1
|
Wang Y, Ngo VL, Zou J, Gewirtz AT. Commensal bacterial outer membrane protein A induces interleukin-22 production. Cell Rep 2024; 43:114292. [PMID: 38823020 PMCID: PMC11247541 DOI: 10.1016/j.celrep.2024.114292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/28/2024] [Accepted: 05/14/2024] [Indexed: 06/03/2024] Open
Abstract
Interleukin (IL)-22 promotes host-microbiota homeostasis. We sought to identify microbiota metabolite(s) that drive intestinal IL-22 production. We observed that exposing Peyer's patch cells (PPCs), ex vivo, to fecal supernatants (FSs) recapitulates fermentable fiber- and microbiota-dependent IL-22 production, and cellular sources thereof, thus supporting the use of this model. An interrogation of FSs generated from mice fed the fermentable fiber inulin (FS-Inu) revealed that its IL-22-inducing activity is mediated by heat-labile protein. Fractionation of FS-Inu by ion-exchange chromatography, and subsequent proteomic analysis of IL-22-inducing fractions, indicates that outer membrane protein A (OmpA) might be a microbial driver of IL-22 expression. Concomitantly, recombinant OmpA from Parabacteroides goldsteinii, which is enriched by an inulin diet, induces IL-22 production and expression of the IL-22-dependent genes REG3γ and -β, in PPCs and mice. Thus, OmpA is one bacterial inducer of IL-22 expression, potentially linking diet, mucosal immune homeostasis, and gut health.
Collapse
Affiliation(s)
- Yanling Wang
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Vu L Ngo
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Jun Zou
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Andrew T Gewirtz
- Center for Inflammation, Immunity, & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
| |
Collapse
|
2
|
Stancheva SG, Frömbling J, Sassu EL, Hennig-Pauka I, Ladinig A, Gerner W, Grunert T, Ehling-Schulz M. Proteomic and immunoproteomic insights into the exoproteome of Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia. Microb Pathog 2022; 172:105759. [PMID: 36087692 DOI: 10.1016/j.micpath.2022.105759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 10/31/2022]
Abstract
Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, a thorough analysis of the A. pleuropneumoniae exoproteome is still missing. Using a complementary approach of quantitative proteomics and immunoproteomics we gained an in-depth insight into the A. pleuropneumoniae serotype 2 exoproteome, which provides the basis for future functional studies. Label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed 593 exoproteins, of which 104 were predicted to be virulence factors. The RTX toxins ApxIIA and ApxIIIA -were found to be the most abundant proteins in the A. pleuropneumoniae serotype 2 exoproteome. Furthermore, the ApxIVA toxin was one of the proteins showing the highest abundance, although ApxIVA is commonly assumed to be expressed exclusively in vivo. Our study revealed several antigens, including proteins with moonlight functions, such as the elongation factor (EF)-Tu, and proteins linked to specific metabolic traits, such as the maltodextrin-binding protein MalE, that warrant future functional characterization and might present potential targets for novel therapeutics and vaccines. Our Ig-classes specific serological proteome analysis (SERPA) approach allowed us to explore the development of the host humoral immune response over the course of the infection. These SERPAs pinpointed proteins that might play a key role in virulence and persistence and showed that the immune response to the different Apx toxins is distinct. For instance, our results indicate that the ApxIIIA toxin has properties of a thymus-independent antigen, which should be studied in more detail.
