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Jones RA, Jerse AE, Tang CM. Gonococcal PorB: a multifaceted modulator of host immune responses. Trends Microbiol 2024; 32:355-364. [PMID: 37891023 DOI: 10.1016/j.tim.2023.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023]
Abstract
Neisseria gonorrhoeae is a human-specific pathogen responsible for the sexually transmitted infection, gonorrhoea. N. gonorrhoeae promotes its survival by manipulating both innate and adaptive immune responses. The most abundant gonococcal outer-membrane protein is PorB, an essential porin that facilitates ion exchange. Importantly, gonococcal PorB has several immunomodulatory properties. To subvert the innate immune response, PorB suppresses killing mechanisms of macrophages and neutrophils, and recruits negative regulators of complement to the gonococcal cell surface. For manipulation of adaptive immune responses, gonococcal PorB suppresses the capability of dendritic cells to stimulate proliferation of T cells. As gonococcal PorB is highly abundant in outer-membrane vesicles, consideration of the immunomodulatory properties of this porin is critical when designing gonococcal vaccines.
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Affiliation(s)
- Rebekah A Jones
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Ann E Jerse
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, USA
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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2
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Ball LM, Bronstein E, Liechti GW, Maurelli AT. Neisseria gonorrhoeae drives Chlamydia trachomatis into a persistence-like state during in vitro co-infection. Infect Immun 2024; 92:e0017923. [PMID: 38014981 PMCID: PMC10790821 DOI: 10.1128/iai.00179-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 11/05/2023] [Indexed: 11/29/2023] Open
Abstract
Chlamydia trachomatis and Neisseria gonorrhoeae are the most prevalent bacterial sexually transmitted infections (STIs) globally. Despite frequent co-infections in patients, few studies have investigated how mono-infections may differ from co-infections. We hypothesized that a symbiotic relationship between the pathogens could account for the high rates of clinical co-infection. During in vitro co-infection, we observed an unexpected phenotype where the C. trachomatis developmental cycle was impaired by N. gonorrhoeae. C. trachomatis is an obligate intracellular pathogen with a unique biphasic developmental cycle progressing from infectious elementary bodies (EB) to replicative reticulate bodies (RB), and back. After 12 hours of co-infection, we observed fewer EBs than in a mono-infection. Chlamydial genome copy number remained equivalent between mono- and co-infections. This is a hallmark of Chlamydial persistence. Chlamydial persistence alters inclusion morphology but varies depending on the stimulus/stress. We observed larger, but fewer, Chlamydia during co-infection. Tryptophan depletion can induce Chlamydial persistence, but tryptophan supplementation did not reverse the co-infection phenotype. Only viable and actively growing N. gonorrhoeae produced the inhibition phenotype in C. trachomatis. Piliated N. gonorrhoeae had the strongest effect on C. trachomatis, but hyperpiliated or non-piliated N. gonorrhoeae still produced the phenotype. EB development was modestly impaired when N. gonorrhoeae were grown in transwells above the infected monolayer. C. trachomatis serovar L2 was not impaired during co-infection. Chlamydial impairment could be due to cytoskeletal or osmotic stress caused by an as-yet-undefined mechanism. We conclude that N. gonorrhoeae induces a persistence-like state in C. trachomatis that is serovar dependent.
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Affiliation(s)
- Louise M. Ball
- Emerging Pathogens Institute and Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - Ellis Bronstein
- F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - George W. Liechti
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - Anthony T. Maurelli
- Emerging Pathogens Institute and Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
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3
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Heydarian M, Rühl E, Rawal R, Kozjak-Pavlovic V. Tissue Models for Neisseria gonorrhoeae Research—From 2D to 3D. Front Cell Infect Microbiol 2022; 12:840122. [PMID: 35223556 PMCID: PMC8873371 DOI: 10.3389/fcimb.2022.840122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 12/02/2022] Open
Abstract
Neisseria gonorrhoeae is a human-specific pathogen that causes gonorrhea, the second most common sexually transmitted infection worldwide. Disease progression, drug discovery, and basic host-pathogen interactions are studied using different approaches, which rely on models ranging from 2D cell culture to complex 3D tissues and animals. In this review, we discuss the models used in N. gonorrhoeae research. We address both in vivo (animal) and in vitro cell culture models, discussing the pros and cons of each and outlining the recent advancements in the field of three-dimensional tissue models. From simple 2D monoculture to complex advanced 3D tissue models, we provide an overview of the relevant methodology and its application. Finally, we discuss future directions in the exciting field of 3D tissue models and how they can be applied for studying the interaction of N. gonorrhoeae with host cells under conditions closely resembling those found at the native sites of infection.
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Lujan AL, Croci DO, Rabinovich GA, Damiani MT. Galectins as potential therapeutic targets in STIs in the female genital tract. Nat Rev Urol 2022; 19:240-252. [PMID: 35105978 DOI: 10.1038/s41585-021-00562-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 12/12/2022]
Abstract
Every day, more than one million people worldwide acquire a sexually transmitted infection (STI). This public health problem has a direct effect on women's reproductive and sexual health as STIs can cause irreversible damage to fertility and can have negative consequences associated with discrimination and social exclusion. Infection with one sexually transmitted pathogen predisposes to co-infection with others, suggesting the existence of shared pathways that serve as molecular links between these diseases. Galectins, a family of β-galactoside-binding proteins, have emerged as endogenous mediators that facilitate cell-surface binding, internalization and cell invasion of many sexually transmitted pathogens, including Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Candida albicans, HIV and herpes simplex virus. The ability of certain galectins to dimerize or form multimeric complexes confers the capacity to interact simultaneously with glycosylated ligands on both the pathogen and the cervico-vaginal tissue on these proteins. Galectins can act as a bridge by engaging glycans from the pathogen surface and glycosylated receptors from host cells, which is a mechanism that has been shown to be shared by several sexually transmitted pathogens. In the case of viruses and obligate intracellular bacteria, binding to the cell surface promotes pathogen internalization and cell invasion. Inflammatory responses that occur in cervico-vaginal tissue might trigger secretion of galectins, which in turn control the establishment, evolution and severity of STIs. Thus, galectin-targeted therapies could potentially prevent or decrease STIs caused by a diverse array of pathogenic microorganisms; furthermore, anti-galectin agents might reduce treatment costs of STIs and reach the most vulnerable populations.
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Affiliation(s)
- Agustin L Lujan
- Laboratorio de Bioquímica e Inmunidad, Instituto de Bioquímica y Biotecnología, Facultad de Ciencias Médicas, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU), Universidad Nacional de Cuyo (UNCUYO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina.,Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Diego O Croci
- Laboratorio de Inmunopatología, Facultad de Ciencias Exactas y Naturales, Instituto de Histología y Embriología de Mendoza (IHEM), Universidad Nacional de Cuyo (UNCUYO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
| | - Gabriel A Rabinovich
- Laboratorio de Glicomedicina, Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina. .,Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (UBA), C1428AGE, Buenos Aires, Argentina.
| | - Maria T Damiani
- Laboratorio de Bioquímica e Inmunidad, Instituto de Bioquímica y Biotecnología, Facultad de Ciencias Médicas, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU), Universidad Nacional de Cuyo (UNCUYO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina.
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5
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Ivanov SS, Castore R, Juarez Rodriguez MD, Circu M, Dragoi AM. Neisseria gonorrhoeae subverts formin-dependent actin polymerization to colonize human macrophages. PLoS Pathog 2021; 17:e1010184. [PMID: 34962968 PMCID: PMC8746766 DOI: 10.1371/journal.ppat.1010184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 01/10/2022] [Accepted: 12/09/2021] [Indexed: 12/16/2022] Open
Abstract
Dynamic reorganization of the actin cytoskeleton dictates plasma membrane morphogenesis and is frequently subverted by bacterial pathogens for entry and colonization of host cells. The human-adapted bacterial pathogen Neisseria gonorrhoeae can colonize and replicate when cultured with human macrophages, however the basic understanding of how this process occurs is incomplete. N. gonorrhoeae is the etiological agent of the sexually transmitted disease gonorrhea and tissue resident macrophages are present in the urogenital mucosa, which is colonized by the bacteria. We uncovered that when gonococci colonize macrophages, they can establish an intracellular or a cell surface-associated niche that support bacterial replication independently. Unlike other intracellular bacterial pathogens, which enter host cells as single bacterium, establish an intracellular niche and then replicate, gonococci invade human macrophages as a colony. Individual diplococci are rapidly phagocytosed by macrophages and transported to lysosomes for degradation. However, we found that surface-associated gonococcal colonies of various sizes can invade macrophages by triggering actin skeleton rearrangement resulting in plasma membrane invaginations that slowly engulf the colony. The resulting intracellular membrane-bound organelle supports robust bacterial replication. The gonococci-occupied vacuoles evaded fusion with the endosomal compartment and were enveloped by a network of actin filaments. We demonstrate that gonococcal colonies invade macrophages via a process mechanistically distinct from phagocytosis that is regulated by the actin nucleating factor FMNL3 and is independent of the Arp2/3 complex. Our work provides insights into the gonococci life-cycle in association with human macrophages and defines key host determinants for macrophage colonization. During infection, the human-adapted bacterial pathogen Neisseria gonorrhoeae and causative agent of gonorrhea can invade the submucosa of the urogenital tract where it encounters tissue-resident innate immune sentinels, such as macrophages and neutrophils. Instead of eliminating gonococci, macrophages support robust bacterial replication. Here, we detail the life cycle of N. gonorrhoeae in association with macrophages and define key regulators that govern the colonization processes. We uncovered that N. gonorrhoeae establishes two distinct subcellular niches that support bacterial replication autonomously–one niche was on the macrophage surface and another one was intracellular. Gonococci subverted the host actin cytoskeleton through the actin nucleating factor FMNL3 to invade colonized macrophages and occupy a membrane-bound intracellular organelle. We propose that N. gonorrhoeae ability to occupy distinct subcellular niches when colonizing macrophages likely confers broad protection against multiple host defense responses.
