1
|
The Metabolic Adaptation in Response to Nitrate Is Critical for Actinobacillus pleuropneumoniae Growth and Pathogenicity under the Regulation of NarQ/P. Infect Immun 2022; 90:e0023922. [PMID: 35938858 PMCID: PMC9476948 DOI: 10.1128/iai.00239-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitrate metabolism is an adaptation mechanism used by many bacteria for survival in anaerobic environments. As a by-product of inflammation, nitrate is used by the intestinal bacterial pathogens to enable gut infection. However, the responses of bacterial respiratory pathogens to nitrate are less well understood. Actinobacillus pleuropneumoniae is an important bacterial respiratory pathogen of swine. Previous studies have suggested that adaptation of A. pleuropneumoniae to anaerobiosis is important for infection. In this work, A. pleuropneumoniae growth and pathogenesis in response to the nitrate were investigated. Nitrate significantly promoted A. pleuropneumoniae growth under anaerobic conditions in vitro and lethality in mice. By using narQ and narP deletion mutants and single-residue-mutated complementary strains of ΔnarQ, the two-component system NarQ/P was confirmed to be critical for nitrate-induced growth, with Arg50 in NarQ as an essential functional residue. Transcriptome analysis showed that nitrate upregulated multiple energy-generating pathways, including nitrate metabolism, mannose and pentose metabolism, and glycerolipid metabolism via the regulation of NarQ/P. Furthermore, narQ, narP, and its target gene encoding the nitrate reductase Nap contributed to the pathogenicity of A. pleuropneumoniae. The Nap inhibitor tungstate significantly reduced the survival of A. pleuropneumoniae in vivo, suggesting that Nap is a potential drug target. These results give new insights into how the respiratory pathogen A. pleuropneumoniae utilizes the alternative electron acceptor nitrate to overcome the hypoxia microenvironment, which can occur in the inflammatory or necrotic infected tissues.
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
|
Kähl S, Volke D, Fornefett J, Fingas F, Klose K, Benga L, Grunwald T, Ulrich R, Hoffmann R, Baums CG. Identification of a large repetitive RTX immunogen in a highly virulent Rodentibacter heylii strain. Microbes Infect 2021; 23:104771. [PMID: 33164813 DOI: 10.1016/j.micinf.2020.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/15/2020] [Accepted: 10/17/2020] [Indexed: 11/30/2022]
Abstract
Rodentibacter (R.) heylii is frequently detected in laboratory rodents. Repeats in toxin (RTX) toxins are considered important virulence factors of this major murine pathogen. We evaluated the virulence of a R.heylii strain negative for all known RTX toxin genes and Muribacter (M.) muris, a commensal in mice, in experimental infections of C57BL/6 and BALB/c mice. Experimental intranasal infection with 108 CFU of the pnxI-, pnxII- and pnxIII- R. heylii strain resulted in 75% and 100% mortality in C57BL/6 and BALB/c mice, respectively. In early losses, multiple internal organs were infected and purulent bronchopneumonia was the main pathology. Intranasal application of M. muris did not result in mortality or severe weight loss. Immunoproteomics led to the identification of a surface-associated and specific immunogen, which was designated as R. heylii immunogen A (RhiA) and which was exclusively recognised by sera obtained from mice infected with this R. heylii pathotype. RhiA is a 262.6 kDa large protein containing long imperfect tandem repeats and C-terminal RTX consensus sequences. Immunohistochemical analysis confirmed that this R.heylii pathotype expresses RhiA in the lower respiratory tract. In summary, this study describes a specific immunogen in a virulent R. heylii, strain which is an excellent antigen for pathotype-specific serological screenings and which might carry out RTX-related functions.
Collapse
Affiliation(s)
- Sophie Kähl
- Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany
| | - Daniela Volke
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Centre for Biotechnology and Biomedicine, University Leipzig, 04103, Leipzig, Germany
| | - Juliane Fornefett
- Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany
| | | | - Kristin Klose
- Institute of Veterinary Pathology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany
| | - Laurentiu Benga
- Central Unit for Animal Research and Animal Welfare Affairs, Heinrich-Heine-University, University Hospital, Düsseldorf, Germany
| | - Thomas Grunwald
- Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - Reiner Ulrich
- Institute of Veterinary Pathology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany
| | - Ralf Hoffmann
- Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Centre for Biotechnology and Biomedicine, University Leipzig, 04103, Leipzig, Germany
| | - Christoph Georg Baums
- Institute of Bacteriology and Mycology, Faculty of Veterinary Medicine, University Leipzig, Leipzig, Germany.
| |
Collapse
|
4
|
Nahar N, Turni C, Tram G, Blackall PJ, Atack JM. Actinobacillus pleuropneumoniae: The molecular determinants of virulence and pathogenesis. Adv Microb Physiol 2021; 78:179-216. [PMID: 34147185 DOI: 10.1016/bs.ampbs.2020.12.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is responsible for high economic losses in swine herds across the globe. Pleuropneumonia is characterized by severe respiratory distress and high mortality. The knowledge about the interaction between bacterium and host within the porcine respiratory tract has improved significantly in recent years. A. pleuropneumoniae expresses multiple virulence factors, which are required for colonization, immune clearance, and tissue damage. Although vaccines are used to protect swine herds against A. pleuropneumoniae infection, they do not offer complete coverage, and often only protect against the serovar, or serovars, used to prepare the vaccine. This review will summarize the role of individual A. pleuropneumoniae virulence factors that are required during key stages of pathogenesis and disease progression, and highlight progress made toward developing effective and broadly protective vaccines against an organism of great importance to global agriculture and food production.
