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Chen H, Zhou M, Zeng Y, Miao T, Luo H, Tong Y, Zhao M, Mu R, Gu J, Yang S, Han L. Biomimetic Lipopolysaccharide-Free Bacterial Outer Membrane-Functionalized Nanoparticles for Brain-Targeted Drug Delivery. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105854. [PMID: 35355446 PMCID: PMC9165477 DOI: 10.1002/advs.202105854] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/21/2022] [Indexed: 05/04/2023]
Abstract
The blood-brain barrier (BBB) severely blocks the intracranial accumulation of most systemic drugs. Inspired by the contribution of the bacterial outer membrane to Escherichia coli K1 (EC-K1) binding to and invasion of BBB endothelial cells in bacterial meningitis, utilization of the BBB invasion ability of the EC-K1 outer membrane for brain-targeted drug delivery and construction of a biomimetic self-assembled nanoparticle with a surface featuring a lipopolysaccharide-free EC-K1 outer membrane are proposed. BBB penetration of biomimetic nanoparticles is demonstrated to occur through the transcellular vesicle transport pathway, which is at least partially dependent on internalization, endosomal escape, and transcytosis mediated by the interactions between outer membrane protein A and gp96 on BBB endothelial cells. This biomimetic nanoengineering strategy endows the loaded drugs with prolonged circulation, intracranial interstitial distribution, and extremely high biocompatibility. Based on the critical roles of gp96 in cancer biology, this strategy reveals enormous potential for delivering therapeutics to treat gp96-overexpressing intracranial malignancies.
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Affiliation(s)
- Haiyan Chen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Mengyuan Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Yuteng Zeng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Tongtong Miao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Haoyuan Luo
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Yang Tong
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Mei Zhao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Rui Mu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Jiang Gu
- National Engineering Research Centre of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of PharmacyThird Military Medical UniversityChongqing400038P. R. China
| | - Shudi Yang
- Suzhou Polytechnic Institute of AgricultureSuzhou215008P. R. China
| | - Liang Han
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, College of Pharmaceutical SciencesSoochow UniversitySuzhouJiangsu215123P. R. China
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Development of a chitosan-modified PLGA nanoparticle vaccine for protection against Escherichia coli K1 caused meningitis in mice. J Nanobiotechnology 2021; 19:69. [PMID: 33673858 PMCID: PMC7934409 DOI: 10.1186/s12951-021-00812-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/20/2021] [Indexed: 12/31/2022] Open
Abstract
Background Escherichia coli K1 (E. coli K1) caused neonatal meningitis remains a problem, which rises the urgent need for an effective vaccine. Previously, we rationally designed and produced the recombinant protein OmpAVac (Vo), which elicited protective immunity against E. coli K1 infection. However, Vo has limited stability, which hinders its future industrial application. Method Chitosan-modified poly (lactic-co-glycolic acid) (PLGA) nanoparticles were prepared and used as carried for the recombinant Vo. And the safety, stability and immunogenicity of Vo delivered by chitosan-modified PLGA nanoparticles were tested in vitro and in a mouse model of bacteremia. Results We successfully generated chitosan-modified PLGA nanoparticles for the delivery of recombinant Vo (VoNP). In addition, we found that a freeze-drying procedure increases the stability of the VoNPs without changing the shape, size distribution and encapsulation of the Vo protein. Unlike aluminum adjuvant, the nanoparticles that delivered Vo were immunoprotective in mice even after storage for as long as 180 days. Conclusions We identified an effective strategy to improve the stability of Vo to maintain its immunogenicity, which will contribute to the future development of vaccines against E. coli K1.![]()
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Bosák J, Hrala M, Micenková L, Šmajs D. Non-antibiotic antibacterial peptides and proteins of Escherichia coli: efficacy and potency of bacteriocins. Expert Rev Anti Infect Ther 2020; 19:309-322. [PMID: 32856960 DOI: 10.1080/14787210.2020.1816824] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION The emergence and spread of antibiotic resistance among pathogenic bacteria drives the search for alternative antimicrobial therapies. Bacteriocins represent a potential alternative to antibiotic treatment. In contrast to antibiotics, bacteriocins are peptides or proteins that have relatively narrow spectra of antibacterial activities and are produced by a wide range of bacterial species. Bacteriocins of Escherichia coli are historically classified as microcins and colicins, and, until now, more than 30 different bacteriocin types have been identified and characterized. AREAS COVERED We performed bibliographical searches of online databases to review the literature regarding bacteriocins produced by E. coli with respect to their occurrence, bacteriocin role in bacterial colonization and pathogenicity, and application of their antimicrobial effect. EXPERT OPINION The potential use of bacteriocins for applications in human and animal medicine and the food industry includes (i) the use of bacteriocin-producing probiotic strains, (ii) recombinant production in plants and application in food, and (iii) application of purified bacteriocins.
