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Xiao Y, Yan F, Cui Y, Du J, Hu G, Zhai W, Liu R, Zhang Z, Fang J, Chen L, Yu X. A symbiotic bacterium of Antarctic fish reveals environmental adaptability mechanisms and biosynthetic potential towards antibacterial and cytotoxic activities. Front Microbiol 2023; 13:1085063. [PMID: 36713225 PMCID: PMC9882997 DOI: 10.3389/fmicb.2022.1085063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/14/2022] [Indexed: 01/15/2023] Open
Abstract
Antarctic microbes are important agents for evolutionary adaptation and natural resource of bioactive compounds, harboring the particular metabolic pathways to biosynthesize natural products. However, not much is known on symbiotic microbiomes of fish in the Antarctic zone. In the present study, the culture method and whole-genome sequencing were performed. Natural product analyses were carried out to determine the biosynthetic potential. We report the isolation and identification of a symbiotic bacterium Serratia myotis L7-1, that is highly adaptive and resides within Antarctic fish, Trematomus bernacchii. As revealed by genomic analyses, Antarctic strain S. myotis L7-1 possesses carbohydrate-active enzymes (CAZymes), biosynthetic gene clusters (BGCs), stress response genes, antibiotic resistant genes (ARGs), and a complete type IV secretion system which could facilitate competition and colonization in the extreme Antarctic environment. The identification of microbiome gene clusters indicates the biosynthetic potential of bioactive compounds. Based on bioactivity-guided fractionation, serranticin was purified and identified as the bioactive compound, showing significant antibacterial and antitumor activity. The serranticin gene cluster was identified and located on the chrome. Furthermore, the multidrug resistance and strong bacterial antagonism contribute competitive advantages in ecological niches. Our results highlight the existence of a symbiotic bacterium in Antarctic fish largely represented by bioactive natural products and the adaptability to survive in the fish living in Antarctic oceans.
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Affiliation(s)
- Yu Xiao
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Fangfang Yan
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Yukun Cui
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Jiangtao Du
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Guangzhao Hu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Wanying Zhai
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Rulong Liu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Zhizhen Zhang
- Ocean College, Zhoushan Campus, Zhejiang University, Zhoushan, China
| | - Jiasong Fang
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China
| | - Liangbiao Chen
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China,*Correspondence: Liangbiao Chen, ✉
| | - Xi Yu
- Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai, China,Xi Yu, ✉
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Luu LDW, Octavia S, Zhong L, Raftery M, Sintchenko V, Lan R. Characterisation of the Bordetella pertussis secretome under different media. J Proteomics 2017; 158:43-51. [PMID: 28242451 DOI: 10.1016/j.jprot.2017.02.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 01/07/2023]
Abstract
Our understanding of the Bordetella pertussis secretome remains limited including the role of different growth conditions in the secretome. In this study the secretome of L1423, a clinical isolate from the 2008-2012 Australian epidemic, cultured on Stainer-Scholte (SS) and Thalen-IJssel (THIJS) media for 12h was characterised using liquid chromatography-mass spectrometry (LC-MS/MS). In the supernatant, LC-MS/MS identified 260 proteins with 143 bioinformatically predicted to be secreted. Eighty percent of proteins were identified in both media. Proteins secreted were functionally associated with cell surface (41%), pathogenicity (16%) and transport (17%). The most abundant proteins identified were pathogenic proteins including toxins (PtxA and CyaA), adhesins (TcfA) and type III secretion (T3SS) proteins. There were 46 proteins found uniquely in THIJS including 8 virulence associated proteins. These included T3SS proteins, adhesins (FhaL and FhaS) and a putative toxin (BP1251). Nine proteins were found uniquely in SS and these were metabolic and transport-related proteins. None of the unique proteins detected in SS were known to be virulence associated. This study found that THIJS promotes secretion of virulence factors based on the number of unique virulence proteins found and may be a growth media of choice for the study of B. pertussis virulence and vaccine development. BIOLOGICAL SIGNIFICANCE Over the past two decades, the number of B. pertussis notifications has risen despite vaccination. There is a greater need to understand the biology behind B. pertussis infections. The secretome of B. pertussis in two different media was characterised using LC-MS/MS. The results showed that THIJS promotes secretion of importance virulence factors which may be important for the development of vaccines.