Collapse
Affiliation(s)
- Nusrat Nahar
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Conny Turni
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD, Australia
| | - Greg Tram
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Patrick J Blackall
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD, Australia.
| | - John M Atack
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
| |
Collapse
|
5
|
Hansen MJ, Kudirkiene E, Dalsgaard I. Analysis of 44 Vibrio anguillarum genomes reveals high genetic diversity. PeerJ 2020; 8:e10451. [PMID: 33344086 PMCID: PMC7719292 DOI: 10.7717/peerj.10451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 11/09/2020] [Indexed: 12/26/2022] Open
Abstract
Vibriosis, a hemorrhagic septicemic disease caused by the bacterium Vibrio anguillarum, is an important bacterial infection in Danish sea-reared rainbow trout. Despite of vaccination, outbreaks still occur, likely because the vaccine is based on V. anguillarum strains from abroad/other hosts than rainbow trout. Information about the genetic diversity of V. anguillarum specifically in Danish rainbow trout, is required to investigate this claim. Consequently, the aim of the present investigation was to sequence and to characterize a collection of 44 V. anguillarum strains obtained primarily from vibriosis outbreaks in Danish rainbow trout. The strains were sequenced, de novo assembled, and the genomes examined for the presence of plasmids, virulence, and acquired antibiotic resistance genes. To investigate the phylogeny, single nucleotide polymorphisms were identified, and the pan-genome was calculated. All strains carried tet(34) encoding tetracycline resistance, and 36 strains also contained qnrVC6 for increased fluoroquinolone/quinolone resistance. But interestingly, all strains were phenotypic sensitive to both oxytetracycline and oxolinic acid. Almost all serotype O1 strains contained a pJM1-like plasmid and nine serotype O2A strains carried the plasmid p15. The distribution of virulence genes was rather similar across the strains, although evident variance among serotypes was observed. Most significant, almost all serotype O2 and O3 strains, as well as the serotype O1 strain without a pJM1-like plasmid, carried genes encoding piscibactin biosynthesis. Hence supporting the hypothesis, that piscibactin plays a crucial role in virulence for pathogenic strains lacking the anguibactin system. The phylogenetic analysis and pan-genome calculations revealed great diversity within V. anguillarum. Serotype O1 strains were in general very similar, whereas considerable variation was found among serotype O2A strains. The great diversity within the V. anguillarum serotype O2A genomes is most likely the reason why vaccines provide good protection from some strains, but not from others. Hopefully, the new genomic data and knowledge provided in this study might help develop an optimized vaccine against V. anguillarum in the future to reduce the use of antibiotics, minimize economic losses and improve the welfare of the fish.
Collapse
Affiliation(s)
- Mie Johanne Hansen
- National Institute of Aquatic Resources Technical University of Denmark, Kongens Lyngby, Denmark
| | - Egle Kudirkiene
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Inger Dalsgaard
- National Institute of Aquatic Resources Technical University of Denmark, Kongens Lyngby, Denmark
| |
Collapse
|
6
|
Xiao J, Liu J, Bao C, Zhu R, Gu J, Sun C, Feng X, Du C, Han W, Li Y, Lei L. Recombinant tandem epitope vaccination provides cross protection against Actinobacillus pleuropneumoniae challenge in mice. AMB Express 2020; 10:123. [PMID: 32642871 PMCID: PMC7341470 DOI: 10.1186/s13568-020-01051-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/15/2020] [Indexed: 11/10/2022] Open
Abstract
Actinobacillus pleuropneumoniae (A. pleuropneumoniae/APP) is the pathogen that causes porcine contagious pleuropneumonia. Actinobacillus pleuropneumoniae is divided into 18 serovars, and the cross protection efficacy of epitopes is debatable, which has resulted in the slow development of a vaccine. Consequently, epitope-based vaccines conferring Actinobacillus pleuropneumoniae cross protection have rarely been reported. In this study, B cell epitopes in the head domain of trimeric autotransporter adhesin were predicted, and 6 epitopes were selected. Then, the predicted epitopes (Ba1, Bb5, C1, PH1 and PH2) were connected by linkers to construct a recombinant tandem antigen (rta) gene. The RTA protein encoded by the recombinant rta gene was expressed, and finally the ICR mice were immunized with the RTA protein with or without inactivated Actinobacillus pleuropneumoniae (serovars 1 and 5b) and challenged with Actinobacillus pleuropneumoniae to evaluate the protective effect of the epitope-based vaccine and combined vaccine. The mice in the RTA-immunized group and RTA plus inactivated Actinobacillus pleuropneumoniae vaccine group had a significant improvement in clinical symptoms and a higher level of antibody in the serum than those in the control group. The RTA immune group had a 40% survival rate after Actinobacillus pleuropneumoniae infection, whereas the combination of RTA and inactivated Actinobacillus pleuropneumoniae produced very strong cross immune protection in mice, at least 50% (RTA IB1 + C5) and at most 100% (RTA IB5 + C1), whereas no cross immunoprotection was found in the solo Actinobacillus pleuropneumoniae immune group. Overall, the combination of the RTA protein and inactivated bacteria significantly enhanced the cross protection effects. This implies that RTA protein in combination with a suitable inactivated Actinobacillus pleuropneumoniae strain could be a candidate vaccine for porcine contagious pleuropneumonia.