Collapse
Affiliation(s)
- Stelli G Stancheva
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Janna Frömbling
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Elena L Sassu
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria
| | - Isabel Hennig-Pauka
- Field Station for Epidemiology, University of Veterinary Medicine Hannover, Bakum, Germany
| | - Andrea Ladinig
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Austria
| | - Wilhelm Gerner
- Institute of Immunology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tom Grunert
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department for Pathobiology, University of Veterinary Medicine Vienna, Austria.
| |
Collapse
|
3
|
Maerani M, Dewanti-Hariyadi R, Nurjanah S. Expression of stress regulator and virulence genes of Cronobacter sakazakii strain Yrt2a as a response to acid stress. Food Sci Biotechnol 2020; 29:1273-1279. [PMID: 32802566 DOI: 10.1007/s10068-020-00763-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 03/07/2020] [Accepted: 04/14/2020] [Indexed: 10/24/2022] Open
Abstract
This research aimed to evaluate the effect of acid stress on the expression of stress regulator (grxB and rpoS) and virulence (ompA, hfq, and cpa) genes of Cronobacter sakazakii Yrt2a. The results showed that C. sakazakii Yrt2a experienced decrease in number during acid stress and was no longer culturable 90 min post exposure to pH 3.0. During acid stress, the expression of grxB, rpoS, ompA, cpa and hfq was upregulated by 2.15; 2.19; 1.55; 1.1 and 1.41 log, respectively. However, all genes expression was downregulated when the bacteria entered the unculturable state. The expression of gene grxB, rpoS, ompA, cpa decreased to 1.04; 0.37; 0.84 and 1.71 log, respectively; while hfq gene expression reached a level lower than that of control. This research implies a supposition that during acid stress, C. sakazakii was capable of maintaining its culturability and pathogenicity until they are no longer culturable.
Collapse
Affiliation(s)
- Maerani Maerani
- Department of Food Science and Technology, Bogor Agricultural University, Bogor, Kampus IPB Dramaga, PO Box 220 16002, West Java 16680 Indonesia
| | - Ratih Dewanti-Hariyadi
- Department of Food Science and Technology, Bogor Agricultural University, Bogor, Kampus IPB Dramaga, PO Box 220 16002, West Java 16680 Indonesia.,Southeast Asian Food and Agricultural Science and Technology (SEAFAST) Center, Bogor Agricultural University, Bogor, West Java 16680 Indonesia
| | - Siti Nurjanah
- Department of Food Science and Technology, Bogor Agricultural University, Bogor, Kampus IPB Dramaga, PO Box 220 16002, West Java 16680 Indonesia.,Southeast Asian Food and Agricultural Science and Technology (SEAFAST) Center, Bogor Agricultural University, Bogor, West Java 16680 Indonesia
| |
Collapse
|
4
|
Nielsen DW, Ricker N, Barbieri NL, Allen HK, Nolan LK, Logue CM. Outer membrane protein A (OmpA) of extraintestinal pathogenic Escherichia coli. BMC Res Notes 2020; 13:51. [PMID: 32005127 PMCID: PMC6995065 DOI: 10.1186/s13104-020-4917-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 01/22/2020] [Indexed: 02/05/2023] Open
Abstract
Objective Extraintestinal Pathogenic E. coli (ExPEC), are responsible for host diseases such as Neonatal Meningitis Escherichia coli (NMEC), the second-leading cause of neonatal bacterial meningitis, Avian Pathogenic E. coli (APEC), a cause of extraintestinal disease in poultry, and Uropathogenic E. coli (UPEC), the most common cause of urinary tract infections. Virulence factors associated with NMEC include outer membrane protein A (OmpA) and type I fimbriae (FimH), which also occur in APEC and UPEC. OmpA contributes to NMEC’s ability to cross the blood–brain barrier, persist in the bloodstream and has been identified as a potential vaccine target for ExPEC, however the protein has amino acid variants, which may influence virulence of strains or alter vaccine efficacy. Although OmpA is present in virtually all E. coli, differences in its amino acid residues have yet to be surveyed in ExPEC. Results Here the ompA gene (n = 399) from ExPEC collections were sequenced and translated in silico. Twenty-five different OmpA polymorphism patterns were identified. Seven polymorphism patterns were significantly associated with an ExPEC subpathotype, but chromosomal history most likely accounts for most differences found. The differences in OmpA protein sequences suggest that OmpA may influence variation in virulence and host specificity within ExPEC subpathotypes.
