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Walter FR, Santa-Maria AR, Mészáros M, Veszelka S, Dér A, Deli MA. Surface charge, glycocalyx, and blood-brain barrier function. Tissue Barriers 2021; 9:1904773. [PMID: 34003072 DOI: 10.1080/21688370.2021.1904773] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The negative surface charge of brain microvessel endothelial cells is derived from the special composition of their membrane lipids and the thick endothelial surface glycocalyx. They are important elements of the unique defense systems of the blood-brain barrier. The tissue-specific properties, components, function and charge of the brain endothelial glycocalyx have only been studied in detail in the past 15 years. This review highlights the importance of the negative surface charge in the permeability of macromolecules and nanoparticles as well as in drug interactions. We discuss surface charge and glycoxalyx changes in pathologies related to the brain microvasculature and protective measures against glycocalyx shedding and damage. We present biophysical techniques, including a microfluidic chip device, to measure surface charge of living brain endothelial cells and imaging methods for visualization of surface charge and glycocalyx.
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Affiliation(s)
- Fruzsina R Walter
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Ana R Santa-Maria
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Mária Mészáros
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Szilvia Veszelka
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - András Dér
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Mária A Deli
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
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Fu P, Shaaya M, Harijith A, Jacobson JR, Karginov A, Natarajan V. Sphingolipids Signaling in Lamellipodia Formation and Enhancement of Endothelial Barrier Function. CURRENT TOPICS IN MEMBRANES 2018; 82:1-31. [PMID: 30360778 DOI: 10.1016/bs.ctm.2018.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sphingolipids, first described in the brain in 1884, are important structural components of biological membranes of all eukaryotic cells. In recent years, several lines of evidence support the critical role of sphingolipids such as sphingosine, sphingosine-1-phosphate (S1P), and ceramide as anti- or pro-inflammatory bioactive lipid mediators in a variety of human pathologies including pulmonary and vascular disorders. Among the sphingolipids, S1P is a naturally occurring agonist that exhibits potent barrier enhancing property in the endothelium by signaling via G protein-coupled S1P1 receptor. S1P, S1P analogs, and other barrier enhancing agents such as HGF, oxidized phospholipids, and statins also utilize the S1P/S1P1 signaling pathway to generate membrane protrusions or lamellipodia, which have been implicated in resealing of endothelial gaps and maintenance of barrier integrity. A better understanding of sphingolipids mediated regulation of lamellipodia formation and barrier enhancement of the endothelium will be critical for the development of sphingolipid-based therapies to alleviate pulmonary disorders such as sepsis-, radiation-, and mechanical ventilation-induced acute lung injury.
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Affiliation(s)
- Panfeng Fu
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Mark Shaaya
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Anantha Harijith
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL, United States
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Andrei Karginov
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Viswanathan Natarajan
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States; Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States.
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3
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O'Toole D, Hunter R, Allen T, Zekarias B, Lehmann J, Kim KS, Grab D, Corbeil LB. Effect of Histophilus somni on Heart and Brain Microvascular Endothelial Cells. Vet Pathol 2017; 54:629-639. [PMID: 28178428 DOI: 10.1177/0300985817691581] [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: 01/01/2023]
Abstract
Histophilus somni is a pathogenic gram-negative bacterium responsible for pneumonia and septicemia in cattle. Sequelae include infectious thrombotic meningoencephalitis (ITME), myocarditis, arthritis, and abortion. These syndromes are associated with widespread vasculitis and thrombosis, implicating a role for endothelium in pathogenesis. Histopathologic and immunohistochemical investigation of 10 natural cases of bovine H. somni myocarditis and 1 case of ITME revealed intravascular H. somni in large biofilm-like aggregates adherent to the luminal surface of microvascular endothelium. Ultrastructurally, bacterial communities were extracellular and closely associated with degenerating or contracted endothelial cells. Histophilus somni was identified by bacterial culture and/or immunohistochemistry. Western blots of the bacterial isolates revealed that they expressed the immunodominant protective 40 kDa OMP and immunoglobulin-binding protein A (IbpA) antigens. The latter is a large surface antigen and shed fibrillar antigen with multiple domains. The cytotoxic DR2Fic domain of IbpA was conserved as demonstrated by polymerase chain reaction. Treatment of endothelial cells in vitro with IbpA in crude culture supernatants or purified recombinant GST-IbpA DR2Fic (rDR2) cytotoxin induced retraction of cultured bovine brain microvascular endothelial cells. By contrast, no retraction of bovine endothelium was induced by mutant rDR2H/A with an inactive Fic motif or by a GST control, indicating that the cytotoxic DR2Fic motif plays an important role in endothelial cell retraction in vasculitis. The formation of biofilm-like aggregates by H. somni on bovine microvascular endothelium may be fundamental to its pathogenesis in heart and brain.