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Affiliation(s)
- Stanimir S. Ivanov
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
- * E-mail: (SSI); (AMD)
| | - Reneau Castore
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
| | - Maria Dolores Juarez Rodriguez
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
| | - Magdalena Circu
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
| | - Ana-Maria Dragoi
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center—Shreveport, Shreveport, Louisiana, United States of America
- * E-mail: (SSI); (AMD)
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6
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Peak IR, Chen A, Jen FEC, Jennings C, Schulz BL, Saunders NJ, Khan A, Seifert HS, Jennings MP. Neisseria meningitidis Lacking the Major Porins PorA and PorB Is Viable and Modulates Apoptosis and the Oxidative Burst of Neutrophils. J Proteome Res 2016; 15:2356-65. [PMID: 26562068 DOI: 10.1021/acs.jproteome.5b00938] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The bacterial pathogen Neisseria meningitidis expresses two major outer-membrane porins. PorA expression is subject to phase-variation (high frequency, random, on-off switching), and both PorA and PorB are antigenically variable between strains. PorA expression is variable and not correlated with meningococcal colonisation or invasive disease, whereas all naturally-occurring strains express PorB suggesting strong selection for expression. We have generated N. meningitidis strains lacking expression of both major porins, demonstrating that they are dispensable for bacterial growth in vitro. The porAB mutant strain has an exponential growth rate similar to the parental strain, as do the single porA or porB mutants, but the porAB mutant strain does not reach the same cell density in stationary phase. Proteomic analysis suggests that the double mutant strain exhibits compensatory expression changes in proteins associated with cellular redox state, energy/nutrient metabolism, and membrane stability. On solid media, there is obvious growth impairment that is rescued by addition of blood or serum from mammalian species, particularly heme. These porin mutants are not impaired in their capacity to inhibit both staurosporine-induced apoptosis and a phorbol 12-myristate 13-acetate-induced oxidative burst in human neutrophils suggesting that the porins are not the only bacterial factors that can modulate these processes in host cells.
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Affiliation(s)
- Ian R Peak
- School of Medical Science, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia.,Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Adrienne Chen
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University , 303 East Chicago Avenue, Chicago, Illinois 60611, United States
| | - Freda E-C Jen
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Courtney Jennings
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Benjamin L Schulz
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland , St. Lucia, Brisbane, QLD 4072, Australia
| | - Nigel J Saunders
- Centre for Systems and Synthetic Biology, Brunel University , Uxbridge, Middlesex UB8 3PH, U.K
| | - Arshad Khan
- Centre for Systems and Synthetic Biology, Brunel University , Uxbridge, Middlesex UB8 3PH, U.K
| | - H Steven Seifert
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University , 303 East Chicago Avenue, Chicago, Illinois 60611, United States
| | - Michael P Jennings
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
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7
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Toussi DN, Wetzler LM, Liu X, Massari P. Neisseriae internalization by epithelial cells is enhanced by TLR2 stimulation. Microbes Infect 2016; 18:627-638. [PMID: 27373686 DOI: 10.1016/j.micinf.2016.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/23/2022]
Abstract
Neisseria meningitidis (NM) is an opportunistic gram-negative human pathogen that colonizes the human nasopharyngeal epithelium. Asymptomatic carriage is common, but some meningococcal strains can invade nasopharyngeal epithelial cells and proceed to cause severe and often fatal infections. Invasion is predominantly driven by expression of bacterial virulence factors and host cell cognate receptors for bacterial recognition. Porins are among the Neisserial components involved in host cell activation and bacterial internalization processes. Similar to other virulence factors, porins present antigenic and structure variability among strains. Such sequence variability in the surface-exposed loop regions has been correlated to bacterial invasiveness and to variability in host cell responses via Toll-like receptor 2 (TLR2). Here, we examined whether TLR2 signaling by porins influences recovery of intracellular Neisseriae from epithelial cells in vitro. Our results show that TLR2 stimulation, either by the organism or exogenously, generally enhances Neisseriae internalization by epithelial cells. TLR2-driven intracellular signaling via ERK1/2, JNK and particularly NF-κB plays a role in this process. Based on these results, it is possible that expression of porin sequence variants that strongly induce TLR2 activation may be a mechanism to enhance the invasive features of pathogenic Neisseriae strains.
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Affiliation(s)
- Deana N Toussi
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, EBRC, 650 Albany Street, Boston, MA 02118, USA; Novartis Companion Diagnostics, 45 Sidney Street, Cambridge, MA 02139, USA
| | - Lee M Wetzler
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, EBRC, 650 Albany Street, Boston, MA 02118, USA
| | - Xiuping Liu
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, EBRC, 650 Albany Street, Boston, MA 02118, USA
| | - Paola Massari
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, EBRC, 650 Albany Street, Boston, MA 02118, USA; Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Jaharis 501b, 150 Harrison Avenue, Boston, MA 02111, USA.
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8
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Stefanelli P, Neri A, Tanabe M, Fazio C, Massari P. Typing and surface charges of the variable loop regions of PorB from Neisseria meningitidis. IUBMB Life 2016; 68:488-95. [PMID: 27156582 DOI: 10.1002/iub.1508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/15/2016] [Indexed: 12/16/2022]
Abstract
PorB is a pan-Neisserial major outer membrane protein with a trimeric β-barrel structure. Each monomer presents eight periplasmic turns and eight surface exposed loop regions with sequence variability. PorB induces activation of host cell responses via a TLR2-dependent mechanism likely mediated by electrostatic interactions between TLR2 and PorB surface exposed loops. Variability in the loop amino acid sequence is known to influence cell responses to PorB in vitro, particularly for the residues in L5 and L7. In this work, the sequence of the porB gene and the electrostatic surface charges of PorB from 35 invasive meningococcal isolates belonging to the main clonal complexes identified in Italy and from five carriage genomes available on the website http://pubmlst.org/neisseria/ were examined. Analysis of the porB encoding regions from the invasive meningococci has identified four new alleles and a potential association between porB alleles, serogroup, and clonal complexes. Through computer-based modeling and analysis of the electrostatic surface charges of PorB from these strains, loop charge segregation between PorB from invasive serogroups B and C was observed. Specifically, loops 1, 4, and 7 were negatively charged and L2 and L8 were mostly neutral in serogroup B isolates, while an overall homogeneous positive surface charge was present in PorB from invasive serogroup C strains. A higher PorB sequence variability was observed among carriage genomes, and a general prevalence of negative loop surface charges. The surface charge differences in PorB from serogroups B and C invasive and carriage strains may, in part, influence the outcomes of Neisseriae interactions with host cells. © 2016 IUBMB Life, 68(6):488-495, 2016.
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Affiliation(s)
- Paola Stefanelli
- Department of Infectious, Parasitic & Immuno-Mediated Diseases, Istituto Superiore Di Sanità, Rome, Italy
| | - Arianna Neri
- Department of Infectious, Parasitic & Immuno-Mediated Diseases, Istituto Superiore Di Sanità, Rome, Italy
| | - Mikio Tanabe
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - Cecilia Fazio
- Department of Infectious, Parasitic & Immuno-Mediated Diseases, Istituto Superiore Di Sanità, Rome, Italy
| | - Paola Massari
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, MA, USA
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Inhibitory mechanism of butylated hydroxyanisole against infection of Fusarium proliferatum based on comparative proteomic analysis. J Proteomics 2016; 148:1-11. [PMID: 27169933 DOI: 10.1016/j.jprot.2016.04.051] [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: 02/20/2016] [Revised: 04/13/2016] [Accepted: 04/26/2016] [Indexed: 01/19/2023]
Abstract
UNLABELLED Fusarium proliferatum as a filamentous fungal pathogen can produce mycotoxins that can contaminate postharvest fruits and thus impact risks on human health. The extracellular proteomes of F. proliferatum grown in the absence and presence of butylated hydroxyanisole (BHA) were analyzed comparatively. A total of 66 significantly different expressed secreted proteins were identified by LC-ESI-MS/MS analysis. The BHA treatment suppressed the accumulation of some pathogenic factors such as aspartic protease, cell wall degradation enzymes, porin, superoxide dismutase and glyceraldehyde-3-phosphate dehydrogenase. On the contrary, the BHA treatment increased the abundances of some proteins, such as ATP binding cassette transporter substrate-binding protein and lipopolysaccharide-assembly lipoprotein, involved in the growth of F. proliferatum. These findings suggest that BHA treatment could influence the pathogenic ability of F. proliferatum via inhibiting the levels of virulence factors and cell wall degradation-associated enzymes. Moreover, the induction of the growth-related proteins after the BHA treatment suggests that the livelihood of F. proliferatum might depend on the cost of reduced pathogenic ability. This study has provided some evidence for understanding the complicated mechanisms of F. proliferatum infection in an effort to develop new targets for the control of this fungal pathogen. BIOLOGICAL SIGNIFICANCE To better understand the inhibitory mechanism of F. proliferatum by butylated hydroxyanisole (BHA) treatment, a comprehensive proteomic analysis of the secreted proteins of F. proliferatum was firstly conducted. Among the 66 identified spots, 34 and 32 proteins were down- and up-accumulated significantly by BHA treatment, respectively. Many of the identified key protein species were involved in the pathogenic ability and the growth of F. proliferatum. This study is helpful for broadening our knowledge of the pathogenic mechanism of F. proliferatum.