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Affiliation(s)
- Laurence Don Wai Luu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Sophie Octavia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ling Zhong
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Mark Raftery
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Vitali Sintchenko
- Centre for Infectious Diseases and Microbiology-Public Health, Institute of Clinical Pathology and Medical Research - Pathology West, Westmead Hospital, New South Wales, Australia; Marie Bashir Institute for Infectious Diseases and Biosecurity, Sydney Medical School, University of Sydney, New South Wales, Australia
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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3
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Park J, Zhang Y, Chen C, Dudley EG, Harvill ET. Diversity of secretion systems associated with virulence characteristics of the classical bordetellae. MICROBIOLOGY-SGM 2015; 161:2328-40. [PMID: 26459829 DOI: 10.1099/mic.0.000197] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Secretion systems are key virulence factors, modulating interactions between pathogens and the host's immune response. Six potential secretion systems (types 1-6; T1SS-T6SS) have been discussed in classical bordetellae, respiratory commensals/pathogens of mammals. The prototypical Bordetella bronchiseptica strain RB50 genome seems to contain all six systems, whilst two human-restricted subspecies, Bordetella parapertussis and Bordetella pertussis, have lost different subsets of these. This implicates secretion systems in the divergent evolutionary histories that have led to their success in different niches. Based on our previous work demonstrating that changes in secretion systems are associated with virulence characteristics, we hypothesized there would be substantial divergence of the loci encoding each amongst sequenced strains. Here, we describe extensive differences in secretion system loci; 10 of the 11 sequenced strains had lost subsets of genes or one entire secretion system locus. These loci contained genes homologous to those present in the respective loci in distantly related organisms, as well as genes unique to bordetellae, suggesting novel and/or auxiliary functions. The high degree of conservation of the T3SS locus, a complex machine with interdependent parts that must be conserved, stands in dramatic contrast to repeated loss of T5aSS 'autotransporters', which function as an autonomous unit. This comparative analysis provided insights into critical aspects of each pathogen's adaptation to its different niche, and the relative contributions of recombination, mutation and horizontal gene transfer. In addition, the relative conservation of various secretion systems is an important consideration in the ongoing search for more highly conserved protective antigens for the next generation of pertussis vaccines.
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Affiliation(s)
- Jihye Park
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA 2 Graduate Program in Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, USA
| | - Ying Zhang
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
| | - Chun Chen
- 3 Department of Food Science, Pennsylvania State University, University Park, PA, USA
| | - Edward G Dudley
- 3 Department of Food Science, Pennsylvania State University, University Park, PA, USA
| | - Eric T Harvill
- 1 Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA 4 Singapore Centre on Environmental Life Sciences Engineering, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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4
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Abstract
Pertussis toxin, produced and secreted by the whooping cough agent Bordetella pertussis, is one of the most complex soluble bacterial proteins. It is actively secreted through the B. pertussis cell envelope by the Ptl secretion system, a member of the widespread type IV secretion systems. The toxin is composed of five subunits (named S1 to S5 according to their decreasing molecular weights) arranged in an A-B structure. The A protomer is composed of the enzymatically active S1 subunit, which catalyzes ADP-ribosylation of the α subunit of trimeric G proteins, thereby disturbing the metabolic functions of the target cells, leading to a variety of biological activities. The B oligomer is composed of 1S2:1S3:2S4:1S5 and is responsible for binding of the toxin to the target cell receptors and for intracellular trafficking via receptor-mediated endocytosis and retrograde transport. The toxin is one of the most important virulence factors of B. pertussis and is a component of all current vaccines against whooping cough.