Collapse
|
7
|
Abstract
The Ca2+-dependent clip-and-link activity of large repeat-in-toxin (RTX) proteins is an exceptional posttranslational process in which an internal domain called a self-processing module (SPM) mediates Ca2+-dependent processing of a highly specific aspartate-proline (Asp-Pro) peptide bond and covalent linkage of the released aspartyl to an adjacent lysine residue through an isopeptide bond. Here, we report the solution structures of the Ca2+-loaded SPM (Ca-SPM) defining the mechanism of the autocatalytic cleavage of the Asp414-Pro415 peptide bond of the Neisseria meningitidis FrpC exoprotein. Moreover, deletion of the SPM domain in the ApxIVA protein, the FrpC homolog of Actinobacillus pleuropneumoniae, resulted in attenuation of virulence of the bacterium in a pig infection model, indicating that the Ca2+-dependent clip-and-link activity plays a role in the virulence of Gram-negative pathogens. The posttranslational Ca2+-dependent “clip-and-link” activity of large repeat-in-toxin (RTX) proteins starts by Ca2+-dependent structural rearrangement of a highly conserved self-processing module (SPM). Subsequently, an internal aspartate-proline (Asp-Pro) peptide bond at the N-terminal end of SPM breaks, and the liberated C-terminal aspartyl residue can react with a free ε-amino group of an adjacent lysine residue to form a new isopeptide bond. Here, we report a solution structure of the calcium-loaded SPM (Ca-SPM) derived from the FrpC protein of Neisseria meningitidis. The Ca-SPM structure defines a unique protein architecture and provides structural insight into the autocatalytic cleavage of the Asp-Pro peptide bond through a “twisted-amide” activation. Furthermore, in-frame deletion of the SPM domain from the ApxIVA protein of Actinobacillus pleuropneumoniae attenuated the virulence of this porcine pathogen in a pig respiratory challenge model. We hypothesize that the Ca2+-dependent clip-and-link activity represents an unconventional strategy for Gram-negative pathogens to adhere to the host target cell surface.
Collapse
|
8
|
Tang B, Pors SE, Kristensen BM, Skjerning RBJ, Olsen RH, Bojesen AM. GtxA is a virulence factor that promotes a Th2-like response during Gallibacterium anatis infection in laying hens. Vet Res 2020; 51:40. [PMID: 32156313 PMCID: PMC7065373 DOI: 10.1186/s13567-020-00764-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/31/2020] [Indexed: 01/07/2023] Open
Abstract
GtxA, a leukotoxic RTX-toxin, has been proposed a main virulence factor of Gallibacterium anatis. To evaluate the impact of GtxA during infection, we experimentally infected laying hens with a G. anatis wild-type (WT) strain and its isogenic gtxA deletion mutant (ΔgtxA), respectively, and monitored the birds during a 6 day period. Birds inoculated with ΔgtxA had significantly reduced gross lesions and microscopic changes compared to the birds inoculated with the WT strain. To assess the host response further, we quantified the expression of pro-inflammatory cytokines and apoptosis genes by RT-qPCR. In the ovarian tissue, the expression levels of IL-4 and TNF-α were significantly lower in the ΔgtxA group compared to the WT group, while IL-6 and IL-10 levels appeared similar in the two groups. In the spleen tissue of ΔgtxA infected chickens, IL-4 expression was also lower compared to the WT infected chickens. The results indicated that GtxA plays a key role in an acute cytokine-mediated Th2-like response against G. anatis infection in the ovary tissue. The pro-inflammatory response in the ovary tissue of birds inoculated with ΔgtxA mutant was thus significantly lower than the wild-type response. This was, at least partly, supported by the apoptosis gene expression levels, which were significantly higher in the ΔgtxA mutant compared to the wild-type infected chickens. In conclusion, GtxA clearly plays an important role in the pathogenesis of G. anatis infections in laying hens. Further investigations into the specific factors regulating the host response is however needed to provide a more complete understanding of the bacteria-host interaction.