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Affiliation(s)
- D O'Toole
- 1 Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, WY, USA
| | - R Hunter
- 2 Hunter Cattle Company LLC, Wheatland, WY, USA
| | - T Allen
- 1 Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, WY, USA.,3 Current: Advantage Veterinary, Nampa, ID, USA
| | - B Zekarias
- 4 Department of Pathology, University of California, San Diego, CA, USA.,5 Current: Ceva-Biommune, Lenexa, KS, USA
| | - J Lehmann
- 5 Current: Ceva-Biommune, Lenexa, KS, USA.,6 Current: BioLegend San Diego, CA, USA
| | - K S Kim
- 7 School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - D Grab
- 7 School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - L B Corbeil
- 4 Department of Pathology, University of California, San Diego, CA, USA
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Abstract
Histophilus somni is responsible for sporadic disease worldwide in cattle and, to a lesser extent, in small ruminants, bighorn sheep (Ovis canadensis), and North American bison (Bison bison). The importance of H. somni diseases can be attributed to improved clinical and laboratory recognition, combined with the growth in intensive management practices for cattle. Although outbreaks of bovine histophilosis can occur year-round, in northern and southern hemispheres, it is most frequent in late fall and early winter. Weather, stress, dietary changes, and comingling of cattle are likely to be major triggers for outbreaks. The most frequent clinical expressions of histophilosis include undifferentiated fever, fibrinosuppurative pneumonia, encephalitis-leptomeningitis, necrotizing myocarditis, and diffuse pleuritis. Neurological disease occurs either as thrombotic meningoencephalitis (TME) or as suppurative meningitis with ventriculitis. Acute myocarditis is characteristically necrotizing and generally involves one or both papillary muscles in the left ventricular myocardium. Biofilm-like aggregates of bacteria occur in capillaries and veins in myocardium, in the central nervous system, and on endocardial surfaces. H. somni is a component of bovine respiratory disease (BRD) complex. In our experience, it is most commonly diagnosed in subacute-to-chronic polymicrobial pulmonary infections in combination with Mannheimia haemolytica, Trueperella pyogenes, Pasteurella multocida, or Mycoplasma bovis. Other, less common forms of H. somni disease present as polyarthritis/tenosynovitis, abortion with placentitis and fetal septicemia, epididymitis-orchitis, and ocular infections. It is likely that H. somni is under-recognized clinically and diagnostically. Most state and provincial laboratories in North America rely on bacterial isolation to confirm infection. The use of more sensitive detection methods on field cases of histophilosis will help resolve the pathogenesis of H. somni in natural outbreaks, and whether the disease is as common elsewhere as it is in Canada.
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Szenci O, Sassi G, Fodor L, Molnár L, Szelényi Z, Tibold J, Mádl I, Egyed L. Co-infection with Bovine Herpesvirus 4 and Histophilus somni Significantly Extends the Service Period in Dairy Cattle with Purulent Vaginal Discharge. Reprod Domest Anim 2015; 51:143-9. [PMID: 26690881 DOI: 10.1111/rda.12658] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/17/2015] [Indexed: 11/29/2022]
Abstract
The aim of the study was to investigate the effect of Bovine Herpesvirus 4 (BoHV-4) and Histophilus (H.) somni on fertility rate of cows in a Hungarian Holstein-Friesian dairy herd with purulent vaginal discharge (PVD). Non-pregnant cows (n = 188) with mature corpus luteum were treated with cloprostenol and 3 days later if they did not show oestrus, were examined by rectal palpation. Animals showing PVD (n = 60/31.9%/) and 14 controls with normal vaginal discharge (Score 0) were randomly selected and further examined by ultrasonography and blood samples were collected for detecting BoHV-4 DNA and transcervical guarded swabs were collected from the uterus for bacteriological examination. Although the majority of the examined animals were infected with BoHV-4 and H. somni including the control animals as well, in group of animals with PVD score 3, fewer animals became pregnant and the duration between the first treatment to pregnancy was significantly extended. Based on these clinical and comparative data, our results confirm that these two microorganisms together may impair important reproductive parameters which may cause large economic losses to dairy farms.
