HIV-1 gp41-I90 and Cn synergistically enhance monocytes transmigration across the BBB in vitro and in vivo. The underlying mechanisms for this phenomenon require further study. Methods In this study, the enhancing role of HIV-1 gp41-I90 in monocyte transmigration across Cn-infected BBB was demonstrated by performed transmigration assays in vitro and in vivo. Results Our results showed that the transmigration rate of monocytes are positively associated with Cn and/or HIV-1 gp41-I90, the co-exposure (HIV-1 gp41-I90 + Cn) group showed a higher THP-1 transmigration rate (P < 0.01). Using CD44 knock-down HBMEC or CD44 inhibitor Bikunin in the assay, the facilitation of transmigration rates of monocyte enhanced by HIV-1 gp41-I90 was significantly suppressed. Western blotting analysis and biotin/avidin enzyme-linked immunosorbent assays (BA-ELISAs) showed that Cn and HIV-1 gp41-I90 could increase the expression of CD44 and ICAM-1 on the HBMEC. Moreover, Cn and/or HIV-1 gp41-I90 could also induce CD44 redistribution to the membrane lipid rafts. By establishing the mouse cryptococcal meningitis model, we found that HIV-1 gp41-I90 and Cn could synergistically enhance the monocytes transmigration, increase the BBB permeability and injury in vivo. Conclusions Collectively, our findings suggested that HIV-1 gp41-I90 ectodomain can enhance the transmigration of THP-1 through Cn-infected BBB, which may be mediated by CD44. This novel study enlightens the future prospects to elaborate the inflammatory responses induced by HIV-1 gp41-I90 ectodomain and to effectively eliminate the opportunistic infections in AIDS patients.
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Affiliation(s)
- Xiaolong He
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Xiaolu Shi
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Santhosh Puthiyakunnon
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Like Zhang
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Qing Zeng
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Yan Li
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Swapna Boddu
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Jiawen Qiu
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Zhihao Lai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Chao Ma
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Yulong Xie
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Min Long
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Lei Du
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
| | - Sheng-He Huang
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. .,Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA, 90027, USA.
| | - Hong Cao
- Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
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15
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Dando SJ, Mackay-Sim A, Norton R, Currie BJ, St John JA, Ekberg JAK, Batzloff M, Ulett GC, Beacham IR. Pathogens penetrating the central nervous system: infection pathways and the cellular and molecular mechanisms of invasion. Clin Microbiol Rev 2014; 27:691-726. [PMID: 25278572 PMCID: PMC4187632 DOI: 10.1128/cmr.00118-13] [Citation(s) in RCA: 273] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The brain is well protected against microbial invasion by cellular barriers, such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). In addition, cells within the central nervous system (CNS) are capable of producing an immune response against invading pathogens. Nonetheless, a range of pathogenic microbes make their way to the CNS, and the resulting infections can cause significant morbidity and mortality. Bacteria, amoebae, fungi, and viruses are capable of CNS invasion, with the latter using axonal transport as a common route of infection. In this review, we compare the mechanisms by which bacterial pathogens reach the CNS and infect the brain. In particular, we focus on recent data regarding mechanisms of bacterial translocation from the nasal mucosa to the brain, which represents a little explored pathway of bacterial invasion but has been proposed as being particularly important in explaining how infection with Burkholderia pseudomallei can result in melioidosis encephalomyelitis.
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Affiliation(s)
- Samantha J Dando
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Alan Mackay-Sim
- Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Robert Norton
- Townsville Hospital, Townsville, Queensland, Australia
| | - Bart J Currie
- Menzies School of Health Research and Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - James A St John
- Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Jenny A K Ekberg
- Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Michael Batzloff
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Glen C Ulett
- School of Medical Science and Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
| | - Ifor R Beacham
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
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16
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Meraz IM, Arikawa K, Ogasawara J, Hase A, Nishikawa Y. Epithelial Cells Secrete Interleukin-8 in Response to Adhesion and Invasion of Diffusely AdheringEscherichia coliLacking Afa/Dr Genes. Microbiol Immunol 2013; 50:159-69. [PMID: 16547413 DOI: 10.1111/j.1348-0421.2006.tb03781.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Escherichia coli that sparsely adhere to human epithelial cells are known as diffusely adherent E. coli (DAEC), and the role of the Afa/Dr family of adhesins is now understood. Strains that do not possess Afa/Dr, however, comprise another group of DAEC, of which the pathogenicity remains unknown. The ability to induce interleukin-8 (IL-8) secretion from intestinal epithelial cells might be a feature of enterovirulent bacteria. We previously found that some Afa/Dr DAEC strains induce IL-8 by stimulating epithelial cells with flagella. The present study examines whether non-Afa/Dr DAEC can induce IL-8 in epithelial cells (HEp-2, INT407, and T84). Among 21 strains, 11 (52%; 11/21) induced as much IL-8 as high inducer strains of Afa/Dr DAEC. Adhesion did not significantly differ between high and low inducers; therefore diffuse adhesion alone is probably insufficient to induce IL-8. It was shown that IL-8 induction and the number of intracellular bacteria directly correlated. Wortmannin, an inhibitor of the phosphatidylinositol-3-phosphate kinase, reduced both intracellular bacteria and IL-8 secretion. Motile strains were significantly more prevalent among high (10/11) than low (4/10) inducers. However, 4 low invasive strains hardly induced IL-8 despite their motility. In conclusion, some non-Afa/Dr DAEC invoke the induction of high levels of inflammatory cytokines. Unlike Afa/Dr DAEC, however, non-Afa/Dr strains may require invasion to cause strong induction. These non-Afa/Dr high inducers can be enteropathogenic for the cytokine-inducing properties.
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Affiliation(s)
- Ismail Mustafa Meraz
- Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, Osaka 558-8585, Japan
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17
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Doran KS, Banerjee A, Disson O, Lecuit M. Concepts and mechanisms: crossing host barriers. Cold Spring Harb Perspect Med 2013; 3:a010090. [PMID: 23818514 PMCID: PMC3685877 DOI: 10.1101/cshperspect.a010090] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The human body is bordered by the skin and mucosa, which are the cellular barriers that define the frontier between the internal milieu and the external nonsterile environment. Additional cellular barriers, such as the placental and the blood-brain barriers, define protected niches within the host. In addition to their physiological roles, these host barriers provide both physical and immune defense against microbial infection. Yet, many pathogens have evolved elaborated mechanisms to target this line of defense, resulting in a microbial invasion of cells constitutive of host barriers, disruption of barrier integrity, and systemic dissemination and invasion of deeper tissues. Here we review representative examples of microbial interactions with human barriers, including the intestinal, placental, and blood-brain barriers, and discuss how these microbes adhere to, invade, breach, or compromise these barriers.