Collapse
Affiliation(s)
- Bo Tang
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| | - Susanne E. Pors
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| | - Bodil M. Kristensen
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| | - Ragnhild Bager J. Skjerning
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| | - Rikke H. Olsen
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| | - Anders M. Bojesen
- grid.5254.60000 0001 0674 042XDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Stigboejlen 4, 1870 Frederiksberg C, Denmark
| |
Collapse
|
9
|
Antenucci F, Magnowska Z, Nimtz M, Roesch C, Jänsch L, Bojesen AM. Immunoproteomic characterization of outer membrane vesicles from hyper-vesiculating Actinobacillus pleuropneumoniae. Vet Microbiol 2019; 235:188-194. [PMID: 31383301 DOI: 10.1016/j.vetmic.2019.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/02/2019] [Accepted: 07/02/2019] [Indexed: 11/16/2022]
Abstract
Outer membrane vesicles (OMVs) are produced and secreted virtually by every known Gram-negative bacterium. Despite their non-live nature, they share antigenic characteristics with the bacteria they originate from. This, together with their relative ease of purification, casts the OMVs as a very promising and flexible tool in both human and veterinary vaccinology. The aim of the current work was to get an insight into the antigenic pattern of OMVs from the pig pathogen Actinobacillus pleuropneumoniae in the context of vaccine development. Accordingly, we designed a protocol combining 2D Western Blotting and mass spectrometric identification to robustly characterize the antigenic protein pattern of the vesicles. Our analysis revealed that A. pleuropneumoniae OMVs carry several immunoreactive virulence factors. Some of these proteins, LpoA, OsmY and MIDG2331_02184, have never previously been documented as antigenic in A. pleuropneumoniae or other pathogenic bacteria. Additionally, we showed that despite their relative abundance, proteins such as FrpB and DegQ do not contribute to the antigenic profile of A. pleuropneumoniae OMVs.
Collapse
Affiliation(s)
- Fabio Antenucci
- Department of Veterinary and Animal Sciences, Stigbøjlen 4, 1870 Frb. C., 1-20, Building: 301, University of Copenhagen, Copenhagen, Denmark.
| | - Zofia Magnowska
- Department of Veterinary and Animal Sciences, Stigbøjlen 4, 1870 Frb. C., 1-20, Building: 301, University of Copenhagen, Copenhagen, Denmark.
| | - Manfred Nimtz
- Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124, Braunschweig, Germany.
| | - Camille Roesch
- Izon Science Ltd, Batiment Laennec, 60 Avenue Rockefeller, 69008, Lyon, France.
| | - Lothar Jänsch
- Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124, Braunschweig, Germany.
| | - Anders Miki Bojesen
- Department of Veterinary and Animal Sciences, Stigbøjlen 4, 1870 Frb. C., 1-20, Building: 301, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
10
|
dos Santos LF, Costa Polveiro R, Scatamburlo Moreira T, Pereira Vidigal PM, Chang YF, Scatamburlo Moreira MA. Polymorphism analysis of the apxIA gene of Actinobacillus pleuropneumoniae serovar 5 isolated in swine herds from Brazil. PLoS One 2018; 13:e0208789. [PMID: 30562362 PMCID: PMC6298653 DOI: 10.1371/journal.pone.0208789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 11/26/2018] [Indexed: 11/30/2022] Open
Abstract
The bacterium Actinobacillus pleuropneumoniae is the etiological agent of Contagious Porcine Pleuropneumonia, a disease responsible for economic losses in the swine industry worldwide. A. pleuropneumoniae is capable of producing proteinaceous exotoxins responsible for inducing hemorrhagic lesions, one of which is ApxI. Few studies have conducted an in-depth evaluation of polymorphisms of the nucleotides that make up the ApxI toxin gene. Here we analyze the polymorphisms of the apxIA gene region of A. pleuropneumoniae serovar 5 isolated from swine in different regions in Brazil and report the results of molecular sequencing and phylogenetic analysis. Analysis of the apxIA gene in 60 isolates revealed the presence of genetic diversity and variability. The polymorphisms in the nucleotide sequences determined the grouping of the Brazilian sequences and five more sequences from the GenBank database into 14 different haplotypes, which formed three main groups and revealed the presence of mutations in the nucleotide sequences. The estimation of selection pressures suggests the occurrence of genetic variations by positive selective pressure on A. pleuropneumoniae in large groups of animals in relatively small spaces. These conditions presumably favor the horizontal dissemination of apxIA gene mutations within bacterial populations with host reservoirs. As a result, the same serovar can demonstrate different antigenic capacities due to mutations in the apxIA gene. These alterations in sequences of the apxIA gene could occur in other areas of countries with intense swine production, which could lead to differences in the pathogenicity and immunogenicity of each serovar and have implications for the clinical status or diagnosis of A. pleuropneumoniae.
Collapse
Affiliation(s)
- Lucas Fernando dos Santos
- Laboratory of Bacterial Diseases, Sector of Preventive Veterinary Medicine and Public Health, Veterinary Department, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
- Microbiologia Veterinária Especial LTDA (Microvet), Viçosa, Minas Gerais, Brazil
| | - Richard Costa Polveiro
- Laboratory of Bacterial Diseases, Sector of Preventive Veterinary Medicine and Public Health, Veterinary Department, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Thalita Scatamburlo Moreira
- Laboratory of Bacterial Diseases, Sector of Preventive Veterinary Medicine and Public Health, Veterinary Department, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Pedro Marcus Pereira Vidigal
- Núcleo de Análise de Biomoléculas (NuBioMol), Center of Biological Sciences, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Maria Aparecida Scatamburlo Moreira
- Laboratory of Bacterial Diseases, Sector of Preventive Veterinary Medicine and Public Health, Veterinary Department, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
- * E-mail:
| |
Collapse
|
11
|
Liu J, Cao Y, Gao L, Zhang L, Gong S, Yang J, Zhao H, Yang D, Zhao J, Meng J, Gao Q, Qi C. Outer Membrane Lipoprotein Lip40 Modulates Adherence, Colonization, and Virulence of Actinobacillus pleuropneumoniae. Front Microbiol 2018; 9:1472. [PMID: 30018613 PMCID: PMC6038445 DOI: 10.3389/fmicb.2018.01472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022] Open
Abstract
Bacterial lipoproteins are a set of membrane proteins with various functions; many of which are virulence factors of pathogenic bacteria. In the present study, we investigated the role of an outer membrane lipoprotein Lip40 in the pathogenesis of Actinobacillus pleuropneumoniae. A mutant strain (Δlip40) lacking Lip40 and a complemented strain (CΔlip40) were constructed. Δlip40 exhibited reduced adherence to the St. Jude porcine lung cells. The ability of the Δlip40 mutant to colonize the mouse lung tissues was significantly impaired compared to that of the wild type and complementation strains. Furthermore, an infection assay revealed that pigs infected with Δlip40 showed fewer clinical signs and lung lesions, indicating that Lip40 contributed to the development of porcine pleuropneumonia. Collectively, our data suggest that Lip40 is involved in the virulence of A. pleuropneumoniae.