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Affiliation(s)
- O Szenci
- MTA-SZIE Large Animal Clinical Research Group, Üllő-Dóra major, Hungary.,Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University, Üllő-Dóra major, Hungary
| | - G Sassi
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University, Üllő-Dóra major, Hungary
| | - L Fodor
- Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science, Szent István University, Budapest, Hungary
| | - L Molnár
- Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University, Üllő-Dóra major, Hungary
| | - Z Szelényi
- MTA-SZIE Large Animal Clinical Research Group, Üllő-Dóra major, Hungary.,Department and Clinic for Production Animals, Faculty of Veterinary Science, Szent István University, Üllő-Dóra major, Hungary
| | | | - I Mádl
- Agroproduct Zrt, Pápa, Hungary
| | - L Egyed
- Agricultural Research Center, Veterinary Medical Research Institute, Hungarian Academy of Sciences, Budapest, Hungary
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6
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The MSHA pilus of Vibrio parahaemolyticus has lectin functionality and enables TTSS-mediated pathogenicity. Int J Med Microbiol 2013; 303:563-73. [DOI: 10.1016/j.ijmm.2013.07.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/24/2013] [Accepted: 07/29/2013] [Indexed: 01/15/2023] Open
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7
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Hellenbrand KM, Forsythe KM, Rivera-Rivas JJ, Czuprynski CJ, Aulik NA. Histophilus somni causes extracellular trap formation by bovine neutrophils and macrophages. Microb Pathog 2012; 54:67-75. [PMID: 23022668 PMCID: PMC7125803 DOI: 10.1016/j.micpath.2012.09.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/17/2012] [Accepted: 09/19/2012] [Indexed: 12/17/2022]
Abstract
Histophilus somni (formerly Haemophilus somnus) is a Gram-negative pleomorphic coccobacillus that causes respiratory, reproductive, cardiac and neuronal diseases in cattle. H. somni is a member of the bovine respiratory disease complex that causes severe bronchopneumonia in cattle. Previously, it has been reported that bovine neutrophils and macrophages have limited ability to phagocytose and kill H. somni. Recently, it was discovered that bovine neutrophils and macrophages produce extracellular traps in response to Mannheimia haemolytica, another member of the bovine respiratory disease complex. In this study, we demonstrate that H. somni also causes extracellular trap production by bovine neutrophils in a dose- and time-dependent manner, which did not coincide with the release of lactate dehydrogenase, a marker for necrosis. Neutrophil extracellular traps were produced in response to outer membrane vesicles, but not lipooligosacchride alone. Using scanning electron microscopy and confocal microscopy, we observed H. somni cells trapped within a web-like structure. Further analyses demonstrated that bovine neutrophils trapped and killed H. somni in a DNA-dependent manner. Treatment of DNA extracellular traps with DNase I freed H. somni cells and diminished bacterial death. Treatment of bovine monocyte-derived macrophages with H. somni cells also caused macrophage extracellular trap formation. These findings suggest that extracellular traps may play a role in the host response to H. somni infection in cattle.
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Affiliation(s)
- Katrina M. Hellenbrand
- Department of Pathobiological Sciences, University of Wisconsin – Madison, Madison, WI 53706, USA
| | | | - Jose J. Rivera-Rivas
- Department of Pathobiological Sciences, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Charles J. Czuprynski
- Department of Pathobiological Sciences, University of Wisconsin – Madison, Madison, WI 53706, USA
- Food Research Institute, University of Wisconsin – Madison, Madison, WI 53706, USA
- Corresponding author. Department of Pathobiological Sciences, 2015, Linden Drive, West, Madison, WI 53706, USA. Tel./fax: +1 608 262 8102.