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Affiliation(s)
- Kelly S Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California 92182, USA.
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18
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Coureuil M, Join-Lambert O, Lécuyer H, Bourdoulous S, Marullo S, Nassif X. Pathogenesis of meningococcemia. Cold Spring Harb Perspect Med 2013; 3:3/6/a012393. [PMID: 23732856 DOI: 10.1101/cshperspect.a012393] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neisseria meningitidis is responsible for two major diseases: cerebrospinal meningitis and/or septicemia. The latter can lead to a purpura fulminans, an often-fatal condition owing to the associated septic shock. These two clinical aspects of the meningococcal infection are consequences of a tight interaction of meningococci with host endothelial cells. This interaction, mediated by the type IV pili, is responsible for the formation of microcolonies on the apical surface of the cells. This interaction is followed by the activation of signaling pathways in the host cells leading to the formation of a microbiological synapse. A low level of bacteremia is likely to favor the colonization of brain vessels, leading to bacterial meningitis, whereas the colonization of a large number of vessels by a high number of bacteria is responsible for one of the most severe forms of septic shock observed.
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19
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Confer AW, Ayalew S. The OmpA family of proteins: Roles in bacterial pathogenesis and immunity. Vet Microbiol 2013; 163:207-22. [DOI: 10.1016/j.vetmic.2012.08.019] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 08/23/2012] [Indexed: 10/27/2022]
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20
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Salmeri M, Motta C, Anfuso CD, Amodeo A, Scalia M, Toscano MA, Alberghina M, Lupo G. VEGF receptor-1 involvement in pericyte loss induced by Escherichia coli in an in vitro model of blood brain barrier. Cell Microbiol 2013; 15:1367-84. [PMID: 23421875 DOI: 10.1111/cmi.12121] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 02/04/2013] [Accepted: 02/06/2013] [Indexed: 12/18/2022]
Abstract
The key aspect of neonatal meningitis is related to the ability of pathogens to invade the blood-brain barrier (BBB) and to penetrate the central nervous system. In the present study we show that, in an in vitro model of BBB, on the basis of co-culturing primary bovine brain endothelial cells (BBEC) and primary bovine retinal pericytes (BRPC), Escherichia coli infection determines changes of transendothelial electrical resistance (TEER) and permeability (Pe) to sodium fluorescein. In the co-culture model, within BBEC, bacteria are able to stimulate cytosolic and Ca(2+)-independent phospholipase A2 (cPLA2 and iPLA2 ) enzyme activities. In supernatants of E. coli-stimulated co-cultures, an increase in prostaglandins (PGE2) and VEGF production in comparison with untreated co-cultures were found. Incubation with E. coli in presence of AACOCF3 or BEL caused a decrease of PGE2 and VEGF release. SEM and TEM images of BBEC and BRPC showed E. coli adhesion to BBEC and BRPC but only in BBEC the invasion occurs. VEGFR-1 but not VEGFR-2 blockade by the specific antibody reduced E. coli invasion in BBEC. In our model of BBB infection, a significant loss of BRPC was observed. Following VEGFR-1, but not VEGFR-2 blockade, or in presence of AACOCF3 or BEL, elevated TEER values, reduced permeability and BRPC loss were found. These data suggest that VEGFR-1 negatively regulates BRPC survival and its blockade protects the barrier integrity. PGs and VEGF could exert a biological effect on BBB, probably by BRPC coverage ablation, thus increasing BBB permeability. Our results show the role played by the BBEC as well as BRPC during a bacterial attack on BBB. A better understanding of the mechanisms by which E. coli enter the nervous system and how bacteria alter the communication between endothelial cells and pericytes may provide exciting new insight for clinical intervention.
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Affiliation(s)
- Mario Salmeri
- Department of Bio-medical Sciences, University of Catania, Catania, Italy
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21
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Krishnan S, Chen S, Turcatel G, Arditi M, Prasadarao NV. Regulation of Toll-like receptor 2 interaction with Ecgp96 controls Escherichia coli K1 invasion of brain endothelial cells. Cell Microbiol 2012; 15:63-81. [PMID: 22963587 DOI: 10.1111/cmi.12026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 08/16/2012] [Accepted: 09/04/2012] [Indexed: 01/19/2023]
Abstract
The interaction of outer membrane protein A (OmpA) with its receptor, Ecgp96 (a homologue of Hsp90β), is critical for the pathogenesis of Escherichia coli K1 meningitis. Since Hsp90 chaperones Toll-like receptors (TLRs), we examined the role of TLRs in E. coli K1 infection. Herein, we show that newborn TLR2(-/-) mice are resistant to E. coli K1 meningitis, while TLR4(-/-) mice succumb to infection sooner. In vitro, OmpA+ E. coli infection selectively upregulates Ecgp96 and TLR2 in human brain microvascular endothelial cells (HBMEC), whereas OmpA- E. coli upregulates TLR4 in these cells. Furthermore, infection with OmpA+ E. coli causes Ecgp96 and TLR2 translocate to the plasma membrane of HBMEC as a complex. Immunoprecipitation studies of the plasma membrane fractions from infected HBMEC reveal that the C termini of Ecgp96 and TLR2 are critical for OmpA+ E. coli invasion. Knockdown of TLR2 using siRNA results in inefficient membrane translocation of Ecgp96 and significantly reduces invasion. In addition, the interaction of Ecgp96 andTLR2 induces a bipartite signal, one from Ecgp96 through PKC-α while the other from TLR2 through MyD88, ERK1/2 and NF-κB. This bipartite signal ultimately culminates in the efficient production of NO, which in turn promotes E. coli K1 invasion of HBMEC.