Collapse
Affiliation(s)
- Daniel W Nielsen
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, 1802 University Blvd, Ames, IA, 50011, USA.,Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, USA
| | - Nicole Ricker
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, USA.,Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Nicolle L Barbieri
- Department of Population Health, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Heather K Allen
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, USA
| | - Lisa K Nolan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Catherine M Logue
- Department of Population Health, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA, 30602, USA.
| |
Collapse
|
5
|
Pushing beyond the Envelope: the Potential Roles of OprF in Pseudomonas aeruginosa Biofilm Formation and Pathogenicity. J Bacteriol 2019; 201:JB.00050-19. [PMID: 31010902 DOI: 10.1128/jb.00050-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The ability of Pseudomonas aeruginosa to form biofilms, which are communities of cells encased in a self-produced extracellular matrix, protects the cells from antibiotics and the host immune response. While some biofilm matrix components, such as exopolysaccharides and extracellular DNA, are relatively well characterized, the extracellular matrix proteins remain understudied. Multiple proteomic analyses of the P. aeruginosa soluble biofilm matrix and outer membrane vesicles, which are a component of the matrix, have identified OprF as an abundant matrix protein. To date, the few reports on the effects of oprF mutations on biofilm formation are conflicting, and little is known about the potential role of OprF in the biofilm matrix. The majority of OprF studies focus on the protein as a cell-associated porin. As a component of the outer membrane, OprF assumes dual conformations and is involved in solute transport, as well as cell envelope integrity. Here, we review the current literature on OprF in P. aeruginosa, discussing how the structure and function of the cell-associated and matrix-associated protein may affect biofilm formation and pathogenesis in order to inform future research on this understudied matrix protein.
Collapse
|
6
|
Liao C, Liang X, Yang F, Soupir ML, Howe AC, Thompson ML, Jarboe LR. Allelic Variation in Outer Membrane Protein A and Its Influence on Attachment of Escherichia coli to Corn Stover. Front Microbiol 2017; 8:708. [PMID: 28515712 PMCID: PMC5413513 DOI: 10.3389/fmicb.2017.00708] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 04/05/2017] [Indexed: 01/16/2023] Open
Abstract
Understanding the genetic factors that govern microbe-sediment interactions in aquatic environments is important for water quality management and reduction of waterborne disease outbreaks. Although chemical properties of bacteria have been identified that contribute to initiation of attachment, the outer membrane proteins that contribute to these chemical properties still remain unclear. In this study we explored the attachment of 78 Escherichia coli environmental isolates to corn stover, a representative agricultural residue. Outer membrane proteome analysis led to the observation of amino acid variations, some of which had not been previously described, in outer membrane protein A (OmpA) at 10 distinct locations, including each of the four extracellular loops, three of the eight transmembrane segments, the proline-rich linker and the dimerization domain. Some of the polymorphisms within loops 1, 2, and 3 were found to significantly co-occur. Grouping of sequences according to the outer loop polymorphisms revealed five distinct patterns that each occur in at least 5% of our isolates. The two most common patterns, I and II, are encoded by 33.3 and 20.5% of these isolates and differ at each of the four loops. Statistically significant differences in attachment to corn stover were observed among isolates expressing different versions of OmpA and when different versions of OmpA were expressed in the same genetic background. Most notable was the increased corn stover attachment associated with a loop 3 sequence of SNFDGKN relative to the standard SNVYGKN sequence. These results provide further insight into the allelic variation of OmpA and implicate OmpA in contributing to attachment to corn stover.