| | - Nicole A. Aulik
- Department of Pathobiological Sciences, University of Wisconsin – Madison, Madison, WI 53706, USA
- Biology Department, Winona State University, Winona, MN 55987, USA
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8
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Elswaifi SF, Scarratt WK, Inzana TJ. The role of lipooligosaccharide phosphorylcholine in colonization and pathogenesis of Histophilus somni in cattle. Vet Res 2012; 43:49. [PMID: 22676226 PMCID: PMC3406970 DOI: 10.1186/1297-9716-43-49] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 06/07/2012] [Indexed: 11/17/2022] Open
Abstract
Histophilus somni is a Gram-negative bacterium and member of the Pasteurellaceae that is responsible for respiratory disease and other systemic infections in cattle. One of the bacterium’s virulence factors is antigenic phase variation of its lipooligosaccharide (LOS). LOS antigenic variation may occur through variation in composition or structure of glycoses or their substitutions, such as phosphorylcholine (ChoP). However, the role of ChoP in the pathogenesis of H. somni disease has not been established. In Haemophilus influenzae ChoP on the LOS binds to platelet activating factor on epithelial cells, promoting bacterial colonization of the host upper respiratory tract. However, ChoP is not expressed in the blood as it also binds C-reactive protein, resulting in complement activation and killing of the bacteria. In order to simulate the susceptibility of calves with suppressed immunity due to stress or previous infection, calves were challenged with bovine herpes virus-1 or dexamethazone 3 days prior to challenge with H. somni. Following challenge, expression of ChoP on the LOS of 2 different H. somni strains was associated with colonization of the upper respiratory tract. In contrast, lack of ChoP expression was associated with bacteria recovered from systemic sites. Histopathology of cardiac tissue from myocarditis revealed lesions containing bacterial clusters that appeared similar to a biofilm. Furthermore, some respiratory cultures contained substantial numbers of Pasteurella multocida, which were not present on preculture screens. Subsequent biofilm experiments have shown that H. somni and P. multocida grow equally well together in a biofilm, suggesting a commensal relationship may exist between the two species. Our results also showed that ChoP contributed to, but was not required for, adhesion to respiratory epithelial cells. In conclusion, expression of ChoP on H. somni LOS contributed to colonization of the bacteria to the host upper respiratory tract, but phase variable loss of ChoP expression may help the bacteria survive systemically.
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Affiliation(s)
- Shaadi F Elswaifi
- Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA.
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9
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Sandal I, Inzana TJ, Molinaro A, De Castro C, Shao JQ, Apicella MA, Cox AD, St Michael F, Berg G. Identification, structure, and characterization of an exopolysaccharide produced by Histophilus somni during biofilm formation. BMC Microbiol 2011; 11:186. [PMID: 21854629 PMCID: PMC3224263 DOI: 10.1186/1471-2180-11-186] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/19/2011] [Indexed: 01/15/2023] Open
Abstract
Background Histophilus somni, a gram-negative coccobacillus, is an obligate inhabitant of bovine and ovine mucosal surfaces, and an opportunistic pathogen responsible for respiratory disease and other systemic infections in cattle and sheep. Capsules are important virulence factors for many pathogenic bacteria, but a capsule has not been identified on H. somni. However, H. somni does form a biofilm in vitro and in vivo, and the biofilm matrix of most bacteria consists of a polysaccharide. Results Following incubation of H. somni under growth-restricting stress conditions, such as during anaerobiosis, stationary phase, or in hypertonic salt, a polysaccharide could be isolated from washed cells or culture supernatant. The polysaccharide was present in large amounts in broth culture sediment after H. somni was grown under low oxygen tension for 4-5 days (conditions favorable to biofilm formation), but not from planktonic cells during log phase growth. Immuno-transmission electron microscopy showed that the polysaccharide was not closely associated with the cell surface, and was of heterogeneous high molecular size by gel electrophoresis, indicating it was an exopolysaccharide (EPS). The EPS was a branched mannose polymer containing some galactose, as determined by structural analysis. The mannose-specific Moringa M lectin and antibodies to the EPS bound to the biofilm matrix, demonstrating that the EPS was a component of the biofilm. The addition of N-acetylneuraminic acid to the growth medium resulted in sialylation of the EPS, and increased biofilm formation. Real-time quantitative reverse transcription-polymerase chain reaction analyses indicated that genes previously identified in a putative polysaccharide locus were upregulated when the bacteria were grown under conditions favorable to a biofilm, compared to planktonic cells. Conclusions H. somni is capable of producing a branching, mannose-galactose EPS polymer under growth conditions favorable to the biofilm phase of growth, and the EPS is a component of the biofilm matrix. The EPS can be sialylated in strains with sialyltransferase activity, resulting in enhanced density of the biofilm, and suggesting that EPS and biofilm formation may be important to persistence in the bovine host. The EPS may be critical to virulence if the biofilm state is required for H. somni to persist in systemic sites.