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Affiliation(s)
- Subramanian Krishnan
- Division of Infectious Diseases, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
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22
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Kim JC, Crary B, Chang YC, Kwon-Chung KJ, Kim KJ. Cryptococcus neoformans activates RhoGTPase proteins followed by protein kinase C, focal adhesion kinase, and ezrin to promote traversal across the blood-brain barrier. J Biol Chem 2012; 287:36147-57. [PMID: 22898813 DOI: 10.1074/jbc.m112.389676] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis. Previous studies have demonstrated that Cryptococcus binding and invasion of human brain microvascular endothelial cells (HBMEC) is a prerequisite for transmigration across the blood-brain barrier. However, the molecular mechanism involved in the cryptococcal blood-brain barrier traversal is poorly understood. In this study we examined the signaling events in HBMEC during interaction with C. neoformans. Analysis with inhibitors revealed that cryptococcal association, invasion, and transmigration require host actin cytoskeleton rearrangement. Rho pulldown assays revealed that Cryptococcus induces activation of three members of RhoGTPases, e.g. RhoA, Rac1, and Cdc42, and their activations are required for cryptococcal transmigration across the HBMEC monolayer. Western blot analysis showed that Cryptococcus also induces phosphorylation of focal adhesion kinase (FAK), ezrin, and protein kinase C α (PKCα), all of which are involved in the rearrangement of host actin cytoskeleton. Down-regulation of FAK, ezrin, or PKCα by shRNA knockdown, dominant-negative transfection, or inhibitors significantly reduces cryptococcal ability to traverse the HBMEC monolayer, indicating their positive role in cryptococcal transmigration. In addition, activation of RhoGTPases is the upstream event for phosphorylation of FAK, ezrin, and PKCα during C. neoformans-HBMEC interaction. Taken together, our findings demonstrate that C. neoformans activates RhoGTPases and subsequently FAK, ezrin, and PKCα to promote their traversal across the HBMEC monolayer, which is the critical step for cryptococcal brain infection and development of meningitis.
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Affiliation(s)
- Jong-Chul Kim
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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23
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van Sorge NM, Doran KS. Defense at the border: the blood-brain barrier versus bacterial foreigners. Future Microbiol 2012; 7:383-94. [PMID: 22393891 DOI: 10.2217/fmb.12.1] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Bacterial meningitis is among the top ten causes of infectious disease-related deaths worldwide, with up to half of the survivors left with permanent neurological sequelae. The blood-brain barrier (BBB), composed mainly of specialized brain microvascular endothelial cells, maintains biochemical homeostasis in the CNS by regulating the passage of nutrients, molecules and cells from the blood to the brain. Despite its highly restrictive nature, certain bacterial pathogens are able to gain entry into the CNS resulting in serious disease. In recent years, important advances have been made in understanding the molecular and cellular events that are involved in the development of bacterial meningitis. In this review, we summarize the progress made in elucidating the molecular mechanisms of bacterial BBB-crossing, highlighting common themes of host-pathogen interaction, and the potential role of the BBB in innate defense during infection.
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Affiliation(s)
- Nina M van Sorge
- University Medical Center Utrecht, Medical Microbiology, Heidelberglaan 100, G04.614, 3584 GX Utrecht, The Netherlands
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24
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Coureuil M, Join-Lambert O, Lécuyer H, Bourdoulous S, Marullo S, Nassif X. Mechanism of meningeal invasion by Neisseria meningitidis. Virulence 2012; 3:164-72. [PMID: 22366962 PMCID: PMC3396695 DOI: 10.4161/viru.18639] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The blood-cerebrospinal fluid barrier physiologically protects the meningeal spaces from blood-borne bacterial pathogens, due to the existence of specialized junctional interendothelial complexes. Few bacterial pathogens are able to reach the subarachnoidal space and among those, Neisseria meningitidis is the one that achieves this task the most constantly when present in the bloodstream. Meningeal invasion is a consequence of a tight interaction of meningococci with brain endothelial cells. This interaction, mediated by the type IV pili, is responsible for the formation of microcolonies on the apical surface of the cells. This interaction is followed by the activation of signaling pathways in the host cells leading to the formation of endothelial docking structures resembling those elicited by the interaction of leukocytes with endothelial cells during extravasation. The consequence of these bacterial-induced signaling events is the recruitment of intercellular junction components in the docking structure and the subsequent opening of the intercellular junctions.
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25
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Irradiation induces homing of donor endothelial progenitor cells in allogeneic hematopoietic stem cell transplantation. Int J Hematol 2012; 95:189-97. [DOI: 10.1007/s12185-011-1000-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 12/13/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
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26
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Loh LN, Ward TH. Escherichia coli K1 invasion of human brain microvascular endothelial cells. Methods Enzymol 2012; 506:93-113. [PMID: 22341221 DOI: 10.1016/b978-0-12-391856-7.00030-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The pathogenic Escherichia coli strain E. coli K1 is a primary causative agent of neonatal meningitis. Understanding how these bacteria cross the blood-brain barrier is vital to develop therapeutics. Here, we describe the use of live-cell imaging techniques to study E. coli K1 interactions with cellular markers following infection of human brain microvascular endothelial cells, a model system of the blood-brain barrier. We also discuss optimization of endothelial cell transfection conditions using nonviral transfection technique, bacterial labeling techniques, and in vitro assays to screen for fluorescent bacteria that retain their ability to invade host cells.
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Affiliation(s)
- Lip Nam Loh
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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27
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Nedbalcova K, Kucerova Z, Krejci J, Tesarik R, Gopfert E, Kummer V, Leva L, Kudlackova H, Ondriasova R, Faldyna M. Passive immunisation of post-weaned piglets using hyperimmune serum against experimental Haemophilus parasuis infection. Res Vet Sci 2011; 91:225-9. [DOI: 10.1016/j.rvsc.2010.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 11/26/2010] [Accepted: 12/09/2010] [Indexed: 11/28/2022]
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28
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Gandhi G, Londoño D, Whetstine CR, Sethi N, Kim KS, Zückert WR, Cadavid D. Interaction of variable bacterial outer membrane lipoproteins with brain endothelium. PLoS One 2010; 5:e13257. [PMID: 21063459 PMCID: PMC2962627 DOI: 10.1371/journal.pone.0013257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 09/07/2010] [Indexed: 11/29/2022] Open
Abstract
Background Previously we reported that the variable outer membrane lipoprotein Vsp1 from the relapsing fever spirochete Borrelia turicatae disseminates from blood to brain better than the closely related Vsp2 [1]. Here we studied the interaction between Vsp1 and Vsp2 with brain endothelium in more detail. Methodology/Principal Findings We compared Vsp1 to Vsp2 using human brain microvascular endothelial cell (HBMEC) association assays with aminoacid radiolabeled Vsp-expressing clones of recombinant Borrelia burgdorferi and lanthanide-labeled purified lipidated Vsp1 (LVsp1) and Vsp2 (LVsp2) and inoculations of the lanthanide-labeled proteins into mice. The results showed that heterologous expression of LVsp1 or LVsp2 in B. burgdorferi increased its association with HBMEC to a similar degree. Purified lanthanide-labeled lipidated Vsp1 (LVsp1) and LVsp2 by themselves were capable of associating with HBMEC. The association of LVsp1 with brain endothelium was time-dependent, saturable, and required the lipidation. The association of Vsp1 with HBMEC was inhibited by incubation at lower temperature or with excess unlabeled LVsp1 or LVsp2 but not with excess rVsp1 or mouse albumin or an anti Vsp1 monoclonal antibody. The association of LVsp2 with HBMEC and its movement from blood to brain parenchyma significantly increased in the presence of LVsp1. Conclusions/Significance Variable bacterial outer membrane lipoproteins interact with brain endothelium differently; the lipidation and variable features at the protein dome region are key modulators of this interaction.