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Affiliation(s)
- Camille Locht
- Inserm U1019, CNRS UMR8204, Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Univ Lille Nord de France, France.
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Millen SH, Lewallen DM, Herr AB, Iyer SS, Weiss AA. Identification and characterization of the carbohydrate ligands recognized by pertussis toxin via a glycan microarray and surface plasmon resonance. Biochemistry 2010; 49:5954-67. [PMID: 20515023 DOI: 10.1021/bi100474z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Binding of pertussis toxin (PTx) was examined by a glycan microarray; 53 positive hits fell into four general groups. One group represents sialylated biantennary compounds with an N-glycan core terminating in alpha2-6-linked sialic acid. The second group consists of multiantennary compounds with a canonical N-glycan core, but lacking terminal sialic acids, which represents a departure from the previous understanding of PTx binding to N-glycans. The third group consists of Neu5Acalpha2-3(lactose or N-acetyllactosamine) forms that lack the branched mannose core found in N-glycans; thus, their presentation is more similar to that of O-linked glycans and glycolipids. The fourth group of compounds consists of Neu5Acalpha2-8Neu5Acalpha2-8Neu5Ac, which is seen in the c series gangliosides and some N-glycans. Quantitative analysis by surface plasmon resonance of the relative affinities of PTx for terminal Neu5Acalpha2-3 versus Neu5Acalpha2-6, as well as the affinities for the trisaccharide Neu5Acalpha2-8Neu5Acalpha2-8Neu5Ac versus disaccharide, revealed identical global affinities, even though the amount of bound glycan varied by 4-5-fold. These studies suggest that the conformational space occupied by a glycan can play an important role in binding, independent of affinity. Characterization of N-terminal and C-terminal binding sites on the S2 and S3 subunits by mutational analysis revealed that binding to all sialylated compounds was mediated by the C-terminal binding sites, and binding to nonsialylated N-linked glycans is mediated by the N-terminal sites present on both the S2 and S3 subunits. A detailed understanding of the glycans recognized by pertussis toxin is essential to understanding which cells are targeted in clinical disease.
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Affiliation(s)
- Scott H Millen
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524, USA
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6
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Synergic effect of genotype changes in pertussis toxin and pertactin on adaptation to an acellular pertussis vaccine in the murine intranasal challenge model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:807-12. [PMID: 20357056 DOI: 10.1128/cvi.00449-09] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Bordetella pertussis pertussis toxin and pertactin (Prn) are protective antigens and are contained in acellular pertussis vaccines. Polymorphisms in the A subunit of pertussis toxin (PtxA) and pertactin have been proposed to mediate vaccine resistance and contribute to pertussis reemergence. To test this hypothesis, previous studies compared clinical isolates expressing different alleles for the proteins. However, other virulence factors or virulence factor expression levels also may vary, confounding the analysis. To overcome these limitations, we constructed isogenic mutants of B. pertussis Tohama expressing the alleles ptxA1 or ptxA2 and prn1 or prn2 and compared the efficacies of an acellular pertussis vaccine against the mutants in a mouse model. While the vaccine was effective against all of the B. pertussis strains regardless of the allele expression pattern, the strain expressing ptxA1 and prn2 displayed a survival advantage over the other strains. These results suggest that an allele shift to the ptxA1 prn2 genotype may play a role in the emergence of pertussis in vaccinated populations.