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Faulstich M, Hagen F, Avota E, Kozjak-Pavlovic V, Winkler AC, Xian Y, Schneider-Schaulies S, Rudel T. Neutral sphingomyelinase 2 is a key factor for PorB-dependent invasion of Neisseria gonorrhoeae. Cell Microbiol 2014; 17:241-53. [PMID: 25224994 DOI: 10.1111/cmi.12361] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 12/25/2022]
Abstract
Disseminated gonococcal infection (DGI) is a rare but serious complication caused by the spread of Neisseria gonorrhoeae in the human host. Gonococci associated with DGI mainly express the outer membrane protein PorBIA that binds to the scavenger receptor expressed on endothelial cells (SREC-I) and mediates bacterial uptake. We recently demonstrated that this interaction relies on intact membrane rafts that acquire SREC-I upon attachment of gonococci and initiates the signalling cascade that finally leads to the uptake of gonococci in epithelial cells. In this study, we analysed the role of sphingomyelinases and their breakdown product ceramide. Gonococcal infection induced increased levels of ceramide that was enriched at bacterial attachment sites. Interestingly, neutral but not acid sphingomyelinase was mandatory for PorBIA -mediated invasion into host cells. Neutral sphingomyelinase was required to recruit the PI3 kinase to caveolin and thereby activates the PI3 kinase-dependent downstream signalling leading to bacterial uptake. Thus, this study elucidates the initial signalling processes of bacterial invasion during DGI and demonstrates a novel role for neutral sphingomyelinase in the course of bacterial infections.
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Affiliation(s)
- Michaela Faulstich
- Department of Microbiology, University of Würzburg Biocenter, Würzburg, Germany
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11
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Remmele CW, Xian Y, Albrecht M, Faulstich M, Fraunholz M, Heinrichs E, Dittrich MT, Müller T, Reinhardt R, Rudel T. Transcriptional landscape and essential genes of Neisseria gonorrhoeae. Nucleic Acids Res 2014; 42:10579-95. [PMID: 25143534 PMCID: PMC4176332 DOI: 10.1093/nar/gku762] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 02/06/2023] Open
Abstract
The WHO has recently classified Neisseria gonorrhoeae as a super-bacterium due to the rapid spread of antibiotic resistant derivatives and an overall dramatic increase in infection incidences. Genome sequencing has identified potential genes, however, little is known about the transcriptional organization and the presence of non-coding RNAs in gonococci. We performed RNA sequencing to define the transcriptome and the transcriptional start sites of all gonococcal genes and operons. Numerous new transcripts including 253 potentially non-coding RNAs transcribed from intergenic regions or antisense to coding genes were identified. Strikingly, strong antisense transcription was detected for the phase-variable opa genes coding for a family of adhesins and invasins in pathogenic Neisseria, that may have regulatory functions. Based on the defined transcriptional start sites, promoter motifs were identified. We further generated and sequenced a high density Tn5 transposon library to predict a core of 827 gonococcal essential genes, 133 of which have no known function. Our combined RNA-Seq and Tn-Seq approach establishes a detailed map of gonococcal genes and defines the first core set of essential gonococcal genes.
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Affiliation(s)
- Christian W Remmele
- Department of Bioinformatics, University of Würzburg, 97074 Würzburg, Germany
| | - Yibo Xian
- Department of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | - Marco Albrecht
- Department of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | - Michaela Faulstich
- Department of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | - Martin Fraunholz
- Department of Microbiology, University of Würzburg, 97074 Würzburg, Germany
| | | | - Marcus T Dittrich
- Department of Bioinformatics, University of Würzburg, 97074 Würzburg, Germany
| | - Tobias Müller
- Department of Bioinformatics, University of Würzburg, 97074 Würzburg, Germany
| | - Richard Reinhardt
- Max Planck-Genome-centre Cologne at MPI for Plant Breeding Research, 50829 Cologne, Germany
| | - Thomas Rudel
- Department of Microbiology, University of Würzburg, 97074 Würzburg, Germany
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12
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Saturating mutagenesis of an essential gene: a majority of the Neisseria gonorrhoeae major outer membrane porin (PorB) is mutable. J Bacteriol 2013; 196:540-7. [PMID: 24244002 DOI: 10.1128/jb.01073-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The major outer membrane porin (PorB) of Neisseria gonorrhoeae is an essential protein that mediates ion exchange between the organism and its environment and also plays multiple roles in human host pathogenesis. To facilitate structure-function studies of porin's multiple roles, we performed saturating mutagenesis at the porB locus and used deep sequencing to identify essential versus mutable residues. Random mutations in porB were generated in a plasmid vector, and mutant gene pools were transformed into N. gonorrhoeae to select for alleles that maintained bacterial viability. Deep sequencing of the input plasmid pools and the output N. gonorrhoeae genomic DNA pools identified mutations present in each, and the mutations in both pools were compared to determine which changes could be tolerated by the organism. We examined the mutability of 328 amino acids in the mature PorB protein and found that 308 of them were likely to be mutable and that 20 amino acids were likely to be nonmutable. A subset of these predictions was validated experimentally. This approach to identifying essential amino acids in a protein of interest introduces an additional application for next-generation sequencing technology and provides a template for future studies of both porin and other essential bacterial genes.
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Structure-function studies of the Neisseria gonorrhoeae major outer membrane porin. Infect Immun 2013; 81:4383-91. [PMID: 24042111 DOI: 10.1128/iai.00367-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The major outer membrane porin (PorB) expressed by Neisseria gonorrhoeae plays multiple roles during infection, in addition to its function as an outer membrane pore. We have generated a panel of mutants of N. gonorrhoeae strain FA1090 expressing a variety of mutant porB genes that all function as porins. We identified multiple regions of porin that are involved in its binding to the complement regulatory factors C4b-binding protein and factor H and confirmed that the ability to bind at least one factor is required for FA1090 to survive the bactericidal effects of human serum. We tested the ability of these mutants to inhibit both apoptosis and the oxidative burst in polymorphonuclear leukocytes but were unable to identify the porin domains required for either function. This study has identified nonessential porin domains and some potentially essential portions of the protein and has further expanded our understanding of the contribution of the porin domains required for complement regulation.
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Crook MB, Draper AL, Guillory RJ, Griffitts JS. The Sinorhizobium meliloti essential porin RopA1 is a target for numerous bacteriophages. J Bacteriol 2013; 195:3663-71. [PMID: 23749981 PMCID: PMC3754576 DOI: 10.1128/jb.00480-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 06/05/2013] [Indexed: 01/21/2023] Open
Abstract
The symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti harbors a gene, SMc02396, which encodes a predicted outer membrane porin that is conserved in many symbiotic and pathogenic bacteria in the order Rhizobiales. Here, this gene (renamed ropA1) is shown to be required for infection by two commonly utilized transducing bacteriophages (ΦM12 and N3). Mapping of S. meliloti mutations conferring resistance to ΦM12, N3, or both phages simultaneously revealed diverse mutations mapping within the ropA1 open reading frame. Subsequent tests determined that RopA1, lipopolysaccharide, or both are required for infection by all of a larger collection of Sinorhizobium-specific phages. Failed attempts to disrupt or delete ropA1 suggest that this gene is essential for viability. Phylogenetic analysis reveals that ropA1 homologs in many Rhizobiales species are often found as two genetically linked copies and that the intraspecies duplicates are always more closely related to each other than to homologs in other species, suggesting multiple independent duplication events.
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Affiliation(s)
- Matthew B Crook
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, Utah, USA
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Faulstich M, Böttcher JP, Meyer TF, Fraunholz M, Rudel T. Pilus phase variation switches gonococcal adherence to invasion by caveolin-1-dependent host cell signaling. PLoS Pathog 2013; 9:e1003373. [PMID: 23717204 PMCID: PMC3662692 DOI: 10.1371/journal.ppat.1003373] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 04/05/2013] [Indexed: 02/08/2023] Open
Abstract
Many pathogenic bacteria cause local infections but occasionally invade into the blood stream, often with fatal outcome. Very little is known about the mechanism underlying the switch from local to invasive infection. In the case of Neisseria gonorrhoeae, phase variable type 4 pili (T4P) stabilize local infection by mediating microcolony formation and inducing anti-invasive signals. Outer membrane porin PorB(IA), in contrast, is associated with disseminated infection and facilitates the efficient invasion of gonococci into host cells. Here we demonstrate that loss of pili by natural pilus phase variation is a prerequisite for the transition from local to invasive infection. Unexpectedly, both T4P-mediated inhibition of invasion and PorB(IA)-triggered invasion utilize membrane rafts and signaling pathways that depend on caveolin-1-Y14 phosphorylation (Cav1-pY14). We identified p85 regulatory subunit of PI3 kinase (PI3K) and phospholipase Cγ1 as new, exclusive and essential interaction partners for Cav1-pY14 in the course of PorBIA-induced invasion. Active PI3K induces the uptake of gonococci via a new invasion pathway involving protein kinase D1. Our data describe a novel route of bacterial entry into epithelial cells and offer the first mechanistic insight into the switch from local to invasive gonococcal infection.