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Affiliation(s)
- Indra Sandal
- Center for Molecular Medicine and Infectious Diseases, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
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Glycosaminoglycan binding facilitates entry of a bacterial pathogen into central nervous systems. PLoS Pathog 2011; 7:e1002082. [PMID: 21731486 PMCID: PMC3121876 DOI: 10.1371/journal.ppat.1002082] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 04/11/2011] [Indexed: 11/26/2022] Open
Abstract
Certain microbes invade brain microvascular endothelial cells (BMECs) to breach the blood-brain barrier (BBB) and establish central nervous system (CNS) infection. Here we use the leading meningitis pathogen group B Streptococcus (GBS) together with insect and mammalian infection models to probe a potential role of glycosaminoglycan (GAG) interactions in the pathogenesis of CNS entry. Site-directed mutagenesis of a GAG-binding domain of the surface GBS alpha C protein impeded GBS penetration of the Drosophila BBB in vivo and diminished GBS adherence to and invasion of human BMECs in vitro. Conversely, genetic impairment of GAG expression in flies or mice reduced GBS dissemination into the brain. These complementary approaches identify a role for bacterial-GAG interactions in the pathogenesis of CNS infection. Our results also highlight how the simpler yet genetically conserved Drosophila GAG pathways can provide a model organism to screen candidate molecules that can interrupt pathogen-GAG interactions for future therapeutic applications. Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of meningitis in human newborn infants. The bacterial and host factors that allow this pathogen to cross the blood-brain barrier (BBB) and cause central nervous system (CNS) infection are not well understood. Here we demonstrate that GBS expresses a specific protein on its surface that can bind to sugar molecules known as glycosaminoglycans (GAGs) on the surface of brain capillary cells, initiating infection of the BBB. Fruit flies or mice genetically engineered to have reduced GAGs showed decreased dissemination of GBS into the brain tissues following experimental infection. Our results identify a role for bacterial-GAG interactions in the pathogenesis of newborn meningitis and highlight how the simpler yet genetically conserved fruit fly GAG biosynthetic pathways make the fruit fly a good model organism to screen candidate molecules that can interrupt pathogen-GAG interactions for future therapeutic applications.
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Zhou Q, Chen H, Qu M, Wang Q, Yang L, Xie L. Development of a novel ex vivo model of corneal fungal adherence. Graefes Arch Clin Exp Ophthalmol 2010; 249:693-700. [PMID: 21184093 DOI: 10.1007/s00417-010-1601-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 11/22/2010] [Accepted: 12/02/2010] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To construct a suitable ex vivo model for the research of molecular mechanisms and the pharmacological screening of fungal adherence on the corneal surface. MATERIALS AND METHODS Mouse eyes were divided into three groups as follows: a control group with normal corneal epithelium, a group with corneal epithelium that was needle-scarified, and a group with corneal epithelium that was completely debrided. All 96 corneas were placed in organ culture and inoculated with 5 μl spore suspensions of Candida albicans at 10⁹, 10⁸, or 10⁷ colony-forming units (CFU)/ml and incubated for 0, 30, 60, or 120 min. The corneas were homogenated and diluted for quantification by counting the CFU. The effects of amphotericin B or chondroitin sulfate on the adherence of the fungal spores were evaluated with the ex vivo organ culture model and were also compared with the human corneal epithelium monolayer model in vitro. RESULTS Compared with the normal corneas with intact epithelium, the corneas with scarified and debrided epithelium adhered more spores for above two and four folds. The spore adhesion on the corneal surface was in an inoculation concentration- and incubation time-dependent manner. Moreover, both amphotericin B and chondroitin sulfate inhibited the adhesion of C. albicans spores on the corneal surface, but the inhibitory rates were different between the ex vivo corneal organ culture model and the in vitro corneal epithelium monolayer model. CONCLUSIONS The corneal organ culture was a suitable ex vivo model for the research of fungal adhesion mechanisms and drug screening.