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Affiliation(s)
- Gaurav Gandhi
- Department of Neurology and Neuroscience and Center for the Study of Emerging Pathogens at UMDNJ-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Diana Londoño
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Neurology and Neuroscience and Center for the Study of Emerging Pathogens at UMDNJ-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Christine R. Whetstine
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Nilay Sethi
- Department of Neurology and Neuroscience and Center for the Study of Emerging Pathogens at UMDNJ-New Jersey Medical School, Newark, New Jersey, United States of America
| | - Kwang S. Kim
- Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Wolfram R. Zückert
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Diego Cadavid
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Neurology and Neuroscience and Center for the Study of Emerging Pathogens at UMDNJ-New Jersey Medical School, Newark, New Jersey, United States of America
- * E-mail:
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29
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Zhu L, Maruvada R, Sapirstein A, Malik KU, Peters-Golden M, Kim KS. Arachidonic acid metabolism regulates Escherichia coli penetration of the blood-brain barrier. Infect Immun 2010; 78:4302-10. [PMID: 20696828 PMCID: PMC2950368 DOI: 10.1128/iai.00624-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 07/09/2010] [Accepted: 07/30/2010] [Indexed: 01/29/2023] Open
Abstract
Escherichia coli K1 meningitis occurs following penetration of the blood-brain barrier, but the underlying mechanisms involved in E. coli penetration of the blood-brain barrier remain incompletely understood. We have previously shown that host cytosolic phospholipase A(2)α (cPLA(2)α) contributes to E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, but the underlying mechanisms remain unclear. cPLA(2)α selectively liberates arachidonic acid from membrane phospholipids. Here, we provide the first direct evidence that host 5-lipoxygenase and lipoxygenase products of arachidonic acid, cysteinyl leukotrienes (LTs), contribute to E. coli K1 invasion of HBMEC and penetration into the brain, and their contributions involve protein kinase C alpha (PKCα). These findings demonstrate that arachidonic acid metabolism regulates E. coli penetration of the blood-brain barrier, and studies are needed to further elucidate the mechanisms involved with metabolic products of arachidonic acid for their contribution to E. coli invasion of the blood-brain barrier.
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Affiliation(s)
- Longkun Zhu
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Ravi Maruvada
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Adam Sapirstein
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Kafait U. Malik
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Marc Peters-Golden
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 North Wolfe St., Room 3157, Baltimore, Maryland 21287, Department of Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Meyer 297-A, Baltimore, Maryland 21287, Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, 6301 MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109
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Goonetilleke UR, Scarborough M, Ward SA, Gordon SB. Proteomic analysis of cerebrospinal fluid in pneumococcal meningitis reveals potential biomarkers associated with survival. J Infect Dis 2010; 202:542-50. [PMID: 20608875 DOI: 10.1086/654819] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Patients with pneumococcal meningitis often die or have severe neurological damage despite optimal antibiotic therapy. New or improved therapy is required. The delivery of new interventions will require an improved understanding of the disease pathogenesis. Our objective was to learn more about the pathophysiology of severe meningitis through the interpretation of differences in the proteomic profile of cerebrospinal fluid (CSF) from patients with meningitis. METHODS Two-dimensional polyacrylamide gel electrophoresis of CSF from normal subjects (controls, n = 10) and patients with pneumococcal meningitis (n = 20) was analyzed. Spot differences were compared and identified between controls, nonsurvivors (n = 9), and survivors (n = 11). RESULTS Protein concentration in CSF of patients with meningitis was 4-fold higher than in CSF of control subjects (7.0 mg/mL vs 0.23 mg/mL; P < .01). A mean of 2466 discrete protein spots was present in CSF of patients with meningitis. Thirty-four protein spots were differentially expressed in CSF of nonsurvivors, compared with survivors. None of these protein spots were observed in CSF of control subjects. CONCLUSIONS Proteomic screening of CSF yields potential biomarkers capable of differentiating control subjects from nonsurvivors and survivors of meningitis. Proteins involved in the inflammatory process and central metabolism were represented in the differentially expressed protein repertoire.
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Affiliation(s)
- Upali R Goonetilleke
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom.
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31
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Vascular endothelial growth factor receptor 1 contributes to Escherichia coli K1 invasion of human brain microvascular endothelial cells through the phosphatidylinositol 3-kinase/Akt signaling pathway. Infect Immun 2010; 78:4809-16. [PMID: 20805333 DOI: 10.1128/iai.00377-10] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Escherichia coli is the most common Gram-negative organism causing neonatal meningitis. Previous studies demonstrated that E. coli K1 invasion of brain microvascular endothelial cells (BMEC) is required for penetration into the central nervous system, but the microbe-host interactions that are involved in this process remain incompletely understood. Here we report the involvement of vascular endothelial growth factor receptor 1 (VEGFR1) expressed on human brain microvascular endothelial cells (HBMEC) in E. coli K1 invasion of HBMEC. Our results showed that treatment of confluent HBMEC with pan-VEGFR inhibitors significantly inhibited E. coli K1 invasion of HBMEC. Immunofluorescence results indicated the colocalization of VEGFR1 with E. coli K1 during bacterial invasion of HBMEC. The E. coli-induced actin cytoskeleton rearrangements in HBMEC were blocked by VEGFR inhibitors but not by VEGFR2-specific inhibitors. The small interfering RNA (siRNA) knockdown of VEGFR1 in HBMEC significantly attenuated E. coli invasion and the concomitant actin filament rearrangement. Furthermore, we found an increased association of VEGFR1 with the p85 subunit of phosphatidylinositol 3-kinase (PI3K) in HBMEC infected with E. coli K1 and that E. coli K1-triggered Akt activation in HBMEC was blocked by VEGFR1 siRNA and VEGFR inhibitors. Taken together, our results demonstrate that VEGFR1 contributes to E. coli K1 invasion of HBMEC via recruitment of the PI3K/Akt signaling pathway.