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Affiliation(s)
- Michaela Faulstich
- Chair of Microbiology, University of Würzburg Biocenter, Würzburg, Germany
| | - Jan-Peter Böttcher
- Max Planck Institute for Infection Biology, Dept. Molecular Biology, Berlin, Germany
| | - Thomas F. Meyer
- Max Planck Institute for Infection Biology, Dept. Molecular Biology, Berlin, Germany
| | - Martin Fraunholz
- Chair of Microbiology, University of Würzburg Biocenter, Würzburg, Germany
| | - Thomas Rudel
- Chair of Microbiology, University of Würzburg Biocenter, Würzburg, Germany
- * E-mail:
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Abstract
The outer membrane of Gram-negative bacteria contains a large number of channel-forming proteins, porins, for the uptake of small nutrient molecules. Neisseria gonorrhoeae PorBIA (PorB of serotype A) are associated with disseminating diseases and mediate a rapid bacterial invasion into host cells in a phosphate-sensitive manner. To gain insights into this structure-function relationship we analysed PorBIA by X-ray crystallography in the presence of phosphate and ATP. The structure of PorBIA in the complex solved at a resolution of 3.3 Å (1 Å=0.1 nm) displays a surplus of positive charges inside the channel. ATP ligand-binding in the channel is co-ordinated by the positively charged residues of the channel interior. These residues ligate the aromatic, sugar and pyrophosphate moieties of the ligand. Two phosphate ions were observed in the structure, one of which clamped by two arginine residues (Arg92 and Arg124) localized at the extraplasmic channel exit. A short β-bulge in β2-strand together with the long L3 loop narrow the barrel diameter significantly and further support substrate specificity through hydrogen bond interactions. Interestingly the structure also comprised a small peptide as a remnant of a periplasmic protein which physically links porin molecules to the peptidoglycan network. To test the importance of Arg92 on bacterial invasion the residue was mutated. In vivo assays of bacteria carrying a R92S mutation confirmed the importance of this residue for host-cell invasion. Furthermore systematic sequence and structure comparisons of PorBIA from Neisseriaceae indicated Arg92 to be unique in disseminating N. gonorrhoeae thereby possibly distinguishing invasion-promoting porins from other neisserial porins.
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Neisseria meningitidis serogroup B vaccine development. Microb Pathog 2013; 57:33-40. [PMID: 23416222 DOI: 10.1016/j.micpath.2013.02.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 02/04/2013] [Indexed: 11/22/2022]
Abstract
Neisseria meningitidis is an air-borne, gram-negative pathogen that actively invades its human host leading to the development of life-threatening pathologies. As one of the leading causes of death in the world, during an epidemic period N. meningitidis can be responsible for nearly 1000 new infections per 100,000 individuals. The bacterial species is further categorized into 13 serotypes, with five, A, B, C, W-135, and Y, being the most clinically relevant, causing the overwhelming majority of diseases. There are two contemporary, purified protein conjugate vaccines available that function by targeting serogroups A, C, W-135, and Y. Historically, serogroup B has posed a vaccination challenge; however, there are currently two vaccines in development able to target serotype B. This review will highlight N. meningitidis as a pathogen and explore the recent literature providing a current review of meningococcal vaccination development.
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Neisseria gonorrhoeae-mediated inhibition of apoptotic signalling in polymorphonuclear leukocytes. Infect Immun 2011; 79:4447-58. [PMID: 21844239 DOI: 10.1128/iai.01267-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The human pathogen Neisseria gonorrhoeae recruits and interacts extensively with polymorphonuclear leukocytes (PMNs) during infection. N. gonorrhoeae is able to survive the bactericidal activity of these innate immune cells and can actively modulate PMN functions in vitro. PMNs are short-lived cells which readily undergo apoptosis, and thus the effect of N. gonorrhoeae infection on PMN survival has implications for whether PMNs might serve as an important site of bacterial replication during infection. We developed and validated an HL-60 myeloid leukemia cell culture model for PMN infection and used both these cells and primary PMNs to show that N. gonorrhoeae infection alone does not induce apoptosis and furthermore that N. gonorrhoeae can inhibit both spontaneous apoptosis and apoptosis induced by the intrinsic and extrinsic apoptosis inducers staurosporine (STS) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), respectively. N. gonorrhoeae infection also results in the activation of NF-κB signaling in neutrophils and induces secretion of an identical profile of proinflammatory cytokines and chemokines in both HL-60 cells and primary PMNs. Our data show that the HL-60 cell line can be used to effectively model N. gonorrhoeae-PMN interactions and that N. gonorrhoeae actively inhibits apoptosis induced by multiple stimuli to prolong PMN survival and potentially facilitate bacterial survival, replication, and transmission.
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Johnson MB, Criss AK. Resistance of Neisseria gonorrhoeae to neutrophils. Front Microbiol 2011; 2:77. [PMID: 21747795 PMCID: PMC3128980 DOI: 10.3389/fmicb.2011.00077] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/31/2011] [Indexed: 01/04/2023] Open
Abstract
Infection with the human-specific bacterial pathogen Neisseria gonorrhoeae triggers a potent, local inflammatory response driven by polymorphonuclear leukocytes (neutrophils or PMNs). PMNs are terminally differentiated phagocytic cells that are a vital component of the host innate immune response and are the first responders to bacterial and fungal infections. PMNs possess a diverse arsenal of components to combat microorganisms, including the production of reactive oxygen species and release of degradative enzymes and antimicrobial peptides. Despite numerous PMNs at the site of gonococcal infection, N. gonorrhoeae can be cultured from the PMN-rich exudates of individuals with acute gonorrhea, indicating that some bacteria resist killing by neutrophils. The contribution of PMNs to gonorrheal pathogenesis has been modeled in vivo by human male urethral challenge and murine female genital inoculation and in vitro using isolated primary PMNs or PMN-derived cell lines. These systems reveal that some gonococci survive and replicate within PMNs and suggest that gonococci defend themselves against PMNs in two ways: they express virulence factors that defend against PMNs' oxidative and non-oxidative antimicrobial components, and they modulate the ability of PMNs to phagocytose gonococci and to release antimicrobial components. In this review, we will highlight the varied and complementary approaches used by N. gonorrhoeae to resist clearance by human PMNs, with an emphasis on gonococcal gene products that modulate bacterial-PMN interactions. Understanding how some gonococci survive exposure to PMNs will help guide future initiatives for combating gonorrheal disease.
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Affiliation(s)
| | - Alison K. Criss
- Department of Microbiology, University of VirginiaCharlottesville, VA, USA
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Meningococcal internalization into human endothelial and epithelial cells is triggered by the influx of extracellular L-glutamate via GltT L-glutamate ABC transporter in Neisseria meningitidis. Infect Immun 2010; 79:380-92. [PMID: 20956569 DOI: 10.1128/iai.00497-10] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Meningococcal internalization into human cells is likely to be a consequence of meningococcal adhesion to human epithelial and endothelial cells. Here, we identified three transposon mutants of Neisseria meningitidis that were primarily defective in the internalization of human brain microvascular endothelial cells (HBMEC), with insertions occurring in the gltT (a sodium-independent L-glutamate transporter) gene or its neighboring gene, NMB1964 (unknown function). NMB1964 was tentatively named gltM in this study because of the presence of a mammalian cell entry (MCE)-related domain in the deduced amino acid sequences. The null ΔgltT-ΔgltM N. meningitidis mutant was also defective in the internalization into human umbilical vein endothelial cells and the human lung carcinoma epithelial cell line A549, and the defect was suppressed by transcomplementation of the mutants with gltT(+)-gltM(+) genes. The intracellular survival of the ΔgltT-ΔgltM mutant in HBMEC was not largely different from that of the wild-type strain under our experimental conditions. Introduction of a1-bp deletion and amber or ochre mutations in gltT-gltM genes resulted in the loss of efficient internalization into HBMEC. The defect in meningococcal internalization into HBMEC and L-glutamate uptake in the ΔgltT-ΔgltM mutant were suppressed only in strains expressing both GltT and GltM proteins. The efficiency of meningococcal invasion to HBMEC decreased under L-glutamate-depleted conditions. Furthermore, ezrin, a key membrane-cytoskeleton linker, accumulated beneath colonies of the gltT(+)-gltM(+) N. meningitidis strain but not of the ΔgltT-ΔgltM mutant. These findings suggest that l-glutamate influx via the GltT-GltM L-glutamate ABC transporter serves as a cue for N. meningitidis internalization into host cells.
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Genome sequencing reveals widespread virulence gene exchange among human Neisseria species. PLoS One 2010; 5:e11835. [PMID: 20676376 PMCID: PMC2911385 DOI: 10.1371/journal.pone.0011835] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 06/01/2010] [Indexed: 11/19/2022] Open
Abstract
Commensal bacteria comprise a large part of the microbial world, playing important roles in human development, health and disease. However, little is known about the genomic content of commensals or how related they are to their pathogenic counterparts. The genus Neisseria, containing both commensal and pathogenic species, provides an excellent opportunity to study these issues. We undertook a comprehensive sequencing and analysis of human commensal and pathogenic Neisseria genomes. Commensals have an extensive repertoire of virulence alleles, a large fraction of which has been exchanged among Neisseria species. Commensals also have the genetic capacity to donate DNA to, and take up DNA from, other Neisseria. Our findings strongly suggest that commensal Neisseria serve as reservoirs of virulence alleles, and that they engage extensively in genetic exchange.