Collapse
Affiliation(s)
- Jinlin Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Yurou Cao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Lulu Gao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Li Zhang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Siying Gong
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Jihong Yang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Haobin Zhao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Dengfu Yang
- Lichuan Municipal Bureau of Animal Husbandry and Veterinary Medicine, Lichuan, China
| | - Jin Zhao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Jianzhong Meng
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| | - Qishuang Gao
- Department of Animal Biotechnology and Cell Engineering, Wuhan Institute of Animal Husbandry and Veterinary Sciences, Wuhan Academy of Agricultural Sciences, Wuhan, China
| | - Chao Qi
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, China
| |
Collapse
|
12
|
Yee S, Blackall PJ, Turni C. Genetic diversity and toxin gene distribution among serovars ofActinobacillus pleuropneumoniaefrom Australian pigs. Aust Vet J 2018; 96:17-23. [DOI: 10.1111/avj.12660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 07/25/2017] [Accepted: 07/31/2017] [Indexed: 11/29/2022]
Affiliation(s)
- S Yee
- EcoSciences Precinct, Queensland Alliance for Agriculture and Food Innovation; The University of Queensland; Boggo Road Dutton Park Queensland 4102 Australia
| | - PJ Blackall
- EcoSciences Precinct, Queensland Alliance for Agriculture and Food Innovation; The University of Queensland; Boggo Road Dutton Park Queensland 4102 Australia
| | - C Turni
- EcoSciences Precinct, Queensland Alliance for Agriculture and Food Innovation; The University of Queensland; Boggo Road Dutton Park Queensland 4102 Australia
| |
Collapse
|
13
|
Sviridova E, Rezacova P, Bondar A, Veverka V, Novak P, Schenk G, Svergun DI, Kuta Smatanova I, Bumba L. Structural basis of the interaction between the putative adhesion-involved and iron-regulated FrpD and FrpC proteins of Neisseria meningitidis. Sci Rep 2017; 7:40408. [PMID: 28084396 PMCID: PMC5233953 DOI: 10.1038/srep40408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/06/2016] [Indexed: 01/14/2023] Open
Abstract
The iron-regulated protein FrpD from Neisseria meningitidis is an outer membrane lipoprotein that interacts with very high affinity (Kd ~ 0.2 nM) with the N-terminal domain of FrpC, a Type I-secreted protein from the Repeat in ToXin (RTX) protein family. In the presence of Ca2+, FrpC undergoes Ca2+ -dependent protein trans-splicing that includes an autocatalytic cleavage of the Asp414-Pro415 peptide bond and formation of an Asp414-Lys isopeptide bond. Here, we report the high-resolution structure of FrpD and describe the structure-function relationships underlying the interaction between FrpD and FrpC1-414. We identified FrpD residues involved in FrpC1-414 binding, which enabled localization of FrpD within the low-resolution SAXS model of the FrpD-FrpC1-414 complex. Moreover, the trans-splicing activity of FrpC resulted in covalent linkage of the FrpC1-414 fragment to plasma membrane proteins of epithelial cells in vitro, suggesting that formation of the FrpD-FrpC1-414 complex may be involved in the interaction of meningococci with the host cell surface.