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7
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Kannan TR, Musatovova O, Balasubramanian S, Cagle M, Jordan JL, Krunkosky TM, Davis A, Hardy RD, Baseman JB. Mycoplasma pneumoniae Community Acquired Respiratory Distress Syndrome toxin expression reveals growth phase and infection-dependent regulation. Mol Microbiol 2010; 76:1127-41. [PMID: 20199607 PMCID: PMC2883071 DOI: 10.1111/j.1365-2958.2010.07092.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mycoplasma pneumoniae causes acute and chronic respiratory infections, including tracheobronchitis and community acquired pneumonia, and is linked to asthma and an array of extra-pulmonary disorders. Recently, we identified an ADP-ribosylating and vacuolating toxin of M. pneumoniae, designated Community Acquired Respiratory Distress Syndrome (CARDS) toxin. In this study we analysed CARDS toxin gene (annotated mpn372) transcription and identified its promoter. We also compared CARDS toxin mRNA and protein profiles in M. pneumoniae during distinct in vitro growth phases. CARDS toxin mRNA expression was maximal, but at low levels, during early exponential growth and declined sharply during mid-to-late log growth phases, which was in direct contrast to other mycoplasma genes examined. Between 7% and 10% of CARDS toxin was localized to the mycoplasma membrane at mid-exponential growth, which was reinforced by immunogold electron microscopy. No CARDS toxin was released into the medium. Upon M. pneumoniae infection of mammalian cells, increased expression of CARDS toxin mRNA was observed when compared with SP-4 broth-grown cultures. Further, confocal immunofluorescence microscopy revealed that M. pneumoniae readily expressed CARDS toxin during infection of differentiated normal human bronchial epithelial cells. Analysis of M. pneumoniae-infected mouse lung tissue revealed high expression of CARDS toxin per mycoplasma cell when compared with M. pneumoniae cells grown in SP-4 medium alone. Taken together, these studies indicate that CARDS toxin expression is carefully controlled by environmental cues that influence its transcription and translation. Further, the acceleration of CARDS toxin synthesis and accumulation in vivo is consistent with its role as a bona fide virulence determinant.
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Affiliation(s)
- T R Kannan
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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8
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Characterization of a unique ADP-ribosyltransferase of Mycoplasma penetrans. Infect Immun 2009; 77:4362-70. [PMID: 19651868 DOI: 10.1128/iai.00044-09] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycoplasma penetrans is a urogenital tract pathogen implicated in the deterioration of the immune system in human immunodeficiency virus-infected AIDS patients. Here, we describe a 78-kDa protein from M. penetrans, designated MYPE9110, that exhibits sequence similarity to known ADP-ribosyltransferases (ADPRTs) such as Bordetella pertussis pertussis toxin and Mycoplasma pneumoniae community-acquired respiratory distress syndrome toxin. MYPE9110 possesses key amino acid residues found in all ADPRTs that are essential for ADPRT activity. Several mammalian cell proteins are ADP-ribosylated by MYPE9110, and the full-length recombinant protein exhibits a strong auto-ADP-ribosylating activity. In the absence of target proteins, MYPE9110 demonstrates a NAD-glycohydrolase activity by hydrolyzing NAD. Furthermore, this toxin elicits cytopathology in HeLa cells by inducing cytoplasmic vacuolization in the presence of ammonium chloride. The deletion of the C-terminal region of MYPE9110 significantly diminishes its binding to host cells while still exhibiting an ADPRT activity, suggesting that MYPE9110 is a member of the family of A-B ADPRT toxins.