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Kozjak-Pavlovic V, Dian-Lothrop EA, Meinecke M, Kepp O, Ross K, Rajalingam K, Harsman A, Hauf E, Brinkmann V, Günther D, Herrmann I, Hurwitz R, Rassow J, Wagner R, Rudel T. Bacterial porin disrupts mitochondrial membrane potential and sensitizes host cells to apoptosis. PLoS Pathog 2009; 5:e1000629. [PMID: 19851451 PMCID: PMC2759283 DOI: 10.1371/journal.ppat.1000629] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 09/24/2009] [Indexed: 11/28/2022] Open
Abstract
The bacterial PorB porin, an ATP-binding β-barrel protein of pathogenic Neisseria gonorrhoeae, triggers host cell apoptosis by an unknown mechanism. PorB is targeted to and imported by host cell mitochondria, causing the breakdown of the mitochondrial membrane potential (ΔΨm). Here, we show that PorB induces the condensation of the mitochondrial matrix and the loss of cristae structures, sensitizing cells to the induction of apoptosis via signaling pathways activated by BH3-only proteins. PorB is imported into mitochondria through the general translocase TOM but, unexpectedly, is not recognized by the SAM sorting machinery, usually required for the assembly of β-barrel proteins in the mitochondrial outer membrane. PorB integrates into the mitochondrial inner membrane, leading to the breakdown of ΔΨm. The PorB channel is regulated by nucleotides and an isogenic PorB mutant defective in ATP-binding failed to induce ΔΨm loss and apoptosis, demonstrating that dissipation of ΔΨm is a requirement for cell death caused by neisserial infection. PorB is a bacterial porin that plays an important role in the pathogenicity of Neisseria gonorrhoeae. Upon infection with these bacteria, PorB is transported into mitochondria of infected cells, causing the loss of mitochondrial membrane potential and eventually leading to apoptotic cell death. Here, we show that PorB enters mitochondria through the TOM complex, similar to other mitochondria-targeted proteins, but then bypasses the SAM complex machinery that assembles all other porin-like proteins into the outer mitochondrial membrane. This leads to the accumulation of PorB in the intermembrane space and the integration of a fraction of PorB into the inner mitochondrial membrane (IMM). In the IMM, ATP-regulated pores are formed, leading to dissipation of membrane potential and the loss of cristae structure in affected mitochondria, the necessary first steps in induction of apoptosis. Our work offers, for the first time, a detailed analysis of the mechanism by which PorB targets and damages host cell mitochondria.
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Affiliation(s)
- Vera Kozjak-Pavlovic
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | | | - Michael Meinecke
- Department of Biology/Chemistry, Division of Biophysics, University of Osnabrück, Osnabrück, Germany
| | - Oliver Kepp
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Katharina Ross
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Krishnaraj Rajalingam
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Anke Harsman
- Protein Purification Core Facility, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Eva Hauf
- Microscopy Core Facility, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Volker Brinkmann
- Microscopy Core Facility, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Dirk Günther
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Ines Herrmann
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Robert Hurwitz
- Protein Purification Core Facility, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Joachim Rassow
- Institute for Physiological Chemistry, Ruhr-University Bochum, Bochum, Germany
| | - Richard Wagner
- Department of Biology/Chemistry, Division of Biophysics, University of Osnabrück, Osnabrück, Germany
| | - Thomas Rudel
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
- * E-mail:
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Kepp O, Gottschalk K, Churin Y, Rajalingam K, Brinkmann V, Machuy N, Kroemer G, Rudel T. Bim and Bmf synergize to induce apoptosis in Neisseria gonorrhoeae infection. PLoS Pathog 2009; 5:e1000348. [PMID: 19300516 PMCID: PMC2654407 DOI: 10.1371/journal.ppat.1000348] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Accepted: 02/25/2009] [Indexed: 11/18/2022] Open
Abstract
Bcl-2 family proteins including the pro-apoptotic BH3-only proteins are central regulators of apoptotic cell death. Here we show by a focused siRNA miniscreen that the synergistic action of the BH3-only proteins Bim and Bmf is required for apoptosis induced by infection with Neisseria gonorrhoeae (Ngo). While Bim and Bmf were associated with the cytoskeleton of healthy cells, they both were released upon Ngo infection. Loss of Bim and Bmf from the cytoskeleton fraction required the activation of Jun-N-terminal kinase-1 (JNK-1), which in turn depended on Rac-1. Depletion and inhibition of Rac-1, JNK-1, Bim, or Bmf prevented the activation of Bak and Bax and the subsequent activation of caspases. Apoptosis could be reconstituted in Bim-depleted and Bmf-depleted cells by additional silencing of antiapoptotic Mcl-1 and Bcl-XL, respectively. Our data indicate a synergistic role for both cytoskeletal-associated BH3-only proteins, Bim, and Bmf, in an apoptotic pathway leading to the clearance of Ngo-infected cells. A variety of physiological death signals, as well as pathological insults, trigger apoptosis, a genetically programmed form of cell death. Pathogens often induce host cell apoptosis to establish a successful infection. Neisseria gonorrhoeae (Ngo), the etiological agent of the sexually transmitted disease gonorrhoea, is a highly adapted obligate human-specific pathogen and has been shown to induce apoptosis in infected cells. Here we unveil the molecular mechanisms leading to apoptosis of infected cells. We show that Ngo-mediated apoptosis requires a special subset of proapoptotic proteins from the group of BH3-only proteins. BH3-only proteins act as stress sensors to translate toxic environmental signals to the initiation of apoptosis. In a siRNA-based miniscreen, we found Bim and Bmf, BH3-only proteins associated with the cytoskeleton, necessary to induce host cell apoptosis upon infection. Bim and Bmf inactivated different inhibitors of apoptosis and thereby induced cell death in response to infection. Our data unveil a novel pathway of infection-induced apoptosis that enhances our understanding of the mechanism by which BH3-only proteins control apoptotic cell death.
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Affiliation(s)
- Oliver Kepp
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Kathleen Gottschalk
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Yuri Churin
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Krishnaraj Rajalingam
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Volker Brinkmann
- Core Facility for Microscopy, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Nikolaus Machuy
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Guido Kroemer
- INSERM, U848, Institute Gustave Roussy, Université Paris Sud, Paris, France
| | - Thomas Rudel
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Biozentrum, University of Würzburg, Department of Microbiology, Würzburg, Germany
- * E-mail:
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Criss AK, Seifert HS. Neisseria gonorrhoeae suppresses the oxidative burst of human polymorphonuclear leukocytes. Cell Microbiol 2008; 10:2257-70. [PMID: 18684112 PMCID: PMC2692872 DOI: 10.1111/j.1462-5822.2008.01205.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Symptomatic infection with Neisseria gonorrhoeae (Gc) results in a potent polymorphonuclear leukocyte (PMN)-driven inflammatory response, but the mechanisms by which Gc withstands PMN attack are poorly defined. Here we report that Gc can suppress the PMN oxidative burst, a central component of the PMN antimicrobial arsenal. Primary human PMNs remained viable after exposure to liquid-grown, exponential-phase, opacity-associated protein (Opa)-negative Gc of strains FA1090 and MS11 but did not generate reactive oxygen species (ROS), even after bacterial opsonization. Liquid-grown FA1090 Gc expressing OpaB, an Opa protein previously correlated with PMN ROS production, elicited a minor PMN oxidative burst. PMN ROS production in response to Opa(-) and OpaB+ Gc was markedly enhanced if bacteria were agar-grown or if liquid-grown bacteria were heat-killed. Liquid-grown Opa(-) Gc inhibited the PMN oxidative burst elicited by isogenic dead bacteria, formylated peptides or Staphylococcus aureus but did not inhibit PMN ROS production by OpaB+ Gc or phorbol esters. Suppression of the oxidative burst required Gc-PMN contact and bacterial protein synthesis but not phagocytosis. These results suggest that viable Gc directly inhibits PMN signalling pathways required for induction of the oxidative burst, which may contribute to gonococcal pathogenesis during inflammatory stages of gonorrhoeal disease.
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Affiliation(s)
- Alison K Criss
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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Siroy A, Mailaender C, Harder D, Koerber S, Wolschendorf F, Danilchanka O, Wang Y, Heinz C, Niederweis M. Rv1698 of Mycobacterium tuberculosis represents a new class of channel-forming outer membrane proteins. J Biol Chem 2008; 283:17827-37. [PMID: 18434314 PMCID: PMC2440620 DOI: 10.1074/jbc.m800866200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 04/03/2008] [Indexed: 11/06/2022] Open
Abstract
Mycobacteria contain an outer membrane composed of mycolic acids and a large variety of other lipids. Its protective function is an essential virulence factor of Mycobacterium tuberculosis. Only OmpA, which has numerous homologs in Gram-negative bacteria, is known to form channels in the outer membrane of M. tuberculosis so far. Rv1698 was predicted to be an outer membrane protein of unknown function. Expression of rv1698 restored the sensitivity to ampicillin and chloramphenicol of a Mycobacterium smegmatis mutant lacking the main porin MspA. Uptake experiments showed that Rv1698 partially complemented the permeability defect of the M. smegmatis porin mutant for glucose. These results indicated that Rv1698 provides an unspecific pore that can partially substitute for MspA. Lipid bilayer experiments demonstrated that purified Rv1698 is an integral membrane protein that indeed produces channels. The main single channel conductance is 4.5 +/- 0.3 nanosiemens in 1 M KCl. Zero current potential measurements revealed a weak preference for cations. Whole cell digestion of recombinant M. smegmatis with proteinase K showed that Rv1698 is surface-accessible. Taken together, these experiments demonstrated that Rv1698 is a channel protein that is likely involved in transport processes across the outer membrane of M. tuberculosis. Rv1698 has single homologs of unknown functions in Corynebacterineae and thus represents the first member of a new class of channel proteins specific for mycolic acid-containing outer membranes.