Collapse
Affiliation(s)
- Ekaterina Sviridova
- Faculty of Science, University of South Bohemia Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.,Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Sciences, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Pavlina Rezacova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| | - Alexey Bondar
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Sciences, Zamek 136, 37333 Nove Hrady, Czech Republic.,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| | - Vaclav Veverka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| | - Petr Novak
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic
| | - Gundolf Schenk
- EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany
| | - Dmitri I Svergun
- EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany
| | - Ivana Kuta Smatanova
- Faculty of Science, University of South Bohemia Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic.,Center for Nanobiology and Structural Biology, Institute of Microbiology, Czech Academy of Sciences, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Ladislav Bumba
- Institute of Microbiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic
| |
Collapse
|
14
|
|
15
|
Hsu CW, Li SC, Chang NY, Chen ZW, Liao JW, Chen TH, Wang JP, Lin JH, Hsuan SL. Involvement of NF-κB in regulation of Actinobacillus pleuropneumoniae exotoxin ApxI-induced proinflammatory cytokine production in porcine alveolar macrophages. Vet Microbiol 2016; 195:128-135. [PMID: 27771058 DOI: 10.1016/j.vetmic.2016.09.020] [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] [Received: 08/04/2016] [Revised: 09/24/2016] [Accepted: 09/27/2016] [Indexed: 10/20/2022]
Abstract
Actinobacillus pleuropneumoniae is a crucial respiratory pathogen that causes fibrinous, hemorrhagic, necrotizing pleuropneumonia in pigs. A. pleuropneumoniae exotoxins (ApxI to IV) are the major virulence factors contributing to A. pleuropneumoniae pathogenesis. Previously, we demonstrated that ApxI induces the expression of proinflammatory cytokines in porcine alveolar macrophages (PAMs) via the mitogen-activated protein kinases (MAPKs) p38 and cJun NH2-terminal kinase (JNK). Nonetheless, the role of nuclear factor (NF)-κB-a transcription factor widely implicated in immune and inflammatory responses-in ApxI-elicited cytokine production has yet to be defined. In the present study, we examined the involvement of NF-κB in ApxI-elicited production of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in PAMs and investigated the correlation between NF-κB and MAPK (p38 and JNK) pathways in this event. The results of Western blot analysis, confocal microscopy, and a DNA binding activity assay revealed that the classical NF-κB pathway was activated by ApxI, as evidenced by the decreased levels of IκB and subsequent NF-κB translocation and activation in ApxI-stimulated PAMs. Moreover, the blocking of ApxI-induced NF-κB activation significantly attenuated the levels of mRNA and protein secretion of IL-1β, IL-8, and TNF-α in PAMs. Notably, the attenuation of JNK activation by a specific inhibitor (SP600125) reduced ApxI-induced NF-κB activation, whereas a p38 blocker (SB203580) had no effect on the NF-κB pathway. Further examination revealed that the level of phosphorylation at serine 536 on the NF-κB p65 subunit was dependent on JNK activity. Collectively, this study, for the first time, demonstrates a pivotal role of NF-κB in ApxI-induced IL-1β, IL-8, and TNF-α production; JNK, but not p38, may positively affect the activation of the classical NF-κB pathway.
Collapse
Affiliation(s)
- Chiung-Wen Hsu
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC; Animal Technology Laboratories, Agricultural Technology Research Institute, No. 1, Ln. 51, Dahu Rd., Hsinchu City, 30093, Taiwan, ROC
| | - Siou-Cen Li
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC; Animal Technology Laboratories, Agricultural Technology Research Institute, No. 1, Ln. 51, Dahu Rd., Hsinchu City, 30093, Taiwan, ROC
| | - Nai-Yun Chang
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC
| | - Zeng-Weng Chen
- Animal Technology Laboratories, Agricultural Technology Research Institute, No. 1, Ln. 51, Dahu Rd., Hsinchu City, 30093, Taiwan, ROC
| | - Jiunn-Wang Liao
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC
| | - Ter-Hsin Chen
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC
| | - Jyh-Perng Wang
- Animal Technology Laboratories, Agricultural Technology Research Institute, No. 1, Ln. 51, Dahu Rd., Hsinchu City, 30093, Taiwan, ROC
| | - Jiunn-Horng Lin
- Animal Technology Laboratories, Agricultural Technology Research Institute, No. 1, Ln. 51, Dahu Rd., Hsinchu City, 30093, Taiwan, ROC
| | - Shih-Ling Hsuan
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, 250 Kuo Kuang Road, Taichung, 40227, Taiwan, ROC.
| |
Collapse
|
16
|
Habibi-Anbouhi M, Azadmanesh K, Behdani M, Hajizadeh-Saffar E, Vahabpour R, Shokrgozar MA. Development and Characterization of a New Antipeptide Monoclonal Antibody Directed to Human CD20 Antigen. Cancer Biother Radiopharm 2016; 30:310-6. [PMID: 26352927 DOI: 10.1089/cbr.2015.1863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The rapid expansion of immunotherapeutic approaches for treatment of various diseases, including cancers, has been greatly facilitated by the invention of new generation of antibodies. Clinical studies have indicated that anti-CD20 mAb-based therapies represent an effective treatment for various diseases with overexpression of CD20 on their cell surface, such as non-Hodgkin's lymphoma, hemolytic anemia, as well as autoimmune diseases like rheumatoid arthritis. Technically, due to a short extra membrane domain, the recombinant CD20 protein is a difficult antigen to raise immune responses. In search for new monoclonal antibodies, the authors used an antigenic polypeptide, which yielded numbers of new binders that may lead to production of anti-CD20 antibodies, with improved diagnostic or clinical attributes. Mice were immunized with extra membrane loop of human CD20 (exCD20) polypeptide. The exCD20 antigen showed a desired immune response and was able to develop a monoclonal antibody, 3B4C10, which reacted well with peptide antigen as well as native antigen on the surface of Raji B-cell line. The antibody 3B4C10 with a balanced K(on) and K(off) may be applicable in the construction of affinity columns or beads for isolation and purification of CD20-positive cells and cancer stem cells.