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32
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Daneman R, Rescigno M. The gut immune barrier and the blood-brain barrier: are they so different? Immunity 2009; 31:722-35. [PMID: 19836264 DOI: 10.1016/j.immuni.2009.09.012] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Accepted: 09/29/2009] [Indexed: 12/18/2022]
Abstract
In order to protect itself from a diverse set of environmental pathogens and toxins, the body has developed a number of barrier mechanisms to limit the entry of potential hazards. Here, we compare two such barriers: the gut immune barrier, which is the primary barrier against pathogens and toxins ingested in food, and the blood-brain barrier, which protects the central nervous system from pathogens and toxins in the blood. Although each barrier provides defense in very different environments, there are many similarities in their mechanisms of action. In both cases, there is a physical barrier formed by a cellular layer that tightly regulates the movement of ions, molecules, and cells between two tissue spaces. These barrier cells interact with different cell types, which dynamically regulate their function, and with a different array of immune cells that survey the physical barrier and provide innate and adaptive immunity.
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Affiliation(s)
- Richard Daneman
- University of California, San Francisco, Department of Anatomy, San Francisco, CA 94143-0452, USA.
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33
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Yao Y, Xie Y, Perace D, Zhong Y, Lu J, Tao J, Guo X, Kim KS. The type III secretion system is involved in the invasion and intracellular survival of Escherichia coli K1 in human brain microvascular endothelial cells. FEMS Microbiol Lett 2009; 300:18-24. [PMID: 19758329 DOI: 10.1111/j.1574-6968.2009.01763.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Type III secretion systems (T3SSs) have been documented in many Gram-negative bacteria, including enterohemorrhagic Escherichia coli. We have previously shown the existence of a putative T3SS in meningitis-causing E. coli K1 strains, referred to as E. coli type III secretion 2 (ETT2). The sequence of ETT2 in meningitis-causing E. coli K1 strain EC10 (O7:K1) revealed that ETT2 comprises the epr, epa and eiv genes, but bears mutations, deletions and insertions. We constructed the EC10 mutants deleted of ETT2 or eivA gene, and their contributions to bacterial pathogenesis were evaluated in human brain microvascular endothelial cells (HBMECs). The deletion mutant of ETT2 exhibited defects in invasion and intracellular survival compared with the parental E. coli K1 strain EC10. The mutant deleted of eivA within ETT2 was also significantly defective in invasion and intracellular survival in HBMECs, and the defects of the eiv mutant were restored to the levels of the parent strain EC10 by transcomplementation. These findings suggest that ETT2 plays a role in the pathogenesis of E. coli K1 infection, including meningitis.
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Affiliation(s)
- Yufeng Yao
- Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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34
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OmpA is the critical component for Escherichia coli invasion-induced astrocyte activation. J Neuropathol Exp Neurol 2009; 68:677-90. [PMID: 19458541 DOI: 10.1097/nen.0b013e3181a77d1e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Escherichia coli is the major Gram-negative bacterial pathogen in neonatal meningitis. Outer membrane protein A (OmpA) is a conserved major protein in the E. coli outer membrane and is involved in several host-cell interactions. To characterize the role of OmpA in the invasion of astrocytes by E. coli, we investigated OmpA-positive and OmpA-negative E. coli strains. Outer membrane protein A E44, E105, and E109 strains adhered to and invaded C6 glioma cells 10- to 15-fold more efficiently than OmpA-negative strains. Actin rearrangement, protein tyrosine kinase, and phosphoinositide 3-kinase activation were required for OmpA-mediated invasion by E. coli. In vitro infection of C6 cells and intracerebral injection into mice of the E44 strain induced expression of the astrocyte differentiation marker glial fibrillary acidic protein and the inflammatory mediators cyclooxygenase 2 and nitric oxide synthase 2. After intracerebral infection with E44, all C57BL/6 mice died within 36hours, whereas 80% of mice injected with E44 premixed with recombinant OmpA protein survived. Astrocyte activation and neutrophil infiltration were reduced in brain tissue sections in the mice given OmpA. Taken together, these data suggest that OmpA-mediated invasion plays an important role in the early stage of E.coli-induced brain damage, and that it may have therapeutic use in E. coli meningitis.
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35
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Identification of Mannheimia haemolytica adhesins involved in binding to bovine bronchial epithelial cells. Infect Immun 2008; 77:446-55. [PMID: 18981250 DOI: 10.1128/iai.00312-08] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mannheimia haemolytica, a commensal organism of the upper respiratory tract in cattle, is the principal bacterial pathogen associated with the bovine respiratory disease complex. Adherence to the respiratory mucosa is a crucial event in its pathogenesis. However, the bacterial components that contribute to this process are not fully characterized. In this study, we demonstrated that M. haemolytica adhered to bovine bronchial epithelial cells (BBEC) in vitro and that adherence was inhibited by anti-M. haemolytica antibody. Western blot analysis of M. haemolytica proteins that bind to BBEC showed a dominant protein band with an apparent molecular mass of approximately 30 kDa. Peptide sequences for the 30-kDa BBEC-binding proteins, as determined by liquid chromatography-tandem mass spectrometry, matched two M. haemolytica surface proteins: heat-modifiable outer membrane protein A (OmpA) and lipoprotein 1 (Lpp1). Western blotting showed that the 30-kDa protein band is recognized by both anti-M. haemolytica OmpA and anti-Lpp1 antibodies. Furthermore, incubation with anti-OmpA and anti-Lpp1 antibodies significantly inhibited M. haemolytica binding to BBEC monolayers. In summary, these results suggest that OmpA and Lpp1 contribute to adherence of M. haemolytica to bovine respiratory epithelial cells.