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Affiliation(s)
- Juraj Bosák
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Matěj Hrala
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lenka Micenková
- Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Pascoal C, Francisco R, Ferro T, Dos Reis Ferreira V, Jaeken J, Videira PA. CDG and immune response: From bedside to bench and back. J Inherit Metab Dis 2020; 43:90-124. [PMID: 31095764 DOI: 10.1002/jimd.12126] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/13/2019] [Accepted: 05/15/2019] [Indexed: 12/20/2022]
Abstract
Glycosylation is an essential biological process that adds structural and functional diversity to cells and molecules, participating in physiological processes such as immunity. The immune response is driven and modulated by protein-attached glycans that mediate cell-cell interactions, pathogen recognition and cell activation. Therefore, abnormal glycosylation can be associated with deranged immune responses. Within human diseases presenting immunological defects are congenital disorders of glycosylation (CDG), a family of around 130 rare and complex genetic diseases. In this review, we have identified 23 CDG with immunological involvement, characterized by an increased propensity to-often life-threatening-infection. Inflammatory and autoimmune complications were found in 7 CDG types. CDG natural history(ies) and the mechanisms behind the immunological anomalies are still poorly understood. However, in some cases, alterations in pathogen recognition and intracellular signaling (eg, TGF-β1, NFAT, and NF-κB) have been suggested. Targeted therapies to restore immune defects are only available for PGM3-CDG and SLC35C1-CDG. Fostering research on glycoimmunology may elucidate the involved pathophysiological mechanisms and open new therapeutic avenues, thus improving CDG patients' quality of life.
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Affiliation(s)
- Carlota Pascoal
- Portuguese Association for CDG, Lisbon, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Rita Francisco
- Portuguese Association for CDG, Lisbon, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Tiago Ferro
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Vanessa Dos Reis Ferreira
- Portuguese Association for CDG, Lisbon, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
| | - Jaak Jaeken
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- Center for Metabolic Diseases, Department of Development and Regeneration, UZ and KU Leuven, Leuven, Belgium
| | - Paula A Videira
- Portuguese Association for CDG, Lisbon, Portugal
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
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Bosák J, Micenková L, Doležalová M, Šmajs D. Colicins U and Y inhibit growth of Escherichia coli strains via recognition of conserved OmpA extracellular loop 1. Int J Med Microbiol 2016; 306:486-494. [PMID: 27510856 DOI: 10.1016/j.ijmm.2016.07.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/28/2016] [Accepted: 07/31/2016] [Indexed: 01/04/2023] Open
Abstract
Interactions of colicins U and Y with the OmpA (Outer membrane protein A) receptor molecule were studied using site-directed mutagenesis and colicin binding assay. A systematic mutagenesis of the colicin-susceptible OmpA sequence from Escherichia coli (OmpAEC) to the colicin-resistant OmpA sequence from Serratia marcescens (OmpASM) was performed in regions corresponding to extracellular OmpA loops 1-4. Susceptibility to colicins U and Y was significantly affected by the OmpA mutation in loop 1. As with functional analysis, a decrease in binding capacity of His-tagged colicin U was found for recombinant OmpA with a mutated segment in loop 1 compared to control OmpAEC. To verify the importance of the identified amino acid residues in OmpA loop 1, we introduced loop 1 from OmpAEC into OmpASM, which resulted in the substantial increase of susceptibility to colicins U and Y. In addition, colicins U and Y were tested against a panel of 118 bacteriocin non-producing strains of four Escherichia species, including E. coli (39 strains), E. fergusonii (10 strains), E. hermannii (42 strains), and E. vulneris (27 strains). A majority (82%) of E. coli strains was susceptible to colicins U and Y. Interestingly, colicins U and Y also inhibited all of the 30 tested multidrug-resistant E. coli O25b-ST131 isolates. These findings, together with the fact that OmpA loop 1 is important for bacterial virulence and is evolutionary conserved, offer the potential of using colicins U and Y as specific anti-OmpA loop 1 directed antibacterial proteins.