Collapse
Affiliation(s)
| | | | - Mahdi Behdani
- 3 Venom & Biotherapeutics Molecules Laboratory, Biotechnology Research Center, Pasteur Institute of Iran , Tehran, Iran
| | - Ensiyeh Hajizadeh-Saffar
- 4 Department of Regenerative Medicine at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology , ACECR, Tehran, Iran
| | - Rouhollah Vahabpour
- 5 Department of Hepatitis and AIDS, Pasteur Institute of Iran , Tehran, Iran
| | | |
Collapse
|
17
|
Liu J, Hu L, Xu Z, Tan C, Yuan F, Fu S, Cheng H, Chen H, Bei W. Actinobacillus pleuropneumoniae two-component system QseB/QseC regulates the transcription of PilM, an important determinant of bacterial adherence and virulence. Vet Microbiol 2015; 177:184-92. [PMID: 25796134 DOI: 10.1016/j.vetmic.2015.02.033] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/23/2015] [Accepted: 02/28/2015] [Indexed: 01/01/2023]
Abstract
QseB/QseC is one of the five predicted two-component systems (TCSs) in Actinobacillus pleuropneumoniae. To understand the roles of this TCS in A. pleuropneumoniae, a markerless gene-deletion mutant ΔqseBC was constructed. Differentially expressed (DE) genes in ΔqseBC were filtered by microarray analysis. A total of 44 DE genes were found to be regulated by QseB/QseC system. The transcriptional profile of A. pleuropneumoniae ΔqseBC was compared with that of ΔluxS and catecholamine (CA) stimulations, 13 genes regulated by QseB/QseC were found also regulated by LuxS, and 3 Qse-regulons were co-regulated by CA stimulations, respectively. Binding of QseB to the promoters of three regulons (pilM, glpK and hugZ), which were co-regulated by QseB/QseC and LuxS, was evaluated by electrophoretic mobility-shift assay. Results indicated that pilM was directly regulated by phosphorylated-QseB. Then the pilM deletion mutant ΔpilM was constructed and characterized. Data presented here revealed that adherence ability of ΔpilM to St. Jude porcine lung cells was significantly decreased, and ΔpilM exhibited reduced virulence in pigs, suggesting PilM contributes to the process of A. pleuropneumoniae infection.
Collapse
Affiliation(s)
- Jinlin Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China; College of Life Sciences, Central China Normal University, Wuhan, Hubei 430079, China
| | - Linlin Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Zhuofei Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Fangyan Yuan
- Hubei Key Laboratory of Animal Embryo and Molecular Breeding, Institute of Animal Husbandry and Veterinary Sciences, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Shulin Fu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Hui Cheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Weicheng Bei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
| |
Collapse
|
18
|
Yuan F, Liu J, Guo Y, Tan C, Fu S, Zhao J, Chen H, Bei W. Influences of ORF1 on the Virulence and Immunogenicity of Actinobacillus pleuropneumoniae. Curr Microbiol 2011; 63:574-80. [DOI: 10.1007/s00284-011-0016-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
|
19
|
Seo KW, Kim DH, Kim AH, Yoo HS, Lee KY, Jang YS. Characterization of Antigenic Determinants in ApxIIA Exotoxin Capable of Inducing Protective Immunity toActinobacillus pleuropneumoniaeChallenge. Immunol Invest 2011; 40:465-80. [DOI: 10.3109/08820139.2011.558151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
20
|
Linhartová I, Bumba L, Mašín J, Basler M, Osička R, Kamanová J, Procházková K, Adkins I, Hejnová-Holubová J, Sadílková L, Morová J, Sebo P. RTX proteins: a highly diverse family secreted by a common mechanism. FEMS Microbiol Rev 2011; 34:1076-112. [PMID: 20528947 PMCID: PMC3034196 DOI: 10.1111/j.1574-6976.2010.00231.x] [Citation(s) in RCA: 360] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Repeats-in-toxin (RTX) exoproteins of Gram-negative bacteria form a steadily growing family of proteins with diverse biological functions. Their common feature is the unique mode of export across the bacterial envelope via the type I secretion system and the characteristic, typically nonapeptide, glycine- and aspartate-rich repeats binding Ca2+ ions. In this review, we summarize the current state of knowledge on the organization of rtx loci and on the biological and biochemical activities of therein encoded proteins. Applying several types of bioinformatic screens on the steadily growing set of sequenced bacterial genomes, over 1000 RTX family members were detected, with the biological functions of most of them remaining to be characterized. Activities of the so far characterized RTX family members are then discussed and classified according to functional categories, ranging from the historically first characterized pore-forming RTX leukotoxins, through the large multifunctional enzymatic toxins, bacteriocins, nodulation proteins, surface layer proteins, up to secreted hydrolytic enzymes exhibiting metalloprotease or lipase activities of industrial interest.