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36
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Maruvada R, Argon Y, Prasadarao NV. Escherichia coli interaction with human brain microvascular endothelial cells induces signal transducer and activator of transcription 3 association with the C-terminal domain of Ec-gp96, the outer membrane protein A receptor for invasion. Cell Microbiol 2008; 10:2326-38. [PMID: 18662321 PMCID: PMC2579944 DOI: 10.1111/j.1462-5822.2008.01214.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Our inability to develop new therapeutic strategies to prevent meningitis due to Escherichia coli K1 is attributed to our incomplete understanding of the pathophysiology of the disease. Previously, we demonstrated that outer membrane protein A of E. coli interacts with a gp96 homologue, Ec-gp96, on human brain microvascular endothelial cells (HBMEC) for invasion. However, signalling events mediated by Ec-gp96 that allow internalization of E. coli are incompletely understood. Here, we demonstrate that signal transducer and activator of transcription 3 (Stat3) activation and its interaction with Ec-gp96 were critical for E. coli invasion. The activated Stat3 was colocalized with Ec-gp96 at the actin condensation sites, and overexpressing a dominant negative (DN) form of Stat3 in HBMEC significantly abrogated the invasion. Furthermore, overexpression of Ec-gp96Delta200, the C-terminal 214-amino-acid truncated Ec-gp96, prevented the invasion of E. coli in HBMEC. In contrast, lack of ATP binding by gp96 did not affect the invasion. Overexpression of DN forms of either phosphatidyl inositol-3 kinase (PI3-kinase) subunit p85 or protein kinase C-alpha (PKC-alpha) had no effect on the activation of Stat3 and its association with Ec-gp96, whereas overexpression of DN-Stat3 abolished the activation of both PI3-kinase and PKC-alpha. Together, our findings identified a novel interaction of Stat3 with Ec-gp96, upstream of PI3-kinase and PKC-alpha activation that is required for the invasion of E. coli into HBMEC.
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Affiliation(s)
- Ravi Maruvada
- Division of Infectious Diseases, The Saban Research Institute, Childrens Hospital Los Angeles
| | - Yair Argon
- Division of Cell Pathology, Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nemani V. Prasadarao
- Division of Infectious Diseases, The Saban Research Institute, Childrens Hospital Los Angeles
- Keck School of Medicine, University of Southern California, Los Angeles, CA 90027, USA
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37
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Smith MW, Gumbleton M. Endocytosis at the blood–brain barrier: From basic understanding to drug delivery strategies. J Drug Target 2008; 14:191-214. [PMID: 16777679 DOI: 10.1080/10611860600650086] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The blood-brain barrier (BBB) protects the central nervous system (CNS) from potentially harmful xenobiotics and endogenous molecules. Anatomically, it comprises the brain microvasculature whose functionality is nevertheless influenced by associated astrocyte, pericyte and neuronal cells. The highly restrictive paracellular pathway within brain microvasculature restricts significant CNS penetration to only those drugs whose physicochemical properties afford ready penetration into hydrophobic cell membranes or are capable of exploiting endogenous active transport processes such as solute carriers or endocytosis pathways. Endocytosis at the BBB is an essential pathway by which the brain obtains its nutrients and affords communication with the periphery. The development of strategies to exploit these endocytic pathways for the purposes of drug delivery to the CNS is still an immature field although some impressive results have been documented with the targeting of particular receptors. This current article initially provides an overview of general endocytosis processes and pathways showing evidence of their functional existence within the BBB. Subsequent sections provide, in an entity-specific manner, comprehensive reviews on BBB transport investigations of endocytosis involving: transferrin and the targeting of the transferrin receptor; hormones; cytokines; cell penetrating peptides; microorganisms and toxins, and nanoparticles aimed at more effectively delivering drugs to the CNS.
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Affiliation(s)
- Mathew W Smith
- Pharmaceutical Cell Biology, Welsh School of Pharmacy, Cardiff University, Redwood Building, Cardiff CF10 3XF, UK
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38
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Abstract
Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality. Microbial invasion and traversal of the blood-brain barrier is a prerequisite for CNS infections. Pathogens can cross the blood-brain barrier transcellularly, paracellularly and/or in infected phagocytes (the so-called Trojan-horse mechanism). Consequently, pathogens can cause blood-brain barrier dysfunction, including increased permeability, pleocytosis and encephalopathy. A more complete understanding of the microbial-host interactions that are involved in microbial traversal of the blood-brain barrier and the associated barrier dysfunction should help to develop new strategies to prevent CNS infections.
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39
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Outer membrane protein A expression in Enterobacter sakazakii is required to induce microtubule condensation in human brain microvascular endothelial cells for invasion. Microb Pathog 2008; 45:181-91. [PMID: 18606523 DOI: 10.1016/j.micpath.2008.05.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 05/19/2008] [Accepted: 05/23/2008] [Indexed: 11/23/2022]
Abstract
Enterobacter sakazakii (ES) causes neonatal meningitis and necrotizing enterocolitis with case-fatality rates among infected infants ranging from 40 to 80%. Very little is known about the mechanisms by which these organisms cause disease. Here, we demonstrate that ES invades human brain microvascular endothelial cells (HBMEC) with higher frequency when compared with epithelial cells and endothelial cells from different origins. The entry of ES into HBMEC requires the expression of outer membrane protein A (OmpA), as the OmpA-deletion mutant was sevenfold less invasive than the wild type ES and the bacterium does not multiply inside HBMEC. Anti-OmpA antibodies generated against the OmpA of Escherichia coli K1, which also recognize the OmpA of ES, did not prevent the invasion of ES in HBMEC. ES invasion depends on microtubule condensation in HBMEC and is independent of actin filament reorganization. Both PI3-kinase and PKC-alpha were activated during ES entry into HBMEC between 15 min and 30 min of infection. Concomitantly, overexpression of dominant negative forms of PI3-kinase and PKC-alpha significantly inhibited the invasion of ES into HBMEC. In summary, ES invasion of HBMEC is dependent on the expression of OmpA similar to that of E. coli K1; however, the epitopes involved in the interaction with HBMEC appears to be different.