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Affiliation(s)
- Axel Siroy
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Rechner C, Kühlewein C, Müller A, Schild H, Rudel T. Host Glycoprotein Gp96 and Scavenger Receptor SREC Interact with PorB of Disseminating Neisseria gonorrhoeae in an Epithelial Invasion Pathway. Cell Host Microbe 2007; 2:393-403. [DOI: 10.1016/j.chom.2007.11.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 08/12/2007] [Accepted: 10/02/2007] [Indexed: 10/22/2022]
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Kühlewein C, Rechner C, Meyer TF, Rudel T. Low-phosphate-dependent invasion resembles a general way for Neisseria gonorrhoeae to enter host cells. Infect Immun 2006; 74:4266-73. [PMID: 16790801 PMCID: PMC1489691 DOI: 10.1128/iai.00215-06] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Obligate human-pathogenic Neisseria gonorrhoeae expresses numerous variant surface proteins mediating adherence to and invasion of target cells. The invariant major outer membrane porin PorB of serotype A (P.IA) gonococci triggers invasion into Chang cells only if the medium is devoid of phosphate. Since gonococci expressing PorB(IA) are frequently isolated from patients with severe disseminating infections, the interaction initiated by the porin may be of major relevance for the development of this serious disease. Here, we investigated the low-phosphate-dependent invasion and compared it to the well-known pathways of entry initiated by Opa proteins. P.IA-triggered invasion requires clathrin-coated pit formation and the action of actin and Rho GTPases. However, in contrast to Opa-initiated invasion via heparan sulfate proteoglycans, microtubules, acidic sphingomyelinase, phosphatidylinositol 3-kinase, and myosin light chain kinase are not involved in this entry pathway. Nor are Src kinases required, as they are in invasion, e.g., via the CEACAM3 receptor. Invasion by PorB(IA) occurs in a wide spectrum of cell types, such as primary human epithelial and endothelial cells and in cancer cells of human and animal origin. Low-phosphate-dependent invasion is thus a pathway of gonococcal entry distinct from Opa-mediated invasion.
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Affiliation(s)
- Christiane Kühlewein
- Max Planck Institute for Infection Biology, Department of Molecular Biology, Schumannstr. 21/22, D-10117 Berlin, Germany
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Mildiner-Earley S, Miller VL. Characterization of a novel porin involved in systemic Yersinia enterocolitica infection. Infect Immun 2006; 74:4361-5. [PMID: 16790812 PMCID: PMC1489722 DOI: 10.1128/iai.00154-06] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Yersinia enterocolitica is an enteric pathogen capable of causing systemic disease in a murine model. We have identified a novel protein, systemic factor protein A (SfpA), conserved in other pathogenic bacteria that is involved in systemic disease. Analysis of bacterial colonization revealed that a DeltasfpA strain is defective in mesenteric lymph node colonization. Bioinformatics and functional studies suggest that SfpA is a porin.
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Affiliation(s)
- Shirly Mildiner-Earley
- Department of Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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Lindbäck E, Islam S, Unemo M, Lang C, Wretlind B. Transformation of ciprofloxacin-resistant Neisseria gonorrhoeae gyrA, parE and porB1b genes. Int J Antimicrob Agents 2006; 28:206-11. [PMID: 16872806 DOI: 10.1016/j.ijantimicag.2006.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 04/06/2006] [Accepted: 04/07/2006] [Indexed: 11/25/2022]
Abstract
In several transformation experiments, we have shown that introduction of an alteration in GyrA at position 95 of a ciprofloxacin-susceptible Neisseria gonorrhoeae strain (minimum inhibitory concentration (MIC) 0.008 mg/L) increases the MIC to 0.064 mg/L. Two alterations (positions 91 and 95) increase the MIC to 0.125-0.25 mg/L. Transformants with ciprofloxacin MICs of 0.5-16 mg/L were obtained from a moderately ciprofloxacin-resistant strain (MIC 0.25 mg/L). These transformants had alterations in the gene for PorB1b and probably other genes. In one transformant, an alteration in ParE was also introduced, which probably contributed to ciprofloxacin resistance. The ciprofloxacin-resistant transformants had the donor porB1b sequence, and most of them also had altered serovars. We conclude that alterations in N. gonorrhoeae PorB1b could be involved in ciprofloxacin resistance.
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Affiliation(s)
- Emma Lindbäck
- Division of Clinical Bacteriology, Department of Laboratory Medicine, Karolinska Institute, F82 Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden.
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Janowicz D, Luke NR, Fortney KR, Katz BP, Campagnari AA, Spinola SM. Expression of OmpP2A and OmpP2B is not required for pustule formation by Haemophilus ducreyi in human volunteers. Microb Pathog 2006; 40:110-5. [PMID: 16426809 DOI: 10.1016/j.micpath.2005.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 11/24/2005] [Accepted: 11/29/2005] [Indexed: 11/25/2022]
Abstract
Haemophilus ducreyi express two porin proteins, termed OmpP2A and OmpP2B. To test whether expression of OmpP2A and OmpP2B was necessary for virulence in humans, eight volunteers were experimentally infected with the parent (35000HP) in one arm and a double OmpP2A OmpP2B mutant (35000HP::P2AB) in the other arm. The pustule formation rates were 58.3% (95% CI, 33.2-83.5%) for the parent and 41.7% (95% CI, 19.3-64.0%) for the mutant (P=0.25). Biopsy of 35000HP and 35000HP::P2AB-infected sites yielded similar amounts of bacteria in quantitative culture. These results indicate that expression of OmpP2A and OmpP2B is not necessary to initiate disease or to progress to pustule formation in humans.
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Affiliation(s)
- Diane Janowicz
- Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
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31
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Zhu W, Thomas CE, Chen CJ, Van Dam CN, Johnston RE, Davis NL, Sparling PF. Comparison of immune responses to gonococcal PorB delivered as outer membrane vesicles, recombinant protein, or Venezuelan equine encephalitis virus replicon particles. Infect Immun 2005; 73:7558-68. [PMID: 16239559 PMCID: PMC1273881 DOI: 10.1128/iai.73.11.7558-7568.2005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Porin (PorB) is a major outer membrane protein produced by all Neisseria gonorrhoeae strains and has been a focus of intense interest as a vaccine candidate. In this study, the immunogenicity of PorB in mice was investigated after several immunization regimens. Outer membrane vesicles (OMV), recombinant renatured PorB (rrPorB), and PorB-expressing Venezuelan equine encephalitis (VEE) virus replicon particles (PorB VRP) were delivered intranasally (i.n.) or subcutaneously (s.c.) into the dorsal area or the hind footpad in three-dose schedules; the PorB VRP-immunized mice were given a single additional booster dose of rrPorB in Ribi adjuvant. Different delivery systems and administration routes induced different immune responses. Mice immunized s.c. with rrPorB in Ribi had the highest levels of PorB-specific serum immunoglobulin G (IgG) by enzyme-linked immunosorbent assay. Surprisingly, there was an apparent Th1 bias, based on IgG1/IgG2a ratios, after immunization with rrPorB in Ribi in the footpad while the same vaccine given in the dorsal area gave a strongly Th2-biased response. PorB VRP-immunized mice produced a consistent Th1 response with a high gamma interferon response in stimulated splenic lymphocytes and very low IgG1/IgG2a ratios. Immunization by OMV delivered i.n. was the only regimen that resulted in a serum bactericidal response, and it generated an excellent mucosal IgA response. Serum from mice immunized with rrPorB preferentially recognized the surface of whole gonococci expressing a homologous PorB, whereas serum from PorB VRP-immunized mice had relatively low whole-cell binding activity but recognized both heterologous and homologous PorB equally. The data resulting from this direct comparison suggested that important aspects of the immune response can be manipulated by altering the form of the antigen and its delivery. This information coupled with an understanding of protective antigonococcal immune responses will enable the design of the optimal vaccine for N. gonorrhoeae.