Collapse
Affiliation(s)
- Chunyu Liao
- Interdepartmental Microbiology Program, Iowa State UniversityAmes, IA, USA
| | - Xiao Liang
- Department of Agricultural and Biosystems Engineering, Iowa State UniversityAmes, IA, USA
| | - Fan Yang
- Department of Agricultural and Biosystems Engineering, Iowa State UniversityAmes, IA, USA
| | - Michelle L Soupir
- Interdepartmental Microbiology Program, Iowa State UniversityAmes, IA, USA.,Department of Agricultural and Biosystems Engineering, Iowa State UniversityAmes, IA, USA
| | - Adina C Howe
- Interdepartmental Microbiology Program, Iowa State UniversityAmes, IA, USA.,Department of Agricultural and Biosystems Engineering, Iowa State UniversityAmes, IA, USA
| | | | - Laura R Jarboe
- Interdepartmental Microbiology Program, Iowa State UniversityAmes, IA, USA.,Department of Chemical and Biological Engineering, Iowa State UniversityAmes, IA, USA
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Vega-Manriquez X, Huerta-Ascencio L, Martínez-Gómez D, López-Vidal Y, Verdugo-Rodríguez A. Influence of heat-labile serum components in the presence of OmpA on the outer membrane of Salmonella gallinarum. Arch Microbiol 2015; 198:161-9. [PMID: 26597854 DOI: 10.1007/s00203-015-1174-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 11/06/2015] [Accepted: 11/12/2015] [Indexed: 11/24/2022]
Abstract
Salmonella gallinarum is the causative agent of fowl typhoid. Being a Gram-negative bacteria, its outer membrane proteins (OMP) can be regulated by different microenvironments. S. gallinarum was cultured under the following conditions: nutrient broth (NB), NB supplemented with serum from specific pathogen-free birds (NBS) and NB with serum incubated at 56 °C prior to incubation with the bacteria (NBSD); OMP were subsequently extracted. Several changes were observed in the apparent expression of OMP, mainly a decrease in an OMP with a size of 30 kDa, approximately, under the NBS condition. In contrast, the same event was not observed in NB and NBSD when using one- and two-dimensional polyacrylamide gels (SDS-PAGE). Using the OMP with a size of 30 kDa, approximately, as antigen in indirect ELISA, we were able to differentiate serum from healthy and vaccinated birds, as well as birds infected with S. gallinarum and S. enteritidis. The amino-terminal of this protein was sequenced, showing 100 % identity with OmpA of S. typhimurium. Subsequently, we designed primers to amplify the gene by PCR. The partial sequence of the amplified gene showed 100 % identity with OmpA of S. gallinarum. (1) Heat-labile serum components influence the presence of OmpA in the OM of S. gallinarum; (2) by the way of ELISA, OmpA allows to specifically differentiate healthy from diseased birds.
Collapse
Affiliation(s)
- X Vega-Manriquez
- Facultad de Agronomía y Veterinaria, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, Mexico
| | - L Huerta-Ascencio
- Laboratorio de Microbiología Molecular, Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootencnia, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, UNAM CU, Coyoacan México, 04510, México City, Mexico
| | - D Martínez-Gómez
- Departamento de Producción Agrícola, Universidad Autónoma Metropolitana-Unidad Xochimilco, México City, Mexico
| | - Y López-Vidal
- Programa de Inmunología Molecular Microbiana, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, Mexico
| | - A Verdugo-Rodríguez
- Laboratorio de Microbiología Molecular, Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootencnia, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, UNAM CU, Coyoacan México, 04510, México City, Mexico.