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9
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Schneider OD, Weiss AA, Miller WE. Pertussis toxin signals through the TCR to initiate cross-desensitization of the chemokine receptor CXCR4. THE JOURNAL OF IMMUNOLOGY 2009; 182:5730-9. [PMID: 19380820 DOI: 10.4049/jimmunol.0803114] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pertussis toxin (PTx) has been shown to exert a variety of effects on immune cells independent of its ability to ADP-ribosylate G proteins. Of these effects, the binding subunit of PTx (PTxB) has been shown to block signaling via the chemokine receptor CCR5, but the mechanism involved in this process is unknown. Here, we show that PTxB causes desensitization of a related chemokine receptor, CXCR4, and explore the mechanism by which this occurs. CXCR4 is the receptor for the chemokine stromal cell-derived factor 1alpha (SDF-1alpha) and elicits a number of biological effects, including stimulation of T cell migration. PTxB treatment causes a decrease in CXCR4 surface expression, inhibits G protein-associated signaling, and blocks SDF-1alpha-mediated chemotaxis. We show that PTxB mediates these effects by activating the TCR signaling network, as the effects are dependent on TCR and ZAP70 expression. Additionally, the activation of the TCR with anti-CD3 mAb elicits a similar set of effects on CXCR4 activity, supporting the idea that TCR signaling leads to cross-desensitization of CXCR4. The inhibition of CXCR4 by PTxB is rapid and transient; however, the catalytic activity of PTx prevents CXCR4 signaling in the long term. Thus, the effects of PTx holotoxin on CXCR4 signaling can be divided into two phases: short term by the B subunit, and long term by the catalytic subunit. These data suggest that TCR crosstalk with CXCR4 is likely a normal cellular process that leads to cross-desensitization, which is exploited by the B subunit of PTx.
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Affiliation(s)
- Olivia D Schneider
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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10
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Shrivastava R, Miller JF. Virulence factor secretion and translocation by Bordetella species. Curr Opin Microbiol 2009; 12:88-93. [PMID: 19186097 DOI: 10.1016/j.mib.2009.01.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Revised: 12/29/2008] [Accepted: 01/02/2009] [Indexed: 01/24/2023]
Abstract
Here we review the Bordetella virulence secretome with an emphasis on factors that translocate into target cells. Recent advances in understanding the functions of adenylate cyclase toxin, a type 1 secretion system (T1SS) substrate, and pertussis toxin, a type IV secretion system (T4SS) substrate, are briefly described and a compilation of additional secretion systems and secreted factors is provided. Particular attention is devoted to the Bsc type III secretion system (T3SS) and controversies surrounding it. Efforts to identify effector proteins, characterize in vitro and in vivo phenotypes, and the potential role of type III secretion during human infections are discussed.
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Affiliation(s)
- Ruchi Shrivastava
- Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
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11
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Immunoproteomic analysis of Bordetella pertussis and identification of new immunogenic proteins. Vaccine 2009; 27:542-8. [DOI: 10.1016/j.vaccine.2008.11.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 10/30/2008] [Accepted: 11/03/2008] [Indexed: 11/21/2022]
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12
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Juhas M, Crook DW, Hood DW. Type IV secretion systems: tools of bacterial horizontal gene transfer and virulence. Cell Microbiol 2008; 10:2377-86. [PMID: 18549454 PMCID: PMC2688673 DOI: 10.1111/j.1462-5822.2008.01187.x] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Type IV secretion systems (T4SSs) are multisubunit cell-envelope-spanning structures, ancestrally related to bacterial conjugation machines, which transfer proteins and nucleoprotein complexes across membranes. T4SSs mediate horizontal gene transfer, thus contributing to genome plasticity and the evolution of pathogens through dissemination of antibiotic resistance and virulence genes. Moreover, T4SSs are also used for the delivery of bacterial effector proteins across the bacterial membrane and the plasmatic membrane of eukaryotic host cell, thus contributing directly to pathogenicity. T4SSs are usually encoded by multiple genes organized into a single functional unit. Based on a number of features, the organization of genetic determinants, shared homologies and evolutionary relationships, T4SSs have been divided into several groups. Type F and P (type IVA) T4SSs resembling the archetypal VirB/VirD4 system of Agrobacterium tumefaciens are considered to be the paradigm of type IV secretion, while type I (type IVB) T4SSs are found in intracellular bacterial pathogens, Legionella pneumophila and Coxiella burnetii. Several novel T4SSs have been identified recently and their functions await investigation. The most recently described GI type T4SSs play a key role in the horizontal transfer of a wide variety of genomic islands derived from a broad spectrum of bacterial strains.
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Affiliation(s)
- Mario Juhas
- Clinical Microbiology and Infectious Diseases, Nuffield Department of Clinical Laboratory Sciences, University of Oxford, Oxford OX3 9DU, UK.