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Affiliation(s)
- Weiyan Zhu
- University of North Carolina at Chapel Hill, Department of Medicine, Division of Infectious Disease Research, 8341 Medical Biomolecular Research Bldg., 103 Mason Farm Road, CB# 7031, Chapel Hill, NC 27599, USA
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Song Q, Liao F, Ye S, Cui B, Xiong P. Construtcion of Neisseria gonorrhoeae porin B plasmid recombinant and its expression in E. coli. JOURNAL OF HUAZHONG UNIVERSITY OF SCIENCE AND TECHNOLOGY. MEDICAL SCIENCES = HUA ZHONG KE JI DA XUE XUE BAO. YI XUE YING DE WEN BAN = HUAZHONG KEJI DAXUE XUEBAO. YIXUE YINGDEWEN BAN 2005; 25:251-3. [PMID: 16201262 DOI: 10.1007/bf02828133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A prokaryotic expression recombinant plasmid pET-PIB to express porin B (PIB) of Neisseria gonorrhoeae in E. coli DE3 was constructed in order to provide a basis of research in detection, prophylactic and therapeutic vaccine against the pathogen infection. The gene encoding PIB was amplified by PCR from Neisseria gonorrhoeae and cloned into prokaryotic expression plasmid pET-28a(+) to construct a pET-PIB recombinant, which was verified by restriction endonuclease and DNA sequencing. Protein PIB was expressed in E. coli DE3 induced with IPTG. The antigenicity of the expressed protein was evaluated by indirect ELISA. Rabbits were immunized with the protein and serum was collected after immunization. To assess the immunogenicity of the protein, the titer of serum to protein PIB was determined by ELISA. DNA sequence analysis showed that the nucleic acid sequence of PIB gene was 99.28% of homology compared with that (NGPIB18) published in GenBank. A 41 kD fused protein was detected by SDS-PAGE and was proven to have reactivity with anti-PIB polyclonal antibody from mouse. A polyclonal antibody to PIB of 1:4000 titer determined by indirect EISA was obtained from rabbit immunized with the purified product. Recombinant plasmid encoding PIB of Neisseria gonorrhoeae was constructed. Protein PIB with antigenicity and immunogenicity was successfully expressed.
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Affiliation(s)
- Qifa Song
- Department of Biopathogen, School of Basic Medical Sciences, Tong ji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Jordan PW, Snyder LAS, Saunders NJ. Strain-specific differences in Neisseria gonorrhoeae associated with the phase variable gene repertoire. BMC Microbiol 2005; 5:21. [PMID: 15857514 PMCID: PMC1097732 DOI: 10.1186/1471-2180-5-21] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Accepted: 04/27/2005] [Indexed: 12/02/2022] Open
Abstract
Background There are several differences associated with the behaviour of the four main experimental Neisseria gonorrhoeae strains, FA1090, FA19, MS11, and F62. Although there is data concerning the gene complements of these strains, the reasons for the behavioural differences are currently unknown. Phase variation is a mechanism that occurs commonly within the Neisseria spp. and leads to switching of genes ON and OFF. This mechanism may provide a means for strains to express different combinations of genes, and differences in the strain-specific repertoire of phase variable genes may underlie the strain differences. Results By genome comparison of the four publicly available neisserial genomes a revised list of 64 genes was created that have the potential to be phase variable in N. gonorrhoeae, excluding the opa and pilC genes. Amplification and sequencing of the repeat-containing regions of these genes allowed determination of the presence of the potentially unstable repeats and the ON/OFF expression state of these genes. 35 of the 64 genes show differences in the composition or length of the repeats, of which 28 are likely to be associated with phase variation. Two genes were expressed differentially between strains causing disseminated infection and uncomplicated gonorrhoea. Further study of one of these in a range of clinical isolates showed this association to be due to sample size and is not maintained in a larger sample. Conclusion The results provide us with more evidence as to which genes identified through comparative genomics are indeed phase variable. The study indicates that there are large differences between these four N. gonorrhoeae strains in terms of gene expression during in vitro growth. It does not, however, identify any clear patterns by which previously reported behavioural differences can be correlated with the phase variable gene repertoire.
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Affiliation(s)
- Philip W Jordan
- Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Lori AS Snyder
- Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Nigel J Saunders
- Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
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Liao F, Song Q, Wan M. Construction of prokaryotic expression plasmid of fusion protein including porin A and porin B of Neisseria gonorrhoeae and its expression in E. coli. Curr Med Sci 2004; 24:417-20. [PMID: 15641680 DOI: 10.1007/bf02831096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Indexed: 05/01/2023]
Abstract
In order to provide a rational research basis for clinical detection and genetic engineering vaccine, plasmid pET-28a (+) encoding both Porin gene PIA and PIB of Neisseria gonorrhoeae was constructed and a fusion protein in E. coli DE3 expressed. The fragments of PIA and PIB gene of Neisseria gonorrhoeae were amplified and cloned into prokaryotic expression plasmid pET-28a (+) with double restriction endonuclease cut to construct recombinant pET-PIB-PIA. The recombinant was verified with restriction endonuclease and sequenced and transformed into E. coli DE3 to express the fusion protein PIB-PIA after induced with IPTG. The results showed PIA-PIB fusion DNA fragment was proved correct through sequencing. A 67 kD (1 kD= 0.992 1 ku) fusion protein had been detected by SDS-PAGE. It was concluded that the fusion protein was successively expressed.
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Affiliation(s)
- Fang Liao
- Department of Microbiology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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35
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Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are Gram-negative pathogenic bacteria responsible for bacterial meningitis and septicemia, and the sexually transmitted disease gonorrhea, respectively. Porins are the most represented outer membrane proteins in the pathogenic Neisseria species, functioning as pores for the exchange of ions, and are characterized by a trimeric beta-barrel structure. Neisserial porins have been shown to act as adjuvants in the immune response via activation of B cells and other antigen-presenting cells (APCs). Their effect on the immune response is mediated by upregulation of the costimulatory molecule B7-2 (CD86) on the surface of APCs, an effect that is Toll-like receptor 2- and MyD88-dependent. The effect of neisserial porins on the immune system also involves interaction with components of the complement cascade. Furthermore, neisserial porins co-localize with mitochondria of target cells, where they appear to modulate apoptosis.
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Affiliation(s)
- Paola Massari
- Department of Medicine, Division of Infectious Diseases, Boston University School of Medicine, Boston, MA 02118, USA
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36
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Nassif X, Bourdoulous S, Eugène E, Couraud PO. How do extracellular pathogens cross the blood-brain barrier? Trends Microbiol 2002; 10:227-32. [PMID: 11973156 DOI: 10.1016/s0966-842x(02)02349-1] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Bacterial invasion of the meninges can occur as a consequence of bloodstream invasion by some bacterial pathogens. Bacteria enter the central nervous system following a direct interaction with the luminal side of the cerebral endothelium, which constitutes the blood-brain barrier. To breach the barriers protecting the brain, extracellular pathogens must cross a monolayer of tight junction-expressing endothelial or epithelial cells. The limited number of pathogens capable of crossing these tight barriers and invading the meninges suggests that they display very specific attributes. For Neisseria meningitidis, type IV pili have been identified as being essential for meningeal invasion and it is believed other, as-yet-unidentified factors are also involved.
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Affiliation(s)
- Xavier Nassif
- INSERM U570, Faculté de Médecine Necker-Enfants Malades, Université Paris V, 156 Rue de Vaugirard, 75015 Paris, France.
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37
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Eugène E, Hoffmann I, Pujol C, Couraud PO, Bourdoulous S, Nassif X. Microvilli-like structures are associated with the internalization of virulent capsulatedNeisseria meningitidisinto vascular endothelial cells. J Cell Sci 2002; 115:1231-41. [PMID: 11884522 DOI: 10.1242/jcs.115.6.1231] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial pathogens are internalized into non-phagocytic cells either by a zipper mechanism involving a direct contact between a bacterial ligand and a cellular receptor or a trigger mechanism secondary to the formation of membrane ruffles. Here we show that internalization of capsulated Neisseria meningitidis within endothelial cells following type IV pilus-mediated adhesion is associated with the formation of cellular protrusions at the site of bacterial attachment. These protrusions, like microvilli, are highly enriched in ezrin and moesin, two members of the ERM(ezrin/radixin/moesin) family, whereas vinculin and paxillin are absent. ERM-binding transmembrane proteins, such as CD44, and cortical actin polymerization colocalized within these membrane protrusions. Expression of dominant-negative ezrin largely prevented cortical actin polymerization, thus confirming the role of this molecule in bacteria-induced cytoskeletal modifications. Moreover, using selective inhibitors and dominant-negative mutants of the Rho family GTPases, we show that bacteria-induced actin polymerization required the activation of both Rho and Cdc42 but not of Rac1. Whereas GTPase inhibition dramatically reduced actin polymerization at the site of bacterial attachment, ezrin recruitment was not affected, indicating that bacterial adhesion promotes ezrin recruitment independently of the activity of the Rho-GTPases. Furthermore, GTPase inhibition largely reduced N. meningitidis entry into endothelial cells without affecting adhesion. We thus propose that following pilus-mediated adhesion, capsulated N. meningitidis recruit ERM-binding transmembrane proteins, as well as ezrin and moesin, and that both Rho and Cdc42 are critical for the subsequent cytoskeletal modifications responsible for the formation of microvilli-like cellular protrusions and bacterial internalization.