| |
Collapse
|
9
|
Zhang W, Sun J, Ding W, Lin J, Tian R, Lu L, Liu X, Shen X, Qian PY. Extracellular matrix-associated proteins form an integral and dynamic system during Pseudomonas aeruginosa biofilm development. Front Cell Infect Microbiol 2015; 5:40. [PMID: 26029669 PMCID: PMC4429628 DOI: 10.3389/fcimb.2015.00040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/27/2015] [Indexed: 12/13/2022] Open
Abstract
Though the essential role of extracellular matrix in biofilm development has been extensively documented, the function of matrix-associated proteins is elusive. Determining the dynamics of matrix-associated proteins would be a useful way to reveal their functions in biofilm development. Therefore, we applied iTRAQ-based quantitative proteomics to evaluate matrix-associated proteins isolated from different phases of Pseudomonas aeruginosa ATCC27853 biofilms. Among the identified 389 proteins, 54 changed their abundance significantly. The increased abundance of stress resistance and nutrient metabolism-related proteins over the period of biofilm development was consistent with the hypothesis that biofilm matrix forms micro-environments in which cells are optimally organized to resist stress and use available nutrients. Secreted proteins, including novel putative effectors of the type III secretion system were identified, suggesting that the dynamics of pathogenesis-related proteins in the matrix are associated with biofilm development. Interestingly, there was a good correlation between the abundance changes of matrix-associated proteins and their expression. Further analysis revealed complex interactions among these modulated proteins, and the mutation of selected proteins attenuated biofilm development. Collectively, this work presents the first dynamic picture of matrix-associated proteins during biofilm development, and provides evidences that the matrix-associated proteins may form an integral and well regulated system that contributes to stress resistance, nutrient acquisition, pathogenesis and the stability of the biofilm.
Collapse
Affiliation(s)
- Weipeng Zhang
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Jin Sun
- Department of Biology, Hong Kong Baptist University Hong Kong, China
| | - Wei Ding
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Jinshui Lin
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Renmao Tian
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Liang Lu
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Xiaofen Liu
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| | - Xihui Shen
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A & F University Yangling, China
| | - Pei-Yuan Qian
- Division of Life Science, The Hong Kong University of Science and Technology Hong Kong, China
| |
Collapse
|
10
|
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]
|
11
|
Oscarsson J, Karched M, Thay B, Chen C, Asikainen S. Proinflammatory effect in whole blood by free soluble bacterial components released from planktonic and biofilm cells. BMC Microbiol 2008; 8:206. [PMID: 19038023 PMCID: PMC2612679 DOI: 10.1186/1471-2180-8-206] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 11/27/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aggregatibacter actinomycetemcomitans is an oral bacterium associated with aggressive forms of periodontitis. Increasing evidence points to a link between periodontitis and cardiovascular diseases, however, the underlying mechanisms are poorly understood. This study investigated the pathogenic potential of free-soluble surface material, released from live planktonic and biofilm A. actinomycetemcomitans cells. RESULTS By employing an ex vivo insert model (filter pore size 20 nm) we demonstrated that the A. actinomycetemcomitans strain D7S and its derivatives, in both planktonic and in biofilm life-form, released free-soluble surface material independent of outer membrane vesicles. This material clearly enhanced the production of several proinflammatory cytokines (IL-1 beta, TNF-alpha, IL-6, IL-8, MIP-1 beta) in human whole blood, as evidenced by using a cytokine antibody array and dissociation-enhanced-lanthanide-fluorescent-immunoassay. In agreement with this, quantitative real-time PCR indicated a concomitant increase in transcription of each of these cytokine genes. Experiments in which the LPS activity was blocked with polymyxin B showed that the stimulatory effect was only partly LPS-dependent, suggesting the involvement of additional free-soluble factors. Consistent with this, MALDI-TOF-MS and immunoblotting revealed release of GroEL-like protein in free-soluble form. Conversely, the immunomodulatory toxins, cytolethal distending toxin and leukotoxin, and peptidoglycan-associated lipoprotein, appeared to be less important, as evidenced by studying strain D7S cdt/ltx double, and pal single mutants. In addition to A. actinomycetemcomitans a non-oral species, Escherichia coli strain IHE3034, tested in the same ex vivo model also released free-soluble surface material with proinflammatory activity. CONCLUSION A. actinomycetemcomitans, grown in biofilm and planktonic form, releases free-soluble surface material independent of outer membrane vesicles, which induces proinflammatory responses in human whole blood. Our findings therefore suggest that release of surface components from live bacterial cells could constitute a mechanism for systemic stimulation and be of particular importance in chronic localized infections, such as periodontitis.