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13
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Schneider OD, Weiss AA, Miller WE. Pertussis toxin utilizes proximal components of the T-cell receptor complex to initiate signal transduction events in T cells. Infect Immun 2007; 75:4040-9. [PMID: 17562776 PMCID: PMC1951969 DOI: 10.1128/iai.00414-07] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pertussis toxin (PTx) is an AB(5) toxin produced by the human pathogen Bordetella pertussis. Previous work demonstrates that the five binding (B) subunits of PTx can have profound effects on T lymphocytes independent of the enzymatic activity of the A subunit. Stimulation of T cells with holotoxin (PTx) or the B subunit alone (PTxB) rapidly induces signaling events resulting in inositol phosphate accumulation, Ca(2+) mobilization, interleukin-2 (IL-2) production, and mitogenic cell growth. Although previous reports suggest the presence of PTx signaling receptors expressed on T cells, to date, the receptor(s) and membrane proximal signaling events utilized by PTx remain unknown. Here we genetically and biochemically define the membrane proximal components utilized by PTx to initiate signal transduction in T cells. Using mutants of the Jurkat T-cell line deficient for key components of the T-cell receptor (TCR) pathway, we have compared stimulation with PTx to that of anti-CD3 monoclonal antibody (MAb), which directly interacts with and activates the TCR complex. Our genetic data in combination with biochemical analysis show that PTx (via the B subunit) activates TCR signaling similar to that of anti-CD3 MAb, including activation of key signaling intermediates such as Lck, ZAP-70, and phospholipase C-gamma1. Moreover, the data indicate that costimulatory activity, as provided by CD28 ligation, is required for PTx to fully stimulate downstream indicators of T-cell activation such as IL-2 gene expression. By illuminating the signaling pathways that PTx activates in T cells, we provide a mechanistic understanding for how these signals deregulate immune system functions during B. pertussis infection.
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Affiliation(s)
- Olivia D Schneider
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 2256 Medical Science Building, 231 Albert Sabin Way, Cincinnati, OH 45267-0524, USA
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14
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Nakamura MM, Liew SY, Cummings CA, Brinig MM, Dieterich C, Relman DA. Growth phase- and nutrient limitation-associated transcript abundance regulation in Bordetella pertussis. Infect Immun 2006; 74:5537-48. [PMID: 16988229 PMCID: PMC1594893 DOI: 10.1128/iai.00781-06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
To survive in a host environment, microbial pathogens must sense local conditions, including nutrient availability, and adjust their growth state and virulence functions accordingly. No comprehensive investigation of growth phase-related gene regulation in Bordetella pertussis has been reported previously. We characterized changes in genome-wide transcript abundance of B. pertussis as a function of growth phase and availability of glutamate, a key nutrient for this organism. Using a Bordetella DNA microarray, we discovered significant changes in transcript abundance for 861 array elements during the transition from log phase to stationary phase, including declining transcript levels of many virulence factor genes. The responses to glutamate depletion exhibited similarities to the responses induced by exit from log phase, including decreased virulence factor transcript levels. However, only 23% of array elements that showed at least a fourfold growth phase-associated difference in transcript abundance also exhibited glutamate depletion-associated changes, suggesting that nutrient limitation may be one of several interacting factors affecting gene regulation during stationary phase. Transcript abundance patterns of a Bvg+ phase-locked mutant revealed that the BvgAS two-component regulatory system is a key determinant of growth phase- and nutrient limitation-related transcriptional control. Several adhesin genes exhibited lower transcript abundance during stationary phase and under glutamate restriction conditions. The predicted bacterial phenotype was confirmed: adherence to bronchoepithelial cells decreased 3.3- and 4.4-fold at stationary phase and with glutamate deprivation, respectively. Growth phase and nutrient availability may serve as cues by which B. pertussis regulates virulence according to the stage of infection or the location within the human airway.