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40
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Magalashvili L, Lazarovich S, Pechatnikov I, Wexler HM, Nitzan Y. Cytokine release and expression induced by OmpA proteins from the Gram-negative anaerobes, Porphyromonas asaccharolytica and Bacteroides fragilis. ACTA ACUST UNITED AC 2008; 53:252-9. [PMID: 18503547 DOI: 10.1111/j.1574-695x.2008.00423.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OmpA proteins from Gram-negative anaerobes Porphyromonas asaccharolytica and Bacteroides fragilis induced release and expression of IL-1alpha, tumor necrosis factor (TNF)-alpha, IFN-gamma, IL-6, and IL-10 from murine splenocytes in vitro in a dose-dependent fashion. The release of the cytokines induced by B. fragilis Bf-OmpA was at much lower levels compared with P. asaccharolytica Omp-PA; Bf-OmpA did not induce release of IL-10. Omp-PA and Bf-OmpA were able to upregulate mRNA expression of the tested cytokines. The results obtained with refolded Bf-OmpA were similar to those with native Bf-OmpA. The data presented in this research demonstrate for the first time that Omps from anaerobic bacteria can induce the release of cytokines, suggesting that Omp-PA and Bf-OmpA may play important roles in the pathogenic processes of these bacteria.
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Affiliation(s)
- Lana Magalashvili
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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41
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Jung SY, Alsam S, Kim KS, Khan NA. Pathogen–pathogen interactions: a comparative study of Escherichia coli interactions with the clinical and environmental isolates of Acanthamoeba. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9754-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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42
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Kim YV, Pearce D, Kim KS. Ca(2+)/calmodulin-dependent invasion of microvascular endothelial cells of human brain by Escherichia coli K1. Cell Tissue Res 2008; 332:427-33. [PMID: 18379824 DOI: 10.1007/s00441-008-0598-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 02/04/2008] [Indexed: 12/24/2022]
Abstract
Escherichia coli K1 invasion of microvascular endothelial cells of human brain (HBMEC) is required for E. coli penetration into the central nervous system, but the microbial-host interactions that are involved in this invasion of HBMEC remain incompletely understood. We have previously shown that FimH, one of the E. coli determinants contributing to the binding to and invasion of HBMEC, induces Ca(2+) changes in HBMEC. In the present study, we have investigated in detail the role of cellular calcium signaling in the E. coli K1 invasion of HBMEC, the main constituents of the blood-brain barrier. Addition of the meningitis-causing E. coli K1 strain RS218 (O18:K1) to HBMEC results in transient increases of intracellular free Ca(2+). Inhibition of phospholipase C with U-73122 and the chelating of intracellular Ca(2+) by BAPTA/AM reduces bacterial invasion of HBMEC by approximately 50%. Blocking of transmembrane Ca(2+) fluxes by extracellular lanthanum ions also inhibits the E. coli invasion of HBMEC by approximately 50%. In addition, E. coli K1 invasion is significantly inhibited when HBMEC are pretreated by the calmodulin antagonists, trifluoperazine or calmidazolium, or by ML-7, a specific inhibitor of Ca(2+)/calmodulin-dependent myosin light-chain kinase. These findings indicate that host intracellular Ca(2+) signaling contributes in part to E. coli K1 invasion of HBMEC.
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Affiliation(s)
- Yuri V Kim
- Division of Pediatrics Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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43
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The hek outer membrane protein of Escherichia coli strain RS218 binds to proteoglycan and utilizes a single extracellular loop for adherence, invasion, and autoaggregation. Infect Immun 2007; 76:1135-42. [PMID: 18160475 DOI: 10.1128/iai.01327-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Escherichia coli is the principal gram-negative causative agent of sepsis and meningitis in neonates. The pathogenesis of meningitis due to E. coli K1 involves mucosal colonization, transcytosis of epithelial cells, survival in the bloodstream, and eventually invasion of the meninges. The last two aspects have been well characterized at a molecular level. Less is known about the early stages of pathogenesis, i.e., adhesion to and invasion of epithelial cells. We have previously reported that the Hek protein causes autoaggregation and can mediate adherence to and invasion of epithelial cells. Here, we report that Hek-mediated adherence is dependent on binding to glycosoaminoglycan, in particular, heparin. The ability to hemagglutinate, autoaggregate, adhere, and invade is contingent on a putative 25-amino-acid loop that is exposed to the outside of the bacterial cells.
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44
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Mohan Nair MK, Venkitanarayanan K. Role of bacterial OmpA and host cytoskeleton in the invasion of human intestinal epithelial cells by Enterobacter sakazakii. Pediatr Res 2007; 62:664-9. [PMID: 17957161 DOI: 10.1203/pdr.0b013e3181587864] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Enterobacter sakazakii is an emerging pathogen in neonates and infants. Interactions of E. sakazakii with intestinal epithelium could be vital in the pathogenesis of enteric infections and in its systemic dissemination. The present study investigated the interaction of E. sakazakii with human intestinal epithelial (INT407) cells and the role of bacterial outer membrane protein A (OmpA) and host cytoskeleton in these interactions. E. sakazakii invaded INT407 cells with moderate efficiency. An ompA mutant of E. sakazakii was significantly attenuated in its invasiveness, and complementation restored the invasive phenotype significantly. Drugs acting on host cell microfilaments (MF) and microtubules (MT) significantly inhibited bacterial invasion. Localization of both microfilaments (MF) and microtubules (MT) was observed in INT407 cells following E. sakazakii infection. The results suggest that E. sakazakii invasion of INT407 cells involves participation of both MF and MT and bacterial OmpA plays a critical role in invasion.
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45
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Petersen L, Bollback JP, Dimmic M, Hubisz M, Nielsen R. Genes under positive selection in Escherichia coli. Genome Res 2007; 17:1336-43. [PMID: 17675366 PMCID: PMC1950902 DOI: 10.1101/gr.6254707] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We used a comparative genomics approach to identify genes that are under positive selection in six strains of Escherichia coli and Shigella flexneri, including five strains that are human pathogens. We find that positive selection targets a wide range of different functions in the E. coli genome, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. Structural mapping of positively selected sites on trans-membrane beta barrel porins reveals that the residues under positive selection occur almost exclusively in the extracellular region of the proteins that are enriched with sites known to be targets of phages, colicins, or the host immune system. More surprisingly, we also find a number of other categories of genes that show very strong evidence for positive selection, such as the enigmatic rhs elements and transposases. Based on structural evidence, we hypothesize that the selection acting on transposases is related to the genomic conflict between transposable elements and the host genome.
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Affiliation(s)
- Lise Petersen
- Bioinformatics Centre, University of Copenhagen, Copenhagen DK-2200, Denmark.