Collapse
Affiliation(s)
- Jan Oscarsson
- Oral Microbiology, Department of Odontology, Umeå University, SE-90187 Umeå, Sweden.
| | | | | | | | | |
Collapse
|
12
|
Karched M, Ihalin R, Eneslätt K, Zhong D, Oscarsson J, Wai SN, Chen C, Asikainen SE. Vesicle-independent extracellular release of a proinflammatory outer membrane lipoprotein in free-soluble form. BMC Microbiol 2008; 8:18. [PMID: 18226201 PMCID: PMC2257964 DOI: 10.1186/1471-2180-8-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 01/28/2008] [Indexed: 11/10/2022] Open
Abstract
Background Aggregatibacter actinomycetemcomitans is an oral bacterium associated with aggressively progressing periodontitis. Extracellular release of bacterial outer membrane proteins has been suggested to mainly occur via outer membrane vesicles. This study investigated the presence and conservation of peptidoglycan-associated lipoprotein (AaPAL) among A. actinomycetemcomitans strains, the immunostimulatory effect of AaPAL, and whether live cells release this structural outer membrane lipoprotein in free-soluble form independent of vesicles. Results The pal locus and its gene product were confirmed in clinical A. actinomycetemcomitans strains by PCR-restriction fragment length polymorphism and immunoblotting. Culturing under different growth conditions revealed no apparent requirement for the AaPAL expression. Inactivation of pal in a wild-type strain (D7S) and in its spontaneous laboratory variant (D7SS) resulted in pleiotropic cellular effects. In a cell culture insert model (filter pore size 0.02 μm), AaPAL was detected from filtrates when strains D7S and D7SS were incubated in serum or broth in the inserts. Electron microscopy showed that A. actinomycetemcomitans vesicles (0.05–0.2 μm) were larger than the filter pores and that there were no vesicles in the filtrates. The filtrates were immunoblot negative for a cytoplasmic marker, cyclic AMP (cAMP) receptor protein. An ex vivo model indicated cytokine production from human whole blood stimulated by AaPAL. Conclusion Free-soluble AaPAL can be extracellularly released in a process independent of vesicles.
Collapse
Affiliation(s)
- Maribasappa Karched
- Oral Microbiology, Department of Odontology, Umeå University, SE-90187 Umeå, Sweden.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
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: 282] [Impact Index Per Article: 16.6] [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.
Collapse
Affiliation(s)
- Stephen G J Smith
- Department of Clinical Microbiology, Trinity College Dublin, St James's Hospital, Dublin, Ireland.
| | | | | | | |
Collapse
|
14
|
Walzer G, Rosenberg E, Ron EZ. The Acinetobacter outer membrane protein A (OmpA) is a secreted emulsifier. Environ Microbiol 2006; 8:1026-32. [PMID: 16689723 DOI: 10.1111/j.1462-2920.2006.00994.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Acinetobacter strains use hydrophobic carbon sources and most of them are efficient oil degraders. They secrete a variety of emulsifiers which are efficient in producing and stabilizing oil-in-water emulsions. The bioemulsifier of Acinetobacter radioresistens KA53 (Alasan) is a high-mass complex of proteins and polysaccharides. The major emulsification activity of this complex is associated with a 45 kDa protein (AlnA), which is homologous to the outer membrane protein OmpA. The emulsification ability of AlnA depends on the presence of hydrophobic residues in the four loops spanning the transmembrane domains. The finding of a secreted OmpA was unexpected, in view of the fact that this protein is essential in all Gram-negative bacteria, has four trans-membrane domains and is considered to be an integral structural component of the outer membrane. However, secretion of an OmpA with emulsifying ability could be of physiological importance in the utilization of hydrophobic substrates as carbon sources. Here we examined the possibility that secretion of OmpA with emulsifying activity is a general property of the oil-degrading Acinetobacter strains. The results indicate that OmpA is secreted in five strains of Acinetobacter, including strain Acinetobacter sp. ADP1 whose genome has been sequenced. The ompA genes of ADP1 and an additional strain, Acinetobacter sp. V-26 were cloned and sequenced. Structure analysis of the sequence of the two proteins indicated the existence of the hydrophobic regions, previously shown to be responsible for the emulsification activity of AlnA. Further examination of the recombinant OmpA proteins indicated that they are, indeed, strong emulsifiers, even when produced in Escherichia coli. The finding that Acinetobacter OmpA has emulsifying activity and that it is secreted in five strains of Acinetobacter may be physiologically significant and suggests the involvement of this protein in biodegradation of hydrophobic substrates, including hydrocarbons.