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Affiliation(s)
- Mari M Nakamura
- Department of Pediatrics/Infectious Diseases, Stanford University, Stanford, California, USA
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15
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Sebaihia M, Preston A, Maskell DJ, Kuzmiak H, Connell TD, King ND, Orndorff PE, Miyamoto DM, Thomson NR, Harris D, Goble A, Lord A, Murphy L, Quail MA, Rutter S, Squares R, Squares S, Woodward J, Parkhill J, Temple LM. Comparison of the genome sequence of the poultry pathogen Bordetella avium with those of B. bronchiseptica, B. pertussis, and B. parapertussis reveals extensive diversity in surface structures associated with host interaction. J Bacteriol 2006; 188:6002-15. [PMID: 16885469 PMCID: PMC1540077 DOI: 10.1128/jb.01927-05] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bordetella avium is a pathogen of poultry and is phylogenetically distinct from Bordetella bronchiseptica, Bordetella pertussis, and Bordetella parapertussis, which are other species in the Bordetella genus that infect mammals. In order to understand the evolutionary relatedness of Bordetella species and further the understanding of pathogenesis, we obtained the complete genome sequence of B. avium strain 197N, a pathogenic strain that has been extensively studied. With 3,732,255 base pairs of DNA and 3,417 predicted coding sequences, it has the smallest genome and gene complement of the sequenced bordetellae. In this study, the presence or absence of previously reported virulence factors from B. avium was confirmed, and the genetic bases for growth characteristics were elucidated. Over 1,100 genes present in B. avium but not in B. bronchiseptica were identified, and most were predicted to encode surface or secreted proteins that are likely to define an organism adapted to the avian rather than the mammalian respiratory tracts. These include genes coding for the synthesis of a polysaccharide capsule, hemagglutinins, a type I secretion system adjacent to two very large genes for secreted proteins, and unique genes for both lipopolysaccharide and fimbrial biogenesis. Three apparently complete prophages are also present. The BvgAS virulence regulatory system appears to have polymorphisms at a poly(C) tract that is involved in phase variation in other bordetellae. A number of putative iron-regulated outer membrane proteins were predicted from the sequence, and this regulation was confirmed experimentally for five of these.
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Affiliation(s)
- Mohammed Sebaihia
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, United Kingdom
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Burns DL, Fiddner S, Cheung AM, Verma A. Analysis of subassemblies of pertussis toxin subunits in vivo and their interaction with the ptl transport apparatus. Infect Immun 2004; 72:5365-72. [PMID: 15322034 PMCID: PMC517454 DOI: 10.1128/iai.72.9.5365-5372.2004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pertussis toxin (PT) has an AB(5) structure that is typical of many bacterial protein toxins; however, this toxin is more complex than many toxins since it is composed of five different subunit types, subunits S1 to S5. Little is known about how PT assembles in vivo and how and when it interacts with its secretion apparatus, known as the Ptl transporter. In order to better understand these events, we expressed subsets of the genes encoding the S1, S2, and/or S4 subunits of PT in strains of Bordetella pertussis that either did or did not produce the Ptl proteins. We found evidence to suggest that certain subassemblies of the toxin, including subassemblies consisting of the S1 subunit and incomplete forms of the B oligomer, can form in vivo, at least transiently. These results suggest that the B oligomer of the toxin does not need to completely form before interactions between the S1 subunit and B-oligomer subunits can occur in vivo. All subassemblies localized primarily to the membrane fraction of the cell. Moreover, we found that Ptl-mediated secretion occurs in a strain that produces S1 and an incomplete complement of B-oligomer subunits. These results indicate that subassemblies of the toxin consisting of the S1 subunit and a partial B oligomer can interact with the Ptl system.
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Affiliation(s)
- Drusilla L Burns
- Laboratory of Respiratory and Special Pathogens, Food and Drug Administration, Bethesda, Maryland, USA.
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