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46
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Smith SGJ, Mahon V, Lambert MA, Fagan RP. A molecular Swiss army knife: OmpA structure, function and expression. FEMS Microbiol Lett 2007; 273:1-11. [PMID: 17559395 DOI: 10.1111/j.1574-6968.2007.00778.x] [Citation(s) in RCA: 291] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The OmpA outer membrane protein of Escherichia coli and other enterobacteria is a multifaceted protein. This protein is expressed to very high levels and ompA is tightly regulated at the posttranscriptional level. It can function as an adhesin and invasin, participate in biofilm formation, act as both an immune target and evasin, and serves as a receptor for several bacteriophages. Many of these properties are due to four short protein loops that emanate from the protein to the outside of the cell. Herein it is described how the structure of this protein relates to its many functions.
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Affiliation(s)
- Stephen G J Smith
- Department of Clinical Microbiology, Trinity College Dublin, St James's Hospital, Dublin, Ireland.
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Behling-Kelly E, McClenahan D, Kim KS, Czuprynski CJ. Viable "Haemophilus somnus" induces myosin light-chain kinase-dependent decrease in brain endothelial cell monolayer resistance. Infect Immun 2007; 75:4572-81. [PMID: 17591789 PMCID: PMC1951199 DOI: 10.1128/iai.00028-07] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
"Haemophilus somnus" causes thrombotic meningoencephalitis in cattle. Our laboratory has previously reported that H. somnus has the ability to adhere to, but not invade, bovine brain endothelial cells (BBEC) in vitro. The goal of this study was to determine if H. somnus alters brain endothelial cell monolayer integrity in vitro, in a manner that would be expected to contribute to inflammation of the central nervous system (CNS). Monolayer integrity was monitored by measuring transendothelial electrical resistance (TEER) and albumin flux. BBEC incubated with H. somnus underwent rapid cytoskeletal rearrangement, significant increases in albumin flux, and reductions in TEER. Decreased monolayer TEER was preceded by phosphorylation of the myosin regulatory light chain and was partially dependent on tumor necrosis factor alpha and myosin light-chain kinase but not interleukin-1beta. Neither heat-killed H. somnus, formalin-fixed H. somnus, nor purified lipooligosaccharide altered monolayer integrity within a 2-h incubation period, whereas conditioned medium from H. somnus-treated BBEC caused a modest reduction in TEER. The data from this study support the hypothesis that viable H. somnus alters integrity of the blood-brain barrier by promoting contraction of BBEC and increasing paracellular permeability of the CNS vasculature.
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Affiliation(s)
- E Behling-Kelly
- Department of Pathobiological Sciences, School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706, USA
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Zou Y, He L, Wu CH, Cao H, Xie ZH, Ouyang Y, Wang Y, Jong A, Huang SH. PSF is an IbeA-binding protein contributing to meningitic Escherichia coli K1 invasion of human brain microvascular endothelial cells. Med Microbiol Immunol 2007; 196:135-43. [PMID: 17318576 DOI: 10.1007/s00430-006-0034-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Indexed: 11/29/2022]
Abstract
During the development of Escherichia coli K1 meningitis, interaction between E. coli invasion protein IbeA and surface protein(s) on human brain microvascular endothelial cells (HBMEC) is required for invasion and IbeA-mediated signaling. Here, an IbeA-binding protein was identified as polypyrimidine tract-binding protein (PTB)-associated splicing factor (PSF). The specific binding was confirmed by ligand overlay assay. The cell surface-expressed PSF was verified by the confocal microscopy. Recombinant PSF blocked E. coli K1 invasion of HBMEC effectively. Overexpression of PSF in the lentivirus-transducted HBMEC significantly enhanced E. coli K1 invasion. These results suggest that IbeA interacts with PSF for the E. coli K1 invasion of HBMEC.
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Affiliation(s)
- Yanming Zou
- Saban Research Institute, Childrens Hospital Los Angeles, Los Angeles, CA 90027, USA
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Sahni SK. Endothelial cell infection and hemostasis. Thromb Res 2007; 119:531-49. [PMID: 16875715 DOI: 10.1016/j.thromres.2006.06.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 06/09/2006] [Accepted: 06/09/2006] [Indexed: 01/24/2023]
Abstract
As an important component of the vasculature, endothelial cell lining covers the inner surface of blood vessels and provides an active barrier interface between the vascular and perivascular compartments. In addition to maintaining vasomotor equilibrium and organ homeostasis and communicating with circulating blood cells, the vascular endothelium also serves as the preferred target for a number of infectious agents. This review article focuses on the roles of interactions between vascular endothelial cells and invading pathogens and resultant endothelial activation in the pathogenesis of important human diseases with viral and bacterial etiologies. In this perspective, the signal transduction events that regulate vascular inflammation and basis for endothelial cell tropism exhibited by certain specific viruses and pathogenic bacteria are also discussed.
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Affiliation(s)
- Sanjeev K Sahni
- Department of Medicine, Hematology-Oncology Unit, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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Nikulin J, Panzner U, Frosch M, Schubert-Unkmeir A. Intracellular survival and replication of Neisseria meningitidis in human brain microvascular endothelial cells. Int J Med Microbiol 2006; 296:553-8. [PMID: 17010667 DOI: 10.1016/j.ijmm.2006.06.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 06/14/2006] [Accepted: 06/14/2006] [Indexed: 11/30/2022] Open
Abstract
To cause meningitis the extracellular pathogen Neisseria meningitidis has to traverse the blood-cerebrospinal fluid (B-CSF) barrier. Postulating a transcellular passage, meningococci (MC) have been shown to adhere to and enter B-CSF barrier forming human brain microvascular endothelial cells (HBMEC). Furthermore, electron microscopy studies demonstrated that intracellular MC reside within membrane-bound compartments, both solitary and in groups. To investigate the ability of MC to survive and replicate intracellularly, prolonged gentamicin protection assays were performed. Encapsulated bacteria were found to survive and, after an initial delay, to replicate within HBMEC, whereas the number of intracellular capsule-deficient mutants decreased continuously. This strongly suggests that the capsule plays a pivotal role in the intracellular survival of MC. Further investigations were initiated to characterise the membrane-bound compartment, the Neisseria-containing vacuole (NCV). Immunfluorescence microscopy studies showed that NCVs interact with the endocytic pathway acquiring the early endosomal marker protein, transferrin receptor (TfR), and the late endosomal/lysosomal marker protein Lamp-1.
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Affiliation(s)
- Joanna Nikulin
- Institute of Hygiene and Microbiology, University of Wuerzburg, Josef-Schneider-Str. 2/E1, D-97080 Wuerzburg, Germany
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