Collapse
Affiliation(s)
- Irena Linhartová
- Institute of Microbiology AS CR v.v.i., Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
O’Neilla C, Jones SC, Bossé JT, Watson CM, Williamson SM, Rycroft AN, Simon Kroll J, Hartley HM, Langford PR. Population-based analysis of Actinobacillus pleuropneumoniae ApxIVA for use as a DIVA antigen. Vaccine 2010; 28:4871-4874. [PMID: 20483193 PMCID: PMC4843962 DOI: 10.1016/j.vaccine.2010.04.113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/22/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
Abstract
APXIVA is an RTX toxin of Actinobacillus pleuropneumoniae that is a candidate antigen to differentiate infected from vaccinated animals (DIVA). Insertion of ISApl1 into the apxIVA gene is known to compromise an APXIVA-based DIVA approach, as is potentially a TGG to TGA mutation in the apxIVA gene. ISApl1 was found in 63/349 (18.1%) A. pleuropneumoniae isolates from England and Wales including serovars 2, 3, 6-8 and 12. No ISApl1 insertions into apxIVA were found. Only two serovar 3 isolates contained the TGG to TGA mutation. We conclude that an ApxIVA-based DIVA approach would potentially be viable in England and Wales.
Collapse
Affiliation(s)
- Ciaragh O’Neilla
- Molecular Infectious Diseases Group, Department of Paediatrics, Imperial College London, St Mary’s Campus, London, W2 1PG, UK
| | - Sophie C.P. Jones
- Molecular Infectious Diseases Group, Department of Paediatrics, Imperial College London, St Mary’s Campus, London, W2 1PG, UK
| | - Janine T. Bossé
- Molecular Infectious Diseases Group, Department of Paediatrics, Imperial College London, St Mary’s Campus, London, W2 1PG, UK
| | | | - Susanna M. Williamson
- Veterinary Laboratories Agency (VLA) Bury St Edmunds, Rougham Hill, Bury St Edmunds, Suffolk, IP33 2RX, UK
| | - Andrew N. Rycroft
- Department of Pathology and Infectious Diseases, Royal Veterinary College, Hawkshead Lane, North Mimms, Herts AL9 7TA, UK
| | - J. Simon Kroll
- Molecular Infectious Diseases Group, Department of Paediatrics, Imperial College London, St Mary’s Campus, London, W2 1PG, UK
| | | | - Paul R. Langford
- Molecular Infectious Diseases Group, Department of Paediatrics, Imperial College London, St Mary’s Campus, London, W2 1PG, UK
| |
Collapse
|
22
|
Chiers K, De Waele T, Pasmans F, Ducatelle R, Haesebrouck F. Virulence factors of Actinobacillus pleuropneumoniae involved in colonization, persistence and induction of lesions in its porcine host. Vet Res 2010; 41:65. [PMID: 20546697 PMCID: PMC2899255 DOI: 10.1051/vetres/2010037] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2009] [Accepted: 06/10/2010] [Indexed: 12/17/2022] Open
Abstract
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The virulence factors of this microorganism involved in colonization and the induction of lung lesions have been thoroughly studied and some have been well characterized. A. pleuropneumoniae binds preferentially to cells of the lower respiratory tract in a process involving different adhesins and probably biofilm formation. Apx toxins and lipopolysaccharides exert pathogenic effects on several host cells, resulting in typical lung lesions. Lysis of host cells is essential for the bacterium to obtain nutrients from the environment and A. pleuropneumoniae has developed several uptake mechanisms for these nutrients. In addition to persistence in lung lesions, colonization of the upper respiratory tract – and of the tonsils in particular – may also be important for long-term persistent asymptomatic infection. Information on virulence factors involved in tonsillar and nasal cavity colonization and persistence is scarce, but it can be speculated that similar features as demonstrated for the lung may play a role.
Collapse
Affiliation(s)
- Koen Chiers
- Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
| | | | | | | | | |
Collapse
|
23
|
New plasmid tools for genetic analysis of Actinobacillus pleuropneumoniae and other pasteurellaceae. Appl Environ Microbiol 2009; 75:6124-31. [PMID: 19666733 DOI: 10.1128/aem.00809-09] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have generated a set of plasmids, based on the mobilizable shuttle vector pMIDG100, which can be used as tools for genetic manipulation of Actinobacillus pleuropneumoniae and other members of the Pasteurellaceae. A tandem reporter plasmid, pMC-Tandem, carrying promoterless xylE and gfpmut3 genes downstream of a multiple-cloning site (MCS), can be used for identification of transcriptional regulators and conditions which favor gene expression from different cloned promoters. The ability to detect transcriptional regulators using the tandem reporter system was validated in A. pleuropneumoniae using the cloned rpoE (sigma(E)) promoter (P). The resulting plasmid, pMCrpoEP, was used to identify a mutant defective in production of RseA, the negative regulator of sigma(E), among a bank of random transposon mutants, as well as to detect induction of sigma(E) following exposure of A. pleuropneumoniae to ethanol or heat shock. pMCsodCP, carrying the cloned sodC promoter of A. pleuropneumoniae, was functional in A. pleuropneumoniae, Haemophilus influenzae, Haemophilus parasuis, Mannheimia haemolytica, and Pasteurella multocida. Two general expression vectors, pMK-Express and pMC-Express, which differ in their antibiotic resistance markers (kanamycin and chloramphenicol, respectively), were constructed for the Pasteurellaceae. Both plasmids have the A. pleuropneumoniae sodC promoter upstream of the gfpmut3 gene and an extended MCS. Replacement of gfpmut3 with a gene of interest allows complementation and heterologous gene expression, as evidenced by expression of the Haemophilus ducreyi nadV gene in A. pleuropneumoniae, rendering the latter NAD independent.
Collapse
|