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Affiliation(s)
- Juraj Bosák
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 5, Building A6, 625 00 Brno, Czech Republic
| | - Lenka Micenková
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 5, Building A6, 625 00 Brno, Czech Republic
| | - Magda Doležalová
- Department of Environment Protection Engineering, Faculty of Technology, Tomas Bata University in Zlín, T. G. Masaryk square 275, Zlín, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 5, Building A6, 625 00 Brno, Czech Republic.
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Krishnan S, Chang AC, Stoltz BM, Prasadarao NV. Escherichia coli K1 Modulates Peroxisome Proliferator-Activated Receptor γ and Glucose Transporter 1 at the Blood-Brain Barrier in Neonatal Meningitis. J Infect Dis 2016; 214:1092-104. [PMID: 27456707 DOI: 10.1093/infdis/jiw306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/13/2016] [Indexed: 12/14/2022] Open
Abstract
Escherichia coli K1 meningitis continues to be a major threat to neonatal health. Previous studies demonstrated that outer membrane protein A (OmpA) of E. coli K1 interacts with endothelial cell glycoprotein 96 (Ecgp96) in the blood-brain barrier to enter the central nervous system. Here we show that the interaction between OmpA and Ecgp96 downregulates peroxisome proliferator-activated receptor γ (PPAR-γ) and glucose transporter 1 (GLUT-1) levels in human brain microvascular endothelial cells, causing disruption of barrier integrity and inhibition of glucose uptake. The suppression of PPAR-γ and GLUT-1 by the bacteria in the brain microvessels of newborn mice causes extensive pathophysiology owing to interleukin 6 production. Pretreatment with partial or selective PPAR-γ agonists ameliorate the pathological outcomes of infection by suppressing interleukin 6 production in the brain. Thus, inhibition of PPAR-γ and GLUT-1 by E. coli K1 is a novel pathogenic mechanism in meningitis, and pharmacological upregulation of PPAR-γ and GLUT-1 levels may provide novel therapeutic avenues.
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Affiliation(s)
- Subramanian Krishnan
- Division of Infectious Diseases, Department of Pediatrics Department of Surgery, Children's Hospital Los Angeles
| | - Alexander C Chang
- Division of Infectious Diseases, Department of Pediatrics Department of Surgery, Children's Hospital Los Angeles
| | - Brian M Stoltz
- Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena
| | - Nemani V Prasadarao
- Division of Infectious Diseases, Department of Pediatrics Department of Surgery, Children's Hospital Los Angeles Keck School of Medicine, University of Southern California, Los Angeles
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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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Doran KS, Fulde M, Gratz N, Kim BJ, Nau R, Prasadarao N, Schubert-Unkmeir A, Tuomanen EI, Valentin-Weigand P. Host-pathogen interactions in bacterial meningitis. Acta Neuropathol 2016; 131:185-209. [PMID: 26744349 PMCID: PMC4713723 DOI: 10.1007/s00401-015-1531-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/26/2022]
Abstract
Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host–pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host–pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood–brain and blood–cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.