Collapse
Affiliation(s)
- Gil Walzer
- Department of Molecular Microbiology and Biotechnology, Life Sciences, Tel-Aviv University, Tel-Aviv, Israel 69978
| | | | | |
Collapse
|
15
|
Albrecht R, Zeth K, Söding J, Lupas A, Linke D. Expression, crystallization and preliminary X-ray crystallographic studies of the outer membrane protein OmpW from Escherichia coli. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:415-8. [PMID: 16582500 PMCID: PMC2222561 DOI: 10.1107/s1744309106010190] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 03/20/2006] [Indexed: 11/10/2022]
Abstract
OmpW is an eight-stranded 21 kDa molecular-weight beta-barrel protein from the outer membrane of Gram-negative bacteria. It is a major antigen in bacterial infections and has implications in antibiotic resistance and in the oxidative degradation of organic compounds. OmpW from Escherichia coli was cloned and the protein was expressed in inclusion bodies. A method for refolding and purification was developed which yields properly folded protein according to circular-dichroism measurements. The protein has been crystallized and crystals were obtained that diffracted to a resolution limit of 3.5 angstroms. The crystals belong to space group P422, with unit-cell parameters a = 122.5, c = 105.7 angstroms. A homology model of OmpW is presented based on known structures of eight-stranded beta-barrels, intended for use in molecular-replacement trials.
Collapse
Affiliation(s)
- Reinhard Albrecht
- Max Planck Institute of Biochemistry, Department of Membrane Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Kornelius Zeth
- Max Planck Institute of Biochemistry, Department of Membrane Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
- Correspondence e-mail:
| | - Johannes Söding
- Max Planck Institute of Developmental Biology, Department of Protein Evolution, Spemannstrasse 35, D-72076 Tübingen, Germany
| | - Andrei Lupas
- Max Planck Institute of Developmental Biology, Department of Protein Evolution, Spemannstrasse 35, D-72076 Tübingen, Germany
| | - Dirk Linke
- Max Planck Institute of Developmental Biology, Department of Protein Evolution, Spemannstrasse 35, D-72076 Tübingen, Germany
| |
Collapse
|
16
|
Abstract
Extraintestinal pathogenic Escherichia coli strains (ExPEC) are the cause of a diverse spectrum of invasive human and animal infections, often leading to septicemia. This review deals with the virulence genes of septicemic ExPEC strains. We discuss the meaning of a virulence gene and survey the genomic, genetic and physiological studies on these strains. Apparently, there are a few virulence factors, which are conserved in the septicemic strains, implying that they are essential for the infection. For the other virulence-related genes a high level of diversity is observed, demonstrating that all stages of the infection can be mediated by a number of alternative virulence factors. The variable profile of virulence genes in septicemic E. coli strains, as well as a prevalence of mobility-related sequences point out the existence of a "mix and match" combinatorial system.
Collapse
Affiliation(s)
- Daphna Mokady
- Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel
| | | | | |
Collapse
|