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Affiliation(s)
- Qingjun Zhou
- Shandong Provincial Key Lab of Ophthalmology, Shandong Eye Institute, Qingdao, 266071, China
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12
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Abstract
AbstractBovine respiratory disease (BRD) involves complex interactions amongst viral and bacterial pathogens that can lead to intense pulmonary inflammation (fibrinous pleuropneumonia). Viral infection greatly increases the susceptibility of cattle to secondary infection of the lung with bacterial pathogens likeMannheimia haemolyticaandHistophilus somni. The underlying reason for this viral/bacterial synergism, and the manner in which cattle respond to the virulence strategies of the bacterial pathogens, is incompletely understood. Bovine herpesvirus type 1 (BHV-1) infection of bronchial epithelial cellsin vitroenhances the binding ofM. haemolyticaand triggers release of inflammatory mediators that attract and enhance binding of neutrophils. An exotoxin (leukotoxin) released fromM. haemolyticafurther stimulates release of inflammatory mediators and causes leukocyte death. Cattle infected withH. somnifrequently display vasculitis. Exposure of bovine endothelial cells toH. somniior its lipooligosaccharide (LOS) increases endothelium permeability, and makes the surface of the endothelial cells pro-coagulant. These processes are amplified in the presence of platelets. The above findings demonstrate that bovine respiratory pathogens (BHV-1,M. haemolyticaandH. somni) interact with leukocytes and other cells (epithelial and endothelial cells) leading to the inflammation that characterizes BRD.
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13
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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: 6.8] [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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14
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Tiwari R, Sullivan J, Czuprynski C. PECAM-1 is involved in neutrophil transmigration across Histophilus somni treated bovine brain endothelial cells. Microb Pathog 2009; 47:164-70. [DOI: 10.1016/j.micpath.2009.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/26/2009] [Accepted: 06/04/2009] [Indexed: 11/17/2022]
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Hoshinoo K, Sasaki K, Tanaka A, Corbeil LB, Tagawa Y. Virulence attributes of Histophilus somni with a deletion mutation in the ibpA gene. Microb Pathog 2009; 46:273-82. [DOI: 10.1016/j.micpath.2009.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2008] [Revised: 02/23/2009] [Accepted: 02/25/2009] [Indexed: 01/22/2023]
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16
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Sava IG, Zhang F, Toma I, Theilacker C, Li B, Baumert TF, Holst O, Linhardt RJ, Huebner J. Novel interactions of glycosaminoglycans and bacterial glycolipids mediate binding of enterococci to human cells. J Biol Chem 2009; 284:18194-201. [PMID: 19395379 DOI: 10.1074/jbc.m901460200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Enterococcus faecalis is among the most important nosocomial pathogens. The intestinal mucosa is considered to be the main site used by these bacteria for entrance and dissemination. A better understanding of the mechanisms involved in colonization and invasion of enterococci may help to devise methods to prevent infections in hospitalized patients. Glycosaminoglycans, which are present on the surface of all eukaryotic cells, were investigated with regard to their role as host receptors for adhesion of E. faecalis. Competitive binding assays, enzymatic digestion, and reduction of the sulfation of the glycosaminoglycan chains indicated that heparin and heparan sulfate, but not chondroitin sulfate B, played important roles in adhesion of E. faecalis 12030 to Caco2 cells. By using proteinases and carbohydrate oxidation by sodium meta-periodate to modify the bacterial surface, it could be demonstrated that a sugar-containing molecule rather than a protein is the bacterial ligand mediating adhesion to eukaryotic cells. Preincubation of Caco2 cells with the enterococcal glycolipid diglucosyldiacylglycerol but not other carbohydrate cell wall components inhibited bacterial binding. These results may indicate that heparin and/or heparan sulfate on host epithelial cells and diglucosyldiacylglycerol, either itself or as a partial structure of lipoteichoic acid, are involved in enterococcal adhesion to colonic epithelia, the first step in translocation from the intestinal tract.
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Affiliation(s)
- Irina G Sava
- Division of Infectious Diseases, University Medical Center Freiburg, 79106 Freiburg, Germany
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Abstract
Histophilus somni (Haemophilus somnus) is one of the key bacterial pathogens involved in the multifactorial etiology of the Bovine Respiratory Disease Complex. This Gram negative pleomorphic rod also causes bovine septicemia, thrombotic meningencephalitis, myocarditis, arthritis, abortion and infertility, as well as disease in sheep, bison and bighorn sheep. Virulence factors include lipooligosaccharide, immunoglobulin binding proteins (as a surface fibrillar network), a major outer membrane protein (MOMP), other outer membrane proteins (OMPs) and exopolysaccharide. Histamine production, biofilm formation and quorum sensing may also contribute to pathogenesis. Antibodies are very important in protection as shown in passive protection studies. The lack of long-term survival of the organism in macrophages, unlike facultative intracellular bacteria, also suggests that antibodies should be critical in protection. Of the immunoglobulin classes, IgG2 antibodies are most implicated in protection and IgE antibodies in immunopathogenesis. The immunodominant antigen recognized by IgE is the MOMP and by IgG2 is a 40 kDa OMP. Pathogenetic synergy of bovine respiratory syncytial virus (BRSV) and H. somni in calves can be attributed, in part at least, to the higher IgE anti-MOMP antibody responses in dually infected calves. Other antigens are probably involved in stimulating host defense or immunopathology as well.