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Affiliation(s)
- Emmanuel Eugène
- INSERM U411, Faculté de Médecine Necker-Enfants Malades, Université René Descartes, Paris, France. CNRS UPR 415, Institut Cochin de Génétique Moléculaire, Paris, France
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38
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Santiviago CA, Toro CS, Bucarey SA, Mora GC. A chromosomal region surrounding the ompD porin gene marks a genetic difference between Salmonella typhi and the majority of Salmonella serovars. MICROBIOLOGY (READING, ENGLAND) 2001; 147:1897-1907. [PMID: 11429466 DOI: 10.1099/00221287-147-7-1897] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this work it is shown that the majority of Salmonella serovars most frequently associated with the systemic infection of vertebrate hosts produce a major outer-membrane porin, OmpD. However, OmpD is absent from the outer-membrane protein profiles of Salmonella typhi strain Ty2 and 26 clinical isolates of S. typhi examined by SDS-PAGE. To determine whether the ompD gene is present in S. typhi, primers internal to the ompD coding sequence were used to amplify the gene by PCR. With the exception of S. typhi strains, the ompD gene was amplified from the genomes of all Salmonella serovars tested. Consistently, a specific ompD probe did not hybridize with DNA isolated from the S. typhi strains. Taken together, these results demonstrate that S. typhi does not produce OmpD due to the absence of the ompD gene. Furthermore, it was investigated whether the deletion of ompD extended to smvA. This gene is adjacent to ompD in the Salmonella typhimurium chromosome and encodes a protein involved in the resistance to methyl viologen, a superoxide-generating agent. Although PCR failed to amplify the smvA gene from the S. typhi strain Ty2 genome, it was possible to amplify it from the chromosome of the clinical strains. On the other hand, hybridization analyses showed that the smvA gene is present in all the S. typhi strains tested. In contrast to the other Salmonella serovars, S. typhi strain Ty2 and the clinical isolates showed sensitivity to methyl viologen, suggesting that smvA gene is inactive in S. typhi. In conclusion, the ompD-smvA region is variable in structure among Salmonella serovars. It is hypothesized that the absence of ompD may suggest a role in host specificity.
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Affiliation(s)
- Carlos A Santiviago
- Laboratorio de Microbiologı́a, Departamento de Genética Molecular y Microbiologı́a, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda no. 340, Santiago, Chile1
| | - Cecilia S Toro
- Laboratorio de Microbiologı́a, Departamento de Genética Molecular y Microbiologı́a, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda no. 340, Santiago, Chile1
| | - Sergio A Bucarey
- Laboratorio de Microbiologı́a, Departamento de Genética Molecular y Microbiologı́a, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda no. 340, Santiago, Chile1
| | - Guido C Mora
- Laboratorio de Microbiologı́a, Departamento de Genética Molecular y Microbiologı́a, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda no. 340, Santiago, Chile1
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Abstract
The closely related bacterial pathogens Neisseria gonorrhoeae (gonococci, GC) and N. meningitidis (meningococci, MC) initiate infection at human mucosal epithelia. Colonization begins at apical epithelial surfaces with a multistep adhesion cascade, followed by invasion of the host cell, intracellular persistence, transcytosis, and exit. These activities are modulated by the interaction of a panoply of virulence factors with their cognate host cell receptors, and signals are sent from pathogen to host and host to pathogen at multiple stages of the adhesion cascade. Recent advances place us on the verge of understanding the colonization process at a molecular level of detail. In this review we describe the Neisseria virulence factors in the context of epithelial cell biology, placing special emphasis on the signaling functions of type IV pili, pilus-based twitching motility, and the Opa and Opc outermembrane adhesin/invasin proteins. We also summarize what is known about bacterial intracellular trafficking and growth. With the accelerated integration of tools from cell biology, biochemistry, biophysics, and genomics, experimentation in the next few years should bring unprecedented insights into the interactions of Neisseriae with their host.
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Affiliation(s)
- A J Merz
- Department of Molecular Microbiology & Immunology, L220, Oregon Health Sciences University, Portland, Oregon 97201-3098, USA
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40
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Abstract
Neisseria gonorrhoeae employs diverse strategies with which to adhere to and invade host cells during the course of infection. These primary encounters provide means by which biologically active molecules can be efficiently targeted to disrupt or exploit normal host cell metabolism and immune response elements, which in turn leads to the pathological responses characteristic of gonococcal disease. Current studies have begun to elucidate in detail the molecular interactions orchestrating these processes and the signaling events that they provoke.
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Affiliation(s)
- M Koomey
- The Biotechnology Centre of Oslo, University of Oslo, PO Box 1125 Blindern, N-0349, Oslo, Norway.
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41
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Lorenzen DR, Günther D, Pandit J, Rudel T, Brandt E, Meyer TF. Neisseria gonorrhoeae porin modifies the oxidative burst of human professional phagocytes. Infect Immun 2000; 68:6215-22. [PMID: 11035728 PMCID: PMC97702 DOI: 10.1128/iai.68.11.6215-6222.2000] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A hallmark of infection with the gram-negative bacterium Neisseria gonorrhoeae is the local infiltration and subsequent activation of polymorphonuclear neutrophils. Several gonococcal outer membrane proteins are involved in the interaction with and the activation of these phagocytes, including gonococcal porin, the most abundant protein in the outer membrane. Previous work suggests that this porin plays a role in various cellular processes, including inhibiting neutrophils activation and phagosome maturation in professional phagocytes. Here we investigated the ability of porin to modify the oxidative metabolism of human peripheral blood neutrophils and monocytes in response to particulate stimuli (including live gonococci) and soluble agents. The activation of the oxidative metabolism was determined by chemiluminescence amplified with either luminol or lucigenin. We found that treatment of the phagocytes with porin inhibits the release of reactive oxygen species measured as luminol-enhanced chemiluminescence in response to zymosan, latex particles, and gonococci. The engulfment of these particles was not, however, affected by porin treatment. Similar effects of porin on the chemiluminescence response were observed in cytochalasin B-treated neutrophils exposed to the soluble chemotactic peptide N-formylmethionyl-leucyl-phenylalanine. This indicates that porin selectively inhibits granule fusion with those cellular membranes that are in direct contact with porin, namely, the phagosomal and plasma membranes. This porin-induced downregulation of oxidative metabolism may be a potent mechanism by which gonococci modulate oxygen-dependent reactions by activated phagocytes at inflammation sites.
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Affiliation(s)
- D R Lorenzen
- Abteilung Molekulare Biologie, Max-Planck-Institut für Infektionsbiologie, D-10117 Berlin, Germany
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42
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Pujol C, Eugène E, Morand P, Nassif X. Do pathogenic neisseriae need several ways to modify the host cell cytoskeleton? Microbes Infect 2000; 2:821-7. [PMID: 10955963 DOI: 10.1016/s1286-4579(00)90367-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens which have to interact with mucosa and/or cellular barriers for their life cycle. Even though they both give rise to dramatically different diseases, most of the mechanisms mediating cellular interactions are common to N. meningitidis and N. gonorrhoeae. This suggests that bacterial cell interactions may be essential not only for pathogenesis but also for other aspects of the bacterial life cycle that are common to both N. meningitidis and N. gonorrhoeae. Opacity proteins and pili are two major components identified as transducing signals to host cells, thus leading to cytoskeleton modifications. This manuscript will review the recent developments concerning the mechanisms mediating cellular interactions of pathogenic Neisseria and will tentatively put them into the perspective of pathogenesis and bacterial life cycle.
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Affiliation(s)
- C Pujol
- INSERM U411, Faculté de Médecine Necker-Enfants Malades, Université René Descartes, Paris, France
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43
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Fudyk TC, Maclean IW, Simonsen JN, Njagi EN, Kimani J, Brunham RC, Plummer FA. Genetic diversity and mosaicism at the por locus of Neisseria gonorrhoeae. J Bacteriol 1999; 181:5591-9. [PMID: 10482498 PMCID: PMC94077 DOI: 10.1128/jb.181.18.5591-5599.1999] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The por genes of the predominant serovars of Neisseria gonorrhoeae circulating in a high-frequency transmitter core group located in Nairobi, Kenya, were examined for nucleotide sequence polymorphism. The level of por gene diversity did not differ significantly between core group-derived gonococcal strains and gonococcal strains originating elsewhere. However, por mosaicism appeared to be more frequent among core group-derived strains, suggesting that recombination of different por sequences may be a important strategy by which N. gonorrhoeae generates por gene diversity within core group populations. Despite extensive sequence variability, por expressed by gonococcal isolates of different geographic origin exhibited conserved patterns of nucleotide change, suggesting that diversity among por alleles may also be finite.
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Affiliation(s)
- T C Fudyk
- Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
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Nassif X, Pujol C, Morand P, Eugène E. Interactions of pathogenic Neisseria with host cells. Is it possible to assemble the puzzle? Mol Microbiol 1999; 32:1124-32. [PMID: 10383754 DOI: 10.1046/j.1365-2958.1999.01416.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens that have to interact with mucosa and/or cellular barriers for their life cycles to progress. Even though they both give rise to dramatically different diseases, the use of in vitro models has shown that most of the mechanisms mediating cellular interactions are common to N. meningitidis and N. gonorrhoeae. This suggests that bacterial cell interactions may be essential not only for pathogenesis but also for other aspects of the bacterial life cycle that are common to both N. meningitidis and N. gonorrhoeae. This manuscript will review the most recent developments concerning the mechanisms mediating cellular interaction of pathogenic Neisseria and will then try to put them into the perspective of pathogenesis and bacterial life cycle.
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Affiliation(s)
- X Nassif
- INSERM U411, Faculté de Médecine Necker-Enfants Malades, Université René Descartes, Paris, France.
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Abstract
Neisseria gonorrhoeae is a highly adapted human pathogen that utilises multiple adhesins to interact with a variety of host cell receptors. Recently, substantial progress has been made in unravelling the signalling events induced by N. gonorrhoae that can lead to cytoskeletal reorganisation, invasion or phagocytic uptake, intraphagosomal accommodation, nuclear signalling, cytokine/chemokine release and apoptosis.
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Affiliation(s)
- M Naumann
- Max-Planck-Institut für Infektionsbiologie Abteilung Molekulare Biologie Monbijou Str 2 10117 Berlin Germany
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