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Karassek S, Starost L, Solbach J, Greune L, Sano Y, Kanda T, Kim K, Schmidt MA. Pertussis Toxin Exploits Specific Host Cell Signaling Pathways for Promoting Invasion and Translocation of Escherichia coli K1 RS218 in Human Brain-derived Microvascular Endothelial Cells. J Biol Chem 2015; 290:24835-43. [PMID: 26324705 DOI: 10.1074/jbc.m115.650101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Indexed: 01/23/2023] Open
Abstract
Pertussis toxin (PTx), an AB5 toxin and major virulence factor of the whooping cough-causing pathogen Bordetella pertussis, has been shown to affect the blood-brain barrier. Dysfunction of the blood-brain barrier may facilitate penetration of bacterial pathogens into the brain, such as Escherichia coli K1 (RS218). In this study, we investigated the influence of PTx on blood-brain barrier permissiveness to E. coli infection using human brain-derived endothelial HBMEC and TY10 cells as in vitro models. Our results indicate that PTx acts at several key points of host cell intracellular signaling pathways, which are also affected by E. coli K1 RS218 infection. Application of PTx increased the expression of the pathogen binding receptor gp96. Further, we found an activation of STAT3 and of the small GTPase Rac1, which have been described as being essential for bacterial invasion involving host cell actin cytoskeleton rearrangements at the bacterial entry site. In addition, we showed that PTx induces a remarkable relocation of VE-cadherin and β-catenin from intercellular junctions. The observed changes in host cell signaling molecules were accompanied by differences in intracellular calcium levels, which might act as a second messenger system for PTx. In summary, PTx not only facilitates invasion of E. coli K1 RS218 by activating essential signaling cascades; it also affects intercellular barriers to increase paracellular translocation.
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Affiliation(s)
- Sascha Karassek
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Laura Starost
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Johanna Solbach
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Lilo Greune
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany
| | - Yasuteru Sano
- the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and
| | - Takashi Kanda
- the Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan, and
| | - KwangSik Kim
- the Pediatric Infectious Diseases Division, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - M Alexander Schmidt
- From the Institute of Infectiology, Center for Molecular Biology of Inflammation, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany,
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Krishnan S, Liu F, Abrol R, Hodges J, Goddard WA, Prasadarao NV. The interaction of N-glycans in Fcγ receptor I α-chain with Escherichia coli K1 outer membrane protein A for entry into macrophages: experimental and computational analysis. J Biol Chem 2014; 289:30937-49. [PMID: 25231998 DOI: 10.1074/jbc.m114.599407] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neonatal meningitis, caused by Escherichia coli K1, is a serious central nervous system disease. We have established that macrophages serve as permissive niches for E. coli K1 to multiply in the host and for attaining a threshold level of bacterial load, which is a prerequisite for the onset of the disease. Here, we demonstrate experimentally that three N-glycans in FcγRIa interact with OmpA of E. coli K1 for binding to and entering the macrophages. Adoptive transfer of FcγRIa(-/-) bone marrow-derived macrophages transfected with FcγRIa into FcγRIa(-/-) newborn mice renders them susceptible to E. coli K1-induced meningitis. In contrast, mice that received bone marrow-derived macrophages transfected with FcγRIa in which N-glycosylation sites 1, 4, and 5 are mutated to alanines exhibit resistance to E. coli K1 infection. Our molecular dynamics and simulation studies predict that N-glycan 5 exhibits strong binding at the barrel site of OmpA formed by loops 3 and 4, whereas N-glycans 1 and 4 interact with loops 1, 3, and 4 of OmpA at tip regions. Molecular modeling data also suggest no role for the IgG binding site in the invasion process. In agreement, experimental mutations in IgG binding site had no effect on the E. coli K1 entry into macrophages in vitro or on the onset of meningitis in newborn mice. Together, this integration of experimental and computational studies reveals how the N-glycans in FcγRIa interact with the OmpA of E. coli K1 for inducing the disease pathogenesis.
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Affiliation(s)
| | - Fan Liu
- the Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, and
| | - Ravinder Abrol
- the Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, and the Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Jacqueline Hodges
- From the Division of Infectious Diseases and the Department of Pediatrics and
| | - William A Goddard
- the Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, and
| | - Nemani V Prasadarao
- From the Division of Infectious Diseases and the Department of Pediatrics and the Department of Surgery, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California 90027,
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