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PLATELET ACTIVATION BY HISTOPHILUS SOMNI AND ITS LIPOOLIGOSACCHARIDE INDUCES ENDOTHELIAL CELL PROINFLAMMATORY RESPONSES AND PLATELET INTERNALIZATION. Shock 2008. [DOI: 10.1097/shk.0b013e318070c49e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kuckleburg CJ, McClenahan DJ, Czuprynski CJ. Platelet activation by Histophilus somni and its lipooligosaccharide induces endothelial cell proinflammatory responses and platelet internalization. Shock 2008; 29:189-196. [PMID: 18386389 PMCID: PMC2405899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Histophilus somni is a gram-negative coccobacillus that causes respiratory and reproductive disease in cattle. The hallmark of systemic H. somni infection is diffuse vascular inflammation that can lead to an acute central nervous system disease known as thrombotic meningoencephalitis. Previously, we demonstrated that H. somni and its lipooligosaccharide (LOS) activate bovine platelets, leading to expression of P selectin, CD40L, and FasL. Because activated platelets have been reported to induce endothelial cell cytokine production and adhesion molecule expression, we sought to determine if bovine platelets induce proinflammatory and procoagulative changes in bovine pulmonary artery endothelial cells. Endothelial cells were incubated with platelets activated with adenosine diphosphate, H. somni, or H. somni LOS. Incubation with activated bovine platelets significantly increased expression of in adhesion molecules (intercellular adhesion molecule 1, E selectin) and tissue factor, as measured by flow cytometry, real-time polymerase chain reaction, and Western blot analysis. Activated platelets also up-regulated expression of endothelial cell IL-1beta, monocyte chemoattractant protein 1, and macrophage inflammatory protein 1alpha as determined by real-time polymerase chain reaction and an IL-1beta enzyme-linked immunosorbent assay. An interesting and surprising finding was that bovine platelets activated by H. somni or its LOS were internalized by bovine endothelial cells as visualized by transmission electron microscopy. This internalization seemed to correlate with endothelial cell activation and morphological changes indicative of cell stress. These findings suggest that activated platelets might play a role in promoting vascular inflammation during H. somni infection.
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Affiliation(s)
- Christopher J. Kuckleburg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI
| | - Dave J. McClenahan
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI
| | - Charles J. Czuprynski
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI
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C-terminal repeats of Clostridium difficile toxin A induce production of chemokine and adhesion molecules in endothelial cells and promote migration of leukocytes. Infect Immun 2007; 76:1170-8. [PMID: 18160482 DOI: 10.1128/iai.01340-07] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The C-terminal repeating sequences of Clostridium difficile toxin A (designated ARU) are homologous to the carbohydrate-binding domain of streptococcal glucosyltransferases (GTFs) that were recently identified as potent modulins. To test the hypothesis that ARU might exert a similar biological activity on endothelial cells, recombinant ARU (rARU), which was noncytotoxic to cell cultures, was analyzed using human umbilical vein endothelial cells. The rARU could bind directly to endothelial cells in a serum- and calcium-dependent manner and induce the production of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein 1 in a dose-dependent manner. An oligosaccharide binding assay indicated that rARU, but not GTFC, binds preferentially to Lewis antigens and 3'HSO3-containing oligosaccharides. Binding of rARU to human endothelial or intestinal cells correlated directly with the expression of Lewis Y antigen. Bound rARU directly activated mitogen-activated protein kinases and the NF-kappaB signaling pathway in endothelial cells to release biologically active chemokines and adhesion molecules that promoted migration in a transwell assay and the adherence of polymorphonuclear and mononuclear cells to the endothelial cells. These results suggest that ARU may bind to multiple carbohydrate motifs to exert its biological activity on human endothelial cells.
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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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